Outcomes of post-cardiac surgery patients with persistent hyperlactatemia in the intensive care unit: a matched cohort study

Table 1 Comparison of demographics and perioperative course of cases and controls

	Cases (n = 144)	Controls (n = 280)	p-value
Preoperative characteristics
Gender (male)	93 (64.6 %)	181 (64.6 %)	1.00
Age (years)	70 (43–89)	70 (42–89)	0.81
Parsonnet score	18.3 (0–49.0)	16.5 (0–52.5)	0.28
Renal failure^a	22 (15.3 %)	29 (10.4 %)	0.16
Severe peripheral vascular disease	13 (9 %)	17 (6.1 %)	0.32
Cardiogenic shock^b	5 (3.5 %)	1 (0.4 %)	0.02
Preoperative intra-aortic balloon pump	16 (11.1 %)	10 (3.6 %)	0.004
Chronic obstructive pulmonary disease^c	10 (6.9 %)	48 (17.1 %)	0.004
Diabetes^d	38 (26.4 %)	103 (36.8 %)	0.04
Postoperative characteristics
Peak lactate (mmol/L)	4.6 (3.0–18.0)	2.1 (0.8–2.9)	<0.0001
Peak serum creatinine level (mmol/L)	127 (66–840)	100 (39–1013)	<0.0001
Intra-aortic balloon pump	29 (20.1 %)	14 (5 %)	<0.0001
Computed tomography chest /abdomen	4 (2.8 %)	0	0.01
Return to operating room	22 (15.3 %)	5 (1.8 %)	<0.0001
Cardiogenic shock	9 (6.3 %)	2 (0.7 %)	0.002
Post-operative cardiac hemorrhage	9 (6.3 %)	4 (1.4 %)	0.01
Acute kidney injury (AKIN 1)	68 (50.4 %)	73 (26.8 %)	<0.0001
Ischemic bowel	1 (0.7 %)	0	0.34
Length of ICU admission (days)	3 (1–96)	1 (1–29)	<0.0001
ICU readmission	12 (8.3 %)	13 (4.7 %)	0.13
Mechanical ventilation (days)	0.89 (0.14–75.5)	0.50 (0.09–11.9)	<0.0001
Mortality	15 (10.4 %)	4 (1.4 %)	<0.0001

Cases presented with peak lactate ≥3.0 mmol/L in the postoperative ICU admission while controls had a peak lactate <3.0 mmol/L. Data is expressed as: number of patients (frequency in percentage) or median (range)
^aAcute or chronic renal failure
^bWith urinary output <10 cc/hr
^cChronic obstructive pulmonary disease on medical treatment
^dDiabetes on insulin or oral hypoglycemic agents

ISSN: 1749-8090