Ropivacaine 0.2% versus bupivacaine 0.1% with fentanyl: a double blind comparison for analgesia during labour

We have performed a randomized, double-blind comparison of twoepidural drug regimens for analgesia in labour. In the bupivacainegroup (BUPIV), 101 healthy parturients received 0.1% bupivacainewith fentanyl 2 µg ml^–1. In the ropivacaine group(ROPIV), 102 women received 0.2% ropivacaine. Both groups receivedan initial loading dose of 15 ml, a continuous infusion of 8ml h^–1, and top-ups of 10 ml. Breakthrough pain not respondingto a routine top-up was treated with an ‘escape’top-up of 10 ml 0.25% bupivacaine. The two groups were comparedfor complete analgesia at 30 min, routine and ‘escape’top-up requirements, midwife assessment of analgesic efficacy,delivery mode, patient visual analogue scores (VAS) for firstand second stage analgesia, overall satisfaction, and patientassessment of motor blockade. Patients receiving ropivacainereceived fewer routine top-ups (median 1.0 vs. 2.0, P=0.001)and fewer escape top-ups (9.8% vs. 21.8%, P=0.02). The ropivacainegroup was more likely to be pain free in the first stage (51%vs. 33.7%, P=0.01). There were no significant differences inpatients’ assessment of motor block or mode of deliverybetween the groups. Pain relief and satisfaction scores frommidwives and patients were consistently better in the ropivacainegroup, but did not reach statistical significance. Br J Anaesth 2000; 85: 826–9     

Transient neurological symptoms after spinal anaesthesia with 4% mepivacaine and 0.5% bupivacaine

Several studies have reported transient neurological symptoms after spinal anaesthesia with 5% lignocaine. In order to evaluate the role of concentrated solutions of local anaesthetic in the development of transient neurological symptoms, 200 ASA I or II patients undergoing minor orthopaedic or rectal surgery under spinal anaesthesia were allocated randomly to receive 4% mepivacaine 80 mg or hyperbaric 0.5% bupivacaine 10 mg. All patients were interviewed by an anaesthetist approximately 24 h after spinal anaesthesia, and after 1 week patients were asked to return a written questionnaire. The incidence of transient neurological symptoms consisting of pain in the buttocks or pain radiating symmetrically to the lower extremities differed (P < 0.001) between patients receiving mepivacaine (30%) and those receiving bupivacaine (3%). Hyperbaric 0.5% bupivacaine can be recommended for minor operations on the lower abdomen or lower extremities.      

Epidural anesthesia with bupivacaine 0.75% in comparison with bupivacaine 0.5% and mepivacaine 1.5% with adrenaline (author's transl)

147 patients undergoing low laparotomies, perineal operations and operations on the lower limbs were given bupivacaine 0.75%, bupivacaine 0.5% or mepivacain-adrenaline 1.5% for epidural anaesthesia. The anaesthesia was most effective after bupivacaine 0.75%. In this group the intensity and duration of both sensory analgesia and motor block were more prolonged. No serious complications occurred. No increase in toxicity, when using bupivacaine 0.75% (total dose of 128 mg) for epidural anaesthesia, has been shown in this clinical trial.     

Comparison of two fentanyl doses to improve epidural anaesthesia with 0.5% bupivacaine for caesarean section

Ninety women undergoing elective caesarean section under epidural anaesthesia were double blindly randomised into three groups to receive either 2 ml of saline or 50 or 100 μg of fentanyl in 2 ml volume added to 0.5% bupivacaine. Both doses of fentanyl intensified the epidural anaesthesia and reduced patient discomfort during the operation. In both fentanyl groups the epidural blockade more often reached the 5th thoracic segment (P = 0.0258), the patients had significantly less pain (P = 0.0256), needed less intravenous diazepam medication during the operation (P = 0.0005) and the operating conditions were better when compared to the saline group (P = 0.0416). There was no difference between the groups in the condition of the neonates as assessed by the Apgar score and cord blood pH. The postoperative time until treatment for pain was requested by the patients was more than 1 h longer in the fentanyl groups, but there was no difference in the total amount of postoperative analgesics needed during the first 24 h when compared to the saline group. Mild pruritus not requiring treatment was more common in fentanyl groups than in the saline group (P = 0.0187). The results suggest that 50 μg of fentanyl added to 0.5% bupivacaine increases patient comfort and improves the quality of epidural anaesthesia for caesarean section, and that adding 100 μg does not give further advantage.     

