Table 1.

Perioperative characteristics of the patients

Variables	Phase 1 (n=25)	Phase 2
		Traditional ventilation (n=32)	Protective ventilation (n=32)	P (within phase 2)
Age (years)	68.6±7.6	69.9±6.8	70.3±6.4	0.441
Range	60–84	60–83	60–82
Weight (kg)	67.8±9.0	64.2±9.1	63.1±9.1	0.242
BMI (kg/m2)	23.5±2.7	22.6±3.1	22.5±2.6	0.274
Range	17.0–28.7	17.1–29.9	17.0–28.3
PBW (kg)	65.2±4.5	65.1±5.0	62.8±5.6	0.233
ASA grade
II	24 (96%)	30 (93.8%)	30 (93.8%)	0.918
III	1 (4%)	2 (6.3%)	2 (6.3%)	0.918
LVEF (%)	66.3±5.4	68.5±7.3	65.6±7.6	0.208
Hypertension	17 (68%)	18 (56.3%)	15 (46.9%)	0.280
Diabetes mellitus	7 (28%)	5 (15.6%)	4 (12.5%)	0.309
Coronary disease	0	2 (6.3%)	1 (3.1%)	0.429
Cerebral infarction	1 (4%)	2 (6.3%)	1 (3.1%)	0.828
Smoking history				0.458
Never	14 (56.0%)	23 (71.9%)	21 (65.6%)
Former	4 (16.0%)	3 (9.4%)	4 (12.5%)
Current	7 (28.0%)	6 (18.7%)	7 (21.9%)
Operation time (min)	184.3±64.4	183.2±64.7	175.4±52.6	0.843
Postoperative hospital stay (days)		8.3±3.9	9.3±3.7	0.494
Estimated blood loss (ml)	138 (30–600)	89 (50–300)	100 (50–250)	0.249
Fluids (ml)	1790 (1200–3250)	1616 (1200–2800)	1605 (1100–2250)	0.314
Need for vaspressors (n)a	10 (40%)	12 (37.5%)	10 (31.3%)	0.772
Ephedrine total dose (mg)b	7.3±2.6	6.6±1.9	7.3±2.6	0.809
Phenylephrine total dose (ug)c	83.3±57.7	87.5±47.9	75.0±50.0	0.998
Duration of CO2 pneumoperitoneum (min)	135±58	143±56	129±43	0.686

BMI Body mass index, PBW Predicted body weight, ASA American Society of Anesthesiologists, LVEF Left ventricular ejection fraction

^aNumber of patients who received ephedrine or phenylephrine

^bEphedrine dose represents the mean from patients who received ephedrine

^cPhenylephrine dose represents the mean from patients who received phenylephrine