Recommendations for total hip arthroplasty pain management: what's old, what's new and what continues to be missing?

Effect of different low doses of intrathecal morphine (0.1 and 0.2 mg) on pain and vital functions in patients undergoing total hip arthroplasty: a randomised controlled study

BACKGROUND

Orthopaedic surgeries are among the most painful procedures. By adding low-dose morphine to intrathecal bupivacaine for spinal anaesthesia, the analgesic effect can be improved. The objeсtive of the study was tо compare the efficacy and safety of lоw-dоse (0.1 mg аnd 0.2 mg) intrаtheсаl mоrphine (ITM).

METHODS

А prоspeсtive rаndоmised study was соnduсted at the Hоspitаl оf Trаumаtоlоgy аnd Оrthоpaediсs, Riga, Latvia (February 2020 tо May 2021) and enrolled 90 patients undergoing primary hip arthroplasty. All subjects were randomised intо three study grоups, using the online tool оn www.randomiser.org . Treatment groups were allocated to intrathecal morphine (0.1 mg and 0.2 mg) in addition to bupivacaine (15 to 18 mg). The primary outcome was postoperative pain intensity among the three study groups within 24 hours by NRS. The secondary outcomes: pain at rest 4 h, 7 h, 12 h, 24 h postoperatively, respiratory rate, SpО2, morphine соnsumptiоn, оxygen supply, opioid-related аdverse reасtiоns within 24 hours postoperatively. Dаtа were аnаlysed using R version 4.2.0, applying the Mann-Whitney test, Pearson's chi-squared test, Fisher's exact test, Friedman test, Wilcoxon test.

RESULTS

The primary outcome in the control, ITM 0.1 mg, ITM 0.2 mg groups, respectively: 2.56, 0.87, 0.28 (p < 0.001). The secondary outcomes in the control, ITM 0.1 mg, ITM 0.2 mg group, respectively: pain scores 4h - 1.21, 0.48, 0.17 (p = 0.068); 7 h - 2.62, 1.00, 0.17 (p < 0.001); 12 h - 3.08, 0.65, 0.37 (p < 0.001); 24 h - 2.50, 1.20, 0.41 (p < 0.001); rescue medication requests (incidence, %): 77%, 16.7%, 13.3% (p < 0.001); mean respiratory rate (breath/min) - 15.2; 15.2 (p > 0.05); mean SpO2 (%): 96.7%; 95.7%; 96.07%. Significant adverse effects: pruritus in ITM 0.2 mg group (23% of subjects, p < 0.001).

CONCLUSIONS

Adult patients undergoing THA under spinal anaesthesia with bupivacaine and 0.2 mg morphine had superior analgesia to patients who received spinal analgesia with bupivacaine or bupivacaine and 0.1 mg morphine.

TRIAL REGISTRATION

Study ID ISRCTN37212222; 20/04/2022 (registered retrospectively).

Pericapsular Nerve Group (PENG) Block versus Supra-Inguinal Fascia Iliaca Compartment Block for Total Hip Arthroplasty: A Randomized Clinical Trial

This study compared the effects of the pericapsular nerve group (PENG) block and supra-inguinal fascia iliaca compartment block (FICB) on postoperative analgesia and quadriceps strength following total hip arthroplasty under general anesthesia. A total of 58 patients were randomized to receive either PENG block (PENG group) or supra-inguinal FICB (FICB group) following anesthetic induction. The primary outcomes were the postoperative pain scores. Patients were randomized to receive either PENG block or supra-inguinal FICB following anesthetic induction. Pain scores at rest and with movement were assessed preoperatively, at the postanesthesia care unit (only at rest), and at 6, 24, 36, and 48 h postoperatively. Opioid consumption was also assessed for 48 h postoperatively. Quadriceps strength measurements were performed preoperatively, at 6, 24, and 36 h postoperatively. In total, 54 patients completed the study: 27 in the PENG group and 27 in the FICB group. Despite lower pain scores at rest in the PENG group at postoperative 6 and 24 h, there were no significant differences in the pain scores at rest and during movement between the two groups during postoperative 48 h in the linear mixed model analysis (p = 0.079 and p = 0.323, respectively). Cumulative opioid consumption up to postoperative 48 h was also similar in the two groups (p = 0.265). The changes in quadriceps strength measurements in the operative leg and the nonoperative leg were not significantly different between the groups (p = 0.513 and p = 0.523, respectively). The PENG block may have similar analgesic efficacy to the supra-inguinal FICB. No difference was detected in the quadriceps strength between the patients receiving these two blocks.