Postoperative analgesia for outpatient arthroscopic knee surgery with intraarticular clonidine and/or morphine

Both clonidine, an alpha(2) agonist, and morphine, an opioid agonist, provide enhanced patient analgesia after arthroscopic knee surgery when administered via the intraarticular (IA) route. Clonidine potentiates morphine analgesia in the animal model. We designed this study to determine whether clonidine or morphine results in better analgesia and whether their combination would provide superior analgesia to either drug alone. We evaluated 60 patients undergoing arthroscopic knee meniscus repair under local anesthesia with sedation. After surgery, patients were randomized into four IA groups: Group B received 30 mL 0.25% bupivacaine; Group BC received 30 mL 0.25% bupivacaine and clonidine 1 microg/kg; Group BM received 30 mL 0.25% bupivacaine and morphine 3 mg; and Group BCM received 30 mL 0.25% bupivacaine, clonidine 1 microg/kg, and morphine 3 mg. This study revealed a significant benefit from the individual IA administration of both clonidine and morphine. The combination of these drugs resulted in decreased postoperative pain and analgesic use, as well as an increased analgesic duration compared with either drug alone. We conclude that IA clonidine and morphine improved comfort compared with either drug alone in patients undergoing knee arthroscopy.     

Clonidine administered as adjuvant for bupivacaine in ilioinguinal-iliohypogastric nerve block does not prolong postoperative analgesia

BACKGROUND: Coadministration of clonidine with local anesthetics is associated with improvement of the quality of peripheral nerve block and significant prolongation of postoperative analgesia. Better analgesia has been reported with clonidine in ilioinguinal nerve block compared with caudal use. The object of this study was to determine whether adding of 1 microg.kg(-1) clonidine to bupivacaine 0.25% in ilioinguinal-iliohypogastric nerve block prolongs postoperative analgesia in children. METHODS: Ninety-eight children ASA I-II aged between 1 and 12 years, scheduled for elective outpatient herniorrhaphy or orchidopexy were randomly allocated to receive an ilioinguinal-iliohypogastric nerve block either with 0.3 ml.kg(-1) bupivacaine 0.25% plus 1 microg.kg(-1) clonidine or only bupivacaine. Postoperative analgesic needs, time to the first analgesic supplementation and sedation score were assessed in hospital for 6 h postoperatively and at home by telephone call. RESULTS: Demographic data were similar in both groups. There was no statistical difference in the rate of rescue analgesia between the two groups during the first six postoperative hours (20.4% group clonidine vs 30.6% group no clonidine) (P = 0.17). A slight decrease in systolic blood pressure during surgery was reported in the clonidine group. There was no difference in the scores of sedation between the two groups. At home, 10 patients in the clonidine group and nine patients in the nonclonidine group received analgesic medication. There was no difference between the two groups regarding the number of patients receiving analgesic rescue during the first 24 h (log rank = 0.39). Parental satisfaction was high in both groups. CONCLUSIONS: Our study failed to demonstrate any advantage in addition of 1 microg.kg(-1) clonidine to 0.25% bupivacaine for ilioinguinal-iliohypogastric nerve block compared with bupivacaine 0.25% alone.     

Pediatric caudal block with mepivacaine, bupivacaine or a mixture of both drugs: requirement for postoperative analgesia and plasma concentration of local anesthetics

STUDY OBJECTIVES: To assess the effects of pediatric caudal block using mepivacaine, bupivacaine, or a mixture of both drugs on postoperative analgesia, and to examine plasma concentrations of the local anesthetics after caudal injection. DESIGN: Prospective, randomized, double-blind study. SETTING: Operating room and pediatric surgical ward. PATIENTS: 60 ASA physical status I children weighing 10 to 20 kg (26 females, 34 males), and scheduled for inguinal herniorrhaphy. INTERVENTIONS: Patients randomly received caudal block with 1 mL/kg of mepivacaine 1% (Group M, n = 20), 1 mL/kg of bupivacaine 0.25% (Group B, n = 20), or a mixture of 0.5 mL/kg of mepivacaine 1% and 0.5 mL/kg of bupivacaine 0.25% (Group MB, n = 20) after induction of anesthesia with sevoflurane in 50% oxygen (O2). Anesthesia was maintained with 66% nitrous oxide in O2 supplemented with sevoflurane at an end-tidal concentration of less than 1%. MEASUREMENTS AND MAIN RESULTS: Postoperative pain scores using a pediatric pain scale and plasma concentration of each local anesthetic were measured. In Group M, four patients required postoperative analgesics within the first 24 hours. However, no patients required postoperative analgesics in Groups B and MB. In Group M, the plasma concentration of mepivacaine of two patients exceeded 5 microg/kg of the level of toxicity. However, these patients did not show any toxic symptoms. Because a mixture of two local anesthetics halves the concentration of each local anesthetic, the plasma concentrations of mepivacaine and bupivacaine in Group MB were significantly lower than those of Groups M and B. CONCLUSIONS: Pediatric caudal block with a mixture of mepivacaine and bupivacaine is effective for intraoperative and postoperative analgesia.     