Motor blockade and EMG recordings in epidural anaesthesia. A comparison between mepivacaine 2%, bupivacaine 0.5 % and etidocaine 1.5%

In a double-blind study young volunteers randomly received 20 ml of mepivacaine 2%, bupivacaine 0.5% or etidocaine 1.5% epidurally, all solutions with adrenaline. The mean cephalad spread of pin-prick analgesia was equal (T10) in the groups, but the duration was longest for bupivacaine and etidocaine. The motor blockade of the rectus abdominis muscles was assessed quantitatively by rectified integrated electromyographic recordings (RIEMG) and as number of turns in EMG recordings [changes in the direction (rise/fall) of the EMG; TURNS] from three different segmental levels, T7, T9 and T11. The motor blockade of the quadriceps muscles was estimated by EMG recordings simultaneously with muscle force measurements at maximal isometric knee extension. Motor blockade was also evaluated by the Bromage scale. There was good correlation (correlation coefficient 0.91) between RIEMG values and muscle force in knee extension during epidural anaesthesia. TURNS showed a non-linear relationship to isometric force during epidural anaesthesia and added no further information. At the lower parts of the abdomen (T11), etidocaine gave more profound and longer motor blockade than mepivacaine. For quadriceps muscle function, motor blockade was almost complete with all three local anaesthetics; the duration of maximum motor blockade was short (45-60 min) for mepivacaine, but about 5 h with etidocaine. At the time when the Bromage scale indicated complete regression of motor blockade, the muscle force of knee extension was only 30% and the quadriceps RIEMG 35% of control values and 1-3 h remained until the time of mobilization.(ABSTRACT TRUNCATED AT 250 WORDS)     

A comparison of epidural ropivacaine 0.75% and bupivacaine 0.5% with fentanyl for elective caesarean section

BACKGROUND: Early studies suggested that ropivacaine had clinical advantages over bupivacaine with respect to cardiotoxicity and motor block, and that it was suitable for epidural caesarean section. This study was set up to compare epidural 0.75% ropivacaine with a popular bupivacaine/fentanyl mixture for elective caesarean section. METHODS: Eighty women having elective caesarean section under epidural anaesthesia were randomly allocated to receive 20 mL of either 0.75% ropivacaine or 0.5% bupivacaine plus fentanyl 100 microg. Supplementation with 2% plain lidocaine was used where necessary. Times were recorded for onset of sensory block, density and duration of motor block, and the need for supplementation. RESULTS: There was no difference between the groups in the time (mean [SD]) to achieve sensory blockade to cold to T4 (ropivacaine 15.8 [5.6] min, bupivacaine/fentanyl 18.7 [9.1] min, P=0.13) or to S1 (ropivacaine 18.3 [4.6] min, bupivacaine/fentanyl 17.4 [7.6] min, P=0.59), or in the need for supplementation. However, ropivacaine produced a motor block that was denser (median Bromage score ropivacaine 3, bupivacaine/fentanyl 1.5, P=0.0041), and of longer duration (ropivacaine 237 [84] min, bupivacaine/fentanyl 144 [76] min, P<0.0001). CONCLUSIONS: This study suggests that epidural 0.75% ropivacaine without opioid may be used as an alternative to bupivacaine 0.5% with fentanyl for elective caesarean section, but it does not induce anaesthesia any faster and may result in a denser, more prolonged, motor block.     

Spinal anaesthesia using hyperbaric 0.75% vs hyperbaric 1% bupivacaine: a double blind comparison

