Transient Neurologic Symptoms after Spinal Anesthesia with Mepivacaine and Lidocaine

Background: Spinal anesthesia with lidocaine is ideal for ambulatory surgery because of its short duration of action. However, transient neurologic symptoms (TNS) occur in 0-40% of patients. The incidence of TNS with mepivacaine, which has a similar duration of action, is unknown.

Methods: Sixty ambulatory patients undergoing knee arthroscopy received spinal anesthesia in a randomized, double-blinded manner, with either 45 mg 1.5% mepivacaine or 60 mg 2% lidocaine. An L3-L4 midline approach was used with a 27-gauge Whitacre needle and a 20-gauge introducer. The local anesthetic was injected over approximately 30 s with the aperture of the Whitacre needle in a cephalad direction. Two to 4 days after operation, each patient was questioned about the development of TNS. In addition, the two groups were compared for time to regression of sensory and motor blockade and time to discharge milestones.

Results: Three patients receiving lidocaine were lost to follow-up. None of the 30 patients in the mepivacaine group developed TNS, whereas 6 of 27 (22%) in the lidocaine group did (P = 0.008). Time to regression to the L5 sensory level and to complete resolution of motor block were similar in both groups. The times to discharge milestones were also comparable.     

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 μg (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 μg 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).     

Anesthetic and recovery profiles of lidocaine versus mepivacaine for spinal anesthesia in patients undergoing outpatient orthopedic arthroscopic procedures

Study ObjectiveTo compare isobaric lidocaine and mepivacaine in outpatient arthroscopic surgery.DesignProspective, randomized, double-blinded study.SettingAmbulatory surgery center affiliated with an academic tertiary-care hospital.Patients84 adult, ASA physical status 1, 2, and 3 ambulatory patients, age 18-70 years, undergoing arthroscopic knee surgery.InterventionPatients were randomized to receive a combination spinal-epidural anesthetic using 80 mg of either isobaric 2% mepivacaine or isobaric 2% lidocaine. Patients also received a femoral 3-in-1 block with 0.5% bupivacaine applied to the affected extremity.MeasurementsDemographic data and level and duration of the block were recorded. The use of supplemental epidural anesthesia was noted along with frequency of bradycardia, hypotension, and episodes of nausea and vomiting. Duration of block and times to ambulation and voiding were recorded. Delayed variables, including fatigue, difficulty urinating, back pain, and transient neurologic symptoms (TNS) were obtained.Main ResultsNo demographic differences were noted between groups, and surgical duration was similar. Satisfactory anesthesia was achieved in all cases, with no differences noted in hypotension, bradycardia, nausea, or vomiting. Onset of sensory and motor block was similar. Duration of block before epidural supplementation was 94 ± 21 minutes with lidocaine versus 122 ± 23 minutes for mepivacaine (P < 0.011). Times to ambulation and voiding were longer in patients receiving mepivacaine but did not affect PACU stay. Twenty-four and 48-hour recovery was similar with no TNS symptoms reported.ConclusionNo major differences were noted between lidocaine and mepivacaine spinal anesthesia. Time to ambulation and voiding were longer in patients who received mepivacaine as was time to first dose of epidural catheter. Neither group had TNS symptoms. Lidocaine and mepivacaine are both appropriate spinal anesthetics for ambulatory orthopedic lower extremity procedures.     

Intrathecal ropivacaine and clonidine for ambulatory knee arthroscopy: a dose-response study

