Unilateral bupivacaine spinal anesthesia for outpatient knee arthroscopy. Italian Study Group on Unilateral Spinal Anesthesia

A comparative study of unilateral vs bilateral spinal anaesthesia using hyperbaric bupivacaine with buprenorphine in unilateral inguinal hernia surgery

Unilateral spinal anaesthesia can be used for inguinal hernia surgery. The advantage is that it provides a stronger block on the side of surgery and accelerated recovery of the nerve block, with better maintenance of cardiovascular stability. Hence it can be a valuable technique for high-risk patients. The aim: This randomized controlled trial was designed to evaluate the onset and duration of Sensory and motor block in both unilateral and bilateral spinal anaesthesia and the adverse effects of buprenorphine given intrathecally with 0.5 % bupivacaine for Spinal anaesthesia in patients scheduled for unilateral inguinal hernia surgery. Materials and methods: it is a сomparative two group randomized clinical study with 60 patients with 30 patients in Group U (UNILATERAL) and 30 patients in Group B (BILATERAL) is undertaken to study the changes in haemodynamics and side effects. Whereas, within the group (for the unilateral group) comparison of the time taken to reach L1, T12, T10 and the Bromage time between the surgical side and non-surgical side sides of surgery was done. Results: T10 -T12 spinal anaesthesia was achieved in both groups; the average time to anaesthetic onset in the unilateral group was 5.27±1.2 min, and in the bilateral, it was 5.90±1.02 min (p-value=0.32). Sensory and motor block lasted longer in the bilateral group when compared to the unilateral group; the incidence of side effects was limited to the occurrence of hypotension and bradycardia in the unilateral group than in the bilateral group. The success rate of unilateral spinal anaesthesia in our study was 100 %. Conclusion: Because of haemodynamic stability and faster recovery characteristics of unilateral spinal block, it can be used as a suitable technique in patients with a limited cardiovascular reserve and for outpatient anaesthesia.

Dose Selection of Ropivacaine for Spinal Anesthesia in Elderly Patients with Hip Fracture: An Up-Down Sequential Allocation Study

Objective

The dose selection of ropivacaine for spinal anesthesia in clinical work mainly depends on the experience of the anesthesiologist. In this study, a prospective and modified up-down sequential allocation design was used to provide the optimal dose selection of ropivacaine for spinal anesthesia.

Patients and methods

This study was divided into two stages, and a total of 164 elderly patients with elective hip fractures were included. In stage I, the dose of ropivacaine was selected using the up-down sequential method of height correction, and the 50% effective dose (ED50) and 95% effective dose (ED95) were obtained. A nomogram for predicting satisfactory anesthesia and a formula for predicting the optimal dose was also given in this stage. In stage II, the dose of ropivacaine was calculated by using the optimal dose prediction formula, so as to evaluate the efficacy and safety of the model.

Results

The ED50 and ED95 of the stage I were 7.036 mg (95%CI 6.549–7.585 mg) and 8.709 mg (95%CI 7.902–14.275 mg), respectively. And provided a nomogram predicting satisfactory anesthesia with a C-index of 0.847 (95%CI 0.774–0.92). The optimal dose prediction formula of ropivacaine was calculated, including variables for age, gender, height, and weight. This formula was found to be 90% efficient. It is worth mentioning that the incidence of direct transfer to the ward in the two stages was as high as 86.84% and 93.33%, respectively, and no patients were transferred to the ICU in stage II.

Conclusion

The ED50 and ED95 of ropivacaine were 7.036 mg and 8.709 mg, respectively, and the nomograms are sufficiently accurate to predict satisfactory anesthesia. Beyond that, the dose prediction equation provided in this study has high efficacy and safety, and can guide the dose selection of spinal anesthesia in elderly patients with hip fracture in clinical practice.

Clinical trials registration

ChiCTR2100046982

Spinal anaesthesia with chloroprocaine 1% versus total intravenous anaesthesia for outpatient knee arthroscopy: A randomised controlled trial

BACKGROUND

Both general and spinal anaesthesia with short-acting local anaesthetics are suitable and reliable for knee arthroscopy as an ambulatory procedure. Chloroprocaine (CP) 1% seems to be the ideal spinal local anaesthetic for this indication.

OBJECTIVE

The aim of this study was to compare spinal anaesthesia using CP 1% with general for outpatient knee arthroscopy with regard to procedure times, occurrence of pain, patient satisfaction and recovery, and also costs.

DESIGN

A randomised controlled single-centre trial.

SETTING

University Medical Centre Mannheim, Department of Anaesthesiology and Surgical Intensive Care Medicine, Mannheim, Germany. April 2014 to August 2015.

PATIENTS

A total of 50 patients (women/men, 18 to 80 years old, ASA I to III) undergoing outpatient knee arthroscopy were included. A contra-indication to an allocated anaesthetic technique or an allergy to medication required in the protocol led to exclusion.

INTERVENTIONS

Either general anaesthesia with sufentanil, propofol and a laryngeal mask for airway-management or spinal with 40-mg CP 1% were used. We noted procedure times, patient satisfaction/recovery and conducted a 7-day follow-up.

MAIN OUTOMES

Primary outcome was duration of stay in the day-surgery centre. Secondary outcomes were first occurrence of pain, patient satisfaction, quality of recovery and adverse effects. In addition, we analysed treatment costs.

RESULTS

Spinal had faster recovery than general anaesthesia with patients reaching discharge criteria significantly earlier [117 min (66 to 167) versus 142 min (82 to 228), P = 0.0047]. Pain occurred significantly earlier in the general anaesthesia group (P = 0.0072). Costs were less with spinal anaesthesia (cost ratio spinal: general 0.57). Patients felt significantly more uncomfortable after general anaesthesia (P = 0.0096).

CONCLUSION

Spinal anaesthesia with 40-mg CP 1% leads to a significantly earlier discharge and is cheaper compared with general.

TRIAL REGISTRATION

German Clinical Trials Register, www.drks.de, identifier: DRKS00005989.

Caudal and intravenous dexmedetomidine similarly prolong the duration of caudal analgesia in children: A randomized controlled trial

BACKGROUND

Dexmedetomidine can prolong the duration of action of a local anesthetic agent, but the route of administration that is the most beneficial remains unclear. The purpose of this study was to compare the clinical effectiveness of caudal or intravenous dexmedetomidine administration on postoperative analgesia in children undergoing inguinal hernia repair given caudal levobupivacaine.

METHODS

This was a prospective, randomized, double-blinded, placebo-controlled trial. Ninety ASA I subjects, aged 2-5 year, undergoing unilateral inguinal hernia repair were enrolled. The children were randomized in a double-blind fashion to three groups. The L-Dcau group received 1 mL/kg of caudal 0.25% levobupivacaine plus 1 μg/kg dexmedetomidine and IV 20 mL saline. The L-Div group received 1 mL/kg of caudal 0.25% levobupivacaine and IV 1 μg/kg dexmedetomidine in 20 mL saline. The L group received 1 mL/kg of caudal 0.25% levobupivacaine and IV 20 mL saline. The primary outcome was the duration of analgesia, which was defined as the time from the caudal block to a Postoperative Pain Scale (CHIPPS) score ≥4. Secondary outcomes were the number of patients requiring rescue analgesia, pain intensity, the incidence of emergence agitation, intraoperative hemodynamic variations, residual motor block, and adverse effects.

