Comatose Out-of-hospital Cardiac Arrest Patients Research Articles

ED prognostication of comatose cardiac arrest patients undergoing therapeutic hypothermia is unreliable

BackgroundTherapeutic hypothermia (TH) improves patient survival with good neurologic outcome after cardiac arrest. The value of early clinician prognostication in the emergency department (ED) has not been studied in this patient population. ObjectiveTo determine if physicians can accurately predict survival and neurologic outcome at hospital discharge of resuscitated, comatose out-of-hospital cardiac arrest (OHCA) patients treated in a post–cardiac arrest clinical pathway that included TH. MethodsThis was a prospective, observational study conducted at a tertiary referral center. Participants were physicians involved in the resuscitation of OHCA patients treated with a clinical pathway that included TH. Immediately after patient resuscitation in the ED, physicians recorded their prediction of patient survival and neurologic outcome on a standardized questionnaire. Neurologic outcome was assessed by the cerebral performance category. ResultsForty-two physicians completed questionnaires on 17 patients enrolled from October 2009 to March 2010. Sensitivity and specificity of physician prediction of patient survival were 0.67 (95% confidence interval [CI], 0.45-0.83) and 0.82 (95% CI, 0.59-0.94), respectively, with an area under the curve of 0.74 (95% CI, 0.61-0.88), a positive likelihood ratio (+LR) of 3.72 (95% CI, 1.30-11.02), and a −LR of 0.40 (95% CI, 0.21-0.77). Sensitivity and specificity of physician prediction of good neurologic outcome were 0.40 (95% CI, 0.20-0.64) and 0.69 (95% CI, 0.50-0.84), respectively, with an area under the curve of 0.55 (95% CI, 0.39-0.70), a +LR of 1.29 (95% CI, 0.56-3.03), and a −LR of 0.87 (95% CI, 0.53-1.41). ConclusionsPhysicians poorly prognosticate both survival and neurologic outcome in comatose OHCA patients undergoing TH. Premature prognostication in the ED is unreliable and should be avoided.

Urban and Suburban Hospital System Implementation of Multipoint Access Targeted Temperature Management in Postcardiac Arrest Patients

Cardiac arrest is a prominent cause of death for adults in the United States. Postcardiac arrest syndrome can have devastating consequences ranging from mild memory impairment to permanent neurologic deficits. Only 9.5% of out-of-hospital cardiac arrest (OHCA) patients survive to discharge. Since 2002, scientific literature has supported the use of targeted temperature management (TTM) for improved outcomes in comatose OHCA patients. There is limited use of TTM protocols for cardiac arrest survivors in clinical practice, as translation of evidence-based guidelines into clinical practice remains a complicated task. The authors' goal was to utilize the Promoting Action on Research Implementation in Health Services (PARiHS) framework prospectively to develop a TTM program for OHCA survivors in two community hospitals. A collaborative team of providers from an urban hospital and a suburban hospital joined forces to bring evidence into practice with the endpoint of initiating TTM in the emergency, cardiac catheterization, and intensive care units. TTM was successfully implemented with multiple points of access within two community hospitals. The investigative program cared for 25 OHCA patients during the first year of inception. The TTM patients who survived to discharge displayed a trend of improved neurologic outcome based on the modified Rankin scale and a slight increase in the survival to discharge rate.

Hemodynamics and vasopressor support in therapeutic hypothermia after cardiac arrest: Prognostic implications

AimInducing therapeutic hypothermia (TH) in Out-of-Hospital Cardiac Arrest (OHCA) can be challenging due to its impact on central hemodynamics and vasopressors are frequently used to maintain adequate organ perfusion. The aim of this study was to assess the association between level of vasopressor support and mortality. MethodsIn a 6-year period, 310 comatose OHCA patients treated with TH were included. Temperature, hemodynamic parameters and level of vasopressors were registered from admission to 24h after rewarming. Level of vasopressor support was assessed by the cardiovascular sub-score of Sequential Organ Failure Assessment (SOFA). The population was stratified by use of dopamine as first line intervention (D-group) or use of dopamine+norepinephrine/epinephrine (DA-group). Primary endpoint was 30-day mortality and secondary endpoint was in-hospital cause of death. ResultsPatients in the DA-group carried a 49% all-cause 30-day mortality rate compared to 23% in the D-group, plog-rank<0.0001, corresponding to an adjusted hazard ratio (HR) of 2.0 (95% CI: 1.3–3.0), p=0.001). The DA-group had an increased 30-day mortality due to neurological injury (HR=1.7 (95% CI: 1.1–2.7), p=0.02). Cause of death was anoxic brain injury in 78%, cardiovascular failure in 18% and multi-organ failure in 4%. The hemodynamic changes of TH reversed at normothermia, although the requirement for vasopressor support (cardiovascular SOFA≥3) persisted in 80% of patients. ConclusionsIn survivors after OHCA treated with TH the induced hemodynamic changes reversed after normothermia, while the need for vasopressor support persisted. Patients requiring addition of norepinephrine/epinephrine on top of dopamine had an increased 30-day all-cause mortality, as well as death from neurological injury.

