Table 3.

Maintenance anesthetic gas information for baseline and intervention periods

	Baseline	Intervention	Difference (95% CI)
Desflurane
n cases	17,472 (93.6%)	1,185 (6.4%)
Duration (hours)	2.5 ± 1.9	2.3 ± 1.9	−0.2 (−0.3, −0.1)
Fresh Gas Flow (L/minute)	1.3 ± 0.5	0.9 ± 0.4	−0.3 (−0.4, −0.3)
Mean End-tidal Agent Concentration (volume %)	4.1 ± 1.7	3.4 ± 1.7	−0.7 (−0.8, −0.6)
MAC	0.7 ± 0.3	0.6 ± 0.3	−0.1 (−0.1, −0.1)
Total mL/hour	18.8 ± 11.0	12.3 ± 8.3	−6.5 (−7.1, −5.9)
mL/MAC-hour	28.3 ± 13.4	23.0 ± 14.6	−5.4 (−6.2, −4.6)
$/MAC-hour	$17.01 ± $8.05	$13.79 ± $8.79	−$3.22 (−$3.70, −$2.74)
Sevoflurane
n cases	44,899 (62.5%)	26,911 (37.5%)
Duration (hours)	2.0 ± 1.7	2.1 ± 1.8	0.1 (0.1 to 0.1)
Fresh Gas Flow (L/minute)	2.0 ± 0.6	1.2 ± 0.5	−0.8 (−0.8, −0.8)
Mean End-tidal Agent Concentration (volume %)	1.6 ± 0.6	1.5 ± 0.5	−0.1 (−0.1, −0.1)
MAC	0.9 ± 0.3	0.9 ± 0.3	0.0 (−0.1, 0.0)
Total mL/hour	13.8 ± 6.8	8.2 ± 4.8	−5.5 (−5.6, −5.4)
mL/MAC-hour	14.5 ± 5.3	9.3 ± 6.9	−5.2 (−5.3, −5.1)
$/MAC-hour	$5.82 ± $2.11	$3.72 ± $2.77	−$2.10 (−$2.13, −$2.06)

Data are mean ± SD or n(%)

All relevant values are weighted according the length/amount of data.

“Maintenance” is defined as procedure start to procedure end.

CI, confidence interval; MAC, minimum alveolar concentration

Baseline period was from July 22, 2015 to July 10, 2018. Intervention was implemented on August 29, 2018. Data during the transition period (July 11, 2018 to August 28, 2018) were excluded.