RESULTS

The median duration of analgesia in the L-Dcau group was 14.2 hour compared to 6 hour in the L group with a median difference of 8.5 hour [95% CI (6.5, 10.5), P < 0.001]. The median duration of analgesia in the L-Div group was 12.4 hour compared to 6 hour in the L group with a median difference of 6.4 hour [95% CI (4, 8.5), P < 0.001]. Fewer patients in the L-Dcau and L-Div groups required rescue analgesia in the first 24 hour postoperatively compared to the L group, although there was no significant difference between the L-Dcau and L-Div groups for these outcomes. Both dexmedetomidine routes reduced the pain and the incidence of emergence agitation. No bradycardia, hypotension, or motor block was observed in any of the three groups.

CONCLUSION

Caudal and IV dexmedetomidine similarly prolong the duration of analgesia produced by caudal levobupivacaine.

Effect of spinal flexion and extension in the lateral decubitus position on the unilaterality of spinal anesthesia using hyperbaric bupivacaine

Background and Aims:

Many unilateral lower limb orthopedic surgeries are conducted under unilateral spinal anesthesia with full flexion of spine and immediate extension after local anesthetic administration into the subarachnoid space. Studies have shown that extension of the spine in lateral decubitous position makes cauda equina to sink to the dependent side due to gravity. Continuous flexion of the spine causes sunken cauda equina to be suspended in the middle of the subarachnoid space increasing the possibility of unilateralization of the block. Hence, this study was carried out to assess the effect of flexion and extension in lateral decubitus position in unilateral spinal anesthesia.

Material and Methods:

Sixty patients posted for elective unilateral lower limb below knee orthopedic surgeries were randomly allocated into two groups—group F (flexion of spine) and group E (extension of spine). Using a 25-gauge Quincke spinal needle, 8 mg of 0.5% hyperbaric bupivacaine was injected over a period of 80 s at L3–L4 interspace. Patients were kept in flexion or extension according to the group they belong to after drug administration. After 15 min of lateral position in either group, patients were turned to supine position. Sensory blockade was assessed by loss of pinprick sensation and motor blockade by modified Bromage scale.

Results:

Strict unilateral sensory block at 15^th min was in 18 patients in flexion group compared with 11 patients in extension group which is statistically significant (p=0.03). At 60^th min, there was no significant sensory unilaterality between the groups (p=0.06). A strict unilateral motor blockade at 15^th min was also in 18 patients in group F and 11 patients in group E which was also statistically significant (p=0.04). At 60^th min, seven patients in group F and three patients in group E had strict unilateral motor blockade which was also statistically significant (p=0.03). The maximum sensory level on the nondependent side was T10 in group F and T8 in group E, whereas it was T6 in both the groups on the dependent side. There was no difference in the two-segment regression of the sensory block, duration of sensory and motor blockade, the maximum level of the block, and hemodynamic status between the groups.

Conclusion:

Maintaining flexion of the spinal column for 15 min increases the likelihood of unilateral spinal block compared with extension of the spinal column during lateral decubitus positioning.

Comparison of Efficacy and Safety of Unilateral Spinal Anaesthesia with Sequential Combined Spinal Epidural Anaesthesia for Lower Limb Orthopaedic Surgery

INTRODUCTION

Orthopaedic anaesthesia plan requires customi-zation as per patient's need for safe outcome. Sequential Combined Spinal Epidural Anaesthesia (Sequential CSEA) and Unilateral Single Shot Spinal anaesthesia (Unilateral SA), both have advantages over conventional spinal anaesthesia that they provide longer lasting block with less hypotension.

AIM

To compare safety and efficacy of unilateral spinal anaesthesia with sequential combined spinal epidural anaesthesia for lower limb orthopaedic surgery .

MATERIALS AND METHODS

This prospective randomized study was conducted on sixty ASA I-III patients aged 18- 65 years undergoing lower limb orthopaedic surgeries of approximately two hours duration. Sequential CSE group received spinal with 5 mg of 0.5 hyperbaric bupivacaine followed by incremental epidural top up of 2 cc of 0.5% isobaric bupivacaine to achieve and maintain T10 level. In unilateral SA group, unilateral spinal anaesthesia was given with 10 mg of 0.5% hyperbaric bupivacaine. Haemodynamic parameter, anaesthesia readiness time and block characteristics were recorded and results were analysed using unpaired Student's t-test.

RESULTS

There was no failure of block, surgical anaesthesia with T10 sensory level and bromage score three motor block was achieved by all patients in both groups. Anaesthesia readiness time was less in unilateral SA (p<0.001) Incidences of hypotension (p-value 0.0059) and mean ephedrine dose were significantly less in sequential CSEA. Five patients of unilateral SA required supplementation with general anaesthesia.

CONCLUSION

Thus, our study concludes that unilateral SA is a cost-effective and rapidly performed anaesthetic technique. Unilateral SA with 10 mg bupivacaine and sequential CSEA with 5 mg spinal and incremental epidural top up, both provide good quality sensory and motor block for lower limb orthopaedic surgery but sequential CSEA provides significantly more stable haemodynamics with feasibility to prolong block. Thus sequential CSEA should be preferred over unilateral SA in high risk patients especially for major lower limb orthopaedic surgeries.

[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.

Comparison of Intraoperative and Postoperative Effects of Lateral Epidural and Midline Epidural Anaesthesia in Patients Undergoing Unilateral Lower Extremity Operation

OBJECTIVE

We aimed to compare lateral and midline epidural anaesthesia using a levobupivacaine-fentanyl combination in patients undergoing unilateral lower extremity operation for anaesthetic effects and postoperative complications.

METHODS

The study included 40 American Society of Anesthesiologists (ASA) I-II group patients. At the L4-5 space, an epidural catheter was placed in patients in Group 1 by directing the tip of the needle at a 45-degree angle to the operation side and in Group 2 with the needle tip in the cephalad direction. Patients in both groups were administered a combination of 10 mL 0.5% levobupivacaine and 50 μg fentanyl via the epidural catheter. Sensorial and motor block levels during the perioperative and postoperative periods and postoperative complications were recorded.

RESULTS

The maximum level of sensory block on the operated side was found to be at the T10 (T8-T10) level in both groups, while the level of sensory block on the non-operated side was at the L2 (L3-T10) level in Group 1, and at the T10 (T8-T10) level in Group 2 (p=0.000). The motor block was more intense on the non-operated side in Group 2 than in Group 1. The postoperative motor block ended earlier in Group 1. The incidence of complication development was similar between the groups.

CONCLUSION

With a shorter lasting and lower level sensorial and motor block, lateral epidural anaesthesia may be a more advantageous method than midline epidural anaesthesia.

The influence of spinal flexion in the lateral decubitus position on the unilaterality of spinal anesthesia

BACKGROUND

For unilateral spinal block, local anesthetics should affect the spinal nerves of 1 side. With full flexion of the spine, the sunken cauda equina becomes tightened and is suspended in the middle of the subarachnoid space. We performed this study to assess whether spinal flexion facilitates unilateral spinal anesthesia.

