Jeremy J. Cordingley

Referral to an Extracorporeal Membrane Oxygenation Center and Mortality Among Patients With Severe 2009 Influenza A(H1N1)

CONTEXT Extracorporeal membrane oxygenation (ECMO) can support gas exchange in patients with severe acute respiratory distress syndrome (ARDS), but its role has remained controversial. ECMO was used to treat patients with ARDS during the 2009 influenza A(H1N1) pandemic. OBJECTIVE To compare the hospital mortality of patients with H1N1-related ARDS referred, accepted, and transferred for ECMO with matched patients who were not referred for ECMO. DESIGN, SETTING, AND PATIENTS A cohort study in which ECMO-referred patients were defined as all patients with H1N1-related ARDS who were referred, accepted, and transferred to 1 of the 4 adult ECMO centers in the United Kingdom during the H1N1 pandemic in winter 2009-2010. The ECMO-referred patients and the non-ECMO-referred patients were matched using data from a concurrent, longitudinal cohort study (Swine Flu Triage study) of critically ill patients with suspected or confirmed H1N1. Detailed demographic, physiological, and comorbidity data were used in 3 different matching techniques (individual matching, propensity score matching, and GenMatch matching). MAIN OUTCOME MEASURE Survival to hospital discharge analyzed according to the intention-to-treat principle. RESULTS Of 80 ECMO-referred patients, 69 received ECMO (86.3%) and 22 died (27.5%) prior to discharge from the hospital. From a pool of 1756 patients, there were 59 matched pairs of ECMO-referred patients and non-ECMO-referred patients identified using individual matching, 75 matched pairs identified using propensity score matching, and 75 matched pairs identified using GenMatch matching. The hospital mortality rate was 23.7% for ECMO-referred patients vs 52.5% for non-ECMO-referred patients (relative risk [RR], 0.45 [95% CI, 0.26-0.79]; P = .006) when individual matching was used; 24.0% vs 46.7%, respectively (RR, 0.51 [95% CI, 0.31-0.81]; P = .008) when propensity score matching was used; and 24.0% vs 50.7%, respectively (RR, 0.47 [95% CI, 0.31-0.72]; P = .001) when GenMatch matching was used. The results were robust to sensitivity analyses, including amending the inclusion criteria and restricting the location where the non-ECMO-referred patients were treated. CONCLUSION For patients with H1N1-related ARDS, referral and transfer to an ECMO center was associated with lower hospital mortality compared with matched non-ECMO-referred patients.

A modified technique for insertion of dual lumen bicaval cannulae for venovenous extracorporeal membrane oxygenation

PurposeVenovenous extracorporeal membrane oxygenation is used increasingly in adults with severe acute reversible respiratory failure. Cannulation is associated with a risk of vascular damage or cardiac perforation.Methods and resultsThis report describes a modified technique of insertion for dual lumen bicaval cannulae. We have adopted the technique on 25 occasions and had no incidence of vascular damage or cardiac perforation.ConclusionWe suggest that the technique may mitigate the risk of guidewire looping during insertion of the dilators/cannula and thereby reduce the risk of perforation of the right ventricle.

ECMO in adults for severe respiratory failure finally comes of age: just in time?

The idea of employing cardiopulmonary bypass technology as a means of oxygenating (extracorporeal membrane oxygenation (ECMO)) or removing carbon dioxide (ECCO2R) in patients with acute respiratory failure (ARF) was first assessed in randomised controlled trials in the 1970s and 1980s.1 2 Poor rates of survival and major complications, particularly massive haemorrhage, led to most intensivists believing that ECMO was inappropriate in adults. A small number of centres worldwide—including that in Leicester, UK—continued to refine the use of ECMO in small numbers of adult patients whom it proved impossible to oxygenate by conventional means. Following the publication of their case series with improved results,3 Peek and colleagues embarked upon a randomised controlled trial of conventional ventilation or ECMO in patients with severe ARF (CESAR), the results of which have just been reported.4 Patients (n=766) were screened for inclusion over a 5-year period and those with potentially reversible severe ARF (defined as a Murray score >3 or …

Extracorporeal carbon dioxide removal to “protect” the lung

The case histories are presented of three adults who had severe hypercapnic acidosis despite mechanical ventilation with what were considered to be injurious tidal volumes and airway pressures. The use of a percutaneously inserted arteriovenous extracorporeal carbon dioxide removal (AV-ECCO2R) device facilitated a dramatic reduction in the amount of ventilatory support required, achieving a “lung-protective” level. Two patients survived to hospital discharge. One patient died after it became apparent that her late-stage interstitial lung disease was unresponsive to immunosuppression. AV-ECCO2R may be a useful strategy in facilitating lung-protective ventilation.