Caudal neostigmine,bupivacaine, and their combination for postoperative pain management after hypospadias surgery in children

In a randomized, double-blinded study, we examined the analgesic efficacy of caudal neostigmine, bupivacaine, or a mixture of both drugs in 60 children. After the induction of general anesthesia, children were allocated randomly into three groups (n = 20) to receive a caudal injection of either 0.25% bupivacaine 1 mL/kg, with or without neostigmine 2 micro g/kg, or neostigmine 2 micro g/kg in normal saline 1 mL/kg. Intraoperatively, children receiving caudal bupivacaine or a bupivacaine/neostigmine mixture maintained hemodynamic stability, required less inhaled anesthetics, and had a shorter recovery time compared with the caudal neostigmine alone. Postoperatively, the caudal bupivacaine/neostigmine mixture resulted in superior analgesia compared with the other two groups. Recovery to first rescue analgesic times were (mean +/- SD) 22.8 +/- 2.9 h, 8.1 +/- 5.9 h, and 5.2 +/- 2.1 h in the bupivacaine/neostigmine, bupivacaine, and neostigmine groups, respectively (P < 0.001). In addition, the bupivacaine and neostigmine groups received more doses of paracetamol than the bupivacaine/neostigmine group to maintain adequate analgesia in the first 24 postoperative h. Postoperative vomiting occurred in 25%, 10%, and 30% in the caudal bupivacaine/neostigmine, bupivacaine, and neostigmine groups, respectively (P < 0.01). We conclude that caudal neostigmine 2 micro g/kg provides postoperative analgesia comparable to caudal bupivacaine in children undergoing hypospadias repair surgery. IMPLICATIONS: Caudal neostigmine 2 micro g/kg provides postoperative analgesia comparable to caudal bupivacaine in children undergoing hypospadias repair surgery. Co-administration of the two drugs is associated with extended postoperative analgesia and reduced need for supplementary analgesics.     

Extended "three-in-one" block after total knee arthroplasty: continuous versus patient-controlled techniques

This prospective, randomized, double-blinded study assessed the efficacy of patient-controlled analgesia (PCA) techniques for extended "3-in-1" block after total knee arthroplasty. A total of 45 patients were divided into three groups of 15. Over 48 h, all patients received 0.125% bupivacaine with 1 microg/mL clonidine via a femoral nerve sheath catheter in the following manner: as a continuous infusion at 10 mL/h in Group 1; as a continuous infusion at 5 mL/h plus PCA boluses (2.5 mL/30 min) in Group 2; or as PCA boluses only (10 mL/60 min) in Group 3. Pain scores, sensory block, supplemental analgesia, bupivacaine consumption, side effects, and satisfaction scores were recorded. Pain scores and supplemental analgesia were comparable in the three groups. Bupivacaine consumption was significantly less in Groups 2 and 3 than in Group 1 (P < 0.01), and in Group 3 than in Group 2 (P < 0.01). Side effects and satisfaction were comparable in the three groups. We conclude that extended "3-in-1" block provides efficient pain relief after total knee arthroplasty and that, compared with a continuous infusion, PCA techniques reduce the local anesthetic consumption without compromise in patient satisfaction or visual analog scale scores. Of the two PCA techniques tested, PCA boluses (10-mL lockout; time, 60 min) of 0.125% bupivacaine with 1 microg/mL clonidine was associated with the smallest local anesthetic consumption, and is, therefore, the recommended extended "3-in-1" block technique. IMPLICATIONS: We demonstrated that, after total knee arthroplasty, an extended "3-in-1" block consisting of patient-controlled analgesia boluses (10 mL/60 min) of 0.125% bupivacaine with 1 microg/mL clonidine provides efficient postoperative analgesia and significantly minimizes local anesthetic consumption.     

