Search

Jacqueline Viegas,1 Helen Holtby,2 Kyle Runeckles,3 Elvira V Lang4 1Cardiac Diagnostic and Interventional Unit, Labatt Family Heart Centre, The Hospital for Sick Children, Toronto, Ontario, Canada; 2Department of Anesthesia, The Hospital for Sick Children, Toronto, Ontario, Canada; 3University Health Network Research Institute, Toronto, Ontario, Canada; 4Hypnalgesics, LLC, Brookline, MA, USACorrespondence: Jacqueline Viegas, Cardiac Diagnostic and Interventional Unit, Labatt Family Heart Centre, The Hospital for Sick Children, 555 University Ave, Toronto, Ontario, M5G1X8, Canada, Tel +1 416 659 4443, Fax +1 416 813 6404, Email jacqueline.viegas@sickkids.caPurpose: To assess the impact on children of self-hypnotic relaxation scripts read by trained staff prior to the induction of anesthesia and/or extubation on the periprocedural experience.Patients and Methods: A total of 160 children aged 7– 18 years undergoing a cardiac catheterization intervention under general anesthesia were randomized into 4 groups: (1) a pre-procedure (PP-script) read prior to entering the procedural room, (2) a script read prior to extubation (PX-Script), (3) both PP- and PX-Scripts read and (4) no script read. Anxiety and pain were rated on self-reported 0– 10 scales. The modified Yale Preoperative Anxiety Scale was used for preoperative anxiety. The effect of script reading was associated with outcomes by linear regression for continuous variables, and logistic regression for binary variables in two-sided tests at a significance level of 0.05. Results are given in odds ratios (OR) and 95% confidence intervals (CI).Results: Data were available for 158 patients. Reading the PP-Script prior to anesthesia was associated with a significant reduction in the use of intraoperative sedatives from 30% to 14% (OR 0.40; CI 0.18– 0.88; p = 0.02) by the anesthesiologists, who were blinded to group attribution until extubation. This was despite the children not self-reporting significantly lower levels of anxiety or pain. The PX-Script did not change outcomes. Among groups, there was no significant difference in room time, postoperative recovery time and pain.Conclusion: Reading a PP-Script for guidance in self-hypnotic relaxation can result in less need for intravenous sedation in the judgment of the anesthesiologist, independent of the children’s self-reported anxiety and pain. This raises interesting questions about subconscious patient–physician interactions affecting pain management.Clinicaltrials.gov Identifier: NCT02347748.Keywords: sedation, anesthesia, children, pain, anxiety

The immature coagulation system during infancy has age-related physiological differences in proteins that contribute to significant variation in heparin responsiveness through alterations in heparin-enhanced thrombin inhibition. The primary aim of this study was to evaluate the relationship between preoperative antithrombin (AT) activity and heparin responsiveness in neonates and infants undergoing congenital cardiac surgery. In this retrospective cohort study, neonates (aged 0-28 days) and infants (aged 29-365 days) undergoing congenital cardiac surgery in the 12-month period from October 2013 to 2014 were studied. The two age groups were compared for the primary endpoint of heparin response measured by the heparin sensitivity index (HSI), with heparin loading doses and heparin resistance being secondary endpoints. Multivariable linear regression analyses were used to explore the relationship between AT activity and heparin response measured by HSI. There were 122 infants and 19 neonates included in the study. After adjusting for low-molecular-weight heparin, unfractionated heparin, and platelet count, there was a significant relationship between AT activity and HSI (r = 0.44; P = 0.009). The median [interquartile range] HSI did not differ between neonates and infants (0.76 [0.69- 0.98] vs 0.89 [0.70-1.10] sec·unit−1·kg−1, respectively; median difference, 0.08; 95% confidence interval [CI], −0.01 to 0.17; P = 0.182), despite the mean (standard deviation) AT activity differing between age groups [60 (16)% vs 84 (18)%, respectively; mean difference, 24; 95% CI, 15 to 32; P < 0.001]. There was a moderate relationship between AT activity and heparin response measured by HSI. Comparing neonates and infants, there was similar heparin responsiveness measured by HSI despite differing AT activity levels. These findings should help guide the perioperative administration of exogenous AT to neonates and infants and suggest that, outside the neonatal period, preoperative AT activity may be used to identify children at risk of decreased heparin responsiveness.

The first Blalock-Taussig (BT) shunt was reported in 1944, and during the last 70 years, the procedure has evolved with the development of new materials and devices, and surgical approaches. It has, however, remained central to the palliation of neonates with complex congenital heart disease. The indications have expanded from the original aim of alleviating cyanosis and the pathophysiological results of chronic hypoxemia. They now include lesions with single ventricles, and rehabilitation of small pulmonary arteries. The physiology and hemodynamics of BT shunt circulations are very complex, and adverse hemodynamic events can be difficult to recognize. The consequences of shunt failure can be fatal, and the mortality (3-15%) and morbidity remain distressingly high even in the current era. Neonates undergoing BT shunt procedures or undergoing noncardiac surgery with this anatomy are challenging for the anesthesiologists to manage. There is a significant incidence of periprocedural cardiac arrest, often related to myocardial ischemia. A clear understanding of the anatomy and physiology is important. Any discussion of BT shunt in the current era has to include consideration of hypoplastic left heart syndrome and 'single ventricle' physiology.

The "hybrid procedure" is an alternative surgical palliation strategy for single ventricle congenital heart disease. The purported benefit is improved cognitive ability secondary to avoidance of cardiopulmonary bypass in the neonatal period when neuronal apoptosis is greater. It is unknown whether survival is improved after this procedure. Intraoperative hypotension is common in these patients, and we hypothesized that this hypotension was associated with mortality or morbidity.We reviewed the records of 58/58 patients undergoing a first-stage hybrid procedure from 2004 to 2010 in a tertiary pediatric academic centre. Risk factors for poor outcome and the association between intraoperative hypotension and morbidity or mortality were investigated.Average preoperative arterial blood pressure (ABP) [systolic/diastolic presented as mean (standard deviation)] were 68 (12.7) / 38 (9.4) mmHg. Post-induction ABP was 65 (15.2) / 37 (8.6) mmHg. The average intraoperative nadir of ABP was 45 (7.0) / 26 (4.8) mmHg. On return to the intensive care unit (ICU), the average ABP was 69 (13.7) / 38 (11.6) mmHg. The nadir lasted longer than ten minutes in 32/58 patients. The mortality at 48 hr, 60 days, and 12 months was 3/58 (5%), 10/58 (17%), and 15/58 (26%), respectively. Six patients returned to the ICU on extracorporeal membrane oxygenation (ECMO). There was a weak statistical correlation between the average mean and diastolic BP pre-induction and changes of20% in systolic and diastolic BP during the case.In this patient cohort, we can show an association between short periods of intraoperative hypotension and mortality or return to the ICU on ECMO, but the importance of this is not certain.

This article reviews potential pediatric applications of 3 new technologies. (1) Pulse oximetry-based hemoglobin determination: Hemoglobin determination using spectrophotometric methods recently has been introduced in adults with varied success. This non-invasive and continuous technology may avoid venipuncture and unnecessary transfusion in children undergoing surgery with major blood loss, premature infants undergoing unexpected and complicated emergency surgery, and children with chronic illness. (2) Continuous cardiac output monitoring: In adults, advanced hemodynamic monitoring such as continuous cardiac output monitoring has been associated with better surgical outcomes. Although it remains unknown whether similar results are applicable to children, current technology enables the monitoring of cardiac output non-invasively and continuously in pediatric patients. It may be important to integrate the data about cardiac output with other information to facilitate therapeutic interventions. (3) Anesthesia information management systems: Although perioperative electronic anesthesia information management systems are gaining popularity in operating rooms, their potential functions may not be fully appreciated. With advances in information technology, anesthesia information management systems may facilitate bedside clinical decisions, administrative needs, and research in the perioperative setting.

