A comparison of spinal anesthesia characteristics following intrathecal bupivacaine or levobupivacaine in lumbar disc surgery

Purpose

While bupivacaine is the most frequently used local anesthetic for spinal anesthesia, use of levobupivacaine in clinical practice has advanced recently. The aim of our study was to compare the clinical and anesthetic effects of isobaric bupivacaine and isobaric levobupivacaine when administered intrathecally in patients undergoing lumbar disc surgery.

Methods

ASA I–III, 60 patients were enrolled in this study. Only patients with unilateral single-level (L4–5) lumbar disc hernia were selected and operated in each group and all were operated by the same surgeon. Patients were randomized into two groups, as group B (n = 30): 15 mg 0.5 % isobaric bupivacaine, or group L (n = 30): 15 mg 0.5 % isobaric levobupivacaine received intrathecally. The level of sensory block dermatome, degree of motor block, intraoperative sensory and motor block characteristics, and postoperative recovery times of spinal anesthesia were evaluated. The satisfaction scores of the surgeon and patients, intraoperative hemodynamic changes, intraoperative and postoperative complications were recorded.

Results

The maximum level of sensory blockade was significantly higher in the levobupivacaine group (group L 7 ± 1.63, group B 8.6 ± 1.76 thoracic dermatome, p < 0.05). There was no significant difference in the onset time of sensory (group L 6 ± 3 min, group B 9 ± 4 min) and motor (in group L 7 ± 3 min, in group B 10 ± 4 min) blockade (p > 0.05). There was no significant difference between the groups regarding duration of operation (group L 49 ± 7.3 min, group B 52 ± 8.1, p > 0.05). Recovery times of sensory (175 ± 57 min) and motor (216 ± 59 min) blockade were significantly shorter in the levobupivacaine group (p < 0.05). Mobilization was also earlier in the levobupivacaine group (339 ± 90 min, p < 0.05). Patients’ satisfaction and intraoperative, postoperative complications were similar between the two groups.

Conclusions

Our results showed that block recovery time was shorter in the levobupivacaine group, this may be a disadvantage for longer operative procedures. But with proper patient selection this can be eliminated. Recovery time was shorter in levobupivacaine group. Therefore, postoperative neurological examination can be done earlier. In addition, early mobilization can be an advantage for postoperative recovery.     

Epidural fentanyl improves the onset and spread of epidural mepivacaine analgesia

Purpose

To determine the extent of enhanced blockade by the combined use of epidural fentanyl and mepivacaine. We compared the onset of hypoalgesia, analgesia and the threshold of pressure pain.

Methods

Thirty patients were randomly divided into three groups. The fentanyl group received 10 ml saline containing 0.1 mg fentanyl, mepivacaine group received 10 ml mepivacaine 1% and a mixed group received 10 ml mepivacaine 1% with 0.1 mg fentanyl. All solutions, without epinephrine, were injected through an epidural catheter at T_5–6 to T_6–7. The change in sensation, loss of pin-prick and pain threshold sensation, measured by pressure algometer, were assessed at 2.5-min intervals for 15 min at the T₄ dermatome. Spread of analgesia was determined at 15 min.

Results

Loss of pinprick was more rapid in the mixed, 11.0 ± 2.7 (SD) min, than in the mepivacaine group, 15.0 ± 2.9 min, (P < 0.05), although there was no difference in change of sensation. Pressure pain threshold increased with time in the mepivacaine (P < 0.05) and mixed (P < 0.05) groups. It was higher in the mixed than in the fentanyl and mepivacaine groups at 5, 7.5 and 10 min (P < 0.05). The lower level of analgesia was lower in the mixed than in the mepivacaine groups (P < 0.05). Blood pressure was unchanged in the three groups, but heart rate decreased at 7.5, 10, 12.5, and 15 min in the mepivacaine and mixed groups (P < 0.05).

Conclusions

The addition of fentanyl to mepivacaine accelerates the onset of analgesia and enhances the analgesic effect of epidural block.     

