Spinal bupivacaine in ambulatory surgery: the effect of saline dilution

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.

Postoperative urinary retention: A controlled trial of fixed-dose spinal anesthesia using bupivacaine versus ropivacaine

Background and Aims

Following spinal anesthesia (SA), patient discharge is often delayed due to postoperative urinary retention (POUR), the incidence of which varies widely. The present study of bupivacaine versus ropivacaine in equianalgesic doses was taken to explore the correlation between time to void urine and time for complete functional recovery.

Material and Methods

In this double-blinded study fifty adult patients were assigned to two groups (bupivacaine/ropivacaine) according to alternate case allocation for receiving SA for lower abdominal, perineal, and lower limb surgeries, lasting less than 2 h. Statistical analysis was conducted using an intention-to-treat approach, using Mann-Whitney test for nonparametric data. Primary outcome data could not be obtained for 14 out of the 50 patients due to perioperative bladder catheterization. No patients were lost to follow-up.

Results

Both the bupivacaine and ropivacaine groups were comparable in terms of ability to void (8.0 ± 2.3 vs. 7.0 ± 1.2 h; P > 0.05), modified Bromage scale after 4 h of SA (1.8 ± 1.3 vs. 2.6 ± 0.9 grade; P > 0.05), time to complete ambulation (6.7 ± 1.4 vs. 6.1 ± 1.0 h; P > 0.05), and time to negative Romberg test (6.1 ± 1.4 vs. 5.6 ± 0.9 h; P > 0.05), respectively. Strong positive correlations (r = 0.7-0.9) were found between time to void urine and time for complete ambulation.

Conclusions

Time to void urine and recovery of motor functions were found comparable statistically when bupivacaine and ropivacaine were used in the doses of 12.5 and 18.75 mg, respectively, for SA. However, group ropivacaine required lesser time to void and no patient developed POUR. Time to void urine was more than the time for ambulation. This may indicate a need for "selective spinal anesthesia" or adjuvant combination technique to accelerate the resolution of a block for ambulatory surgery.

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.

Comparison of two doses of hypobaric bupivacaine in unilateral spinal anesthesia for hip fracture surgery: 5 mg versus 7.5 mg

Introduction

Hip fracture is a frequent and severe disease. Its prognosis depends on the perioperative hemodynamic stability which can be preserved by the unilateral spinal anesthesia especially with low doses of local anesthetics. This study aims to compare the efficacy and hemodynamic stability of two doses of hypobaric bupivacaine (7.5 mg vs 5 mg) in unilateral spinal anesthesia.

Methods

In this prospective, randomized, double-blind study, 108 patients scheduled for hip fracture surgery under unilateral spinal anesthesia were enrolled to receive either 5 mg (group 1) or 7.5 mg (group 2) of hypobaric bupivacaine. Spinal anesthesia was performed in lateral position. Patients’ socio-demographic characteristics, hemodynamic profile, sensory and motor blocks parameters were recorded.

Results

Both groups were comparable regarding to demographic data. Two cases of failure occurred in group 1 and one case in group 2 corresponding to a comparable efficiency rates (96.29% and 98.14% respectively; p = 0.5). A higher mean onset and lower mean regression times of sensory block were significantly noted in group 1 (7.79±3.76 min vs 5.75±2.35 min, p < 0.001 and 91.29±31.55 min vs 112.77±18.77 min, p <0.001 respectively). Incidence of bilateralization (29.62% vs 87.03%, p < 0.001), incidence of hypotensive episodes (59.25% vs 92.59%, p < 0.001) and vascular loading (1481.48±411.65 ml vs 2111.11±596.10 ml, p < 0.001) were significantly higher in group 2.

Conclusion

The dosage of 5mg of hypobaric bupivacaine in unilateral spinal anesthesia is as effective as the dosage of 7.5 mg with lower bilateralization incidence and better hemodynamic stability.

