Hypotension after intensive care unit drop-off in adult cardiac surgery patients

Table 1 Basic demographics of the study population, n (%)

Basic demographics	Overall	ICU hypotension
Total	417	227
Sex
Male	305 (73)	172 (76)
Female	112 (27)	55 (24)
Median age (IQR)	67 (59, 73)	67 (58, 74)
Race
Not disclosed	9 (2)	5 (2)
White	356 (85)	197 (87)
Other	52 (13)	25 (11)
Median BMI (IQR)	28 (25, 32)	29 (26, 33)
Mortality
Alive	405 (97)	217 (96)
Dead	12 (3)	10 (4)
Type of surgery
Aortic graft	21 (5)	11 (5)
CABG	193 (46)	113 (50)
Ventriculomyotomy	26 (6)	9 (4)
Valve	122 (29)	63 (28)
Aortic graft + CABG	3 (0.7)	1 (0.4)
Valve + CABG	30 (7)	23 (10)
ASD repair	7 (2)	4 (2)
Aortic graft + valve	12 (3)	2 (1)
ASD repair + valve	3 (0.7)	1 (0.4)
Need or surgery
Elective	318 (76)	175 (77)
Urgent/emergent	99 (24)	52 (23)
Comorbidities
CAD	278 (67)	164 (72)
Afib	81 (19)	42 (19)
AICD/PM	21 (5)	11 (5)
DM	137 (33)	89 (39)
PHTN	21 (5)	13 (6)
LD	27 (7)	18 (8)
KI	88 (21)	53 (23)
Active IE	6 (1)	2 (1)
IS	16 (4)	10 (4)

ICU: Intensive care unit; IQR: Interquartile range; BMI: Body mass index; CABG: Coronary artery bypass graft; ASD: Atrial septum defect; CAD: Coronary artery disease; Afib: Atrial fibrillation; AICD/PM: Automatic implantable cardioverter defibrillator/pacemaker; DM: Diabetes mellitus; PHTN: Pulmonary hypertension; LD: Liver disease; KI: Kidney injury; IE: Infective endocarditis; IS: Immunosuppressed.

Table 2 Association of baseline characteristics with intensive care unit hypotension and mortality

Baseline characteristic	ICU hypotension, n = 227	No ICU hypotension, n = 190	P value	Alive, n = 405	Dead, n = 12	P value
Age, median (IQR)	67 (58, 74)	68 (59, 73)	0.73	67 (59, 73)	64 (59, 67)	0.42
Male sex, n (%)	172 (76)	133 (70)	0.22	299 (74)	6 (50)	0.0935
BMI, median (IQR)	29 (26, 33)	27 (25, 31)	0.01	28 (25, 32)	32 (27, 38)	0.039
CAD, n (%)	164 (72.2)	114 (60.0)	0.009	272 (67)	6 (50)	0.23
DM, n (%)	89 (39.2)	48 (25.3)	0.003	133 (33)	4 (33)	1.0
Afib, n (%)	42 (19)	39 (21)	0.62	78 (19)	3 (25)	0.71
AICD/PM, n (%)	11 (5)	10 (5)	1.00	20 (5)	1 (8)	0.47
PHTN, n (%)	13 (6)	8 (4)	0.51	18 (12)	3 (25)	0.018
IE, n (%)	2 (1)	4 (2)	0.42	6 (1)	0 (0)	1.0
LD, n (%)	18 (8)	9 (5)	0.23	27 (7)	0 (0)	1.0
KD, n (%)	53 (23)	35 (18)	0.23	86 (21)	2 (17)	0.78
IS, n (%)	10 (4)	6 (3)	0.61	16 (4)	0 (0)	1.0
Elective surgery, n (%)	175 (77)	143 (75)	0.73	309 (76)	9 (75)	1.0
ASA, n (%)			0.42			0.02
2	1 (0.5)	1 (0.4)		2 (0.5)	0 (0)
3	94 (49)	94 (41)		186 (46)	2 (17)
4	94 (49)	130 (57)		215 (53)	9 (75)
5	1 (0.5)	2 (0.9)		2 (0.5)	1 (8)
EF%, median (IQR)	60 (51, 64)	62 (54, 66)	0.29	60 (53, 65)	62 (53, 67)	0.62
BT, median (IQR)	117 (90, 150)	114 (85, 148)	0.10	115 (89, 148)	152 (108, 240)	0.0008
CCT, median (IQR)	81 (60, 105)	77 (53, 108)	0.10	80 (55, 105)	111 (59, 160)	0.018
Transfusion, n (%)	138 (61)	124 (65)	0.36	252 (62)	10 (83)	0.22
Pressors, n (%)	178 (78)	138 (73)	0.21	305 (75)	11 (92)	0.31
Bolus given, n (%)	125 (59.0)	87 (41.0)	0.06	203 (50)	9 (75)	0.14
Hb, median (IQR)	13 (12,14)	13 (12, 14)	0.79	13 (12, 14)	13 (10, 14)	0.48
Hct, median (IQR)	40 (35, 42)	40 (36, 42)	0.86	40 (36, 42)	40 (33, 44)	0.73
PLT, median (IQR)	203 (163, 248)	198 (159, 233)	0.18	201 (161, 243)	186 (155, 236)	0.69
Cre, median (IQR)	1.1 (0.9, 1.4)	1 (0.9, 1.2)	0.13	1 (0.9, 1.3)	1.1 (0.9, 1.9)	0.80
Ca, median (IQR)	9.3 (8.9, 9.6)	9.3 (8.9, 9.6)	0.78	9.3 (8.9, 9.6)	9.2 (8.6, 9.4)	0.49
Pre-op SBP, median (IQR)	125 (110, 139)	126 (110, 139)	0.69	126 (110, 139)	114 (98, 144)	0.18
Pre-op MAP, median (IQR)	84 (73, 94)	83 (74, 96)	0.89	84 (74, 95)	80 (49, 91)	0.066