A comparison of epidural infusions in the combined spinal/epidural technique for labor analgesia

We compared the clinical effects of three epidural infusions initiated after subarachnoid medication was administered as part of the combined spinal/epidural technique for labor analgesia. Fifteen minutes after administering subarachnoid fentanyl 25 microg and 1 mL of bupivacaine 0.25%, and 5 min after an epidural test dose of 3 mL of bupivacaine 0.25%, women were randomized to receive an epidural infusion of saline, bupivacaine 0.125%, bupivacaine 0.0625%, or bupivacaine 0.04% with epinephrine 1:600,000. All epidural infusions were started at 10 mL/h, and all except the Saline Group also received fentanyl 2 microg/mL. The end point of the study was delivery or request for additional medication for analgesia. We found that time until request for additional analgesia was longest in women who received bupivacaine 0.125% (median duration, 300 min) versus saline (median duration, 118 min) (P = 0.0001) and was intermediate for bupivacaine 0.0625% and bupivacaine 0.04% (median duration, 162 and 180 min, respectively) (P = 0.0001 versus saline). Women who received bupivacaine 0.125% had the most motor block. We conclude that all the bupivacaine-based infusions we tested maintained the analgesia from subarachnoid medication longer than saline, with the longest duration, but the most motor block, from bupivacaine 0.125%. IMPLICATIONS: In this prospective, randomized, and double-blinded study we found that initiating an epidural infusion of bupivacaine 0.125% with fentanyl 2 microg/mL at 10 mL/h 15 min after subarachnoid fentanyl 25 microg with 1 mL of bupivacaine 0.25%, followed by an epidural test dose of 3 mL of bupivacaine 0.25%, maintained the analgesia for longer but with more motor block than with either bupivacaine 0.04% or bupivacaine 0.0625%.     

The influence of sufentanil and/or clonidine on the duration of analgesia after a caudal block for hypospadias repair surgery in children

The aim of this study was to evaluate whether the addition of clonidine, or sufentanil, or both, to a bupivacaine solution for a caudal block prolonged the period of analgesia after operation in children. Sixty ASA class I or II boys, aged between 8 months and 13 years, admitted for hypospadias repair were enrolled into a prospective randomised study. After induction of general anaesthesia and endotracheal intubation the children were allocated into four groups. Group I received 0.5 mL kg(-1) bupivacaine 0.25% caudally, in addition group II received 1 microg kg(-1) clonidine, group III 0.5 microg kg(-1) sufentanil and group IV 0.5 microg kg(-1) clonidine and 0.25 microg kg(-1) sufentanil. The concentrations of clonidine and sufentanil in group IV were halved to reduce possible side-effects with higher dosages. Analgesia and side-effects were assessed 2, 4, 6, 8 and 12 h after operation. No significant differences were found among the four groups for the pain scores at 2, 4, 6, 8 and 12 h. All groups had a similar frequency of vomiting and a comparable appetite and quality of night rest during the first 24 h following the operation. There was no significant difference in the requirement for additional doses of analgesics. The addition of sufentanil, or clonidine, or both, to bupivacaine for caudal administration provides no additional clinical benefit over bupivacaine alone.     

