Usefulness of the NULL-PLEASE Score to Predict Survival in Out-of-Hospital Cardiac Arrest

Abstract

Out-of-hospital cardiac arrest (OHCA) carries a very high mortality rate even after successful cardiopulmonary resuscitation. Currently, information given to relatives about prognosis following resuscitation is often emotive and subjective, and varies with clinician experience. We aimed to validate the NULL-PLEASE score to predict survival following OHCA. METHODS: A multicenter cohort study was conducted, with retrospective and prospective validation in consecutive unselected patients presenting with OHCA. The NULL-PLEASE score was calculated by attributing points to the following variables: Nonshockable initial rhythm, Unwitnessed arrest, Long lowflow period, Long no-flow period, pH <7.2, Lactate >7.0 mmol/L, End-stage renal failure, Age ≥85 years, Still resuscitation, and Extracardiac cause. The primary outcome was in-hospital death. RESULTS: We assessed 700 patients admitted with OHCA, of whom 47% survived to discharge. In 300 patients we performed a retrospective validation, followed by prospective validation in 400 patients. The NULL-PLEASE score was lower in patients who survived compared with those who died (0 [interquartile range 0-1] vs 4 [interquartile range 2-4], P < .0005) and strongly predictive of in-hospital death (C-statistic 0.874; 95% confidence interval, 0.848-0.899). Patients with a score ≥3 had a 24-fold increased risk of death (odds ratio 23.6; 95% confidence interval, 14.840-37.5; P < .0005) compared with those with lower scores. A score ≥3 has a 91% positive predictive value for in-hospital death, while a score <3 predicts a 71% chance of survival. CONCLUSION: The easy-to-use NULL-PLEASE score predicts in-hospital mortality with high specificity and can help clinicians explain the prognosis to relatives in an easy-to-understand, objective fashion, to realistically prepare them for the future.

Scoring Systems to Predict Survival or Neurological Recovery after Out-of-hospital Cardiac Arrest

“…The score has been externally validated in a UK multicentre cohort of 700 patients (300 retrospective and 400 prospective), demonstrating a c-statistic of 0.874 (95% CI [0.848–0.899]). [ 19 ] It has been further externally validated in a recent retrospective cohort of 189 patients, with a c-statistic of 0.874 (95% CI [0.807–0.942]) for prediction of in-hospital mortality. [ 20 ] A key disadvantage of the score is the reliance on pH and lactate, which may not always be available, and the use of other variables such as no-flow and low-flow times, which are often inaccurately recorded.…”

Predicting neurological outcome in adult patients with cardiac arrest: systematic review and meta-analysis of prediction model performance

“…The rCAST score was developed for use in patients treated with targeted temperature management only[ 69 ] and was therefore not included in our meta-analysis. The NULL-PLEASE score[ 70 ] is a CPM very similar to the OHCA and CAHP scores and has shown potential in some validation studies [ 56 , 59 , 71 , 72 ].…”

Out-of-hospital cardiac arrest: A systematic review of current risk scores to predict survival

“…Recent independent external validation in a contemporary cohort (26) shows an AUC of 0.874 for predicting in-hospital mortality. A score of ≥3 has a specificity of 93.4% but low sensitivity at 57.3%.…”