Arrhythmias in prone position.

Sir,

We read with interest the article by Dube et al. on frequent ventricular premature contractions in a patient in prone position.[1] Although the case was managed uneventfully, we have few concerns related to its management.

Firstly, though the ventricular premature contractions (VPCs) were controlled with lignocaine, the cause was not established. It is possible that the endotracheal tube moved when the patient was positioned prone and the tip touched the carina. Carinal stimulation is a known cause of VPCs.[2]

Secondly, VPCs occurred just after placing the patient in prone position. Surgery had not yet commenced and the cause was not identified. VPCs were of new onset and frequent (>5/ min). In this scenario, it may have been prudent to reposition the patient to supine, discontinue anesthetics and search for a cause, as treating the underlying cause is the first step in management of VPCs.

New onset VPCs should be considered life threatening. Anesthetic agents can cause VPCs. The authors attributed isoflurane as a probable cause of the arrhythmia but the anesthetic technique was not modified. Isoflurane has been implicated to increase the incidence of arrhythmia in patients with coronary perfusion compromise.[3] It is prudent to evaluate the cause of such rhythm disturbances before starting the surgical procedure. The patient reported had a favorable outcome but this does not imply that the outcome is likely to be favorable in all or most of the cases.