Coronary versus carotid blood flow and coronary perfusion pressure in a pig model of prolonged cardiac arrest treated by different modes of venoarterial ECMO and intraaortic balloon counterpulsation

Abstract

IntroductionExtracorporeal membrane oxygenation (ECMO) is increasingly used in cardiac arrest (CA). Adequacy of carotid and coronary blood flows (CaBF, CoBF) and coronary perfusion pressure (CoPP) in ECMO treated CA is not well established. This study compares femoro-femoral (FF) to femoro-subclavian (FS) ECMO and intraaortic balloon counterpulsation (IABP) contribution based on CaBF, CoBF, CoPP, myocardial and brain oxygenation in experimental CA managed by ECMO.MethodsIn 11 female pigs (50.3 ± 3.4 kg), CA was randomly treated by FF versus FS ECMO ± IABP. Animals under general anesthesia had undergone 15 minutes of ventricular fibrillation (VF) with ECMO flow of 5 to 10 mL/kg/min simulating low-flow CA followed by continued VF with ECMO flow of 100 mL/kg/min. CaBF and CoBF were measured by a Doppler flow wire, cerebral and peripheral oxygenation by near infrared spectroscopy. CoPP, myocardial oxygen metabolism and resuscitability were determined.ResultsCaBF reached values > 80% of baseline in all regimens. CoBF > 80% was reached only by the FF ECMO, 90.0% (66.1, 98.6). Addition of IABP to FF ECMO decreased CoBF to 60.7% (55.1, 86.2) of baseline, P = 0.004. FS ECMO produced 70.0% (49.1, 113.2) of baseline CoBF, significantly lower than FF, P = 0.039. Addition of IABP to FS did not change the CoBF; however, it provided significantly higher flow, 76.7% (71.9, 111.2) of baseline, compared to FF + IABP, P = 0.026. Both brain and peripheral regional oxygen saturations decreased after induction of CA to 23% (15.0, 32.3) and 34% (23.5, 34.0), respectively, and normalized after ECMO institution. For brain saturations, all regimens reached values exceeding 80% of baseline, none of the comparisons between respective treatment approaches differed significantly. After a decline to 15 mmHg (9.5, 20.8) during CA, CoPP gradually rose with time to 68 mmHg (43.3, 84.0), P = 0 .003, with best recovery on FF ECMO. Resuscitability of the animals was high, both 5 and 60 minutes return of spontaneous circulation occured in eight animals (73%).ConclusionsIn a pig model of CA, both FF and FS ECMO assure adequate brain perfusion and oxygenation. FF ECMO offers better CoBF than FS ECMO. Addition of IABP to FF ECMO worsens CoBF. FF ECMO, more than FS ECMO, increases CoPP over time.

Median Frequencies of Prolonged Ventricular Fibrillation treated by V-A ECMO Correspond to a Return of Spontaneous Circulation Rate

“…In a rat study, Choi et al (37) proved that CPR maintains myocardial ATP for only 2 min with subsequent decline despite ongoing resuscitation. We have shown that ECMO-based resuscitation maintains myocardial oxygen extraction, lactate and MF stable for more than two hours (26). In another study, Shibayama et al showed in canine ex vivo model of CA, that early asystolic hearts, i.e., hearts developing asystoly following unresuscitated VF, had more ADP, less phosphocreatine, and higher levels of lactate in contrary to late asystolic hearts (38).…”

“…This approach is aimed to sustain vital organ perfusion during CA to provide time span for diagnosis and therapy (23). Recently, the impact of different veno-arterial (V-A) ECMO settings on brain and coronary perfusion was described by our team in a pig model of prolonged VF (26). However, no research focused on analysis of intracardially recorded VF wavelet pattern during simulated prolonged CA treated by ECMO is available.…”

“…ECMO assures adequate coronary perfusion and metabolic state in prolonged VF (26), also reflected by the MF of the VF wavelet, and thus offers a reasonable chance for successful countershock and ROSC achievement in case of refractory VF. In clinical practice, we frequently encounter patients with prolonged CA (often refractory VF) caused by a potentially treatable condition.…”

“…The protocol used in this study has been described in detail previously (26) and is outlined in Figure 1. Briefly, 12 female pigs (Sus scrofa domestica), crossbreed (Landrace x Large white), body weights 50.3 ± 3.4 kg were used.…”

“…The data were compared to coronary perfusion pressure (CoPP), level of lactate in coronary sinus, cardiac oxygen extraction and occurrence of ROSC. Cardiac O 2 extraction was estimated as arterio-venous difference in blood O 2 content per 1L of blood as described previously (26). ROSC was defined as a supraventricular rhythm with hemodynamically effective pulsations regardless of ECMO flow with mean invasive arterial pressure in descendent aorta of 60 mmHg or more evaluated at 5 minutes following first defibrillation.…”