Spinal 2-chloroprocaine: the effect of added fentanyl

Chloroprocaine is being investigated as a possible replacement for spinal lidocaine. Adding fentanyl to lidocaine increases the quality of spinal anesthesia without prolongation of block. We report the characteristics of 2-chloroprocaine (2-CP) spinal anesthesia with or without fentanyl in 8 volunteers receiving 40 mg 2-CP with saline or 20 micro g fentanyl in a double-blinded, randomized, crossover manner. Spinal anesthesia was successful for all subjects with complete block regression, ambulation, and void by 110 min. Itching occurred in all subjects receiving fentanyl, though medication was not required. No subject reported signs of transient neurological symptoms. Peak block with fentanyl averaged T5 (T3-7) and without fentanyl T9 (L1-T4) (P = 0.005). Regression to L1 was 78 +/- 7 min with fentanyl and 53 +/- 19 min without fentanyl (P = 0.02). Tourniquet was tolerated for 51 +/- 8 min with fentanyl and for 34 +/- 14 min without fentanyl (P = 0.02). Complete regression of block occurred at 104 +/- 7 min with fentanyl and by 95 +/- 9 min without fentanyl (P = 0.02). We conclude that 2-CP spinal anesthesia provides rapid onset and adequate potency, giving it a positive profile for ambulatory surgery. The addition of fentanyl lengthens regression to L1 and tourniquet tolerance while minimally lengthening block duration. IMPLICATIONS: Spinal 2-chloroprocaine (40 mg) provides rapid onset and reliable blockade without signs of transient neurological symptoms, giving it a positive profile for ambulatory surgical settings. The addition of fentanyl appears to lengthen the regression to L1 dermatome and tourniquet time while minimally lengthening duration of block.     

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.     

Spinal 2-chloroprocaine for surgery: an initial 10-month experience

Spinal 2-chloroprocaine (2-CP) is currently being investigated as a short-acting alternative to lidocaine, which frequently causes transient neurologic symptoms (TNS) in surgical patients. TNS has not been reported with 2-CP in volunteers in doses ranging from 30 to 60 mg and appears to provide an excellent level of surgical anesthesia. In this retrospective study, we describe the experience with spinal 2-CP in surgical patients during its first 10 mo of clinical use at our institution. Most patients had ambulatory surgery, including 39 orthopedic, 30 general surgical, 18 gynecologic, and 34 genitourinary procedures. Chloroprocaine 30 or 40 mg, with or without fentanyl (10-20 microg), was the most common (92%) dose combination used. Mean peak block height averaged T6 to T8. The surgical procedure time was 32.3 +/- 18.4 min. Time from placement of the block to the end of the surgical procedure was 53.1 +/- 20.7 min. Times to ambulation and discharge were 155.1 +/- 34.7 min and 207.9 +/- 69.4 min, respectively. 2-CP spinal anesthesia has proven to be a safe and effective alternative to lidocaine and procaine for ambulatory surgical procedures of < or =1 h, with a predictable regression of block height. No patients reported TNS after surgery.     

Spinal 2-chloroprocaine: a comparison with small-dose bupivacaine in volunteers

Ambulatory surgery continues to increase nationwide. Because spinal lidocaine is associated with transient neurologic symptoms, many clinicians have switched to small-dose bupivacaine for outpatient spinal anesthesia. However, bupivacaine often produces inadequate surgical anesthesia and has an unpredictable duration. Preservative-free 2-chloroprocaine (2-CP) has reemerged as an alternative for outpatient spinal anesthesia. We designed this double-blind, randomized, crossover, volunteer study to compare 40 mg of 2-CP with small-dose (7.5 mg) bupivacaine with measures of pinprick anesthesia, motor strength, tolerance to tourniquet and electrical stimulation, and simulated discharge criteria. Peak block height (2-CP average T7 [range T3-10]; bupivacaine average T9 [range T4-L1]), regression to L1 (2-CP 64 +/- 10 versus bupivacaine 87 +/- 41 min), and tourniquet tolerance (2-CP 52 +/- 11 versus bupivacaine 60 +/- 27 min) did not differ between drugs (P = 0.15, 0.12, and 0.40, respectively). However, time to simulated discharge (including time to complete block regression, ambulation, and spontaneous voiding) was significantly longer with bupivacaine (2-CP 113 +/- 14, bupivacaine 191 +/- 30 min, P = 0.0009). No subjects reported transient neurologic symptoms or other side effects. We conclude that spinal 2-CP provides adequate duration and density of block for ambulatory surgical procedures, and has significantly faster resolution of block and return to ambulation compared with 7.5 mg of bupivacaine.     