METHODS

Hyperbaric bupivacaine (8 mg) was administered at the L3-4 interspace through a 25-gauge Quincke needle at a rate of 0.02 mL/s. Patients were randomly allocated to group F (with full spinal flexion) or group N (the hips and back straightened). After maintaining the lateral position for 15 minutes with or without spinal flexion, patients were gently returned to the supine position. Spinal blockade was assessed by loss of pinprick sensation and the modified Bromage motor scale.

RESULTS

While the lateral position was maintained, sensory block was noted on the nondependent side in 14 of 16 patients in group N (87.5%) but only in 1 of 16 patients in group F (6.3%) (P < 0.001). The median level of sensory block in group N was L5 on the nondependent side just before turning to the supine position. When patients were returned to the supine position, sensory blockade on the nondependent side was noted in all group N patients (100%) and 15 group F patients (93.7%). The sensory level on the nondependent side between group N and group F were similar after turning supine.

CONCLUSIONS

Strict unilateral sensory block was not achieved even after lateral decubitus positioning with spinal flexion, when 8 mg hyperbaric bupivacaine was administered manually at a conventionally slow rate through a beveled spinal needle. However, maintaining flexion of the spinal column during lateral decubitus positioning altered the initial onset of sensory block with respect to laterality.

Hypobaric spinal anesthesia with ropivacaine plus sufentanil for traumatic femoral neck surgery in the elderly: a dose-response study

BACKGROUND

In this randomized, prospective trial, we sought to determine the effective dose of hypobaric ropivacaine with sufentanil providing 95% success (ED95) in spinal anesthesia for traumatic femoral neck surgery in the elderly.

METHODS

Sixty-eight elderly patients with unilateral hip fracture randomly received 6, 8, 10, or 12 mg spinal hypobaric ropivacaine combined with 5 µg sufentanil. Patients remained in a lateral position for 15 minutes after spinal injection. The dose was considered successful if a unilateral sensory block >T12 was achieved, and there was no need for additional analgesia or conversion to general anesthesia. The ED95 was determined using logit analysis. The incidence of severe and very severe hypotension (systolic blood pressure decrease by >30% and >40% baseline, respectively) and the use of remifentanil were compared among groups using χ(2) test for trend.

RESULTS

Three patients were excluded because of failure to reach the subarachnoid space. No differences in baseline demographic data were observed among groups. The ED95 for hypobaric ropivacaine was determined to be 9 mg (95% confidence interval, 8-14). Increasing doses of ropivacaine (6, 8, 10, and 12 mg) demonstrated a positive trend with respect to incidence of hypotension (53%, 47%, 87%, and 81%, P = 0.0004) and a negative trend with respect to the use of remifentanil (41%, 12%, 0%, and 0%, P = 0.0004). A significant difference in the level of sensory block (P < 0.0001) was observed among operative and nonoperative sides but not among ropivacaine dosing groups (P = 0.16). No difference in motor blockade, incidence of very severe hypotension, total dose of ephedrine, duration of surgery, patient satisfaction, operating conditions, or surgeon satisfaction scores was observed among groups. No cases of bradycardia were observed. No patient had a preoperative sensory level <T12 after 15 minutes in the lateral decubitus position, and no cases were converted to general anesthesia. There was no difference in undesirable outcomes or postoperative troponin values among groups.

CONCLUSIONS

The effective dose of hypobaric ropivacaine combined with sufentanil 5 µg providing 95% success in spinal anesthesia for traumatic femoral neck surgery in the elderly is ED95 = 9 mg (95% confidence interval, 8-14). Using doses exceeding the ED95 may increase the incidence of hypotension. If doses less than the ED95 are chosen, the use of additional analgesia may be necessary.

Low-dose spinal bupivacaine for total knee arthroplasty facilitates recovery room discharge: a randomized controlled trial

PURPOSE

Regional anesthesia is the preferred technique for total knee arthroplasty to provide a bridge for early postoperative analgesia, reduce opioid consumption, and improve mobility and rehabilitation. Multiple patient and process factors must be weighed when choosing the appropriate technique to reduce morbidity and facilitate discharge. We hypothesized that a low-dose of intrathecal bupivicaine combined with regional block would facilitate discharge from the postanesthesia care unit (PACU) and reduce postoperative morbidity.

METHODS

Patients undergoing total knee arthroplasty under spinal anesthesia received either 5 mg (low-dose group) or 10 mg (standard-dose group) isobaric bupivacaine in a double-blind randomized controlled trial. The primary outcome measure was time to achieve eligibility for PACU discharge. Secondary outcome measures included time to recovery of S2 dermatome sensation, time to voiding, rate of bladder catheterization, and time required for nursing intervention in the PACU and after discharge to the surgical ward.

RESULTS

Forty-five of the 49 recruited patients completed the study. Patients receiving low-dose spinal anesthesia were eligible for PACU discharge earlier than those receiving the standard dose (P = 0.0036). Patients receiving the standard dose had significantly delayed recovery of S2 dermatome sensation (P = 0.0035). There was no difference between groups in the amount of time required for nursing intervention in the PACU, but patients receiving low-dose spinal anesthesia required more time for nursing intervention within the first four hours of their arrival on the ward (P = 0.009). None of the patients required intraoperative analgesic supplementation.

CONCLUSIONS

In patients undergoing total knee arthroplasty, low-dose intrathecal bupivacaine (5 mg) combined with regional block is associated with a reduced time to achieve eligibility for discharge from the PACU.

Ropivacaine for unilateral spinal anesthesia; hyperbaric or hypobaric?

BACKGROUND AND OBJECTIVES

The aim of this study was to compare the unilaterality of subarachnoid block achieved with hyperbaric and hypobaric ropivacaine.

METHODS

The prospective, randomized trial was conducted in an orthopedics surgical suite. In all, 60 ASA I-III patients scheduled for elective total knee arthroplasty were included in the study. Group Hypo (n=30) received 11.25mg of ropivacaine (7.5mg.mL(-1)) + 2mL of distilled water (density at room temperature was 0.997) and group Hyper (n=30) received 11.25mg of ropivacaine (7.5mg.mL(-1)) + 2mL (5mg.mL(-1)) of dextrose (density at room temperature was 1,015). Patients in the hyperbaric group were positioned with the operated side down and in the 15° Fowler position, versus those in the hypobaric group with the operated side facing up and in the 15° Trendelenburg position. Combined spinal epidural anesthesia was performed midline at the L(3-4) lumbar interspace. Hemodynamic and spinal block parameters, regression time, success of unilateral spinal anesthesia, patient comfort, surgical comfort, surgeon comfort, first analgesic requirement time, and adverse effects were assessed.

RESULTS

Time to reach the T10 dermatome level on the operated side was shorter in group Hyper (612.00±163.29s) than in group Hypo (763.63±208.35s) (p<0.05). Time to 2-segment regression of the sensory block level on both the operated and non-operated sides was shorter in group Hypo than in group Hyper.

CONCLUSION

Both hyperbaric and hypobaric ropivacaine (11.25mg) provided adequate and dependable anesthesia for total knee replacement surgery, with a high level of patient and surgeon comfort. Hypobaric local anesthetic solutions provide a high level of unilateral anesthesia, with rapid recovery of both sensory and motor block, and therefore may be preferable in outpatient settings.

