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Truncus arteriosus with interrupted aortic arch (TA-IAA) is a rare congenital heart defect with historically poor outcomes. Contemporary multicenter data are limited.A retrospective cohort study of children who underwent repair of TA-IAA between 2009 and 2016 at 12 tertiary care referral centers within the United States was performed. Major adverse cardiac events (MACE) were defined as postoperative extracorporeal membrane oxygenation, cardiopulmonary resuscitation, or operative mortality. TA-IAA patients were compared with TA patients who underwent repair during the study period from the same institutions.We reviewed 35 patients with TA-IAA. MACE occurred in 12 patients (34%). Improvement over time was observed during the study period with 11 events (92%) occurring in the first half of the study period (P = .03). Factors associated with MACE included moderate or severe truncal valve insufficiency (P.01), concomitant truncal valve repair (P = .04), and longer cardiopulmonary bypass duration (P = .02). In comparison with 216 patients who underwent TA repair, patients with TA-IAA had a higher rate of MACE, but this finding was not statistically significant (34% vs 20%, respectively; P = .07). Additionally no differences between TA-IAA and TA groups were observed for unplanned reoperations (14% vs 22%, respectively; P = .3), hospital length of stay (24 vs 23 days, P = .65), or late deaths (7% vs 7%, P = 1.00).In this contemporary, multicenter cohort the rate of MACE after repair of TA-IAA was high but improved during the study period. Early childhood outcomes of patients with TA-IAA were similar to those with TA.

OBJECTIVES To evaluate neurodevelopmental and mental disorders after PICU hospitalization in children requiring invasive mechanical ventilation for severe respiratory illness. DESIGN Retrospective longitudinal observational cohort. SETTING Texas Medicaid Analytic eXtract data from 1999 to 2012. PATIENTS Texas Medicaid-enrolled children greater than or equal to 28 days old to less than 18 years old hospitalized for a primary respiratory illness, without major chronic conditions predictive of abnormal neurodevelopment. INTERVENTIONS We examined rates of International Classification of Diseases, 9th revision-coded mental disorder diagnoses and psychotropic medication use following discharge among children requiring invasive mechanical ventilation for severe respiratory illness, compared with general hospital patients propensity score matched on sociodemographic and clinical characteristics prior to admission. Children admitted to the PICU for respiratory illness not necessitating invasive mechanical ventilation were also compared with matched general hospital patients as a negative control exposure. MEASUREMENTS AND MAIN RESULTS Of 115,335 eligible children, 1,351 required invasive mechanical ventilation and were matched to 6,755 general hospital patients. Compared with general hospital patients, children requiring invasive mechanical ventilation had increased mental disorder diagnoses (hazard ratio, 1.43 [95% CI, 1.26-1.64]; p < 0.0001) and psychotropic medication use (hazard ratio, 1.67 [1.34-2.08]; p < 0.0001) following discharge. Seven-thousand seven-hundred eighty children admitted to the PICU without invasive mechanical ventilation were matched to 38,900 general hospital patients and had increased mental disorder diagnoses (hazard ratio, 1.08 [1.02-1.15]; p = 0.01) and psychotropic medication use (hazard ratio, 1.11 [1.00-1.22]; p = 0.049). CONCLUSIONS Children without major comorbidity requiring invasive mechanical ventilation for severe respiratory illness had a 43% higher incidence of subsequent mental disorder diagnoses and a 67% higher incidence of psychotropic medication use. Both increases were substantially higher than in PICU patients with respiratory illness not necessitating invasive mechanical ventilation. Invasive mechanical ventilation is a life-saving therapy, and its application is interwoven with underlying health, illness severity, and PICU management decisions. Further research is required to determine which factors related to invasive mechanical ventilation and severe respiratory illness are associated with abnormal neurodevelopment. Given the increased risk in these children, identification of strategies for prevention, neurodevelopmental surveillance, and intervention after discharge may be warranted.