Spinal 2-chloroprocaine: the effect of added clonidine

Preservative-free 2-chloroprocaine (2-CP) is being investigated for short-acting spinal anesthesia. Clonidine improves the quality of spinal bupivacaine and ropivacaine, but in traditional doses (1-2 microg/kg) it produces systemic side effects. It has not been studied in combination with 2-CP. In this double-blind, randomized crossover study, we compared spinal 2-CP (30 mg) with and without clonidine (15 microg) in eight volunteers. Pinprick anesthesia, motor strength, tolerance to electrical stimulation and thigh tourniquet, and time to ambulation were assessed. Peak block height was similar between 2-CP (T8 [range, T6 to L2]) and 2-CP with clonidine (T8 [range, T4 to T11]) (P = 0.57). Sensory anesthesia was prolonged with clonidine at L1 (51 +/- 23 min versus 76 +/- 11 min; P = 0.002), as was complete block regression (99 +/- 18 min versus 131 +/- 15 min; P = 0.001). Lower extremity motor blockade was increased with clonidine (return to baseline Bromage score: 65 +/- 13 min versus 79 +/- 19 min, P = 0.004; return to 90% gastrocnemius strength: P = 0.003). Clonidine increased tourniquet tolerance from 33 to 45 min (P = 0.06) and increased time to ambulation, spontaneous voiding, and discharge (99 +/- 18 min versus 131 +/- 15 min for all; P = 0.001). There were no differences in hemodynamic measurements, and no subject reported transient neurologic symptoms. We conclude that small-dose clonidine increases the duration and improves the quality of 2-CP spinal anesthesia without systemic side effects.     

Spinal 2-chloroprocaine: a comparison with procaine in volunteers

Recent studies using preservative-free 2-chloroprocaine (2-CP) for spinal anesthesia have shown it to be a reliable short-acting drug that provides similar anesthesia to lidocaine. In this randomized, double-blind, crossover study, we compared the characteristics of spinal 2-CP (30 mg) with those of procaine (80 mg) in eight volunteers to determine whether either drug produces spinal anesthetic characteristics ideal for outpatient surgery. By using sensation to pinprick, transcutaneous electrical stimulation, tolerance to thigh tourniquet, and motor blockade as surrogates for surgical efficacy, 2-CP compared similarly to procaine. Peak block height (T9 [range, T6 to T12] versus T6 [T4 to T8]; P = 0.0796), time to two-segment regression (51 +/- 17 min versus 53 +/- 10 min; P = 0.7434), tourniquet time tolerance (37 +/- 16 versus 49 min +/- 17 min; P = 0.1755), and time to return of motor strength (Bromage scale: 54 +/- 23 min versus 55 +/- 44 min, P = 0.9366; return of 90% quadriceps strength: 78 +/- 9 min versus 98 +/- 30 min; P = 0.0721) were all similar. Procaine did produce overall longer sensory blockade (P = 0.0011) and motor blockade at the gastrocnemius (P = 0.0004) and quadriceps (P = 0.0146) muscles. Times until the resolution of sensory blockade (103 +/- 12 min versus 151 +/- 26 min; P = 0.0003), ambulation (103 +/- 12 min versus 151 +/- 26 min; P = 0.0003), and micturition (103 +/- 12 min versus 156 +/- 23 min; P < 0.0001) were all prolonged after procaine. In conclusion, at the doses tested, spinal 2-CP (30 mg) may be a better choice for short outpatient procedures because it provides anesthesia with similar efficacy as procaine (80 mg) but with more rapid fulfillment of discharge criteria.     