Brachial plexus block with midazolam and bupivacaine improves analgesia

PURPOSE: Adjuncts to local anesthetics for brachial plexus block may enhance the quality and duration of analgesia. Midazolam, a water-soluble benzodiazepine, is known to produce antinociception and enhance the effect of local anesthetics when given epidurally or intrathecally. The purpose of this study was to assess the effect of midazolam added to brachial plexus anesthesia. METHODS: A prospective, randomized, double blind study was conducted on 40 ASA I or II adult patients undergoing upper limb surgeries under supraclavicular brachial plexus block. Patients were randomly divided into two groups. Patients in Group B (n = 20) were administered 30 mL of 0.5% bupivacaine and Group BM (n = 20) were given 30 mL of 0.5% bupivacaine with midazolam 50 microg x kg(-1). Hemodynamic variables (i.e., heart rate, noninvasive blood pressure), pain scores and rescue analgesic requirements were recorded for 24 hr postoperatively. RESULTS: The onset of sensory and motor block was significantly faster in Group BM compared to Group B (P < 0.05). Pain scores were significantly higher in Group B compared to Group BM from two hours to 24 hr postoperatively (P < 0.05). Rescue analgesic requirements were significantly less in Group BM compared to Group B (P < 0.05). Hemodynamics and sedation scores did not differ between groups in the post-operative period. CONCLUSION: Midazolam (50 microg x kg(-1)) in combination with 30 mL of bupivacaine (0.5%) hastened onset of sensory and motor block, and improved postoperative analgesia when used in brachial plexus block, without producing any adverse events.     

Clonidine administered as an axillary block does not affect postoperative pain when given as the sole analgesic.

Used as the sole analgesic, clonidine produces analgesia after epidural, intrathecal, and intraarticular administration. We conducted this double-blinded study to determine whether clonidine has analgesic effects when administered into the brachial plexus sheath. At the conclusion of hand or forearm surgery, performed under axillary brachial plexus block, 45 patients were randomly divided into three groups of 15 each to receive, through an axillary catheter, 15 mL of saline (Group Saline), clonidine 150 microg in 15 mL of saline (Group Clonidine), or bupivacaine 15 mL (Group Bupivacaine). The analgesic effects of the three solutions were evaluated for 6 h. Times to onset of pain and to first analgesic request were longer, and the total dose of pain medication was smaller in Group Bupivacaine compared with the other groups. Visual analog scores were significantly lower in Group Bupivacaine. There was no significant difference in time to onset of pain, time to first analgesic request, total dose of pain medication, and visual analog scores between Group Saline and Group Clonidine at any time. We conclude that the administration of clonidine 150 microg into the brachial plexus sheath does not prolong the onset of postoperative pain. IMPLICATIONS: Used as the sole analgesic, clonidine produces analgesia after epidural, intrathecal, and intraarticular administration. It also prolongs the analgesic effect of brachial plexus block when mixed with local anesthetics. In this study, the administration of clonidine 150 microg alone into the brachial plexus sheath did not produce postoperative analgesia.     

Pharmacokinetics of levobupivacaine, fentanyl, and clonidine after administration in thoracic paravertebral analgesia

BACKGROUND AND OBJECTIVES: There is little knowledge of the pharmacokinetics of local anesthetics and adjunctive analgesics after paravertebral blockade. We evaluated the pharmacokinetics of low-dose levobupivacaine, fentanyl, and clonidine after paravertebral analgesia for breast surgery. METHODS: Thirty-eight patients receiving paravertebral analgesia for breast surgery received a 19-mL paravertebral bolus of levobupivacaine 0.25% combined with a 1-mL volume of saline (group L, 13 patients), fentanyl 50 microg (group LF, 13 patients), or clonidine 150 microg (group LC, 12 patients) followed 1 hour later by infusion of levobupivacaine 0.1% (L), levobupivacaine 0.05% with fentany l 4 microg/mL (LF), or levobupivacaine 0.05% with clonidine 3 microg/mL (LC), respectively. Plasma concentrations of study drugs were determined at intervals up to 24 hours after bolus injection. RESULTS: There was rapid absorption of levobupivacaine after bolus with mean (standard deviation) maximum plasma concentration (Cpmax) of 0.51(0.24) microg/mL in a median time to maximum concentration tCpmax of 15 minutes. Mean Cpmax fentanyl and clonidine after bolus were 0.62 (0.37) and 0.79 (0.23) ng/mL, in a median tCpmax of 15 and 22.5 minutes, respectively. Mean Cpmax levobupivacaine after infusion was 0.47 (0.41) microg/mL in a median tCpmax of 24 hours. There was progressive accumulation of fentanyl and clonidine at 24 hours with a mean Cpmax of 0.72 (0.33) and 1.74 (0.70) ng/mL, respectively. CONCLUSIONS: After paravertebral bolus and infusion administration, Cpmax levobupivacaine was within the safe range. Cpmax fentanyl and clonidine were less than the effective levels after IV administration, suggesting that their analgesic effect may be partly attributed to a peripheral mechanism of action.     

