Table 1.
Characteristics of Study Cohort
| Variables | Total | Palpation | Ultrasound | p-value * |
|---|---|---|---|---|
| Observed procedures, n (% total) | 208 (100) | 126 (60.6) | 82 (39.4) | n/a |
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| Patient Variables | ||||
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| Age, mean years (± SD) | 5.8 (5.3) | 5.7 (5.5) | 5.9 (4.9) | 0.782 |
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| Male, n (%) | 113 (54.3) | 73 (57.9) | 40 (48.8) | 0.203 |
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| Ethnicity, n (%) | ||||
| African American | 35 (16.8) | 22 (17.5) | 13 (15.9) | 0.764 |
| Caucasian | 100 (48.1) | 61 (48.4) | 39 (47.5) | 0.904 |
| Hispanic | 51 (24.5) | 30 (23.8) | 21 (25.6) | 0.769 |
| Other | 22 (10.6) | 13 (10.3) | 9 (11.0) | 0.881 |
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| Anthropometrics ♯ | ||||
| Weight-for-age, %ile, mean (± SD) | 42.1 (26.3) | 39.9 (27.1) | 45.6 (24.9) | 0.125 |
| BMI, %ile, mean (± SD) | 47.8 (26.5) | 43.9 (25.7) | 52.8 (27.0) | 0.053 |
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| Blood pressure § | ||||
| Systolic pressure, %ile, mean (± SD) | 23.2 (22.5) | 22.5 (22.0) | 24.4 (23.3) | 0.541 |
| Mean pressure, %ile, mean (± SD) | 14.1 (10.9) | 13.6 (10.6) | 14.8 (11.4) | 0.439 |
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| Fluid overload percent ∫ | 6.7 (4.4) | 6.5 (4.5) | 7.0 (4.3) | 0.786 |
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| PIM3 probability, mean (± SD) † | 6.8 (7.9) | 6.7 (7.9) | 6.9 (7.7) | 0.810 |
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| Mechanical ventilation, n (%) ‡ | 190 (91.3) | 113 (89.7) | 77 (93.9) | 0.326 |
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| Vasopressor, n (%) Σ | 141 (67.8) | 83 (65.9) | 58 (70.7) | 0.544 |
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| Sedation infusion, n (%) | 186 (89.4) | 111 (88.1) | 75 (91.5) | 0.497 |
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| Wrist flexion contractures, n (%) | 54 (26.0) | 32 (25.4) | 22 (26.8) | 0.872 |
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| Trainee Variables | ||||
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| Trainees, n (%) | 45 (100) | 37 (82.2) | 22 (48.9) | n/a |
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| Post graduate years, mean (± SD) ° | 5.5 (1.1) | 5.6 (1.1) | 5.4 (1.2) | 0.332 |
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| Months in fellowship, mean (± SD) | 17.4 (9.1) | 17.3 (9.5) | 17.7 (8.5) | 0.792 |
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| Prior procedures, mean (± SD) ♮ | 30.5 (16.9) | 29.45 (17.5) | 32.2 (15.9) | 0.274 |
*
Student’s t-test or Pearson’s chi squared test for continuous or categorical variables, respectively
♯
World Health Organization child growth standards (WHO, 2006)
§
Non-invasive BP at procedure start; %tiles derived from NHLBI, 2005 and Voors et al,1977
∫
(Fluid intake - fluid output (mL) from PICU admission)/admit weight (kg) * 100
†
Pediatric Index of Mortality 3 (Straney et al, 2013)
‡
Invasive and non-invasive modes of ventilation
Σ
Dopamine infusion ≥ 10 mcg/kg/min, and/or epinephrine or norepinephrine infusion ≥ 0.05 mcg/kg/min
°
Years since medical school graduation
♮
Self-reported number of arterial lines logged prior to date of observed procedure