Table 1.
Patient Characteristics According to Group
| Characteristics | ECMO (n = 61) | No ECMO (n = 1194) | pa |
|---|---|---|---|
| Age at PICU admission, median (IQR), y | 4.2 (0.8–12.0) | 2.6 (0.5–9.3) | 0.04 |
| Female sex, n (%) | 39 (64) | 563 (47) | <0.001 |
| Non-Hispanic white, n/total (%) | 30/57 (53) | 620/1183 (52) | 0.80 |
| Cognitive impairment (baseline PCPC score >1), n (%) | 6 (10) | 301 (25) | 0.002 |
| Functional impairment (baseline POPC score >1), n (%) | 9 (15) | 363 (30) | 0.006 |
| PRISM III-12 score, median (IQR) | 12 (4–21) | 8 (3–14) | 0.09 |
| Percent risk of mortality based on PRISM III-12 score, median (IQR) | 13.1 (1.7–42.6) | 4.6 (1.3–15.0) | 0.02 |
| Primary diagnosis, n (%) | 0.09 | ||
| Pneumonia | 28 (46) | 411 (34) | |
| Bronchiolitis | 8 (13) | 292 (24) | |
| Acute respiratory failure related to sepsis | 14 (23) | 197 (17) | |
| Asthma or reactive airway disease | 6 (10) | 87 (7) | |
| Aspiration pneumonia | 1 (2) | 71 (6) | |
| Otherb | 4 (7) | 136 (11) | |
| Past medical history, n (%) | |||
| Prematurity (<36 wk postmenstrual age) | 8 (13) | 188 (16) | 0.58 |
| Asthma (prescribed bronchodilators or steroids) | 7 (11) | 180 (15) | 0.43 |
| Seizure disorder (prescribed anticonvulsants) | 3 (5) | 108 (9) | 0.22 |
| Cancer (current or previous diagnosis) | 8 (13) | 123 (10) | 0.47 |
| Known chromosomal abnormality | 2 (3) | 60 (5) | 0.48 |
| Intervention group, n (%) | 29 (48) | 582 (49) | 0.92 |
| PARDS based on worst OI or OSI on Days 0 to 1, n (%)c | <0.001 | ||
| Moderate (OI 8.0–15.9 or OSI 7.5–12.2) | 4 (7) | 576 (48) | |
| Severe (OI ≥16.0 or OSI ≥12.3) | 57 (93) | 618 (52) | |
| Organ dysfunctions on Days 0 to 1, median (IQR)d | 3 (2–4) | 2 (1–3) | <0.001 |
| Neuromuscular blockade for the entire duration of Days 0 to 2, n (%) | 15 (25) | 115 (10) | 0.009 |
ECMO = extracorporeal membrane oxygenation, IQR = interquartile range, OI = oxygenation index, OSI = oxygen saturation index, PARDS = pediatric acute respiratory distress syndrome, PCPC = Pediatric Cerebral Performance Category, PICU = pediatric intensive care unit, POPC = Pediatric Overall Performance Category, PRISM III-12 = Pediatric Risk of Mortality III score from first 12 hours in the PICU.
P values for the comparison between groups were calculated using linear, logistic, multinomial logistic, and cumulative logit regression for log-transformed continuous, binary, nominal, and ordinal variables, respectively. All regression analyses except for primary diagnosis accounted for PICU as a cluster variable using generalized estimating equations.
Other primary diagnoses include pulmonary edema, thoracic trauma, pulmonary hemorrhage, laryngotracheobronchitis, acute respiratory failure after bone marrow transplantation, acute chest syndrome/sickle cell disease, pertussis, pneumothorax (nontrauma), acute exacerbation lung disease (cystic fibrosis or bronchopulmonary dysplasia), acute respiratory failure related to multiple blood transfusions, pulmonary hypertension (not primary), and pulmonary embolus.
Oxygenation index was calculated as ([FIO2 × mean airway pressure]/PaO2 × 100). When an arterial blood gas measurement was not available, SpO2 was used to estimate PaO2 in order to calculate OSI ([FIO2 × mean airway pressure]/SpO2 × 100). Lower scores reflect better oxygenation.
Number of organ dysfunctions ranges from 1 to 6. All patients had respiratory dysfunction. Cardiovascular dysfunction based on vasoactive medication use (single or multiple). Neurologic dysfunction based on worst level of consciousness (stupor or coma) or pupillary response (one or both pupils non-reactive). Hematologic dysfunction based on platelet threshold (<80 K/μL). Renal dysfunction based on age-specific creatinine thresholds. Hepatic dysfunction based on age- and gender-specific ALT thresholds or total bilirubin thresholds.