BACKGROUND: The aim of this study was to evaluate the association of a small dose of intrathecal ropivacaine with small doses of intrathecal clonidine for ambulatory surgery. METHODS: One hundred twenty patients, classified as American Society of Anesthesiologists physical status I and scheduled for knee arthroscopy, were studied. Patients were randomly assigned to receive 4 ml of one of the following double-blinded isobaric intrathecal solutions: 8 mg of ropivacaine (group 1; n =30); 8 mg ropivacaine plus 15 microg clonidine (group 2; n =30); 8 mg ropivacaine plus 45 microg clonidine (group 3; n =30); and 8 mg ropivacaine plus 75 microg clonidine (group 4; n =30). The level and duration of sensory anesthesia were recorded, along with the intensity and duration of motor block. Patient and surgeon were interviewed to evaluate the quality of anesthesia. RESULTS: Intrathecal ropivacaine (8 mg alone) produced short sensory anesthesia and motor blockade (132 +/- 38 min and 110 +/- 35 min; mean +/- SD). However, the quality of anesthesia was significantly lower than in any other group (P < 0.05). Ropivacaine (8 mg) plus 75 microg clonidine produced significantly longer sensory and motor anesthesia (195 +/- 40 min and 164 +/- 38 min; P < 0.05). However, this was associated with systemic effects, such as sedation and reduction of arterial blood pressure. Ropivacaine (8 mg) plus 15 microg clonidine did not prolong sensory or motor blockade, afforded high quality anesthesia, and was not associated with detectable systemic effects. CONCLUSION: Small-dose intrathecal clonidine (15 microg) plus 8 mg intrathecal ropivacaine produces adequate and short-lasting anesthesia for knee arthroscopy.     

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

Reports of transient neurological symptoms with the use of subarachnoid lidocaine has generated interest in alternate local anesthetics of intermediate duration, such as mepivacaine. This prospective randomized, double-blinded, dose-response study examined the anesthetic and recovery profiles of 60- and 80-mg doses of preservative-free plain mepivacaine for ambulatory spinal anesthesia. Sixty patients undergoing ambulatory anterior cruciate ligament repair of the knee under spinal anesthesia were randomized into two groups; Group 1 (29 patients) received 4 mL of 1.5% (60-mg dose) and Group 2 (31 patients) received 4 mL of 2% (80-mg dose) of plain mepivacaine. All patients received a combined spinal-epidural anesthetic technique. The epidural catheter was used only in the event the surgery outlasted the duration of surgical anesthesia with subarachnoid mepivacaine. Epidural supplementation was administered in three patients (12%) in Group 1 and one patient (3%) in Group 2 when the sensory block regressed to L-1 with surgery expected to last longer than 15 min. The cephalad dermatome level of the block and degree of motor block was comparable in the two groups. Times to two-segment and T-10 regression were comparable in the two groups (112 +/- 26 min in Group 1 versus 122 +/- 28 min in Group 2). Time to L-1 regression was significantly longer in Group 2 (146 +/- 28 min in Group 1 versus 159 +/- 19 min in Group 2). All of the ambulatory milestones were significantly faster in Group 1. Side effects, such as hypotension and emesis were negligible, severe bradycardia and urinary retention did not occur, and none of the patients in the two groups reported transient neurological symptoms over 24 h. In conclusion, plain mepivacaine in a 60- or 80-mg dose is a suitable local anesthetic choice for ambulatory spinal anesthesia with respect to anesthetic, as well as recovery profiles. IMPLICATIONS: We evaluated the anesthetic and recovery profiles of 60- and 80-mg doses of plain mepivacaine for ambulatory spinal anesthesia. Both doses produced comparable sensory and motor block. Sensory and motor regression and ambulatory milestones were 20-30 min longer with the 80-mg dose. Side effects were negligible and transient neurological symptoms were not reported during a 24-h follow-up.     

Transient neurologic symptoms after spinal anaesthesia using isobaric 2% mepivacaine and isobaric 2% lidocaine

