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Pulmonary artery sling is a rare childhood vascualr ring that is frequently associated with tracheal stensois. Consequently, neonates may present with a crictal airway obstruction if tehre is long segemt tarcheal stensosi and complete rings. Rapid diagnosis of this cardiac vascular malfomation and extent airway involvement is essentail as longterm outcoem can be excellent follwoing surgicla repair. In this review we focus on airway invetsigation and management for this challenging congential condition.

Neonatal pulmonary hypertension (PH) is associated with many severe congenital abnormalities (congenital diaphragmatic hernia) or acquired cardiorespiratory diseases such as pneumonia, meconium aspiration and bronchopulmonary dysplasia (BPD). If no cause is found it may be labelled idiopathic persistent pulmonary hypertension of the newborn. Although PH may result in life threatening hypoxia and circulatory failure, in the majority of cases, it resolves in the neonatal period following treatment of the underlying cause. However, in some cases, neonatal PH progresses into infancy and childhood where symptoms include failure to thrive and eventually right heart failure or death if left untreated. This chronic condition is termed pulmonary vascular hypertensive disease (PHVD). Although classification and diagnostic criteria have only recently been proposed for pediatric PHVD, little is known about the pathophysiology of chronic neonatal PH, or why pulmonary vascular resistance may remain elevated well beyond infancy. This review explores the many factors involved in chronic PH and what implications this may have on long term outcome when the disease progresses beyond the neonatal period.

Children with acute severe asthma requiring invasive ventilation are among the most difficult to manage in the Intensive Care Unit (ICU). This chapter begins by explaining the pathophysiology of asthma before examining the approaches to its management on the ICU—starting with the evidence for the use of non-invasive ventilation and bronchodilators. Indications for invasive ventilation in acute severe asthma are discussed and important considerations in the conduct of induction of anaesthesia and intubation in this patient group. Ventilation strategies are explored, with particular reference to the concepts of airway resistance, driving pressure, inspiratory flow limitation, and auto-positive end expiratory pressure (PEEP). The use of the mucolytic therapy intratracheal DNAse is discussed, and indications for the use of extracorporeal membrane oxygenation in refractory cases. Finally, the chapter reports on outcomes for children with acute severe asthma and factors associated with higher risk of mortality.

A right aortic arch (RAA) with a left arterial duct (LAD) together encircle the trachea and have the potential to cause tracheobronchial compression and published guidelines recommend bronchoscopy in symptomatic patients. The aim of the study was to describe the incidence of tracheal compression in a cohort of prenatally diagnosed RAA and LAD. Retrospective review of clinical course and imaging of prenatal cases of RAA and LAD assessed with flexible bronchoscopy over an 11-year period. 34 cases of prenatally diagnosed RAA with LAD underwent bronchoscopy at median age of 9 months (range 0.4–123) of whom 11 had respiratory symptoms and 23 were asymptomatic. In the neonatal period, three cases demonstrated respiratory symptoms. An aberrant left subclavian artery (ALSA) was identified in 29 cases. Pulsatile tracheal compression was identified in 32/34 (94%) cases and two cases showed normal tracheal appearances. Significant tracheal compression (> 70% occlusion) was present in 25/34 (74%) cases of which 16 were asymptomatic. Significant carinal compression (> 70% occlusion) was identified in 14/34 (42%) cases, an ALSA was observed in 13/14. Surgical relief of a vascular ring has been performed in 27 (79%) cases at a median age of 15 months (range 0.6–128 months). At surgery, a fibrous remnant of an atretic left aortic arch was identified in 11/27 (41%) cases. Significant tracheal compression may be present in infants even without symptoms. If early relief of airway compression is to be achieved to promote normal development of tracheal cartilage, early bronchoscopy should be considered.

Difficulty in tracheal intubation in paediatric intensive care patients is associated with increased morbidity and mortality. Delays to intubation and interruption to oxygenation and ventilation are poorly tolerated. We developed a safe and atraumatic tracheal intubation technique. A floppy-tipped guidewire and airway exchange catheter were placed to a pre-determined length under bronchoscopic guidance while oxygenation and ventilation was maintained via a supraglottic airway device (SAD). We performed a retrospective review of this technique on patients who were either known to have or who had an unexpected difficultly in intubation. We describe the safety and experience of this in a broad range of critically ill children. Thirteen patients, median (IQR [range]) (9.0 (5.0-10.0 [4.0-12.0]) kg and 15.4 (12.1-23.2 [3.3-49.7]) months) underwent emergency tracheal intubation using this technique, after unsuccessful attempts at intubation using standard laryngoscopy blades. All intubations were successful at the first attempt using this technique and no airway trauma or significant clinical deteriorations were recorded.

Introduction The indications and optimal age for aortopexy remain a subject of debate. Aortopexy is performed in children with moderate to severe airways symptoms (recurrent stridor, need for intubation and ventilation) and tracheomalacia, caused by pulsatile tracheal compression from innominate artery. We report our results with early age aortopexy in patients with and without tracheo oesophageal fistula (TOF). Method Between 2011- 2016, 52 children underwent aortopexy in our centre. Median age at surgery was 9 months. This procedure was performed using a standard open surgical approach, with partial thymectomy and 2–3 sutures placed to lift innominate artery. Twelve patients had tracheopexy at the same time as the aortopexy. Mean follow-up period after surgery was 36 months. We retrospectively collected data on preoperative symptoms, pre and postop bronchoscopy and clinical outcomes. Results The clinical presentation was heterogenous. Patients with associated TOF (23%) had overall more severe symptoms, that occurred in 75% of these cases. The patients without TOF presented with severe symptoms only in 50% of cases. The degree of tracheal/bronchial compression, as assessed by bronchoscopy was: mild (0%–50%) in 6% of the cases, moderate (50%–70%) in 27% and severe (>70%) in 67% of cases. The severity of clinical presentation was significantly corelated with the degree of stenosis (p=0.003). Three cases had failure of aortopexy sutures 3 months post procedure and required repeat procedure. All of these patients had TOF. At last available follow-up: 59.6% patient had a significant improvement, 26.9% had improvement with persisting respiratory symptoms, 9.5% were static and 3.8% died from unrelated causes. Fifteen percent of patients presented at least one life threatening event at any point after surgery. An improvement of the degree of tracheal compression by more than 25% was found in 80% of the patients. Twenty-nine patients (55.7%) had sleep studies. 28.8% of the last sleep studies performed were normal, 13.4% showed mild OSA, 9.6% showed mixed disorder (OSA and Hypoventilation) and 3.8% had central events. Conclusion Aortopexy, as a curative treatment for tracheomalacia produced by tracheal compression, is effective and has low morbidity and mortality from a young age.

