Analysis of Noninvasive Ventilation in Subjects With Sepsis and Acute Respiratory Failure

BACKGROUND: Acute respiratory failure is among the sequelae of complications that can develop in response to severe sepsis. Research into sepsis-related respiratory failure has focused on ARDS and invasive mechanical ventilation. We studied the factors associated with success and failure of noninvasive ventilation (NIV) in the treatment of sepsis-related acute respiratory failure.

METHODS: This retrospective study included 136 subjects with a diagnosis of acute respiratory failure and intrapulmonary or extrapulmonary sepsis who were placed on NIV. Subjects were divided into 2 groups based on the need for intubation from NIV: NIV failure (n = 70) and NIV success (n = 66). Demographic, clinical, and outcome data were collected and compared between groups, with the development of multivariate models to predict NIV failure and mortality.

RESULTS: The overall NIV failure rate in subjects with a diagnosis of sepsis was 51%. There were no between-group differences in demographic or baseline characteristics. However, there were significant differences in clinical variables, with higher SOFA scores (NIV failure: 6.4 [± 3.0] vs NIV success: 4.9 [± 2.1]; P = .002), 2nd lactate levels (NIV failure: 2.6 [1.7 – 4.3] vs NIV success: 1.9 [1.4 – 2.6] mmol/L; P = .007), and initial NIV settings (NIV failure: 0.50 [0.40 – 0.70] vs NIV failure: 0.40 [0.35 – 0.50]; P = .003) in subjects who failed NIV. There were also more subjects in the NIV failure group who had a lactate ≥ 4 mmol/L prior to NIV start compared to those who succeeded on NIV (33% vs 15%, P = .02). At NIV start, subjects in the NIV failure group had lower mean arterial pressure (85 mm Hg [IQR 74–96] vs 91.7 mm Hg [IQR 78–108], P = .042) and Glasgow coma scale scores (14 [IQR 13–15] vs 15 [IQR 14–15], P < .002), while fewer subjects in the NIV failure group received a fluid bolus in the 24 h prior to NIV start (33% vs 53%, P = .02) or had signs of volume overload (36% vs 64%, P < .001). Multivariate analysis indicated that age (odds ratio 1.05 [95% CI 1.01–1.09], P = .02), SOFA score (odds ratio 1.49 [95% CI 1.15–1.94], P = .002), first systolic blood pressure (odds ratio 0.97 [95% CI 0.95–0.99], P = .02), signs of volume overload (odds ratio 0.23 [95% CI 0.07–0.68], P = .008], fluids prior to NIV (odds ratio 0.08 [95% CI 0.02–0.31], P < .001), and initial on NIV (odds ratio 1.04 [95% CI 1.01–1.08, P = .002) independently predicted NIV failure with an area under the curve of 0.88. Only NIV failure independently predicted death in multivariate analysis (area under the curve = 0.70).

CONCLUSIONS: NIV failure in sepsis-related acute respiratory failure was independently predicted by patient acuity, first systolic blood pressure after sepsis alert, initial settings on NIV, fluid resuscitation, and signs of volume overload. However, only NIV failure independently predicted death in this cohort of subjects.