Neuraxial anesthesia and bladder dysfunction in the perioperative period: a systematic review

PURPOSE

Urinary retention requiring catheterization carries the risk of infection. Neuraxial anesthesia causes transient impairment of bladder function ranging from delayed initiation of micturition to frank urinary retention. We undertook a review of the literature to determine the elements of neuraxial anesthesia and analgesia that prolong bladder dysfunction and increase the incidence of urinary retention.

METHODS

We performed a systematic search of the PubMed, MEDLINE, and EMBASE databases (from January 1980 to January 2011) to identify studies where neuraxial anesthesia and/or analgesia were employed and at least one of the following outcomes was reported: urinary retention, time to micturition, or post void residual. We included randomized controlled trials and observational studies published in the English language and we excluded case reports. The randomized trials were graded according to the Jadad score.

PRINCIPAL FINDINGS

Our search yielded 94 studies, and in 16 of these studies, the authors reported time to micturition after intrathecal anesthesia of varying local anesthetics and doses. Intrathecal injections were performed in 41 of these studies, epidural anesthesia/analgesia was used in 39 studies, and five studies involved both the intrathecal and epidural routes. Meta-analysis was not possible because of the heterogeneity of interventions and reported outcomes. The duration of detrusor dysfunction after intrathecal anesthesia is correlated with local anesthetic dose and potency. The incidence of urinary retention displays a similar trend and is further increased by the presence of neuraxial opioids, particularly long-acting variants. Urinary tract infection secondary to catheterization occurred rarely.

CONCLUSIONS

Neuraxial anesthesia/analgesia results in transient detrusor dysfunction. The duration of dysfunction depends on the potency and dose of medication used; however, it does not appear to result in significant morbidity.

Perioperative care for the older outpatient undergoing ambulatory surgery

As the number of ambulatory surgery procedures continues to grow in an aging global society, the implementation of evidence-based perioperative care programs for the elderly will assume increased importance. Given the recent advances in anesthesia, surgery, and monitoring technology, the ambulatory setting offers potential advantages for elderly patients undergoing elective surgery. In this review article we summarize the physiologic and pharmacologic effects of aging and their influence on anesthetic drugs, the important considerations in the preoperative evaluation of elderly outpatients with coexisting diseases, the advantages and disadvantages of different anesthetic techniques on a procedural-specific basis, and offer recommendations regarding the management of common postoperative side effects (including delirium and cognitive dysfunction, fatigue, dizziness, pain, and gastrointestinal dysfunction) after ambulatory surgery. We conclude with a discussion of future challenges related to the growth of ambulatory surgery practice in this segment of our surgical population. When information specifically for the elderly population was not available in the peer-reviewed literature, we drew from relevant information in other ambulatory surgery populations.

Economics and practice management issues associated with acute pain management

The use of regional anesthesia (RA) improves cost benefit (hospital-centered) and cost utility (patient-centered) over general anesthesia with volatile agents (GAVA), based upon research in outpatient populations. To make the cost savings a reality, the authors recommend: (1) avoidance of GAVA or at least volatile agents, (2) adopting published postanesthesia care unit (PACU)-bypass criteria conducive to RA, (3) maximizing PACU-bypass rates, and (4) utilizing a block induction area. Inpatient-based acute pain services are not uniform, which makes cost analyses and comparison between practices unreliable. Additional review and commentary address surgical site infections, cancer recurrence, blood transfusions, and chronic postsurgical pain.

Characteristics of unilateral spinal anesthesia at different speeds of intrathecal injection

PURPOSE

Unilateral spinal anesthesia is performed to provide restriction of sympathetic and motor block. The purpose of this study is to compare the effect of different speeds of intrathecal injection on unilateral spinal anesthesia.

METHODS

The patient cohort comprised 66 patients who were placed in the lateral position with the side to be operated on dependent. After dural puncture, the needle aperture was turned towards the dependent side, and hyperbaric 0.5% bupivacaine was injected at a rate of 1 ml/min in Group Slow patients (Group S, n = 33) or 0.5 ml/min in Group Extra Slow patients (Group ES, n = 33). The lateral position was maintained for 15 min. Skin temperature, loss of pinprick sensation, and degree of motor block were recorded.

RESULTS

There were significant differences in the characteristics of the non-operative side between the groups when on the block. Sensorial block was unilateral in 25 (75.8%) patients in Group S and in 29 patients in Group ES (87.9%) 15 min post-injection. At the end of the operation (approximately 50 min after spinal anesthesia), strictly unilateral anesthesia was present in 31 patients in Group ES (93.9%) and in 22 patients in Group S (66.6%) (p < 0.05). Unilateral sensory and motor block were observed in both groups, and the incidence of strict unilateral block was significantly higher in group ES patients.

CONCLUSIONS

The result of the study show that the extra-slow injection of hyperbaric bupivacaine provided strictly unilateral sensorial and sympathetic block in 93.9 and 87.9% of the patients, respectively, and that a slow injection of low doses of hyperbaric 0.5% bupivacaine 1 ml was sufficient to provide unilateral spinal anesthesia.

A comparison of low dose hyperbaric levobupivacaine and hypobaric levobupivacaine in unilateral spinal anaesthesia

The aim of this study was to compare the clinical effects and characteristics of hyperbaric and hypobaric levobupivacaine for unilateral spinal anaesthesia. Sixty patients were randomly allocated into two groups to receive either 7.5 mg (1.5 ml) hyperbaric levobupivacaine 0.5% or 7.5 mg (4 ml) hypobaric levobupivacaine 0.1875% for elective arthroscopic surgery of the knee under spinal anaesthesia. The level and duration of sensory block, intensity and duration of motor block were recorded. Unilateral sensory block was observed in 27 patients (90%) in the hyperbaric group and 24 patients (80%) in the hypobaric group in the lateral position. After 15 minutes, patients were turned to supine to redistribute the spinal block toward the non-operative side, but spinal anaesthesia was still unilateral in 18 patients (60%) in the hyperbaric group and 10 patients (33%) in the hypobaric group (P = 0.038). Time to readiness for home discharge and complete recovery of sensory block were similar in both groups. In the hyperbaric group, the motor block scores were higher on the operative side during first 10 minutes than they were in the hypobaric group (P < 0.002). Motor block regression was faster in the hyperbaric group (P = 0.01). Hyperbaric and hypobaric levobupivacaine both provided satisfactory unilateral spinal anaesthesia with good haemodynamic stability for arthroscopic surgery, but with more frequent unilateral spinal anaesthesia in the hyperbaric group.

Unilateral paravertebral block: an alternative to conventional spinal anaesthesia for inguinal hernia repair

BACKGROUND

Inguinal herniorrhaphy can be successfully performed using general, regional or local anaesthesia. Paravertebral block (PVB) has been used for unilateral procedures such as thoracotomy, breast surgery, chest wall trauma, hernia repair or renal surgery.

METHODS

We compared unilateral lumbar PVB with conventional spinal anaesthesia (SA) in 60 consenting ASA I and II males aged 18-65 years, scheduled for unilateral inguinal hernia repair. Patients were randomly assigned into two groups, P (n=30) or S (n=30) to receive either PVB or SA, respectively. Two patients (7%) in group P had to be converted to general anaesthesia due to block failure. During surgery, patients of both groups received intravenous infusion of propofol titrated to light sedation.

