Successful use of extracorporeal membrane oxygenation for pH1N1-induced refractory hypoxemia in a child with hypoplastic left heart syndrome.

OBJECTIVE: To report the first successful use of extracorporeal membrane oxygenation for acute respiratory distress syndrome secondary to 2009 pH1N1 influenza A infection in a child status post the Fontan operation for hypoplastic left heart syndrome. DESIGN: Individual case report. SETTING: Pediatric intensive care unit. PATIENT: We describe a 7-yr-old boy with a history of the Fontan operation for hypoplastic left heart syndrome admitted with acute respiratory distress syndrome secondary to 2009 pH1N1 influenza A infection. INTERVENTION: Cannulation for venoarterial extracorporeal membrane oxygenation. MEASUREMENTS AND MAIN RESULTS: In this patient with a history of complex congenital heart disease and repair, extracorporeal membrane oxygenation was a successful rescue therapy for refractory pH1N1-induced respiratory failure. CONCLUSION: Extracorporeal membrane oxygenation can be successfully applied for refractory respiratory failure, even in the setting of significant underlying comorbidity. With emerging data to support the role of extracorporeal membrane oxygenation in improving mortality for refractory hypoxemia secondary to pH1N1, it is prudent to strongly consider the use of extracorporeal support in patients with underlying diseases or comorbidities that may have previously precluded them from being candidates for this therapy.

Development of a collaborative program to provide extracorporeal membrane oxygenation for adults with refractory hypoxemia within the framework of a pandemic.

OBJECTIVE: We report the process used to rapidly develop a collaborative adult respiratory extracorporeal membrane oxygenation program as a response to caring for young adult patients with refractory hypoxemia in the setting of the pH1N1 pandemic. DESIGN: Interdisciplinary response of a complex medical system to a public health crisis. PATIENTS, INTERVENTIONS, MEASUREMENTS, AND MAIN RESULTS: After the successful use of extracorporeal membrane oxygenation in young adults with pH1N1-induced acute respiratory distress syndrome refractory to conventional therapies, an adult venovenous extracorporeal membrane oxygenation program was implemented over an 8-wk period. Implementation of this program involved a number of key steps that were crucial in the development process, including administrative and institutional support, multidisciplinary leadership and collaboration, extensive interdisciplinary educational initiatives, and substantial technical modifications. CONCLUSIONS: In the setting of the pH1N1 influenza pandemic, an adult respiratory extracorporeal membrane oxygenation program was successfully developed to complement an established neonatal-pediatric program. This program expansion integrated all of the necessary components involved in the development process from start to finish and confirms that a healthcare system can respond very quickly and successfully to an urgent healthcare need.

Extracorporeal membrane oxygenation for severe refractory respiratory failure secondary to 2009 H1N1 influenza A.

BACKGROUND: Respiratory failure and acute respiratory distress syndrome secondary to H1N1 influenza infection is a source of substantial morbidity and mortality, having caused over 265,000 hospitalizations in the United States in 2009. During the H1N1 pandemic, up to 31% of the H1N1 patients required intensive care unit admission, and many were refractory to maximal conventional therapies. These most critically ill patients may require extracorporeal membrane oxygenation (ECMO) for survival. METHODS: We retrospectively reviewed the medical records of the 7 patients with refractory hypoxemia due to H1N1 influenza who were treated with ECMO in our pediatric intensive care unit. RESULTS: Five of the 7 patients survived to hospital discharge. The cohort's mean age was 21 years, and 4 were female. At admission to the pediatric intensive care unit, 6 had at least one comorbid condition, 6 were mechanically ventilated, and one was in shock. All 7 patients were treated with oral oseltamivir, high-frequency oscillatory ventilation, and inhaled nitric oxide prior to ECMO. Five received intravenous steroids, and 2 were treated with compassionate-use intravenous zanamivir. The mean duration of pre-ECMO ventilation was 8.7 days (range 14 h to 25 d). Mean oxygenation index was 50 (range 26-73) at ECMO cannulation. Six received venovenous ECMO, and one received venoarterial ECMO. The mean duration of ECMO was 432 hours (range 192-890 h). CONCLUSIONS: This series suggests that ECMO is a viable treatment for refractory hypoxemia secondary to H1N1 influenza infection in both pediatric and adult patients.

