Claire Westrope

Venovenous Extracorporeal Membrane Oxygenation for Respiratory Failure in Inotrope Dependent Neonates

It is often stated that venovenous extracorporeal membrane oxygenation (VV ECMO) should not be used in inotrope dependent patients. It is our practice to use VV ECMO in most patients with respiratory failure even though many of these patients are receiving significant doses of inotropes. Our objective was to review the mode of ECMO in relation to precannulation doses of inotropes administered to neonates treated with ECMO for respiratory failure.Forty-three consecutive case notes were reviewed. Data were collected for basic demographic and ECMO parameters. Inotropic doses were converted to a single score for ease of comparison, with one point equivalent to 1 &mgr;g/kg/min dopamine.Forty-three neonates were studied; 37(86%) were treated with VV ECMO and 6 (14%) were treated with VA ECMO. Significant pre-ECMO inotropic support (score > 10) was present in 30 (70%) of the 43 cases. Of these patients, 26 were treated via VV ECMO with a survival rate of 84%, while 4 were treated with VA ECMO with a survival of 75%. Inotrope scores fell to nonsignificant levels (< 10) within 24 hours, regardless of ECMO mode. Mean arterial blood pressure remained above precannulation levels in both groups.VV ECMO allows safe treatment of neonatal respiratory failure in the presence of significant inotropic support. We recommend VV ECMO for neonatal respiratory failure in all cases except where double lumen cannulation is impossible or when septic shock is refractory to inotropic support (i.e., mean blood pressure < 35 mm Hg despite inotrope score of > 100).

Performance of polymethyl pentene oxygenators for neonatal extracorporeal membrane oxygenation: a comparison with silicone membrane oxygenators

Objective: To review the performance of polymethyl pentene versus silicone oxygenators in terms of efficiency in priming and oxygenation, oxygenator resistance, requirements for coagulation proteins and consumption of blood products, for neonatal extracorporeal membrane oxygenation (ECMO) patients. Study design: Forty consecutive neonates were selected retrospectively pre- and post-introduction of the new polymethyl pentene (PMP) oxygenators. They formed two equal groups. After calculation of the sample size, data were collected from ELSO registry forms and patient records. Results were analysed using parametric and non-parametric tests. Results: Neonatal PMP (N-PMP) oxygenators were smaller, faster and easier to prime. They were less efficient than silicone oxygenators, especially in carbon dioxide elimination, and, therefore, required higher sweeps. The preservation of coagulation proteins was significantly better, but there was no reduction in the consumption of blood products, despite having less than half the surface area and significantly lower blood path resistance. Conclusion: Small PMP oxygenators (Medos Hilite 800 LT) provide adequate gas exchange and offer technical advantages in terms of more efficient priming, reduced haemodynamic resistance and better control and preservation of coagulation proteins than silicone oxygenators.

Experience with mobile inhaled nitric oxide during transport of neonates and children with respiratory insufficiency to an extracorporeal membrane oxygenation center.

Objective: To share our experience with the use of inhaled nitric oxide (iNO) during the transport of ventilated neonates and children to an extracorporeal membrane oxygenation (ECMO) center and to discuss the efficacy and safety of iNO use in this situation. Data Sources: Case note review of 55 consecutive patients transported while receiving iNO to Glenfield Hospital, Leicester, UK, for consideration of ECMO. Study Selection: Retrospective case note review. Data Extraction: The clinical condition of each patient recorded at arrival of the transport team at the referring hospital, during transport, and at arrival at Glenfield Hospital. Preclinical and postclinical conditions were compared using the paired Student’s t-test. Data Synthesis: Overall data showed a significant improvement in transcutaneous oximetry measurements (Spo2: 84.8% preclinical, 90.6% postclinical; p = .006) and Pao2 (59 torr [7.87 kPa] preclinical, 84 torr [11.23 kPa] postclinical; p = .001) during transport in our patient group. Based on limited safety data, no untoward events or toxic metabolites were observed with iNO therapy during transport. Conclusions: iNO does appear to improve oxygenation during transfer of patients for ECMO in our series. Based on limited safety data, iNO appears safe to use in transport.

