3.

Ⅱ组患者无通气安全时限的影响因素分析

Contributing factors for safe duration of apnea in patients without preoxygenatoin (Mean±SD, n=38)

	n	Safe time duration for apnea (s)
**P < 0.01, versus body mass index ≥18 and < 25 (kg/m2).
Age (year)
≥ 18 and < 40	11	61.8±6.7
≥40 and ≤60	27	64.3±23.0
Hemoglobin (g/L)
≥90 and < 120	13	66.7±25.3
≥120	25	62.0±16.4
Gender
Male	24	64.6±20.2
Female	14	61.9±19.4
BMI (kg/m2)
≥ 18 and < 25	30	67.4±20.0
≥25 and ≤30	8	49.1±9.9 **
Breath-holding duration (s)
< 60	20	62.7±22.7
≥60	18	64.6±16.2
Smoking
Smokers	7	64.0±20.8
Nonsmokers	31	61.7±14.7