Table 1.

Patient characteristics.

Patient characteristicsa	Pre-LDHS patients (n = 41)	Post-LDHS patients (n = 30)	pvalue
Age (years)	54 (46, 68)	61 (53, 68)	0.24
Male, n (%)	25 (61)	18 (60)	1
BMI ≥30 kg/m2, n (%)	17 (41)	17 (57)	0.24
Smoker, n (%)			0.32
Never smoker	30 (73)	18 (60)
Current smoker	5 (12)	3 (10)
Past smoker	6 (15)	9 (30)
History of thrombosis, n (%)	5 (12)	0 (0)	0.07
Patients with thrombosis risk factors, n (%)	27 (66)	17 (57)	0.47
Obesity	19 (46)	14 (47)
Diabetes	16 (39)	10 (33)
Malignancy	5 (12)	2 (7)
Hospitalized in 30 days prior to admission, n (%)	0 (0)	1 (3)	0.42
Surgery in 30 days prior to ICU admission, n (%)	1 (2)	2 (7)	0.57
Systemic anticoagulation, n (%)	13 (32)	14 (47)	0.32
Heparin	12 (92)	12 (86)
Enoxaparin	1 (8)	2 (14)
SOFA scoreb	7 (5,9)	6 (3,10)	0.67
Arterial lines prior to index arterial line	1 (1,1)	1 (1,2)	0.30
Arterial line placed by procedure service, n (%)	27 (66)	24 (80)	0.19
Location of index arterial line, n (%)
Radial	38 (93)	26 (87)	0.45
Femoral	2 (5)	2 (7)	1
Brachial	1 (2)	1 (3)	1
Axillary	0 (0)	1 (3)	0.42
Baseline laboratory values
INR	1.2 (1.1, 1.2)	1.2 (1.1, 1.3)	0.88
PTT (seconds)	34 (30, 40)	36 (31, 44)	0.29
Fibrinogen (mg/dL)	716 (632, 855)	744 (606, 883)	0.87
Anti-Xac (IU/mL)	0.66 (0.53, 0.79)	0.46 (0.23, 0.59)	0.14
Platelets (K/uL)	287 (214, 348)	279 (198, 360)	0.99
CRP (mg/L)	158 (139, 285)	146 (120, 190)	0.16
D-Dimer (ng/mL)	2396 (1685, 5061)	2667 (1259, 4371)	0.74
Ferritind (mcg/L)	896 (475, 1299)	1625 (860, 2917)	0.02

Abbreviations: BMI = Body Mass Index; ICU = Intensive Care Unit; IQR = Interquartile Range; LDHS = Low Dose Heparinized Saline; SOFA = Sequential Organ Failure Assessment.

^aData presented as median (interquartile range) unless otherwise stated.

^bAt protocol start for heparin patients and at index arterial line for pre-LDHS patients.

^cPatients on systemic enoxaparin versus heparin often had different anti-Xa goals.

^dStatistically significant at p < 0.05.