Tracheal agenesis (TA) is a rare congenital defect consisting of complete or partial absence of the trachea below the larynx. Antenatal diagnosis is challenging, and most cases are detected in the postnatal period. Airway management of such cases, particularly in the absence of antenatal diagnosis, can be challenging. Various methods of management have been described but with limited success, and overall prognosis remains very poor. We present an unexpected case of TA, highlighting management issues and diagnostic methods.

Objective To evaluate safety, following introduction of standard concentrations of morphine infusions in paediatric critical care. Methods Implementation: A multidisciplinary team was convened, and several workstreams designated, including derivation of concentrations, manufacturing, supply, prescribing, administration using smart pump technology, training and evaluation. Safety Evaluation: Retrieval of all existing data on medication errors linked to morphine use using our hospital incident reporting system and risk assessment of errors in relation to standard concentration implementation. Key findings The pilot identified several areas for improvement, stock control, reasons for reverting from standard to variable concentrations and sources of error. Improvements included the following: refining morphine concentrations and weight limits for bands, pump reprogramming and education. Long-term Safety: Over an 8-year period, 126 morphine-related incidents occurred (two-thirds in the 3 years around introduction). Of note, 67% (85/126) resulted in no patient harm; the remainder 33% resulted in low harm. Analysis of administration errors revealed that up to 70% could be eliminated by refining technology to include bar coding. These included the following: wrong syringe selection (24%), wrong pump mode (28%) and wrong patient weight inputted (18%). Conclusion Introduction of standard infusions is safe and effective. We are exploring ways to further refine safety and extending to other drugs.

Objective To define the associations of a prenatally diagnosed, apparently isolated right aortic arch (RAA) with chromosomal or genetic abnormalities and tracheal compression. Methods This was a retrospective study of apparently isolated RAA assessed by fetal cardiologists and fetal medicine specialists at Kings College Hospital, London between 2000 and 2017. Results The search identified 138 cases of apparently isolated RAA. Invasive testing was performed in 75, and chromosomal or genetic anomalies were identified in 16 (22%), and the most common was 22q11 microdeletion. An aberrant left subclavian artery was seen in 51% of cases. Symptoms of a vascular ring were present in 24 of 97 (25%) children who were reviewed after birth. Bronchoscopy was performed in 33 children, and significant tracheal compression was diagnosed in 28, including 18 of 19 symptomatic and 10 of 14 asymptomatic children. Conclusions An apparently isolated RAA is associated with a high incidence of chromosomal or genetic abnormalities and a high incidence of tracheal compression in symptomatic and asymptomatic patients. Prenatal counselling for genetic associations and postnatal airway assessment in the context of the vascular anatomy is recommended.

Purpose The Technical Performance Score (TPS) performed on pre-discharge echocardiograms developed by Boston Children’s Hospital has been shown to correlate with surgical outcomes. We sought to assess the feasibility and applicability of this in intraoperative imaging in a UK congenital cardiac surgical centre. Methods After training, intraoperative TPS (epicardial and/or transoesophageal) was instituted for all cardiac surgical cases. This was used to inform intraoperative discussions using the previously published scoring system. After the first year, we assessed the relationship between the TPS and basic clinical outcomes. Results From 01/09/15 to 04/07/16 there were 272 TPS procedures in 251 operations. Seven patients had surgery with no documented TPS. Four patients had operations for which there is no current template available. TPS when leaving theatre was: optimal 156 (75%), adequate 34 (16%) and inadequate 18 (9%). Fourteen patients had further runs of cardiopulmonary bypass after an inadequate score, with nine then leaving theatre with an optimal score. There was no significant difference between extubation time for optimal/adequate and inadequate with a median (range) of 1 (0–26 days) and 2.5 (0–11 days) respectively. There were 9 deaths Conclusions Application of intraoperative TPS to a tertiary UK congenital heart surgical centre is feasible and provides a meaningful way of objectively recording intraoperative imaging-based assessment of surgical results. There was no significant difference in extubation times (although these can be affected by factors other than surgical result), nor did an ‘inadequate’ TPS score predict mortality.

Hyperammonaemia is a metabolic emergency and prompt treatment is paramount to optimize neurological outcome. Ammonia is extremely neurotoxic and increased levels can arise from an inherited or acquired defect in hepatic detoxification. Inborn errors of metabolism leading to hyperammonaemia mainly affect the hepatic urea cycle due to single enzyme deficiencies, transporter defects or mitochondrial dysfunction. Primary hyperammonaemia is a consequence of direct urea cycle dysfunction whereas secondary hyperammonaemia can result from disturbance of the urea cycle by toxic metabolites or substrate deficiencies. Immediate recognition and early initiation of specific treatment are of utmost importance. Prognostic factors include duration of hyperammonaemic coma and the extent of ammonia accumulation (Haberle et al. Orphanet J Rare Dis 7:32, 2012). The principles of management in the acute situation aim to rapidly remove ammonia, decrease production and replace rate limiting amino acids.