The negative effects of long-term storage of allogeneic red blood cells (RBCs) on outcomes in adult cardiac surgery have been established, but evidence of a similar effect in pediatric cardiac surgery is limited.The weighted average duration of storage for RBC units used in 1,225 pediatric cardiac operations was determined. Operations were divided into high RBC use (more than 4 units or more than 150 mL/kg) or low RBC use. For both categories, associations between storage duration and surgical outcomes, adjusted for relevant patient characteristics, were evaluated.High RBC use was associated with higher surgical complexity. Storage duration for patients who received low RBC volumes was not associated with surgical outcomes. For patients with high RBC transfusion volumes, longer storage duration (per day) was associated with higher odds of bleeding complications (odds ratio 1.029, p=0.07), renal insufficiency (odds ratio 1.085, p=0.001), higher inotrope score after surgery (12 to 24 hours +0.08, p=0.002; 24 to 48 hours +0.07, p0.001), greater chest tube drainage (24 hours +1.5 mL/kg, p0.001), longer postoperative hospitalization (+0.3 days p=0.02), and increased in-hospital mortality (odds ratio 1.054, p=0.03). Effects of RBC transfusions on postoperative bleeding were greatest for storage duration longer than 14 days.The freshest RBC units available should be used for pediatric cardiac operations expected to require more than 4 units or more than 150 mL/kg of allogeneic RBC transfusions, with no units more than 14 days old being transfused whenever possible.

We sought to determine whether the use of specific unfractionated heparin brands during cardiopulmonary bypass for pediatric cardiac surgery was associated with differences in postoperative outcomes, especially regarding the incidence of bleeding and thromboembolic complications.We compared postoperative outcomes for pediatric cardiac surgeries performed with Hepalean (Organon Teknika) to those performed with PPC heparin (Pharmaceutical Partners of Canada). Differences in clinical outcomes were determined in multivariable logistic and linear regression models adjusted for patients and surgery characteristics.In all, 903 operations were reviewed, 289 (32%) using Hepalean and 614 (68%) using PPC heparin. Patient demographics and surgical variables were comparable between groups. In multivariable regression models, adjusted for patients' characteristics, heparin use and choice of antifibrinolytic agents, the use of PPC heparin was associated with greater use of red blood cell transfusions in the first 48 postoperative hours (estimates +1.6 mL/kg, p0.001), increased odds of bleeding complications (odds ratio 3.8, p=0.04), thromboembolic complications (odds ratio 4.7, p=0.01), early unplanned reoperation (odds ratio 6.9, p=0.03), longer postoperative intensive care unit stay (estimate +3.2 days, p0.001), and longer hospital stay (estimate +3.6 days, p0.001).Brand of unfractionated heparin used during cardiopulmonary bypass for pediatric cardiac surgery was associated with bleeding complications and clinical outcomes. Different brands of unfractionated heparin should not be considered equivalent without proper validation in formal trials.

Background— Thrombosis, usually considered a serious but rare complication of pediatric cardiac surgery, has not been a major clinical and/or research focus in the past. Methods and Results— We noted 444 thrombi (66% occlusive, 60% symptomatic) in 171 of 1542 surgeries (11%). Factors associated with increased odds of thrombosis were age P =0.002), baseline oxygen saturation P =0.001), previous thrombosis (OR, 2.6; P =0.001), heart transplantation (OR, 4.1; P P =0.01), longer cumulative time with central lines (OR, 1.2 per 5-day equivalent; P P P P =0.02), and partially/fully occluding thrombi (OR, 14.3; P =0.001); indwelling access line in vessel (versus no access line) was associated with lower risk of serious complications (OR, 0.4; P =0.05). Thrombosis was associated with longer intensive care unit (+10.0 days; P P P P =0.002), and reoperation (OR, 2.5; P =0.003); and increased mortality (OR, 5.1; P P P =0.01), older age at surgery (OR, 1.2 per year; P =0.04), higher white blood cell count (OR, 1.1/10 9 cells per 1 mL; P =0.002), and lower fibrinogen (OR, 1.4/g/L; P =0.02) after surgery. Conclusions— Thrombosis affects a high proportion of children undergoing cardiac surgery and is associated with suboptimal outcomes. Increased awareness and effective prevention and detection strategies are needed.

Objective(s) To evaluate the measurement of cardiac output (CO) using continuous electrical bioimpedance cardiography (Physioflow; Neumedx, Philadelphia, PA) (CO PF ) with a simultaneous direct Fick measurement (CO FICK ) in children with congenital heart disease. Design A prospective cohort study comparing 2 methods of measurement of CO. Setting A quaternary university-affiliated pediatric hospital. Participants Children undergoing cardiac catheterization for clinical care. Interventions The Physioflow measured continuous real time CO in 15-second epochs and simultaneous measurement of cardiac output by direct Fick (with mass spectrometry to assess VO 2 ) were acquired. Measurements and Main Results Sixty-five patients were recruited, and data from 56 (25 males) were adequate for analysis. The median age at study was 3.5 years (range, 0.4-16.6 years), and the median body surface area was 0.62 m 2 (range, 0.31-1.71). There were 25 of 56 (45%) with univentricular physiology. A total of 19,228 Physioflow data points were available for the analysis of which 14,569 (76%) were valid; 96% of the invalid measurements were identified as artifacts by the device. The average cardiac index of valid measurements was 3.09 ± 0.72 L/min/m 2 . Compared with the Fick CO, the mean bias was −0.09 L/min, but the 95% limits of agreement were −3.20 to +3.01 L/min/m 2 . Consequently, only 20 of 56 (36%) of measurements were within 20%, and 31 of 56 (55%) of measurements were within 30% of each other. Conclusions Compared with measurements made by direct Fick, CO measured using the Physioflow device was unreliable in anesthetized children with congenital heart disease.

Summary Introduction: It is thought that patients with cardiomyopathy have an increased risk of cardiac arrest on induction of anesthesia, but there is little available data. The purpose of this study was to identify the incidence and potential risk factors for cardiac arrest upon induction of anesthesia in children with cardiomyopathy in our institution. Methods: A retrospective chart review was performed. Eligible patients included patients admitted between 1998 and 2008 with the International Statistical Classification of Disease code for cardiomyopathy (ICD-9 code 425) who underwent airway intervention for sedation or general anesthesia in the operating room, cardiac diagnostic and interventional unit (CDIU) or intensive care unit. Patients undergoing emergency airway intervention following cardiovascular collapse were excluded. For each patient, we recorded patient demographics, disease severity, anesthesia location, and anesthetic technique. Results: One hundred and twenty-nine patients with cardiomyopathy underwent a total of 236 anesthetic events, and four cardiac arrests were identified. One was related to bradycardia (HR

Purpose To evaluate the accuracy of central venous oxygen saturation recordings from a new in-line pediatric oximetry catheter. Design Prospective, observational study. Study population Eighteen pediatric patients who needed central venous access for monitoring and/or treatment between January 2006 and June 2006 in the pediatric intensive care unit of the Hospital for Sick Children in Toronto, Canada. Methods and main results Measurements were done at the baseline and then every 4-8 hrs. The monitor was calibrated in vivo at the baseline and then daily. In vitro calibration of the monitor was also performed in the last five patients. The hemoglobin value was updated when there was a significant change. The maximum duration of sampling was 72 hrs (if indicated). There were 131 measurements in 17 patients; each subject had a different number of paired measurements (median 5). Three patients were excluded due to violation of the protocol, and 113 measurements were left in analysis. The mean difference of catheter value from the laboratory value was -1.01 (median 0). The interquartile range was 5. The difference of both methods was evenly distributed as per a Bland-Altman plot, with one patient's data lying outside of the comparable limits of ± 1.96 sd from the mean differences. The relationship of the difference between the catheter data and the lab data to the independent variables (age, weight, gender, catheter tip, diagnosis, and signal quality index) was estimated by using the multiple regression analysis (version 9.1, SAS Institute, Cary, NC). All variables were eliminated. The Pearson correlation coefficient between lab-mixed venous oxygen saturation and oximetry catheter readings for measurements was 0.88. Conclusion In this limited number of patients, use of the PediaSat venous oximetry catheter was safe and had good agreement with co-oximetry-measured values.