Lower-Dose Mepivacaine Plus Fentanyl May Improve Spinal Anesthesia for Knee Arthroscopy

Background

Previous work indicates that 30 mg isobaric mepivacaine 1.5% plus 10 μg fentanyl produces reliable anesthesia for knee arthroscopy with a more rapid recovery profile than 45 mg mepivacaine.

Questions/Purposes

This randomized controlled trial compared plain mepivacaine to three reduced doses of mepivacaine with 10 μg fentanyl for spinal anesthesia.

Methods

Following written informed consent, subjects undergoing outpatient knee arthroscopy were prospectively randomized into one of four groups: mepivacaine 37.5 mg (M37.5); mepivacaine 30 mg plus fentanyl 10 μg (M30/F10); mepivacaine 27 mg plus fentanyl 10 μg (M27/F10); and mepivacaine 24 mg plus fentanyl 10 μg (M24/F10). The spinal was evaluated by the blinded anesthetist and surgeon. In the post-anesthesia care unit, sensory and motor block resolution was assessed. Subjects rated their satisfaction with the overall experience.

Results

Group M30/F10 (n = 6) had two “fair” anesthetics, and group M27/F10 (n = 10) had one “fair” and one “inadequate” anesthetic. Both groups were eliminated from further enrollment per study protocol. The recovery profiles showed little difference between groups M37.5 and M30/F10, except for motor block resolution (median (25th percentile, 75th percentile): 171 (135, 195) and 128 (120, 135), respectively). Groups M27/F10 and M24/F10 demonstrated recovery profiles that were faster than group M37.5. Patient satisfaction was 10/10 for all groups.

Conclusions

Adding fentanyl 10 μg to a lower dose of mepivacaine 1.5% can lead to quicker recovery profiles. However, this advantage of a quicker recovery must be weighed against the likelihood of an incomplete anesthetic.

Electronic supplementary material

The online version of this article (doi:10.1007/s11420-015-9454-8) contains supplementary material, which is available to authorized users.     

Knee strength retention and analgesia with continuous perineural fentanyl infusion after total knee replacement: randomized controlled trial

Purpose

Despite providing adequate pain relief, a femoral nerve block can induce postoperative muscle weakness after total knee arthoplasty (TKA). Fentanyl has been shown to have peripheral effects but has not been used as a perineural infusate alone after TKA.

Methods

Sixty patients scheduled for TKA were randomized to one of three blinded groups: a continuous 24 h infusion of either fentanyl 3 μg/ml, ropivacaine 0.1 %, or 0.9 % normal saline through a femoral nerve sheath catheter at 10 ml/h. The main outcome was maximum voluntary isometric contraction (MVIC) in the quadriceps femoris (knee extension), measured by a handheld dynamometer (Nm/kg). Other variables assessed were preoperative and postoperative visual analog scale (VAS) scores, hamstrings MVIC (knee flexion), active range of motion of the operative knee, distance ambulated, incidence of knee buckling, supplemental morphine usage, postoperative side effects, and serum fentanyl levels.

Results

Quadriceps MVIC values were significantly greater in the fentanyl group compared to the group that received ropivacaine (median values, 0.08 vs. 0.03 Nm/kg; p = 0.028). The incidence of postoperative knee buckling upon ambulation was higher in the ropivacaine group compared to the fentanyl group, although not statistically significant (40 % vs. 15 %, respectively; p = 0.077). VAS scores while ambulating were not significantly different between the fentanyl group and the ropivacaine group (p = 0.270). Postoperative morphine consumption, nausea and vomiting, and resting VAS scores were similar among the three groups.

Conclusions

A continuous perineural infusion of fentanyl produced greater strength retention than ropivacaine post-TKA.     

Quality of lidocaine analgesia with and without midazolam for intravenous regional anesthesia

Purpose

Midazolam has analgesic effects mediated by gamma aminobutyric acid-A receptors. This study was designed to evaluate the effect of midazolam on anesthesia and analgesia quality when added to lidocaine for intravenous regional anesthesia (IVRA).