Fluid overload is a risk factor for poor outcome in intensive care; thus volume loading should be tailored towards patients who are likely to increase stroke volume. We aimed to evaluate the paediatric predictive ability (stroke volume increase of at least 15 % after fluid bolus) of novel and established volumetric and dynamic haemodynamic variables, and assess the influence of baseline contractility on response.We assessed 142 volume loading episodes (10 ml/kg crystalloid) in 100 critically ill ventilated children, median (interquartile) weight 10 (5.6-15) kg. Eight advanced haemodynamic variables were assessed using two commercially available devices. Systemic ventricular contractility was measured as the maximum rate of systolic arterial pressure rise.Overall, predictive ability was poor, with volumetric variables performing better than dynamic (area under receiver operating characteristic curves ranged from 0.53 to 0.67). The best predictor was total end-diastolic volume index; however, this did not increase in a consistent way with volume loading, with change post volume being weakly related to baseline values (r = -0.19, p = 0.02). A multivariable model quantified the importance of contractility in stroke volume response. Children with high baseline contractility (≥75th centile) typically achieved a positive stroke volume response when end-diastolic volume values changed by 10-15 ml/m(2.6), whereas patients with low contractility (≤25th centile) typically required end-diastolic volume increases of 35-40 ml/m(2.6).Current paediatric predictors of volume response perform poorly; prediction may be improved if baseline contractility is taken into account.

The purpose of this study was to investigate the qualitative and quantitative accuracy of transpulmonary ultrasound dilution (UD) (COstatus™, Transonic Systems) for the detection of small anatomic shunts. It was a prospective, observational study in a multi-disciplinary pediatric intensive care unit. Seventy-three critically ill children (67 post cardiac surgery), with a median (IQR) age of 10 (3-50.3) months and a median (IQR) weight of 8 (3.43-13) kg were enrolled. Ultrasound dilution (UD) measurements were performed on patients within 1 h of undergoing two-dimensional echocardiography, which was used as the comparator technique. Shunt was diagnosed by characteristic changes on the UD curve shape, and was considered "test-positive" only if two or more measurements suggested the presence of the shunt. The UD technology also provided an estimate of pulmonary to systemic blood flow ratio (Qp:Qs). 12/73 (16.4 %) patients had a shunt identified by both UD and echocardiography. The overall accuracy (95 % CI) was 86.1 % (75.6-96.6 %), with a sensitivity of 85.7 % (57.2-98.2 %) and specificity of 86.4 % (75.0-94.0 %). The estimated Qp:Qs ranged from 0.7 to 1.4, which was consistent qualitatively with the echocardiographic findings on color flow doppler. Shunt was detected by UD alone in eight children; six of these had clinical conditions known to compromise dilution curve analysis (valve regurgitation, asymmetric pulmonary blood flow). Shunt was detected by echocardiography alone in two children; in both cases the shunt was tiny. UD is an accurate method for the detection of small anatomical shunts, both qualitatively and quantitatively.

Objective Prior to Norwood 1 surgery, neonates with hypoplastic left heart syndrome (HLHS) are at risk of decompensation from systemic underperfusion secondary to pulmonary overcirculation. We examined whether preoperative temporal profiles of physiological and laboratory variables differed between neonates who did and did not decompensate preoperatively. Design Case control study. Setting Paediatric Intensive Care Unit, 2002–2013. Patients Eighty-five neonates with HLHS, matched by birth weight and admission date. Measurements Decompensation was defined as the need for emergency intubation and ventilation due to clinically diagnosed impaired systemic oxygen delivery. The end point was time of decompensation (cases, n=33) or discharge for surgery (controls, n=52). Variable trajectories were modelled non-linearly using generalised estimating equations. Results Decompensation occurred on median (IQR) day 3 (2–4) of life in cases, with surgery occurring on day 4 (3–7) in controls. Oxygen saturation and blood pressure trajectories were identical between groups (p>0.2). Heart and respiratory rates increased with time overall, but significantly faster in cases than controls; by an average of 4.0 bpm/day versus 1.4 bpm/day (p=0.002) and 5.3 respirations/minute/day versus 1.5 respirations/minute/day, respectively, (p=0.003). Although metabolic blood gas components began to decline subtly 24 h before clinical decompensation, they remained in the normal range for much of this period. Conclusions Heart and respiratory rates, and metabolic acid base trajectories show subtle differences prior to decompensation in neonates with HLHS. These findings highlight the importance of evaluating rates of change rather than absolute values of physiological and laboratory variables.

Blood lactate has become easy to measure, with results now readily available to us in clinical practice from point-of-care testing and blood gas analysers. It has long been recognised that hyperlactataemia in acutely unwell patients is associated with poorer outcomes,1 but its interpretation and clinical significance is not always clear. In this review article, we present the evidence for the use of lactate as a diagnostic and therapeutic marker in acutely unwell children. Lactate (2-hydroxypropanoic acid) is produced by glycolysis—glucose oxidation—from pyruvate, via the enzyme lactate dehydrogenase, which is located in the inner mitochondrial membrane.2 The terms ‘lactate’ and ‘lactic acid’ are often used interchangeably, but strictly speaking, at physiological pH, lactic acid is almost completely dissociated from its protons.3 The name originates from its initial discovery, in 1780, from samples of sour milk, and it was first isolated from blood in 1843 from women who died from puerperal sepsis.4 ,5 Historically, lactate was considered to be a ‘waste product’ of anaerobic metabolism and assumed to be a surrogate marker for tissue perfusion.1 However, more recent evidence has challenged these classic views. Lactate is now understood to be a valuable metabolic fuel, not necessarily associated with dysoxia, particularly in energy-intense organs such as the brain and skeletal muscle.6 ,7 It also plays an important role in cell signalling, via transporter proteins which shuttle lactate between cells.7 ,8 The familiar classification of lactic acidosis into type A (associated with hypoxia) and type B (in the absence of hypoxia)9 is somewhat limited, and fails to address the complexity of its physiology. Lactate is continually produced and turned over rapidly, even at rest,4 ,8 and baseline blood levels of 0.5–1.8 mmol/L reflect the global balance between lactate production and consumption.10 …

