Table 1.
Baseline Characteristics of the Study Patients, According to Group.
| Variable | Intervention (N=1225) | Control (N=1224) | P Valuea |
|---|---|---|---|
| Age at PICU admission | |||
| Median (IQR) – years | 1.4 (0.3–7.0) | 2.6 (0.6–9.2) | 0.002 |
| 2 weeks to 1.99 years – no. (%) | 715 (58) | 550 (45) | <0.001 |
| 2.00 to 5.99 years | 176 (14) | 243 (20) | |
| 6.00 to 17.99 years | 334 (27) | 431 (35) | |
| Female sex – no. (%) | 558 (46) | 543 (44) | 0.53 |
| Non-Hispanic white – no./total no. (%) | 631/1215 (52) | 602/1210 (50) | 0.81 |
| Baseline PCPC = 1 – no. (%)b | 942 (77) | 923 (75) | 0.41 |
| Baseline POPC = 1 – no. (%)b | 885 (72) | 862 (70) | 0.51 |
| Able to verbally communicate pain at baseline – no./total no. (%)c | 398/616 (65) | 565/768 (74) | 0.21 |
| PRISM III-12 score – median (IQR) | 6 (3–11) | 8 (5–13.5) | 0.005 |
| Percent risk of mortality based on PRISM III-12 score – median (IQR) | 2.4 (1.0–9.5) | 4.8 (1.7–15.0) | 0.01 |
| 2 weeks to 1.99 years | 1.7 (0.7–4.9) | 3.8 (1.3–9.5) | 0.003 |
| 2.00 to 5.99 years | 3.3 (1.2–17.2) | 4.8 (1.7–17.0) | 0.56 |
| 6.00 to 17.99 years | 7.7 (1.8–19.6) | 7.7 (2.2–26.2) | 0.54 |
| Primary diagnosis – no. (%) | <0.001 | ||
| Pneumonia | 394 (32) | 433 (35) | |
| Bronchiolitis | 428 (35) | 228 (19) | |
| Acute respiratory failure related to sepsis | 145 (12) | 212 (17) | |
| Asthma or reactive airway disease | 87 (7) | 120 (10) | |
| Aspiration pneumonia | 70 (6) | 79 (6) | |
| Otherd | 101 (8) | 152 (12) | |
| PARDS based on Day 1 OI or OSI – no. (%)e | 0.83 | ||
| At risk (OI <4.0 or OSI <5.0) | 472 (39) | 460 (38) | |
| Mild (OI 4.0–7.9 or OSI 5.0–7.4) | 308 (25) | 351 (29) | |
| Moderate (OI 8.0–16.0 or OSI 7.5–12.3) | 279 (23) | 254 (21) | |
| Severe (OI >16.0 or OSI >12.3) | 166 (14) | 159 (13) | |
| Neuromuscular blockade for the entire duration of Days 0 to 2 – no. (%) | 82 (7) | 92 (8) | 0.64 |
| Any past medical history – no. (%) | |||
| Prematurity (<36 weeks post-menstrual age) | 194 (16) | 175 (14) | 0.37 |
| Asthma (prescribed bronchodilators or steroids) | 146 (12) | 210 (17) | 0.18 |
| Seizure disorder (prescribed anticonvulsants) | 112 (9) | 112 (9) | 0.76 |
| Neurologic/neuromuscular disorder which places patient at risk for aspiration | 105 (9) | 96 (8) | 0.62 |
| Cancer (current or past diagnosis) | 88 (7) | 109 (9) | 0.31 |
| Known chromosomal abnormality | 60 (5) | 48 (4) | 0.24 |
| Chronic tracheostomy – no. (%) | 11 (<1) | 11 (<1) | 0.74 |
| Intubated at outside hospital and transferred to participating PICU – no. (%) | 334 (27) | 306 (25) | 0.23 |
Abbreviations: IQR, interquartile range; OI, oxygenation index; OSI, oxygen saturation index; PARDS, pediatric acute respiratory distress syndrome; 47,48 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, cumulative logit, logistic, and multinomial logistic regression accounting for PICU as a cluster variable using generalized estimating equations for log-transformed continuous, ordinal, binary, and nominal variables, respectively.
PCPC and POPC range from 1 to 6, with higher categories indicating greater impairment.
Able to verbally communicate pain at baseline includes only patients aged 16 months and older.
Other primary diagnoses include pulmonary edema, thoracic trauma, pulmonary hemorrhage, laryngotracheobronchitis, acute respiratory failure post bone marrow transplant, acute chest syndrome/sickle cell disease, pertussis, pneumothorax (non-trauma), acute exacerbation lung disease (cystic fibrosis or bronchopulmonary dysplasia), acute respiratory failure related to multiple blood transfusions, pulmonary hypertension (not primary), and other.
Oxygenation index (OI) was calculated as [(FIO2 × mean airway pressure)/PaO2 × 100]. When an arterial blood gas was not available, SpO2 was used to estimate PaO2 in order to calculate oxygen saturation index (OSI) [(FIO2 × mean airway pressure)/SpO2 × 100]. Lower scores reflect better oxygenation.