IntroductionInduction of anesthesia in a child can often be arelaxed event, but this is not always the case. Theselection of approach and technique has some basisin scientific evidence and published data, but in real-ity the procedure is more complex. Induction ofanesthesia is not simply a technical exercise. Itinvolves a variety of rapid individual evaluations andjudgements relating to both child and parent, the sit-uation and to some extent the experience and prefer-ences of the individual anesthetic team on aparticular day.It is clear from the outset that one mode of induc-tion may be indicated over the other in particular clini-cal situations, but that in more general terms, it is nota case of one or the other. Most pediatric anesthetistsuse both induction methods at different times but usu-ally have a preference. The articles below thereforereflect the personal opinions of two experienced pediat-ric anesthetists who have kindly agreed to put a casefor each method. They have addressed the sciencewhere possible but also have given personalizedaccounts which will stimulate individual reflection onpractice and rationale.In support of intravenous induction of anesthesiaDr Marzena ZielinskaFor many children, the induction of anesthesia can behighly stressful and current estimations, indicate thatmore than 60% of children suffer anxiety in the pre-operative period (1). The reasons of this are complex:first, children are afraid of being separated from theirparents and home environment and this is com-pounded by unfamiliar routines, new strange people,frightening equipment such as anesthetic machine andsurgical instruments which all contribute to the processof building high levels of anxiety.Not surprisingly then, the method of induction canplay a crucial role in generation of perioperative anxi-ety. Pediatric anesthesiologists make a choice betweentwo recommended methods: inhalational or intra-venous. Traditionally, the inhalational method ofinduction of anesthesia is thought to be less harmfulfor children (2–4). In many textbooks of pediatricanesthesia, the potential fear of a needle among pediat-ric patients is stressed. But it is clear to experiencedanesthesiologists working with children that childrenare not only afraid of a needle but also a mask. Usu-ally, children struggle to accept the presence of anyforeign body on their face and they start to expresstheir dissatisfaction immediately after placing the maskclose to their face. This then becomes even less accept-able if the mask is then kept against their face despitetheir protests. Volatile agents have an unfamiliar andoften pungent smell causing even the most well-pre-pared child to lose composure when the concentrationof anesthetic gas is increased.

Summary More children die of congenital heart disease (CHD) in low-income countries and acquired cardiac disease is more frequent. Advances in diagnosis, surgery, perfusion and anesthesia in the developed world have had dramatic results on children’s lives, and many forms of CHD can now be safely corrected or palliated. However, in developing countries, for the children who receive cardiac surgery, perioperative mortality and morbidity remain high. Pediatric cardiac anesthesia is a specialty in its infancy worldwide, and in developing countries, it is often nonexistent. Visiting ‘specialists’ as part of medical mission teams often provides anesthesia, but the hope for the future is that local staff will be trained in pediatric cardiac anesthesia and collaborative regional cardiac centers will be the mainstay of care, offering safer surgery to more children.

ObjectivesWe hypothesised that sildenafil would improve hemodynamics in children with pulmonary hypertension and attenuate rebound pulmonary hypertension after inhaled nitric oxide withdrawal.Patients and methodsWe undertook an open-label, single-drug study of sildenafil in patients under 5 years of age with either symptomatic or rebound pulmonary hypertension following inhaled nitric oxide withdrawal.ResultsWe recruited 25 patients (median age 180 days, 10–1790) to receive sildenafil. The median right ventricular to systemic systolic blood pressure ratio before sildenafil therapy was 1.0 (0.5–1.4) and decreased to 0.5 (with a range from 0.3 to 1.3; p = 0.0002). In five patients the baseline pulmonary vascular resistance index was 10 (7.1–13.6) Wood units metre square and decreased to 5.8 (2.7–15.6) Wood units metre square (p = 0.04) at 6 months. Ten patients were treated with sildenafil for a median of 34 days (9–499) until resolution of pulmonary artery hypertension and continue to do well. Six patients continued sildenafil therapy for a median of 1002 days (384–1574) with improvement but without resolution of pulmonary hypertension. There was no change in serum creatinine, urea, liver function tests, or platelet count. In 15 patients sildenafil abolished rebound pulmonary artery hypertension following withdrawal of inhaled nitric oxide. Median right ventricular pressure to systemic systolic pressure ratio decreased from 1.0 (0.8–1.4) during nitric oxide withdrawal to 0.4 (0.3–0.8) p = 0.006 after pre-treatment with sildenafil.ConclusionIn children under 5 years of age with severe pulmonary hypertension, sildenafil therapy resulted in prolonged hemodynamic improvements without adverse effects. Sildenafil attenuated rebound pulmonary hypertension after withdrawal of inhaled nitric oxide.

Objective: To derive evidence-based recommendations regarding early extubation strategy after congenital cardiac surgery. Outcomes: Incidence of total mortality, morbidity, reintubation, length, and costs of intensive care unit and hospital stay. Evidence: Medline, Embase, and the Cochrane-controlled trial register on the Cochrane library were searched from the earliest achievable date of each database to present. No language restrictions were applied. Retrieved reprints were evaluated according to a priori inclusion criteria, and those included were critically appraised using established internal validity criteria. Benefits and Harms: Early extubation (in the operating room or ≤6 hours after surgery) was associated with a lower early mortality. There was a trend toward lower ICU and hospital length of stays, lower hospital costs, and less respiratory morbidity. There was no difference in the rate of reintubation in those extubated early versus late. Conclusion: Early extubation appears safe and is associated with reduction in length of ICU and hospital stay without adverse effects on mortality or morbidity. However, studies to date are poor, heterogeneous, and not suitable to determine a causal effect. Therefore, there is need for a well-designed randomized clinical trial to demonstrate the potential significant benefits of early extubation. (J Card Surg 2010;25:586-595)

Background Infants with esophageal atresia (EA), omphalocele, and anorectal malformation (ARM) often have associated congenital heart disease. Recognition of significant cardiac defects, which compromise patient well-being in the perioperative period, is essential before going to the operating room. However, urgent echocardiography may be unavailable, and surgery may therefore be delayed in some cases. We wished to determine if routine echocardiography is necessary for neonates with these diagnoses, or if appropriate patients could be selected. Methods Retrospective review of all infants admitted to the neonatal intensive care unit with EA, omphalocele, or ARM for 5 years (2003-2008). Clinically relevant findings in the cardiovascular examination (murmur, tachycardia, abnormal 4 limb blood pressure, cyanosis, shock), abnormalities in respiratory examination (intubation, tachypnea, desaturations), or abnormal chest x-ray (cardiomegaly, abnormal pulmonary vasculature) were documented. Cardiac defects were categorized according to their clinical impact as major or minor to differentiate those disorders which may influence timing of surgical intervention. Results Eighty-six infants were identified (33 EA, 21 omphalocele, 32 ARM). Thirty-seven (42.9%) patients had congenital heart disease on echocardiography evaluation, of which 11 (12.7%) were classified as major and 26 (30.2%) were minor. The sensitivity, specificity, positive predictive value, and negative predictive value of abnormal clinical and radiologic combined assessment for a major cardiac defect were 100% (95% confidence interval [CI], 0.76-1), 64% (95% CI, 0.61-0.64), 28% (95% CI, 0.22-0.29), and 100% (95% CI, 0.94-1.00), respectively. Conclusions Normal clinical and radiologic examination predicted absence of a significant cardiac abnormality on echocardiography in 100% of cases. We conclude that routine echocardiography before embarking on surgical intervention may not always be necessary but should be reserved for infants with abnormal clinical and/or radiologic findings.