ICU: Intensive care unit; IQR: Interquartile range; n: Number of patients; BMI: Body mass index; CAD: Coronary artery disease; DM: Diabetes mellitus; Afib: Arterial fibrillation; AICD/PM: Automatic implantable cardioverter defibrillator/pacemaker; PHTN: Pulmonary hypertension; IE: Infective endocarditis; LD: Liver disease; KD: Kidney disease; IS: Immunosuppressed; ASA: American Society of Anesthesiologists; EF: Ejection fraction; BT: Bypass time; CCT: Cross-clamp time; Hb: Hemoglobin; Hct: Hematocrit; PLT: Platelet; Cre: Creatinine; Ca: Calcium; pre-op: Pre-operation; SBP: Systolic blood pressure; MAP: Mean arterial pressure.

Table 3 Unadjusted association of intensive care unit hypotension with clinical outcomes

Item	ICU hypotension	No ICU hypotension	P value
Hosp. LOS, median (IQR)	7 (5, 10)	7 (5, 9)	0.49
ICU LOS, median (IQR)	2 (1, 4)	2 (1, 3)	0.21
MV hours, median (IQR)	5 (3, 15)	4 (3, 6)	< 0.001
Hosp. mortality, n (%)	10 (4.4)	2 (1.1)	0.07

ICU: Intensive care unit; Hosp: Hospital; LOS: Length of stay; IQR: Interquartile range; MV: Mechanical ventilation.

Table 4 Multivariate analysis for intensive care unit hypotension

Item	ICU hypotension
	OR; 95%CI	P value
BMI	1.02; 0.99-1.07	0.13
CAD	1.69; 1.09-2.62	0.018
DM	1.66; 1.06-2.61	0.025
BT	1.004; 1.0002-1.008	0.034
Bolus	1.2; 0.79-1.82	0.38

Cross clamp time excluded because of linear correlation with bypass time. ICU: Intensive care unit; OR: Odds ratio; CI: Confidence interval; BMI: Body mass index; CAD: Coronary artery disease; DM: Diabetes mellitus; BT: Bypass time.

Table 5 Multivariate analysis for mortality

Item	Mortality
	OR; 95%CI	P value
Sex	0.74; 0.06-7.99	0.80
BMI	0.93; 0.76-1.14	0.51
ICU hypotension	0.27; 0.03-2.74	0.27
Lowest MAP (pre-op)	0.96; 0.89-1.02	0.19
BT	1.01; 0.43-23.8	0.33
ASA	3.19; 0.79-1.82	0.26

Cross clamp time excluded because of linear correlation with bypass time; Pulmonary hypertension (low frequency) excluded to prevent overfitting). OR: Odds ratio; CI: Confidence interval; BMI: Body mass index; ICU: Intensive care unit; MAP: Mean artery pressure; pre-op: Pre-operative; BT: Bypass time; ASA: American Society of Anesthesiologists.