Methods

Forty patients undergoing hand surgery were randomly assigned to two groups to receive IVRA. The control group received 3 mg/kg lidocaine 2% w/v diluted with saline to a total volume of 40 ml, and the midazolam group received an additional 50 μg/kg midazolam. Sensory and motor block onset and recovery times, tourniquet pain, intraoperative analgesic requirements, sedation, and anesthesia quality were recorded. Postoperative pain and sedation scores, time to first analgesic requirements, analgesic use in the first 24 h, and side effects were noted.

Results

Sensory and motor block onset and recovery times did not differ significantly between groups. Tourniquet pain scores were lower at 10, 15, 20, and 30 min (P < 0.0001) in the midazolam group. Three (15%) patients in the midazolam group required fentanyl for tourniquet pain compared with thirteen (65%) patients in the control group (P = 0.02). Patients in both groups received fentanyl once. Midazolam group showed that significantly less patients required diclofenac for postoperative analgesia (P < 0.01) and analgesic-free period during first postoperative 24 h was significantly longer (726.8 ± 662.8 min vs. 91.0 ± 35.9 min, P < 0.0001). Postoperative pain scores were lower (P < 0.0001) and sedation scores higher (P < 0.05) for the first 2 h in the midazolam group.

Conclusion

Addition of midazolam to lidocaine for IVRA improves anesthesia quality and enhances intraoperative and postoperative analgesia without causing side effects.     

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.     

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

Background

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

Methods

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

Results

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

Conclusion

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

The role of electrical stimulation in ultrasound-guided subgluteal sciatic nerve block: a retrospective study on how response pattern and minimal evoked current affect the resultant blockade

Purpose

Nerve stimulation may be combined with ultrasound imaging for a block of deeply located nerves such as the sciatic nerve in the subgluteal region. At present, it is unknown how the use of nerve stimulation affects blockade after this nerve block. We retrospectively compared the effects of the two types of motor response and those of minimal evoked current above and below 0.5 mA on ultrasound-guided subgluteal sciatic nerve block using mepivacaine or ropivacaine, two local anesthetics with different onset time and duration.

Methods

We reviewed records and video images of patients who, from April 2008 until October 2011, received ultrasound-guided subgluteal sciatic nerve block combined with nerve stimulation using 20 ml of either 1.5 % mepivacaine with 1:400,000 epinephrine or 0.5 % ropivacaine. Sensory and motor blockade data for 30 min after the block and for the duration of the blockade were gathered. Patients for whom any data were missing, the video image was poor, and/or intraneural injection was observed during the block were excluded from the study. The same data were compared in two ways: regarding the motor response pattern between the response of the tibial nerve and the common peroneal nerve, and regarding the minimal current between low current (< 0.5 mA) and high current (≥0.5 mA). The primary endpoints were the onset and duration of blockade of the sciatic nerve block.

Results

We analyzed the data of 170 and 99 patients who received mepivacaine and ropivacaine, respectively. The progress of sensory and motor blockade as well as block duration was similar between different motor response patterns after both anesthetics. The proportion of patients who developed sensory block of the tibial nerve and motor block at 30 min was higher in the low minimal current group than in the other group receiving mepivacaine. Patients in the former group also had longer block duration. With ropivacaine, complete motor blockade was present at 30 min in a higher proportion of patients after lower minimal evoked current than after higher minimal evoked current.

Conclusion

When ultrasound-guided subgluteal sciatic nerve block was conducted with nerve stimulation, the motor response pattern did not markedly affect the progress of sensory or motor blockade or block duration. Lower minimal evoked current was associated with faster onset in sensory and motor block and longer block duration after mepivacaine and faster onset in motor block after ropivacaine. The clinical significance of this, however, has yet to be determined.     

