Table 1 Cardiovascular response to an increase in positive end expiratory pressure (PEEP) in all 50 infants*.
| Baseline PEEP 5 cmH2O | Intervention PEEP 8 cmH2O | Return to PEEP 5 cmH2O | p Value | |
|---|---|---|---|---|
| Right ventricular output (ml/kg/min) | 234 (103) | 218 (95) | 224 (87) | 0.014 |
| SVC (ml/kg/min) | 92 (36) | 87 (36) | 86 (34) | 0.207 |
| SVC diameter (mm) | 3.7 (1.0) | 3.6 (1.1) | 3.6 (1.0) | 0.040 |
| SVC velocity time integral (m/s) | 0.093 (0.032) | 0.097 (0.035) | 0.090 (0.029) | 0.172 |
| Left pulmonary artery velocity (m/s) | 0.33 (0.11) | 0.32 (0.13) | 0.32 (0.12) | 0.669 |
| Duct diameter (mm) | 2.2 (1.6–3.0) | 2.2 (1.9–28) | 2.1 (1.8–3.1) | 0.628 |
| Ductal shunt (%RL) | 14 (0–25) | 12 (0–27) | 15 (0–28) | 0.760 |
| Middle cerebral artery mean (m/s) | 0.13 (0.09–0.17) | 0.14 (0.10–0.18) | 0.12 (0.09–0.16) | 0.190 |
| Heart rate (beats/min) | 143 (17) | 141 (20) | 143 (19) | 0.198 |
| Systolic blood pressure (mm Hg) | 47 (9) | 48 (9) | 47 (9) | 0.265 |
| Diastolic blood pressure (mm Hg) | 30 (7) | 30 (6) | 30 (6) | 0.602 |
%RL, percentage of cardiac cycle with right to left shunt; SVC, superior vena cava flow; Vti, velocity time integral.
*Values expressed as mean (SD) or median (IQR) where appropriate.