Hemodynamic instability following bilateral carotid endarterectomy

Background

Blood pressure (BP) and heart rate (HR) instability following carotid endarterectomy (CEA) have been extensively documented in the literature [1, 2]. CEA has been associated with disturbance of the baroreceptor control mechanism caused by surgery in the carotid sinus region [1]. Smit and colleagues reported bilateral carotid sinus denervation producing long-term blood pressure variability [3]. In our study, we report finding profound hemodynamic instability during the 24-hour period following CEA on four patients who had undergone a previous contralateral CEA (Group 1) and compare management of these patients with five controls who underwent CEA without previous contralateral CEA surgery (Group 2).

Methods

All patients underwent general endotracheal anesthesia with the same induction and maintenance regimen. BP and HR were recorded continuously perioperatively and for 24 hours postoperatively. Incidence of postoperative hypertension (HTN), hypotension, bradycardia, maximal increase in HR and the associated use of corrective medications were recorded.

Results

The incidence of refractory hypotension and bradycardia was higher in the bilateral CEA group (Group 1, n = 3/4), while in the unilateral CEA group (Group 2) hypotensive and bradycardic response was transient and readily reversible. All patients exhibiting refractory hemodynamic instability in Group 1 required aggressive management with sympathomimetic and parasympatholytic medications for a period of 24–36 hours postprocedure in the PACU and SICU. Hypertension was a prominent feature in three patients in Group 2 (n = 3/5) while one patient in Group 2 developed cardiac dysrhythmia that required cardioversion. Only one patient in both groups needed hospitalization longer than 72 hours on account of recurrent cardiac dysrhythmia.

Conclusion

Not withstanding the small sample size, our results indicate that bilateral CEA is associated with significant hemodynamic instability and often requires aggressive pharmacotherapy. Awareness, early diagnosis and prompt treatment improve outcome and often single out patients who need closer follow-up during the posthospitalization period. Our data showed that hemodynamic instability does not significantly affect early discharge [4] while intraoperative injection of bupivicaine at the carotid sinus level does not reduce the level of postoperative hypotension.