Conflict of Interest Declaration
The ILCOR Continuous Evidence Evaluation process is guided by a rigorous ILCOR Conflict of Interest policy. The following Task Force members and other authors were recused from the discussion as they declared a conflict of interest: none
The following Task Force members and other authors declared an intellectual conflict of interest and this was acknowledged and managed by the Task Force Chairs and Conflict of Interest committees: Claudio Sandroni, Karen Hirsch, Jerry Nolan and Jasmeet Soar were coauthors of the systematic review used for adolopment. They did not participate in assessment of the systematic review for quality for adolopment.
Skrifvars M, Sandroni C, Hirsch K, on behalf of the ILCOR ALS Task Force, Use of the Glasgow Coma Scale motor score for the prediction of good outcome after cardiac arrest, Consensus on Science with Treatment Recommendations. Brussels, Belgium: International Liaison Committee on Resuscitation (ILCOR) Advanced Life Support Task Force, 2022 December 9. Available from: http://ilcor.org
Methodological Preamble and Link to Published Systematic Review
The continuous evidence evaluation process for the production of Consensus on Science with Treatment Recommendations (CoSTR) started with a systematic review of prognostication after cardiac arrest (PROSPERO: CRD 420 1914 1169). This review was conducted by a systematic review team with the involvement of clinical content experts from the ILCOR ALS Task Force and consisted of two parts. The first part was about prediction of poor neurological outcome and provided evidence for the 2021 ILCOR CoSTR. The second part was about prediction of good neurological outcome and it was completed after the publication of the 2021 ILCOR CoSTR. The two parts of this review have been published separately in 2020 and 2021 respectively (Sandroni C et al, DOIs 10.1007/s00134-020-06198-w and 10.1007/s00134-022-06618-z, respectively). As the systematic review on prognostication of favorable outcomes was recent and met ILCOR criteria for being of sufficient quality, the TF deemed it appropriate to use the adolopment process for systematic reviews. Additionally, an updated search including the dates October 31, 2021- May 20, 2022, to capture any papers published since the search for the original systematic review was conducted. Task force members screened and selected all newly identified papers, extracted data and performed bias assessment using the QUIPS tool, which was also used in the original systematic review. The totality of this identified evidence was considered by the Advanced Life Support task force and used to determine the certainty of evidence and formulate the Consensus on Science and Treatment Recommendations.
Webmaster to insert the Systematic Review citation and link to Pubmed using this format when it is available if published
Sandroni C, D'Arrigo S, Cacciola S, Hoedemaekers CWE, Westhall E, Kamps MJA, Taccone FS, Poole D, Meijer FJA, Antonelli M, Hirsch KG, Soar J, Nolan JP, Cronberg T. Prediction of good neurological outcome in comatose survivors of cardiac arrest. A systematic review. DOI: 10.1007/s00134-022-06618-z.)
The PICOST (Population, Intervention, Comparator, Outcome, Study Designs and Timeframe)
Population: Population: Adults (≥16 y) who are comatose after resuscitation from cardiac arrest (either in-hospital or out-of-hospital), regardless of target temperature.
Intervention: Glasgow Coma Scale motor score evaluated within four days after cardiac arrest.
Outcomes: Prediction of good neurological outcome defined as Cerebral Performance Categories (CPC) 1-2 or modified Rankin Score (mRS) 1-3 at hospital discharge/1 month or later.
Study Designs: Prognostic accuracy studies where the 2 x 2 contingency table (i.e., the number of true/false negatives and positives for prediction of poor outcome) was reported, or where those variables could be calculated from reported data, are eligible for inclusion. Unpublished studies, reviews, case reports, case series, studies including less than 10 patients, letters, editorials, conference abstracts, and studies published in abstract form were excluded.
Timeframe: In 2015 and 2020, ILCOR evidence reviews identified four categories of predictors of poor neurological outcome after cardiac arrest, namely clinical examination, biomarkers, electrophysiology, and imaging. However, the prediction of good neurological outcome has never been systematically reviewed to date. We searched studies published from January 1, 2001, onwards. Our last search was on May 20th 2022.
PROSPERO Registration CRD42017080475
Consensus on Science
The original systematic review identified two observational studies on the prediction of good outcome using the GCS motor score on admission and within the first four days. The overall risk of bias was moderate in one study [Moseby-Knappe 2020 1852] and high in one study [Hifumi 2015 2201]. The studies included 342 [Moseby-Knappe 2020 1852] and 302 [Hifumi 2015 2201] out-of-hospital cardiac arrest patients. In both studies the clinical examination was done off-sedation.