Fontan circuit thrombosis is a significant cause of early postoperative morbidity and mortality. Thrombosis incidence and relationship to thromboprophylaxis choice and timing of initiation are not well established. We sought to evaluate the incidence of Fontan circuit thrombosis in the first 30 postoperative days and its relationship to thromboprophylaxis choice and timing. Patients undergoing Fontan surgery, 2006-2016, were reviewed. Fontan circuit thrombosis was defined by sonographic detection of intracardiac or deep venous thrombi. Logistic regression was used to assess relationships between thromboprophylaxis characteristics and thrombosis. One hundred ninety-two patients underwent Fontan. Fontan thrombosis occurred in 19 (10%) patients. 54% were started on aspirin, 27% coumadin, 4% heparin, and 7% none. There was no relationship between thrombosis and baseline anatomy, Fontan type or fenestration. Median time to thromboprophylaxis initiation was 4 days (interquartile range 2-6). Patients not started on thromboprophylaxis had 44.8 times the odds of thrombosis as those on thromboprophylaxis (confidence interval 6.4-311.7, P0.01); no children starting thromboprophylaxis before postoperative day 2 developed thromboses. For every day that thromboprophylaxis was delayed, odds of thrombosis increased by 30% (odds ratio 1.3; CI 1.1-1.6, P0.01). There was no difference in the odds of thrombosis between children taking aspirin vs other thromboprophylaxis types. Odds of early postoperative Fontan circuit thrombosis are increased in patients in whom thromboprophylaxis is delayed beyond the second postoperative day, with no difference in the odds of thrombosis between patients initiated on aspirin vs other thromboprophylaxis. Early aspirin institution post Fontan is recommended to reduce morbidity. Ultra-mini-Abstract: Odds of early postoperative Fontan circuit thrombosis are increased in patients in whom thromboprophylaxis is delayed beyond the second postoperative day, with no difference in the odds of thrombosis between patients initiated on aspirin vs other thromboprophylaxis. Early aspirin institution post Fontan is recommended to reduce morbidity and resource utilization.

Truncal valve management in patients with truncus arteriosus is a clinical challenge, and indications for truncal valve intervention have not been defined. We sought to evaluate truncal valve dysfunction and primary valve intervention in patients with truncus arteriosus and determine risk factors for later truncal valve intervention. We conducted a retrospective cohort study of children who underwent truncus arteriosus repair at 15 centers between 2009 and 2016. Multivariable competing risk analysis was performed to determine risk factors for later truncal valve intervention. We reviewed 252 patients. Forty-two patients (17%) underwent truncal valve intervention during their initial surgery. Postoperative extracorporeal support, CPR, and operative mortality for patients who underwent truncal valve interventions were statistically similar to the rest of the cohort. Truncal valve interventions were performed in 5 of 64 patients with mild insufficiency; 5 of 16 patients with mild-to-moderate insufficiency; 17 of 35 patients with moderate insufficiency; 5 of 9 patients with moderate-to-severe insufficiency; and all 10 patients with severe insufficiency. Twenty patients (8%) underwent later truncal valve intervention, five of whom had no truncal valve intervention during initial surgical repair. Multivariable analysis revealed truncal valve intervention during initial repair (HR 11.5; 95% CI 2.5, 53.2) and moderate or greater truncal insufficiency prior to initial repair (HR 4.0; 95% CI 1.1, 14.5) to be independently associated with later truncal valve intervention. In conclusion, in a multicenter cohort of children with truncus arteriosus, 17% had truncal valve intervention during initial surgical repair. For patients in whom variable truncal valve insufficiency is present and primary intervention was not performed, late interventions were uncommon. Conservative surgical approach to truncal valve management may be justifiable.