AIM: The aim of this study was to compare the anesthetic effects, potency and postoperative outcome of 0.75% and 1% concentrations of hyperbaric bupivacaine in selective spinal anesthesia. METHODS: We enrolled 40 patients in a double blind fashion in 2 groups (A= 0.75% bupivacaine; B= 1% bupivacaine). Demographic data were respectively for Groups A and B: age 40.6+/-16 and 67+/-16, weight 74+/-14.4 and 68+/-10.2; sex 10M/10F and 6M/14F; ASA I-II 11/9 and 14/6. All patients received 11.25 mg bupivacaine. In all cases a 27G Whitacre needle was introduced at L1-L2, L2- L3, L3-L4 introduced with a midline approach. Time to onset and offset of sensitive and motor block, dermatomeric extension non invasive blood pressure, heart rate, ephedrine dose, deambulation time, diuresis time and request for supplemental analgesia were recorded. RESULTS: No statistically significant differences between the 2 groups for demographic data were found. Group B revealed a faster onset and a more adequate dermatomeric extension (4.1+/-0.8 min vs 6.5+/-1.2 min). Both concentrations guaranteed good hemodynamic stability. Motor offset times were 115.8+/-145 min and 142+/-4.8 min respectively in groups A and B. Sensitive offset times were 197.5+/-12 min and 168+/-5.2 min respectively in groups A and B. No statistically relevant differences were noticed for intraoperative Bromage, sensitive block or for postoperative motor and sensitive offset time, diuresis time and deambulation time. There are no advantages of 1% hyperbaric bupivacaine over 0.75% for selective spinal anesthesia, while several disadvantages presented shorter duration of postoperative analgesia and higher incidence of headache.     

Interscalene brachial plexus anaesthesia with 0.5%, 0.75% or 1% ropivacaine: a double-blind comparison with 2% mepivacaine

We have compared interscalene brachial plexus block performed with ropivacaine or mepivacaine in 60 healthy patients undergoing elective shoulder surgery. Patients were allocated randomly to receive interscalene brachial plexus anaesthesia with 20 ml of 0.5% ropivacaine (n = 15), 0.75% ropivacaine (n = 15), 1% ropivacaine (n = 15) or 2% mepivacaine (n = 15). Readiness for surgery (loss of pinprick sensation from C4 to C7 and inability to elevate the limb from the bed) was achieved sooner with 1% ropivacaine (mean 10 (SD 5) min) than with 0.5% ropivacaine (22 (7) min) (P < 0.001) or 2% mepivacaine (18 (9) min) (P < 0.02). Postoperative analgesia was similar with the three ropivacaine concentrations (11.5 (5) h, 10.7 (2) h and 10 (2.4) h with 0.5%, 0.75% and 1% concentrations, respectively) and nearly two-fold longer compared with 2% mepivacaine (5.1 (2.7) h) (P < 0.001).      

Extradural analgesia with clonidine and fentanyl compared with 0.25% bupivacaine in the first stage of labour

Conventional extradural analgesia during labour with 0.25-0.375% bupivacaine may induce motor weakness and subjective sensory deficit, reducing maternal satisfaction. Even in a regimen for ambulatory extradural analgesia (0.1% bupivacaine-fentanyl 2 micrograms ml-1), a potential for proprioreception impairment exists, which may impair safe ambulation. We have combined fentanyl with clonidine for extradural analgesia in labour, and compared its effects with 0.25% bupivacaine, in a randomized, double-blind study. We studied 28 women requesting extradural analgesia for labour; they were allocated randomly to either group 1, who received clonidine 120 micrograms with fentanyl 50 micrograms, or group 2, who received bupivacaine 25 mg. Detailed clinical neurological examination was undertaken 30 min later. Pain was assessed subjectively using a 10-cm visual analogue scale (VAS). There were no significant differences in VAS between the groups at any time. Median onset of analgesia was longer in group 1 (24.3 (interquartile range 20-35) compared with 17.5 (15-25) min) (P < 0.05) and 79% of group 1 vs 86% of group 2 patients reported a high degree of satisfaction with extradural analgesia. Patients in group 2 had a much higher incidence of motor weakness (P < 0.01), impaired perception of pinprick (P < 0.01) and impaired distal joint proprioception (P < 0.05) than group 1. We conclude that clonidine 120 micrograms-fentanyl 50 micrograms provided comparable extradural analgesic efficacy as 0.25% bupivacaine for the first stage of labour. Furthermore, unwanted neurological effects were significantly less.      

Spinal anaesthesia for transurethral surgery: comparison of 2% lignocaine with hyperbaric 0.5% bupivacaine

We have compared 2% lignocaine 3.5 ml with 0.5% hyperbaric bupivacaine 3 ml in a randomized, double-blind study in 30 patients undergoing subarachnoid anaesthesia for transurethral surgery. A sensory level of T10 was produced more quickly (P = 0.0001) and maximum height reached sooner (P = 0.0002) with lignocaine, although there was a greater reduction in systolic arterial pressure (P = 0.03) and a trend towards slower heart rates (P = 0.056). Return of full sensory and motor function occurred earlier with lignocaine (P = 0.00005 and P = 0.02).      