Spinal 2-chloroprocaine: minimum effective dose

BACKGROUND AND OBJECTIVES: Recent studies using preservative-free 2-chloroprocaine (2-CP) for spinal anesthesia have shown it to be a reliable short-acting agent in the 30-mg to 60-mg range. Investigations of doses below this range have not been performed. METHODS: To establish the minimum effective dose for spinal anesthesia, this randomized, double-blind, crossover study investigates the characteristics of spinal 2-CP 10 mg and 20 mg in 8 volunteers and compares the results with previous data obtained for 30 to 60 mg in the same human model. RESULTS: Peak block height, regression to L1, tolerance to tourniquet, and transcutaneous electrical stimulation all increased with increasing doses from 10 to 60 mg ( P <.0001). Likewise, time to complete block regression, ambulation, and micturition also increased with increasing spinal 2-CP dosage ( P <.0001). Degree of motor block generally increased with increasing doses from 10 to 60 mg; however, no differences existed between the 20-mg and 30-mg and between the 40-mg and 60-mg doses. CONCLUSIONS: Spinal 2-CP 40 mg and 60 mg provide rapid and reliable sensory and motor block. Although the 20-mg and 30-mg doses can produce sensory anesthesia adequate for brief surgical procedures, less motor block and some sacral sparing should be anticipated. Because the 10-mg dose produces only brief and inconsistent sensory anesthesia, it can be considered a no-effect dose.     

Spinal 2-chloroprocaine: a dose-ranging study and the effect of added epinephrine

With the availability of preservative- and antioxidant-free 2-chloroprocaine (2-CP), there may be an acceptable short-acting alternative to lidocaine for spinal anesthesia. We examined the safety, dose-response characteristics, and effects of epinephrine with spinal 2-CP. Six volunteers per group were randomized to receive 30, 45, or 60 mg of spinal 2-CP with and without epinephrine. Intensity and duration of sensory and motor blockade were assessed. When 11 of the 18 volunteers complained of vague, nonspecific flu-like symptoms, breaking of the blind revealed that all spinal anesthetics associated with the flu-like symptoms contained epinephrine. There were no complaints of flu-like symptoms in the volunteers who received 2-CP without epinephrine. No further spinal anesthetics containing epinephrine were administered, resulting in 29 anesthetics (11 with epinephrine, 18 without epinephrine.) Plain 2-CP demonstrated a dose-dependent increase in peak block height and duration of effect at all variables except time to 2-segment regression and time to regression to T10. Time to complete sensory regression with plain 2-CP was 98 +/- 20, 116 +/- 15, and 132 +/- 23 min, respectively. 2-CP with epinephrine produced times to complete sensory regression of 153 +/- 25, 162 +/- 33, and 148 +/- 29 min, respectively. Preservative and antioxidant free 2-CP can be used effectively for spinal anesthesia in doses of 30-60 mg. Epinephrine is not recommended as an adjunct because of the frequent incidence of side effects. IMPLICATIONS: Hyperbaric spinal 2-chloroprocaine is effective and has an anesthetic profile appropriate for use in the surgical outpatient over the dose range of 30-60 mg without signs of transient neurologic symptoms. The addition of epinephrine is not recommended because of the frequent incidence of side effects.     

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.     

Dose response relationships for isobaric spinal mepivacaine using the combined spinal epidural technique.