ObjectivesThe purpose of our study was to characterize the hemodynamic and corresponding pharmacokinetic responses to a single dose of oral sildenafil by children with pulmonary arterial hypertension (PAH) undergoing invasive testing.BackgroundAlthough used frequently for the treatment of children with PAH, data regarding the acute responses to sildenafil are limited.MethodsThirty-six patients (mean age 7.5 ± 5.9 years; 24 females) were studied during cardiac catheterization with general anesthesia. Eight of 36 (22%) had idiopathic PAH; the remainder had associated congenital heart disease. Hemodynamics and serum cyclic-guanosine monophosphate levels (cGMP) were evaluated at baseline and after inhaled nitric oxide (NO) (40 ppm). In addition, cGMP and sildenafil levels were measured 30 min after administration of sildenafil (0.5 mg/kg, suspended in 5 ml sterile water) through a nasogastric tube.ResultsFor the 36 patients, the pulmonary vasodilating capability of oral sildenafil was lower than that of inhaled NO (2.8% vs. 11.6% reduction in pulmonary vascular resistance indexed to body surface area [PVRI], respectively; p = 0.01). However, only 21 of 36 (58%) patients had a detectable sildenafil level. In those with detectable sildenafil levels, the fall in PVRI was greater (−11.6% vs. −19.1%, p = NS). Mean cGMP levels at baseline and after NO were 41.8 ± 20.0 pmol/ml and 83.8 ± 35.5 pmol/ml, respectively (p < 0.0001). Surprisingly, there was no significant increase in cGMP in patients with either undetectable (37.5 ± 29.8 pmol/ml) or detectable (44.4 ± 31.7 pmol/ml) sildenafil levels (p = NS compared with baseline) with sildenafil.ConclusionsOur study demonstrates suboptimal absorption of sildenafil in almost half the children undergoing acute hemodynamic testing. When detectable, there was no statistically significant difference between the fall in PVRI associated with sildenafil and NO despite lower circulating cGMP levels in the sildenafil group. These data should be taken into account when designing acute testing protocols, and assessing the acute response to sildenafil in patients with PAH.

We present a 15-yr-old-girl who underwent interventional lung assist via Novalung (Novalung GmbH, Lotzenaecker, Heckingen, Germany) insertion as a bridge to bilateral lung transplantation for pulmonary veno-occlusive disease. This is the first pediatric and smallest patient to receive the device. Central cannulation was chosen to optimize blood flow through the device by enabling larger-sized cannulae in a patient with high pulmonary artery pressure. Novalung provided circulatory support with oxygenation obviating the need for extracorporeal membrane oxygenation while waiting for lung transplantation.

Hybrid strategies for single ventricle palliation may differ from Norwood strategies in terms of anatomic and physiologic growth stimuli to the pulmonary arteries (PA), hemodynamics, resource utilization, and survival. Few studies have directly compared these strategies.In all, 58 patients underwent Norwood (Blalock-Taussig shunt; n = 39) or hybrid (n = 19) single ventricle palliation (2004 to 2007). Hemodynamics, PA morphology, hemodynamics, resource utilization, and survival were reviewed.At pre-stage 2 evaluation, there were nonsignificant trends toward lower ventricular end-diastolic pressure, higher mixed venous saturation, and larger Nakata and lower lobe indices in the hybrids. Mean PA pressures were not different between groups. Four Norwood patients (10%) underwent transplantation before stage 2 palliation. Forty-two patients underwent stage 2 palliation (bidirectional cavopulmonary shunt or stage 2 hybrid (aortic arch reconstruction and bidirectional cavopulmonary shunt). Requirement for PA plasty, postoperative CVP, stage 2 survival, and 1-year survival were similar between groups. Combined (stage 1 plus stage 2) intubation time, intensive care unit time, and hospital length of stay was shorter for hybrids in comparison with Norwood survivors (p0.05). Comparison of resource utilization at the time of arch reconstruction (Norwood procedure or stage 2 hybrid), demonstrated a time-related trend toward improvement (weak negative correlation: intubation, rho = -0.386, p = 0.172; intensive care unit stay, rho = -0.487, p = 0.077; hospital stay, rho = -0.429, p = 0.126) in the hybrid group, but not in the Norwood group.Hybrid palliation does not have a significant adverse impact on PA development, with comparable PA growth and hemodynamics. The demonstration of equivalent survival, diminished hospital utilization, and trends indicating ongoing refinement of the hybrid strategy warrants a prospective randomized trial.

Objective This study compared the effects of reconstituted fresh whole blood against standard blood component therapy in neonates undergoing cardiac surgery. Methods Patients less than 1 month of age were randomized to receive either reconstituted fresh whole blood (n = 31) or standard blood component therapy (n = 33) to prime the bypass circuit and for transfusion during the 24 hours after cardiopulmonary bypass. Primary outcome was chest tube drainage; secondary outcomes included transfusion needs, inotrope score, ventilation time, and hospital length of stay. Results Patients who received reconstituted fresh whole blood had significantly less postoperative chest tube volume loss per kilogram of body weight (7.7 mL/kg vs 11.8 mL/kg; P = .03). Standard blood component therapy was associated with higher inotropic score (6.6 vs 3.3; P = .002), longer ventilation times (164 hours vs 119 hours; P = .04), as well as longer hospital stays (18 days vs 12 days; P = .006) than patients receiving reconstituted fresh whole blood. Of the different factors associated with the use of reconstituted fresh whole blood, lower platelet counts at 10 minutes and at the end of cardiopulmonary bypass, older age of cells used in the prime and throughout bypass, and exposures to higher number of allogeneic donors were found to be independent predictors of poor clinical outcomes. Conclusions Reconstituted fresh whole blood used for the prime, throughout cardiopulmonary bypass, and for all transfusion requirements within the first 24 hours postoperatively results in reduced chest tube volume loss and improved clinical outcomes in neonatal patients undergoing cardiac surgery.

ObjectiveCarbon dioxide is suggested to increase oxygen delivery after the Norwood procedure. We sought to quantitatively define the effects of stepwise increases in arterial carbon dioxide tension on systemic oxygen transport and cerebral and splanchnic circulation after the Norwood procedure.MethodsSeven sedated, paralyzed, and mechanically ventilated neonates were studied after the Norwood procedure. Arterial carbon dioxide tension increased from 40-50-60 mm Hg using inspired carbon dioxide. Each step was 30 minutes. Pulmonary and systemic blood flow, vascular resistance, and oxygen delivery were calculated with the measurement of oxygen consumption and blood gases and pressures from the aorta, superior vena cava, and pulmonary vein. Plasma epinephrine and norepinephrine were measured. Cerebral and splanchnic oxygen saturations were measured by near-infrared spectroscopy, and cerebral blood flow velocity was measured by transcranial Doppler.ResultsStepwise increase in arterial carbon dioxide tension was associated with a decrease in systemic vascular resistance (P < .001) and an increase in systemic blood flow (P < .01) and oxygen delivery (P < .0001), but not with significant changes in total pulmonary vascular resistance and pulmonary blood flow. Cerebral oxygen saturation increased (P < .0001), and splanchnic oxygen saturation decreased (P < .01). Oxygen consumption decreased (P < .01), and epinephrine and norepinephrine increased (P < .01 and .05).ConclusionModerate hypercapnia increases systemic blood flow because of its effect on systemic vascular resistance after the Norwood procedure. The increase in systemic blood flow is primarily a consequence of increased cerebral blood flow that compromises splanchnic circulation. The decrease in oxygen consumption improves oxygen transport, but the increase in catecholamines may be undesirable. Clinical use of carbon dioxide aiming to improve oxygen delivery should be with caution.

Background The comprehensive Aristotle score has been proposed as an individualized measure of the complexity of a given surgical procedure and has been reported to significantly correlate with postoperative morbidity and mortality after the Norwood procedure. An important factor leading to postoperative morbidity and mortality is low cardiac output. We studied the correlation between the comprehensive Aristotle score and cardiac output (CO) in infants after the Norwood procedure. Methods and Results Respiratory mass spectrometry was used to continuously measure systemic oxygen consumption (VO 2 ) in 22 infants for 72 hours postoperatively. Arterial, superior vena caval and pulmonary venous blood gases were measured at 2 to 4 hour intervals to calculate CO. The comprehensive Aristotle score was collected. Hospital mortality was 4.5%. The comprehensive Aristotle score ranged from 14.5 to 23.5 and negatively correlated with CO ( P = 0.027). Among the patient-adjusted factors, myocardial dysfunction (n = 10), mechanical ventilation to treat cardiorespiratory failure (n = 9) and atrioventricular valve regurgitation (n = 4) ( P = 0.01) negatively correlated with CO ( P = 0.06 to 0.07). Aortic atresia (n = 9) was associated with a lower CO ( P = 0.01) for the first 24 hours which linearly increased overtime ( P = 0.0001). No correlation was found between CO and other factors ( P > 0.3 for all). Conclusions Comprehensive Aristotle score significantly negatively correlates with CO after the Norwood procedure. A preoperative estimation of the comprehensive Aristotle score, particularly in association with myocardial dysfunction, mechanical ventilation to treat cardiorespiratory failure, atrioventricular valve regurgitation and aortic atresia may help to anticipate a high postoperative morbidity with low cardiac output syndrome.

