Short paperRecovery among post-arrest patients with mild-to-moderate cerebral edema
Introduction
Early cerebral edema seen on computerized tomography (CT) imaging of the brain is an ominous sign after resuscitation from cardiac arrest.1, 2 Beyond marking injury severity, cerebral edema may contribute to preventable secondary brain injury by compromising capillary blood flow, increasing capillary-tissue oxygen gradients, or raising intracranial pressure.3, 4 These effects may decrease cerebral blood flow and oxygen delivery.3, 4 Edema severity can be approximated by the ratio of grey matter attenuation to white matter attenuation (GWR) on CT imaging. Previous studies have shown that severe edema (GWR <1.1) likely reflects irrecoverable brain injury.2, 5 These studies found variable recovery among patients with GWR 1.2–1.3.2, 5
Whether mild to moderate cerebral edema is a modifiable contributor to secondary brain injury is unknown. We analyzed a large cohort of subjects with potentially recoverable early cerebral edema, described their baseline clinical phenotypes, and sought to identify modifiable factors associated with survival without severe neurological impariment. Specifically, we hypothesized that higher sedation dose, temperature management to 33 °C and rising serum osmolality would be associated with improved outcome.
Section snippets
Setting and population
The University of Pittsburgh Human Research Protection Office approved this study. We performed a retrospective observational cohort study including consecutive patients admitted to a single academic medical center in Western Pennsylvania after resuscitation from out-of-hospital cardiac arrest (OHCA) with GWR 1.2–1.3 on initial brain CT. In a secondary analysis, we included patients with GWR 1.2−1.4. We excluded patients that were awake (following verbal commands) or died within 6 h of return
Results
We identified 1500 out-of-hospital cardiac arrest during our study period of which 214 met inclusion and exclusion criteria (Fig. 1). Median age was 57 [interquartile range (IQR) 48−67] years, 82 (38%) were female, and the most common presenting rhythm was ventricular tachycardia or fibrillation (32%) (Table 1). The large majority of CT scans (88%) were obtained within 6 h of collapse. CPC 1–3 was seen in 43 (21%) patients, with the median length of stay for survivors 15 [IQR 9–22] days.
In
Discussion
We did not identify modifiable processes of care associated with recovery among patients with mild-to-moderate cerebral edema. Both cytotoxic and vasogenic components contribute to edema formation in this population.3, 11 Disruption of the blood brain barrier (BBB) from oxidative stress or inflammation, for example, results in extravasation of large osmotically active molecules and fluid typically excluded from the extracellular space, although some data suggest that ionic shifts and active
Conflicts of interests
All authors declare no conflicts of interests
CRediT authorship contribution statement
Zachary L. Fuller: Conceptualization, Methodology, Formal analysis, Writing - original draft. John W. Faro: Data curation, Writing - review & editing. Clifton W. Callaway: Methodology, Supervision, Writing - review & editing. Patrick J. Coppler: Data curation, Writing - review & editing. Jonathan Elmer: Conceptualization, Methodology, Supervision, Writing - original draft.
Acknowledgement
Dr. Elmer’s research time is supported by the NIH through grant 5K23NS097629.
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Therapeutic opportunities for cerebral edema after resuscitation
2022, ResuscitationRisk factors for development of cerebral edema following cardiac arrest
2022, ResuscitationCitation Excerpt :Hyperglycemia increases intracellular acidosis during CA and has been associated with increased mortality and poor neurological outcome in patients with CA.27–29 While correction of hyperglycemia has reduced mortality and improved functional outcomes, others have demonstrated that severity of illness plays a significant role in recovery of patients with mild-to-moderate cerebral edema when compared to modifiable risk factors like hyperglycemia.30–33 Hyperglycemia is common following CA, and it is unclear if it is a marker or a mediator of poor prognosis.
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2022, ResuscitationCitation Excerpt :Importantly, that authors concluded that neuroimaging interpretation discrepancies between radiology and neurointensivists were common and agreement on the severity of HIBI on early brain CT is poor. The Pittsburgh group has studied 214 comatose OHCA patients with a grey to white matter ratio (GWR) of 1.2–1.3 (deemed to indicate mild to moderate cerebral oedema) on initial brain CT (median 3.8 h after collapse).98 In adjusted analysis, none of the potentially modifiable processes of care predefined by the group (hypothermic temperature control, mean arterial pressure, PaO2, PaCO2, hypertonic medication) were independently associated with outcome.
Reply to: Prognostication in postanoxic coma: Not too early, not too late
2021, Resuscitation