Mepivacaine Spinal Anesthesia Facilitates Rapid Recovery in Total Knee Arthroplasty Compared to Bupivacaine

Background

Mepivacaine as a spinal anesthetic for rapid recovery in total knee arthroplasty (TKA) has not been assessed. The purpose of this study is to compare spinal mepivacaine vs bupivacaine for postoperative measures in patients undergoing primary TKA.

Sevoflurane/propofol coadministration provides better recovery than sevoflurane in combined general/epidural anesthesia: a randomized clinical trial

Purpose

A classic general anesthesia is performed by induction with an intravenous hypnotic (such as propofol) and maintenance with a volatile anesthetic (such as sevoflurane). The aim of the present study was to compare the effects of a propofol/sevoflurane maintenance regimen with that of a sevoflurane regimen on recovery profiles.

Methods

One hundred and sixty patients, who were ASA 1 or 2, 45–65 years of age, and scheduled for elective gastrointestinal surgery under combined general/epidural anesthesia, were allocated randomly to receive the sevoflurane maintenance regimen (group S, n = 80) or sevoflurane/propofol regimen (group SP, n = 80). After induction, anesthesia was maintained with sevoflurane in group S and sevoflurane with propofol (1.2 μg/ml target plasma concentration) in group SP. Bispectral index (BIS) values were maintained within 40–60 during the maintenance. Time to extubation, incidence of serious coughing and agitation, and other recovery characteristics were evaluated during emergence.

Results

The time to awakening and extubation in group SP were 7.2 ± 2 min and 8.0 ± 1.8 min, respectively, which were shorter than those results in group S (12.3 ± 1.5 and 12.8 ± 1.6 min, respectively) (P < 0.05). The incidence of serious coughing and agitation in SP (30 % and 25 %) was lower than that of group S (68 % and 53 %) (P < 0.05). BIS value, pain score, requirements of analgesics and antiemetics in the PACU, and length of stay in the PACU were similar in the two groups.

Conclusions

Compared to sevoflurane maintenance, coadministration of propofol and sevoflurane provides faster awakening and extubation with a low incidence of emergence coughing and agitation.     

Comparative effects of flurbiprofen and fentanyl on natural killer cell cytotoxicity, lymphocyte subsets and cytokine concentrations in post-surgical intensive care unit patients: prospective, randomized study

Purpose

The purpose of this study was to compare the effect of the long-term administration of flurbiprofen and fentanyl in the intensive care unit on natural killer cell cytotoxicity (NKCC), lymphocyte subsets and cytokine levels.

Methods

In this prospective study, patients scheduled for at least 48 h sedation after neck surgery were randomly assigned to two groups called group N and group F. Group N patients were sedated with propofol and flurbiprofen after surgery (n = 12), while group F patients were sedated with propofol and fentanyl (n = 13). The NKCC, lymphocyte subsets, and plasma levels of tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, and IL-10 were measured before and at the end of surgery, on postoperative day (POD) 1 and POD2.

Results

The NKCC was significantly higher on POD1 in group N than in group F (14.5 ± 11.2 versus 6.3 ± 4.1 %, p < 0.05), the difference between the groups disappearing on POD2. Lymphocyte subsets and plasma levels of cytokines were not significantly different between the two groups during the study period.

Conclusions

Transient suppressive effects on NKCC were observed in the fentanyl group as compared to the flurbiprofen group. This suggests that when choosing postoperative analgesics, physicians should bear in mind the potential immunosuppressive effects of these agents in patients requiring prolonged sedation in the intensive care unit.     

The interaction of antiemetic dose of droperidol with propofol on QT interval during anesthetic induction

Purpose

We investigated the effect of low-dose droperidol on heart rate-corrected QT (QTc) interval and interaction with propofol.

