2009 H1N1 Influenza and Experience in Three Critical Care Units

Teke, Turgut; Coskun, Ramazan; Sungur, Murat; Guven, Muhammed; Bekci, Taha T; Maden, Emin; Alp, Emine; Doganay, Mehmet; Erayman, Ibrahim; Uzun, Kursat

In our study, 92% of patients required ventilator support for profound hypoxemic respiratory failure, requiring high levels of inspired oxygen and PEEP. However, survival rate was higher in NIMV than invasive ventilation. We used full-face mask in all patients for NIMV. Noninvasive ventilation has been used an alternative therapy for patients with acute respiratory failure with hopes of obviating intubation and mechanical ventilation. The results of NIMV in hypoxemic respiratory failure have been conflicting, and the etiology of hypoxemia appears to be an important determinant of its success. Ferrer et al. (22) compared NIMV to conventional venture oxygen delivery in patients with severe hypoxemic respiratory failure and found that NIMV decreased the need for intubation. This benefit was observed in the subgroup of patients with pneumonia, but not in those with ARDS, in which the intubation rates were high in both groups. A meta-analysis suggests that NIMV does not decrease the need for intubation, so there is not enough evidence to support its use in ARDS (23) . Of all patients, 56 (91 %) were mechanically ventilated on the first day of ICU admission; 14 (23 %) invasively and 42 (68.8 %) noninvasively. Fifteen patients (24.5%) who received noninvasive ventilation ultimately required invasive ventilation. Dominguez-Cherit et al. (24) reported that invasively ventilation was used in 82.7% of patients. In Kumar's study (18) , invasive ventilation was used in 81% of patients with swine flu associated respiratory failure. In our study, we used noninvasive ventilation in 68.8% of critically patients with 2009 Influenza A (H1N1) on admission ICU. In critically ill patients with 2009 influenza A (H1N1) infection, high levels of PEEP were often used to achieve adequate oxygenation. In our study, patients with ARDS were often had PEEP refractory hypoxemia. It was also noted that once patients improved and the weaning process was started, oxygenation was sensitive to small decrements in PEEP. We used high PEEP levels up to 20-25 cmH2O in some patients.