TABLE 1.
Clinical Characteristics and Laboratory Measures on Day 0 Grouped by Venous Thromboembolism
| Laboratory Measures | Reference Range | All Patients, n = 98 | VTE, n = 26 | No VTE, n = 72 | p |
|---|---|---|---|---|---|
| Age (yr) | 59 (53–66) | 60.5 (56–63) | 57.5 (51–67) | 0.33 | |
| Sex: male | 75 (76.5) | 21 (80.8) | 54 (75) | 0.79 | |
| Comorbidities | 78 (79.6) | 18 (69.2) | 60 (83.3) | 0.16 | |
| Diabetes | 53 (54.1) | 12 (46.2) | 41 (56.9) | 0.37 | |
| Hypertension | 64 (65.3) | 13 (50) | 51 (70.8) | 0.09 | |
| Heart disease | 20 (20.4) | 1 (3.9) | 19 (26.4) | 0.02 | |
| Chronic kidney disease | 12 (12.2) | 1 (3.9) | 11 (15.3) | 0.17 | |
| Prior transplant | 13 (13.3) | 3 (11.5) | 10 (13.9) | 1.0 | |
| Body mass index (kg/m2) (n = 95) | 32.4 (29.4–38.7) | 32.9 (29.8–36.7) | 32.2 (29.4–39.1) | 0.96 | |
| Anticoagulation | |||||
| Prophylactic | 83 (84.7) | 22 (84.6) | 61 (84.7) | 1.0 | |
| UFH | 21 (25.3) | 8 (36.4) | 13 (21.3) | 0.25 | |
| LMWH | 62 (74.7) | 14 (63.6) | 48 (78.7) | 0.25 | |
| Therapeutic | 14 (14.3) | 4 (15.4) | 10 (13.9) | 1.0 | |
| UFHa | 7 (50) | 3 (75) | 4 (40) | 0.11 | |
| LMWHb | 1 (7.1) | 1 (25) | 0 (0) | 0.11 | |
| Direct oral anticoagulant | 6 (42.9) | 0 (0) | 6 (60) | 0.11 | |
| No anticoagulationc | 1 (1.0) | 0 (0) | 1 (1.4) | 1.0 | |
| Exposure to antiplatelet agent | 23 (23.5) | 3 (11.5) | 20 (27.8) | 0.11 | |
| Aspirin | 16 (69.6) | 3 (100) | 13 (65) | 0.59 | |
| P2Y12 inhibitor | 1 (4.4) | 0 (0) | 1 (5) | 0.59 | |
| Dual antiplatelet therapy | 6 (26.1) | 0 (0) | 6 (30) | 0.59 | |
| Epoprostenol use | 12 (12.2) | 6 (23.1) | 6 (8.3) | 0.08 | |
| Extracorporeal membrane oxygenation (venovenous) | 2 (2.0) | 1 (3.9) | 1 (1.4) | 0.46 | |
| Level of oxygen support | |||||
| Mechanical ventilation | 30 (30.6) | 9 (34.6) | 21 (29.2) | 0.10 | |
| Bilevel positive airway pressure | 27 (27.6) | 11 (42.3) | 16 (22.2) | 0.10 | |
| High-flow nasal cannula oxygen | 31 (31.6) | 4 (15.4) | 27 (37.5) | 0.10 | |
| Low-flow nasal cannula oxygen | 10 (10.2) | 2 (7.7) | 8 (11.1) | 0.10 | |
| Sepsis-related Organ Failure Assessment score | 5 (4–8) | 6 (5–8) | 5 (4–7) | 0.04 | |
| Fibrinogen (mg/dL) (n = 96) | 188–450 | 678 (574.5–843.5) | 583 (452–787) | 688 (604–851) | 0.01 |
| Platelet count (×103/μL) (n =97) | 135–371 | 242 (169–300) | 174 (130–263) | 260 (196–313) | 0.002 |
| Creatinine (mg/dL) | 0.72–1.25 | 0.97 (0.77–1.47) | 0.97 (0.74–1.41) | 0.97 (0.78–1.5) | 0.83 |
| International normalized ratio (n = 96) | 1.2 (1.1–1.3) | 1.2 (1.1–1.3) | 1.2 (1.1–1.3) | 0.94 | |
| Prothrombin time (s) (n = 96) | 11.9–14.5 | 14.6 (14.0–15.7) | 15.1 (14–15.7) | 14.6 (13.9–15.7) | 0.77 |
| Activated partial thromboplastin time (s) (n = 94) | 23.5–33.5 | 31.1 (28.2–35.3) | 30.2 (28.1–35) | 32.2 (28.3–35.4) | 0.73 |
| d-dimer (μg/mL fibrinogen equivalent units) | 0.27–0.49 | 2.16 (0.96–6.81) | 13.5 (1.48–20) | 1.61 (0.80–3.32) | < 0.001 |
| Disseminated intravascular coagulation score (International Society on Thrombosis and Haemostasis) | 2 (2–3) | 3 (2–3) | 2 (0–3) | 0.004 | |
| Thromboelastography (n = 95) | |||||
| Maximum amplitude (mm) | 50–70 | 67 (63.7–70.7) | 62.8 (57.8–67.2) | 68.1 (65–71.6) | < 0.001 |
| Alpha angle (degrees) | 53–72 | 73.2 (68.7–76.4) | 68.2 (63.2–73) | 74.6 (70.6–76.8) | < 0.001 |
| Reaction time (min) | 5–10 | 3.7 (3.2–4.8) | 3.7 (3–4) | 3.8 (3.2–4.8) | 0.44 |
| Shear elastic modulus (complete clot strength) (dyne/cm2)d | 4.5–11 | 10.2 (8.8–12.1) | 8.5 (6.8–10.3) | 10.7 (9.3–12.6) | < 0.001 |
| Clotting index | –3.0 to +3.0 | 3.4 (2.9–3.9) | 2.9 (1.9–3.4) | 3.6 (3.0–4.1) | < 0.001 |
| Percent lysis at 30 min (%) | 0–8 | 0.6 (0–1.4) | 0.9 (0.1–1.6) | 0.5 (0–1.2) | 0.16 |
LMWH = low-molecular-weight heparin (enoxaparin), UFH = unfractionated heparin, VTE = venous thromboembolism.
aTwo patients on venovenous extracorporeal membrane oxygenation, two were started on UFH after being diagnosed with VTE the day of enrollment, two patients were transitioned to UFH to continue home anticoagulation, and one patient was diagnosed with a non-ST-elevation myocardial infarction after enrollment.
bThe patient was initially on therapeutic anticoagulation while awaiting extremity venous duplex ultrasounds that returned as negative the day of ICU admission laboratories. The patient was transitioned back to prophylactic dosing of LMWH and developed an acute pulmonary embolism 26 d later.
cAnticoagulation was held due to a prolonged prothrombin time.
dShear elastic modulus (complete clot strength) = (5,000 × amplitude)/(100–amplitude) with a unit of force represented as dyne/cm2 (1 dyne/cm2 = 0.1 Pa).
Measures represent number (column percent) or median (interquartile range) as appropriate. n = 98 except where noted.
p values from two-sided Mann-Whitney U test for continuous variables and Fisher exact test for categorical variables.