Clinical characteristics and outcomes of patients with 2009 influenza A(H1N1) virus infection with respiratory failure requiring mechanical ventilation

• Published in: Journal of critical care 2011-04, Vol.26 (2), p.186-192
• Main Authors: Nin, Nicolás, MD, PhD, Soto, Luis, MD, Hurtado, Javier, MD, Lorente, José A., MD, PhD, Buroni, María, MD, Arancibia, Francisco, MD, Ugarte, Sebastian, MD, Bagnulo, Homero, MD, Cardinal, Pablo, MD, Bugedo, Guillermo, MD, Echevarría, Estrella, MD, Deicas, Alberto, MD, Ortega, Carlos, MD, Frutos-Vivar, Fernando, MD, Esteban, Andrés, MD, PhD
• Format: Article
• Language: English
• Subjects: Adult; ARDS; Bacterial infections; Blood; Confidence intervals; Critical Care; Data collection; Female; H1N1; Hospital Mortality; Humans; Hypoxia - etiology; Hypoxia - mortality; Influenza; Influenza A Virus, H1N1 Subtype; Influenza, Human - complications; Influenza, Human - mortality; Intensive care; Male; Mechanical ventilation; Middle Aged; Mortality; Multiple Organ Failure - etiology; Multiple Organ Failure - mortality; Multivariate analysis; Pandemics; Pneumonia; Pneumonia, Bacterial - complications; Pneumonia, Bacterial - mortality; Polymerase chain reaction; Positive-Pressure Respiration; Reporting requirements; Respiratory Distress Syndrome, Adult - etiology; Respiratory Distress Syndrome, Adult - mortality; Severity of Illness Index; Shock - etiology; Shock - mortality; Statistical analysis; Streptococcus infections; Ventilation
• ISSN: 0883-9441; 1557-8615
• DOI: 10.1016/j.jcrc.2010.05.031

Abstract Purpose The purpose of the study was to describe the clinical characteristics and outcomes of critically ill patients with 2009 influenza A(H1N1). Methods An observational study of patients with confirmed or probable 2009 influenza A(H1N1) and respiratory failure requiring mechanical ventilation was performed. Results We studied 96 patients (mean age, 45 [14] years [mean, SD]; 44% female). Shock and acute respiratory distress syndrome were diagnosed during the first 72 hours of admission in 43% and 72% of patients, respectively. Noninvasive positive pressure ventilation was used in 45% of the patients, but failed in 77% of them. Bacterial pneumonia was diagnosed in 33% of cases, 8% during the first week (due to community-acquired microorganisms) and 25% after the first week (due to gram-negative bacilli and resistant gram-positive cocci). Intensive care unit mortality was 50%. Nonsurvivors differed from survivors in the prevalence of cardiovascular, respiratory, and hematologic failure on admission and late pneumonia. Reported causes of death were refractory hypoxia, multiorgan failure, and shock (50%, 38%, and 12% of all causes of death, respectively). Conclusions Patients with 2009 influenza A(H1N1) and respiratory failure requiring mechanical ventilation often present with clinical criteria of acute respiratory distress syndrome and shock. Bacterial pneumonia is a frequent complication. Mortality is high and is primarily due to refractory hypoxia.