Mepivacaine, a local anesthetic with similar physiochemical properties to those of lidocaine, is an adequate alternative for patients undergoing ambulatory procedures, and is associated with a lower incidence of transient neurologic symptoms (TNS) than lidocaine. We studied the dose-response characteristics of isobaric intrathecal mepivacaine using the combined spinal epidural technique for patients undergoing ambulatory arthroscopic surgery of the knee. Seventy-five patients were randomized prospectively to receive one of three doses of isobaric mepivacaine for spinal anesthesia: 30 mg (2 mL 1.5%), 45 mg (3 mL 1.5%), or 60 mg (4 mL 1.5%). An observer, blinded to the dose, recorded sensory level to pinprick and motor response until resolution of the block. In addition, the incidence of TNS was determined. An initial intrathecal dose of 30 mg of isobaric mepivacaine 1.5% produced satisfactory anesthesia in 72% of ambulatory surgical patients undergoing unilateral knee arthroscopy with a significantly shorter duration of sensory (158 +/- 32 min) and motor blockade (116 +/- 38 min) than doses of 45 and 60 mg. An intrathecal dose of 45 mg produced satisfactory anesthesia in all patients with a shorter duration of sensory (182 +/-38 min) and motor blockade (142 +/- 37 min) than 60 mg of mepivacaine 1.5% (203 +/- 36 min and 168 +/- 36 min, respectively). The incidence of TNS was 7.4% overall (1.2%-13.6% confidence intervals), less than the rates previously reported after spinal anesthesia with lidocaine in ambulatory surgical patients undergoing knee arthroscopy. We conclude that mepivacaine can be used as an adequate alternative to lidocaine for ambulatory procedures. IMPLICATIONS: This study evaluated the postoperative duration of spinal anesthesia after varying doses of isobaric mepivacaine and the incidence of transient radiating back and leg pain. We found that 45 mg of mepivacaine provided adequate anesthesia, a timely discharge, and a lower incidence of back pain than that previously reported after lidocaine spinals.     

Spinal chloroprocaine solutions: density at 37 degrees C and pH titration

The density and pH of a local anesthetic are important characteristics in its use as an intrathecal drug. Preservative- and antioxidant-free formulations of chloroprocaine are available and are being investigated for short-duration spinal anesthesia. In this study, we evaluated the pH and density (to 5 significant digits in g/mL, at 37.0 degrees C) of these new chloroprocaine formulations. In addition to plain 2% and 3% chloroprocaine and 2% lidocaine, mixed solutions of 2% chloroprocaine with epinephrine or with bicarbonate were evaluated. Density was also measured after water dilution and after increasing amounts of added dextrose. Chloroprocaine, 2% or 3%, is hyperbaric relative to cerebrospinal fluid (CSF) before any addition of dextrose (density 1.00123 g/mL and 1.00257 g/mL, respectively). When diluted with water, all the solutions are hypobaric relative to CSF (density <1.00028 g/mL). Plain 2% lidocaine is the only dextrose-free solution measured to be hypobaric (density 1.00004 g/mL). Bisulfite-free 2-chloroprocaine remains very acidic (pH <4.0), but the pH can be increased to more than 7.0 with a small amount of bicarbonate (0.25-0.33 mL/10 mL). The increased density of plain chloroprocaine makes it a useful hyperbaric spinal drug without the addition of dextrose. IMPLICATIONS: Dextrose-free 2-chloroprocaine is hyperbaric relative to cerebrospinal fluid at 37 degrees C, and therefore can be used for spinal anesthesia without dextrose. Bisulfite-free 2-chloroprocaine remains very acidic (pH <4.0). The pH can be increased to more than 7.0 with a small amount of bicarbonate (0.25-0.33 mL/10 mL).     

