Relevant clinical factors for early extubation in living-donor liver transplantation: A single-center retrospective cohort study

Table 1 Comparison of preoperative characteristics between the delayed and early extubation group, n (%)

Variables	Whole group (n = 159)			Subgroup (n = 67)
	Delayed extubation (n = 66)	Early extubation (n = 93)	P value	Delayed extubation (n = 20)	Early extubation (n = 47)	P value
Age (year)	53.4 (8.2)	54.9 (7.5)	0.246	55.1 (7.1)	55.0 (8.2)	0.965
Sex (male)	49 (74.2)	70 (75.3)	> 0.999	16 (80.0)	39 (83.0)	0.741
ASA	-	-	0.163	-	-	0.527
II	18 (27.3)	14 (15.1)	-	7 (35.0)	12 (25.5)	-
III	39 (59.1)	65 (69.9)	-	12 (60.0)	29 (61.7)	-
IV	9 (13.6)	14 (15.1)	-	1 (5.0)	6 (12.8)	-
Height (cm)	165.9 (8.2)	165.5 (7.9)	0.755	166.4 (8.9)	165.7 (7.3)	0.752
Weight (kg)	64.7 (12.5)	63.3 (10.5)	0.439	66.1 (11.0)	64.4 (9.1)	0.499
BMI (kg/m2)	23.4 (3.4)	23.0 (2.7)	0.430	23.8 (3.0)	23.4 (2.4)	0.528
Malnutrition (BMI < 18.5)	5 (7.6)	8 (8.6)	> 0.999	0 (0.0)	2 (4.3)	> 0.999
Obesity (BMI > 30)	3 (4.5)	1 (1.1)	0.308	1 (5.0)	1 (2.1)	0.511
Etiology
Viral	43 (65.2)	71 (76.3)	0.172	13 (65.0)	39 (83.0)	0.121
Alcoholic	20 (30.3)	19 (20.4)	0.215	4 (20.0)	6 (12.8)	0.470
Malignancy	40 (60.6)	59 (63.4)	0.844	16 (80.0)	35 (74.5)	0.760
Autoimmune	1 (1.5)	1 (1.1)	> 0.999	1 (5.0)	0 (0.0)	0.299
Others	4 (6.1)	5 (5.4)	> 0.999	1 (5.0)	2 (4.3)	> 0.999
MELD score	15.0 (7.0-23.0)	10.0 (8.0-16.0)	0.113	7.5 (7.0-11.8)	8.0 (7.0-10.0)	0.418
Functional capacity ≥ 4 METs	24 (36.4)	38 (40.9)	0.683	12 (60.0)	23 (48.9)	0.574
Preoperative cardiac echo findings
LVEF (%)	67.0 (63.0-70.3)	66.0 (63.3-69.0)	0.515	64.5 (62.3-68.5)	67.0 (64.0-69.3)	0.149
Pulmonary hypertension	4 (6.1)	4 (4.4)	0.721	0 (0.0)	1 (2.1)	> 0.999
Comorbidity
Preoperative RRT	4 (6.1)	2 (2.2)	0.234	1 (5.0)	0 (0.0)	0.299
Hypertension	11 (16.7)	19 (20.4)	0.695	5 (25.0)	12 (25.5)	> 0.999
Diabetes mellitus	18 (27.3)	35 (37.6)	0.232	5 (25.0)	13 (27.7)	> 0.999
Cerebro-cardiovascular disease	0 (0.0)	2 (2.2)	0.511	0 (0.0)	1 (2.1)	> 0.999
Preoperative delirium	8 (12.1)	2 (2.2)	0.017	0 (0.0)	0 (0.0)	N/A
Hepatopulmonary syndrome	11 (16.7)	13 (14.0)	0.854	2 (10.0)	4 (8.7)	> 0.999
West-Haven criteria on encephalopathy	-	-	0.234	-	-	> 0.999
Grade 0-1	62 (93.9)	91 (97.8)	-	20 (100.0)	46 (97.9)	-
Grade 2	4 (6.1)	2 (2.2)	-	0 (0.0)	1 (2.1)	-
Grade 3-4	0 (0.0)	0 (0.0)	-	0 (0.0)	0 (0.0)	-
Baseline laboratory findings
PaO2/FiO2 ratio	306.0 (254.3-409.8)	333.0 (275.5-411.8)	0.253	322.5 (271.3-406.8)	365.0 (287.0-434.0)	0.276
Hemoglobin (g/dL)	11.3 (2.3)	11.4 (2.4)	0.732	12.9 (2.2)	12.3 (2.4)	0.347
Platelets (103/μL)	64.0 (41.0-99.5)	77.0 (52.0-119.2)	0.191	110.5 (98.0-157.3)	113.0 (85.0-148.0)	0.337
PT-INR	1.4 (1.2-1.7)	1.3 (1.2-1.5)	0.003	1.2 (1.1-1.2)	1.2 (1.1-1.3)	0.962
aPTT (second)	48.4 (39.4-56.4)	41.0 (37.5-47.3)	0.002	38.6 (34.7-43.9)	38.3 (35.3-42.4)	0.784
Ammonia (μmol/L)	36.0 (25.8-49.5)	34.0 (23.0-49.0)	0.355	31.5 (23.3-36.8)	26.0 (20.0-41.0)	0.661
Bilirubin (mg/dL)	2.4 (1.4-4.3)	1.4 (1.1-2.6)	< 0.001	1.5 (1.0-2.2)	1.2 (0.9-1.5)	0.081
Albumin (g/dL)	3.1 (0.5)	3.2 (0.5)	0.518	3.5 (0.5)	3.3 (0.5)	0.314
Glucose (g/dL)	117.0 (104.0-134.3)	120.0 (105.8-140.8)	0.446	123.5 (105.5-159.3)	120.0 (106.0-141.0)	0.627
Creatinine (mg/dL)	0.8 (0.6-0.9)	0.7 (0.6-0.9)	0.306	0.8 (0.6-0.9)	0.7 (0.6-0.8)	0.497
SBP, baseline (mmHg)	128.0 (115.3-139.0)	128.0 (116.8-147.0)	0.437	131.5 (120.0-144.5)	137.0 (120.0-148.0)	0.330
HR, baseline (beats/minute)	78.0 (68.0-89.3)	80.5 (66.8-91.8)	0.719	72.0 (67.0-85.8)	80.0 (65.0-95.0)	0.388

Data are presented as mean, median, and absolute numbers (%). ASA: American Society of Anesthesiologists; BMI: Body mass index; MELD: Model for end-stage liver disease; METs: Metabolic equivalents; LVEF: Left ventricular ejection fraction; RRT: Renal replacement therapy; PaO₂/FiO₂ ratio: Baseline partial pressure of arterial oxygen to fractional inspired oxygen fraction ratio; PT-INR: Prothrombin time-international normalized ratio; aPTT: Activated partial thromboplastin time; SBP: Systolic blood pressure; HR: Heart rate; N/A: Not applicable.