Background Literature describing morbidity and mortality after truncus arteriosus repair is predominated by single-center reports. We created and analyzed a multicenter dataset to identify risk factors for late mortality and right ventricle-to-pulmonary artery (RV-PA) conduit reintervention for this patient population. Methods We retrospectively collected data on children who underwent repair of truncus arteriosus without concomitant arch obstruction at 15 centers between 2009 and 2016. Cox regression survival analysis was conducted to determine risk factors for late mortality, defined as death occurring after hospital discharge and greater than 30 days after operation. Probability of any RV-PA conduit reintervention was analyzed over time using Fine-Gray modeling. Results We reviewed 216 patients with median follow-up of 2.9 years (range, 0.1 to 8.8). Operative mortality occurred in 15 patients (7%). Of the 201 survivors there were 14 (7%) late deaths. DiGeorge syndrome (hazard ratio [HR], 5.4; 95% confidence interval [CI], 1.6 to 17.8) and need for postoperative tracheostomy (HR, 5.9; 95% CI, 1.8 to 19.4) were identified as independent risk factors for late mortality. At least one RV-PA conduit catheterization or surgical reintervention was performed in 109 patients (median time to reintervention, 23 months; range, 0.3 to 93). Risk factors for reintervention included use of pulmonary or aortic homografts versus Contegra (Medtronic, Inc, Minneapolis, MN) bovine jugular vein conduits (HR, 1.9; 95% CI, 1.2 to 3.1) and smaller conduit size (HR per mm/m2, 1.05; 95% CI, 1.03 to 1.08). Conclusions In a multicenter dataset DiGeorge syndrome and need for tracheostomy postoperatively were found to be independent risk factors for late mortality after repair of truncus arteriosus, whereas risk of conduit reintervention was independently influenced by both initial conduit type and size.

Truncal valve management in patients with truncus arteriosus is a clinical challenge, and indications for truncal valve intervention have not been defined. We sought to evaluate truncal valve dysfunction and primary valve intervention in patients with truncus arteriosus and determine risk factors for later truncal valve intervention. We conducted a retrospective cohort study of children who underwent truncus arteriosus repair at 15 centers between 2009 and 2016. Multivariable competing risk analysis was performed to determine risk factors for later truncal valve intervention. We reviewed 252 patients. Forty-two patients (17%) underwent truncal valve intervention during their initial surgery. Postoperative extracorporeal support, CPR, and operative mortality for patients who underwent truncal valve interventions were statistically similar to the rest of the cohort. Truncal valve interventions were performed in 5 of 64 patients with mild insufficiency; 5 of 16 patients with mild-to-moderate insufficiency; 17 of 35 patients with moderate insufficiency; 5 of 9 patients with moderate-to-severe insufficiency; and all 10 patients with severe insufficiency. Twenty patients (8%) underwent later truncal valve intervention, five of whom had no truncal valve intervention during initial surgical repair. Multivariable analysis revealed truncal valve intervention during initial repair (HR 11.5; 95% CI 2.5, 53.2) and moderate or greater truncal insufficiency prior to initial repair (HR 4.0; 95% CI 1.1, 14.5) to be independently associated with later truncal valve intervention. In conclusion, in a multicenter cohort of children with truncus arteriosus, 17% had truncal valve intervention during initial surgical repair. For patients in whom variable truncal valve insufficiency is present and primary intervention was not performed, late interventions were uncommon. Conservative surgical approach to truncal valve management may be justifiable.

Background Elevated pulmonary vascular resistance (PVR) is common following repair of truncus arteriosus. Inhaled nitric oxide (iNO) is an effective yet costly therapy that is frequently implemented postoperatively to manage elevated PVR. Objectives We aimed to describe practice patterns of iNO use in a multicenter cohort of patients who underwent repair of truncus arteriosus, a lesion in which recovery is often complicated by elevated PVR. We also sought to identify patient and center factors that were more commonly associated with the use of iNO in the postoperative period. Design Retrospective cohort study. Setting 15 tertiary care pediatric referral centers. Patients All infants who underwent definitive repair of truncus arteriosus without aortic arch obstruction between 2009 and 2016. Interventions Descriptive statistics were used to demonstrate practice patterns of iNO use. Bivariate comparisons of characteristics of patients who did and did not receive iNO were performed, followed by multivariable mixed logistic regression analysis using backward elimination to identify independent predictors of iNO use. Main results We reviewed 216 patients who met inclusion criteria, of which 102 (46%) received iNO in the postoperative period: 69 (68%) had iNO started in the operating room and 33 (32%) had iNO initiated in the ICU. Median duration of iNO use was 4 days (range: 1-21 days). In multivariable mixed logistic regression analysis, use of deep hypothermic circulatory arrest (odds ratio: 3.2; 95% confidence interval: 1.2, 8.4) and center (analyzed as a random effect, p = .02) were independently associated with iNO use. Conclusions In this contemporary multicenter study, nearly half of patients who underwent repair of truncus arteriosus received iNO postoperatively. Use of iNO was more dependent on individual center practice rather than patient characteristics. The study suggests a need for collaborative quality initiatives to determine optimal criteria for utilization of this important but expensive therapy.

