Acute baroreflex-mediated hemodynamic instability during thyroid surgery: A case report

Effectiveness of the oral Clonidine as a pre-anesthetic medicine for thyroidectomy surgery; A randomized clinical trial

Introduction

Hemodynamic disturbance is a common problem in patients undergoing thyroid surgery. It may be due to episodic increases in thyroid hormones (thyroid storm) or stimulation of the carotid sinus baroreflex. The aim of the present study was to investigate effectiveness of the pre-operative oral Clonidine on reducing these hemodynamic changes during total thyroidectomy surgery.

Methods

In a prospective, randomized, double-blind study, 80 patients scheduled for elective total thyroidectomy were randomized to receive either 0.2 mg Clonidine (n=40) or a matched placebo (n=40) orally sixty minutes before entering the operating room. Hemodynamic variables, the duration of surgery, estimated amount of blood loss and the dose of administered remifentanil were recorded for further analysis.

Results

Oral Clonidine was found to be significantly better in maintaining stable hemodynamics compared to the control group. Also, In the Clonidine group, the estimated amount of blood loss (110.4±10 ml vs. 182.2±11.4 mL, P=0.04), duration of the surgery (78.26±55.2 min vs. 105.16±61.75 min, P=0.027) and administered dose of remifentanil (26.67±6.6 μg vs. 216.2±14.8 μg, P=0.01) were also significantly lower than the control group.

Conclusion

Pre-operative administration of 0.2 mg oral Clonidine in patients undergoing total thyroidectomy results in improved perioperative hemodynamic stability and reduced response to perioperative stress.

Hemodynamic Instability during Thyroidectomy in Graves' Disease

BACKGROUND

The aim of this study was to investigate the changes in vital signs and hemodynamic status that occur in patients during the intraoperative course of thyroidectomy in Graves' Disease (GD).

METHODS

A total of 71 patients were included in the study. Patients were directed to surgery when they had large goiters with compressive symptoms or suspicious nodules, were pregnant or lactating, were unresponsive or intolerant to antithyroid drugs (ATDs), or expressed a preference to have surgery. All patients scheduled for operations underwent surgery while in the euthyroid state.

RESULTS

Hemodynamic instability was observed in 18 patients during thyroidectomy. Disease duration, sample weight, and thyroid-stimulating hormone receptor antibodies (TRAb) levels were found to be effective on hemodynamic instability. Logistic regression analysis revealed an 11-fold increase in the instability risk in patients with a period of disease shorter than 21 months (P = 0.037). A TRAb value >11.5 increased the risk by 235fold (p < 0.001).

CONCLUSION

High levels of TRAb values and new onset of disease with shorter periods of ATDs use may be risk factors for hemodynamic instability during thyroidectomy. Patients with larger thyroid glands are at greater risk for instability during surgery. Those risks should be taken into account during surgery, and the surgical and anesthetic management of the patient should be made more carefully in concordance with the anesthesia team.