RESULTS

The time to first post-operative analgesic requirement (primary outcome measure) as 342 +/- 73 min in group P and 222 +/- 22 min in group S (P<0.0001). Time to ambulation was 234 +/- 111 min in group P and 361 +/- 32 min in group S (P<0.0001). Urinary retention requiring catheterization were found in zero (0%) patients in group P compared with five (16%) in group S (P=0.024).

CONCLUSION

It can be concluded that unilateral PVB is more efficacious than conventional SA in terms of prolonging post-operative analgesia and reducing morbidities in patients undergoing elective unilateral inguinal hernia repair.

Optimal dose of hyperbaric bupivacaine 0.5% for unilateral spinal anesthesia during diagnostic knee arthroscopy

Objective

To determine the dose of hyperbaric bupivacaine 0.5% required for unilateral spinal anesthesia during diagnostic knee arthroscopy.

Patients and methods

This prospective, randomized, clinical study was performed in 80 patients who were assigned to four groups to receive different doses of intrathecal hyperbaric bupivacaine (5 mg, 7.5 mg, 10 mg and 12.5 mg in Groups 1, 2, 3, and 4 respectively). Onset of sensory and motor block, hemodynamic changes, regression of motor block, and incidence of complications were recorded.

Results

Unilateral sensory block was reported in 90% and 85% of patients in Group 1 and Group 2, respectively, but not in any patient in Group 3 and Group 4. Unilateral motor block (modified Bromage scale 0) was reported in 95% of patients in Group 1, 90% in Group 2, and only 5% in Group 3, while no patient in Group 4 showed unilateral motor block. The time required for regression of motor block (Bromage scale 0) was prolonged with higher doses. The incidence of nausea, vomiting, and urine retention was similar in the study groups.

Conclusion

Unilateral sensory and motor block can be achieved with doses of 5 mg and 7.5 mg hyperbaric bupivacaine 0.5% with a stable hemodynamic state. However, 7.5 mg of hyperbaric bupivacaine 0.5% was the dose required for adequate unilateral spinal anesthesia.

Spinal mepivacaine with fentanyl for outpatient knee arthroscopy surgery: a randomized controlled trial

BACKGROUND

The foremost limitation of local anesthetic solutions for spinal anesthesia in the outpatient setting is prolonged motor blockade and delayed ambulation. The purpose of this study was to determine if the addition of intrathecal fentanyl to low-dose spinal mepivacaine provides adequate anesthesia with shorter duration of functional motor blockade for ambulatory knee surgery compared with spinal mepivacaine alone.

METHODS

Following institutional review board approval and informed consent, 34 patients undergoing unilateral knee arthroscopy were enrolled in this study. The patients were randomly assigned to receive either 30 mg of isobaric mepivacaine 1.5% plus fentanyl 10 microg (M + F group) or 45 mg of isobaric mepivacaine 1.5% alone (M group) intrathecally. Postoperatively, the times to achieve sensory block regression to the S1 dermatome and to attain functional motor block recovery enabling ambulation were recorded. All assessments were blinded.

RESULTS

The time to completion of Phase I recovery was shorter in the M + F group (104.6 +/- 28.4 min) than in the M group (129.1 +/- 30.4 min; P = 0.023). Regression of sensory blockade to S1 was earlier in the M + F group (118.4 +/- 53.5 min) than in the M group (169.7 +/- 38.9 min; P = 0.003). Patients in the M + F group (176.4 +/- 40.3 min) were able to ambulate significantly earlier than those in the M group (205.6 +/- 31.4 min; P = 0.025). No cases of transient or persistent neurological dysfunction were noted.

CONCLUSIONS

When compared with 45 mg isobaric mepivacaine 1.5%, an intrathecal dose of 30 mg isobaric mepivacaine 1.5% plus 10 microg fentanyl produces reliable anesthesia, hastens block regression, shortens stay in Phase I recovery, and enables earlier ambulation for patients undergoing unilateral knee arthroscopy (Registration no. NCT00803725).

Unilateral anesthesia does not affect the incidence of urinary retention after low-dose spinal anesthesia for knee surgery

We evaluated whether unilateral low-dose spinal anesthesia may reduce the likelihood of postoperative urinary retention. Forty patients scheduled for knee arthroscopy randomly received bilateral (n = 20) or unilateral (n = 20) spinal anesthesia with 6-mg hyperbaric bupivacaine 0.5%. The incidence of urinary retention (>500 mL) assessed with an ultrasound device (Bladderscan) and subsequent temporary catherization was 7/20 patients in the bilateral versus 6/20 in the unilateral group (not significant). We concluded that unilateral low-dose spinal anesthesia does not further decrease the likelihood of urinary retention. Our results demonstrate the value and necessity of monitoring bladder volume postoperatively.

Systematic review of spinal anaesthesia using bupivacaine for ambulatory knee arthroscopy

The use of lidocaine in spinal anaesthesia is associated with transient neurological syndrome (TNS). Bupivacaine has a lower incidence of TNS as an alternative but it may have a prolonged action. This study systematically reviews the literature about the recovery profile of patients undergoing spinal anaesthesia, using bupivacaine for arthroscopic knee surgery. We identified 17 eligible randomized clinical trials (RCTs) (1268 patients). All the articles in this review, except one, used hyperbaric bupivacaine. Five trials compared different doses of bupivacaine (range 3-15 mg). Large doses of bupivacaine (10 and 15 mg) were associated with delayed recovery, and supine positioning was associated with a high incidence of failure. With unilateral positioning, a dose as low as 4-5 mg seems to be sufficient. Five trials comparing bupivacaine or levobupivacaine with ropivacaine showed no significant difference in the time to home discharge. When bupivacaine was combined with fentanyl in two trials, marginal delay in recovery was found [time to discharge (min); weighted mean difference (WMD) 14.1, 95% CI 11.9-40.1] and increased nausea and pruritus but had reduced postoperative pain. Unilateral and bilateral spinal anaesthesia were assessed in two trials, and the latter group was associated with early recovery and discharge [time to discharge (min); WMD -41.6, 95% CI -63.6 to -19.6). The results of our systematic review suggest that 4-5 mg of hyperbaric bupivacaine can effectively produce spinal anaesthesia for knee arthroscopy with unilateral positioning. Ropivacaine or the addition of adjuvants did not improve the recovery time. There is a need for tighter RCTs with more consistent endpoints.

Midazolam dose for loss of response to verbal stimulation during the unilateral or bilateral spinal anesthesia

BACKGROUND

We have conducted this study to investigate whether unilateral or bilateral spinal anesthesia with bupivacaine induces different sensitivity to intravenous (i.v.) midazolam for sedation.

METHODS

Forty-two patients undergoing various elective unilateral lower extremity surgeries were allocated into two groups: (1) unilateral spinal anesthesia group (Group US, n=21; heavy bupivacaine 5 mg/ml, 9 mg) and (2) bilateral spinal anesthesia group (Group BS, n=21; heavy bupivacaine 5 mg/ml, 9 mg). One milligram of midazolam was injected i.v. at 30-s intervals until the patients did not respond to the hand grasp test beginning 15 min after spinal anesthesia. The concentration of plasma bupivacaine was evaluated every 15 min for the first 75 min after the start of the spinal anesthesia, and the bispectral index was monitored continuously.