Objective We sought to describe characteristics and operative outcomes of children who underwent repair of truncus arteriosus and identify risk factors for the occurrence of major adverse cardiac events (MACE) in the immediate postoperative period in a contemporary multicenter cohort. Methods We conducted a retrospective review of children who underwent repair of truncus arteriosus between 2009 and 2016 at 15 centers within the United States. Patients with associated interrupted or obstructed aortic arch were excluded. MACE was defined as the need for postoperative extracorporeal membrane oxygenation, cardiopulmonary resuscitation, or operative mortality. Risk factors for MACE were identified using multivariable logistic regression analysis and reported as odds ratios (ORs) with 95% confidence intervals (CIs). Results We reviewed 216 patients. MACE occurred in 44 patients (20%) and did not vary significantly over time. Twenty-two patients (10%) received postoperative extracorporeal membrane oxygenation, 26 (12%) received cardiopulmonary resuscitation, and 15 (7%) suffered operative mortality. With multivariable logistic regression analysis (which included adjustment for center effect), factors independently associated with MACE were failure to diagnose truncus arteriosus before discharge from the nursery (OR, 3.1; 95% CI, 1.3-7.4), cardiopulmonary bypass duration >150 minutes (OR, 3.5; 95% CI, 1.5-8.5), and right ventricle-to-pulmonary artery conduit diameter >50 mm/m2 (OR, 4.7; 95% CI, 2.0-11.1). Conclusions In a contemporary multicenter analysis, 20% of children who underwent repair of truncus arteriosus experienced MACE. Early diagnosis, shorter duration of cardiopulmonary bypass, and use of smaller diameter right ventricle-to-pulmonary artery conduits represent potentially modifiable factors that could decrease morbidity and mortality in this fragile patient population.

Nitric oxide (NO)-associated pulmonary edema is rarely reported in children; in adults, it is often associated with left-sided heart failure. We report a case series of children with NO-associated pulmonary edema, which was defined as new multilobar alveolar infiltrates and worsening hypoxemia within 24 h of initiation or escalation of NO and radiologic or clinical improvement after NO discontinuation. We identified six patients (0.4-4 years old) with ten episodes of NO-associated pulmonary edema. Diagnoses included atrioventricular canal defect with mitral valve disease (n = 2), pulmonary atresia and major aorta-pulmonary collateral arteries (n = 2), total anomalous pulmonary venous return (n = 1), and pulmonary veno-occlusive disease (n = 1). All patients had evidence of pulmonary venous hypertension, and two had mitral valve disease resulting in clinical evidence of left-sided heart failure. Pulmonary edema improved or resolved within 24 h of discontinuing NO. At cardiac catheterization, mean left atrial pressure was15 mmHg in three of three patients (none with mitral valve disease), whereas pulmonary artery occlusion pressure was15 mmHg in two of five patients. In conclusion, we describe six young children with NO-associated pulmonary edema and pulmonary venous hypertension. Only two of these children had left-sided heart failure: Left atrial pressure as well as pulmonary artery occlusion pressure may not be helpful in identifying children at risk for NO-associated pulmonary edema.