Comparison between spinal anaesthesia and sciatic-femoral block for arthroscopic knee surgery

AIM: We compared spinal anesthesia and sciatic-femoral block for arthroscopic knee surgery in terms of hemodynamic changes, intraoperative anesthesia, postoperative analgesia, postoperative motor block and bladder function, side effects, and patient satisfaction. METHODS: Thirty-two patients were randomised into 2 groups: Group B (sciatic-femoral block with mepivacaine 1% 15 + 25 mL, 120 mm/35 mm 22-gauge needles and ElectroNerve Stimulator) and Group S (unilateral spinal anesthesia with 7 mg of hyperbaric bupivacaine 0.5% and 25-gauge Sprotte needle in L2-L3 space). We recorded pain, together with hemodynamic parameters (baseline, 5, 10, 15, 30 min), utilising Numerical Rating Scale (NRS) during the tourniquet application and during the surgical procedures, anesthesia quality, orthopedic evaluation for intraoperative liberty of knee movement. During the postoperative period we recorded at 2, 4 and 6 h: postoperative analgesia, motor block, first urine output, side effects, first requirement for analgesic drug, patient satisfaction and costs. RESULTS: The only significant differences between the 2 groups (P<0.05) were the heart rate changes at 10, 15, 30 min with an increase in Group B and a decrease in Group S, and the first urine output at 200+/-69 min in Group B versus 269+/-66 min in Group S. CONCLUSION: In conclusion the sciatic-femoral nerve block is a valid alternative to spinal anesthesia for arthroscopic knee surgery, leading to a faster discharging from the hospital.     

Epidural morphine delays the onset of tourniquet pain during epidural lidocaine anesthesia

We conducted a randomized, double-blinded study to examine the onset time of tourniquet pain during epidural lidocaine anesthesia either with or without morphine in the epidural solution. Forty-five patients undergoing knee surgery with a thigh tourniquet were randomly allocated into 3 groups of 15 patients each: epidural morphine (EM; epidural administration of 17 mL of 2% lidocaine plus 2 mg of morphine, followed by IV injection of 0.2 mL of normal saline), IV morphine (IVM; 17 mL of 2% lidocaine plus 0.2 mL of normal saline, followed by IVM 2 mg IV), and control (17 mL of 2% lidocaine plus 0.2 mL of normal saline, followed by 0.2 mL of normal saline IV). The onset time of tourniquet pain was recorded. The level of sensory block was determined by the pinprick method at the occurrence of tourniquet pain. Hemodynamic changes and side effects of EM were also recorded. The onset time of tourniquet pain from both the epidural injection and the tourniquet inflation were significantly longer in the EM group (103 +/- 15 min and 80 +/- 15 min, respectively) compared with the IVM group (74 +/- 12 min and 50 +/- 12 min, respectively; P < 0.05) and the Control group (67 +/- 9 min and 45 +/- 9 min, respectively; P < 0.05). The level of sensory block at the onset of tourniquet pain and hemodynamic changes were not different among the three groups. Only two and three patients in the EM group complained of nausea/vomiting and pruritus, respectively. Respiratory depression was not observed in any patient. We conclude that epidural injection of the mixture of 2 mg of morphine and 2% lidocaine solution delayed the onset of tourniquet pain during epidural lidocaine anesthesia without significant morphine-related side effects. IMPLICATIONS: We examined the effect of epidural morphine on the onset of tourniquet pain during epidural lidocaine anesthesia. We found that the addition of 2 mg of morphine to epidural 2% lidocaine significantly delayed the onset of tourniquet pain without increasing morphine-related side effects.     

A comparison of spinal, epidural, and general anesthesia for outpatient knee arthroscopy