OBJECTIVES Cardiopulmonary bypass in infants results in a hypermetabolic response. Energy requirements of these patients have not been well studied. We assessed energy expenditure and caloric and protein intake during the first 3 days following the Norwood procedure. DESIGN Clinical investigation. SETTING Children's hospital. PATIENTS Seventeen infants (15 boys, age 4-92 days, median 7 days). INTERVENTIONS VO2 and VCO2 were continuously measured using respiratory mass spectrometry in 17 infants for the first 72 hrs following the Norwood procedure. The respiratory quotient was determined as VCO2/VO2. Energy expenditure was calculated using the modified Weir equation. Measurements were collected at 2- to 4-hr intervals. The mean values in the first 8 hrs, hours 8-32, hours 32-56, and the last 16 hrs were used as representative values for postoperative days 0, 1, 2, and 3. Total caloric and protein intakes were recorded for each day. MEASUREMENTS AND MAIN RESULTS Energy expenditure, VO2, and VCO2 were initially high; declined rapidly during the first 8 hrs; and were maintained relatively stable in the following hours (p < .0001). Respiratory quotient showed a significant linear increase over the 72 hrs (p = .002). Energy expenditure on days 0, 1, 2, and 3 was 43 +/- 11, 39 +/- 8, 39 +/- 8, and 41 +/- 6 kcal/kg/day, respectively. Total caloric intake was 3 +/- 1, 14 +/- 5, 31 +/- 16, and 51 +/- 16 kcal/kg/day. Protein intake was 0, 0.2 +/- 0.2, 0.6 +/- 0.5, and 0.9 +/- 0.5 g/kg/day on days 0, 1, 2, and 3, respectively. CONCLUSIONS Infants exhibit a hypermetabolic response immediately following the Norwood procedure. Caloric and protein intake was inadequate to meet energy expenditure during the first 2 days after surgery. Further studies are warranted to examine the effects of caloric and protein supplementation on postoperative outcomes in infants after cardiopulmonary bypass.

Antithrombin is one of the main natural coagulation system inhibitors. It is potentiated by heparin, and may be a key component of heparin response, particularly in infants aged1 year. We sought to determine the impact of baseline antithrombin activity on response to heparin and thrombin generation during cardiopulmonary bypass (CPB).Secondary analysis was performed using linear regression analyses, which combined patients from a trial of individualized versus weight-based heparin management for 90 infants aged1 year undergoing cardiac surgery.Mean baseline antithrombin activity was 0.69 ± 0.16 U/mL, and it was lower in neonates than in older infants (0.57 ± 0.15 vs 0.77 ± 0.12 U/mL; P.001). Lower baseline antithrombin activity was associated with lower postheparin anti-Xa activity (EST [SE]: +0.47 (0.19) U/mL per 100 U/kg heparin; P = .01) and higher heparin doses during surgery (EST [SE]: +51 (17) U/kg per hour; P = .003). The administration of fresh frozen plasma attenuated the effect of low baseline antithrombin activity (interaction P value = .009). Patients with lower anti-Xa activity recorded during CPB had higher levels of thrombin-antithrombin complex (EST [SE]: +12.8 (4.7) ng/mL per -1 U/mL anti-Xa; P = .006); prothrombin activation fragment 1.2 (EST [SE]: +0.13 (0.07) log pg/mL per -1 U/mL anti-Xa; P = .06); and D-dimer (EST [SE]: -0.25 (0.09) log ng/mL per -1 U/mL anti-Xa; P = .009) in the postoperative period after adjustment for baseline antithrombin activity, duration of CPB, amount of fresh frozen plasma and heparin used throughout surgery in multivariable models.Low circulating antithrombin activity is associated with lower heparin efficacy, which ultimately leads to a lower ability to suppress thrombin generation during CPB. Determination of risk factors for heparin resistance, and potentially, antithrombin replacement therapy, may individualize and improve anticoagulation treatment.

ObjectivesThe purpose of this study was to evaluate the effects of dopamine on hemodynamic status and oxygen transport in neonates after the Norwood procedure.BackgroundDopamine is widely used to augment cardiac performance and increase oxygen delivery (Do2) in patients after cardiopulmonary bypass (CPB). This might be at the expense of increased myocardial and systemic oxygen consumption (Vo2), thus offsetting the improved Do2. This balance is particularly fragile in critically ill neonates.MethodsSystemic oxygen consumption was continuously measured with respiratory mass spectrometry in 13 sedated, paralyzed, and mechanically ventilated neonates for 72 h after the Norwood procedure. Arterial, superior vena caval, and pulmonary venous blood gases were measured to calculate pulmonary blood flow (Qp) and systemic blood flow (Qs), Do2, and oxygen extraction ratio (ERo2). Rate-pressure product was calculated. Dopamine at a dose of 5 μg/kg/min was routinely administered at cessation of CPB and terminated within the first 48 h. Hemodynamic and oxygen transport measures were obtained before and at 100 min after the termination of dopamine.ResultsTerminating dopamine was not associated with significant changes in arterial pressure, Qp, Qs, or Do2but was associated with a significant decrease in heart rate (p = 0.003), rate-pressure product (p = 0.03), and Vo2(−20 ± 11%, p < 0.0001), resulting in a significant decrease in ERo2(p = 0.01).ConclusionsDopamine induces a significant increase in Vo2in neonates after the Norwood procedure, and termination is associated with an improved balance of Vo2–Do2. These data further emphasize the importance of understanding changes in Vo2as well as Do2in infants after cardiac surgery.

OBJECTIVES: We conducted a randomized controlled trial of the effects of remote ischemic preconditioning (RIPC) in children undergoing repair of congenital heart defects. BACKGROUND: Remote ischemic preconditioning reduces injury caused by ischemia-reperfusion in distant organs. Cardiopulmonary bypass (CPB) is associated with multi-system injury. We hypothesized that RIPC would modulate injury induced by CPB. METHODS: Children undergoing repair of congenital heart defects were randomized to RIPC or control treatment. Remote ischemic preconditioning was induced by four 5-min cycles of lower limb ischemia and reperfusion using a blood pressure cuff. Measurements of lung mechanics, cytokines, and troponin I were made pre- and postoperatively. RESULTS: Thirty-seven patients were studied. There were 20 control patients and 17 patients in the RIPC group. The mean age and weight of the RIPC and control patients were not different (0.9 +/- 0.9 years vs. 2.2 +/- 3.4 years, p = 0.4; and 6.9 +/- 2.9 kg vs. 11.5 +/- 10 kg, p = 0.06). Bypass and cross-clamp times were not different (80 +/- 24 min vs. 88 +/- 25 min, p = 0.3; and 55 +/- 13 min vs. 59 +/- 13 min, p = 0.4). Levels of troponin I postoperatively were greater in the control patients compared with the RIPC group (p = 0.04), indicating greater myocardial injury in control patients. Postoperative inotropic requirement was greater in the control patients compared with RIPC patients at both 3 and 6 h (7.9 +/- 4.7 vs. 10.9 +/- 3.2, p = 0.04; and 7.3 +/- 4.9 vs. 10.8 +/- 3.9, p = 0.03, respectively). The RIPC group had significantly lower airway resistance at 6 h postoperatively (p = 0.009). CONCLUSIONS: This study demonstrates the myocardial protective effects of RIPC using a simple noninvasive technique of four 5-min cycles of lower limb ischemia and reperfusion. These novel data support the need for a larger study of RIPC in patients undergoing cardiac surgery.

