Corticosteroid therapy in intensive care unit patients with PCR-confirmed influenza A(H1N1) infection in Finland

To evaluate the incidence, treatment, and outcome of influenza A(H1N1) in Finnish intensive care units (ICUs) with special reference to corticosteroid treatment.

During the H1N1 outbreak in Finland between 11 October and 31 December 2009, we prospectively evaluated all consecutive ICU patients with high suspicion of or confirmed pandemic influenza A(H1N1) infection. We assessed severity of acute disease and daily organ dysfunction. Ventilatory support and other concomitant treatments were evaluated and recorded daily throughout the ICU stay. The primary outcome was hospital mortality.

During the 3-month period altogether 132 ICU patients were tested polymerase chain reaction-positive for influenza A(H1N1). Of these patients, 78% needed non-invasive or invasive ventilatory support. The median (interquartile) length of ICU stay was 4 [2-12] days. Hospital mortality was 10 of 132 [8%, 95% confidence interval (CI) 3-12%]. Corticosteroids were administered to 72 (55%) patients, but rescue therapies except prone positioning were infrequently used. Simplified Acute Physiology Score II and Sequential Organ Failure Assessment scores in patients with and without corticosteroid treatment were 31 [24-36] and 6 [2-8] vs. 22 [5-30] and 3 [2-6], respectively. The crude hospital mortality was not different in patients with corticosteroid treatment compared to those without: 8 of 72 (11%, 95% CI 4-19%) vs. 2 of 60 (3%, 95% CI 0-8%) (P = 0.11).

The majority of H1N1 patients in ICUs received ventilatory support. Corticosteroids were administered to more than half of the patients. Despite being more severely ill, patients given corticosteroids had comparable hospital outcome with patients not given corticosteroids.