Background Pulmonary hypertension causes increased morbidity and mortality in adults after heart transplantation. The effect of markedly elevated pulmonary vascular resistance (PVR) on post-transplant outcomes in children has not been well described. Methods Outcomes were compared in a retrospective study between 58 children with an elevated PVR index (PVRI) ≥ 6 U/m 2 and 205 children with a PVRI 2 . Patients who did and did not respond to acute vasodilator testing and patients who underwent transplant before (pre-1995) and after (post-1995) the availability of inhaled nitric oxide (iNO) were compared. Results The pre-transplant diagnoses, and cardiopulmonary bypass and donor ischemic times were similar between the high and low PVRI groups. High PVRI patients were older at transplant (12 ± 6.2 vs 8 ± 7.1 years, p = 0.002 ). The post-transplant inotrope score was higher in the high PVRI group (12 ± 12 vs 2 ± 2, p = 0.0001) and 1-year survival was worse (76% vs 81%, p = 0.03). The PVRI fell to 2 with acute vasodilator testing in 21 of 49 (42%) high PVRI patients. RV failure occurred in 4 (19%) of the responders and in 14 (50%) of the non-responders ( p = 0.037). One responder (5%) and 4 non-responders (14%) died of RV failure. In the period after 1995, the year iNO became clinically available, the select group of high PVRI patients who received iNO preemptively had a lower incidence of post-transplant RV failure than the group that did not receive preemptive iNO (13% vs 54%, p = 0.04). Conclusions Pre-transplant vasodilator testing identified patients at higher risk for RV failure. Patients who did not respond to vasodilator testing had an increased incidence of RV failure and death from RV failure. Preemptive use of iNO was associated with a decreased incidence of RV failure.

To evaluate the effect of inhaled nitric oxide (INO) in pulmonary hypertension of the newborn (PH) in a single center over 5 years using gentle ventilation (GV), without hyperventilation or induced alkalosis.Data from 229 consecutive infants with PH of varied etiology treated with INO and GV, and from 67 infants with meconium aspiration syndrome (MAS) and primary PH (PPHN) treated with GV alone were reviewed over a 5-year period (86% outborn). INO was initiated at 25 ppm when PH and severe hypoxemia persisted despite maximal optimal ventilation. Hyperventilation or systemic alkalosis were not attempted.Mean duration of ventilation was 9.9 +/- 14 days (median 6.5 days). Average mean airway pressure (MAP) dropped from 17.7 +/- 4.3 cm H(2)O at the referral hospital to 13.2 +/- 2.5 cm H(2)O (p0.001) following admission to our unit using conventional settings and GV, before starting INO. Mean oxygenation index (OI) dropped from 46.8 +/- 24.5 to 22.7 +/- 21.4 within 24 hours of INO therapy (p0.001). Infants with higher baseline pH and lower baseline OI responded better to INO (p0.02). Overall survival was 72%. Patients with MAS and PPHN had the best response, 92% survived and there was a 46% reduction in need for extracorporeal membrane oxygenation (ECMO) compared to historical pre-INO period controls (23.9% vs. 12.8%, p0.01). In the infants treated with GV alone, the MAP dropped from 17.2 +/- 4.3 cm H2O at the referral hospital to 12.6+/-2.4 after GV was started in our unit.We conclude that INO is an effective and well-tolerated therapy for PH in infants receiving GV.

ObjectivesTo determine whether peripheral veins can be detected by ultrasound (US) and to determine vein characteristics, as measured by US, that are associated with successful peripheral venous (PV) catheterization in young children. MethodsThe authors conducted an observational study in the pediatric emergency department (ED), with a convenience sample of children younger than 7 years. They evaluated attempts at PV catheterization in two groups on the basis of the visibility and palpability of the patients' veins: 1) clinically apparent (visible or palpable) and 2) not clinically apparent (nonvisible and nonpalpable). The authors obtained sonographic measurements in a transverse view (vertical diameter, circumference, and area) and in a longitudinal view (maximal uninterrupted length). Practitioners blinded to the US images then attempted to catheterize veins in the usual manner. The proportion of clinically apparent veins and the proportion of veins that were successfully catheterized that were identified by US were assessed, and the association between ultrasonographic vein measurements and success at catheterization, controlling for possible confounders, was determined. ResultsThe authors assessed 120 attempts (90 clinically apparent and 30 not clinically apparent) at PV catheterization in 83 patients. US detected all 90 clinically apparent veins, and cannulation success rate was 62/90 (69%). In the not clinically apparent vein group, the rate of success was only 3/30 (10%), and US detected all successfully catheterized veins. In no instance was cannulation successful when the vein was not detected by US. Maximal vein length in longitudinal view was an independent predictor of cannulation success in multivariate analysis. ConclusionsUltrasound appears to be capable of detecting peripheral veins in children younger than 7 years of age, with lack of US vein visualization likely leading to unsuccessful PV placement. Greater vein length visualization may be a useful predictor of successful PV catheterization.

