Objective To determine the distending pressure needed to achieve sufficient tidal volume (V_T) delivery during continuous chest compressions (CC) superimposed by sustained inflation (SI) (CC+SI).

Design Randomised animal/manikin trial.

Setting University laboratory.

Subjects Cadaver piglets/manikin.

Interventions SI distending pressures of 5, 10, 15, 20, 25 and 30 cm H₂O were delivered in random order during CC+SI for 2 min each.

Main outcome measures V_T, gas flow and airway pressure. Spearman's r for distending pressure and V_T.

Results Distending pressure and V_T correlated in cadaver piglets (r=0.83, p<0.001), manikin (r=0.98, p<0.001) and combined data (r=0.49, p<0.001). V_T was delivered during chest recoil during CC in both models. In cadaver piglets, a distending pressure ∼25 cm H₂O was needed to achieve an adequate V_T.

Conclusions Chest recoil generates V_T depending on an adequate distending pressure. This has previously been demonstrated in adult animals. A pressure of ∼25 cm H₂O is needed to achieve an adequate V_T delivery.