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Volume 3 Supplement 1


Impact of non-invasive mechanical ventilation (niv) in critical patients with influenza (H1N1) PDM09


The use of non-invasive mechanical ventilation (NIV) in patients with influenza A (H1N1)pdm09 admitted to intensive care units (ICU) has been controversial.


Our objective was to assess the incidence of failure in NIV in this group of patients and their impact on ICU mortality rate.


Secondary analysis of prospective observational multicentric study in 148 spanish ICUs. Data was obtained of GTEI / SEMICYUC (2009-2014) registry. All patients with Influenza Virus A (H1N1) confirmed with rt-PCR were included. Ventilatory strategy, demographics and hemodynamic data, comorbidities and severity indexes were evaluated and they were correlated with mortality. Chi-square (categorical variables) and “t” test or Mann-Whitney test (continuous variables) analysis were performed. Significant variables in the univariate analysis were included in a multivariate model (conditional logistic regression). A “p” value less than 0.05 was considered significant.


2.223 patients were included in the analysis with a mortality 21.1% (n = 470 patients). 1726 patients were ventilated (77.6%), 962 (55.7%) of them were initially intubated, and in 764 (44.3%) NIV was initiated. NIV failed in 464 (60.7%) while 300 patients were responders (39.3%). Patients who died presented: older age (53.5 [15.34] vs. 48.5[15.1], p = 0.000), predominantly male (65% vs. 35%, p = 0.000), higher APACHEII (21[8] vs.14[6], p = 0.000) and SOFA (8[3] vs. 5[3], p = 0.000), more shock (79% vs. 44%, p < 0.000), more acute renal failure (49% vs. 18%, p = 0.000), more comorbidities (asthma, heart failure, renal failure and immunosuppression, p < 0.001), more days of mechanical ventilation (12.9[13.4]vs.9.4[13.2], p = 0.000) and longer hospital stay (23.2[19.3]vs. 16.6[15.6]p = 0.000). NIV failed group patients, had higher mortality (36%) than NIV successful group (4%, p = 0.000) and initially intubated group (31%, p = 0.07). Furthermore, the failure of NIV (OR=10.2, 95%IC 5.28-19.76, p = 0.000), the APACHEII (OR=1,05, 95%IC 1.02-1.09, p = 0.004), acute renal failure (OR=2.48, 95% IC 1.52-4.05, p = 0.000) and immunodeficiency (OR=5.66, 95%IC 3.02-10.60, p = 0.000) were independently variables associated with mortality in the multivariate analysis.


In our population of patients with influenza A (H1N1)pdm09, the failure of NVI is frequently and is associate independently with the ICU mortality.


  1. Recommendations of the Infectious Diseases Work Group (GTEI) of the Spanish Society of Intensive and Critical Care Medicine and Coronary Units (SEMICYUC) and the Infections in Critically Ill Patients Study Group (GEIPC) of the Spanish Society of Infectious Diseases and Clinical Microbiology (SEIMC) for the diagnosis and treatment of influenza A/H1N1 in seriously ill adults admitted to the Intensive Care Unit Med Intensiva. 2012, 36 (2): 103-37. Mar

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We are thankful to SEMICYUC/GETGAG working group

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Ferri, C., Marin-Corral, J., Magret, M. et al. Impact of non-invasive mechanical ventilation (niv) in critical patients with influenza (H1N1) PDM09. ICMx 3 (Suppl 1), A702 (2015).

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