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Neonates with critical heart disease are at risk of significant deficiencies in systemic oxygen delivery. The incidence and clinical pattern of hyperlactatemia in neonates presenting with critical heart disease has not been described. We reviewed the lactate pattern of neonates transferred to our cardiac intensive care unit for surgical management of their heart disease over a 1-year period. Stabilization of these neonates began in the referring institutions. From 8/4/03 to 8/4/04, 75 neonates with critical heart disease were transferred to our unit for stabilization and subsequent surgery. Blood lactate was measured on admission and subsequently in any patient thought to be at risk of low systemic oxygen delivery. Lactate was measured in 59 patients on admission and in 63 patients within the first 48 h of admission. Median age on admission was 1 day (range 0–13). Median age at surgery was 8 days (range 1–30). Median length of stay was 20 days. Peak lactate was noted on admission in 51 patients, and at 12–24 h in 8 patients. Mild hyperlactatemia (2.3–5 mmol/l) was present in 30 patients on admission and moderate-to-severe hyperlactatemia (≧5 mmol/l) was present in 8 patients. Mean lactate level on admission was 3.1 ± 0.6 mmol/l, and this did not return to normal (

Patients undergoing congenital heart surgery may occasionally require additional surgical procedures in the form of tracheostomy and gastrostomy. These procedures are often performed in an attempt to diminish hospital morbidity and length of stay. We reviewed the Web-based medical records of all patients undergoing congenital heart surgery at Miami Children’s Hospital from February 2002 through August 2007. Patients who were deemed preterm and had undergone closure of a patent ductus arteriosis were eliminated. The records of all other patients were queried for the terms gastrostomy, g-tube, Nissan, fundal plication, tracheostomy, or tracheotomy. Patients’ medical records in which these terms appeared in any portion were completely reviewed. There were 1660 congenital heart operations performed in the study period. There were 592 operations performed on patients whose age ranged from 1 month to 1 year and 441 neonatal operations. Mortality was 2%. Median postoperative stay was 8 days (range, 1–191 days), 12 days for neonates (range, 3–142 days), and 19 days for neonates undergoing RACHS-1 category 6 operations (range, 4–142 days). Tracheostomies were performed in four patients (0.2%). Gastrostomies were performed on eight patients (0.4%), representing 0.8% of patients

We conducted a study with the objective of comparing the performance of two different systems for patient-triggered ventilation in neonates (impedance versus flow/volume-triggered) by measuring response time, autotrigger and trigger failure rates, ventilation, and gas exchange. The two ventilator systems were applied in random order in 10 preterm neonates (median gestational age: 30.5 wk; range: 27 to 34 wk; body weight: 1,266 g; range: 840 to 2,240 g) using identical ventilator settings. The median (range) response time was 169 (98 to 305) ms for the impedance system and 115 (79 to 184) ms for the flow/volume system (p < 0.01). The longer and more variable response time of the impedance system was secondary to a phase lag of the impedance signal caused by chest wall distortion. Although 13.1 (0.2 to 29.4)% of mechanical breaths were autotriggered with the impedance system, there were no autotriggered breaths using the flow/volume system (p < 0.01). The rate of trigger failures was not significantly different with the two systems, at 1.2 (0 to 4.4)% (impedance) versus 3.1 (0 to 6.4)% (flow/volume). Minute ventilation was smaller with the impedance system (p < 0.001), because of the larger number of breaths triggered late in inspiration or during expiration. We conclude that the flow/volume-triggered system is less prone to autotriggering and has a shorter and more consistent response time than the impedance-triggered system. The impedance-triggered system is more susceptible to artifacts and chest wall distortion.

The following is a case report of a 1-month-old patient who developed adverse hemodynamic sequelae during the use of nitric oxide (NO) in the postoperative period for pulmonary hypertension after correction of total anomalous pulmonary venous return. At the time of diagnosis, the patient had evidence of systemic right ventricular pressures estimated by continuous-wave Doppler. He was sedated and paralyzed for hyperventilation in preparation for surgery and underwent pulmonary vein confluence to left atrial anastomosis. Postoperative pulmonary hypertension was managed by hyperventilation, sedation, and paralysis until a sudden onset of systemic-level pulmonary pressure required NO therapy. Satisfactory results were obtained in minutes, but a rebound pulmonary hypertension occurred with concomitant systemic hypertension and no radiographic changes. We suspected left atrial hypertension secondary to a sudden increase in pulmonary blood flow to an noncompliant left ventricle. Discontinuation of NO resulted in stabilization of the hemodynamic profile of the patient and he continued to be managed with paralysis, hyperventilation, and sedation. Based on this experience we suggest that NO should be used with caution in patients with obstructive lesions at the atrial level prior to surgery (mitral valve stenosis and cor triatriatum) or in patients with a poorly compliant left ventricle (cardiomyopathy and left ventricular dysfunction). These entities are unable to tolerate a sudden increase in pulmonary blood return thus creating paradoxical pulmonary hypertension.

