Hemodynamic directed CPR improves short-term survival from asphyxia-associated cardiac arrest

Abstract

Aim: Adequate coronary perfusion pressure (CPP) during cardiopulmonary resuscitation (CPR) is essential for establishing return of spontaneous circulation. The objective of this study was to compare short-term survival using a hemodynamic directed resuscitation strategy versus an absolute depth-guided approach in a porcine model of asphyxia-associated cardiac arrest. We hypothesized that a hemodynamic directed approach would improve short-term survival compared to depth-guided care.

Methods: After 7 min of asphyxia, followed by induction of ventricular fibrillation, 19 female 3-month old swine (31±0.4 kg) were randomized to receive one of three resuscitation strategies: (1) hemodynamic directed care (CPP-20): chest compressions (CCs) with depth titrated to a target systolic blood pressure of 100 mmHg and titration of vasopressors to maintain CPP>20 mmHg; (2) depth 33 mm (D33): target CC depth of 33 mm with standard American Heart Association (AHA) epinephrine dosing; or (3) depth 51 mm (D51): target CC depth of 51 mm with standard AHA epinephrine dosing. All animals received manual CPR guided by audiovisual feedback for 10 min before first shock.

Results: 45-Min survival was higher in the CPP-20 group (6/6) compared to D33 (1/7) or D51 (1/6) groups; p=0.002. Coronary perfusion pressures were higher in the CPP-20 group compared to D33 (p=0.011) and D51 (p=0.04), and in survivors compared to non-survivors (p<0.01). Total number of vasopressor doses administered and defibrillation attempts were not different.

Conclusions: Hemodynamic directed care targeting CPPs>20 mmHg improves short-term survival in an intensive care unit porcine model of asphyxia-associated cardiac arrest.

Figure 1

Protocol design. During protocol resuscitation period, animals were randomized to receive one of three resuscitation strategies. SBP indicates systolic blood pressure. D33 and D51 refer to depth-directed CPR at 33mm and 51 mm, respectively. CPP-20 refers to CPR directed to attain coronary perfusion pressure >20 mmHg.

Figure 2

Mean coronary perfusion pressure during each minute of CPR across treatment groups (left) and between survivors and non-survivors (right). Error bars represent SEM. D33 and D51 refer to depth-directed CPR at 33mm and 51 mm, respectively. CPP-20 refers to CPR directed to attain coronary perfusion pressure >20 mmHg.