Abstract
The hemodynamic effects produced by continuous positive airway pressure (CPAP) and continuous negative extrathoracic pressure (CNEP) of 4 and 8 cm H2O were compared in 8 normal, spontaneously breathing piglets. Arterial blood gases and hemodynamic measurements were obtained before and during CPAP and CNEP of 4 and 8 cm H2O. CPAP 8 cm H2O and CNEP 8 cm H2O produced significant increases (p < 0.01) in PaO2 from baselines 76 ± 3 to 85 ± 3 and 77 ± 4 to 85 ± 3 mmHg,respectively. No significant changes occurred in PaCo2 or cardiac index, except during CPAP 8 cm H2O [38 ± 1 to 44 ± 2 mmHg (p < 0.05) and 376 ± 30 to 330 ± 30 ml/kg/min (p < 0.05), respectively]. During CPAP of 4 cm H2O, significant increases occurred in mean right atrial pressure (P̄ra) (2.1 ± 0.3 to 3.3 ± 0.4 mmHg; p < 0.01), left ventricular end-diastolic pressure (LVEDP) (2.8 ± 0.4 to 3.7 ± 0.3 mmHg; p < 0.01), and mean pulmonary artery pressure (P̄pa) (12.9 ± 0.8 to 15.1 ± 0.8 mmHg; p < 0.01). CPAP of 8 cm H2O produced marked increases in P̄ra (2.1 ± 0.2 to 4.9 ± 0.7 mmHg: p < 0.01), LVEDP (2.7 ± 0.5 to 4.5 ± 0.4 mmHg; p < 0.01) and P̄pa (12.8 ± 0.8 to 17.7 ± 0.6 mmHg, p < 0.01). In contrast, CNEP of 8 cm H2O produced decreases in P̄ra (2.1 ± 0.2 to 1.3 ± 0.3 mmHgHg; p < 0.01), LVEDP (2.6 ± 0.5 to 1.7 ± 0.4mmHg; p < 0.01), and P̄pa (12.9 ± 1.0 to 11.4 ± 1.0 mmHg; p < 0.01). CNEP in contrast to CPAP produced an improvement in oxygenation while decreasing vascular pressures and maintaining cardiac output near basal levels. These data support clinical experience which suggests a beneficial effect of CNEP in the treatment of patients with increased pulmonary vascular resistance and pulmonary hypertension.
Original language | English (US) |
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Pages (from-to) | 69-75 |
Number of pages | 7 |
Journal | Neonatology |
Volume | 62 |
Issue number | 2-3 |
DOIs | |
State | Published - 1992 |
Keywords
- Assisted ventilation
- Continuous negative extrathoracic pressure
- Continuous positive airway pressure
- Hemodynamic
- Neonatal
ASJC Scopus subject areas
- Developmental Biology
- Pediatrics, Perinatology, and Child Health