BACKGROUND: Transient Neurological Symptoms (TNS) syndrome following subarachnoid anaesthesia was initially associated with hyperbaric lidocaine 50 mg/ml, but has also been reported with most local anaesthetics, including hyperbaric mepivacaine 40 mg/ml. The aim of this study was to determine the incidence of TNS after subarachnoid anaesthesia using isobaric mepivacaine 20 mg/ml and isobaric lidocaine 20 mg/ml. METHODS: Eighty patients of both sexes, ASA class I-II, scheduled for elective minor orthopaedic surgery under subarachnoid anaesthesia, were prospectively included and randomly allocated to receive 40-60 mg of either isobaric mepivacaine 20 mg/ml (Group M) or isobaric lidocaine 20 mg/ml (Group L). Patients were evaluated on the first postoperative day by one investigator unaware of the grouping, looking for symptoms suggestive of TNS, such as pain or dysaesthesias in the buttocks or lower limbs with or without back pain. RESULTS: TNS symptoms were observed in three patients (7.5%) of Group M and in one patient (2.5%) of Group L, without statistically significant differences between the groups. Symptoms had an abrupt onset and relief, lasted from 45 min to 24 h, and had a complete resolution without sequelae. The only statistically significant difference between groups was longer motor blockade in Group M (P=0.0031). CONCLUSION: In this study TNS was associated with isobaric mepivacaine 20 mg/ml, with an incidence of 7.5%, and with isobaric lidocaine 20 mg/ml, with an incidence of 2.5%, in patients having orthopaedic procedures in the supine position.     

The incidence of transient neurologic symptoms after spinal anesthesia with mepivacaine

We prospectively evaluated 1273 patients who received spinal (or combined spinal-epidural [CSE]) anesthesia with 1.5% mepivacaine (plain, no glucose) for ambulatory surgery. We hypothesized that analysis of a large series of patients would confirm previous findings that isobaric 1.5% mepivacaine is not frequently associated with transient neurologic symptoms (TNS). Patients were contacted twice after the anesthetic, at days 1-4 and days 6-9. One-thousand-two-hundred-ten patients were successfully contacted postoperatively (95% follow-up rate). None of the patients had permanent neurologic sequelae from the anesthetic. None of the 372 CSE anesthetics was inadequate for surgery. Fourteen of 838 (1.7%) of the spinal anesthetics were inadequate. TNS, defined as the new onset of back pain that radiated bilaterally to buttocks or distally, occurred in 78 patients (6.4%; 95% confidence intervals 5.1%-8%). The mean age of patients who developed TNS (48 +/- 14 yr) was older than that of patients without TNS (41 +/- 16 yr) (P < 0.001). TNS was not influenced by gender or intraoperative position. The frequent success rate and infrequent rates of complications such as TNS and postdural puncture headache suggest that spinal anesthesia with mepivacaine is likely to be a safe and effective anesthetic for ambulatory patients.     

The influence of ambulation time on the incidence of transient neurologic symptoms after lidocaine spinal anesthesia

The cause of transient neurologic symptoms (TNSs) after lidocaine spinal anesthesia remains unclear. It has been proposed that early ambulation after spinal anesthesia contributes to the development of TNSs. We evaluated the influence of ambulation time on the occurrence of TNSs after spinal anesthesia with 50 mg of 2% plain lidocaine for knee arthroscopy. One-hundred-twenty patients undergoing knee arthroscopy (ASA physical status 1-2) were randomized into 3 groups, i.e., early (Group E), 6-h (Group 6-h), or late ambulation (Group L) groups. In Group E, ambulation was allowed as early as possible after regression of spinal block (on average 229 +/- 21 min; range, 135-247 min). In Group 6-h, the patients remained in bed for approximately 6 h after the block and in Group L until the next morning. The patient groups were comparable with respect to demographic, anesthetic, and surgical variables. The overall incidence of TNSs was 16%. TNSs occurred in 3 patients of Group E (7.5%), in 11 patients of Group 6-h (28%), and in 5 patients of Group L (13%). No significant differences were detected between the patients with and without TNSs. Early ambulation was not found to be a risk factor for TNSs after spinal anesthesia with 50 mg of 2% lidocaine. IMPLICATIONS: This study shows that early ambulation time does not increase the incidence of transient neurologic symptoms after spinal anesthesia with 50 mg of 2% lidocaine for elective knee arthroscopy.     