Pressure recording analytical method (PRAM) is a novel, arterial pulse contour-based method for measuring cardiac output (CO). Validation studies of PRAM in children are few, and have not assessed both absolute accuracy and ability to track changes in CO across a broad case mix. We aimed to compare CO as measured by PRAM with that using a transpulmonary dilution method in a cohort of critically ill children.Forty-eight, mechanically ventilated children with a median (inter-quartile) weight of 10.7 (5.5-15) kg with arterial and central venous catheters in situ were studied. CO was measured simultaneously using PRAM and the comparator method, transpulmonary ultrasound dilution (UD). Measurements were repeated before and after therapeutic interventions that were intended to augment CO (e.g. fluid bolus).In total, 210 paired measurements were compared. The mean (sd) CO was 1.9 (1.2) litre min(-1) with UD when compared with 1.92 (0.5) litre min(-1) using PRAM. The mean bias was 0.02 litre min(-1) with wide limits of agreement: ± 2.21 litre min(-1), giving a percentage error of 116%. The concordance between PRAM and UD for measuring changes in CO was also poor, with only 37% of measurements falling within the pre-defined polar plot limits of ±30°.There is an unacceptably poor agreement between UD and PRAM. We do not recommend the use of PRAM for measuring CO in critically ill children with the current algorithm.

Central airway obstruction (trachea and major bronchi) in neonates can be caused by malacia, stenosis, or compression by masses or vascular structures. These abnormalities may be present in the neonatal period but are typically not detected until at least 6 months of age. We present four patients (1.6-4.1 kg, 32-41 weeks gestation) with nonspecific symptoms (e.g., poor weight gain, difficulty weaning from CPAP) who underwent bronchoscopy in the neonatal period. Critical airway obstruction (>90%) was identified in these relatively asymptomatic neonates. We suggest a low threshold for investigation with bronchoscopy in high-risk neonates. Pediatr Pulmonol. 2017;52:E15-E17. © 2016 Wiley Periodicals, Inc.

Introduction Paediatric tracheobronchomalacia is a rare but potentially serious condition. Severe tracheobronchomalacia requires intervention or operation. This is an evaluation of a ten-year experience at an institution. Methods In this retrospective study all patients were included that required an intervention for severe tracheobronchomalacia from 2003 to 2012. Symptoms, aetiology, comorbidities, localisation of the malacia, age at diagnosis, therapeutic measures and associated complications were evaluated. Results Forty-four patients with severe tracheobronchomalacia underwent intervention/operation. The predominant aetiology was vascular compression in 48%. The majority of patients had complex comorbidities, most importantly cardiac pathology in 66%. The median age at diagnosis was 3 months. A total of 17 aortopexies, 21 tracheostomies and 25 stent placements were performed. The mean follow-up was 2.6 years. Severe complications occurred in 12 patients. The most common complications were stent obstruction/fracture and tracheostomy tube obstruction. Conclusion The management of severe tracheobronchomalacia is complex and the population of patients is very heterogeneous. Therefore the treatment has to be adapted for each patient individually. The decision strategies are discussed in this article. The surgical techniques for placement and safe removal of expandable bare metallic stents employed in our institution are presented. A multidisciplinary team of ENT surgeons, Intensivists, Cardiologists and Cardiac surgeons is of great importance.

This is a case report formatted as a clinical handover discussion between a junior ward paediatrician (SB) and senior paediatric intensive care consultant (AD) and cardiology consultant (GM). SB : I have been handed over a 3-year-old patient from the paediatric intensive care unit (PICU). She has a complex medical history and spent the first year of her life in PICU. She had a repair of a hypoplastic-aortic-arch and a tracheo-oesophageal fistula as a neonate but remained ventilator dependent for months with left main bronchus (LMB) compression. Separation from the ventilator was eventually achieved, after a failed aortopexy, with a 20×6 mm Palmaz metallic stent inserted into the LMB. This permitted discharge home for 2 years but she gradually outgrew the neonatal stent, which had become embedded within the LMB. She represented with recurrent chest infections and left lung collapse, thus necessitating removal and replacement of the LMB stent. The patient also had aortic valve stenosis and required corrective open heart surgery. As she was undergoing bypass, it was decided to remove the embedded bronchial stent during the valve repair. During bypass surgery, a small bronchial incision was made through which the embedded stent was removed. Due to heparinisation, the procedure was complicated by significant mucosal bleeding into the LMB, which filled the left lung with blood. Postprocedure, the left lung remained opacified on X-ray (figure 1A). The PICU team were unable to open the lung despite physiotherapy, saline lavage, bronchoscopy and high-pressure dual lung ventilation. However, she has been transferred to the ward self-ventilating in air and her last chest X-ray showed reinflation of the left lung, how was this achieved given that all conventional methods failed? Figure 1 (A) Collapsed left lung immediately following cardiac bypass and surgical removal of left main bronchus (LMB) stent; (B) perfluorocarbon (PFC) instillation into the …

To report on the monitoring of diaphragm electrical activity (Edi) using neurally adjusted ventilator assist (NAVA) technology to investigate the mechanisms of ventilator dependence in children with neuromuscular and respiratory control disorders.Using NAVA technology, electrical activity of the diaphragm (Edi) was monitored at the lowest achievable level of respiratory support in six ventilator-dependent patients with neuromuscular and respiratory control disorders, aged 6 weeks to 12 years, admitted to a tertiary paediatric intensive care unit between 2009 and 2011.Edi monitoring identified markedly abnormal respiratory dynamic patterns that were not always apparent clinically. These were associated with disorders of central respiratory control, muscle weakness and diaphragm pathology.Edi monitoring using NAVA technology is a valuable, minimally invasive, diagnostic adjunct in children with neuromuscular and respiratory control disorders who are ventilator-dependent.