Methods

Seventy-two patients undergoing upper limb surgery were included in this study. Patients were randomly allocated to one of three groups: group S (n = 24), which received 1 ml saline; group D1 (n = 24), which received 1.25 mg droperidol; or group D2 (n = 24), which received 2.5 mg droperidol. One minute later, fentanyl (3 μg/kg) was administered. Two minutes after fentanyl administration, anesthesia was induced using propofol (1.5 mg/kg) and vecronium. Tracheal intubation was performed 3 min after the administration of propofol. Heart rate, mean arterial pressure, bispectral index, and QTc interval were recorded at the following time points: immediately before the droperidol injection (baseline); 3 min after the saline or droperidol injection; 3 min after the propofol injection; and 2 min after tracheal intubation.

Results

Compared to baseline, the QTc interval in group S and group D1 was significantly shorter after propofol injection, but recovered after tracheal intubation. In group D2, the QTc interval was significantly prolonged after droperidol injection, but recovered after propofol injection, and was significantly prolonged after tracheal intubation.

Conclusions

We found that saline or 1.25 mg droperidol did not prolong QTc interval, whereas 2.5 mg droperidol prolonged the QTc interval significantly, and that propofol injection counteracted the prolongation of the QTc interval induced by 2.5 mg droperidol.     

Remifentanil temporarily improves renal function in adult patients with chronic kidney disease undergoing orthopedic surgery

Purpose

The objective of this study was to confirm the renal protective effect of remifentanil-based anesthesia in perioperative adult patients with chronic kidney disease (CKD).

Methods

A total of 90 non-dialysis perioperative adult patients with CKD, with preoperative estimated glomerular filtration rate from creatinine (eGFRcreat) values of lower than 50 ml/min/1.73 m², who had undergone orthopedic surgery under general anesthesia were retrospectively selected. The subjects were divided into two groups according to whether or not remifentanil was used for anesthesia management: group R, in which remifentanil was used for anesthesia management (n = 45), and group NR, in which remifentanil was not used for anesthesia (n = 45). eGFRcreat was measured pre-surgery (pre), 7 days after surgery (day-7), and 14 days after surgery (day-14).

Results

In group R, both day-7 eGFRcreat (52.2 ± 17.0 ml/min/1.73 m²) and day-14 eGFRcreat (49.7 ± 15.5 ml/min/1.73 m²) were significantly higher than the pre eGFRcreat (40.7 ± 7.5 ml/min/1.73 m²) (day-7: p < 0.01; day-14: p < 0.01). In group NR, on the other hand, pre eGFRcreat (37.8 ± 7.6 ml/min/1.73 m²), day-7 eGFRcreat (41.2 ± 10.9 ml/min/1.73 m²), and day-14 eGFRcreat (40.2 ± 10.5 ml/min/1.73 m²) values were similar. Furthermore, both day-7 eGFRcreat and day-14 eGFRcreat were significantly higher in group R than in group NR (day-7: p < 0.01; day-14: p < 0.01).

Conclusions

Our findings suggest that anesthesia management using remifentanil may have a renal protective effect in perioperative adult CKD patients undergoing orthopedic surgery.     

The parasacral sciatic nerve block does not induce anesthesia of the obturator nerve

Purpose

The ability of the parasacral sciatic nerve block (PSNB) to induce anesthesia of the obturator nerve remains controversial. Our objective was to evaluate the anesthesia of the obturator nerve after a PSNB.

Methods

Forty patients scheduled to undergo knee surgery (anterior cruciate ligament reconstruction) were included in this prospective, randomized, controlled study. Patients were randomized to receive PSNB alone (control group, n = 20) or PSNB in combination with an obturator nerve block (obturator group, n = 20). After evaluation for 30 min, the two groups received a femoral nerve block, and patients were taken to surgery. The obturator nerve blockade was assessed by measurement of adductor strength at baseline (T0) and every 10 min during the 30-min evaluation (T10, T20, and T30). Pain scores after tourniquet inflation and during surgery were compared between the two groups. The requirement for additional intravenous analgesia and/or sedation was also recorded.

Results

The two groups had comparable demographic and surgical characteristics. Four patients were excluded from the study because of PSNB or femoral nerve block failure. The adductor strength values were similar between groups at T0 but were significantly lower in the obturator group at T10, T20, and T30 (p < 0.0001). Patients in the obturator group reported less pain than those in the control group (p < 0.05). They also required less additional intravenous sedation and/or analgesia (p < 0.05).

