Abstract 19814: A Randomized, Crossover Pilot Trial of Neuromonitoring-Guided Goal-Direct Post-Arrest Care After Opioid Overdose
Introduction: Outcomes after resuscitation from cardiac arrest (CA) remain poor. Preventable secondary injury from ongoing brain tissue hypoxia (BTH) may worsen injury burden. Unfortunately, markers to allow individualized, real-time care optimization are lacking.
Methods: We performed a randomized crossover trial in a swine model of opioid-induced CA to 1) determine the prevalence of BTH with standard care (StdC), and 2) test whether BTH can be prevented with neuromonitor-guided goal-directed care (NGDC). Female swine (25-30kg) were anesthetized with propofol and fentanyl. We placed femoral arterial and venous sheaths, a continuous cardiac output pulmonary artery catheter (Edwards LifeScience) and a right frontal intracranial access bolt (Hemedex) with probes for brain tissue oxygen (PbtO2), pressure (Raumedic), microdialysis (mDialysis70), cerebral blood flow (CBF) (Hemedex), and an electroencephalographic depth electrode (AdTech). We induced apnea with 30mcg/kg fentanyl, extubated the animal and began standard ACLS 9min after apnea. After 1h stabilization, animals with return of spontaneous circulation (ROSC) were randomized to three alternating 6h care blocks: StdC (mean arterial pressure>65mmHg, oxygen saturation 94-98%, cardiac output>75% baseline) or NGDC (PbtO2>20mmHg, CBF>20mL/100g/min). Animals were euthanized at 18h post-ROSC. Our primary outcome was the effect of care block on PbtO2, which we analyzed at 1min resolution using generalized estimating equations with robust standard errors.
Results: Overall, 8 of 17 animals achieved ROSC after 13±3min. PbtO2 was higher during NGDC than StdC (P<0.001) and did not differ during NGDC from pre-arrest. PbtO2 was <20mmHg more during StdC than NGDC (40% of minutes vs 1%, P<0.001). CBF was lower during NGDC than StdC (P<0.001), and lower in both arms than pre-arrest (both P<0.001).
Conclusion: Brain tissue hypoxia was common in this model of swine cardiac arrest and prevented by neuromonitor-guided goal-directed care. Lower CBF during NGDC implies preserved hypoxic cerebral vasodilation and diffusion-limited oxygen delivery. Future work will incorporate electroencephalographic and metabolic injury markers.
Author Disclosures: J. Elmer: Research Grant; Modest; 5K12HL109068. K.L. Flickinger: None. M.W. Anderson: None. A. Koller: None. M. Sundermann: None. C. Dezfulian: Research Grant; Modest; K08NS069817. D.O. Okonkwo: None. L.A. Shutter: None. D. Salcido: Research Grant; Modest; 5K12HL109068. C.W. Callaway: None. J.J. Menegazzi: None.
- © 2016 by American Heart Association, Inc.