OBJECTIVE Temporary pacing wires have been associated with serious postoperative complications. Recommendations for their routine use after open heart surgery are decades old, and may not reflect current surgical techniques and outcomes. METHODS The electronic web-enabled medical records of all patients undergoing congenital cardiac surgery from February, 2002, through December, 2005, were reviewed, excluding patients undergoing implantation of pacemakers as a primary procedure, or those undergoing ligation of a patent arterial duct. RESULTS There were 1193 surgical procedures performed, 1041 with cardiopulmonary bypass. Median age of the patients was 5.8 months, with a range from 0 days to 54 years, weighing 6.2 kilograms, with a range from 1 to 114 kilograms. Mortality prior to discharge was 2.5%, and median postoperative stay was 6 days. No deaths were attributed to arrhythmias. Temporary pacing wires were placed 14 times (1.2%). Indications for placement included sinus nodal dysfunction in 8 patients, preoperative in 4 and intraoperative in 4, high degree atrioventricular block in 4 patients, and intraoperative atrial flutter in 2 patients. Of these patients, 4 (0.3%) eventually underwent permanent implantation of a pacemaker, 2 for persistent sinus nodal dysfunction, and 2 for persistent atrioventricular block. Postoperative junctional ectopic tachycardia requiring antiarrhythmic therapy occurred in 9 patients (0.8%). All recovered without incident, and none were treated with temporary pacing. CONCLUSIONS The diminished risk of unexpected postoperative arrhythmias in the current era alleviates the necessity for routine placement of temporary pacing wires. Those institutions with experienced surgical and cardiac critical care teams may be able to predict the need for temporary pacing wires preoperatively or intraoperatively.

A goal-directed therapy algorithm based on serial lactate values obtained from a point-of-care testing device was utilized in an attempt to reduce the mortality of patients after congenital heart surgery. Prospective study of patients undergoing surgery utilizing a goal-directed therapy algorithm in the postoperative period. The results of this group are compared with a historical cohort. Operative risk was determined using the RACHS-1 scoring system. A 12-bed cardiac intensive care unit (ICU) in a pediatric hospital. Patients undergoing surgery from July 2001 through September 2003 (group B, n=710) were compared to cohorts from June 1995 through June 2001 (group A, n=1,656). Group B patients were smaller and younger (median weight 6.2 vs 8 kg, p

To ascertain possible mechanisms implicated in the development of transient episodes of hypoxemia (oxygen saturation85%) frequently observed in preterm infants undergoing mechanical ventilation, even after the acute phase of respiratory failure has passed.Tidal flow, airway and esophageal pressure, and oxygen saturation were continuously recorded in 10 infants (mean +/- SD, birth weight 733 +/- 149 gm, gestational age 25.5 +/- 2.2 weeks, age 26.3 +/- 11.9 days) who had repeated episodes of hypoxemia without any evident cause. Measurements of minute ventilation (VE) inspiratory compliance (Ci), and inspiratory resistance (Ri) were compared before and during episodes of hypoxemia.All episodes of hypoxemia were preceded by an active exhalation that produced a mean decrease in end-expiratory lung volume of 6.4 +/- 2.8 ml/kg. The reduction in lung volume was immediately followed by a sudden decrease in tidal flow and volume, despite continuation of mechanical ventilation at the same rate and peak pressure. The resulting hypoventilation was associated with a drop in Ci to approximately one half and an increase in Ri to more than double the baseline values. Approximately 30 seconds after the beginning of hypoventilation, the arterial oxygen saturation reached a hypoxemic level (oxygen saturation85%)Most hypoxemic episodes were triggered by an expiratory effort that produced a large decrease in lung volume. This reduction in lung volume probably leads to closure of small airways and the development of intrapulmonary shunts, which would explain the rapid development of hypoxemia.

Alveolar capillary dysplasia with misalignment of pulmonary veins (ACD/MPV) is a rare, neonatally lethal developmental disorder of the lung with defining histologic abnormalities typically associated with multiple congenital anomalies (MCA). Using array CGH analysis, we have identified six overlapping microdeletions encompassing the FOX transcription factor gene cluster in chromosome 16q24.1q24.2 in patients with ACD/MPV and MCA. Subsequently, we have identified four different heterozygous mutations (frameshift, nonsense, and no-stop) in the candidate FOXF1 gene in unrelated patients with sporadic ACD/MPV and MCA. Custom-designed, high-resolution microarray analysis of additional ACD/MPV samples revealed one microdeletion harboring FOXF1 and two distinct microdeletions upstream of FOXF1, implicating a position effect. DNA sequence analysis revealed that in six of nine deletions, both breakpoints occurred in the portions of Alu elements showing eight to 43 base pairs of perfect microhomology, suggesting replication error Microhomology-Mediated Break-Induced Replication (MMBIR)/Fork Stalling and Template Switching (FoSTeS) as a mechanism of their formation. In contrast to the association of point mutations in FOXF1 with bowel malrotation, microdeletions of FOXF1 were associated with hypoplastic left heart syndrome and gastrointestinal atresias, probably due to haploinsufficiency for the neighboring FOXC2 and FOXL1 genes. These differences reveal the phenotypic consequences of gene alterations in cis.