Pump controlled retrograde trial off from VA-ECMO.

We describe our novel technique of Pump Controlled Retrograde Trial Off that relies on the retrograde flow to maintain circuit integrity and allow a longer trial off from venoarterial extracorporeal membrane oxygenation support without circuit clot formation or significant patient hemodynamic compromise. This technique avoids the insertion of an arteriovenous bridge and the need to clamp the circuit. We present data on five neonatal patients who were trialled off using this method.

The use of extracorporeal membrane oxygenation in neonates with severe congenital diaphragmatic hernia: a 26-year experience from a tertiary centre†.

OBJECTIVES Neonates with severe congenital diaphragmatic hernia requiring extracorporeal membrane oxygenation (ECMO) have a high rate of mortality. There is controversy regarding optimal time of surgical intervention. We present our data over a 26‐year period. METHODS We analysed data from our Extracorporeal Life Support Organization registry forms between 1989 and 2015, in order to determine the factors affecting survival outcome for repair of congenital diaphragmatic hernia with ECMO as a bridge to surgery and/or recovery. RESULTS Ninety‐eight neonates with congenital diaphragmatic hernia requiring ECMO were identified. In‐hospital mortality was 32%. The overall mortality (47.9%) in our study was seen up to 7 months, after this point there was no mortality. There was no difference in survival in patients repaired using pre‐, intra‐ or postoperative ECMO (P = 0.65). Requiring haemofiltration at any point was significantly associated with reduced survival [hazard ratio 2.7 (95% confidence interval 1.5‐4.9); P = 0.01] as was the presence of neurological complications [hazard ratio 3.7 (95% confidence interval 1.6‐8.5); P = 0.003]. Age, Apgar score, mode of delivery, side, associated cardiac comorbidities, pH, partial pressure of carbon dioxide, partial pressure of oxygen, oxygen saturations, bicarbonate, high‐frequency oscillatory ventilation, mode of ECMO, inhaled nitric oxide, pulmonary complications and bleeding were not associated with any survival difference. CONCLUSIONS We believe that all neonates with severe diaphragmatic hernia should be given the option of ECMO if clinically indicated. Provided these patients survive the initial postoperative period, they go on to have a sustained survival benefit. Long‐term cost analysis and morbidity need to be taken into account to determine the true effect of ECMO on congenital diaphragmatic hernia.

Experience of Circuit Survival in Extracorporeal Continuous Renal Replacement Therapy Using Small-Calibre Venous Cannulae.

Objectives: To describe an experience of circuit survival in extracorporeal continuous renal replacement therapy using small-calibre (< 7 French gauge [F]) venous cannulae. Design: An observational study. Setting: A multidisciplinary, university-affiliated PICU. Subjects: Case note review of all continuous renal replacement therapy episodes (1998–2010), which used vascular access cannulae of an external diameter less than 7F, was performed. Measurements and Main Results: Forty-nine patients underwent continuous renal replacement therapy treatment during which circuit blood flow was delivered using either 5F or 6.5F double-lumen cannulae. One hundred thirty-nine circuits were employed (median per patient, 2; interquartile range, 1–3) in providing 4,903 hours of therapy (median duration of therapy, 43 hr; interquartile range, 22–86 hr); allowing for censoring, the median circuit survival time was 40 hours (95% CI, 28–66). Eighty-one circuits (58%) failed because of clotting/technical problems, equating to a circuit failure rate of 16.5 (95% CI, 13.3–20.5) per 1,000 hours of continuous renal replacement therapy. The probability of a circuit surviving 40 hours or greater was 50% with 43% (95% CI, 34–53%) expected to survive 60 hours or more. No significant relationship between circuit survival and the calibre of the cannula deployed was identified; however, placement of venous access in an internal jugular vein was associated with improved circuit survival. Conclusions: Contrary to previous reports, vascular access cannulae of a caliber less than 7F can support sufficiently prolonged continuous renal replacement therapy to make them a useful means of delivering renal support in neonates and small infants.