Effects of Noninvasive Positive Pressure Ventilation on Oxygenation Status and Prognosis in Patients With Acute Paraquat-Induced Lung Injury

Purpose The aim of this study was to evaluate the effects of noninvasive positive pressure ventilation (NIPPV) on oxygenation status and prognosis in patients with acute lung injury induced by paraquat (PQ) poisoning. Methods Patients with acute PQ-induced lung injury treated with NIPPV were admitted to an emergency intensive care unit. Changes in oxygenation status (respiratory rate and the partial pressure of alveolar O 2 and CO 2 [PaO 2 and PaCO 2 , respectively]) after initial NIPPV were observed. Differences in inspiratory pressure (PI) between nonsurvivors and survivors were compared. The relationship between PI and the prognosis of patients with acute PQ-induced lung injury was evaluated. Findings A total of 86 patients (47 women, 39 men; mean age, 33.5 [24.5] years [range, 22–61 years]) were included. There were significant differences in respiratory rate, PaO 2 , and PaCO 2 from before to after initial NIPPV (respiratory rate, 35 [14] vs 26 [16] min –1 [ P = 0.037]; PaO 2 , 61.8 [19.6] vs 73.5 [26.8] mm Hg [ P = 0.046]; and PaCO 2 , 27.7 [16.4] vs 34.6 [19.2] mm Hg [ P = 0.039]). The overall mortality rate was 75.6% (65/86) during a 28-day follow-up period. We observed a significant difference in initial PI (PI init ) between nonsurvivors and survivors (8.2 [4.3] vs 6.6 [3.8] cm H 2 O; P = 0.043). Furthermore, nonsurvivors had a greater maximal PI (PI max ) than did survivors (21.6 [9.8] vs 15.4 [8.5] cm H 2 O; P = 0.022). Correlation analysis revealed that both PI init and PI max were associated with a poor prognosis in patients with acute PQ-induced lung injury (PI init , r = –0.29 [ P = 0.038]; PI max , r = –0.31 [ P = 0.042]). Implications NIPPV may effectively improve oxygenation status in patients with acute PQ-induced lung injury, thereby relieving dyspnea and promoting the recovery of pulmonary function. PI init and PI max may be important determinants of prognosis in acute PQ-induced lung injury. These findings need further verification in a large-scale, multicenter, randomized controlled study that combines other factors with a relatively long-term follow-up.