Synchronous mechanical ventilation of the neonate with respiratory disease

Abstract

Objectives: To assess the importance of synchronization of mechanical ventilation with spontaneous respiratory efforts in mechanically ventilated neonates. The actions of this synchronization on ventilation, oxygenation, and BP variation were assessed.

Design: Prospective evaluation using within-subject comparison of asynchronous and synchronous states.

Setting: Neonatal ICU in a large, university-affiliated hospital.

Patients: Fourteen neonates requiring mechanical ventilation who were initially asynchronous with the ventilator.

Intervention: The ventilator settings were adjusted using the patients' own inspiratory and expiratory timing to create synchronous interaction with the ventilator.

Measurements and main results: Synchrony was assessed using clinical observation combined with inspection of the air flow waveform and computerized analysis of the air flow signal to assess cycle-to-cycle reproducibility, so-called autocorrelation. Synchronous ventilation significantly improved tidal volume (p < .05), minute volume (p < .001), and all indices of the variability of arterial BP (p < .001). Mean airway pressure did not change significantly. No infant developed an airleak syndrome or intraventricular hemorrhage, which have previously been associated with asynchronous ventilation and an unstable BP, respectively.

Conclusion: Synchronous ventilation can be readily applied to most ventilated neonates. It improves ventilation, and results in a marked reduction in BP variation, which may have implications for reducing the risk of intraventricular hemorrhage.