[Unilateral spinal anesthesia : Literature review and recommendations]

Unilateral spinal anesthesia is a cost-effective and rapidly performed anesthetic technique. An exclusively unilateral block only affects the sensory, motor and sympathetic functions on one side of the body and offers the advantages of a spinal block without the typical adverse side effects seen with a bilateral block. The lack of hypotension, in particular, makes unilateral spinal anesthesia suitable for patients with cardiovascular risk factors e. g. aortic valve stenosis or coronary artery disease. Increasing numbers of surgical procedures are now being performed on an outpatient basis. Until now, spinal anesthesia has been considered unsuitable for this, not only because of the high incidence of intraoperative hypotension and postoperative urinary retention but also because of the prolonged postoperative stay before home discharge. This is not the case with unilateral spinal anesthesia: motor function returns rapidly, the incidence of urinary retention is extremely low, and patients are usually eligible for home discharge sooner than after bilateral spinal anesthesia or general anesthesia. The success of the technique depends on a number of factors. In addition to the local anesthetic, its concentration and dose, and the baricity of the injected solution, the shape of the spinal needle, the injection speed, the patient's position during injection, and the time the patient remains in this position after injection are equally important parameters. A number of intrathecally applied adjuvant drugs are used to give a more intense and/or longer-lasting block. For this review, we collated the published data on unilateral spinal anesthesia from journals with an impact factor greater than 1.0 and defined an optimized method for performing the technique. In order to achieve an exclusively unilateral block one should use 0.5 % hyperbaric bupivacaine injected at a rate of 0.33 ml/min or slower. During the injection and the following 20 min the patient should lie in the lateral decubitus position on the side intended for surgery with knees drawn to the chest. An injection of 5 mg (1 ml) hyperbaric bupivacaine 0.5 % provides an hour-long block to T 12, and a dose of 7.5 to 10 mg (1.5-2.0 ml) extends the block to T 6. Adding clonidine (0.5 to 1.0 µg/kg BW) to the injection prolongs the duration of the block to approximately two to three hours. During the 20-minute fixation period, the cephalad spread of the block can be influenced to a certain extent by raising or lowering the head of the table.

Comparing the Duration of Spinal Anesthesia Induced With Bupivacaine and a Bupivacaince-Lidocaine Combination in Trans-Urethral Resection of the Prostate (TURP)

Background:

Spinal anesthesia is a safe anesthetic mode for transurethral prostate resection (TUPR). There are several studies assessing the effect of bupivacaine, lonely or accompanied by other drugs, on short duration operations. However, there is controversy regarding the exact combination.

Objectives:

The aim of the study was to compare the effects of spinal anesthesia with bupivacaine and low dose lidocaine with bupivacaine alone on postoperative pain in those undergoing transurethral resection of prostate (TURP).

Materials and Methods:

This was a randomized clinical trial performed in Shiraz university of medical sciences during one year. Eighty men scheduled for TURP were randomly assigned to receive spinal anesthesia with 1.5 mL bupivacaine 0.6% and 0.6 mL Lidocaine 1% or spinal anesthesia with 1.5 mL bupivacaine 0.5% in combination with 0.6 mL normal saline. The primary endpoint was the time lag between induction of spinal anesthesia and reaching the highest spinal block level. We also recorded the duration of spinal block declining to L1 level, operation duration and the admission duration.

Results:

Both study groups were comparable regarding the baseline characteristics. We did not find any difference between the two study groups regarding the duration of anesthetic block reaching the maximum level (P = 0.433) and duration of decreasing it to L1 (P = 0.189). The course of postoperative recovery and duration of hospital admission were also comparable between the groups (P = 0.661).

Conclusions:

Lidocaine does not have additive effects on duration and quality of spinal anesthesia with bupivacaine in those undergoing TURP.