We compared general, epidural, and spinal anesthesia for outpatient knee arthroscopy (excluding anterior cruciate ligament repairs). Forty-eight patients (ASA physical status I-III) were randomized to receive either propofol-nitrous oxide general anesthesia with a laryngeal mask airway with anesthetic depth titrated to a bispectral index level of 40-60, 15-20 mL of 3% 2-chloroprocaine epidural, or 75 mg of subarachnoid procaine with 20 microg fentanyl. All patients were premedicated with <0.035 mg/kg midazolam and <1 microg/kg fentanyl and received intraarticular bupivacaine and 15-30 mg of IV ketorolac during the procedure. Recovery times, operating room turnover times, and patient satisfaction were recorded by an observer using an objective scale for recovery assessment and a verbal rating scale for satisfaction. Statistical analysis was performed with analysis of variance and chi(2). Postanesthesia care unit discharge times for the general and epidural groups were similar (general = 104+/-31 min, epidural = 92+/-18 min), whereas the spinal group had a longer recovery time (146+/-52 min) (P = 0.0003). Patient satisfaction was equally good in all three groups (P = 0.34). Room turnover times did not differ among groups (P = 0.16). There were no anesthetic failures or serious adverse events in any group. Pruritus was more frequent in the spinal group (7 of 16 required treatment) than in the general or epidural groups (no pruritus) (P<0.001). We conclude that epidural anesthesia with 2-chloroprocaine provides comparable recovery and discharge times to general anesthesia provided with propofol and nitrous oxide. Spinal anesthesia with procaine and fentanyl is an effective alternative and is associated with a longer discharge time and increased side effects. Implications: For outpatient knee arthroscopy, anesthesia can be provided adequately with regional or general anesthesia. Epidural and general anesthesia provide equal recovery times and patient satisfaction, whereas spinal anesthesia may prolong recovery and have increased side effects. The choice of anesthesia may depend primarily on the patient's interest in being alert or asleep during the procedure.     

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.     

Combined spinal-epidural anesthesia using epidural volume extension leads to faster motor recovery after elective cesarean delivery: a prospective, randomized, double-blind study

Epidural volume extension (EVE) via a combined spinal-epidural (CSE) technique is the enhancement of a small-dose intrathecal block by epidural saline boluses. In this prospective, randomized, double-blind study, we compared the EVE technique with single-shot spinal anesthesia with respect to its sensory and motor block profile and hemodynamic stability. Sixty-two parturients (n = 31 in each group) undergoing elective cesarean deliveries were administered either spinal anesthesia with hyperbaric 0.5% bupivacaine 9 mg and fentanyl 10 microg or CSE comprising intrathecal hyperbaric 0.5% bupivacaine 5 mg with fentanyl 10 microg, followed by 0.9% saline 6.0 mL through the epidural catheter 5 min thereafter. In each group, the lowest systolic blood pressure (SBP), sensory block level to loss of pain from pinprick, and modified Bromage scores were recorded at 2.5-min intervals. The visual analog pain score (VAS), peak sensory block height, highest modified Bromage motor score, time for sensory regression to the tenth thoracic dermatome (T10), and motor block recovery were compared between groups. Both groups were comparable in demographic data, VAS scores, peak sensory block height, time for sensory regression to T10, and lowest SBP recorded. Patients in the EVE group demonstrated significantly faster motor recovery to modified Bromage 0 (73 +/- 33 min versus 136 +/- 32 min, P < 0.05). IMPLICATIONS: When compared with conventional, single-shot spinal anesthesia, epidural volume extension of a small-dose spinal block provides satisfactory anesthesia for cesarean delivery with only 55% of the bupivacaine dose required and is associated with faster motor recovery of the lower limbs.     

Spinal 2-chloroprocaine: effective dose for ambulatory surgery

Background: There is an interest in finding a safe, short-acting spinal anaesthetic, suitable for ambulatory surgery. In this prospective study, we evaluated the effective dose of plain 2-chloroprocaine (2-CP) for lower limb surgery, including knee arthroscopy and saphenectomy.
Methods: Sixty-four ASA physical status I–III patients undergoing elective lower limb surgery were randomly allocated to one of the four local anaesthetic groups for spinal anaesthesia in a double-blind manner. The patients ( n =16 patients in each group) received 35, 40, 45 or 50 mg of 10 mg/ml isobaric 2-CP.
Results: In all patients, anaesthesia was sufficient for the planned surgery. The median peak block height (T9) was similar in all four groups ( P =0.66). Time to complete sensory block regression was faster in the 35 mg group (111 min, mean) and in the 40 mg group (108 min) than in the 50 mg group (134 min, P =0.005). No differences in time to complete motor block regression were observed ( P =0.3). Home discharge time was faster in the 35 mg group (123 min) and in the 40 mg group (122 min) than in the 50 mg group (165 min, P =0.001). No complications related to spinal anaesthesia were observed and no transient neurologic symptoms (TNS) were reported at the 3-day follow-up.
Conclusion: Spinal 2-CP, 10 mg/ml 35, 40, 45 and 50 mg provide reliable sensory and motor block for ambulatory surgery, while reducing the dose of 2-CP to 35 and 40 mg resulted in a spinal block of faster ambulation.     