Postoperative analgesia after major abdominal surgery: Fentanyl–bupivacaine patient controlled epidural analgesia versus fentanyl patient controlled intravenous analgesia

BackgroundMajor abdominal surgeries induce neurohumoral changes responsible for postoperative pain, various organ dysfunctions and prolonged hospitalization. Inadequate pain control is harmful and costly to patients thus an appropriate pain therapy to those patients must be applicated.MethodsOne hundred patients (ASA I or II) of either sex aged from 20 to 60 years were scheduled for elective major abdominal surgery. Patients were allocated randomly into two groups (fifty patients each) to receive: patient-controlled epidural analgesia with bupivacaine 0.125% and fentanyl (PCEA group), or patient controlled intravenous analgesia with fentanyl (PCIA group). Postoperative pain was assessed over 24 h using Numerical Pain Rating scale (NPRS). The frequency of rescue analgesia, sedation score and overall patient satisfaction were recorded. Any concomitant events like nausea; vomiting, shivering, pruritus or respiratory complications were recorded postoperatively.ResultsThere was a significant less pain in PCEA group at 2, 8 and 12 h. postoperative but PCIA group had less pain at immediate postoperative time. As regard sedation scale, patients of the PCEA group were significantly less sedated than PCIA group at immediate postoperative only. Overall patient satisfaction was significantly more in PCEA group.ConclusionThis study concluded that both PCEA and PCIA were effective in pain relief after major abdominal surgery but PCEA was much better in pain relief, less sedating effect and overall patient satisfaction.     

0.75% and 0.5% ropivacaine for axillary brachial plexus block: a clinical comparison with 0.5% bupivacaine

BACKGROUND AND OBJECTIVES: Although ropivacaine has been extensively studied for epidural anesthesia, very few reports exist on brachial plexus block. We therefore decided to investigate the clinical features of axillary brachial plexus anesthesia with two different concentrations of ropivacaine (0.5% and 0.75%) and to compare the results with those obtained with 0.5% bupivacaine. METHODS: Three groups of patients were randomized and prospectively studied. They received, in a double-blind fashion, 32 mL of the local anesthetic solution into the midaxilla, by a nerve-stimulator technique. Onset time in each of the stimulated nerves was recorded both for the sensory and motor block. Peak time (ready to surgery), rate of supplemental blocks, need for intraoperative opioids, duration of sensory and motor block, postoperative analgesic requirements, and patient satisfaction were also recorded. RESULTS: The rate of complete sensory and motor block observed with both ropivacaine groups was higher at 10, 15, and 20 minutes postinjection (P < .001). The mean peak time was shorter with ropivacaine than with bupivacaine (R50 = 16.37 minutes, R75 = 14.7 minutes, B = 22.3 minutes, P < .05). The quality of the anesthesia was higher with ropivacaine, as measured by the intraoperative needs for opioids and the overall patient's satisfaction (P < .05). No significant differences were noted with all the other studied parameters. CONCLUSION: Ropivacaine showed advantages over bupivacaine for axillary brachial plexus block. Because no statistical differences were found between the two ropivacaine groups, we therefore conclude that 0.75% does not add benefit and that 0.5% ropivacaine should be used to perform axillary brachial plexus blocks.     

Pulmonary function changes after interscalene brachial plexus anesthesia with 0.5% and 0.75% ropivacaine: a double-blinded comparison with 2% mepivacaine