Spinal anaesthesia with hyperbaric prilocaine in day-case perianal surgery: randomised controlled trial

Background. The local anaesthetics used in day-case spinal anaesthesia should provide short recovery times. We aimed to compare hyperbaric prilocaine and bupivacaine in terms of sensory block resolution and time to home readiness in day-case spinal anaesthesia. Methods. Fifty patients undergoing perianal surgery were randomized into two groups. The bupivacaine-fentanyl group (Group B) received 7.5 mg, 0.5% hyperbaric bupivacaine + 20 μg fentanyl in total 1.9 mL. The prilocaine-fentanyl group (Group P) received 30 mg, 0.5% hyperbaric prilocaine + 20 μg fentanyl in the same volume. Results. Time to L1 block and maximum block was shorter in Group P than in Group B (Group P 4.6 ± 1.3 min versus Group B 5.9 ± 01.9 min, P = 0.017, and Group P 13.2 ± 7.5 min versus Group B 15.3 ± 6.6 min, P = 0.04). The time to L1 regression and S3 regression of the sensorial block was significantly shorter in Group P than in Group B (45.7 ± 21.9 min versus 59.7 ± 20.9 min, P = 0.024, and 133.8 ± 41.4 min versus 200.4 ± 64.8 min, P < 0.001). The mean time to home readiness was shorter for Group P than for Group B (155 ± 100.2 min versus 207.2 ± 62.7 min (P < 0.001)). Conclusion. Day-case spinal anaesthesia with hyperbaric prilocaine + fentanyl is superior to hyperbaric bupivacaine in terms of earlier sensory block resolution and home readiness and the surgical conditions are comparable for perianal surgery.

Comparison of two spinal needle types to achieve a unilateral spinal block

PURPOSE

Unilateral spinal anesthesia is beneficial in patients undergoing unilateral leg surgery. The direction and the shape of the spinal needle are thought to influence the unilateral distribution of the local anesthetic in the intrathecal space. Therefore, to study the effects of different spinal needles we compared the effects of the Whitacre and Quincke spinal needles.

METHODS

This was a prospective, randomized, double-blind study of 60 consecutive outpatients scheduled for unilateral lower-limb surgery. The patients were randomized to receive spinal anesthesia with 1.2 ml of 0.5 % plain bupivacaine using either a 27-G Whitacre or a Quincke needle. One half of the local anesthetic was injected towards the nondependent side and the other half was directed cranially. The spread of spinal anesthesia, both sensory and motor blocks, was defined as the primary endpoint and was recorded at 10, 20, and 30 min after the spinal injection, at the end of the operation, 2 h after the spinal injection, and every 30 min thereafter until there was no motor block. Secondary endpoints included patient satisfaction and adverse effects.

RESULTS

There was no difference in the spread of sensory or motor blocks between the Whitacre and the Quincke groups. However, the sensory and motor blocks on the operated and the nonoperated sides were significantly different at all testing times, as expected. There was no difference in the incidence of adverse effects or patient satisfaction scores between the Whitacre and the Quincke groups.

CONCLUSION

Unilateral spinal block for outpatient surgery can be achieved with both pencil-point (Whitacre) and Quincke needles using 6.0 mg of plain bupivacaine. Neither the spread of sensory and motor blocks nor the corresponding recovery times appeared to be different between the groups. Nor was there any difference in patient satisfaction.

Comparison of two different doses of intrathecal levobupivacaine for transurethral endoscopic surgery

OBJECTIVE

To evaluate the effects of two different spinal isobaric levobupivacaine doses on spinal anesthesia characteristics and to find the minimum effective dose for surgery in patients undergoing transurethral resection (TUR) surgery.

MATERIALS AND METHODS

Fifty male patients undergoing TUR surgery were included in the study and were randomized into two equal groups: Group LB10 (n=25): 10 mg 0.5% isobaric levobupivacaine (2 ml) and Group LB15 (n=25): 15 mg 0.75% isobaric levobupivacaine (2 ml). Spinal anesthesia was administered via a 25G Quincke spinal needle through the L3-4 intervertebral space. Sensorial block levels were evaluated using the 'pin-prick test', and motor block levels were evaluated using the 'Bromage scale'. The sensorial and motor block characteristics of patients during intraoperative and postoperative periods and recovery time from spinal anesthesia were evaluated.

