Table 2.

Multivariate logistic regression model for desaturation.

	Odds ratio	95% CI	P value
% VC per 10%	0.885	0.790 to 0.992	0.036
FEV1% per 10%	0.861	0.705 to 1.051	0.140
COPD	2.195	1.088 to 4.428	0.028
Lack of RRa change	1.972	1.226 to 3.172	0.005
Mean perfusion index	0.890	0.781 to 1.014	0.079

% VC: % vital capacity, FEV1%: forced expiratory volume 1.0 (sec) %, COPD: chronic obstructive pulmonary disease, and RRa: acoustic respiratory rate.

Total fluid balance, transfusion requirement, and duration of surgery were excluded from the model during the stepwise backward elimination process.