Relationship of cardiovascular complications with level of consciousness in patients with acute carbamazepine intoxication.

Background: Carbamazepine is an iminostilbene derivative structurally related to cyclic antidepressants which implies its potential cardiotxic properties, especially in acute poisoning. This study aimed to determine the frequency and severity of cardiovascular complications in carbamazepine intoxication and its relationship with level of consciousness.

Methods: Patients with carbamazepine intoxication referred to our department recruited using convenience sampling method. Analysis included following parameters: systolic (SBP) and diastolic (DBP) blood pressure, ECG parameters: heart rate (HR), QRS width, PR interval and corrected QT interval (QTc). Relations between features on admission, 12 and 24 hours later and level of consciousness evaluated.

Results: 77 patients (28 males, 49 females; median age 25.1) which got our criteria included in this study. QRS complexes in 9 cases (11.7%) were wider than normal and PR interval and corrected QT interval (QTc) were normal. There was no significant relationship between QT interval, QRS width and pulse rate changes with level of consciousness during 24 hours post admission, but blood pressure [systolic, diastolic and mean arterial blood pressure (MABP)] progressively decreased and PR interval changes progressively increased during this period. Further, there was negative correlation just between sever decrease of level of consciousness (coma) and blood pressure [systolic, diastolic and mean arterial blood pressure (MABP)], and positive correlation with QRS complexes widening at 12 hours after admission. There was no correlation between loss of consciousness and diastolic blood pressure, QT interval and PR interval on admission and 12 hours and 24 hours later.

Conclusion: Regarding the relationship between level of consciousness and cardiovascular changes at 12 hours after admission, particular attention on cardiovascular changes and ECG monitoring particularly in intoxicated patients with severe loss of consciousness(coma), should considered; it will lead to prevent unexpected complication, mortality and to decrease the length of hospitalization.