Extracorporeal lung support in H1N1 provoked acute respiratory failure: the experience of the German ARDS Network

Abstract

Background: During the H1N1 pandemic of 2009 and 2010, the large number of patients with severe respiratory failure due to H1N1 infection strained the capacities of treatment facilities for extracorporeal membrane oxygenation (ECMO) around the world. No data on this topic have yet been published for Germany.

Methods: During the pandemic, the German ARDS Network (a task force of the DIVI's respiratory failure section) kept track of the availability of ECMO treatment facilities with a day-to-day, Internet-based capacity assessment. In cooperation with the Robert Koch Institute, epidemiological and clinical data were obtained on all patients treated for influenza in intensive care units.

Results: 116 patients were identified who had H1N1 disease and were treated in the intensive care units of 9 university hospitals and 3 other maximum medical care hospitals. 61 of them received ECMO. The overall mortality was 38% (44 of 116 patients); among patients receiving ECMO, the mortality was 54% (33 of 61 patients). The mortality was higher among patients who had an accompanying malignancy or immune deficiency (72.2%).

Conclusion: Even persons without any other accompanying disease developed life-threatening respiratory failure as a result of H1N1 infection, and many of these patients needed ECMO. This study reveals for the first time that the mortality of H1N1 infection in Germany is comparable to that in other countries. H1N1 patients with acute respiratory failure had a worse outcome if they also had serious accompanying diseases.

Figure 1

Capacity data collection for extracorporeal lung support systems (“traffic light“) within the “Acute Respiratory Distress Syndrome“ (ARDS) network for the period from 2009 (calendar week 48) to 2010 (calendar week 14). Blue represents limited admission capacity and red no admission capacity. The heights of the bars represent the percentage of the respective reported data (blue or red) of the reported data total (yellow, red or green) within the respective calendar week. Altogether 40 hospitals contributed to the capacity data collection

Figure 2

IV contrast-enhanced chest CT scan (lung window) in a 47-year-old male patient with influenza provoked acute respiratory distress syndrome (ARDS). Ground glass–type increases in density (a, black arrow) and areas of consolidation (b, white arrow) are recognizable. Reprinted from: Grieser C, Goldmann A, Steffen I et al.: Computed tomography findings from patients with ARDS due to Influenza A (H1N1) virus-associated pneumonia. Eur J Radiol 2012; 81: 389–94. Used by permission of the publisher (Elsevier)

Figure 3

Odds ratios for the outcome variable ’mortality’, dependent on body mass index, age, performance of an ECMO therapy, SOFA score or PaO2/FIO2 ratio on ICU admission, as well as presence of concomitant malignant or immunological diseases (“comorbidities”). Logarithmic scale, logistic regression, level of significance: p<0.05. ECMO, extracorporeal membrane oxygenation (extracorporeal lung support therapy); SOFA, Sequential Organ Failure Assessment