Influenza A (H1N1pdm09)-Related Critical Illness and Mortality in Mexico and Canada, 2014.
Crit Care Med. 2016 Jun 29;
Authors: Dominguez-Cherit G, De la Torre A, Rishu A, Pinto R, Ñamendys-Silva SA, Camacho-Ortiz A, Silva-Medina MA, Hernández-Cárdenas C, Martínez-Franco M, Quesada-Sánchez A, López-Gallegos GC, Mosqueda-Gómez JL, Rivera-Martinez NE, Campos-Calderón F, Rivero-Sigarroa E, Hernández-Gilsoul T, Espinosa-Pérez L, Macías AE, Lue-Martínez DM, Buelna-Cano C, Ramírez-García Luna AS, Cruz-Ruiz NG, Poblano-Morales M, Molinar-Ramos F, Hernandez-Torre M, León-Gutiérrez MA, Rosaldo-Abundis O, Baltazar-Torres JÁ, Stelfox HT, Light B, Jouvet P, Reynolds S, Hall R, Shindo N, Daneman N, Fowler RA
OBJECTIVES: The 2009-2010 influenza A (H1N1pdm09) pandemic caused substantial morbidity and mortality among young patients; however, mortality estimates have been confounded by regional differences in eligibility criteria and inclusion of selected populations. In 2013-2014, H1N1pdm09 became North America's dominant seasonal influenza strain. Our objective was to compare the baseline characteristics, resources, and treatments with outcomes among critically ill patients with influenza A (H1N1pdm09) in Mexican and Canadian hospitals in 2014 using consistent eligibility criteria.
DESIGN: Observational study and a survey of available healthcare setting resources.
SETTING: Twenty-one hospitals, 13 in Mexico and eight in Canada.
PATIENTS: Critically ill patients with confirmed H1N1pdm09 during 2013-2014 influenza season.
MEASUREMENTS AND MAIN RESULTS: The main outcome measures were 90-day mortality and independent predictors of mortality. Among 165 adult patients with H1N1pdm09-related critical illness between September 2013 and March 2014, mean age was 48.3 years, 64% were males, and nearly all influenza was community acquired. Patients were severely hypoxic (median PaO2-to-FIO2 ratio, 83 mm Hg), 97% received mechanical ventilation, with mean positive end-expiratory pressure of 14 cm H2O at the onset of critical illness and 26.7% received rescue oxygenation therapy with prone ventilation, extracorporeal life support, high-frequency oscillatory ventilation, or inhaled nitric oxide. At 90 days, mortality was 34.6% (13.9% in Canada vs 50.5% in Mexico, p < 0.0001). Independent predictors of mortality included lower presenting PaO2-to-FIO2 ratio (odds ratio, 0.89 per 10-point increase [95% CI, 0.80-0.99]), age (odds ratio, 1.49 per 10 yr increment [95% CI, 1.10-2.02]), and requiring critical care in Mexico (odds ratio, 7.76 [95% CI, 2.02-27.35]). ICUs in Canada generally had more beds, ventilators, healthcare personnel, and rescue oxygenation therapies.
CONCLUSIONS: Influenza A (H1N1pdm09)-related critical illness still predominantly affects relatively young to middle-aged patients and is associated with severe hypoxemic respiratory failure. The local critical care system and available resources may be influential determinants of patient outcome.
PMID: 27359085 [PubMed - as supplied by publisher]