Blood pressure during resuscitation in man--the effect of pause during rhythm analysis revisited

This study reports invasive arterial pressures before and after the rhythm analysing pauses during CPR and evaluates the possible association of the quality of CPR and the length of the pause with blood pressure around the pause.

Five patients who experienced out-of hospital or in-hospital cardiac arrest were included in the study. Using a monitor/defibrillator with sensing capabilities, the parameters of CPR quality including chest compression depth, rate, force and the duration of interruption were recorded and compared to blood pressure.

Altogether 42 pauses were observed in five patients with a duration of 9±5 s (mean±SD). The values for systolic (SAP), mean (MAP) and diastolic arterial pressures (DAP) were 107±30, 44±12 and 14±12 mmHg before the pause and 119±34, 49±13 and 14±14 mmHg after the pause, respectively. There was a statistically significant increase in both SAP (12.1±28.2 mmHg; p=0.021) and MAP (4.2±8.7 mmHg (p=0.008) and the duration of the pause was identified as an independent factor for that in a linear mixed model. The pause duration up to ten seconds maintained the pressure achieved if the compression depth was immediately according to the guidelines (p=0.046).

Contrary to the previous animal studies, this preliminary study in humans demonstrates that blood pressures achieved before the rhythm analysis pause do not necessarily decrease after the pause but may even increase if the duration of the pause is under ten seconds and the quality of CPR is good both before and after the pause.