Effects of esmolol continuous infusion on blood loss in patients undergoing posterior lumbar internal fixation surgery: A prospective randomized study

Abstract

Objective: To determine the intravenous (i.v.) dose of esmolol needed to attenuate blood loss in patients undergoing posterior lumbar internal fixation (PLIF) surgery.

Methods: This study randomized patients to either the E5 or E10 group. Patients in the E5 group received a 0.25 mg/kg i.v. loading dose of esmolol before anaesthesia, followed by an infusion of 5 µg/kg/min throughout the operation. Patients in the E10 group received a 0.5 mg/kg i.v. loading dose of esmolol before anaesthesia, followed by an infusion of 10 µg/kg/min throughout the operation.

Results: The study analysed 33 patients: 16 in the E5 group and 17 in the E10 group. The mean ± SD blood loss at the end of surgery was significantly greater in the E5 than E10 group (586.3 ± 160.1 versus 347.7 ± 138.0 ml, respectively). The total amount of patient-controlled analgesia (PCA) used was significantly higher in the E5 than E10 group at 8 (26.1 ± 12.0 versus 17.5 ± 8.3 ml, respectively), 24 (58.4 ± 21.3 versus 44.1 ± 16.2 ml, respectively) and 48 h after surgery (90.0 ± 22.5 versus 69.3 ± 22.1 ml, respectively).

Conclusion: A continuous infusion of 10 µg/kg/min of esmolol can safely reduce blood loss during PLIF surgery. It was also shown to reduce postoperative PCA consumption.

Keywords: Spine surgery; blood loss; esmolol; pain.

Figure 1.

Flow diagram showing the progress through enrolment, randomization and analysis of adult patients (n = 36) scheduled for posterior lumbar internal fixation surgery (2–3 levels) that were enrolled in a study investigating the optimal intravenous concentration of esmolol.

Figure 2.

Changes in vital signs of adult patients (n = 33) scheduled for posterior lumbar internal fixation surgery (2–3 levels) that were enrolled in a study investigating the optimal intravenous concentration of esmolol. Data presented as mean ± SD. SBP, systolic blood pressure; T0, baseline; T1, just before surgical incision; T2, 1 h after surgical incision; T3, 2 h after surgical incision; T4, at the end of surgery; DBP, diastolic blood pressure; HR, heart rate, bpm, beats per min.

Figure 3.

Changes in cardiac parameters of adult patients (n = 33) scheduled for posterior lumbar internal fixation surgery (2–3 levels) that were enrolled in a study investigating the optimal intravenous concentration of esmolol. Data presented as mean ± SD. CO, cardiac output; T1, just before surgical incision; T2, 1 h after surgical incision; T3, 2 h after surgical incision; T4, at the end of surgery; CI, cardiac index.

Figure 4.

Visual analogue scale (VAS) pain scores and analgesia infusion volumes of adult patients (n = 33) scheduled for posterior lumbar internal fixation surgery (2–3 levels) that were enrolled in a study investigating the optimal intravenous concentration of esmolol. Data presented as mean ± SD. P0, at the time of discharge from the postanaesthesia care unit; P2, 2 h after transfer to general ward; P8, 8 h after transfer to general ward; P24, 24 h after transfer to general ward; P48, 48 h after transfer to general ward; PCA, patient-controlled analgesia. *P < 0.05, between-group comparison; Student’s t-test.