The anesthetic and recovery profile of two doses (60 and 80 mg) of plain mepivacaine for ambulatory spinal anesthesia

Mepivacaine Versus Bupivacaine for Spinal Anesthesia: A Systematic Review and Meta-analysis of Random Controlled Trials

INTRODUCTION

Bupivacaine is a more widely used anesthetic than mepivacaine. However, the long-acting effects of bupivacaine often lead to slow and unpredictable return. As an intermediate-acting local anesthetic, mepivacaine can enable earlier ambulation and thus has other benefits. We performed a systematic review and meta-analysis of available randomized controlled trials (RCTs) comparing the anesthetic effects of mepivacaine and bupivacaine.

METHODS

On August 12, 2021, a search was performed in PubMed, Embase, and the Cochrane Library. Effect estimates with 95% CI were combined using a random effects model. We performed sensitivity analyses to explore sources of heterogeneity and stability of results.

RESULTS

Of the 406 papers screened, 14 population-based randomized controlled trials were included, with a total of 1007 patients. Overall, compared to bupivacaine, mepivacaine was associated with higher numbers of motor block 3 (OR, 4.05; 95% CI 1.92-8.57), shorter length of stay (SMD, - 0.77; 95% CI - 1.52 to - 0.03), faster recovery from motor block (SMD, - 1.45; 95% CI - 2.39 to - 0.51), and shorter time to return to voiding (SMD, - 1.24; 95% CI - 1.83 to - 0.64). Mepivacaine was associated with a higher incidence of transient neurologic symptoms (TNS) and transient nerve root irritation (TRI) (OR, 9.18; 95% CI 2.42-34.88). There was no statistical difference between the two anesthetics in terms of pain index on the postoperative day (SMD, 0.20; 95% CI - 0.06 to 0.46) and incidence of urinary retention (OR, 0.98; 95% CI 0.47-2.03).

CONCLUSIONS

Mepivacaine may have advantages over bupivacaine in terms of achieving motor block 3, shorter length of stay, earlier recovery from motor block, and earlier time to return to voiding, but it may have a higher incidence of TNS or TRI than bupivacaine. Therefore, mepivacaine may be used before bupivacaine in spinal anesthesia.

Time of return of neurologic function after spinal anesthesia for total knee arthroplasty: mepivacaine vs bupivacaine in a randomized controlled trial

Background

Mepivacaine as an intermediate-length spinal anesthetic for rapid recovery in total knee arthroplasty (TKA) has not been fully described. We compared spinal mepivacaine vs bupivacaine for postoperative neurologic function in patients undergoing primary TKA.

Methods

Thirty-two patients undergoing primary TKA were enrolled. Primary outcome measure was return of motor and sensory function. Secondary outcome measures included assessment of urinary function, pain via visual analog scale (VAS) scores, opioid usage, distance walked and pain with physical therapy, time to discharge readiness, and complications.

Results

Patients with mepivacaine spinal anesthetic had faster return of sensory function (164 ± 38.6 vs 212 ± 54.2 minutes, P = .015), return of motor function (153 ± 47.4 vs 200 ± 45.2 minutes, P = .025), and time to straight leg raise (148 ± 43.5 vs 194 ± 50.8 minutes, P = .023). The mepivacaine group experienced significantly fewer episodes of urinary retention and shorter time to urination (344 ± 154.4 vs 416 ± 96.3 minutes, P = .039). Patients exhibited slightly higher VAS pain scores in the postanesthesia care unit (1.0 ± 1.7 vs 2.7 ± 2.3, P = .046) with no difference in opioid consumption. There were no differences in VAS scores or opioid use on the inpatient ward. Patients achieved discharge readiness 71 minutes faster in the mepivacaine group. There was no need to convert to general anesthesia or transient nerve symptoms in either group.

Conclusions

Patients undergoing TKA with mepivacaine spinal anesthetic had a reliably more rapid neurologic recovery after TKA compared to bupivacaine.

Post-operative urinary retention: Review of literature

Postoperative urinary retention (POUR) is one of the postoperative complications which is often underestimated and often gets missed and causes lot of discomfort to the patient. POUR is essentially the inability to void despite a full bladder in the postoperative period. The reported incidence varies for the wide range of 5%-70%. Multiple factors and etiology have been reported for occurrence of POUR and these depend on the type of anaesthesia, type and duration of surgery, underlying comorbidities, and drugs used in perioperative period. Untreated POUR can lead to significant morbidities such as prolongation of the hospital stay, urinary tract infection, detrusor muscle dysfunction, delirium, cardiac arrhythmias etc. This has led to an increasing focus on early detection of POUR. This review of literature aims at understanding the normal physiology of micturition, POUR and its predisposing factors, complications, diagnosis and management with special emphasis on the role of ultrasound in POUR.

Transient Neurologic Symptoms following Spinal Anesthesia with Isobaric Mepivacaine: A Decade of Experience at Toronto Western Hospital

Background

Transient neurologic symptoms (TNSs) can be distressing for patients and providers following uneventful spinal anesthesia. Spinal mepivacaine may be less commonly associated with TNS than lidocaine; however, reported rates of TNS with intrathecal mepivacaine vary considerably.

Materials and Methods

We conducted a retrospective cohort study reviewing the internal medical records of surgical patients who underwent mepivacaine spinal anesthesia at Toronto Western Hospital over the last decade to determine the rate of TNS. We defined TNS as new onset back pain that radiated to the buttocks or legs bilaterally.

Results

We found one documented occurrence of TNS among a total of 679 mepivacaine spinal anesthetics (0.14%; CI: 0.02-1.04%) that were performed in 654 patients.

Conclusion

Our retrospective data suggest that the rate of TNS associated with mepivacaine spinal anesthesia is lower than that previously reported in the literature.

Large intrathecal volume: a cause of true failed spinal anesthesia

A 37-year-old woman scheduled for postpartum tubal ligation received two intrathecal doses of 2% hyperbaric mepivacaine (44 mg and 40 mg) and a subsequent single dose of 5% hyperbaric lidocaine (62.5 mg). Her sensory level never extended beyond S1. She subsequently underwent an uneventful general anesthetic, and had no residual sensory or motor deficits. An examination of the patient's lumbosacral magnetic resonance imaging (MRI) scan revealed an unusually large thecal volume. A large lumbosacral intrathecal volume may result in significant dilution or poor redistribution of hyperbaric local anesthetic. The final sensory level may be reduced or absent as a result. Intrathecal volume may be the most important non-modifiable factor affecting intrathecal distribution of local anesthetics; however, it cannot be easily measured or predicted. True failed spinal anesthesia should be distinguished from technical mishap, i.e., failing to introduce the anesthetic into the intrathecal space. The differential of a truly failed single-injection spinal anesthetic may include a large thecal volume, dural ectasias, cysts, and simple anatomic sacral restriction. To minimize maldistribution and neurotoxicity, the sum dose of all intrathecal local anesthetics administered for a single procedure should not significantly exceed the maximum recommended single-dose amount.