Background— Observational studies in adults have shown a worse outcome associated with hyperoxia after resuscitation from cardiac arrest. Extrapolating from adult data, current pediatric resuscitation guidelines recommend avoiding hyperoxia. We investigated the relationship between arterial partial oxygen pressure and survival in patients admitted to the pediatric intensive care unit (PICU) after cardiac arrest. Methods and Results— We conducted a retrospective cohort study using the Pediatric Intensive Care Audit Network (PICANet) database between 2003 and 2010 (n=122 521). Patients aged o 2 ≥300 mm Hg) and 448 (24%) had hypoxia (Pa o 2 o 2 and PICU mortality. After covariate adjustment, risk of death increased sharply with increasing hypoxia (odds ratio, 1.92; 95% confidence interval, 1.80–2.21 at Pa o 2 of 23 mm Hg). There was also an association with increasing hyperoxia, although not as dramatic as that for hypoxia (odds ratio, 1.25; 95% confidence interval, 1.17–1.37 at 600 mm Hg). We observed an increasing mortality risk with advancing age, which was more pronounced in the presence of congenital heart disease. Conclusions— Both severe hypoxia and, to a lesser extent, hyperoxia are associated with an increased risk of death after PICU admission after cardiac arrest.

Children with Down syndrome (DS) have several genetic anomalies within chromosome 21 which may influence their response to critical illness. We compared the intensive care course and outcome of children with DS versus those without. Retrospective cohort study in four English paediatric intensive care units (ICUs) (2003–2009, n = 33,485). We examined, via a competing risks model, whether risk (subhazard) for ICU mortality differed for children with DS, after adjusting for important confounders. DS patients exhibited lower disease severity at ICU admission but subsequently required a higher proportion of cardiovascular support, and similar renal support to non-DS patients. Children with DS (n = 1,278) had lower crude mortality than those without (4.2 versus 6.2 %, p = 0.003). This was not significant when expressed as standardized mortality ratio: 0.83 [95 % confidence interval (CI) 0.63–1.09] versus 0.90 (95 % CI 0.86–0.94). However, the competing risks model showed that mortality risk was influenced by length of ICU stay. At admission, DS patients exhibited a subhazard for mortality of 0.63 (95 % CI 0.46–0.85), which increased to 1.00 by day 10 of admission, and continued rising above that of non-DS children thereafter. Children with DS require a higher proportion of organ support than expected by disease severity at ICU admission. In addition, the mortality risk for children with DS is dependent upon length of ICU stay. These findings could reflect differences in case mix, but are also compatible with different response to critical illness in this group.

Stenting the atrial septum to achieve decompression of the atrium is well described and commonly performed via a percutaneous catheter approach under combined fluoroscopic and echocardiographic guidance. We describe two successful cases of a hybrid approach to atrial stenting under echocardiographic guidance alone, as a viable alternative approach.

Cerebral oedema is a potentially devastating complication of diabetic ketoacidosis (DKA). The relationship between osmolar changes, acid-base changes and development of cerebral oedema during therapy is unclear.Retrospective cohort study on 53 children with severe DKA (mean pH at presentation 6.92±0.08). Cerebral oedema was diagnosed using neurological status, response to osmotherapy, and neuroimaging, and classified as: early (occurring ≤1 h after presentation, n=15), late (1-48 h, n=17) or absent (controls, n=21). The temporal profiles for various osmolar and acid-base profiles were examined using a random coefficients fractional polynomial mixed model, adjusted for known risk factors.The three groups could not be differentiated by demographic, osmolar or acid-base variables at presentation. All osmolar and acid-base variables showed non-linear temporal trajectories. Children who developed late onset oedema showed dramatically different temporal profiles for effective osmolality and glucose-corrected serum sodium (both p0.001). Glucose-corrected sodium provided better qualitative discrimination, in that it typically fell in children who developed late oedema and rose in controls. The maximum between-group difference for both variables approximated the median time of clinical cerebral oedema onset. Blood glucose and acid-base temporal profiles did not differ between the groups. Late onset oedema patients received more fluid in the first 4 h, but this did not influence the osmolar or glucose-corrected sodium trajectories in a predictable fashion.Glucose-corrected serum sodium may prove a useful early warning for the development of cerebral oedema in DKA.

Pulmonary artery (PA) banding has been established as a palliative surgical technique for congenital heart defects for over 50 years [1]. With the advent of earlier corrective surgery, the indications for PA banding have changed over time [2, 3]. Currently these include: (a) limitation of pulmonary blood flow in the setting of an excessive left-toright shunt; (b) regulation of pulmonary blood flow in the univentricular circulation; and (c) a training procedure for the left ventricle prior to conversion to the systemic pumping chamber (late presentation of D-transposition of the great arteries, or prior to a double-switch procedure with L-transposition).

Unplanned extubation (UE) is an important paediatric intensive care unit (PICU) quality indicator. Studies on UE have been modest in size, with accurate UE rate calculation potentially hampered by ventilation episodes recorded in calendar days. We wished to document UE rates, outcomes, associated factors and quantify error when calendar days rather than exact timings are used. We recorded prospectively all UE episodes and potential associated factors in our 20-bed PICU for 12,533 admissions (2000–2013). Ventilation episodes were recorded to the minute, with non-invasive and tracheostomy ventilation excluded. Analysis utilised multilevel mixed-effects Poisson regression, adjusting for multiple ventilation episodes in the same patient. Overall, 243 UEs occurred within 14,141 ventilation episodes (31,564 intubated days), giving a UE rate of 0.77 (95 % CI 0.67–0.87) episodes per 100 intubated days. If calendar ventilation days were used, the yearly UE rate was underestimated by 27–35 %. UE rates decreased with time, by approximately 0.05/100 intubated days each year. Associations with UE incidence rate included patient age, source of admission, disease severity and diagnostic category, with nasal tubes decreasing the risk. Although UE versus planned extubation was associated with a higher re-intubation rate (43 versus 8 %) and longer median PICU stay (4.6 versus 2.6 days, p

A total of 8 infants presenting with sepsis-like illness were diagnosed to have human parechovirus (HPeV) infection; of which, 5 had abdominal distension and 6 had an erythematous rash. A combination of abdominal distension and erythematous rash was observed in 4 infants. The abdominal symptoms can be very prominent and signs could be confused with acute surgical conditions. Although fever and central nervous symptoms are important features, a red rash with abdominal distension and a low C-reactive protein value and lymphocyte count can be clues to recognize this infection.