The purpose of this investigation was to compare, in a prospective, double-blinded fashion, 0.5% and 0.75% ropivacaine with 2% mepivacaine to determine their effects on respiratory function during interscalene brachial plexus (IBP) anesthesia. With ethical committee approval and written, informed consent, 30 healthy patients presenting for elective shoulder capsuloplastic or acromioplastic procedures were randomized to receive IBP anesthesia by 20 mL of either 0.5% ropivacaine (n = 10), 0.75% ropivacaine (n = 10), or 2% mepivacaine (n = 10). Block onset time, pulmonary function variables, ipsilateral hemidiaphragmatic motion (ultrasonographic evaluation), and first requirement of postoperative analgesic were evaluated. Surgical anesthesia (loss of pinprick sensation from C4 to C7 and motor block of the shoulder joint) was achieved later with 0.5% ropivacaine than with either 0.75% ropivacaine or 2% mepivacaine (P < 0.05), whereas the first pain medication was requested later with both ropivacaine concentrations than with mepivacaine (P < 0.0005). No differences in quality of the block or patient acceptance were observed in the three groups. All 30 patients had ipsilateral hemidiaphragmatic paresis and large mean decreases in forced vital capacity (ropivacaine 0.5%: 40% +/- 17%, ropivacaine 0.75%: 41% +/- 22%, mepivacaine 2%: 39% +/- 21%) and forced expiratory volume at 1 s (ropivacaine 0.5%: 30% +/- 19%, ropivacaine 0.75%: 38% +/- 26%, mepivacaine 2%: 40% +/- 10%). We conclude that, when performing IBP anesthesia, 0.5% ropivacaine does not decrease the incidence of ipsilateral paresis of the hemidiaphragm compared with 0.75% ropivacaine and 2% mepivacaine. IMPLICATIONS: During the first 30 min after placing interscalene brachial plexus anesthesia, 0.5% ropivacaine does not provide clinically relevant advantages in terms of pulmonary function changes compared with either 0.75% ropivacaine or 2% mepivacaine. However, 0.75% ropivacaine allows a short onset, similar to that of mepivacaine, with long postoperative analgesia.     

Extradural anaesthesia for Caesarean section: a double-blind comparison of 0.5% ropivacaine with 0.5% bupivacaine

Seventy-three parturients for elective Caesarean section wereallocated randomly to receive extradural block with 20 ml ofeither 0.5% ropivacaine or 0.5% bupivacaine. If the block didnot reach T6 within 30 mm, another 5 ml of solution was given.If needed, a further 5 ml was given 45 mm after the main dose.The mean total dose of bupivacaine was 23.1 ml (n = 35) andof ropivacaine 23.7 ml (n = 37). There was no significant differencebetween the groups in the profile of sensory block produced.There was no significant difference in the time of onset, orintensity of motor block between the groups but the durationof motor block was significantly shorter in the ropivacainegroup. There was no significant difference in neonatal outcome,as assessed by Apgar score, umbilical cord bloodgas tensionsat delivery or the neurological and adaptive capacity score2 and 24 h after delivery. (Br. J. Anaesth. 1995; 74: 512–516)     

A prospective randomized double-blinded controlled study of ropivacaine 0.75% versus bupivacaine 0.5%-mepivacaine 2% for peribulbar anesthesia

BACKGROUND AND OBJECTIVES: Ropivacaine 1% has recently been used in clinical trials for peribulbar anesthesia. This study aims to compare the safety and the efficacy of ropivacaine 0.75% with that of a 1:1 mixture of bupivacaine 0.5% and mepivacaine 2% for peribulbar anesthesia. METHODS: Two thousand patients undergoing peribulbar anesthesia for elective cataract phacoemulsification were prospectively studied over a 1-year period and randomly assigned to 1 of 2 groups according to the local anesthetic used. One thousand patients were administered peribulbar anesthesia with 9 mL of ropivacaine 0.75% plus 1 mL of hyaluronidase (group R), and 1,000 patients received peribulbar anesthesia with 4 mL of bupivacaine 0.5% plus 4 mL of mepivacaine 2% plus 1 mL of hyaluronidase plus 1 mL of sodium bicarbonate (group BM). Peribulbar anesthesia was always accomplished by the same physician by 2 injections of 5 mL each, with a 25-gauge 25-mm needle. Evaluation was performed by another physician blinded to the technique used and included assessment of pain on local anesthetic injection, ocular and eyelid akinesia, need for top-up injections, onset time and duration of anesthesia, intraoperative analgesia, duration of surgery, hemodynamic parameters, and incidence of perioperative complications. RESULTS: A greater incidence of pain on injection was found in group BM (P<.001). No difference between the groups was found regarding the onset time and the duration of anesthesia. Perioperative analgesia was satisfactory in both groups with no significant difference. Patients in group R showed a reduced need for top-up injection and a better ocular akinesia at 8 and 10 minutes (P<.01). The akinesia of the eyelid was comparable in the 2 groups and complete in all cases at 8 minutes. Cardiac arrhythmias were more frequent in group BM (P<.01). Local complications did not differ between the groups. An increase in mean artierial blood pressure and heart rate was observed in both groups 1 minute after injection of local anesthetic. CONCLUSIONS: Peribulbar anesthesia with ropivacaine provided better ocular akinesia 8 to 10 minutes after block insertion than a bupivacaine-mepivacaine mixture, which reduced the need for top-up injections. Ropivacaine also caused less pain on injection.     