The combination of epidural clonidine and S(+)-ketamine did not enhance analgesic efficacy beyond that for each individual drug in adult orthopedic surgery

STUDY OBJECTIVES: To evaluate the benefit of epidural clonidine and S(+)-ketamine combination through the epidural route in adult orthopedic surgery. DESIGN: Randomized double-blinded study. SETTING: Teaching hospital. PATIENTS: Scheduled to undergo knee surgery, 56 American Society of Anesthesiologists physical status 1 and 2 adult patients. INTERVENTIONS: Patients were randomized to 1 of 4 groups to receive the combined epidural-intrathecal technique. A 10-mL epidural injection of either study drug or normal saline was first administered to all patients. Intrathecal anesthesia was performed with 15 mg of bupivacaine. The control group (CG) received epidural saline. The 0.1-mg/kg S(+)-ketamine epidural group received 0.1 mg/kg epidural S(+)-ketamine. The 0.5-microg/kg clonidine epidural group received 0.5 microg/kg epidural clonidine. The S(+)-ketamine/clonidine group received 0.1 mg/kg epidural S(+)-ketamine plus 0.5 microg/kg epidural clonidine. MEASUREMENTS AND MAIN RESULTS: Pain and adverse effects were evaluated by visual analog scale. Rescue analgesics were available to patients. The groups were demographically similar. Sensory level to pinprick, surgical and anesthetic time, and visual analog scale scores for pain at first rescue medication were similar among the groups. The time to first rescue analgesic (minute) was lowest in CG (P < .005). The CG required more rescue analgesics in 24 hours than any of the other groups (P < .0005). Patients who received either epidural clonidine, S(+)-ketamine, or both displayed similar analgesia. The frequency of adverse effects was similar among groups (P > .05). CONCLUSIONS: The association of epidural clonidine or S(+)-ketamine did not result in a greater analgesic effect in the model of acute postoperative pain studied, although the interaction of epidural clonidine and S(+)-ketamine is not attributable to sharing of a common second messenger system.     

Intraperitoneal application of bupivacaine plus morphine for pain relief after laparoscopic cholecystectomy

BACKGROUND AND OBJECTIVE: Intraperitoneal administration of a local anaesthetic in combination with an opioid, for the relief of postoperative pain, has already been reported except after laparoscopic cholecystectomy. This study was aimed at assessing the analgesic effect of the intraperitoneal administration of bupivacaine and morphine in patients undergoing laparoscopic cholecystectomy. METHODS: At the end of laparoscopic cholecystectomy, in a double-blind, randomized manner, one of the following injections was given intraperitoneally. There were 30 patients in each group: Group 1, physiological saline 30 mL; Group 2, bupivacaine 0.25% 30 mL; Group 3, bupivacaine 0.25% 30 mL plus morphine 2 mg. In addition, Group 2 received 2 mg intravenous (i.v.) morphine in 2 mL saline, and Groups 1 and 3, 2 mL saline intravenously. Patients' postoperative pain was evaluated using a visual analogue scale and a verbal rating score. The postoperative analgesic requirement was assessed by the total dose of metamizol administered by an i.v. patient-controlled analgesia (PCA) device. Pain, vital signs, supplemental analgesic consumption and side-effects were recorded for all patients for 24 h. RESULTS: There were no differences between the three groups regarding pain scores (at rest and coughing) during the study except in the first 2 h, when scores were lower for patients receiving intraperitoneal bupivacaine plus i.v. morphine (P < 0.05). Supplemental consumption of metamizol was significantly lower (P < 0.05) in Group 3 than in Group 1 during the first 6 h after surgery. However, the cumulative doses of metamizol were also lower in Group 2 than in Groups 1 and 3 over the entire study (2025 +/- 1044 mg vs. 4925 +/- 1238 and 4125 +/- 1276mg; P < 0.05). CONCLUSIONS: In patients undergoing laparoscopic cholecystectomy, the intraperitoneal administration of morphine plus bupivacaine 0.25% reduced the analgesic requirements during the first 6 postoperative hours compared with the control group. However, the combination of intraperitoneal bupivacaine 0.25% and i.v. morphine was more effective for treatment of pain after laparoscopic cholecystectomy.     