In newborns, inhaled nitric oxide (NO) has been shown to ameliorate increased pulmonary vascular resistance (PVR) precipitated by hypoxia. The role of endogenous NO production in this response is not clear. The contribution of endogenous NO to resting PVR in normoxic newborns also has not been well studied. The authors used an isolated, in situ, neonatal piglet lung-perfusion model, devoid of systemic detractors in which endogenous NO could be selectively inhibited, to determine whether (1) endogenous NO plays a role in the maintenance of PVR with normoxia, (2) endogenous NO plays a role in the response to hypoxia, and (c) inhaled NO can reverse changes induced by inhibition of endogenous NO.Sixteen neonatal piglets underwent occlusive tracheostomy and pressure-cycled ventilation. After heparinization and ligation of the ductus arteriosus, left atrial and pulmonary arterial cannulation were performed, without ischemia, via a median sternotomy. The aorta was ligated, and lung perfusion was set at 80 mL/kg/min via an extracorporeal membrane oxygenation circuit. Hematocrit (40% to 45%), pH (7.37 to 7.44), Pco2 (35 to 40 mm Hg), and peak inspiratory pressures (20 mm Hg) were constant. Pulmonary artery pressure (PPA), left atrial pressure (PLA), and circuit flow (QPA) were recorded continuously. PVR calculated as follows: PVR[(dynes x seconds x cm(-5)) x 1,000] = [(PPA-PLA/(QPA x 1,000/60)] x 1,332. The experimental animals were ventilated with normoxic gas (FIO2, 0.21), followed by hypoxic gas (FIO2, 0.07), returned to normoxia, and then divided into two groups of eight animals each. One group remained normoxemic (FIO2, 0.21; SPA02, 100%) while the other group was made hypoxemic by ventilation with hypoxic gas (FIO2, 0.07; SPA02, 50%). Endogenous NO was suppressed with L-arginine-N-omega methyl ester (L-NAME) at 40 mg/kg in both groups. Inhaled NO was given at 40 ppm in both groups. Analysis of variance for repeated measures was used to test for statistical significance.Baseline normoxic PVR (3,403 +/- 1,169) was increased significantly by hypoxia (6,524 +/- 1,018, P.01) and was fully resorted to baseline by normoxia (3,497 +/- 1,079; P = NS). In normoxic animals, inhibition of endogenous NO production by L-NAME increased PVR to levels similar to those seen during hypoxic stress (6,345 +/- 1,441, P.01). Replacement of endogenous NO by inhaled NO reversed PVR to normoxic baseline values (3,986 +/- 1,363, P = NS). In hypoxic animals, inhibition of endogenous NO production by L-NAME also increased PVR from hypoxic baseline (9,655 +/- 1,642, P.01). Replacement of endogenous NO by inhaled NO reversed PVR to hypoxic baseline (6,450 +/- 1,796, P = NS).In this piglet model, endogenous NO is important in the regulation of pulmonary vascular tone during both normoxia and hypoxia. Inhaled NO completely reversed the elevations in PVR caused by inhibition of endogenous NO and may normalize PVR in diseases in which the production of endogenous NO is compromised.