Transient neurological symptoms after spinal anaesthesia with levobupivacaine 5 mg/ml or lidocaine 20 mg/ml

Background: Transient neurological symptoms (TNS) after spinal anaesthesia have been reported most commonly in association with lidocaine, but have been observed with other local anaesthetics. The aim of this prospective, randomized, double-blind study was to investigate the incidence of TNS after spinal anaesthesia with either levobupivacaine or lidocaine.
Methods: Patients undergoing inguinal hernia, appendectomy, varicose vein or minor orthopaedic operations were included in the study (60 patients; 47 male, 13 female, overall mean age 30 years). All patients had an American Society of Anesthesiologists score of I or II. The patients were randomly assigned to receive spinal anaesthesia with either 20 mg isobaric levobupivacaine (5 mg/ml) or 80 mg isobaric lidocaine (20 mg/ml). Onset of sensory and motor block and side effects were recorded. On post-operative days 1, 2, and 3, patients were interviewed by an investigator blinded to the spinal anaesthetic used. The patients were classified as having TNS if, following recovery from anaesthesia, there was pain in the buttocks, thighs and/or lower limbs.
Results: In the levobupivacaine group, one patient (3.33%) experienced TNS, whereas in the lidocaine group, eight (26.6%) experienced TNS ( P =0.002). Maximum times to arrival of sensory blocks were shorter with lidocaine ( P <0.001). The levobupivacaine and lidocaine groups did not differ significantly in terms of the highest dermatome included in sensory block or motor block grade.
Conclusion: After spinal anaesthesia with levobupivacaine, the incidence of TNS was much less than after lidocaine. However, it appears that TNS may occur in association with levobupivacaine.     

Onset of spinal block is more rapid with isobaric than hyperbaric bupivacaine

PURPOSE: To compare isobaric with hyperbaric 9.75 mg bupivacaine injected intrathecally, and to evaluate the effects of subsequent injection of lidocaine 2% into the epidural space. METHODS: Patients in group 1 (n = 30) received isobaric 9.75 mg bupivacaine and in group 2 (n = 30) hyperbaric 9.75 mg bupivacaine injected into the subarachnoid space in a combined spinal-epidural technique. They were undergoing urological, gynecological, orthopedic, gastro-intestinal or vascular surgery. Using a double blind technique, the followings parameters were measured: cutaneous analgesia to pinprick, motor blockade, time for two segment regression, time for complete regression of the motor block, quality of anesthesia. In 12 patients the effect of epidural injections of 3 ml lidocaine 2% was observed. RESULTS: Motor and sensory block developed more rapidly (five minutes) in the isobaric group (P<0.05). Maximum upper level (T7+/-2), two-segment regression (52 min in both groups), motor recovery (160 vs. 157 min), and quality of anesthesia did not differ between the two groups. Thirty nine epidural injections of 3 ml lidocaine 2% were given in 12 patients 10 min after spinal injection, 28 were in the hyperbaric group (P<0.05). Twenty six of the epidural injections produced an increase in sensory block of 0 or 1 dermatome, and 13, of 2 or more. CONCLUSION: The block developed more rapidly in the isobaric group, but both isobaric and hyperbaric 9.75 mg bupivacaine produced adequate upper levels of analgesia for surgery. The effect of epidural injections of 3 ml lidocaine 2% was usually minimal.     

Intrathecal Ropivacaine and Clonidine for Ambulatory Knee Arthroscopy: A Dose-Response Study

Background: The aim of this study was to evaluate the association of a small dose of intrathecal ropivacaine with small doses of intrathecal clonidine for ambulatory surgery.

Methods: One hundred twenty patients, classified as American Society of Anesthesiologists physical status I and scheduled for knee arthroscopy, were studied. Patients were randomly assigned to receive 4 ml of one of the following double-blinded isobaric intrathecal solutions: 8 mg of ropivacaine (group 1; n =30); 8 mg ropivacaine plus 15 [mu]g clonidine (group 2; n =30); 8 mg ropivacaine plus 45 [mu]g clonidine (group 3; n =30); and 8 mg ropivacaine plus 75 [mu]g clonidine (group 4; n =30). The level and duration of sensory anesthesia were recorded, along with the intensity and duration of motor block. Patient and surgeon were interviewed to evaluate the quality of anesthesia.

