Noninvasive ventilation vs. high-flow nasal cannula oxygen for preoxygenation before intubation in patients with obesity: a post hoc analysis of a randomized controlled trial

Annals of Intensive Care

Table 2 Baseline characteristics of obese patients with obesity according to the strategy of preoxygenation

	Non-invasive ventilation (n = 40)	High-flow nasal cannula oxygen (n = 51)	P value
Demographic characteristics
Age, year, mean ± SD	66 ± 12	66 ± 16	0.85
Male sex, n (%)	29 (73)	35 (69)	0.69
Body mass index,^a kg·m⁻², mean ± SD	35 ± 5	34 ± 4	0.28
SAPS II^b, point, mean ± SD	50 ± 21	49 ± 17	0.86
Reason for ICU admission			0.98
Respiratory primary failure, n (%)
Respiratory infection	12	16
COPD exacerbation	4	4
Extra-pulmonary ARDS	2	1
Pulmonary atelectasis	1	1
Other	3	3
Non-respiratory primary failure, n (%)
Shock	8	11
Cardiogenic pulmonary edema	1	3
Neurologic	4	3
Other	4	8
Post-operative, n (%)	1	1
Clinical characteristics
Oxygen device the last hour before inclusion, n (%)			0.17
Standard oxygen	19 (47)	19 (37)
High-flow nasal cannula oxygen	14 (35)	14 (27)
Non-invasive ventilation	7 (18)	18 (35)
Vasopressor support at inclusion, n (%)	7 (18)	12 (24)	0.48
Bilateral pulmonary infiltrates, n (%)	22 (65)	32 (76)	0.27
Respiratory variables
Respiratory rate, breaths/min	30 ± 7	30 ± 8	0.71
PaO₂/FIO₂ ratio, mm Hg	149 ± 65	154 ± 66	0.72
MACOCHA score, ^c n (%)			0.36
< 3	28 (70)	40 (78)
≥ 3	12 (30)	11 (22)
Cormack III or IV, ^d n (%)	(1, 2)9 (23)	6 (12)	0.17

COPD chronic obstructive pulmonary disease, SD standard deviation
^aThe body mass index is the weight in kilograms divided by the square of the height in meters
^bThe Simplified Acute Physiology Score (SAPS) II is calculated from 17 variables at inclusion, information about previous health status, and from information obtained at admission. Scores can range from 0 to 163, with higher scores indicating more severe disease
^cMACOCHA is calculated from 7 variables including Mallampati score III or IV, apnoea syndrome, cervical spine limitation, opening mouth less than 3 cm, coma, hypoxia, non-trained operator. Score range from 0 to 12 points, with higher scores indicating risk of difficult intubation
^dCormack grade III, if no part of the glottis can be seen, but only the epiglottis, grade IV, if not even the epiglottis can be exposed