Awakening after cardiac arrest and post resuscitation hypothermia: Are we pulling the plug too early?

BackgroundTime to awakening after out-of-hospital cardiac arrest (OHCA) and post-resuscitation therapeutic hypothermia (TH) varies widely. We examined the time interval from when comatose OHCA patients were rewarmed to 37°C to when they showed definitive signs of neurological recovery and tried to identify potential predictors of awakening. MethodsWith IRB approval, a retrospective case study was performed in OHCA patients who were comatose upon presentation to a community hospital during 2006–2010. They were treated with TH (target of 33°C) for 24h, rewarmed, and discharged alive. Comatose patients were generally treated medically after TH for at least 48h before any decision to withdraw supportive care was made. Pre-hospital TH was not used. Data are expressed as medians and interquartile range. ResultsThe 89 patients treated with TH in this analysis were divided into three groups based upon the time between rewarming to 37°C and regaining consciousness. The 69 patients that regained consciousness in ≤48h after rewarming were termed “early-awakeners”. Ten patients regained consciousness 48–72h after rewarming and were termed “intermediate-awakeners”. Ten patients remained comatose and apneic >72h after rewarming but eventually regained consciousness; they were termed “late-awakeners”. The ages for the early, intermediate and late awakeners were 56 [49,65], 62 [48,74], and 58 [55,65] years, respectively. Nearly 67% were male. Following rewarming, the time required to regain consciousness for the early, intermediate and late awakeners was 9 [2,18] (range 0–47), 60.5 [56,64.5] (range 49–71), and 126 [104,151]h (range 73–259), respectively. Within 90 days of hospital admission, favorable neurological function based on a Cerebral Performance Category (CPC) score of 1 or 2 was reported in 67/69 early, 10/10 intermediate, and 8/10 late awakeners. ConclusionFollowing OHCA and TH, arbitrary withdrawal of life support <48h after rewarming may prematurely terminate life in many patients with the potential for full neurological recovery. Additional clinical markers that correlate with late awakening are needed to better determine when withdrawal of support is appropriate in OHCA patients who remain comatose >48h after rewarming.

Haemodynamic variables and functional outcome in hypothermic patients following out-of-hospital cardiac arrest

Aim of the studyTo evaluate the association between haemodynamic variables during the first 24h after intensive care unit (ICU) admission and neurological outcome in out-of-hospital cardiac arrest (OHCA) victims undergoing therapeutic hypothermia. MethodsIn a multi-disciplinary ICU, records were reviewed for comatose OHCA patients undergoing therapeutic hypothermia. The hourly variable time integral of haemodynamic variables during the first 24h after admission was calculated. Neurologic outcome was assessed at day 28 and graded as favourable or adverse based on the Cerebral Performance Category of 1–2 and 3–5. Bi- and multivariate regression models adjusted for confounding variables were used to evaluate the association between haemodynamic variables and functional outcome. Results67/134 patients (50%) were classified as having favourable outcome. Patients with adverse outcome had a higher mean heart rate (73 [62–86] vs. 66 [60–78]bpm; p=0.04) and received noradrenaline more frequently (n=17 [25.4%] vs. n=9 [6%]; p=0.02) and at a higher dosage (128 [56–1004] vs. 13 [2–162] μgh−1; p=0.03) than patients with favourable outcome. The mean perfusion pressure (mean arterial blood pressure minus central venous blood pressure) (OR=1.001, 95% CI =1–1.003; p=0.04) and cardiac index time integral (OR=1.055, 95% CI=1.003–1.109; p=0.04) were independently associated with adverse outcome at day 28. ConclusionMean perfusion pressure and cardiac index during the first 24h after ICU admission were weakly associated with neurological outcome in an OHCA population undergoing therapeutic hypothermia. Further studies need to elucidate whether norepinephrine-induced increases in perfusion pressure and cardiac index may contribute to adverse neurologic outcome following OHCA.