Results: Intrathecal ropivacaine (8 mg alone) produced short sensory anesthesia and motor blockade (132 +/- 38 min and 110 +/- 35 min; mean +/- SD). However, the quality of anesthesia was significantly lower than in any other group (P < 0.05). Ropivacaine (8 mg) plus 75 [mu]g clonidine produced significantly longer sensory and motor anesthesia (195 +/- 40 min and 164 +/- 38 min;P < 0.05). However, this was associated with systemic effects, such as sedation and reduction of arterial blood pressure. Ropivacaine (8 mg) plus 15 [mu]g clonidine did not prolong sensory or motor blockade, afforded high quality anesthesia, and was not associated with detectable systemic effects.     

A comparison of minidose lidocaine-fentanyl and conventional-dose lidocaine spinal anesthesia

The syndrome of transient neurologic symptoms (TNS) after spinal lidocaine has been presumed to be a manifestation of local anesthetic neurotoxicity. Although TNS is not associated with either lidocaine concentration or dose, its incidence has never been examined with very small doses of spinal lidocaine. One hundred ten adult ASA physical status I and II patients presenting for arthroscopic surgery of the knee were randomly assigned to receive spinal anesthesia with either 1% hypobaric lidocaine 50 mg (Group L50) or 1% hypobaric lidocaine 20 mg + 25 microg fentanyl (Group L20/F25). Hemodynamic data, block height and regression, and time to first micturition and discharge were recorded. Follow-up phone calls were made by a blinded researcher at 48-72 h using a standardized questionnaire. Both groups had a median peak cephalad block level of T10. Lidocaine 50 mg was associated with a greater decrease in systolic blood pressure and a greater need for ephedrine. Time until block regression to the S2 dermatome (80 vs. 110 min) and outpatient time to void (130 vs 162 min) and discharge (145 vs. 180 min) were faster in the L20/F25 group. Complaints of TNS were found in 32.7% of the patients in the L50 group and in 3.6% of the patients in the L20/F25 group. We conclude that spinal anesthesia with lidocaine 20 mg + fentanyl 25 microg provided adequate anesthesia with greater hemodynamic stability and faster recovery than spinal anesthesia with lidocaine 50 mg. The incidence of TNS after spinal lidocaine 20 mg + fentanyl 25 microg was significantly less than that after spinal lidocaine 50 mg.     

Spinal 2-chloroprocaine: a comparison with lidocaine in volunteers

Subarachnoid lidocaine has been the anesthetic of choice for outpatient spinal anesthesia. However, its use is associated with transient neurologic symptoms (TNS). Preservative-free formulations of 2-chloroprocaine are now available and may compare favorably with lidocaine for spinal anesthesia. In this double-blinded, randomized, crossover study, we compared spinal chloroprocaine and lidocaine in 8 volunteers, each receiving 2 spinal anesthetics: 1 with 40 mg 2% lidocaine and the other with 40 mg 2% preservative-free 2-chloroprocaine. Pinprick anesthesia, tolerance to transcutaneous electrical stimulation and thigh tourniquet, motor strength, and a simulated discharge pathway were assessed. Chloroprocaine produced anesthetic efficacy similar to lidocaine, including peak block height (T8 [T5-11] versus T8 [T6-12], P = 0.8183) and tourniquet tolerance (46 +/- 6 min versus 38 +/- 24 min, P = 0.4897). Chloroprocaine anesthesia resulted in faster resolution of sensory (103 +/- 13 min versus 126 +/- 16 min, P = 0.0045) and more rapid attainment of simulated discharge criteria (104 +/- 12 min versus 134 +/- 14 min, P = 0.0007). Lidocaine was associated with mild to moderate TNS in 7 of 8 subjects; no subject complained of TNS with chloroprocaine (P = 0.0004). We conclude that the anesthetic profile of chloroprocaine compares favorably with lidocaine. Reliable sensory and motor blockade with predictable duration and minimal side effects make chloroprocaine an attractive choice for outpatient spinal anesthesia. IMPLICATIONS: The spinal anesthetic profile of chloroprocaine (40 mg) compares favorably with the same dose of spinal lidocaine. Reliable sensory and motor blockade with predictable duration and minimal side effects and without signs of transient neurological symptoms make chloroprocaine an attractive choice for outpatient spinal anesthesia.     

