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Table 2 Predictors of endotracheal intubation in patients receiving NIV for non-hypercapnic AHRF

From: Non-invasive ventilation for acute hypoxemic respiratory failure: intubation rate and risk factors

  NIV Success N = 52 NIV Failure N = 61 Univariate HR [95% CI]; P-value Cox regression aHR [95% CI]; P-value
Age, years 58.0 (± 17.1) 62.6 (± 14.4) 1.47 [0.99 to 1.02]; P = 0.142 -
Male sex, n (%) 36 (69%) 39 (64%) 0.85 [0.51 to 1.44]; P = 0.551 -
SAPS II 31.4 (± 10.9) 46.3 (± 18.2) 1.05 [1.03 to 1.06]; P <0.001 Not included
Immunosuppression/cancer, n (%) 20 (38%) 30 (49%) 1.30 [0.79 to 2.16]; P = 0.169 -
Cancer, n (%) 0 (0%) 8 (13%) 4.36 [2.01 to 9.44]; P <0.001 2.74 [1.22 to 6.15]; P= 0.014
At Admission before VNI     
Sepsis, n (%) 37 (71%) 43 (70%) 0.97 [0.56 to 1.68]; P = 0.913 -
Glasgow coma score 14.9 (± 0.5) 14.6 (± 1.2) 0.84 [0.69 to 1.03]; P = 0.098 0.77 [0.63 to 0.96]; P= 0.018
Respiratory Rate, breaths/minute 32.7 (± 7.0) 33.3 (± 6.6) 1.01 [0.97 to 1.05]; P = 0.517 -
pH 7.44 (± 0.06) 7.44 (± 0.08) 2.16 [0.05 to 89.3]; P = 0.685 -
PaO2, mm Hg 78.7 (± 43.0) 84.1 (± 53.2) 1.00 [0.99 to 1.01]; P = 0.442 -
PaCO2, mm Hg 34.8 (± 5.6) 35.3 (± 6.0) 1.01 [0.97 to 1.06]; P = 0.669 -
Bicarbonates, mmol/L 24.4 (± 4.8) 25.5 (± 5.0) 1.01 [0.96 to 1.06]; P = 0.547 -
Lactates, mmol/L 2.0 (± 1.8) 1.9 (± 1.2) 1.00 [0.85 to 1.18]; P = 0.940 -
Heart rate, beats/minute 114 (± 27) 110 (± 25) 0.99 [0.98 to 1.01]; P = 0.467 -
Shock, n (%) 4 (8%) 14 (23%) 2.08 [1.14 to 3.79]; P = 0.017 1.89 [1.01 to 3.53]; P= 0.047
Systolic arterial pressure, mmHg 134 (± 27) 124 (± 24) 0.99 [0.98 to 1.00]; P = 0.055 Not included
At NIV initiation     
Altered consciousness, n (%) 3 (6%) 8 (13%) 1.71 [0.81 to 3.59]; P = 0.158 -
pH 7.43 (± 0.06) 7.41 (± 0.10) 0.12 [0.00 to 4.31]; P = 0.244 -
PCO2, mm Hg 36.6 (± 6.7) 37.5 (± 7.5) 1.02 [0.98 to 1.05]; P = 0.327 -
PaO2/FiO2, mm Hg 211 (± 86) 163 (± 92) 0.99 [0.99 to 0.99]; P = 0.003 Not included
Moderate or severe ARDS, n (%) 21 (40%) 45 (74%) 2.79 [1.57 to 4.95]; P < 0.001 2.57 [1.33 to 4.75]; P= 0.003
PaO2/FiO2 <150 mm Hg, n (%) 12 (23%) 37 (61%) 2.97 [1.77 to 4.99]; P < 0.001 Not included
PEEP level, cm H2O 4.8 (± 1.0) 4.4 (± 1.3) 0.77 [0.62 to 0.94]; P = 0.011 0.71 [0.57 to 0.88]; 0.002
PS level, cm H2O 8.1 (± 2.2) 8.0 (± 1.9) 0.98 [0.86 to 1.13]; P = 0.915 -
Tidal volume, ml 576 (± 144) 619 (± 196) 1.00 [0.99 to 1.00]; P = 0.157 -
Respiratory rate, breaths/minute 32.7 (± 12.9) 33.9 (± 9.0) 1.01 [0.98 to 1.03]; P = 0.601 -
Important leaks, n (%) 2/43 (5%) 3/48 (6%) 1.39 [0.43 to 4.48]; P = 0.720 -
Poor tolerance, n (%) 3/43 (7%) 9/48 (19%) 2.08 [1.00 to 4.30]; P = 0.049 1.97 [0.89 to 4.30]; P = 0.09
  1. Values are given as mean (± standard deviation) or proportion (%).
  2. AHRF, Acute Hypoxemic Respiratory Failure; ARDS, Acute Respiratory Distress Syndrome; CI, 95% Confidence Interval HR; Hazard Ratio (aHR, adjusted HR); NIV, Non-Invasive Ventilation; PEEP, Positive End-Expiratory Pressure; PS, Pressure Support; SAPS II, Simplified Acute Physiology Score; VT, Tidal Volume.