Conclusion

This clinical study demonstrated that the PSNB is an unreliable means of inducing anesthesia of the obturator nerve and emphasizes the need to block this nerve separately to induce adequate analgesia during knee surgery.     

Intravenous dexmedetomidine, but not midazolam, prolongs bupivacaine spinal anesthesia

Purpose

Midazolam has only sedative properties. However, dexmedetomidine has both analgesic and sedative properties that may prolong the duration of sensory and motor block obtained with spinal anesthesia. This study was designed to compare intravenous dexmedetomidine with midazolam and placebo on spinal block duration, analgesia, and sedation in patients undergoing transurethral resection of the prostate.

Methods

In this double-blind randomized placebo-controlled trial, 75 American Society of Anesthesiologists’ I and II patients received dexmedetomidine 0.5 μg · kg^?1, midazolam 0.05 mg · kg^?1, or saline intravenously before spinal anesthesia with bupivacaine 0.5% 15 mg (n = 25 per group). The maximum upper level of sensory block and sensory and motor regression times were recorded. Postoperative analgesic requirements and sedation were also recorded.

Results

Sensory block was higher with dexmedetomidine (T 4.6 ± 0.6) than with midazolam (T 6.4 ± 0.9; P < 0.001) or saline (T 6.4 ± 0.8; P < 0.001). Time for sensory regression of two dermatomes was 145 ± 26 min in the dexmedetomidine group, longer (P < 0.001) than in the midazolam (106 ± 39 min) or the saline (97 ± 27 min) groups. Duration of motor block was similar in all groups. Dexmedetomidine also increased the time to first request for postoperative analgesia (P < 0.01 compared with midazolam and saline) and decreased analgesic requirements (P < 0.05). The maximum Ramsay sedation score was greater in the dexmedetomidine and midazolam groups than in the saline group (P < 0.001).

Conclusion

Intravenous dexmedetomidine, but not midazolam, prolonged spinal bupivacaine sensory blockade. It also provided sedation and additional analgesia.     

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.     

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

Purpose

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

Methods

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

Results

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

Conclusions

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

Effects of sevoflurane on carrageenan- and fentanyl-induced pain hypersensitivity in Sprague-Dawley rats

Purpose

Opioids are widely used for anesthesia but paradoxically induce postoperative pain hypersensitivity via N-methyl-d-aspartate (NMDA) receptor modulation. Sevoflurane effects on opioid-induced hyperalgesia have not been yet evaluated in vivo. Nevertheless, some experimental in vitro studies reported anti-NMDA receptor properties for sevoflurane. The aim of this study was to evaluate sevoflurane effects on fentanyl-induced hyperalgesia in opioid-naive rats and in rats with inflammatory pain.

Methods

Sevoflurane effects on hyperalgesia were evaluated in Sprague-Dawley rats: opioid-naive rats, rats treated with fentanyl (4 × 60 μg kg^?1) and rats with inflammatory pain (carrageenan) treated with fentanyl (4 × 60 μg kg^?1). On day zero, subcutaneous fentanyl injections were administered and inflammatory pain was induced with one carrageenan injection in one hind paw. Rats were exposed to low concentrations of sevoflurane (1.0 or 1.5%) on day zero prior to fentanyl injections and inflammatory pain induction, and for the duration of the fentanyl analgesic effect. The nociceptive threshold (Randall-Selitto test) was evaluated daily for 7 days. On day seven, naloxone was injected and the nociceptive threshold was assessed 5 min later.

Results

In rats without inflammatory pain but treated with fentanyl on day zero, sevoflurane 1.0% reversed the early (day zero) and long-lasting (day zero to day three) hyperalgesia classically described after high-doses of fentanyl (P < 0.05). This sevoflurane concentration antagonized the hyperalgesia induced by naloxone on day seven (P = 0.33). In a second experiment in rats with inflammatory pain, exposure to low concentrations of sevoflurane (1.0 and 1.5%) did not reduce fentanyl-induced hyperalgesia (P > 0.05), but nevertheless antagonized the naloxone induced hyperalgesia on day seven (P = 0.061).

