The Curing Coma Campaign International Survey on Coma Epidemiology, Evaluation, and Therapy (COME TOGETHER)

Abstract

Background: Although coma is commonly encountered in critical care, worldwide variability exists in diagnosis and management practices. We aimed to assess variability in coma definitions, etiologies, treatment strategies, and attitudes toward prognosis.

Methods: As part of the Neurocritical Care Society Curing Coma Campaign, between September 2020 and January 2021, we conducted an anonymous, international, cross-sectional global survey of health care professionals caring for patients with coma and disorders of consciousness in the acute, subacute, or chronic setting. Survey responses were solicited by sequential emails distributed by international neuroscience societies and social media. Fleiss κ values were calculated to assess agreement among respondents.

Results: The survey was completed by 258 health care professionals from 41 countries. Respondents predominantly were physicians (n = 213, 83%), were from the United States (n = 141, 55%), and represented academic centers (n = 231, 90%). Among eight predefined items, respondents identified the following cardinal features, in various combinations, that must be present to define coma: absence of wakefulness (81%, κ = 0.764); Glasgow Coma Score (GCS) ≤ 8 (64%, κ = 0.588); failure to respond purposefully to visual, verbal, or tactile stimuli (60%, κ = 0.552); and inability to follow commands (58%, κ = 0.529). Reported etiologies of coma encountered included medically induced coma (24%), traumatic brain injury (24%), intracerebral hemorrhage (21%), and cardiac arrest/hypoxic-ischemic encephalopathy (11%). The most common clinical assessment tools used for coma included the GCS (94%) and neurological examination (78%). Sixty-six percent of respondents routinely performed sedation interruption, in the absence of contraindications, for clinical coma assessments in the intensive care unit. Advanced neurological assessment techniques in comatose patients included quantitative electroencephalography (EEG)/connectivity analysis (16%), functional magnetic resonance imaging (7%), single-photon emission computerized tomography (6%), positron emission tomography (4%), invasive EEG (4%), and cerebral microdialysis (4%). The most commonly used neurostimulants included amantadine (51%), modafinil (37%), and methylphenidate (28%). The leading determinants for prognostication included etiology of coma, neurological examination findings, and neuroimaging. Fewer than 20% of respondents reported routine follow-up of coma survivors after hospital discharge; however, 86% indicated interest in future research initiatives that include postdischarge outcomes at six (85%) and 12 months (65%).

Conclusions: There is wide heterogeneity among health care professionals regarding the clinical definition of coma and limited routine use of advanced coma assessment techniques in acute care settings. Coma management practices vary across sites, and mechanisms for coordinated and sustained follow-up after acute treatment are inconsistent. There is an urgent need for the development of evidence-based guidelines and a collaborative, coordinated approach to advance both the science and the practice of coma management globally.

Keywords: Coma; Critical care; Disorders of consciousness; Survey.

Fig. 1

Countries of respondents contributing to the survey. The figure displays the number of respondents per country given in percentages

Fig. 2

Agreement on the definition of coma (n = 238 respondents) based on Table 1. Bars reflect the percentage of agreement/disagreement for the overall definition of coma and each subfeature (1–6) provided in Table 1. Survey question: To what degree do you agree with the definition of coma as described above (1 = “I fully agree” to 10 = “I fully disagree”)?

Fig. 3

Most common etiologies of coma weighted by the five most common causes. Survey question: Rank the top five most common etiologies of coma that you encounter in your institution based on the definition of coma provided above. Bars represent the selection of etiologies based on the most common (blue), second most common (orange), third most common (gray), fourth most common (yellow), fifth most common (light blue) etiology of coma. Data are given in percentage and weighted based on the grading of respondents, normalized to the most common etiology (intracerebral hemorrhage). The answers were weighted based on the most common (multiplied by 5), the second most common (multiplied by 4), the third most common (multiplied by 3), the fourth most common (multiplied by 2) and the 5th most common etiology (multiplied by 1)

Fig. 4

Diagnostic tools in the evaluation of comatose (≥ 24 h) patients (n = 236/258). Survey question: Which of the following tools do you routinely use in the diagnostic evaluation of these patients in coma (present ≥ 24 h)? CT, computed tomography; CTA, CT angiography; CTP, CT perfusion; MRI, magnetic resonance imaging; MRA, MR angiography; MRP, MR perfusion; EEG, electroencephalography; ICP, intracranial pressure; SPECT, single-photon emission computerized tomography; PET, positron emission tomography

Fig. 5

a Elements commonly used to prognosticate in coma patients (n = 226 of 258). Most important prognostic factors (first) were the etiology of coma (n = 87 of 226, 38%), findings in neurological examination (n = 70 of 226, 31%) and age (n = 29 of 226, 13%). The top three most important factors were etiology of coma (n = 170 of 226, 75%), findings in neurological examination (n = 149 of 226, 66%) and neuroimaging (n = 115 of 226, 51%). Bars represent the cumulative incidence for ranking the top three elements used for prognostication normalized to “etiology of coma” (100%). Survey question: Please rank the top three (first, second, third) most important elements you utilize for prognostication in comatose patients. The answers were weighted based on the most common (multiplied by 3), the second most common (multiplied by 2), the third most common (multiplied by 1). b Areas of coma research for coma patients. Survey question: What areas of coma research focus do you feel are most important/urgent? The answers were weighted based on the most common (multiplied by 3), the second most common (multiplied by 2), the third most common (multiplied by 1)