Physiological effects of noninvasive positive ventilation during acute moderate hypercapnic respiratory insufficiency in children.

INTRODUCTION: A prospective physiological study was performed in 12 paediatric patients with acute moderate hypercapnic respiratory insufficiency to assess the ability of noninvasive positive pressure ventilation (NPPV) to unload the respiratory muscles and improve gas exchange. MATERIALS AND METHODS: Breathing pattern, gas exchange, and inspiratory muscle effort were measured during spontaneous breathing and NPPV. RESULTS: NPPV was associated with a significant improvement in breathing pattern, gas exchange and respiratory muscle output. Tidal volume and minute ventilation increased by 33 and 17%, and oesophageal and diaphragmatic pressure time product decreased by 49 and 56%, respectively. This improvement in alveolar ventilation translated into a reduction in mean partial pressure in carbon dioxide from 48 to 40 mmHg (P = 0.01) and in respiratory rate from 48 to 41 breaths/min (P = 0.01). No difference between a clinical setting and a physiological setting of NPPV was observed. In conclusion, this study shows that NPPV is able to unload the respiratory muscles and improve clinical outcome in young patients admitted to the paediatric intensive care unit for acute moderate hypercapnic respiratory insufficiency.

Prophylactic endoscopic sclerotherapy of large esophagogastric varices in infants with biliary atresia.

BACKGROUND: Esophageal varices-related GI bleeding occurs frequently and early in life in children with biliary atresia and it may be life threatening. OBJECTIVE: We report the results of prophylactic sclerotherapy in 13 infants with biliary atresia and large varices. PATIENTS: Mean age was 13 months, mean weight was 8.2 kg, mean total serum bilirubin was 258 mumol/L, and mean prothrombin time was 78%. Esophageal varices were grade III (11 patients) or II (2 patients), with red signs in all infants and gastric varices in 12. None had GI bleeding. INTERVENTION: Sclerotherapy was performed with the patient under continuous intravenous octreotide therapy in 7 infants. RESULTS: In 8 children a complete or almost complete eradication of varices was obtained; none of these children bled later, 4 underwent liver transplantation, 3 are alive without liver transplantation, and 1 died of sepsis after 9 months awaiting liver transplantation. In 4 children a partial eradication was obtained and liver transplantation was performed. None of these children bled. One other child bled to death after 2 sessions of sclerotherapy. LIMITATIONS: Four ulcers and 2 stenoses occurred in 6 children with no octreotide versus no ulcer and 1 stenosis in 7 children receiving octreotide. CONCLUSION: These results (1) indicate that primary prevention of GI bleeding by sclerotherapy of esophageal varices is technically feasible and fairly effective in infants with biliary atresia and large varices, even in those with end-stage liver disease, (2) suggest that decreasing the risk of bleeding may allow liver transplantation under better conditions, and (3) further suggest that octreotide associated with sclerotherapy lowers the rate of complications.

Respiratory variations in aortic blood flow predict fluid responsiveness in ventilated children.

OBJECTIVE: To investigate whether respiratory variations in aortic blood flow velocity (DeltaVpeak ao), systolic arterial pressure (DeltaPS) and pulse pressure (DeltaPP) could accurately predict fluid responsiveness in ventilated children. DESIGN AND SETTING: Prospective study in a 18-bed pediatric intensive care unit. PATIENTS: Twenty-six children [median age 28.5 (16-44) months] with preserved left ventricular (LV) function. INTERVENTION: Standardized volume expansion (VE). MEASUREMENTS AND MAIN RESULTS: Analysis of aortic blood flow by transthoracic pulsed-Doppler allowed LV stroke volume measurement and on-line DeltaVpeak ao calculation. The VE-induced increase in LV stroke volume was >15% in 18 patients (responders) and <15% in 8 (non-responders). Before VE, the DeltaVpeak ao in responders was higher than that in non-responders [19% (12.1-26.3) vs. 9% (7.3-11.8), p=0.001], whereas DeltaPP and DeltaPS did not significantly differ between groups. The prediction of fluid responsiveness was higher with DeltaVpeak ao [ROC curve area 0.85 (95% IC 0.99-1.8), p=0.001] than with DeltaPS (0.64) or DeltaPP (0.59). The best cut-off for DeltaVpeak ao was 12%, with sensitivity, specificity, and positive and negative predictive values of 81.2%, 85.7%, 93% and 66.6%, respectively. A positive linear correlation was found between baseline DeltaVpeak ao and VE-induced gain in stroke volume (rho=0.68, p=0.001). CONCLUSIONS: While respiratory variations in aortic blood flow velocity measured by pulsed Doppler before VE accurately predict the effects of VE, DeltaPS and DeltaPP are of little value in ventilated children.