Background Clonidine is a useful analgesic-sedative agent; however, few data exist regarding its use in infants after congenital heart disease surgery. We thus aimed to assess the absorption and safety of enterally administered clonidine in this setting. Methods Sixteen infants (median age 6.7 months) received a single nasogastric dose of 3 μg kg −1 clonidine 2–6 h after surgery. Blood samples were obtained at seven time intervals (up to 480 min). Plasma concentration profiles were obtained, and then pooled with a previous study (137 samples, 30 infants) for estimation of population pharmacokinetic parameters (NONMEM version 7.2). Results Enteral absorption showed considerable inter-individual variability, with clonidine C max ranging from 0.15 to 1.55 ng ml −1 (median 0.73), and T max from 12 to 478 min (median 190). Although therapeutic sedative plasma concentrations were achieved in 94% of patients, only half had attained this by 70 min post-dose. Patients who did not receive inotropes exhibited a positive association between cumulative morphine dose and T max (interaction effect P =0.03); this was not seen among those receiving inotropes. The haemodynamic profile was favourable; few patients required fluid boluses, and this bore no relationship to plasma clonidine concentration. Population pharmacokinetic parameter estimation yielded results similar to previous paediatric studies: clearance 13.7 litre h −1 70 kg −1 and V d 181 litre 70 kg −1 . Conclusions Early postoperative enteral clonidine produces favourable haemodynamic profiles and therapeutic plasma concentrations in the majority of cardiac surgical infants; however, the time to achieve this can be erratic. Thus, parenteral administration may be preferable if rapid analgo-sedative effects are needed.

Sedation and analgesia using opioids and benzodiazepines is frequently required in critically ill children to minimize pain and anxiety. In some patients, difficult sedation occurs when tolerance or unacceptable side effects limit the efficacy of conventional analgo-sedative treatment. We describe seven patients (age range 1 to 17 yr) where difficult sedation was successfully managed with enteral levomepromazine (LMZ). LMZ is a neuroleptic antipsychotic agent that exhibits potent analgo-sedative properties without respiratory depression, through non-opioid and non-benzodiazepine pathways. We describe its use in our pediatric intensive care unit to control agitation in patients with known behavioral disorders who frequently pose a significant sedation challenge. We also illustrate its successful use in cases of withdrawal syndrome and delirium, and discuss the association of fever and its distinction from neuroleptic malignant syndrome in two patients. LMZ should be considered as a useful sedative in critically ill children where difficult sedation occurs and conventional agents are exhausted.

Stenting the atrial septum to achieve decompression of the atrium is well described and commonly performed via a percutaneous catheter approach under combined fluoroscopic and echocardiographic guidance. We describe two successful cases of a hybrid approach to atrial stenting under echocardiographic guidance alone, as a viable alternative approach.

Recognition and early management of children at risk of injury to the cervical spinal cord is lacking

Mutations in the αB-crystallin (CRYAB) gene, encoding a small heat shock protein with chaperone function, are a rare cause of myofibrillar myopathy with autosomal-dominant inheritance, late-onset and moderate severity. We report a female infant presenting from 4 months with profound muscle stiffness, persistent creatine kinase elevation and electromyography characterized by spontaneous electrical activity and pseudomyotonic discharges. Muscle biopsy suggested a myofibrillar myopathy and genetic testing revealed homozygosity for the CRYAB mutation c.343delT (p.Ser115ProfsX14). These findings suggest a severe, recessively inherited form of CRYAB-related myofibrillar myopathy. Profound muscle stiffness as the main presenting feature indicates αB-crystallin as a potent modifier of muscle contractility.

BACKGROUND: Mediastinal bleeding is common after pediatric cardiopulmonary bypass (CPB) surgery. Thromboelastography (TEG ® ) may predict bleeding and provide insight into likely mechanisms. We aimed to (a) compare perioperative temporal profiles of TEG ® and laboratory hemostatic variables between patients with significant hemorrhage (BLEED) and those without (CONTROL), (b) investigate the relationship between TEG ® variables and routine hemostatic variables, and (c) develop a model for prediction of bleeding. METHODS: TEG ® and laboratory hemostatic variables were measured prospectively at 8 predefined times for 50 children weighing

Once-daily gentamicin therapy is becoming increasingly common in pediatric practice; however, little is known about pharmacokinetics in critical illness. Gentamicin exhibits concentration dependant killing; thus, peak serum concentrations at least eight times higher than minimum inhibition concentration of the target organism have been recommended. We wanted to derive pharmacokinetic parameters for gentamicin in critical illness and to evaluate whether a dose of 8 mg/kg provides an adequate peak serum concentration (16 mg/L).Population-based pharmacokinetic analyses were undertaken using therapeutic drug monitoring data collected prospectively in an intensive care unit over 6 months (n = 50 children). Monte Carlo simulations were used to estimate the probability of achieving 1) peak concentrations16 mg/L; and 2) trough concentrations2 mg/L at 24 and 36 hrs.The optimal pharmacokinetic model was of two-compartment disposition with zero order input and additive residual error. Weight was associated nonlinearly with clearance and linearly with volume, and age was a significant covariate for clearance. An 8-mg/kg dose provided near 100% probability of achieving adequate peak concentrations at all ages. However this probability decreased rapidly at doses7 mg/kg with neonates being the most susceptible. Approximately 50% of nonpremature neonates within the first week of life, 25% of infants, and 10% of children are likely to need a dose interval24 hrs.A gentamicin dose of 8 mg/kg is highly likely to achieve peak concentrations16 mg/L in critically ill children. A considerable proportion will require dose intervals24 hrs; thus, therapeutic drug monitoring is essential.