RESULTS

The mean venous plasma concentration of bupivacaine was not significantly different between Group US and BS. The dose of midazolam required to abolish responses to verbal commands was significantly lower in Group BS (mean 5.9+/-1.2 mg) vs. Group US (mean 9.0+/-1.4 mg).

CONCLUSIONS

A higher dosage of midazolam is required for loss of response to verbal stimulation during unilateral spinal anesthesia than during bilateral spinal anesthesia.

Hypotension induced by lateral decubitus or supine spinal anaesthesia in elderly with low ejection fraction undergone hip surgery

OBJECTIVE

The aim of the study was to assess the effect of low ejection fraction (EF) on hypotension during lateral or supine position of spinal anaesthesia in patients older than 75 years old.

METHODS

We analyzed 41 patients who had undergone hip surgery between August 2000 and October 2001 in the Aydin SSK State Hospital retrospectively. Patients older than 75 years of age and an EF less than 50% were selected and spinal anaesthesia was performed with hyperbaric bupivacaine 0.5%, lateral decubitus or supine position. The patients were divided into two groups: Group I (unilateral group, n = 23) and Group II (supine group, n = 18). History of hypertension, diabetes mellitus, and ASA status, preoperative value of EF and cardiac index, and intraoperative hypotension, bradycardia, ephedrine use, and maximal sensorial block levels were recorded.

RESULTS

The age range of patients was between 75 and 103. The maximal sensorial block level was evaluated due to lower or higher than thoracic sixth segment for each patient in intraoperative period. The sensorial block level higher than thoracic sixth segment were determined 2 patient in Group I and 14 patients in Group II (p = 0.001). Hypotension was observed in five patients in Group I and 10 patients in Group II (p = 0.015). In Group I, the number of ephedrine used patient was lower than Group II (p = 0.015).

CONCLUSIONS

Elderly patients with low EF were more likely to predispose to higher sensorial block level and hypotension was more common during spinal anaesthesia with supine position compared to lateral decubitus position.

Outpatient arthroscopic knee surgery under combined local and intravenous propofol anesthesia in children and adolescents

BACKGROUND

This prospective observational study included a case series of children and adolescents receiving light intravenous propofol anesthesia combined with local anesthesia (LA) for arthroscopic knee procedures. The aim was to examine the merits of anesthesia, to discuss the indications for the procedure and to analyze recovery/discharge times from the postanesthesia care unit (PACU).

METHODS

A cohort of 147 children and adolescents (ASA 1 and 2) aged 12-18 years admitted for outpatient arthroscopic knee procedures between January 2004 and May 2005 were studied. After IV access in the operating theater, the patients received propofol (10 mg.ml(-1)). Arthroscopy was performed approximately 15 min after injecting local anesthetic (15 ml 2% lidocaine with epinephrine 1:200,000) partly at the site of insertion of the arthroscope and other instruments (5 ml), and the rest intra-articular. The following parameters were assessed: airway patency, propofol requirement, vital signs, procedure time, surgical operating conditions, patient satisfaction score, time to discharge, postoperative analgesia and adverse events.

RESULTS

Of 147 patients, 133 patients (90.5%) underwent arthroscopic knee surgery, whereas knee arthroscopy alone was performed in 14 patients (9.5%) without indication for operative treatment. The arthroscopy was well tolerated in 96.6% patients (no pain, movement or discomfort during the procedure) and only five patients required conversion to general anesthesia. Pain experienced during the injection of lidocaine was more severe than pain experienced during the surgical procedure itself (P < 0.001). The surgical evaluation of operative conditions (visualization and access to intra-articular structures) was generally satisfactory and completely acceptable. Almost 94% (138/147) of patients said they would have the same procedure again under the same type of anesthesia. The mean propfol induction dose was 1.4 mg.kg(-1) (range: 0.9-3.8) and mean propofol infusion rate 167 microg.kg(-1).min(-1) (range: 130-250). Movement was more likely at lower infusion rates (mean: 151 microg.kg(-1).min(-1)). The maximal decrease in respiratory rate was 5.9 +/- 5.1 br.min(-1) (27.2 +/- 21%) and no patient became hypoxic. Patients recovered to preoperative values at 9.8 +/- 7.5 min following infusion discontinuation. There were no respiratory or cardiovascular complications. The mean stay in PACU was 47 min (range: 32-150). As many as 71% (105/147) of patients required no analgesics during the first two postoperative hours.

CONCLUSIONS

The combination of light intravenous propofol anesthesia combined with local anesthesia for arthroscopic knee procedures provided effective sedation, good preservation of upper airway patency, rapid recovery and pain relief without major side effects and offers a good alternative to the methods already available. The majority of patients did not require postoperative analgesia.

Low-dose bupivacaine spinal anaesthesia for percutaneous nephrolithotomy: the suitability and impact of adding intrathecal fentanyl

BACKGROUND

Unilateral spinal anaesthesia has been used for lower limb surgery with a stable cardiovascular state and a short recovery unit stay. We sought to test the suitability of low-dose bupivacaine spinal anaesthesia for percutaneous nephrolithotomy, a procedure hitherto performed under general anaesthesia. Furthermore, we hypothesized that adding intrathecal fentanyl to bupivacaine may improve the quality of anaesthesia.

METHODS

We randomly allocated, through computer-generated randomization, 108 patients subjected to percutaneous nephrolithotomy to receive either 7.5 mg of hyperbaric bupivacaine 5 mg/ml alone or with the addition of 10 microg of fentanyl. Drugs were given at the L(2)-L(3) interspace with the patient in the lateral decubitus position. The patients remained in this position for 10 min, after which the sensory and motor blocks were assessed. Intra-operative analgesic supplementation, when deemed necessary, was achieved with intravenous fentanyl boluses (25 microg).

RESULTS

The sensory and motor blocks after intrathecal bupivacaine and bupivacaine-fentanyl were similar. Sensory block, in both groups, reached the fifth and eighth thoracic dermatomes on the operative and non-operative sides, respectively. Deep motor block occurred on the operative side in all patients and in nearly 50% of patients on the non-operative side. The patients in the bupivacaine-fentanyl group required less intra-operative and post-operative analgesics, and both patients and endoscopists were better satisfied.

CONCLUSION

This study demonstrated, for the first time, that intrathecal low-dose bupivacaine and fentanyl offers a reliable neuraxial block for patients subjected to percutaneous nephrolithotomy, with stable haemodynamics, good post-operative analgesia and acceptable patient and endoscopist satisfaction.

