Failure factors of noninvasive positive pressure ventilation for perioperative critical ill patients in surgery intensive care unit

Abstract

Objective To evaluate the independent risk factor of noninvasive positive pressure ventilation (NPPV) treatment failure for perioperative critical ill patients in surgical intensive care unit (SICU), and guide the clinical application of NPPV in perioperative critical patients. Methods Patients undergoing NPPV due to acute respiratory insufficiency admitted to SICU of Peking University First Hospital from January 2004 to January 2016 were retrospectively analyzed by electronic medical record retrieval system. According to whether invasive ventilation was needed finally or not, perioperative patients treated with NPPV were divided into the success group and failure group. The patients' perioperative data were recorded including general state, the type of operation, acute physiology and chronic health evaluation Ⅱ (APACHEⅡ) score, the cause and the type of acute respiratory insufficiency (pulmonary, cardiogenic, excessive ventilation caused by severe systemic infection, etc.; type Ⅰ respiratory failure, type Ⅱ respiratory failure, simple hypercapnia, etc.), the related parameters of ventilator during NPPV, vital signs and blood gas analysis before and 1 hour after NPPV, NPPV related complications and prognostic indicators. Results 189 patients were enrolled, 109 patients in success group (57.7%), and 80 in failure group (42.3%). Compared with success group, patients in failure group were older (years: 69.14±14.24 vs. 62.33±16.03), had higher APACHE Ⅱ score (16.74±8.00 vs. 11.76±5.53) and incidence of pulmonary infection after operation (45.0% vs. 24.8%), and higher pressure support (PS) [cmH2O (1 cmH2O = 0.098 kPa): 12.38±2.08 vs. 11.29±2.18] and fraction of inspired oxygen (FiO2: 0.666±0.201 vs. 0.506±0.166) during NPPV, lower differences in pH value (0.01±0.07 vs. 0.03±0.06) and oxygenation index [PaO2/FiO2 (mmHg, 1 mmHg = 0.133 kPa): -10.53±57.01 vs. -59.47±71.14] before and after NPPV with statistically significant differences (all P 0.05], but the length of intensive care unit (ICU) stay was significantly prolonged [days: 9.5 (6.0, 16.0) vs. 5.0 (3.0, 8.0), P < 0.01], and the in-hospital mortality was significantly increased (67.5% vs. 2.8%, P < 0.01). Conclusions NPPV may be an effective and security method for treatment of acute respiratory insufficiency in perioperative critical patients. The independent risk factors associated with failure of NPPV were higher APACHE Ⅱ score, higher FiO2 during NPPV, lack of improvement PaO2/FiO2 at 1 hour after NPPV, and pulmonary infection after operation. Key words: Noninvasive positive pressure ventilation; Postoperation; Perioperative period; Respiratory insufficiency