Figure 1.

Resistance to first-line benzodiazepine treatment increases with the duration of status epilepticus and is associated with increased morbidity. (A) Proportion of paediatric patients presenting with convulsive status epilepticus (CSE) resistant (benzodiazepine-resistant, bzpR, red) or sensitive (benzodiazepine-sensitive, bzpS, black) to first-line treatment with benzodiazepines. (B) Benzodiazepine resistance was associated with longer hospital stays (benzodiazepine-sensitive: median 4.00 IQR 1.0–2.0 days versus benzodiazepine-resistant: median 4.0 days IQR 1.0–9.50 days, P < 0.0001, Mann-Whitney U-test) and (C) these patients were more likely to require admission to the paediatric intensive care unit [PICU, odds ratio (OR) = 47.57, 95% confidence interval (CI): 6.24–362.9, P < 0.0001, Fisher's exact test]. (D) There was no difference in underlying aetiology between the groups when dividing causes into four categories: ‘Acute’, acute illness; ‘Remote’, previous brain injury; ‘Syndrome’, established electroclinical syndrome; ‘Unknown’, no aetiology found during admission (P = 0.25, χ² test). (E) Top: Cumulative frequency plot of benzodiazepine-resistant (red) and benzodiazepine-sensitive (black) patients as a function of seizure duration prior to treatment (benzodiazepine-resistant: median 40.0 IQR 28.0–52.0 min versus benzodiazepine-sensitive: median 65.00 IQR 45.0–95.0 min, P < 0.0001, Mann-Whitney U-test). Bottom: Increased status epilepticus duration is associated with enhanced probability of benzodiazepine resistance. The optimum discrimination threshold for separating benzodiazepine-resistant from benzodiazepine-sensitive patients calculated using data in F is indicated by the grey dashed line. (F) ROC curve analysing how well the status epilepticus duration classifies the likelihood of benzodiazepine sensitivity or resistance. Top right corresponds to short status epilepticus durations; bottom left to long status epilepticus durations. The maximal difference between the true and false positive rates occurs when the classifier is set at 61 min (grey circle).