Department of Emergency Medicine

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Browsing Department of Emergency Medicine by Author "Abella, Benjamin S."

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    Association Between Early Hyperoxia Exposure After Resuscitation From Cardiac Arrest and Neurological Disability: Prospective Multicenter Protocol-Directed Cohort Study
    (American Heart Association, 2018-05-15) Roberts, Brian W.; Kilgannon, J. Hope; Hunter, Benton R.; Puskarich, Michael A.; Pierce, Lisa; Donnino, Michael; Leary, Marion; Kline, Jeffrey A.; Jones, Alan E.; Shapiro, Nathan I.; Abella, Benjamin S.; Trzeciak, Stephen; Emergency Medicine, School of Medicine
    BACKGROUND: Studies examining the association between hyperoxia exposure after resuscitation from cardiac arrest and clinical outcomes have reported conflicting results. Our objective was to test the hypothesis that early postresuscitation hyperoxia is associated with poor neurological outcome. METHODS: This was a multicenter prospective cohort study. We included adult patients with cardiac arrest who were mechanically ventilated and received targeted temperature management after return of spontaneous circulation. We excluded patients with cardiac arrest caused by trauma or sepsis. Per protocol, partial pressure of arterial oxygen (Pao2) was measured at 1 and 6 hours after return of spontaneous circulation. Hyperoxia was defined as a Pao2 >300 mm Hg during the initial 6 hours after return of spontaneous circulation. The primary outcome was poor neurological function at hospital discharge, defined as a modified Rankin Scale score >3. Multivariable generalized linear regression with a log link was used to test the association between Pao2 and poor neurological outcome. To assess whether there was an association between other supranormal Pao2 levels and poor neurological outcome, we used other Pao2 cut points to define hyperoxia (ie, 100, 150, 200, 250, 350, 400 mm Hg). RESULTS: Of the 280 patients included, 105 (38%) had exposure to hyperoxia. Poor neurological function at hospital discharge occurred in 70% of patients in the entire cohort and in 77% versus 65% among patients with versus without exposure to hyperoxia respectively (absolute risk difference, 12%; 95% confidence interval, 1-23). Hyperoxia was independently associated with poor neurological function (relative risk, 1.23; 95% confidence interval, 1.11-1.35). On multivariable analysis, a 1-hour-longer duration of hyperoxia exposure was associated with a 3% increase in risk of poor neurological outcome (relative risk, 1.03; 95% confidence interval, 1.02-1.05). We found that the association with poor neurological outcome began at ≥300 mm Hg. CONCLUSIONS: Early hyperoxia exposure after resuscitation from cardiac arrest was independently associated with poor neurological function at hospital discharge.
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    Association Between Elevated Mean Arterial Blood Pressure and Neurologic Outcome After Resuscitation From Cardiac Arrest: Results From a Multicenter Prospective Cohort Study
    (Wolters Kluwer, 2019-01) Roberts, Brian W.; Kilgannon, J. Hope; Hunter, Benton R.; Puskarich, Michael A.; Shea, Lisa; Donnino, Michael; Jones, Christopher; Fuller, Brian M.; Kline, Jeffrey A.; Jones, Alan E.; Shapiro, Nathan I.; Abella, Benjamin S.; Trzeciak, Stephen; Department of Emergency Medicine
    Objective: Laboratory studies suggest elevated blood pressure after resuscitation from cardiac arrest may be protective; however, clinical data are limited. We sought to test the hypothesis that elevated post-resuscitation mean arterial blood pressure (MAP) is associated with neurological outcome. Design: Pre-planned analysis of a prospective cohort study. Setting: Six academic hospitals in the United States. Patients: Adult, non-traumatic cardiac arrest patients treated with targeted temperature management after return of spontaneous circulation (ROSC). Interventions: MAP was measured non-invasively after ROSC and every hour during the initial six hours after ROSC. Measures and Main Results: We calculated the mean MAP and a priori dichotomized subjects into two groups: mean MAP 70–90 and > 90 mmHg. The primary outcome was good neurological function, defined as a modified Rankin Scale (mRS) ≤ 3. The mRS was prospectively determined at hospital discharge. Of the 269 patients included, 159 (59%) had a mean MAP > 90 mmHg. Good neurological function at hospital discharge occurred in 30% of patients in the entire cohort, and was significantly higher in patients with a mean MAP > 90 mmHg (42%) as compared to MAP 70–90 mmHg (15%) [absolute risk difference 27% (95% CI 17%−37%)]. In a multivariable Poisson regression model adjusting for potential confounders, mean MAP > 90 mmHg was associated with good neurological function, adjusted relative risk 2.46 (95% CI 2.09–2.88). Over ascending ranges of mean MAP, there was a dose-response increase in probability of good neurological outcome, with mean MAP > 110 mmHg having the strongest association, adjusted relative risk 2.97 (95% CI 1.86 – 4.76). Conclusions: Elevated blood pressure during the initial six hours after resuscitation from cardiac arrest was independently associated with good neurological function at hospital discharge. Further investigation is warranted to determine if targeting an elevated MAP would improve neurologic outcome after cardiac arrest.
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    Partial pressure of arterial carbon dioxide after resuscitation from cardiac arrest and neurological outcome: A prospective multi-center protocol-directed cohort study
    (Elsevier, 2018) Hope Kilgannon, J.; Hunter, Benton R.; Puskarich, Michael A.; Shea, Lisa; Fuller, Brian M.; Jones, Christopher; Donnino, Michael; Kline, Jeffrey A.; Jones, Alan E.; Shapiro, Nathan I.; Abella, Benjamin S.; Trzeciak, Stephen; Roberts, Brian W.; Emergency Medicine, School of Medicine
    Aims Partial pressure of arterial carbon dioxide (PaCO2) is a regulator of cerebral blood flow after brain injury. We sought to test the association between PaCO2 after resuscitation from cardiac arrest and neurological outcome. Methods A prospective protocol-directed cohort study across six hospitals. Inclusion criteria: age ≥ 18, non-traumatic cardiac arrest, mechanically ventilated after return of spontaneous circulation (ROSC), and receipt of targeted temperature management. Per protocol, PaCO2 was measured by arterial blood gas analyses at one and six hours after ROSC. We determined the mean PaCO2 over this initial six hours after ROSC. The primary outcome was good neurological function at hospital discharge, defined a priori as a modified Rankin Scale ≤ 3. Multivariable Poisson regression analysis was used to test the association between PaCO2 and neurological outcome. Results Of the 280 patients included, the median (interquartile range) PaCO2 was 44 (37-52) mmHg and 30% had good neurological function. We found mean PaCO2 had a quadratic (inverted “U” shaped) association with good neurological outcome, with a mean PaCO2 of 68 mmHg having the highest predictive probability of good neurological outcome, and worse neurological outcome at higher and lower PaCO2. Presence of metabolic acidosis attenuated the association between PaCO2 and good neurological outcome, with a PaCO2 of 51 mmHg having the highest predictive probability of good neurological outcome among patients with metabolic acidosis. Conclusion PaCO2 has a “U” shaped association with neurological outcome, with mild to moderate hypercapnia having the highest probability of good neurological outcome.