RESULTS

In three cases in the Group LB10, sensorial block did not reach the T10 level. Complete motor block (Bromage=3) did not occur in eight cases in the Group LB10 and in five cases in the Group LB15. The highest sensorial dermatomal level detected was higher in Group LB15. In Group LB15, sensorial block initial time and the time of complete motor block occurrence were significantly shorter than Group LB10. Hypotension was observed in one case in Group LB15. No significant difference between groups was detected in two segments of regression times: the time to S2 regression and complete sensorial block regression time. Complete motor block regression time was significantly longer in Group LB15 than in Group LB10 (p<0.01).

CONCLUSION

Our findings showed that the minimum effective spinal isobaric levobupivacaine dose was 10 mg for TUR surgery.

Comparison of bupivacaine and 2-chloroprocaine for spinal anesthesia for outpatient surgery: a double-blind randomized trial

BACKGROUND

We have always been searching for the ideal local anesthetic for outpatient spinal anesthesia. Lidocaine has been associated with a high incidence of transient neurological symptoms, and bupivacaine produces sensory and motor blocks of long duration. Preservative-free 2-chloroprocaine (2-CP) seems to be a promising alternative, being a short-acting agent of increasing popularity in recent years. This study was designed to compare 2-CP with bupivacaine for spinal anesthesia in an elective ambulatory setting.

METHODS

A total of 106 patients were enrolled in this randomized double-blind study. Spinal anesthesia was achieved with 0.75% hyperbaric bupivacaine 7.5 mg (n = 53) or 2% preservative-free 2-CP 40 mg (n = 53). The primary endpoint for the study was the time until reaching eligibility for discharge. Secondary outcomes included the duration of the sensory and motor blocks, the length of stay in the postanesthesia care unit, the time until ambulation, and the time until micturition.

RESULTS

The average time to discharge readiness was 277 min in the 2-CP group and 353 min in the bupivacaine group, a difference of 76 min (95% confidence interval [CI]: 40 to 112 min; P < 0.001). The average time for complete regression of the sensory block was 146 min in the 2-CP group and 329 min in the bupivacaine group, a difference of 185 min (95% CI: 159 to 212 min; P < 0.001). Times to ambulation and micturition were also significantly lower in the 2-CP group.

CONCLUSION

Spinal 2-chloroprocaine provides adequate duration and depth of surgical anesthesia for short procedures with the advantages of faster block resolution and earlier hospital discharge compared with spinal bupivacaine. (ClinicalTrials.gov number, NCT00845962).

[Spinal anaesthesia in day-case surgery. Optimisation of procedures]

BACKGROUND

Since prilocaine is being increasingly used for day case surgery as a short acting local anaesthetic for spinal anaesthesia and because of its low risk for transient neurological symptoms, we compared it to bupivacaine.

PATIENTS AND METHODS

Patients (n=88) who were scheduled for lower limb surgery with spinal anaesthesia randomly received 15 mg hyperbaric bupivacaine 0.5% or 60 mg hyperbaric prilocaine 2% (administered in a sitting position). Onset time, intensity, duration of the sensomotoric block, vital parameters and time of spontaneous miction were recorded and patients were questioned on satisfaction with the anaesthesia procedure and the occurrence of adverse side-effects after 24 h.

RESULTS

Bupivacaine caused a significantly higher sensory block than prilocaine (T6 vs. T8). Both groups were similar in reaching an analgesic level of at least T12, block intensity and onset times. Median analgesic levels at T12 were maintained for 60 min with prilocaine versus 120 min with bupivacaine, regression of the motor block was 135 min versus 210 min, sensory block S1 was 240 min versus 360 min, and time for spontaneous miction was 306 min versus 405 min, respectively (differences for all comparisons were statistically significant).

