TABLE 1.
Baseline Characteristics and Clinical Outcomes
| Variable | Overall (n = 55) | Bleeding Event (n = 25) | No Bleeding Event (n = 30) | p | Thromboembolic Event (n = 8) | No Thromboembolic Event (n = 47) | p |
|---|---|---|---|---|---|---|---|
| Baseline characteristics | |||||||
| Age (yr), median (interquartile range) | 50.0 (40.0–60.0) | 53.0 (42.0–60.0) | 48.5 (39.0–60.0) | 0.45 | 53.5 (45.5–65) | 48.0 (39.0–60.0) | 0.21 |
| Female, n (%) | 21 (38.2) | 11 (44.0) | 10 (33.3) | 0.42 | 5 (62.5) | 16 (34.0) | 0.24 |
| Simplified Acute Physiology Score-II, median (interquartile range) | 33.0 (24.0–41.0) | 33.0 (28.0–37.0) | 34.5 (21.0–43.0) | 0.98 | 44.5 (35.0–55.5) | 33.0 (22.0–38.0) | 0.01 |
| Body mass index (kg/m2), median (interquartile range) | 30.5 (25.9–37.2) | 32.9 (29.0–36.7) | 29.1 (25.7–37.2) | 0.30 | 29.3 (26.2–36.7) | 31.7 (25.9–37.2) | 0.93 |
| Renal failure requiring continuous renal replacement therapy on ECMO, n (%) | 20 (36.4) | 12 (48.0) | 8 (26.7) | 0.10 | 3 (37.5) | 17 (36.2) | 0.10 |
| Indication for ECMO, n (%) | 0.56 | 0.49 | |||||
| Acute respiratory distress syndrome | 46 (83.6) | 22 (88.0) | 24 (80.0) | 6 (75.0) | 40 (85.1) | ||
| Acute respiratory distress syndrome due to coronavirus disease 2019 | 1 (2.0) | 1 (4.0) | 0 (0) | 0 (0) | 1 (2.1) | ||
| Postlung transplantation | 5 (9.1) | 2 (8.0) | 4 (13.3) | 1 (12.5) | 4 (8.5) | ||
| Asthma or chronic obstructive pulmonary disease exacerbation | 4 (7.3) | 1 (4.0) | 2 (6.7) | 1 (12.5) | 3 (6.4) | ||
| Initial ECMO settings, median (interquartile range) | |||||||
| Blood flow rate (L/m) | 4.5 (4.0–5.1) | 4.8 (3.9–5.2) | 4.5 (4.0–4.9) | 0.43 | 4.3 (3.8–4.8) | 4.5 (4.0–5.2) | 0.29 |
| Sweep gas flow rate (L/m) | 5.0 (3.0–7.0) | 5.0 (3.5–6.0) | 5.0 (2.5–7.0) | 0.64 | 3.8 (2.5–5.5) | 5.0 (3.0–8.0) | 0.25 |
| Fraction of delivered O2 (%) | 100.0 (100.0–100.0) | 100.0 (100.0–100.0) | 100.0 (100.0–100.0) | 0.35 | 100.0 (100.0–100.0) | 100.0 (100.0–100.0) | 0.30 |
| Initial configuration, n (%) | 0.90 | 1.00 | |||||
| Single-site internal jugular | 13 (23.6) | 5 (20.0) | 8 (26.7) | 2 (25.0) | 11 (23.4) | ||
| Dual-site femoral to internal jugular | 39 (70.9) | 19 (76) | 20 (66.7) | 6 (75.0) | 33 (70.2) | ||
| Dual-site femoral to femoral | 3 (5.5) | 1 (4.0) | 2 (6.7) | 0 (0.0) | 3 (6.4) | ||
| Anticoagulation monitoring goals, n (%) | 0.16 | 0.45 | |||||
| Partial thromboplastin time 40–60 s | 32 (58.2) | 12 (48.0) | 20 (66.7) | 6 (75.0) | 26 (55.3) | ||
| Antifactor Xa 0.2–0.4 U/mL | 23 (41.8) | 13 (52.0) | 10 (33.3) | 2 (25.0) | 21 (44.7) | ||
| Laboratory values 24 hr prior to ECMO, median (interquartile range) | |||||||
| Platelets (uL) | 195.0 (129.0–262.0) | 168.5 (108.5–249.0) | 206.0 (154.0–268.0) | 0.23 | 208 (105–286) | 192 (129–262) | 0.97 |
| Hemoglobin (g/dL) | 11.5 (9.7–13.0) | 11.1 (9.3–13.0) | 11.9 (10.9–13.6) | 0.27 | 11.4 (8.1–12.8) | 11.6 (9.7–13.4) | 0.66 |
| Hematocrit (%) | 36 (30.0–39.2) | 34.2 (27.5–39.1) | 37.0 (34.0–40.0) | 0.36 | 34.9 (24.0–39.0) | 36.0 (30.0–40) | 0.60 |
| International normalized ratio | 1.2 (1.1–1.4) | 1.3 (1.2–1.5) | 1.2 (1.0–1.3) | 0.10 | 1.3 (1.2–1.6) | 1.2 (1.1–1.4) | 0.43 |
| Partial thromboplastin time (s) | 37.0 (34.5–62.8) | 36.9 (35.0–63.4) | 38.4 (31.7–48.6) | 0.64 | 35.0 (34.5–35.6) | 38.3 (34.9–63.1) | 0.37 |
| Prothrombin time (s) | 15.4 (13.8–17.2) | 16.1 (14.8–18.0) | 14.8 (13.5–16.3) | 0.10 | 15.1 (14.7–18.5) | 15.4 (13.8–17.2) | 0.69 |
| RBCs transfused per ECMO day (mL) | 62.3 (0.0–140.0) | 140.0 (58.3–185.8) | 43.8 (0.0–87.5) | 0.002 | 108.5 (6.0–336.5) | 62.3 (0.0–139.3) | 0.40 |
| Outcomes | |||||||
| ECMO duration (d), median (interquartile range) | 7.0 (5.0–15.0) | 11.0 (6.0–26.0) | 6.0 (5.0–9.0) | 0.007 | 8.5 (4.0–22.0) | 7.0 (5.0–14.0) | 0.90 |
| Length of hospital stay (d), median (interquartile range) | 21.0 (12.0–36.0) | 22.0 (11.0–36.0) | 20.0 (13.0–28.0) | 0.59 | 21.5 (13.0–33.5) | 21.0 (12.0–36.0) | 0.98 |
| In-hospital survival, n (%) | 37 (67.3) | 11 (44.0) | 26 (86.7) | 0.02 | 5 (62.5) | 32 (68.1) | 0.73a |
ECMO = extracorporeal membrane oxygenation.
ap value calculated using log-rank tests.