Ventilatory strategy based on biphasic positive airway pressure (BIPAP/APRV), preventive ventilation, and high PEEP for patients with acute respiratory distress syndrome (ARDS) and acute lung injury (ALI) associated to H1N1 virus infection

Abstract

pressure release ventilation as a rescue therapy was used in 49%, high-frequency ventilation in 26%, prone position in 14%, nitric oxide in 7%, and muscle relaxant in 43% of patients. Mortality increased steadily with increasing severity of illness, with an overall mortality rate of 35% for a mean APACHE IV score of 105.6. Mortality was 19% for the APACHE IV group of 40 to 90, 33% for the group of 91 to 140, and 73% for the group of 141 to 190. Mortality in pregnant women was 33%. Patients who received steroid therapy as part of adult respiratory distress syndrome management had a mortality rate of 47% compared with 23% for those who did not receive steroid therapy, with P value b .01 and odd ratio of 2.87 (95% confidence interval, 1.14-7.25). Late administration of oseltamivir (N48 hours of initial presentation) was associated with an overall mortality of 82% compared with 28% in those who received early oseltamivir, with a P value b .005 and odd ratio of 11.6 (95% CI, 2.3-58). Conclusions: Patients who were admitted to intensive care unit with severe 2009 H1N1 infection were young and had a relatively high severity of illness score. Most common risk factors were bronchial asthma, obesity, and pregnancy. Overall hospital mortality was 35%. Late administration of oseltamivir was associated with at least 12-fold increase in mortality. Steroid use was associated with about 3-fold increase in mortality.