It has been suggested that inhaled nitric oxide gas may be beneficial after lung transplantation, because endogenous levels of pulmonary nitric oxide decline rapidly after reperfusion. However theoretical concerns remain about the formation of highly toxic oxidants during the quenching of nitric oxide by superoxide. To determine whether distal stimulation of the nitric oxide–cyclic guanosine monophosphate pathway at the level of cyclic guanosine monophosphate might confer the beneficial vascular effects of nitric oxide without its potential toxicities, we studied an orthotopic rat left lung transplant model. In this model, hemodynamic and survival measurements can be obtained independent of the native right lung. Lungs were preserved for 6 hours at 4°C in Euro-Collins solution alone (control, n = 6) or supplemented with the cyclic guanosine monophosphate analog, 8-(4-chlorophenylthio)-guanosine–3′,5′-cyclic guanosine monophosphate (cGMP, n = 4). In additional experiments in which lungs were preserved with Euro-Collins solution alone, inhaled nitric oxide was administered during reperfusion (NO, n = 12). Thirty minutes after transplantation and ligation of the native right pulmonary artery, pulmonary vascular resistance, arterial oxygenation, graft neutrophil infiltration (myeloperoxidase activity), and recipient survival were evaluated. Cyclic guanosine monophosphate decreased pulmonary vascular resistance (1.1 ± 0.2 vs 12.1 ± 6.3 mm Hg/ml/min, p < 0.05), improved oxygen tension (369 ± 56 vs 82.8 ± 48 mm Hg, p < 0.05), reduced myeloperoxidase activity (1.7 ± 0.3 vs 3.1 ± 0.9 ΔDAbs 460 nm/min, p < 0.05), and improved recipient survival (100% vs 0%, p < 0.005) compared with Euro-Collins solution alone (control group). Animals receiving inhaled nitric oxide during reperfusion did not differ from control animals with respect to any of these parameters. These data suggest that distal stimulation of the nitric oxide–cyclic guanosine monophosphate pathway at the level of cyclic guanosine monophosphate has a protective effect that is not seen with inhaled nitric oxide in the immediate pulmonary reperfusion period. (J THORAC CARDIOVASC SURG 1995;110:1434-41)

Withdrawal syndromes following administration of sedative and analgesic infusions represent a significant morbidity that is described increasingly in the pediatric critical care literature. However, there are few descriptions of pentobarbital withdrawal symptoms and their treatment in the pediatric population. We describe an infant receiving multiple sedative and analgesic medications, including pentobarbital, who was resistant to our institution's standard weaning protocol, but whose severe withdrawal symptoms responded dramatically to phenobarbital loading and maintenance.

This report describes a newborn with transposition of the great arteries who underwent a Blalock-Taussig shunt with transient improvement in oxygenation, but required emergent insertion of a central shunt later the same day due to progressive hypoxia and cardiac arrest. Two hours after central shunt insertion, sudden episodes of hypoxia and hypotension developed that were resistant to all pharmacologic therapy. Inhaled nitric oxide (25 ppm) was then administered with dramatic improvement in oxygenation and hemodynamics within minutes. The patient's condition stabilized after these measures, and nitric oxide therapy was discontinued after 2 days.

Background . Pulmonary vascular resistance is often elevated in patients with congestive heart failure, and in those undergoing left ventricular assist device (LVAD) insertion, it may precipitate right ventricular failure and hemodynamic collapse. Because the effectiveness of inotropic and vasodilatory agents is limited by systemic effects, right ventricular assist devices are often required. Inhaled nitric oxide (NO) is an effective, specific pulmonary vasodilator that has been used successfully in the management of pulmonary hypertension. Methods . Eleven of 23 patients undergoing LVAD insertion met criteria for elevated pulmonary vascular resistance on weaning from cardiopulmonary bypass (mean pulmonary artery pressure >25 mm Hg and LVAD flow rate −1 · m −2 ) and were randomized to receive either inhaled NO at 20 ppm (n = 6) or nitrogen (n = 5). Patients not manifesting a clinical response after 15 minutes were given the alternative agent. Results . Hemodynamics for the group at randomization were as follows: mean arterial pressure, 72 ± 6 mm Hg; mean pulmonary artery pressure, 32 ± 4 mm Hg; and LVAD flow, 2.0 ± 0.3 L · min −1 · m −2 . Patients receiving inhaled NO exhibited significant reductions in mean pulmonary artery pressure and increases in LVAD flow, whereas none of the patients receiving nitrogen showed hemodynamic improvement. Further, when the nitrogen group was subsequently given inhaled NO, significant hemodynamic improvements ensued. There were no significant changes in mean arterial pressure in either group. Conclusions . Inhaled NO induces significant reductions in mean pulmonary artery pressure and increases in LVAD flow in LVAD recipients with elevated pulmonary vascular resistance. We conclude that inhaled NO is a useful intraoperative adjunct in patients undergoing LVAD insertion in whom pulmonary hypertension limits device filling and output.