ObjectiveManagement strategy for the postoperative Norwood neonate has been formulated from models that have estimated oxygen consumption (vo2). Superior vena caval oxygen saturation (Svo2), systemic arterial and superior vena caval oxygen saturation difference (Sa-vo2), and oxygen excess factor (Ω = arterial oxygen saturation/Sa-vo2) have been used as indirect indicators to estimate systemic blood flow (Qs) and oxygen delivery (Do2). We sought to examine the correlation of the indirect indicators to vo2-derived measures of oxygen transport.MethodsRespiratory mass spectrometry was used to continuously measure vo2 after the Norwood procedure (n = 13). Measured saturations and the direct Fick equation were used to obtain pulmonary blood flow, Qs, DO2, and oxygen extraction ratio (ERo2) values. Correlations to Svo2, Sa-vo2, and Ω were sought.ResultsThere was a close correlation of Svo2, Sa-vo2, and Ω to ERo2 (r = 0.92, 0.96, and 0.97, respectively; P < .0001). Correlation to Qs and Do2 was variable (r = 0.39 to 0.78, respectively; P < .0001). Correlation to vo2 was poor but significant (r = 0.24 to 0.40, P < .0001). Inclusion of vo2 improved the correlation to Qs and Do2 (r = 0.66 to 0.97, P < .0001).ConclusionsThe close correlation of Svo2, Sa-vo2, and Ω to ERo2 indicates that each is a measure of the balance of Do2 and extraction. The significant but less reliable correlation to Do2 and vo2 indicates the values for Svo2, Sa-vo2, and Ω do not discriminate between the contribution of Do2 and vo2. Measured vo2 and hemodynamics may improve the optimization of postoperative management strategy in the individual neonate.

Background— Pulmonary arterial hypertension (PAH) is a progressive and fatal disease. Sildenafil is a type 5 phosphodiesterase inhibitor and pulmonary vasodilator. Therefore, we hypothesized that sildenafil would improve distance walked in 6 minutes and hemodynamics in children with PAH. Methods and Results— After baseline assessment of hemodynamics by cardiac catheterization and distance walked in 6 minutes, we administered oral sildenafil at 0.25 to 1 mg/kg 4 times daily to 14 children (median age, 9.8 years; range, 5.3 to 18). Diagnoses were primary (n=4) and secondary (n=10) PAH. We repeated the 6-minute walk test at 6 weeks and at 3, 6, and 12 months (n=14) and cardiac catheterization (n=9) after a median follow-up of 10.8 months (range, 6 to 15.3). During sildenafil therapy, the mean distance walked in 6 minutes increased from 278±114 to 443±107 m over 6 months ( P =0.02), and at 12 months, the distance walked was 432±156 m ( P =0.005). A plateau was reached between 6 and 12 months ( P =0.48). Mean pulmonary artery pressure decreased from a median of 60 mm Hg (range, 50 to 105) to 50 mm Hg (range, 38 to 84) mm Hg ( P =0.014). Median pulmonary vascular resistance decreased from 15 Wood units m 2 (range, 9 to 42) to 12 Wood Units m 2 (range, 5 to 29) ( P =0.024). Conclusions— Oral sildenafil has the potential to improve hemodynamics and exercise capacity for up to 12 months in children with PAH. Confirmation of these results in a randomized, controlled trial is essential.

Introduction: Heparin-based anticoagulation in children is challenging as they have a high prevalence of heparin resistance. Antithrombin, one of the main natural anticoagulant inhibitors that potentiate heparin anticoagulation activity, might be a critical component of heparin response and anticoagulation effectiveness. Objectives: Determine the impact of antithrombin levels on anticoagulation (heparin sensitivity and effectiveness) during cardiopulmonary bypass (CPB) in children Methods: Secondary analysis of a randomized controlled trial of individualized vs weight based heparin management in 90 infants Results: As expected, older patients had higher blood antithrombin levels (relative increase of 16±6% for patients >6 months old vs. those Conclusions: Low antithrombin level is associated with resistance to heparin and decreased anticoagulation activity, ultimately leading to lower ability to suppress thrombin generation during CPB. Antithrombin supplementation may potentially individualize and improve anticoagulation.

Background Remote ischemic preconditioning ( RIPC ) harnesses an innate defensive mechanism that protects against inflammatory activation and ischemia‐reperfusion injury, known sequelae of cardiac surgery with cardiopulmonary bypass. We sought to determine the impact of RIPC on clinical outcomes and physiological markers related to ischemia‐reperfusion injury and inflammatory activation after cardiac surgery in children. Methods and Results Overall, 299 children (aged neonate to 17 years) were randomized to receive an RIPC stimulus (inflation of a blood pressure cuff on the left thigh to 15 mm Hg above systolic for four 5‐minute intervals) versus a blinded sham stimulus during induction with a standardized anesthesia protocol. Primary outcome was duration of postoperative hospital stay, with serial clinical and laboratory measurements for the first 48 postoperative hours and clinical follow‐up to discharge. There were no significant baseline differences between RIPC (n=148) and sham (n=151). There were no in‐hospital deaths. No significant difference in length of postoperative hospital stay was noted ( sham 5.4 versus RIPC 5.6 days; difference +0.2; adjusted P =0.91), with the 95% confidence interval (−0.7 to +0.9) excluding a prespecified minimal clinically significant differences of 1 or 1.5 days. There were few significant differences in other clinical outcomes or values at time points or trends in physiological markers. Benefit was not observed in specific subgroups when explored through interactions with categories of age, sex, surgery type, Aristotle score, or first versus second half of recruitment. Adverse events were similar ( sham 5%, RIPC 6%; P =0.68). Conclusions RIPC is not associated with important improvements in clinical outcomes and physiological markers after cardiac surgery in children. Clinical Trial Registration URL : clinicaltrials.gov. Unique identifier: NCT 00650507.

There has been a paradigm shift toward “fast-track” management with early extubation (EE) in cardiac surgery. Our retrospective, matched case-control study wishes to define the benefits of EE in pediatric congenital heart surgery. We examined 50 consecutive pediatric cardiac surgery patients extubated in the operating room (February 2009 to July 2009) against a control group of delayed-extubation patients. No significant differences were found in preoperative variables except heart failure medication. Significant intraoperative variables included the following: blood products (363 vs 487 mL, P = .023), morphine (62% vs 6%, P < .0001), and inotropes (16% vs 60%, P < .0001) given. Postoperatively significant differences included hospital stay and lower inotrope scores in the early-extubation group (14.89 vs 31.68, P < .0001). The reintubation rate was not significant. EE patients have equivalent hemodynamic profiles shown by a decreased necessity for inotropic support. We conclude that EE is feasible in low-/medium-risk pediatric congenital heart surgery patients.

Background It is unclear if children after heart transplantation (HTX) are at risk for developing increased myocardial fibrosis. Diffuse myocardial fibrosis can be estimated by myocardial longitudinal relaxation (T1) times. Methods Twenty cardiovascular magnetic resonance (CMR) studies in 17 patients after HTX (mean age 13.2 years, range 1.2 17.4 years, 9 female) were analysed retrospectively and compared to CMR studies in nine healthy controls

Background: After institutional approval and parental consent, 103 children, aged 6 months to 18 years, who were undergoing repair of simple and complex congenital heart lesions using cardiopulmonary bypass (CPB) were studied and compared with a group of 135 children who had undergone similar surgery in our institution in the year before. Methods: Anaesthesia for study patients included fentanyl (

We report a case of obstructed total anomalous pulmonary venous drainage that was repaired using the sutureless repair with the in situ pericardium. In the immediate postoperative period, the patient developed massive air embolism that was managed by mechanical support. The patient recovered without any significant clinical sequelae.