Intrathecal Ropivacaine for Ambulatory Surgery: A Comparison between Intrathecal Bupivacaine and Intrathecal Ropivacaine for Knee Arthroscopy

Background: The rationale of this study was to evaluate intrathecal ropivacaine for ambulatory surgery.

Methods: One hundred fifty patients with American Society of Anesthesiologists physical status 1 scheduled for knee arthroscopy were studied. Patients were randomly assigned to receive 4 ml of one of five isobaric intrathecal solutions: Patients in group 1 (n = 30) received 8 mg of bupivacaine; patients in group 2 (n = 30) received 8 mg ropivacaine; patients in group 3 (n = 30) received 10 mg ropivacaine; patients in group 4 (n = 30) received 12 mg ropivacaine; and patients in group 5 (n = 30) received 14 mg ropivacaine. The level and duration of sensory anesthesia were recorded along with the intensity and duration of motor block. Patients were interviewed to identify transient neurologic symptoms.

Results: Intrathecal ropivacaine 10 mg produced shorter sensory anesthesia and motor blockade than bupivacaine 8mg (152 +/- 44 min and 135 +/- 41 min vs. 181 +/- 44 min and 169 +/- 52 min, mean +/- SD;P < 0.05). However, the quality of intraoperative analgesia was significantly lower in the 10-mg ropivacaine group (P < 0.05). Ropivacaine 12 mg produced sensory and motor block almost comparable to bupivacaine 8 mg. Ropivacaine 14 mg produced sensory and motor block comparable to ropivacaine 12 mg but significantly increased the time to void. No sign of transient radicular irritation were noted.     

Low dose of lidocaine: comparison of 15 with 20 mg/ml with dextrose for spinal anesthesia in lithotomy position and ambulatory surgery

Background: Spinal anesthesia with the local anesthetic lidocaine has come under scrutiny because it is associated with transient neurologic symptoms (TNS). Although TNS is not associated with either lidocaine concentration or dose, its incidence has never been examined with very small doses of hyperbaric spinal lidocaine in patients in the lithotomy position. We designed this study prospectively to compare the efficacy of low-dose 15 mg/ml with low-dose 20 mg/ml hyperbaric lidocaine in patients undergoing elective outpatient surgery in the lithotomy position.
Methods: A total of 100 patients were randomized to receive either 30 mg of 15 mg/ml or the same dose of 20 mg/ml hyperbaric lidocaine. Lidocaine density at 37 °C is 1.0241 g/ml for the 15 mg/ml and 1.0260 g/ml for the 20 mg/ml solution. Patients were examined for motor block, sensory block, and block duration. Patients were contacted at 24, 48 and 72 h and questioned about their perceptions of pain after the spinal anesthesia with specific questions designed to diagnose TNS.
Results: The spread of analgesia was the same with both solutions of lidocaine. Motor block was incomplete in all patients in both groups. TNS were not observed when low doses of both solutions of lidocaine with dextrose were used in these ambulatory patients in the lithotomy position.
Conclusion: Hyperbaric lidocaine results in rapid recovery from sensory block and motor blockade. It may have advantages for patients in a day-case setting. No patients complained of TNS after discharge.     

Intrathecal ropivacaine for ambulatory surgery.