Low-dose intrathecal clonidine combined with sufentanil as analgesic drugs in abdominal gynecological surgery

STUDY OBJECTIVES: To determine whether a low dose of spinal clonidine either alone or combined with sufentanil would provide effective analgesia following abdominal surgery, as a supplement to bupivacaine spinal anesthesia. DESIGN: Randomized double-blind study. SETTING: Gynecological surgery, teaching hospital. PATIENTS: 73 ASA physical status I and II patients undergoing gynecological abdominal surgery with spinal anesthesia. INTERVENTIONS: Patients were randomly assigned to one of four groups and prospectively studied to examine anesthesia, analgesia, and adverse effects. The control group received saline as the test drug; the sufentanil group received 10 microg of sufentanil; the clonidine group received 30 microg of clonidine; and the sufentanil/clonidine group received 5 microg of sufentanil plus 15 microg of clonidine. All groups received intrathecal 15 mg of bupivacaine (3 mL) plus the intrathecal test drug (2 mL). The concept of visual analog scale (VAS) was introduced. All patients were premedicated with intravenous midazolam. Rescue analgesics were available. MEASUREMENTS AND MAIN RESULTS: The groups were demographically the same. Sensory block to pinprick at 10 min was higher for clonidine and sufentanil/clonidine groups compared to the control group (p < 0.02). Anesthetic time (Bromage score 2) was also longer for clonidine and sufentanil/clonidine groups compared to the control and sufentanil groups (p < 0.05). Time to first rescue analgesics was shorter in the control group compared to the other groups (p < 0.02). The number of IM diclofenac dose injections in 24 hours was higher in the control group compared to all other groups (p < 0.05). The incidence of adverse effects and ephedrine consumption were similar among groups. CONCLUSIONS: Intrathecal 15- and 30-microg clonidine doses expanded the anesthesia sensory block and duration of motor block, and provided analgesia.     

The effects of preoperative inflammation on the analgesic efficacy of intraarticular piroxicam for outpatient knee arthroscopy

We conducted a double-blinded study in 90 patients undergoing elective arthroscopic knee surgery to determine whether there is a role of inflammation in the analgesic efficacy of intraarticular piroxicam. Standardized general anesthetic techniques were used for all patients. At the end of the operation, after harvesting synovial biopsies, patients were randomized into three intraarticular groups equally. Group 1 received 25 mL saline, Group 2 received 25 mL 0.25% bupivacaine, and Group 3 received 25 mL 0.25% bupivacaine and piroxicam 20 mg. After microscopic examination of the synovial materials, the patients were divided into two subgroups, inflammation positive (I+) and inflammation negative (I-). Preoperatively and postoperatively at 1, 2, 4, and 6 h, pain levels, analgesic duration, and postoperative analgesic consumption were recorded. Analgesic duration was significantly longer in the I+ subgroup than the I- subgroup of Group 3 (P < 0.05). Pain scores at 1, 2, and 4 h postoperatively were significantly lower in the I+ subgroup than the I- subgroup of Group 3 (P < 0.05), whereas there were no significant differences among the subgroups of Group 1 and 2. We concluded that preoperative inflammation is one of the most important determinants of analgesic efficacy of intraarticular piroxicam. IMPLICATIONS: Intraarticular administration of piroxicam along with bupivacaine improves postoperative analgesia in synovial inflammation before surgery.     

Extended femoral nerve sheath block after total hip arthroplasty: continuous versus patient-controlled techniques

We assessed the efficacy of patient-controlled analgesia (PCA) techniques for extended femoral nerve sheath block after total hip arthroplasty. Forty-five patients were divided into three groups of 15. Over 48 h, all patients received 0.125% bupivacaine with clonidine 1 microg/mL and sufentanil 0.1 microg/mL via a femoral nerve sheath catheter as a continuous infusion at 10 mL/h in Group 1, as PCA boluses only of 10 mL/h in Group 2, or as PCA boluses of 5 mL per 30 min in Group 3. Pain scores, sensory block, supplemental analgesia, bupivacaine consumption, side effects, and satisfaction scores were recorded. Pain scores at rest and supplemental analgesia were comparable in the three groups. At 48 h, pain relief on movement was significantly better in Group 3 than in Group 1 (P = 0.01). Bupivacaine consumption was significantly less in Groups 2 and 3 than in Group 1 (P < 0.001). Side effects were comparable in the three groups. Satisfaction scores were significantly higher in Group 3 than in the other groups (P < 0.01). We conclude that, to maintain extended femoral nerve sheath block after total hip arthroplasty, PCA techniques reduce the local anesthetic consumption without compromise in patient satisfaction or visual analog scale scores. Of the two PCA techniques tested, PCA boluses (5 mL per 30 min) of 0.125% bupivacaine with clonidine 1 microg/mL and sufentanil 0.1 microg/mL are associated with the smallest local anesthetic consumption and the most patient satisfaction.     

