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Table 2 Primary and secondary outcomes, according to the study group

From: Early nasal high-flow versus Venturi mask oxygen therapy after lung resection: a randomized trial

Outcome Study group p value Odds ratio or mean difference (95% CI)
HFNC
(n = 47)
Venturi mask
(n = 48)
Primary outcome
 Incidence of postoperative hypoxemia (PaO2/FiO2 < 300 mmHg)
  Unadjusted analysis    0.84 1.11 (0.41–3)
   No. of patients 38 38   
   % of patients (95% CI) 81 (69–93) 79 (67–91)   
Secondary outcomes
 Need for supplemental oxygen after treatment discontinuation
  Unadjusted analysis    0.48 1.34 (0.60–3)
   No. of patients 24 21   
   % of patients (95% CI) 51 (36–66) 44 (29–58)   
 Incidence of postoperative respiratory failure requiring ventilatory support*
  Unadjusted analysis    > 0.999 0.67 (0.11–4.18)
   No. of patients 2 3   
   % of patients (95% CI) 4 (0–11) 6 (0–13)   
 Incidence of postoperative pulmonary complications
  Unadjusted analysis    0.64 1.29 (0.51–3.25)
   No. of patients 13 11   
   % of patients (95% CI) 28 (14–41) 23 (11–35)   
Mean dyspnea during the first 4 postoperative days
 ANOVA for repeated measures    0.97 0 (− 1–1)
  Mean 2.2 2.3   
  95% CI 1.5–2.9 1.5–3   
Other secondary outcomes
 Incidence of moderate-to-severe postoperative hypoxemia (PaO2/FiO2 < 200 mmHg)
  Unadjusted analysis    0.67 1.24 (0.54–2.88)
   No. of patients 18 16   
   % of patients (95% CI) 38 (24–53) 33 (20–47)   
 Incidence of postoperative hypercapnia (PaCO2 > 45 mmHg)
  Unadjusted analysis    0.004 0.24 (0.09–0.63)
   No. of patients 8 22   
   % of patients (95% CI) 17 (6–28) 46 (31–60)   
  Adjusted analysis¶    0.002 0.18 (0.06–0.54)
Mean PaO2/FiO2
 In the first four postoperative days
  ANOVA for repeated measures    0.92 1 (− 30–33)
   Mean 300 299   
   95% CI 279–322 276–322   
 During assigned treatments (two postoperative days)
  ANOVA for repeated measures    0.72 5 (− 24–35)
   Mean 301 296   
   95% CI 281–321 274–317   
Mean PaCO2
 In the first four postoperative days
  ANOVA for repeated measures    0.015 − 1.7 (− 3 to − 0.3)
   Mean 38.9 40.6   
   95% CI 38–39.8 39.6–41.5   
During assigned treatments (two postoperative days)
 ANOVA for repeated measures
   Mean 39.7 41.6 0.009 − 2 (− 3.4 to − 0.5)
   95% CI 38.7–40.6 40.5–42.7   
Incidence of overall postoperative complications
 Unadjusted analysis    0.61 1.25 (0.53–2.98)
  No. of patients 16 14   
  % of patients (95% CI) 34 (20–48) 29 (16–43)   
Length of hospital stay, days
 Unadjusted analysis    0.83 − 2 (− 8–4)
  Median 6 6   
  Interquartile range 5–7 5–7   
28-day mortality
 Unadjusted analysis    n/a  
  No. of patients 0 0   
  1. ¶The analysis was adjusted for age, history of clinically documented pulmonary infections in the month preceding surgery and preoperative PaCO2
  2. *Four patients needed NIV (three patients in the Venturi mask group and one in the HFNC group) and two patients underwent endotracheal intubation (one in each group)