The transesophageal Doppler and hemodynamic effects of epidural anesthesia in infants anesthetized with sevoflurane and sufentanil.

BACKGROUND: It is thought that pediatric epidural anesthesia (EA) provides hemodynamic stability in children. However, when compared with information relating to adults, little is known about the hemodynamic effects of epidural EA on cardiac output (CO) in infants. METHODS: Using transesophageal Doppler to monitor CO, we prospectively studied 14 infants <10 kg who were scheduled for abdominal surgery. During sevoflurane general anesthesia, CO transesophageal Doppler monitoring was performed before and after lumbar EA with 0.75 mL/kg of 0.25% bupivacaine and 1:200,000 adrenaline. CO, arterial blood pressure, and heart rate were measured before and 5, 15, and 20 min after performance of EA. RESULTS: In patients anesthetized with sevoflurane and sufentanil, EA resulted in an increase in stroke volume by 29% (P < 0.0001) and a decrease in heart rate by 13% (P < 0.0001). EA also induced a significant decrease in systolic, diastolic, mean arterial blood pressure, and systemic vascular resistance by 11%, 18%, 15%, and 25%, respectively. Conversely, CO remained unchanged. CONCLUSIONS: The increase in stroke volume observed is probably explained by optimization of afterload because of the sympathetic blockade induced by EA. These results confirm that EA provides hemodynamic stability in infants weighing <10 kg and supports the use of EA in this pediatric population.

Nonketotic hyperglycemic coma in toddlers after unintentional methadone ingestion.

Methadone overdoses are increasing in parallel with the increased frequency of opiate substitution therapy in adults. Although unintentional methadone intoxication in children is rare, it is becoming more frequently recognized. We report 3 cases of unintentional methadone overdose in toddlers who initially displayed central nervous system depression associated with severe nonketotic hyperglycemia and discuss the possible pathophysiologic mechanisms of an underrecognized symptom of opiate intoxication in young children.

Noninvasive positive pressure ventilation: five years of experience in a pediatric intensive care unit.

OBJECTIVES: To evaluate the feasibility and outcome of noninvasive positive pressure ventilation (NPPV) in daily clinical practice. DESIGN: Observational retrospective cohort study. SETTING: Pediatric intensive care unit in a university hospital. PATIENTS: : Patients treated by NPPV, regardless of the indication, during five consecutive years (2000-2004). MEASUREMENTS AND RESULTS: A total of 114 patients were included, and 83 of the 114 patients (77%) were successfully treated by NPPV without intubation (NPPV success group). The success rate of NPPV was significantly lower (22%) in the patients with acute respiratory distress syndrome (p < .05) than in the other patients. The Pediatric Risk of Mortality II (p = .003) and Pediatric Logistic Organ Dysfunction scores (p = .002) at admission were significantly higher in patients who were unsuccessfully treated with NPPV (NPPV failure group). Baseline values of Pco2, pulse oximetry, and respiratory rate did not differ between the two groups. A significant decrease in Pco2 and respiratory rate within the first 2 hrs of NPPV was observed in the NPPV success group. Multivariate analysis showed that a diagnosis of acute respiratory distress syndrome (odds ratio, 76.8; 95% confidence interval, 4.4-1342; p = .003) and a high Pediatric Logistic Organ Dysfunction score (odds ratio, 1.09; 95% confidence interval, 1.01-1.17; p = .01) were independent predictive factors for NPPV failure. A total of 11 patients (9.6%), all belonging to the NPPV failure group, died during the study. CONCLUSIONS: This study demonstrates the feasibility and efficacy of NPPV in the daily practice of a pediatric intensive care unit. This ventilatory support could be proposed as a first-line treatment in children with acute respiratory distress, except in those with a diagnosis of acute respiratory distress syndrome.