Intrathecal 2-Chloroprocaine for Lower Limb Outpatient Surgery: A Prospective, Randomized, Double-Blind, Clinical Evaluation

We evaluated the dose-response relationship of 2-chloroprocaine for lower limb outpatient procedure in 45 ASA physical status I-II outpatients undergoing elective lower limb surgery under spinal anesthesia, with 30 mg (group Chlor-30, n = 15), 40 mg (group Chlor-40, n = 15), or 50 mg (group Chlor-50, n = 15) of 1% preservative free 2-chloroprocaine. Onset time was similar in the three groups. General anesthesia was never required to complete surgery. Intraoperative analgesic supplementation as a result of insufficient duration of spinal block was required in 5 patients of group Chlor-30 (35%) and 2 patients of group Chlor-40 (13%) (P = 0.014), with a median (range) time for supplementation request of 40 (30-60) min. Spinal block resolution and recovery of ambulation were faster in group Chlor-30 (60 [41-98] min and 85 [45-123] min) than in groups Chlor-40 (85 [46-141] min and 180 [72-281] min) and Chlor-50 (97 [60-169] min and 185 [90-355] min) (P = 0.001 and P = 0.003, respectively), with no differences in home discharge time (182 [120-267] min in group Chlor-30, 198 [123-271] min in group Chlor-40, and 203 [102-394] min in group Chlor-50; P = 0.155). No transient neurologic symptoms were reported at 24-h and 7-day follow-up. We conclude that although 40 and 50 mg of 2-chloroprocaine provide adequate spinal anesthesia for outpatient procedures lasting 45-60 min, 30 mg produces a spinal block of insufficient duration.

Role of patient posture during puncture on successful unilateral spinal anaesthesia in outpatient lower abdominal surgery

BACKGROUND AND OBJECTIVE

Unilateral spinal anaesthesia is a useful anaesthesia technique in lower abdominal surgery, especially in an outpatient setting. Patient posture is pivotal in the achievement of unilateral anaesthesia. Nevertheless, no studies have elucidated the influence of patient posture during the anaesthetic injection on unilaterality. Thus, the aim was to compare the effect of patient posture, during the induction phase of spinal anaesthesia, on block characteristics.

METHODS

Eighty patients, ASA I-II, scheduled for unilateral hernioplasty were randomized into two groups. Anaesthesia was performed in lateral position in Group 1 (G1) with operative side down and in sitting position in Group 2 (G2) whose patients were then immediately turned on their lateral side. All patients were maintained for 20 min in lateral position with their operative side down. Hyperbaric bupivacaine 1% 10 mg were used.

RESULTS

Unilateral anaesthesia was seen in 80% (32/40) and 12.5% (5/40) of G1 and G2, respectively. The readiness for surgery was faster in G1 (P < 0.0001). The motor block in the non-operative side was stronger in G2 (P < 0.0001). The offset of sensory block was faster in G1 (P = 0.0001). The offset of motor block was slower in G1 (P = 0.0008). The time for voiding was shorter in G1, although not significant.

CONCLUSIONS

Lateral posture during the induction of spinal anaesthesia is pivotal for a higher success of unilateral block, a fast readiness to surgery, and a fast recovery. Therefore, this technique can be considered feasible and time-saving for lower abdominal surgery.

Spinal anesthesia with hyperbaric levobupivacaine and ropivacaine for outpatient knee arthroscopy: a prospective, randomized, double-blind study

To compare unilateral spinal block produced with small doses of hyperbaric ropivacaine with that produced by 2 doses of hyperbaric levobupivacaine, we randomly allocated 91 ASA physical status I-II outpatients undergoing knee arthroscopy to receive unilateral spinal anesthesia with 7.5 mg of hyperbaric ropivacaine 0.5% (group Ropi-7.5, n = 31) or either 7.5 mg (group Levo-7.5, n = 30) or 5 mg (group Levo-5, n = 30) of hyperbaric levobupivacaine 0.5%. Spinal anesthesia was performed at the L3-4 interspace using a 25-gauge Whitacre spinal needle. The lateral decubitus position was maintained for 15 min after injection. Strictly unilateral sensory block was present in 73%, 50%, and 61% of cases in groups Ropi-7.5, Levo-7.5, and Levo-5, respectively, 30 min after injection (P = 0.40), and unilateral motor block was observed in 94%, 93%, and 83% in groups Ropi-7.5, Levo-7.5, and Levo-5, respectively (P = 0.31). One patient of group Ropi-7.5 required general anesthesia to complete surgery, and fentanyl supplementation was required in one patient of group Ropi-7.5 (3%) and one patient of group Levo-5 (3%) (P = 0.42). The median (range) time for spinal block resolution was shorter in group Ropi-7.5 (135 [126-154] min] than in group Levo-7.5 (162 [148-201] min) (P = 0.04); whereas home discharge was shorter in groups Ropi-7.5 (197 [177-218] min) and Levo-5 (197 [187-251] min) as compared with group Levo-7.5 (238 [219-277] min) (P = 0.02 and P = 0.04, respectively). We conclude that 7.5 mg of 0.5% hyperbaric ropivacaine and 5 mg of 0.5% hyperbaric levobupivacaine provide adequate spinal block for outpatient knee arthroscopy, with a faster home discharge as compared with 7.5 mg of 0.5% hyperbaric levobupivacaine.

A Comparison of Selective Spinal Anesthesia with Hyperbaric Bupivacaine and General Anesthesia with Desflurane for Outpatient Knee Arthroscopy

In this randomized and controlled trial, 64 adult ambulatory knee arthroscopy patients received either selective spinal anesthesia (SSA) with 4 mg of hyperbaric bupivacaine or general anesthesia (GA) with desflurane. We conducted the study to determine whether SSA with small-dose bupivacaine provides equal fast-tracking possibilities, a shorter stay in the postanesthesia care unit, and earlier discharge home compared with GA with desflurane. Patients with a high risk for postoperative nausea and vomiting received prophylaxis in the GA group. No difference was seen in the fast-tracking possibilities or time in the postanesthesia care unit between the groups. Home readiness was achieved after 114 (31-174) and 129 (28-245) min (NS) in the SSA and GA groups, respectively. In the hospital, the pain scores were significantly (P < 0.001) lower in the SSA group compared with the GA group and the need for postoperative opioids was significantly (P = 0.008) larger after GA. The incidence of postoperative nausea and vomiting was 0% versus 19% in the SSA and GA groups (P = 0.024), respectively. We conclude that for outpatients undergoing knee arthroscopy, SSA with hyperbaric bupivacaine provides equal recovery times with less frequent side effects compared with GA with desflurane.

A prospective, randomized, double-blind comparison of unilateral spinal anesthesia with hyperbaric bupivacaine, ropivacaine, or levobupivacaine for inguinal herniorrhaphy

In 60 patients undergoing inguinal hernia repair, we compared the clinical profile of unilateral spinal anesthesia produced with either 8 mg of hyperbaric bupivacaine 0.5% (n = 20), 8 mg of hyperbaric levobupivacaine 0.5% (n = 20), or 12 mg of hyperbaric ropivacaine 0.5% (n = 20). The study drug was injected slowly through a 25-gauge Whitacre directional needle and patients maintained the lateral decubitus position for 15 min. The onset time and intraoperative efficacy were similar in the three groups. The maximal level of sensory block on the operative and nonoperative sides was T6 (T12-5) and L3 (/[no sensory level detectable]-T4) with bupivacaine, T8 (T12-5) and L3 (/-T3) with levobupivacaine, T5 (T10-2) and T11 (/-T3) with ropivacaine (P = 0.11, P = 0.23, respectively). Complete regression of spinal anesthesia occurred after 166 +/- 42 min with ropivacaine, 210 +/- 63 min with levobupivacaine, and 190 +/- 51 min with bupivacaine (P = 0.03 and P = 0.04, respectively); however, no differences were observed in time for home discharge (329 +/- 89 min with bupivacaine, 261 +/- 112 min with levobupivacaine, and 332 +/- 57 min with ropivacaine [P = 0.28]). We conclude that 8 mg of levobupivacaine or 12 mg of ropivacaine are acceptable alternatives to 8 mg of bupivacaine when limiting spinal block at the operative side for inguinal hernia repair.

