Autonomic Dysfunction and Adrenal Insufficiency in Thoracic Spine Tuberculosis

Abstract

While autonomic dysfunction has been reported in patients with spinal TB, little is known of the consequences. We matched 25 paraplegic patients with thoracic spine tuberculosis scheduled for spinal surgery (Group S) with 25 nontubercular American Society of Anesthesiologists Grade I patients scheduled for nonspinal surgeries (Group C) under identical operative conditions. All patients underwent four autonomic tests in the operating room, and a preoperative adrenocorticotropic hormone stimulation test was performed for patients in Group S. Compared to Group C, Group S had higher resting heart rate (103 +/- 20 beats/minute versus 81 +/- 10 beats/minute), lower expiratory:inspiratory ratio (1.14 +/- 0.11 versus 1.22 +/- 0.10), and higher heart rate variability (20 +/- 12 beats/minute versus 14 +/- 7 beats/minute), indicating probable parasympathetic dysfunction along with a relative sympathetic overactivity. Eight of the 17 patients who received an adrenocorticotropic hormone stimulation test had evidence of adrenal insufficiency. Incidence of hypotension in Group S and Group C was 100% and 44%, respectively. Mean systolic and diastolic blood pressure in Group S showed substantial decrease after induction and positioning of patients not associated with compensatory tachycardia. Coexisting pulmonary tuberculosis appears an important determinant of surgical approach as well as postoperative respiratory morbidity.