Postoperative analgesic effect, of preoperatively administered dexamethasone, after operative fixation of fractured neck of femur: randomised, double blinded controlled study

Abstract

Background: Fractured neck of femur is a common cause of hospital admission in the elderly and usually requires operative fixation. In a variety of clinical settings, preoperative glucocorticoid administration has improved analgesia and decreased opioid consumption. Our objective was to define the postoperative analgesic efficacy of single dose of dexamethasone administered preoperatively in patients undergoing operative fixation of fractured neck of femur.

Methods: Institutional ethical approval was granted and written informed consent was obtained from each patient. Patients awaiting for surgery at Cork University Hospital were recruited between July 2009 and August 2012. Participating patients, scheduled for surgery were randomly allocated to one of two groups (Dexamethasone or Placebo). Patients in the dexamethasone group received a single dose of intravenous dexamethasone 0.1 mg kg -1 immediately preoperatively. Patients in the placebo group received the same volume of normal saline. Patients underwent operative fixation of fractured neck of femur using standardised spinal anaesthesia and surgical techniques. The primary outcome was pain scores at rest 6 h after the surgery.

Results: Thirty seven patients were recruited and data from thirty patients were analysed. The groups were similar in terms of patient characteristics. Pain scores at rest 6 h after the surgery (the principal outcome) were lesser in the dexamethasone group compared with the placebo group [0.8(1.3) vs. 3.9(2.9), mean(SD) p = 0.0004]. Cumulative morphine consumption 24 h after the surgery was also lesser in the dexamethasone group [7.7(8.3) vs. 15.1(9.4), mean(SD) mg, p = 0.04].

Conclusions: A single dose of intravenous dexamethasone 0.1 mg kg -1 administered before operative fixation of fractured neck of femur improve significantly the early postoperative analgesia.

Trial registration: ClinicalTrials.gov identifier: NCT01550146 , date of registration: 07/03/2012.

Keywords: Analgesics; Dexamethasone; Intravenous injections.

Figures

Fig. 1

Flow diagram, showing data about enrollment, allocation, follow-up and statistical analysis

Fig. 2

Showing Numeric rating scale (NRS) pain scores at rest in the first postoperative week. Primary outcome is NRS pain score 6 h after the surgery

Fig. 3

Showing Numeric rating scale (NRS) pain scores on passive movement in the first postoperative week

Fig. 4

Showing cumulative morphine consumption in the first postoperative week. Placebo group (red), Dexamethasone group (green)