Tidal volume delivery during continuous chest compressions and sustained inflation

Area of Science:

• Cardiopulmonary resuscitation
• Mechanical ventilation
• Respiratory physiology

Background:

• Effective ventilation is critical during cardiopulmonary resuscitation (CPR).
• Sustained inflation (SI) combined with chest compressions (CC) is a ventilation strategy used in CPR.
• The optimal distending pressure for SI during CC is not well-established.

Purpose of the Study:

• To determine the necessary distending pressure for adequate tidal volume (VT) delivery during continuous chest compressions with superimposed sustained inflation (CC+SI).

Main Methods:

• A randomized animal/manikin trial was conducted in a university laboratory setting.
• Cadaver piglets and a manikin were used as subjects.
• SI distending pressures ranging from 5 to 30 cmH2O were applied during CC+SI, with tidal volume, gas flow, and airway pressure measured.

Main Results:

• A strong correlation was observed between distending pressure and tidal volume in both cadaver piglets (r=0.83) and the manikin (r=0.98).
• Tidal volume was delivered during chest recoil in both models.
• Approximately 25 cmH2O distending pressure was required to achieve adequate tidal volume in cadaver piglets.

Conclusions:

• Chest recoil is a key mechanism for generating tidal volume during CC+SI.
• Adequate distending pressure is essential for effective tidal volume delivery.
• A distending pressure of approximately 25 cmH2O is needed to achieve adequate tidal volume delivery during CC+SI.