The Validity of Poisoning Severity Score in Acute Carbon Monoxide Intoxicated Patients

Background and Objective: The poisoning severity score is a standardized and generally applicable scheme for grading the severity of poisoning. It allows a qualitative evaluation of morbidity and facilitates comparability of data. The aim of this study was to evaluate the validity of the poisoning severity score in patients with acute carbon monoxide poisoning as a result of their descriptive, laboratory, clinical data and outcome.

Subjects and Methods: An observational prospective study design was used in the data collection process for eighty Co poisoned patients who presented to Poison Control Center (PCC), Ain Shams University Hospital, Egypt over six months. Patients with coronary artery disease or other known heart disease, patients with renal failure as well as smoker subjects were excluded. The patients were divided into 3 grades according to the poisoning severity score (PSS) which was applied to all patients in the present study at the emergency department. Also a group consisted of twenty apparently healthy nonsmoker volunteers (of matched age and sex) were served as a control group. Arterial blood gases (ABG), carboxyhemoglobin level (COHb), random blood sugar, serum of sodium (Na), potassium (K), alanine aminotransferase (ALT), serum creatine phosphokinase (CPK), serum urea and creatinine, hematological parameters (red blood cells, white blood cells and hemoglobin), serial cardiac markers (serum of aspartate aminotransferase (AST), creatine kinase-MB, lactate dehydrogenase (LDH), and cardiac troponin-I (cTnI) quantitative determination and ECG however brain CT scan was done only for cases who admitted to ICU.

Results: Higher mean delay time, tachycardia, bradypnea, respiratory distress, pulmonary edema, lowest mean GCS, hypernatremia, leukocytosis, acidosis, hyperglycemia, high levels of CPK- MB, AST and cTnI, ECG changes, abnormal CT (infarction and brain edema) at presentation and the need of mechanical ventilation with hyperbaric oxygen showed significant relation with higher PSS and adverse outcome.

Conclusion: Age, delay time, PSS grade, Glucose, AST, CPK-MB and Cardiac Troponin I are significant predictors of outcome. These results indicated that those variables are the most important factors for determining the outcome within the limitations of our study. So the results of the present study revealed that PSS is reliable severity score for diagnosis, management and prognosis of COP cases especially with the added modifications in the form of laboratory, ECG and brain CT scan.