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

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

Clonidine combined with a long acting local anesthetic does not prolong postoperative analgesia after brachial plexus block but does induce hemodynamic changes

Clonidine in brachial plexus block prolongs analgesia of local anesthetics of short and intermediate duration. We performed a prospective randomized double-blinded study to determine the efficacy and adverse effects of clonidine mixed with a long-acting local anesthetic on postoperative analgesia. Sixty adult patients underwent elective rotator cuff repair using interscalene brachial plexus block combined with general anesthesia and were randomly divided into one of the following three groups. Placebo (n = 20): interscalene block with 40 mL of 0.5% bupivacaine with epinephrine (1/200000) and 1 mL of 0.9% saline, completed by 1 mL of 0.9% saline IM in the controlateral shoulder; Control (n = 20): interscalene block with 40 mL of 0.5% bupivacaine with epinephrine and 1 mL of 0. 9% saline, completed by 150 microg (=1 mL) of clonidine IM; Clonidine (n = 20): interscalene block with 40 mL of 0.5% bupivacaine with epinephrine and 150 microg (=1 mL) of clonidine, completed by 1 mL of 0.9% saline IM. During anesthesia hemodynamic variables and fractional expired isoflurane concentration (FeISO) were recorded. The following postoperative variables were assessed: duration of interscalene block, quality of pain relief on a visual analog scale, side effects, and consumption of morphine with a patient-controlled analgesia device over 48 h. Patient characteristics were comparable. During anesthesia mean arterial pressure, heart rate, and FeISO were significantly decreased in Clonidine and Control groups compared with Placebo group. Duration of analgesia, defined as the time elapsed from interscalene injection to the first morphine request, was 983 +/- 489 min in the Placebo, 909 +/- 160 min in the Control, and 829 +/- 159 min in the Clonidine groups. Pain scores and consumption of morphine at 24 h and 48 h showed no differences among the three groups. We conclude that adding 150 microg of clonidine in interscalene block does not prolong analgesia induced by 40 mL of bupivacaine 0.5% with epinephrine, but decreases mean arterial blood pressure and heart rate. Implications: Clonidine in brachial plexus block does not improve postoperative analgesia when mixed with a long-lasting anesthetic. Nevertheless, with or without clonidine, bupivacaine in interscalene block provides a long-lasting analgesia of approximately 15 h.     

Opioid-free analgesia following total knee arthroplasty--a multimodal approach using continuous lumbar plexus (psoas compartment) block, acetaminophen, and ketorolac.

BACKGROUND AND OBJECTIVES: Traditionally, postoperative analgesia following total knee arthroplasty (TKA) has been provided by neuraxial or peripheral regional techniques with supplemental administration of opioids. We report an alternative method of postoperative pain management for patients undergoing TKA in whom the use of systemic or neuraxial opioids may result in significant side effects. CASE REPORT: A 74-year-old woman with a history of protracted nausea and vomiting after systemic and neuraxial opioid administration presented for left total knee arthroplasty. A spinal anesthetic with postoperative continuous lumbar plexus (psoas) analgesia was planned. A quadriceps motor response was elicited and a 20-gauge catheter was advanced through an 18-gauge insulated Tuohy needle into the psoas sheath. After 30 mL of bupivacaine 0.5% with 100 microg clonidine was administered through the psoas catheter, a spinal anesthetic (2 mL 0.5% bupivacaine at the L2-3 interspace) was performed. A continuous psoas infusion of 0.2% bupivacaine with 2 microg/mL clonidine at 8 mL/h was initiated in the recovery room. The psoas infusion was subsequently changed to 0.2% bupivacaine without clonidine and the rate increased to 10 mL/h. Supplemental analgesia with oral acetaminophen 1 g every 4 to 6 hours alternating with intravenous ketorolac 15 mg every 6 hours provided satisfactory analgesia, with visual analog scale (VAS) scores of 0 to 2 at rest and 3 to 4 with movement. The psoas catheter was removed 48 hours postoperatively because of prolongation of the prothrombin time. VAS scores remained 0 to 3 throughout the remainder of her hospitalization. CONCLUSION: A multimodal approach consisting of continuous lumbar plexus (psoas) block and nonopioid analgesics successfully provided postoperative pain relief in our patient and facilitated her physical rehabilitation after total knee arthroplasty.     