Background Cerebral hyperthermia after hypothermic cardiopulmonary bypass has been poorly documented for adults and never in children. This study was designed to monitor brain temperature during and up to 6 h after cardiopulmonary bypass in infants and children. Methods Fifteen infants and children, between 3 months and 6 yr of age, were studied. A right retrograde jugular bulb catheter was used to measure the jugular venous bulb temperature (JVBT) during the procedure and the first 6 h in the critical care unit. The temperature of the blood from the bypass machine was measured at the aorta through the cannula using an indwelling temperature probe. All data were acquired every minute. Results The age of the patients ranged from 3 to 71 months (median, 15 months). The mean weight was 11.5 +/- 8.4 kg. The mean JVBT recorded at the end of cardiopulmonary bypass was 36.9 +/- 1.4 degrees C but reached 39.6 +/- 0.8 degrees C after six h (P < 0.01). The kinetics of brain rewarming was determined by the slope of the mean JVBT and corresponded to y +/- 0.006x + 37.21 (r2 = 0.97). The JVBT differed from the tympanic temperature after 200 min (P < 0.01) and the lower esophageal (P < 0.05) and rectal (P < 0.001) temperatures after 300 min. After 6 h, the tympanic, rectal, and lower esophageal temperatures were 37.8 +/- 0.9, 37.7 +/- 0.6, and 38.4 +/- 0.7 degrees C, respectively, whereas the JVBT was 39.6 +/- 0.8 degrees C (P < 0.001). However, the correlation coefficients between the JVBT and the tympanic, rectal, and esophageal temperatures were 0.98, 0. 85, and 0.97, respectively. No complications were recorded with placement of the jugular bulb catheter. Conclusions Mean JVBT was significantly increased over the mean core temperature at all times from rewarming by cardiopulmonary bypass onward. Although the lower esophageal, rectal, and tympanic temperatures correlated well with JVBT, all three failed to reflect JVBT during recovery. This observation might help to elucidate factors involved in the functional and structural neurologic injury known to occur in pediatric patients.

The improvements in care of children with heart disease have resulted in a major decrease in mortality and increased attention to adverse events and quality of survival. There is important neurological morbidity in children with congenital heart disease. Some problems such as stroke or seizure may be immediately apparent, but others, such as learning disability and motor delay emerge over time. The etiology is multifactorial and includes genetic, procedural and social causes. Only some factors are modifiable. Over the last decade, evidence has been presented that anesthetic drugs may be a potential cause of CNS morbidity. Neonates and infants may be particularly vulnerable to this. The purpose of this article is to describe the multiple known causes of neurodevelopmental impairment in children with heart disease, including anesthetic agents, and to explore the relationship between congenital heart disease and its treatment in this regard.

It is thought that patients with cardiomyopathy have an increased risk of cardiac arrest on induction of anesthesia, but there is little available data. The purpose of this study was to identify the incidence and potential risk factors for cardiac arrest upon induction of anesthesia in children with cardiomyopathy in our institution.A retrospective chart review was performed. Eligible patients included patients admitted between 1998 and 2008 with the International Statistical Classification of Disease code for cardiomyopathy (ICD-9 code 425) who underwent airway intervention for sedation or general anesthesia in the operating room, cardiac diagnostic and interventional unit (CDIU) or intensive care unit. Patients undergoing emergency airway intervention following cardiovascular collapse were excluded. For each patient, we recorded patient demographics, disease severity, anesthesia location, and anesthetic technique.One hundred and twenty-nine patients with cardiomyopathy underwent a total of 236 anesthetic events, and four cardiac arrests were identified. One was related to bradycardia (HR60), two were attributed to bradycardia in association with severe hypotension (systolic blood pressure45), and the fourth arrest was related to isolated severe hypotension. Two occurred in the operating suite and two in the CDIU. There was no resulting mortality. One patient progressed to heart transplantation. Multiple combinations of anesthetic drugs were used for induction of anesthesia.We performed a review of the last 10 years of anesthesia events in children with cardiomyopathy. We report four cardiac arrests in two patients and 236 anesthetic events (1.7%). To the best of our knowledge, this is the largest review of these patients to date but is limited by its retrospective nature. The low cardiac arrest incidence prevents the identification of risk factors and the development of a cardiac arrest risk predictive clinical tool.

Background The bidirectional cavopulmonary connection (BCPC) is used in the staged palliation of univentricular hearts and places the cerebral and pulmonary vascular beds in series. Angiotensin-converting enzyme inhibitors (ACEI) are often used in this complex circulation, but the effects of their vasodilation are unclear. Objective Assessment of the acute response of perfusion pressure, flow and resistance across the systemic, cerebral and pulmonary vascular beds to ACEI in patients with a BCPC. Design Prospective interventional study. Setting Single tertiary care centre. Patients 12 patients with a BCPC (median age 28 months, weight 11.8 kg) undergoing a pre-Fontan catheterisation with MRI measurement of flows. Intervention Intravenous enalaprilat 0.005 or 0.01 mg/kg. Results Enalaprilat increased descending aorta flow (median 21.6%, p=0.0005), decreased total pulmonary vein flow (median 10.6%, p=0.025), and both superior caval vein flow (median 8.6%, p=0.065) and aortopulmonary collateral flow (median 15.5%, p=0.077) tended to decrease. Total cardiac output was unchanged (p=0.57). Systemic vascular resistance (median 41.9%, p=0.0005) and cerebral vascular resistance (median 23.4%, p=0.0005) decreased, but pulmonary vascular resistance (p=0.73) showed little change. There was evidence of autoregulation of cerebral blood flow. The proportion of descending aortic flow to total cardiac output increased (median 27 to 35%, p=0.001). Systemic oxygen saturation decreased from 87% to 83% (p=0.02). Conclusion Enalaprilat did not increase total cardiac output but redistributed flow to the lower body, with a concomitant decrease in arterial oxygen saturation. It is difficult to increase cardiac output in patients with a BCPC and ACEI should be used with caution in those with borderline aortic saturations.

More children die of congenital heart disease (CHD) in low-income countries and acquired cardiac disease is more frequent. Advances in diagnosis, surgery, perfusion and anesthesia in the developed world have had dramatic results on children's lives, and many forms of CHD can now be safely corrected or palliated. However, in developing countries, for the children who receive cardiac surgery, perioperative mortality and morbidity remain high. Pediatric cardiac anesthesia is a specialty in its infancy worldwide, and in developing countries, it is often nonexistent. Visiting 'specialists' as part of medical mission teams often provides anesthesia, but the hope for the future is that local staff will be trained in pediatric cardiac anesthesia and collaborative regional cardiac centers will be the mainstay of care, offering safer surgery to more children.

Corticosteroids are commonly administered perioperatively in pediatric cardiac surgery to reduce cardiopulmonary bypass induced inflammation. However, their effects on outcomes and potential for adverse events are not well defined.A review was undertaken of cardiac operations between September 2004 and December 2007 carrying a comprehensive Aristotle score 10 or greater. A nonrandomized comparison was undertaken comparing those patients having received intraoperative methylprednisolone at anesthesia induction or in the bypass circuit prime with those who did not. To account for nonrandom assignment of steroid use, a propensity model was created to establish each patient's probability of having received steroids (∼150 variables evaluated, 17 in final model, c-stat 0.94, p0.001). Associations between postoperative outcomes and intraoperative steroid use were modeled in multivariable linear regression models adjusted for propensity score and relevant surgical characteristics.In 221 identified cases, 134 (61%) patients received intraoperative steroids; of these, 44 (33%) also received preoperative doses. In propensity-adjusted regression models, intraoperative steroid use was associated with lower chest tube volume loss in the first 24 postoperative hours (-5.3 mL/kg, p0.001), and shorter durations of stay in intensive care (-2.3 days, p0.001) and hospital (-4.1 days, p0.001). Use of an additional preoperative dose resulted in further improvements, especially a reduction in duration of mechanical ventilation (-1.7 days versus no steroids, -1.2 days versus intraoperative steroids only, p = 0.002). Steroids were not associated with increased postoperative lactate, creatinine, or glucose levels, or odds of infection.Intraoperative steroid use is associated with improved postoperative outcomes for children undergoing high-risk cardiac surgery, with further benefits associated with a preoperative dose.