BACKGROUND: The rationale of this study was to evaluate intrathecal ropivacaine for ambulatory surgery. METHODS: One hundred fifty patients with American Society of Anesthesiologists physical status 1 scheduled for knee arthroscopy were studied. Patients were randomly assigned to receive 4 ml of one of five isobaric intrathecal solutions: Patients in group 1 (n = 30) received 8 mg of bupivacaine; patients in group 2 (n = 30) received 8 mg ropivacaine; patients in group 3 (n = 30) received 10 mg ropivacaine; patients in group 4 (n = 30) received 12 mg ropivacaine; and patients in group 5 (n = 30) received 14 mg ropivacaine. The level and duration of sensory anesthesia were recorded along with the intensity and duration of motor block. Patients were interviewed to identify transient neurologic symptoms. RESULTS: Intrathecal ropivacaine 10 mg produced shorter sensory anesthesia and motor blockade than bupivacaine 8mg (152 +/- 44 min and 135 +/- 41 min vs. 181 +/- 44 min and 169 +/- 52 min, mean +/- SD; P < 0.05). However, the quality of intraoperative analgesia was significantly lower in the 10-mg ropivacaine group (P < 0.05). Ropivacaine 12 mg produced sensory and motor block almost comparable to bupivacaine 8 mg. Ropivacaine 14 mg produced sensory and motor block comparable to ropivacaine 12 mg but significantly increased the time to void. No sign of transient radicular irritation were noted. CONCLUSION: Intrathecal ropivacaine 12 mg is approximately equivalent to bupivacaine 8 mg. At this dose, ropivacaine offers no significant advantage compared with bupivacaine.     

Isobaric versus hypobaric spinal bupivacaine for total hip arthroplasty in the lateral position

Total hip arthroplasty (THA) is frequently performed under spinal anesthesia using either isobaric or hypobaric anesthetic solution. However, these two solutions have never been compared under similar surgical conditions. In the present study, we compared the anesthetic and hemodynamic effects of isobaric and hypobaric bupivacaine in 40 ASA physical status I-II patients undergoing THA in the lateral decubitus position under spinal anesthesia. With operative side up, patients randomly received, in a double-blinded manner, a spinal injection of 3.5 mL (17.5 mg) of plain bupivacaine mixed with either 1.5 mL of normal saline (isobaric group) or 1.5 mL of distilled water (hypobaric group). Sensory level and degree of motor block were evaluated on the nondependent and dependent sides until regression to L2 and total motor recovery. Hemodynamic changes during the first 45 min after spinal injection, and the time between spinal administration and first analgesic for a pain score >3 (on a 0-10 scale) were noted. Demographic characteristics of both groups were comparable. Upper sensory level and maximal degree of motor block were comparable between the operative and nonoperative sides in each group and between corresponding sides in both groups. Compared with the isobaric group, in the hypobaric group there was a prolonged time to sensory regression to L2 on the operative side (287 +/- 51 versus 242 +/- 36 min, P < 0.004) and a prolonged time to first analgesic (290 +/- 46 versus 237 +/- 39 min, P < 0.001). No difference in quality of motor block was noted at the end of surgery. Hemodynamic changes were comparable. We conclude that for THA in the lateral position, spinal hypobaric bupivacaine seems to be superior to isobaric in that it prolongs the sensory block on the operative side and delays the use of analgesics after surgery without further compromising hemodynamic stability. IMPLICATIONS: For total hip arthroplasty in the lateral position, spinal hypobaric bupivacaine compared with isobaric prolonged sensory block at the operative side and delayed the time to first analgesic.     

