Rapid onset of haemodynamic effects after angiotensin converting enzyme-inhibitor overdose: implications for initial patient triage.

BACKGROUND: Angiotensin converting enzyme (ACE)-inhibitor overdose may result in severe hypotension. Existing data do not adequately deal with the likely onset of haemodynamic effects, which has implications for the appropriate duration of monitoring in the acute-care setting. Therefore, the relationship between the interval after an ACE-inhibitor overdose and onset of hypotension was examined.
METHODS: A retrospective case review of patients who attended our institution after an ACE-inhibitor overdose between 1 January 2000 and 31 December 2005 was carried out. Data collected were heart rate, blood pressure, electrolytes, electrocardiogram variables, and interval between ingestion and lowest recorded blood pressure.
RESULTS: 33 patients (24 men) who presented after an ACE-inhibitor overdose were identified. Median (interquartile range (IQR)) age was 49 (42-56) years, and stated quantity ingested was 20 (7-42) times the defined daily dose. The median (IQR) interval between ACE-inhibitor ingestion and lowest recorded systolic blood pressure was 4.5 (3.8-5.5) h, diastolic blood pressure was 3.8 (3.3-6.5) h and mean blood pressure was 4.2 (3.5-5.5) h. Heart rate did not increase substantially in response.
CONCLUSION: The lowest blood pressure was recorded within a short interval after an ACE-inhibitor overdose, irrespective of therapeutic intervention. Patients in whom hypotension has not occurred within 6 h of ingestion can be considered for discharge.