Vascular Surgery Patients Prescribed Preoperative β-Blockers Experienced a Decrease in the Maximal Heart Rate Observed During Induction of General Anesthesia

ObjectiveTo investigate the association of preoperative β-blocker usage and maximal heart rates observed during the induction of general anesthesia.DesignRetrospective descriptive, univariate, and multivariate analyses of electronic hospital and anesthesia medical records.SettingA tertiary-care medical center within the Veterans Health Administration.ParticipantsConsecutive adult elective and emergent patients presenting for vascular surgery during calendar years 2005 to 2011.InterventionsNone.Measurements and Main ResultsOf the 430 eligible cases, 218 were prescribed β-blockers, and 212 were not taking β-blockers. The two groups were comparable across baseline patient factors (ie, demographic, morphometric, surgical duration, and surgical procedures) and induction medication doses. The β-blocker group experienced a lower maximal heart rate during the induction of general anesthesia compared with the non–β-blocker group (105 ± 41 beats/min v 115 ± 45 beats/min, respectively; p < 0.01). Adjusted linear regression found a statistically significant association between lower maximal heart rate and the use of β-blockers (β = −11.1 beats/min, p < 0.01). There was no difference between groups in total intraoperative β-blocker administration.ConclusionsPreoperative β-blockade of vascular surgery patients undergoing general anesthesia is associated with a lower maximal heart rate during anesthetic induction. There may be potential benefits in administering β-blockers to reduce physiologic stress in this surgical population at risk for perioperative cardiac morbidity. Future research should further explore intraoperative hemodynamic effects in light of existing practice guidelines for optimal medication selection, dosage, and heart rate control.