Clonidine as coadjuvant in eye surgery: comparison of peribulbar versus oral administration

STUDY OBJECTIVE: To determine whether the administration of peribulbar or oral clonidine would enhance analgesia and anesthesia in ophthalmologic surgery. DESIGN: Randomized double-blind study. SETTING: Teaching hospital. PATIENTS: 60 ASA physical status I and II adult patients scheduled for unilateral ophthalmologic surgery with peribulbar block. INTERVENTIONS: Patients were assigned to one of 4 groups, and premedicated with oral 2 mL volume (clonidine or placebo). The peribulbar eye block consisted of local anesthetics plus 1 mL of the test drug. The control group (CG) received oral saline as premedication and peribulbar saline as the test drugs. The clonidine eye group (Clo-eye G) received oral saline and peribulbar 30 microg clonidine. The clonidine oral group (Clo-oral G) received oral 150 microg clonidine and peribulbar saline. The clonidine eye+oral group (Clo eye+oral G) had oral 75 microg clonidine and peribulbar 15 microg clonidine. MEASUREMENTS AND MAIN RESULTS: Perioperative assessment included anesthesia, analgesia, blood cortisol; and adverse effects. The groups were demographically similar. The latency time to the onset of the peribulbar block was shorter in the Clo-eye G compared to the CG (p < 0.05). The CG presented higher blood pressure levels throughout surgery, compared to the others (p < 0.05). The time to first rescue analgesics was longer in all patients who received peribulbar clonidine compared to the CG (p < 0.05). Analgesic consumption was lesser in the Clo-eye G compared to the CG (p < 0.05). The blood cortisol level was higher during the intraoperative period in all groups (preoperative vs. intraoperative values) (p < 0.01). CONCLUSION: Despite the higher intraoperative blood cortisol levels, 30 microg peribulbar clonidine decreased the onset time to anesthesia, while 15 and 30 microg peribulbar clonidine prolonged the time to first rescue analgesics in patients under peribulbar block, without increasing the frequency of adverse effects. Conversely, oral administration of clonidine alone did not enhance anesthesia or analgesia following eye block, suggesting a local mechanism of action of clonidine.     

Fentanyl and clonidine as adjunctive analgesics with levobupivacaine in paravertebral analgesia for breast surgery

The addition of fentanyl or clonidine to levobupivacaine was evaluated in patients undergoing breast surgery under general anaesthesia with intra- and postoperative paravertebral analgesia. Patients were randomly allocated to four groups: Group L received 19 ml bolus levobupivacaine 0.25% plus 1 ml saline followed by an infusion of levobupivacaine 0.1%; Group LF received 19 ml bolus levobupivacaine 0.25% plus fentanyl 50 microg followed by an infusion of levobupivacaine 0.05% with fentanyl 4 microg x ml(-1); Group LC received 19 ml bolus levobupivacaine 0.25% plus clonidine 150 microg followed by an infusion of levobupivacaine 0.05% with clonidine 3 microg x ml(-1); Group C (control) received general anaesthesia without paravertebral analgesia. All groups received postoperative i.v. morphine patient controlled analgesia (PCA). Although mean (SD) postoperative PCA morphine consumption was decreased in LF [7.9 (4.1) mg] and LC [5.9 (3.5) mg]vs L [27.7 (8.6) mg] or C patients [21.7 (5.5) mg], p < 0.01, paravertebral fentanyl and clonidine were associated with significantly increased vomiting and hypotension, respectively.