Conclusion

Relatively low sevoflurane concentrations (1.0%) reverse fentanyl-induced hyperalgesia in rats without inflammatory pain. Nevertheless, the lack of effect of sevoflurane concentrations of 1.0% and 1.5% to oppose hyperalgesia following high-dose fentanyl and inflammatory pain suggests that sevoflurane anti-hyperalgesic properties are weak.     

Steuerung der axillären Multiinjektionstechnik zur Plexusanästhesie

Background

Ultrasound guidance is still a young method in regional anesthesia when compared to nerve stimulation and only a few studies exist comparing these two techniques in an axillary multiple injection approach.

Aim

This prospective, randomized, observer-blinded study compared an ultrasound-guided (SONO) quadruple injection axillary block (out of plane, perineural) with a nerve stimulation-guided (STIM) triple injection axillary block for upper limb surgery.

Material and methods

A total of 60 patients were randomized to either the SONO (n?=?30) or STIM (n?=?30) group. For the block 40–50 ml mepivacaine 1.5?% (plexus) and 5–10 ml mepivacaine 0.5?% (subcutaneous in the medial skin of the arm) was used. Anesthesia time was recorded as the primary end point. After evaluation of block-related pain using a visual analog scale (VAS) a blinded observer tested sensory and motor function of the median nerve (MED), ulnar nerve (ULN), radial nerve (RAD), musculocutaneous nerve of the upper limb (MUC) and medial cutaneous nerve of the forearm (CAM) at defined times. The main outcome variable was onset time (defined loss of sensory/motor function).

Results

No differences were observed between the groups in terms of onset time (single nerves 10–20 min, plexus 20–25 min) and success rate (SONO 90?%, STIM 89?%). Patient satisfaction as measured by block-related pain score (VAS 2 cm), complications (vascular puncture SONO 7?%, STIM 11?%; paresthesia SONO 21?%, STIM 22?%) and patient acceptance (SONO 92?%, STIM 91?%) showed no differences. Performance time was shorter in the SONO group (6.68?±?1.72 min vs. 8.05?±?2.58, p?=?0.02).

Conclusion

Nerve stimulation-guided axillary plexus blocks performed by trained anesthesiologists may result in similar onset times and success rates compared to ultrasound-guided blocks.     

Postoperative analgesia using fentanyl plus celecoxib versus epidural anesthesia after laparoscopic colon resection

Purpose

Effective postoperative analgesia is essential to a patient’s recovery after laparoscopic colon resection (LCR). We introduce a new analgesic protocol using fentanyl plus celecoxib following LCR.

Methods

The subjects of this retrospective comparative study were 137 patients who underwent LCR, 63 of whom were treated with 72 h of epidural anesthesia (group E), and 74 of whom were treated with 24 h of fentanyl intravenous injection followed by 7 days of oral celecoxib (group FC). We evaluated the safety and efficacy of this new protocol.

Results

The combination of fentanyl and celecoxib maintained a low postoperative pain score (<1.5, evaluated by the FACES Pain Scale) and reduced the need for rescue analgesic drugs for 7 days (groups E vs. FC: 5.39 ± 3.77 vs. 2.79 ± 2.92, p < 0.001). The postoperative hospital stay was almost equal for the two groups (E vs. FC: 11.1 ± 4.5 vs. 10.3 ± 4.8 days, p = 0.315). The operating room stay other than for surgery was significantly shorter for group FC (E vs. FC: 128.7 ± 30.5 vs. 107.2 ± 17.0 min, p < 0.001). Neither group experienced complications, apart from one group FC patient, who suffered transient nausea and vertigo.

Conclusions

The new analgesic protocol using fentanyl plus celecoxib is an effective and time-saving strategy for LCR.