Adequate Oxygenation State Maintained during Electroconvulsive Therapy in Nonobese Patients Using the Oxygen Reserve Index: A Pilot Study

Table 1

Time course of changes in ORi and SpO₂ between the three groups.

	①	②	③	④	⑤	⑥	⑦
ORi
No preoxygenation	0	NA	NA	0.52 ± 0.07	0.42 ± 0.16	0.38 ± 0.18	0.31 ± 0.06
One minute	0	0.11 ± 0.24	0.27 ± 0.36	0.49 ± 0.26	0.44 ± 0.24	0.40 ± 0.22	0.36 ± 0.28
Three minutes	0	0.10 ± 0.23	0.38 ± 0.32	0.60 ± 0.26	0.61 ± 0.26	0.44 ± 0.31	0.43 ± 0.30
SpO2 (%)
No preoxygenation	95 ± 1.0	NA	NA	99 ± 0.6	99 ± 0	98 ± 0.5#	98 ± 0.6
One minute	95 ± 1.9	96 ± 1.8	98 ± 1.6	99 ± 0.9	99 ± 0.9	98 ± 1.5	98 ± 1.4
Three minutes	95 ± 1.4	97 ± 1.0	99 ± 1.0	99 ± 0.7	99 ± 0.5	99 ± 1.1	99 ± 0.7

Data are expressed as mean ± SD. ORi: oxygen reserve index; NA: not assigned. One minute: one minute of preoxygenation before induction of anesthesia. Three minutes: three minutes of preoxygenation before induction of anesthesia. ① Before preoxygenation; ② thirty seconds after starting oxygenation; ③ one minute after starting oxygenation; ④ before cessation of manual mask ventilation; ⑤ before restarting manual mask ventilation; ⑥ at time of restarting spontaneous breathing; ⑦ full recovery of spontaneous breathing. compared with the other two groups. compared with the preoxygenation period.