A double-blind comparison of intrathecal S(+) ketamine and fentanyl combined with bupivacaine 0.5% for Caesarean delivery

BACKGROUND: In this prospective, randomized, double-blind, controlled study, we investigated the sensory, motor and analgesic block characteristics of S(+) ketamine, fentanyl and saline given intrathecally (IT) in addition to 0.5% plain bupivacaine (10 mg) for spinal analgesia. METHODS: Ninety ASA I or II adult patients undergoing Caesarean section were randomly allocated to receive 1.0 mL of 0.9% saline in Group S (n = 30), 0.05 mg kg-1 of S(+) ketamine (1.0 mL) in Group K (n =30) or 25 microg (1.0 mL) of fentanyl in Group F (n =30) following 10 mg of plain bupivacaine 0.5% IT. We recorded onset and duration of sensory and motor block, time to reach the maximal dermatomal level of sensory block and duration of spinal analgesia. RESULTS: The onset time of sensory and motor block was significantly shorter in Groups K and F than in Group S (P < 0.014). Their duration was significantly longer in Group F than in Groups K and S (P < 0.009). The time to reach the maximal dermatomal level of sensory block was significantly shorter in Groups K and F than in Group S (P < 0.001). The duration of spinal analgesia was significantly longer in Group F than in Groups K and S (P < 0.001). CONCLUSION: In patients undergoing Caesarean section with spinal analgesia, the addition of S(+) ketamine (0.05 mg kg-1) IT to 10 mg of spinal plain bupivacaine (0.5%) led to rapid onset of both sensory and motor blockade and enhanced the segmental spread of spinal block without prolonging the duration of spinal analgesia, whereas fentanyl provided prolonged analgesia.     

Comparison of 1% lignocaine with 0.5% bupivacaine in digital ring blocks

In a randomised double-blind trial comparing 1% lignocaine with 0.5% bupivacaine in digital ring block, the mean time of onset of complete anaesthesia was 5.8 minutes (range 5 to 10 minutes) for lignocaine and 11.2 minutes (range 8 to 20 minutes) for bupivacaine. The duration of action was 59.6 minutes (S.D. +/- 28.7 minutes) for lignocaine and 476 minutes (S.D. +/- 277 minutes) for bupivacaine. We describe how these differences can be exploited in clinical practice.     

Impact study of the introduction of low-dose epidural (bupivacaine 0.1%/fentanyl 2 microg . mL(-1)) compared with bupivacaine 0.25% for labour analgesia

We conducted a retrospective analysis of the obstetric effects of introducing a low-dose epidural regimen for epidural analgesia in labour. Before this, all women in our unit requesting epidural analgesia for labour received intermittent boluses (10 mL) of 0.25% bupivacaine. After the introduction of the low-dose service in March 2000, intermittent boluses (10 mL) of 0.1% bupivacaine with fentanyl 2 microg . mL(-1) were given. The records of 300 women were examined, 150 who had received the standard regimen before the introduction of the new service and 150 women afterwards. The groups were compared for outcome of labour, quality of analgesia and any adverse events related to the epidural analgesia. There was a significant reduction in the low-dose group in the number of women requiring instrumental delivery (41% vs. 29%, P = 0.04). The need for indwelling bladder catheters was also reduced in the patients receiving the low-dose regimen (21.3% vs. 4.7%, P < 0.001). Duration of analgesia was longer in patients receiving bupivacaine 0.25% (mean minimum time between boluses 42.25 +/- 33.8 vs. 24.37 +/- 19.8 min, P < 0.001). The need for further anaesthetic intervention was higher with the low-dose regimen (24% vs. 34%, P = 0.037). Maternal satisfaction was high in both groups (95 and 97%, respectively). We conclude that the introduction of a low-dose regimen of epidural analgesia for labour reduces the incidence of instrumental deliveries. It also decreases the incidence of bladder catheterisation during labour, but the need for anaesthetic intervention may be greater.     

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).