Metabolic acidosis is common in septic shock, yet few data exist on its etiological temporal profile during resuscitation; this is partly due to limitations in bedside monitoring tools (base excess, anion gap). Accurate identification of the type of acidosis is vital, as many therapies used in resuscitation can themselves produce metabolic acidosis.Retrospective, cohort study.Multidisciplinary pediatric intensive care unit with 20 beds.A total of 81 children with meningococcal septic shock.None.Acid-base data were collected retrospectively on 81 children with meningococcal septic shock (mortality, 7.4%) for the 48 hrs after presentation to the hospital. Base excess was partitioned using abridged Stewart equations, thereby quantifying the three predominant influences on acid-base balance: sodium chloride, albumin, and unmeasured anions (including lactate). Metabolic acidosis was common at presentation (mean base excess, -9.7 mmol/L) and persisted for 48 hrs. However, the pathophysiology changed dramatically from one of unmeasured anions at admission (mean unmeasured anion base excess, -9.2 mmol/L) to predominant hyperchloremia by 8-12 hrs (mean sodium-chloride base excess, -10.0 mmol/L). Development of hyperchloremic acidosis was associated with the amount of chloride received during intravenous fluid resuscitation (r = .44), with the base excess changing, on average, by -0.4 mmol/L for each millimole per kilogram of chloride administered. Hyperchloremic acidosis resolved faster in patients who 1) manifested larger (more negative) sodium chloride-partitioned base excess, 2) maintained a greater urine output, and 3) received furosemide; and slower in those with high blood concentrations of unmeasured anions (all, p.05).Hyperchloremic acidosis is common and substantial after resuscitation for meningococcal septic shock. Recognition of this entity may prevent unnecessary and potentially harmful prolonged resuscitation.

To demonstrate the diagnostic yield, therapeutic role and safety of flexible bronchoscopy via an intensivist-led service in critically ill children. Retrospective chart review. Regional paediatric intensive care unit. One hundred forty-eight flexible bronchoscopies were performed by two intensivists on 134 patients (median age 16.5 months) over a 2.5-year period. Eighty-eight percent of patients required mechanical ventilation, and 22% were receiving inotropes. Case mix included general (n = 77), cardiac surgery (n = 18), cardiology (n = 13), ear-nose-and-throat surgery (n = 17), oncology (n = 8) and renal (n = 1). The indication for bronchoscopy was defined a priori according to one of four categories: suspected upper airway disease (n = 32); lower airway disease (n = 70); investigation of pulmonary disease (n = 25); and extubation failure (n = 21). Bronchoscopy was generally performed soon after PICU admission, at a median time of 1.5 days for the former three categories, and 4 days for extubation failure group. A positive yield from bronchoscopy (diagnosis that explained the clinical condition or influenced patient management) was present in 113 of 148 (76%) procedures, varying within groups from 44% (pulmonary disease) to 90% (extubation failure).Ten percent of patients developed a fall in oxygen saturations > 20% during the procedure and 17% required a bolus of at least 10 ml/kg of 0.9% saline for hypotension. Critically ill patients with respiratory problems may benefit from a PICU-led bronchoscopy service as the yield for positive bronchoscopic finding is high, particularly for upper airway problems or extubation failure.

Introduction The base deficit is a useful tool for quantifying total acid–base derangement, but cannot differentiate between various aetiologies. The Stewart–Fencl equations for strong ions and albumin have recently been abbreviated; we hypothesised that the abbreviated equations could be applied to the base deficit, thus partitioning this parameter into three components (the residual being the contribution from unmeasured anions). Methods The two abbreviated equations were applied retrospectively to blood gas and chemistry results in 374 samples from a cohort of 60 children with meningococcal septic shock (mean pH 7.31, mean base deficit -7.4 meq/L). Partitioning required the simultaneous measurement of plasma sodium, chloride, albumin and blood gas analysis. Results After partitioning for the effect of chloride and albumin, the residual base deficit was closely associated with unmeasured anions derived from the full Stewart–Fencl equations (r2 = 0.83, y = 1.99 – 0.87x, standard error of the estimate = 2.29 meq/L). Hypoalbuminaemia was a common finding; partitioning revealed that this produced a relatively consistent alkalinising effect on the base deficit (effect +2.9 ± 2.2 meq/L (mean ± SD)). The chloride effect was variable, producing both acidification and alkalinisation in approximately equal proportions (50% and 43%, respectively); furthermore the magnitude of this effect was substantial in some patients (SD ± 5.0 meq/L). Conclusion It is now possible to partition the base deficit at the bedside with enough accuracy to permit clinical use. This provides valuable information on the aetiology of acid–base disturbance when applied to a cohort of children with meningococcal sepsis.

Objective: To determine the effect of gastric feeding on the measurement of gastric intramucosal PCO 2 (PiCO 2 ) and its derived gastric intramucosal PCO 2 -arterial PCO 2 difference (PiCO 2 -PaCO 2 difference) and gastric intramucosal pH (pHi) in a group of critically ill children using recirculating gas tonometry. Design: Prospective clinical pilot study. Setting: Sixteen bed pediatric intensive care unit. Patients: Ten mechanically ventilated and hemodynamically stable children (median age, 20.1 months [interquartile range (IQR), 9.7-47.6 months] and median weight, 10.2 kg [IQR, 10-16.5 kg]). Interventions: A 7-French recirculating gas tonometer was placed in the stomach via the orogastric route. Measurements: In each patient, baseline fasted/unfed PiCO 2 , PiCO 2 -PaCO 2 difference, and pHi were determined hourly over a 5-hr period. Gastric feeding was then reestablished (3 mUkg/hr) within a median time of 3 hrs and a further 5 hourly measurements were determined. Concurrent arterial blood gas and lactate measurements were taken. Blood pressure and heart rate was monitored throughout. Main Results: Hemodynamic parameters remained stable throughout the study period. When compared with the unfed/ fasting state, PiCO 2 measurements and PiCO 2 -PaCO 2 difference were consistently lower and pHi values higher than when the patients were fed (two-way analysis of variance for repeated measures: all p