Hyperbaric spinal ropivacaine: a comparison to bupivacaine in volunteers

BACKGROUND: Ropivacaine is a newly introduced local anesthetic that may be a useful alternative to low-dose bupivacaine for outpatient spinal anesthesia. However, its relative potency to bupivacaine and its dose-response characteristics are unknown. This double-blind, randomized, crossover study was designed to determine relative potencies of low-dose hyperbaric spinal ropivacaine and bupivacaine and to assess the suitability of spinal ropivacaine for outpatient anesthesia. METHODS: Eighteen healthy volunteers were randomized into three equal groups to receive one spinal administration with bupivacaine and a second with ropivacaine, of equal-milligram doses (4, 8, or 12 mg) of 0.25% drug with 5% dextrose. The duration of blockade was assessed with (1) pinprick, (2) transcutaneous electrical stimulation, (3) tolerance to high tourniquet, (4) electromyography and isometric force dynamometry, and (5) achievement of discharge criteria. Differences between ropivacaine and bupivacaine were assessed with linear and multiple regression. P < 0.05 was considered significant. RESULTS: Ropivacaine and bupivacaine provided dose-dependent prolongation of sensory and motor block and time until achievement of discharge criteria (R2 ranges from 0.33-0.99; P values from < 0.001 through 0.01). Spinal anesthesia with ropivacaine was significantly different from bupivacaine and was approximately half as potent for all criteria studied. A high incidence of back pain (28%; P = 0.098) was noted after intrathecal ropivacaine was given. CONCLUSION: Ropivacaine is half as potent and in equipotent doses has a similar profile to bupivacaine with a higher incidence of side effects. Low-dose hyperbaric spinal ropivacaine does not appear to offer an advantage over bupivacaine for use in outpatient anesthesia.     

Hyperbaric Spinal Ropivacaine: A Comparison to Bupivacaine in Volunteers

Background: Ropivacaine is a newly introduced local anesthetic that may be a useful alternative to low-dose bupivacaine for outpatient spinal anesthesia. However, its relative potency to bupivacaine and its dose-response characteristics are unknown. This double-blind, randomized, crossover study was designed to determine relative potencies of low-dose hyperbaric spinal ropivacaine and bupivacaine and to assess the suitability of spinal ropivacaine for outpatient anesthesia.

Methods: Eighteen healthy volunteers were randomized into three equal groups to receive one spinal administration with bupivacaine and a second with ropivacaine, of equal-milligram doses (4, 8, or 12 mg) of 0.25% drug with 5% dextrose. The duration of blockade was assessed with (1) pinprick, (2) transcutaneous electrical stimulation, (3) tolerance to high tourniquet, (4) electromyography and isometric force dynamometry, and (5) achievement of discharge criteria. Differences between ropivacaine and bupivacaine were assessed with linear and multiple regression. P < 0.05 was considered significant.

Results: Ropivacaine and bupivacaine provided dose-dependent prolongation of sensory and motor block and time until achievement of discharge criteria (R2 ranges from 0.33-0.99; P values from < 0.001 through 0.01). Spinal anesthesia with ropivacaine was significantly different from bupivacaine and was approximately half as potent for all criteria studied. A high incidence of back pain (28%; P = 0.098) was noted after intrathecal ropivacaine was given.