Risk Factors for Noninvasive Ventilation Failure in Critically Ill Subjects With Confirmed Influenza Infection.

BACKGROUND: Despite wide use of noninvasive ventilation (NIV) in several clinical settings, the beneficial effects of NIV in patients with hypoxemic acute respiratory failure (ARF) due to influenza infection remain controversial. The aim of this study was to identify the profile of patients with risk factors for NIV failure using chi-square automatic interaction detection (CHAID) analysis and to determine whether NIV failure is associated with ICU mortality. METHODS: This work was a secondary analysis from prospective and observational multi-center analysis in critically ill subjects admitted to the ICU with ARF due to influenza infection requiring mechanical ventilation. Three groups of subjects were compared: (1) subjects who received NIV immediately after ICU admission for ARF and then failed (NIV failure group); (2) subjects who received NIV immediately after ICU admission for ARF and then succeeded (NIV success group); and (3) subjects who received invasive mechanical ventilation immediately after ICU admission for ARF (invasive mechanical ventilation group). Profiles of subjects with risk factors for NIV failure were obtained using CHAID analysis. RESULTS: Of 1,898 subjects, 806 underwent NIV, and 56.8% of them failed. Acute Physiology and Chronic Health Evaluation II (APACHE II) score, Sequential Organ Failure Assessment (SOFA) score, infiltrates in chest radiograph, and ICU mortality (38.4% vs 6.3%) were higher (P < .001) in the NIV failure than in the NIV success group. SOFA score was the variable most associated with NIV failure, and 2 cutoffs were determined. Subjects with SOFA ≥ 5 had a higher risk of NIV failure (odds ratio = 3.3, 95% CI 2.4-4.5). ICU mortality was higher in subjects with NIV failure (38.4%) compared with invasive mechanical ventilation subjects (31.3%, P = .018), and NIV failure was associated with increased ICU mortality (odds ratio = 11.4, 95% CI 6.5-20.1). CONCLUSIONS: An automatic and non-subjective algorithm based on CHAID decision-tree analysis can help to define the profile of patients with different risks of NIV failure, which might be a promising tool to assist in clinical decision making to avoid the possible complications associated with NIV failure.

Fluid balance in sepsis and septic shock as a determining factor of mortality.

OBJECTIVE: The objective was to assess whether fluid balance had a determinant impact on mortality rate in a cohort of critically ill patients with severe sepsis or septic shock. DESIGN: A prospective and observational study was carried out on an inception cohort. SETTING: The setting was an intensive care unit of a university hospital. PATIENTS: Patients admitted consecutively in the intensive care unit who were diagnosed with severe sepsis or septic shock were included. INTERVENTIONS: Demographic, laboratory, and clinical data were registered, as well as time of septic shock onset, illness severity (Simplified Acute Physiology Score II, Sepsis-related Organ Failure Assessment), and comorbidities. Daily and accumulated fluid balance was registered at 24, 48, 72, and 96 hours. Survival curves representing 28-day mortality were built according to the Kaplan-Meier method. RESULTS: A total of 42 patients were included in the analysis: men, 64.3%; mean age, 61.8±15.9 years. Septic shock was predominant in 69% of the cases. Positive blood cultures were obtained in 17 patients (40.5%). No age, sex, Sepsis-related Organ Failure Assessment, creatinine, lactate, venous saturation of O2, and troponin differences were observed upon admission between survivors and nonsurvivors. However, higher Simplified Acute Physiology Score II was observed in nonsurvivors, P=.016. Nonsurvivors also showed higher accumulated positive fluid balance at 48, 72, and 96 hours with statistically significant differences. Besides, significant differences (P=.02) were observed in the survival curve with the risk of mortality at 72 hours between patients with greater than 2.5 L and less than 2.5 L of accumulated fluid balance. CONCLUSIONS: Fluid administration at the onset of severe sepsis or septic shock is the first line of hemodynamic treatment. However, the accumulated positive fluid balance in the first 48, 72, and 96 hours is associated with higher mortality in these critically ill patients.