Crisis management during anaesthesia: tachycardia.

BACKGROUND: Tachycardia during anaesthesia is a common event. In most cases the cause is easily identified and the problem promptly resolved. However, in some the cause may be rare or obscure. Under such circumstances, attempting to initiate appropriate supportive therapy and to consider a large differential diagnosis in a comprehensive manner may lead to delays which can put a patient at risk.
OBJECTIVES: To examine the role of a previously described core algorithm "COVER ABCD-A SWIFT CHECK", supplemented by a specific sub-algorithm for tachycardia, in the management of tachycardia developing in association with anaesthesia.
METHODS: The potential performance of this structured approach for each of the relevant incidents among the first 4000 reported to the Australian Incident Monitoring Study (AIMS) was compared with the actual management as reported by the anaesthetists involved.
RESULTS: There were 145 causative events identified in 123 reports of tachycardia during anaesthesia which were extracted and studied from the first 4000 incidents reported to AIMS. Subgroups were identified based on blood pressure at the time of presentation. Of the 145 causes, tachycardia was associated with hypotension (33%), normotension (27%), hypertension (26%), and cardiac arrest (17%). For simplicity it is recommended that other cardiovascular sub-algorithms are followed when the blood pressure is also abnormal. This includes cardiac arrest and hypotension. In hypotensive states the tachycardia sub-algorithm should be followed until the cardiac rhythm is diagnosed. Sinus tachycardia and hypotension should be managed as hypotension. It was considered that, correctly applied, the core algorithm COVER would have diagnosed 35% of cases and led to resolution in 70% of these. It was estimated that completion of COVER followed by the sub-algorithm for tachycardia would have led to earlier recognition of the problem and/or better management in four cases when compared with actual management reported.
CONCLUSION: Tachycardia during anaesthesia is frequently associated with a simultaneous change in other monitored vital signs. The differential diagnosis is large. Addressing it in a comprehensive fashion requires a structured approach. A specific sub-algorithm treatment for tachycardia based on the associated blood pressure and on the prevailing heart rhythm in the case of hypotension offers a systematic guide which complements the benefits obtained by employing the core algorithm COVER ABCD.