The overall certainty of the evidence was rated as very low (downgraded for risk of bias, imprecision and indirectness). Due to a high degree of heterogeneity between the two studies and the use of two different time-points for the assessment, we did not perform meta-analyses.
In one study [Moseby-Knappe, 2020 1852] a GCS motor score > 3 on day 4 after cardiac arrest predicted favorable outcome at 6-months with a specificity of 84% (95% CI 79-88%) and a sensitivity of 77% (95% CI 67-85%). In the same study, a GCS motor score 3–5 on day 4 predicted favorable outcome with 72% (95% CI 66-77%) specificity and 96% (95% CI 93-97%) sensitivity.
In one study [Hifumi, 2015 2201] a GCS motor score 4–5 evaluated on ICU admission after cardiac arrest predicted favorable outcome at 3-months with specificity of 98% (95% CI 93-99%) and sensitivity of 12% (95% CI 7-17%).
We suggest assessing the Glasgow Coma Scale motor score in the first four days after cardiac arrest to identify patients with a score higher than three, which may indicate an increased likelihood of favourable outcome (weak recommendation, very low certainty of evidence).
Justification and Evidence to Decision Framework Highlights
- There are only two studies assessing the value of the GCS motor score in post-cardiac arrest patients. The evidence suffers from problems with imprecision as the sensitivities and specificities have wide confidence intervals and vary a great deal between studies. In addition, there is the problem of indirectness as most studies have included only patients included in interventional randomized controlled trials with strict inclusion criteria. For example, there is little evidence in patients with a non-cardiac cause of the arrest.
- The effect of administered sedation and pain medication may influence the assessment of the GCS motor score and the waiting time after stopping such medications to achieve a reliable test result may vary between patients.
- The assessment of the GCS motor score is an integral part of the identification of those unconscious patients who should undergo prognostication tests after cardiac arrest [Soar, 2020]. Using the GCS motor score to identify those with a better motor response is not likely to have undesirable effects.
- Importantly any possible withdrawal of life sustaining therapies in post-cardiac arrest patients should be undertaken using several prognostication modalities according to the 2020 COSTR on the prediction of poor outcome [Soar, 2020].
- The value of early assessment of the GCS motor score is unclear. Early assessment and a GCS motor score higher than three may be specific for predicting favourable outcome but the sensitivity was very low.
- Larger studies on the use of the GCS in post-cardiac arrest patients at various time-points are needed. In addition, there is a need to include in-hospital cardiac arrest patients as well as those with a non-cardiac cause of the arrest.
- The implication of the individual GCS motor score for the patient´s prognosis is currently unclear.
- Studies comparing the use of GCS motor score to other means of assessing the prognosis are needed. This includes studies assessing costs and cost-effectiveness.
- Studies on whether there is significant inter-rater variability between different health care professionals assessing the GCS motor score are needed.
Soar J, Berg KM, Andersen LW, Böttiger BW, Cacciola S, Callaway CW, Couper K, Cronberg T, D'Arrigo S, Deakin CD, Donnino MW, Drennan IR, Granfeldt A, Hoedemaekers CWE, Holmberg MJ, Hsu CH, Kamps M, Musiol S, Nation KJ, Neumar RW, Nicholson T, O'Neil BJ, Otto Q, de Paiva EF, Parr MJA, Reynolds JC, Sandroni C, Scholefield BR, Skrifvars MB, Wang TL, Wetsch WA, Yeung J, Morley PT, Morrison LJ, Welsford M, Hazinski MF, Nolan JP; Adult Advanced Life Support Collaborators. Adult Advanced Life Support: 2020 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science with Treatment Recommendations. Resuscitation. 2020 Nov;156:A80-A119. doi: 10.1016/j.resuscitation.2020.09.012. Epub 2020 Oct 21. PMID: 33099419; PMCID: PMC7576326.
Hifumi T, Kuroda Y, Kawakita K, et al. Effect of Admission Glasgow Coma Scale Motor Score on Neurological Outcome in Out-of-Hospital Cardiac Arrest Patients Receiving Therapeutic Hypothermia. Circ J. 2015;79(10):2201-8.
Moseby-Knappe, M., Westhall, E., Backman, S. et al. Performance of a guideline-recommended algorithm for prognostication of poor neurological outcome after cardiac arrest. Intensive Care Med 46, 1852–1862 (2020).