Improving post-cardiac arrest cerebral perfusion pressure by elevating the head and thorax

Aim: The optimal head and thorax position after return of spontaneous circulation (ROSC) following cardiac arrest (CA) is unknown. This study examined whether head and thorax elevation post-ROSC is beneficial, in a porcine model.

Methods: Protocol A: 40 kg anesthetized pigs were positioned flat, after 7.75 min of untreated CA the heart and head were elevated 8 and 12 cm, respectively, above the horizontal plane, automated active compression decompression (ACD) plus impedance threshold device (ITD) CPR was started, and 2 min later the heart and head were elevated 10 and 22 cm, respectively, over 2 min to the highest head up position (HUP). After 30 min of CPR pigs were defibrillated and randomized 10 min later to four 5-min epochs of HUP or flat position. Multiple physiological parameters were measured. In Protocol B, after 6 min of untreated VF, pigs received 6 min of conventional CPR flat, and after ROSC were randomized HUP versus Flat as in Protocol A. The primary endpoint was cerebral perfusion pressure (CerPP). Multivariate analysis-of-variance (MANOVA) for repeated measures was used. Data were reported as mean ± SD.

Results: In Protocol A, intracranial pressure (ICP) (mmHg) was significantly lower post-ROSC with HUP (9.1 ± 5.5) versus Flat (18.5 ± 5.1) (p < 0.001). Conversely, CerPP was higher with HUP (62.5 ± 19.9) versus Flat (53.2 ± 19.1) (p = 0.004), respectively. Protocol A and B results comparing HUP versus Flat were similar.

Conclusion: Post-ROSC head and thorax elevation in a porcine model of cardiac arrest resulted in higher CerPP and lower ICP values, regardless of VF duration or CPR method.

Iacuc protocol number: 19-09.