A Prospective, Randomized Evaluation of the Effects of Epidural Needle Rotation on the Distribution of Epidural Block

We evaluated the effects of turning the tip of the Tuohy needle 45 degrees toward the operative side before threading the epidural catheter (45 degrees -rotation group, n = 24) as compared to a conventional insertion technique with the tip of the Tuohy needle oriented at 90 degrees cephalad (control group, n = 24) on the distribution of 10 mL of 0.75% ropivacaine with 10 microg sufentanil in 48 patients undergoing total hip replacement. The catheter was introduced 3 to 4 cm beyond the tip of the Tuohy needle. A blinded observer recorded sensory and motor blocks on both sides, quality of analgesia, and volumes of local anesthetic used during the first 48 h of patient-controlled epidural analgesia. Readiness to surgery required 21 +/- 6 min in the control group and 17 +/- 7 min in the 45 degree-rotation group (P > 0.50). The maximum sensory level reached on the operative side was T10 (T10-7) in the control group and T9 (T10-6) in the 45 degree-rotation group (P > 0.50); whereas the maximum sensory level reached on the nonoperative side was T10 (T12-9) in the control group and L3 (L5-T12) in the 45 degree-rotation group (P = 0.0005). Complete motor blockade of the operative limb was achieved earlier in the 45 degree-rotation than in the control group, and motor block of the nonoperative side was more intense in patients in the control group. Two-segment regression of sensory level on the surgical side was similar in the two groups, but occurred earlier on the nonoperative side in the 45 degree-rotation group (94 +/- 70 min) than in the control group (178 +/- 40 min) (P = 0.0005). Postoperative analgesia was similar in the 2 groups, but the 45 degree-rotation group consumed less local anesthetic (242 +/- 35 mL) than the control group (297 +/- 60 mL) (P = 0.0005). We conclude that the rotation of the Tuohy introducer needle 45 degrees toward the operative side before threading the epidural catheter provides a preferential distribution of sensory and motor block toward the operative side, reducing the volume of local anesthetic solution required to maintain postoperative analgesia.

IMPLICATIONS

Turning the Tuohy introducer needle 45 degrees toward the operative side before threading the epidural catheter is a simple maneuver that produces a preferential distribution of epidural anesthesia and analgesia toward the operative side, minimizing the volume of local anesthetic required to provide adequate pain relief after total hip arthroplasty.

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.

Unilateral spinal block for outpatient knee arthroscopy: a dose-finding study

STUDY OBJECTIVE

To evaluate the onset time, success rate, and recovery profile of unilateral spinal anesthesia produced with 4 mg, 6 mg, and 8 mg of 0.5% hyperbaric bupivacaine.

DESIGN

Prospective, randomized, blinded study.

SETTING

Outpatient anesthesia unit at a University Hospital.

PATIENTS

90 ASA physical status I and II outpatients, who were scheduled for elective knee arthroscopy.

INTERVENTIONS

After standard intravenous midazolam premedication (0.05 mg/kg) and crystalloid infusion (7 mL/kg) were given, patients were placed in the lateral decubitus position on the operative side, and randomly allocated to receive spinal block with either 4 mg (Group 4, n = 30), 6 mg (Group 6, n = 30), or 8 mg (Group 8, n = 30) of 0.5% hyperbaric bupivacaine injected slowly (3 mL/min) with the needle orifice directed toward the dependent side using a 25-gauge Whitacre needle. The lateral decubitus position was maintained for 15 minutes.

MEASUREMENTS AND MAIN RESULTS

The onset time of surgical block was 13 +/- 5 minutes in Group 4 and 10 +/- 4 minutes in Group 6 (p = 0.006), and 9 +/- 4 minutes in Group 8 (p = 0.002). The maximum level of sensory block on the operative and nonoperative sides was, respectively, T(10) (T(12)-T(6)) and / (/-L(2)) in Group 4 (p = 0.0005), T(8) (T(12)-T(6)) and / (/-L(5)) in Group 6 (p = 0.0005), and T(7) (T(12)-T(5)) and / (/-T(10)) in Group 8 (p = 0.0005). A strictly unilateral sensory block was observed in 27 Group 4 patients (90%), 28 Group 6 patients (93%) and 23 Group 8 patients (77%) (p = 0.28). Complete unilateral motor block was observed in 29 Group 4 patients (97%), 28 Group 6 patients (93%), and 28 Group 8 patients (93%) (p = 0.80). No failed blocks were reported. Complete regression of spinal anesthesia required 71 +/- 20 minutes in Group 4 (range: 40 to 110 min), 82 +/- 25 minutes in Group 6 (range: 30 to 160 min), and 97 +/- 37 minutes in Group 8 (range: 50 to 120 min) (p = 0.003).

CONCLUSIONS

Hyperbaric bupivacaine 4 mg injected slowly through pencil-point directional needles in patients who are maintained in the lateral decubitus position for 15 minutes provided a surgical block that was mostly restricted to the operative side and adequate to perform knee arthroscopy, with a faster recovery profile than when a 6 mg or 8 mg dose was used.

Clonidine combined with small-dose bupivacaine during spinal anesthesia for inguinal herniorrhaphy: a randomized double-blinded study

The aim of this randomized double-blinded study was to see whether the addition of small-dose clonidine to small-dose bupivacaine for spinal anesthesia prolonged the duration of postoperative analgesia and also provided a sufficient block duration that would be adequate for inguinal herniorrhaphy. We randomized 45 patients to 3 groups receiving intrathecal hyperbaric bupivacaine 6 mg combined with saline (Group B), clonidine 15 micro g (Group BC15), or clonidine 30 micro g (Group BC30); all solutions were diluted with saline to 3 mL. The sensory block level was insufficient for surgery in five patients in Group B, and these patients were given general anesthesia. Patients in Groups BC15 and BC30 had a significantly higher spread of analgesia (two to four dermatomes) than those in Group B. Two-segment regression, return of S1 sensation, and regression of motor block were significantly longer in Group BC30 than in Group B. The addition of clonidine 15 and 30 micro g to bupivacaine prolonged time to first analgesic request and decreased postoperative pain with minimal risk of hypotension. We conclude that clonidine 15 micro g with bupivacaine 6 mg produced an effective spinal anesthesia and recommend this dose for inguinal herniorrhaphy, because it did not prolong the motor block.

IMPLICATIONS

The addition of clonidine 15 micro g to 6 mg of hyperbaric bupivacaine increases the spread of analgesia, prolongs the time to first analgesic request, and decreases postoperative pain, compared with bupivacaine alone, during inguinal herniorrhaphy under spinal anesthesia.