Objective To describe a case of massive diltiazem overdose with a good outcome achieved after early and aggressive supportive therapy. Design Case report. Setting Pediatric Critical Care Unit. Patient Sixteen-year-old adolescent girl. Measurements and main results A 16-yr-old adolescent girl presented to the emergency department 6 hrs after the intentional ingestion of 40 300-mg sustained-release diltiazem tablets (12 g of Cardura CD). She was hypotensive and required a glucagon and epinephrine infusion despite initial fluid resuscitation with saline and intravenous calcium (1 g). Multiple asystolic cardiac arrests ensued which became increasingly refractory to high-dose epinephrine. Hemodynamic support was achieved with a 48-hr period of extracorporeal membrane oxygenation for atrial standstill. Severe multiorgan dysfunction ensued (cardiac, neurologic, renal, hepatic, gastrointestinal, hematologic, and metabolic). Plasma diltiazem and its metabolites were measured and its half-life was reported between 28 and 48 hrs. A sustained decline in plasma diltiazem levels and its metabolites was not observed after two periods of charcoal hemoperfusion. Recovery of organ function occurred with sinus rhythm noted on the ninth day. The patient made a full recovery and was discharged from the critical care unit after 15 days. Conclusions Although massive calcium channel blocker overdose can produce profound and prolonged cardiac or multiorgan dysfunction, its toxic effects may be reversible. Supportive therapy, particularly of the cardiovascular system, is the most important goal.

Objective: To determine whether introduction a new feeding guideline based upon individual gastric emptying times provides a higher proportion of enteral feeding. Methods: A prospective audit in a 20-bed PICU was conducted one year before (March 2007) and after (March 2009) introduction of the new guideline (March 2008). Data were collected over 4 days per patient on 76 patients in 2007 (37 cardiac, 39 general), and 78 patients in 2009 (39 cardiac, 39 general), comprising 9339 PICU hours. In 2009, the feeding interval was based upon individualised gastric emptying time, calculated after a test feed. Results: The proportion of potential enteral calories given to cardiac patients increased from 39.8% in 2007 to 60.7% in 2009, p < 0.001). A smaller increase was seen for general patients (62.1% to 66.6%, p < 0.001). The median (interquartile) time from admission to establishing full feeds reduced from 23 (12 - 49) to 13 (8 - 24) hours for cardiac (p = 0.007) and from 17 (8 - 32) to 8 (5 - 20) hours (p = 0.05) for general patients. The impact of the feeding guideline on time to establish full feeds remained significant (p < 0.001) after multivariable adjustment for mortality risk (PIM2), diagnosis, weight and gender. By 2009, the major reasons for not feeding were largely unavoidable (including nil by mouth peri-procedure, gut pathology). Conclusions: Introduction of a new feed in guideline appeared to result in earlier and more effective establishment of enteral feeding.

Dear Editor, The use of clinical information systems (CIS) and electronic prescribing have been shown in single centre studies to improve access to vital data, enhance patient safety and reduce manual documentation time in critical care [1, 2]. There are few large-scale reports of CIS utilisation in paediatric intensive care units (PICU). As part of the Informatics subgroup of the UK Paediatric Intensive Care Society, we conducted a national survey to study the distribution, characteristics and satisfaction with existing electronic systems. Lead intensivists, nurses and/or data managers from the Paediatric Intensive Care Audit Network (PICANet) [3] were invited to complete a self-administered questionnaire survey in September 2007, either online (QuestionPro, http://www. questionpro.com), on an emailed portable document format (PDF) form or on paper. Questions focused on: (a) use of hospital-wide electronic systems; (b) clinical functionality available in PICU systems; (c) data security; (d) research and audit; (e) user satisfaction measured on a Likert scale (1, very satisfied; 5, very dissatisfied); and (f) future plans for CIS implementation. Data were analysed at the unit level, except satisfaction scores, which were analysed at the respondent level. Characteristics of participating units (admission numbers, number of beds and unit type) were obtained from PICANet. Group-wise differences were analysed by using the chi-square test; Wilcoxon sign rank test was used for satisfaction scores. Fifty respondents from 28 out of 32 UK PICUs completed the survey (response rate 88%). Intensivists and nurses comprised the majority of subjects (62%). One-third of the units admitted more than 500 patients/ year, the majority being combined medical-surgical units. More than 80% of the units used hospital-wide systems for patient admission/discharge, radiology and laboratory results. In addition, units used a mixture of small locally developed (16/28) and commercial databases (8/28) with widely varying clinical functionality. Only one unit had gone ‘‘paperless’’ by implementing an integrated CIS with charting, clinical documentation and prescribing functions. In general, larger units were more likely to adopt more functional, commercial systems rather than ‘‘home-grown’’ databases (p \ 0.05). Clinical functionality provided by the various PICU systems is summarised in Table 1. In addition to clinical systems, a number of separate research and audit databases were also used to store data on specific patient groups (e.g. sepsis or extracorporeal membrane oxygenation) resulting in significant duplication of data entry and storage. No significant differences were seen between satisfaction levels of doctors and nurses, although ‘‘home-grown’’, less functional systems scored marginally higher satisfaction levels than commercially procured systems (median 2.5 vs. 2.0). Nevertheless, 5 PICUs reported plans to procure fully functional CIS within a year of the survey. Our study demonstrates poor uptake of CIS in UK PICUs, with larger units more likely to invest in clinical systems and smaller units

Objective: To report the dramatic resolution of unilateral mucus plugging and atelectasis in a mechanically ventilated child with refractory status asthmaticus after intratracheal recombinant human DNase (rhDNase) therapy. Design: Case report. Setting: Critical care unit. Patient: A 7-yr-old boy with status asthmaticus, severe respiratory failure and barotrauma unresponsive to conventional therapy. Fiberoptic bronchoscopy confirmed widespread mucus impaction of the subsegmental bronchi of the left lung without response to bronchoscopic lavage. Interventions: Two 10-mg doses of intratracheal rhDNase were administered 8 hrs apart. Main Results: The left-sided atelectasis resolved 3 hrs after the first dose of rhDNase. Improvements in gas exchange and tidal volumes were sustained and particularly noticeable after the second dose. The patient was successfully extubated 26 hrs after receiving the rhDNase treatment without any adverse effects. Conclusions: rhDNase should be considered as a potential therapy for refractory mucus plugging and atelectasis in intubated patients with status asthmaticus.