CONCLUSION

Under the present study conditions, hyperbaric prilocaine 2% was superior to hyperbaric bupivacaine 0.5% due to a shorter effect profile but otherwise equivalent quality of block. However, puncture in a sitting position and positioning with elevated torso for restriction of the cranial expansion of block spread might cause an enhanced sacral block with delayed recovery of bladder function.

Bilateral vs. unilateral spinal anesthesia for outpatient knee arthroscopies

This prospective randomized study compared unilateral and bilateral spinal anesthesia with respect to intraoperative and postoperative complications, and time to discharge from hospital for knee arthroscopies in outpatients. We studied 70 ASA I patients scheduled for elective outpatient knee arthroscopy. The patients were randomly allocated into two groups to receive either 3 ml (15 mg) 0.5% hyperbaric bupivacaine (bilateral group) or 1.5 ml (7.5 mg) 0.5% hyperbaric bupivacaine (unilateral group). The duration of motor and sensory block and the time to discharge from the hospital were all recorded. Perioperative complications such as hypotension, bradycardia, nausea, vomiting, urinary retention, if present, were recorded. The patients were interviewed by telephone 7 days later, and each patient was asked about headache or backache. The duration of motor and sensory block, and the time to discharge from hospital was shorter in the unilateral group than in the bilateral group. Three patients in the bilateral group were treated for hypotension. Bradycardia occurred in two patients in the bilateral group, and three patients required temporary bladder catheterization due to delay in recovery of spontaneous urination. Nausea and vomiting occurred in three patients in bilateral group. Nine patients in the bilateral group and six patients in the unilateral group developed postspinal headache. Backache occurred in five patients in the bilateral group and in six patients in the unilateral group. Our data indicate that the use of unilateral spinal block is a suitable technique for knee arthroscopies in outpatients.

Intrathecal anesthesia

PURPOSE OF REVIEW

Development of new drugs and special techniques, as well as changes in health care organization have markedly influenced the use of spinal block and its indications. The present review overviews recent developments in local anesthetic drugs, side effects and special techniques for intrathecal anesthesia.

RECENT FINDINGS

Severe complications after spinal anesthesia are acceptably rare. The cardiovascular effects associated with sympathetic block are more frequent but may successfully be treated with volume expansion and administration of vasoactive drugs while the multimodal approach to prevention of such side effects can also reduce the incidence. Based on recent magnetic resonance imaging studies the volume of cerebrospinal fluid at the lumbosacral level is the main determinant of the effects produced by intrathecal injection of local anesthetic solutions. Unfortunately, it is not possible to estimate the volume of cerebrospinal fluid at the lumbosacral region in clinical practice, but it is clear that the total dose of local anesthetic injected into the subarachnoid space is the primary determinant of both therapeutic and unwanted effects of spinal anesthesia. There is overwhelming evidence of the potential risk for neurological dysfunction associated with spinal lidocaine. This evidence is even more relevant in outpatients, in whom lidocaine is primarily indicated. On the other hand, several studies have demonstrated the efficacy and safety of using small doses of long-acting agents, such as bupivacaine or ropivacaine, to produce a short spinal block. The addition of small doses of opioids further helps to minimize the dose of local anesthetic solution required, without affecting the recovery profile from spinal block. The extensive use of pencil-point designs for spinal needles, and the availability of needles of very small size have allowed a significant reduction in the incidence of postdural puncture headache.

SUMMARY

The changes in health care organization observed during the past few years have forced us to change the indications for and clinical uses of intrathecal anesthesia techniques in accordance with the changing needs of surgery. The development of new drugs and special techniques for spinal anesthesia will further improve the clinical use of this old but trusted technique.

Recent developments in regional anesthesia for ambulatory surgery

The use of regional anesthesia techniques is increasing in popularity because they reduce the incidence of postoperative complications, including nausea, vomiting, and pain, and decrease the recovery time and hospital stay. This article reviews the recent developments in regional anesthesia techniques and the modifications necessary to adapt them for ambulatory surgery.