Continuous High-Frequency Oscillation Therapy in Invasively Ventilated Pediatric Subjects in the Critical Care Setting.

BACKGROUND: Continuous high-frequency oscillation (CHFO) creates a pressure gradient in the small airways that accelerates expiratory flow. The intended use of CHFO therapy is to facilitate secretion removal and treat atelectasis. Our objective was to assess the feasibility, safety, and efficacy of CHFO in the mechanically ventilated pediatric population. METHODS: After institutional review board approval, we retrospectively reviewed medical records of mechanically ventilated children treated with CHFO (the MetaNeb system) at our institution from July 1, 2007 through August 31, 2012. Patients supported with extracorporeal membrane oxygenation were excluded. We evaluated changes in ventilator settings in subjects with ventilator data documented within 6 h pre- and post-treatment. We evaluated arterial blood gas (ABG) results for individual treatments, comparing ABG results within 8 h pre-therapy to ABG results within 3 h post-treatment. Oxygen index and PaO2 /FIO2 were calculated. Demographic data, blood pressure, heart rate, and development of new air leak while being treated with CHFO were recorded. Pre- and post-CHFO measurements were compared using Wilcoxon signed-rank testing. RESULTS: Our cohort included 59 invasively ventilated subjects. Median age was 2 y (range 1 month to 19 y), and median weight was 14 kg (2-81 kg). We evaluated data on 528 total treatments (range per subject 1-39 treatments). Peak inspiratory pressure significantly decreased with CHFO, whereas other parameters, including PaCO2 and breathing frequency, remained stable. There was no significant change in systolic blood pressure, diastolic blood pressure, or heart rate following treatment with CHFO. One subject (2%) developed a clinically insignificant pneumothorax during CHFO. CONCLUSIONS: CHFO is feasible and seems safe in our cohort of mechanically ventilated pediatric subjects. The rate of pneumothorax was consistent with that seen in similar pediatric ICU populations. These preliminary results suggest that CHFO may be beneficial by improving lung compliance in pediatric subjects with secretion-induced atelectasis. Prospective clinical studies are needed to further evaluate the clinical efficacy and safety of CHFO in children receiving invasive mechanical ventilation.

Circuit oxygenator contributes to extracorporeal membrane oxygenation-induced hemolysis.

Hemolysis can occur as a consequence of extracorporeal membrane oxygenation (ECMO) and is associated with increased mortality and morbidity. Shear stress generated by flow through the circuit and oxygenator is believed to cause ECMO-induced hemolysis. We hypothesize that either a smaller dimension oxygenator or an in-line hemofilter will increase ECMO-associated hemolysis. Circuits were configured with a Quadrox-D Adult oxygenator (surface area 1.8 m), Quadrox-iD Pediatric oxygenator (surface area 0.8 m), or Quadrox-D Adult oxygenator with an in-line hemofilter (N = 4) and ran for 6 hours. Samples were collected hourly from the ECMO circuit and a time-based hemolysis control. Plasma hemoglobin levels were assayed. Circuit-induced hemolysis at each time point was defined as the change in plasma hemoglobin standardized to the time-based hemolysis control. Plasma hemoglobin increased with the use of the smaller dimension pediatric oxygenator as compared with the adult oxygenator when controlling for ECMO run time (p = 0.02). Furthermore, there was a greater pressure gradient with the smaller dimension pediatric oxygenator (p < 0.05). Plasma hemoglobin did not change with the addition of the in-line hemofilter. The use of a smaller dimension pediatric oxygenator resulted in greater hemolysis and a higher pressure gradient. This may indicate that the increased shear forces augment ECMO-induced hemolysis.

Preparation of the critically ill neonate for transport.

Transport of a critically ill neonate is stressful for all involved. Adequate communication and stabilization will reduce stresses and improve outcomes. Periodic review of the stabilization and care provided to neonates prior to transport can help in further improving the process. Such reviews can be done in conjunction with the Regional Perinatal Center.