Predictors for Intensive Care Unit Admission in Patients with Acute Clozapine Toxicity

Background: Clozapine is an atypical antipsychotic medication commonly used in the management of treatment-resistant schizophrenia. Acute clozapine toxicity is a potentially life-threatening condition. So, we aimed to identify clinical predictors for intensive care unit (ICU) admission in adult patients with acute clozapine toxicity which are essential for timely triage, optimizing resource utilization, and improving patient outcomes. Methods: A prospective cohort study was carried out on 60 adult patients of acute clozapine toxicity presented to Zagazig University Hospitals. Patients were evaluated by 1] A thorough history of ingested clozapine dose and time passed since ingestion. 2] Clinical assessment of vital signs, agitation, chest secretion, Poisoning Severity Score (PSS) and Body Mass Index (BMI). 3] Laboratory investigations: arterial blood gases, electrolytes and cardiac biomarkers (CK-MB, Troponin I and Troponin T). 4] ECG. Results: The results of the study showed that there was statistically significant increase in ingested clozapine dose, time lapse from ingestion to hospital arrival, PSS, BMI, cardiac biomarkers level, and ECG abnormalities and statistically significant decrease in pH, HCO3 levels and oxygen saturation in patients admitted to ICU than those who did not. Cardiac biomarkers, PSS and BMI showed good diagnostic performance, on ROC, curve as predictors for ICU admission. Conclusion: The results of the study concluded that cardiac biomarkers, PSS ≥2 and BMI ≥27 followed by clozapine ingested dose ≥450 mg and delayed hospital presentation ≥ 4.5 hours are good predictors for ICU admission in acute clozapine toxicity.