Background: Reports of pulmonary edema complicating inhaled nitric oxide therapy in patients with chronic heart failure and pulmonary hypertension have raised the concern that inhaled nitric oxide may have negative inotropic effects. Methods and results: We investigated the effect of multiple doses of inhaled nitric oxide (20, 40 and 80 ppm) on left ventricular contractile state in 10 open-chest pigs. Pressure-volume loops were generated during transient preload reduction to determine the end-systolic pressure-volume relationship and the stroke work-end-diastolic volume relation. Inhaled nitric oxide had no effect on systemic vascular resistance, cardiac output, end-systolic pressure-volume relationship or stroke work-end-diastolic volume relation under normal conditions. After induction of pulmonary hypertension (intravenous thromboxane A2 analog), inhalation of nitric oxide (80 ppm) resulted in a reduction in pulmonary vascular resistance (mean ± standard error of the mean) from 10.4 ± 3 to 6.5 ± 2 Wood units (p < 0.001) and in pulmonary artery pressure from 44 ± 4 to 33 ± 4 mm Hg (p < 0.05). Left ventricular end-diastolic volume rose from 53 ± 9 ml to 57 ± 10 ml (p = 0.02). No statistically significant change in cardiac output or systemic vascular resistance was observed. Inhaled nitric oxide had no effect on end-systolic pressure-volume relationship or stroke work-end-diastolic volume relation. Conclusions: In a porcine model of pulmonary hypertension, inhaled nitric oxide does not impair left ventricular contractile function. Therefore the cause of pulmonary edema observed in some patients receiving inhaled nitric oxide is not due to a negative inotropic action of this therapy. (J Thorac Cardiovasc Surg 1997;114:461-6)

Inhaled nitric oxide (NO) is effective as a selective pulmonary vasodilator, but its effects on uninjured lungs subjected to normoxia and hypoxia have not been fully studied. The authors sought the response of pulmonary vascular resistance (PVR) to inhaled NO in piglet lungs devoid of ischemic injury in a model of reversible pulmonary hypertension. If the changes were dose-responsive, the authors asked whether the PVR changes were related to normoxia or hypoxia, and hypothesized that the change would be more pronounced for hypoxia than normoxia. In situ isolated piglet lungs were prepared by occlusive tracheostomy and ligation of the ductus arteriosus and aorta. Cannulae positioned in the left atrium and pulmonary artery were connected to a standard extracorporeal membrane oxygenation (ECMO) circuit, and flow was increased to approximate cardiac output. After stabilization, piglets (aged 5 to 14 days, weighing 3.2 to 6.4 kg) were divided into two groups of four each: normoxic (Fio 2 0.30, normal PVR) and hypoxic (Fio 2 0.07, increased PVR). NO was administered at 10 to 80 parts per million (ppm) in increments of 10 ppm, for 5 minutes at each concentration, with a return to baseline before each new dose. Flow, pulmonary arterial (PA) and left atrial (LA) pressures were continuously monitored, from which PVR was calculated (PVR = [P PA − P LA ]/flow) and expressed as logΔPVR. Data were analyzed statistically by repeated measures of analysis of variance, comparing logΔPVR to baseline at each dose of NO, and comparing logΔPVR for normoxic and hypoxic lungs at each dose of NO. The authors found: (1) NO significantly decreased PVR at all doses in both normoxic and hypoxic piglet lungs ( P P

Recently, we used esmolol, a short-acting, β 1 selective blocker to treat three children with post-operative rebounded hypertension. Because of this agent's reliable hypotensive effect, speed of onset, short half-like, and lack of significant side-effects, we anticipated that esmolol would be effective in the treatment of severe postcoarctation repair hypertension