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Negative-pressure ventilation improves cardiac output after right heart surgery
L S Shekerdemian1, D F Shore, C Lincoln
1Department of Pediatrics, Royal Brompton Hospital, London, UK.
Circulation
|November 1, 1996
Summary
Negative-pressure ventilation significantly improved cardiac output in children after complex heart surgery. This method enhanced stroke volume and reduced vascular resistance, offering a potential therapy for low cardiac output states.
Area of Science:
- Pediatric Cardiology
- Cardiovascular Surgery
- Respiratory Physiology
Background:
- Low cardiac output state is a common complication after Fontan-type operations and tetralogy of Fallot repair.
- Effective postoperative management is crucial for these high-risk pediatric patients.
Purpose of the Study:
- To investigate the impact of negative-pressure ventilation on cardiac output in children post-right heart surgery.
- To evaluate changes in stroke volume, vascular resistance, and oxygenation during negative-pressure ventilation.
Main Methods:
- Evaluated 11 children in the early postoperative period after right heart surgery.
- Compared volume-cycled intermittent positive-pressure ventilation with high-frequency oscillatory negative-pressure ventilation (Hayek oscillator).
- Measured cardiac output using the direct Fick method and oxygen consumption via respiratory mass spectrometry.
Main Results:
- Negative-pressure ventilation increased cardiac output by 46% (P = .005) and stroke volume by 48.5% (P = .005).
- Heart rate remained unchanged, while mixed venous saturation increased by 4.6% (P < .02).
- Systemic and pulmonary vascular resistances were significantly reduced during negative-pressure ventilation (P < .05 and P < .03, respectively).
Conclusions:
- Negative-pressure ventilation is an effective method for improving cardiac output in pediatric patients following total cavopulmonary connection and tetralogy of Fallot repair.
- This ventilatory strategy may serve as a valuable therapeutic option for managing low cardiac output states in children post-cardiac surgery.