Small-dose intrathecal lidocaine versus ropivacaine for anorectal surgery in an ambulatory setting

Spinal anesthesia with the local anesthetic lidocaine has come under scrutiny because it is associated with transient neurologic symptoms (TNS). We designed this study to prospectively compare the efficacy of ropivacaine as an alternative to lidocaine in patients undergoing elective outpatient anorectal procedures. Seventy-two patients were randomized to receive either hyperbaric lidocaine 25 mg with fentanyl 20 microg (n = 37) or hyperbaric ropivacaine 4 mg with fentanyl 20 microg (n = 35). Patients were examined for motor block, sensory block, and block duration. Patients were contacted at 24, 48, 72, and 168 h and questioned about their perceptions of pain after the spinal with specific questions designed to diagnose TNS. There were no patients with TNS in either group. There was no significant difference between the lidocaine and ropivacaine groups in any of the outcomes studied. In conclusion, intrathecal hyperbaric small-dose ropivacaine with fentanyl is an acceptable anesthetic for anorectal surgery. IMPLICATIONS: In this prospective trial, small-dose ropivacaine with fentanyl was as effective as small-dose lidocaine with fentanyl for anorectal procedures in the ambulatory setting.     

Spainal anesthesia improves the early recovery profile of patients undergoing ambulatory knee arthroscopy

PURPOSE: We compared the recovery profiles, postoperative complications, perioperative OR utilization times, and times to discharge of patients undergoing ambulatory knee arthroscopy under spinal anesthesia (SA) or general anesthesia (GA). METHODS: In this randomized, prospective study, 84 ASA I-II patients were randomized to receive either SA with 50 mg of 1% lidocaine, or a standardized GA. Postoperative pain, nausea and vomiting, sedation, OR utilization, postanesthesia care unit (PACU), and ambulatory surgical unit (ASU) recovery were compared. RESULTS: Patients in the GA group had more pain in the PACU than the SA group (61% vs 15%, P <0.01), and a higher incidence of PACU analgesic use (59% vs 7.5%, P <0.01). Patients in the SA group were able to drink and eat sooner than the GA group (83 +/- 23 vs 95 +/- 22 min, P <0.05 and 88 +/- 27 vs 105 +/- 29 min, P <0.01, respectively). The times to sit, walk, and void were similar. The length of PACU and ASU stay between the GA and SA groups were similar (67 +/- 17 vs 60 +/- 19 min, P >0.05 and 122 +/- 27 vs 127.9 +/- 31 min, P >0.05, respectively). The incidence of backache was higher in the SA group (35 vs 13.6%, P <0.05) than the GA group. However, the incidence of sore throat was higher in the GA compared to the SA group (25% vs 2.5%, P <0.01). CONCLUSIONS: SA with 50 mg of 1% lidocaine provides an improved recovery profile for ambulatory knee arthroscopy. Discharge times were similar, and with the exception of backache and sore throat, the incidence of complications was similar.     

Prilocaine or mepivacaine for combined sciatic-femoral nerve block in patients receiving elective knee arthroscopy

AIM: The aim of this study was to evaluate the onset time of surgical block, recovery of motor function and duration of post-operative analgesia of combined sciatic-femoral nerve block performed with either mepivacaine or prilocaine. METHODS: With Ethical Committee approval and written informed consent, 30 ASA physical status I-II patients, undergoing elective arthroscopic knee surgery, received a combined sciatic-femoral nerve block with 30 ml of either 2% mepivacaine (n=15) or 1% prilocaine (n=15). An independent observer recorded the onset time of sensory and motor blocks, the need for intraoperative analgesia supplementation, recovery of motor function, and first request of post-operative pain medication. RESULTS: Onset time of nerve block required 15+/-5 min with prilocaine and 12+/-7 min with mepivacaine (p=0.33). No patient required general anesthesia to complete surgery; 3 patients receiving prilocaine (20%) and 2 patients receiving mepivacaine (13%) required 0.1 mg fentanyl intravenously to complete surgery (p=0.99). Recovery of motor function and first request of post-operative pain medication occurred after 238+/-36 min and 259+/-31 min with prilocaine, and 220+/-48 min and 248+/-47 min with mepivacaine (p=0.257 and p=0.43, respectively). Patient satisfaction was good in all studied patients. CONCLUSION: Prilocaine 1% provides adequate sensory and motor block for arthroscopic knee surgery, with a clinical profile similar to that produced by 2% mepivacaine, and may be a good option for surgical procedures of intermediate duration and not associated with severe postoperative pain.