Objective: Aortic atresia (AA) is a risk factor for mortality after the Norwood procedure. The mechanisms remain unknown. We compared the profiles of systemic, cerebral, and splanchnic oxygen transport in neonates with hypoplastic left-heart syndrome with AA or aortic stenosis (AS) after the Norwood procedure. Methods: Systemic oxygen consumption (VO2) was measured using respiratory mass spectrometry for 72 h in 17 neonates(nineinthe AAgroup,eightintheASgroup).Cardiacoutput(CO),systemicvascularresistance (SVR),oxygendelivery(DO2),and oxygen extraction ratio (ERO2) were calculated combining with blood gases and pressures at 2—4-h intervals. Cerebral (ScO2) and splanchnic (SsO2) oxygen saturations were measured by near-infrared spectroscopy. The doses of dopamine, milrinone, phenoxybenzamine, and vasopressin were recorded. Preoperative echocardiographic left-ventricular morphology and ejection fraction ratio were measured. Results: Compared with the AS group,the AA grouphad lower CO (p = 0.03), higher SVR(p = 0.002), lowerDO2 (p = 0.07), VO2 (p = 0.003), and ScO2 (p = 0.07) duringthe first 40 h. SsO2 was insignificantly lower. Despite a similar ERO2, the AA group had higher lactate (p = 0.01). The AA group received higher doses of milrinone (p < 0.0001), vasopressin (p = 0.005), and phenoxybenzamine (p = 0.02), and lower higher doses of dopamine (p = 0.07). Vasopressin adversely correlated with systemic oxygen-transport variables and SsO2 (p < 0.05). The AA group had thicker left-ventricular posterior wall (p = 0.05) that was negatively correlated with CO (p = 0.02). Conclusions: AA is associated with an inferior status of systemic, cerebral, and splanchnic oxygen transport after the Norwood procedure. Aggressive use of vasopressin may worsen systemic oxygen transport and decrease splanchnic perfusion. # 2010 European Association for Cardio-Thoracic Surgery. Published by Elsevier B.V. All rights reserved.

Aortic atresia (AA) has been identified as a risk factor for mortality after the Norwood procedure. We compared postoperative systemic and regional (cerebral and splanchnic) oxygen transport profiles in neonates with hypoplastic left heart syndrome with or without AA after the Norwood procedure. Systemic oxygen consumption (VO 2 ) was measured using respiratory mass spectrometry postoperatively for 72 hrs in 17 neonates (n=9 in AA group and 8 in non-AA group). Arterial, superior vena cava, and pulmonary venous blood gases and pressures were measured at 2– 4 hr intervals to calculate cardiac output (CO), systemic vascular resistance (SVR), oxygen delivery (DO 2 ) and oxygen extraction ratio (ERO 2 ). Cerebral (ScO 2 ) and splanchnic (SsO 2 ) oxygen saturations were measured using near infrared spectroscopy. The doses of dopamine, vasopressin (up to 0.0008 unit/kg/min), phenoxybenzamine and milrinone were noted. When compared to non-AA group, AA group had lower CO (p=0.03), higher systolic arterial blood pressure (p=0.01) and SVR (p=0.002), lower DO 2 (p=0.07), VO 2 (p=0.003) and ScO 2 during the first 30 to 40 hrs. There was no significant difference in SsO 2 (p=0.12, n=7 in AA group and 3 in non-AA group). Despite a similar ERO 2 (p=0.5), AA group had higher lactate over 72 hrs (p=0.01). AA group received higher doses of vasopressin (p=0.005) and milrinone (p2 negatively correlated with vasopressin (p=0.05), positively correlated with milrinone (p=0.03) and dopamine (p2 that positively correlated with dopamine, but not with other drugs. Aortic atresia is associated with an inferior status of systemic, cerebral and splanchnic oxygen transport in neonates after the Norwood procedure. Aggressive use of vasopressin worsens systemic and splanchnic oxygen transport status. Postoperative management strategies should be directed to improve both systemic and regional oxygen transport in this special group of patients.

We appreciate the contribution of Dr Schranz and colleagues to the development of the hybrid procedure for single ventricle palliation and their insightful comments regarding our recent article.1 The hybrid procedure with bilateral pulmonary banding and arterial duct stenting was designed as a minimally invasive alternative to a Norwood procedure. By avoiding cardiopulmonary bypass and the consequent ischemia-reperfusion injury and systemic inflammatory response, we hypothesized that we would find minimally altered systemic hemodynamic and oxygen transport status as compared with the well-documented hemodynamic derangements associated with the Norwood procedure.2 We evaluated the hybrid strategy through analysis of dispassionate and objective data and, to our knowledge, our study represents the only published hemodynamic assessment of this strategy. As noted in our article, the patterns of hemodynamic alterations after hybrid procedures were more complex than might have been anticipated. Although the data are precise, Dr Schranz and colleagues appear to be concerned that these data may not accurately represent all hybrid procedures. Our intuition (without data) would suggest that this may be so and, consequently, we will endeavor to obtain another dataset in the future to determine whether the early position of this cohort on our learning curve was an important modulator of …

Background— After the Norwood procedure, early postoperative neonatal physiology is characterized by hemodynamic instability and imbalance of oxygen transport that is commonly attributed to surgical myocardial injury and a systemic inflammatory response to cardiopulmonary bypass (CPB). Because the Hybrid procedure (arterial duct stenting and bilateral pulmonary artery banding) avoids CPB, cardioplegic arrest, and circulatory arrest, we hypothesized that the Hybrid procedure is associated with superior postoperative hemodynamics and oxygen transport. Methods and Results— Oxygen consumption (VO 2 ) was continuously measured using respiratory mass spectrometry for 72 hours after Hybrid (n=6) and Norwood (n=13) procedures. Arterial, superior vena cava, and pulmonary venous blood gases and pressures were measured at 2- to 4-hour intervals to calculate systemic and pulmonary blood flows (Qs, Qp), and systemic vascular resistance (SVR), total pulmonary vascular resistance including pulmonary arterial band or B-T shunt (tPVR), cardiac output (CO), oxygen delivery (DO 2 ), and oxygen extraction ratio (ERO 2 ). Rate-pressure product was calculated as heart rate×systolic arterial pressure. When compared with the Norwood procedure, the early postoperative Hybrid patients had lower CO, higher SVR, and higher Qp:Qs ratios. In addition, the DO 2 and VO 2 were both lower in the Hybrids with higher ERO 2 and lactate levels. This early postoperative pattern reversed after 48 hours. Conclusions— Although Hybrid procedure avoids CPB and cardioplegic arrest, the early hemodynamic profile is not superior to the Norwood in terms of cardiac output and control of pulmonary blood flow. These data strongly suggest that a “hands off” approach to postoperative care in Hybrid patients may not be appropriate in patients with preoperative diminished myocardial function; and in such patients a Norwood-derived management strategy (afterload reduction and inotropic support) should be considered.

Congenital tracheal stenosis (CTS) is an uncommon condition that has challenged pediatric surgeons for decades. Patients with CTS can present with a wide spectrum of symptoms and varying degrees of severity. In addition, a variety of techniques have been devised to repair this malformation. A review of these procedures and our suggestions for clinical standards and practice guidelines will be presented in this paper. A retrospective review of the literature on CTS from 1964 to 31 March, 2006. There is not one standard technique for the repair of CTS, as individualized approach to each patient and airway lesion is necessary to optimize patient management; nevertheless there is a consensus about segmental resection and anastomosis being best for short segment stenosis while slide tracheoplasty is most effective for the long-segment ones. Conservative management is also an option for select group of patients with careful and close follow up. Survival following surgery over the years has improved, but mortality remained high, particularly in a specific subset of patients presenting at the age less than 1 month with associated cardiac malformations. In conclusion, CTS remains a significant challenge for pediatric surgeons. Additional research is required to improve our understanding of the pathogenesis of CTS, and to develop evidence-based treatment protocols for the entire spectrum of presentation including conservative management.