Björn Holmström

A systematic review of the peripheral analgesic effects of intraarticular morphine.

The analgesic effects of intraarticular morphine are controversial. To systematically evaluate the effects, we performed a review of the literature and a metaanalysis of the peripheral effects of morphine injected intraarticularly. Research databases were searched to identify articles in which peripheral analgesic effects of morphine were studied in patients undergoing arthroscopic knee procedures under local, regional, or general anesthesia. The review was performed on three issues: does morphine injected intraarticularly produce analgesia, is it a dose-dependent effect, and, if so, is the effect systemic or mediated via peripheral opioid receptors? Visual analog score (VAS) and analgesic consumption were studied during the early phase (0–2 h), intermediate phase (2–6 h), and late phase (6–24 h) postoperatively after injection of morphine intraarticularly. Metaanalysis of these effect variables was performed by the weighted-analysis technique, and the essential homogeneity assumption was tested by the &khgr;2 test. Forty-five articles could be identified in which the effects of morphine were studied in a prospective, randomized manner, and 32 of these studies included a placebo control. Pooled analyses of data from 19 studies suitable for metaanalysis showed an improvement in analgesia after morphine compared with placebo in the order of 12–17 mm on the VAS during all three phases of treatment. Studies with high quality scores showed somewhat smaller improvements. Total analgesic consumption could not be analyzed statistically, but the number of studies showing decreased analgesic consumption or no differences between groups was identical (six and six). No clear dose-response effect was seen when VAS was used as a measure of pain, but it was seen when area under the curve was used as a measure of pain. A systemic effect of peripherally-injected morphine was not possible to exclude because of the very limited data available. We conclude from this metaanalysis that intraarticularly administered morphine has a definite but mild analgesic effect. It may be dose dependent, and a systemic effect cannot be completely excluded.

Risk of catheter migration during combined spinal epidural block : percutaneous epiduroscopy study

Combined spinal epidural (CSE) block with the needle-through-needle technique has become increasingly popular during recent years. However, the risk of epidural catheter penetrating dura mater through the hole made by the spinal needle (migration) is a major concern. In 15 fresh cadavers a percutaneous epiduroscopy technique with a rigid epiduroscope and video recording was used to assess the risk of catheter migration when a CSE block is performed. The experimental sequence included (a) one dural hole made by the spinal needle, (b) multiple (five) dural holes made by the spinal needle, and (c) a dural hole made by Tuohy needle. Twenty-four experimental sequences were performed in the lumbar region. Four sequences were failures due to technical problems. In the remaining 20 cases, the anatomic structures in the epidural space were recognized easily. The epidural space appears to be only a potential space, kept open either by epiduroscope or by repeated injections of air or saline. The dural holes made by Tuohy and spinal needles, and the ease of difficulty of catheter penetration through these holes, were clearly visible. Extensive tenting of the dura was seen in all subjects. It was impossible to force an 18-gauge epidural catheter through the dural hole after a single dural puncture made by a 25-gauge spinal needle. After multiple (five) dural punctures with the spinal needle, the epidural catheter penetrated the perforated dura in 1 of 20 cases. The epidural catheter penetrated the dural hole made by the Tuohy needle in 9 of 20 cases. The distribution of fat, rather than any dorso median connective tissue band, influences the course of epidural catheter in epidural space. We conclude that the risk of epidural catheter migration through the dural hole during uncomplicated combined spinal-epidural block is very small. (Anesth Analg 1995;80:747-53)

Combined spinal-epidural technique

Background For the past 16 years the combined spinal-epidural (CSE) technique has been extensively researched and developed to the point where it is now in widespread use. Along with the use of low-dose mixtures of local anesthetics and opioids, and the introduction of fine-gauge pencil-point needles, CSE is being increasingly recognized as another important addition to the armamentarium of the anesthesiologist. Method. One hundred and forty-two publications focusing on the CSE technique, or on questions concerning CSE-related issues, were reviewed. Out of 33 double-blind or controlled studies, 23 directly investigated the CSE technique. Fifty-four prospective studies and letters made directly relevant points on advantages or problems with CSE. Twenty-one book chapters, reviews and editorials were included, 11 of them concerning the use of CSE technique. Results. All CSE techniques which may be used for surgical anesthesia, for analgesia in labor or for postoperative pain management are described. Indications, advatages, disadvantages, and the various methods for performing CSE procedures, including sequential CSE block, are described and reviewed, along with the equipment currently available for their administration. Conclusion. The CSE technique offer many potential advantages over continuous epidural or subarachnoid methods alone, including a reduction in drug dosage, the ability to eliminate motor blockade and to achieve highly selective sensory blockade and optimize analgesia. These features hold great promise for minimizing the hazards and side effects of traditional epidural and subarachnoid techniques. Controversial fears, risks, and pitfalls of the CSE technique and of continuous epidural and subarachnoid methods are debated and discussed.

The combined spinal-epidural technique.

In recent years, the use of regional anaesthesia techniques for surgery, obstetrics and post operative pain management have increased in popularity. The combined spinal-epidural (CSE) technique has attained widespread popularity for patients undergoing major surgery below the umbilicus who may require prolonged and effective postoperative analgesia. The CSE technique is now well established in several institutions. This chapter includes the clinical experience, advantages and potential problems, and discusses future perspectives of the CSE technique.

Postoperative pain relief following intrathecal bupivacaine combined with intrathecal or oral clonidine

Background: The purpose of the present study was to evaluate the postoperative analgesic and adverse effects of equal doses of oral or intrathecal clonidine in spinal anaesthesia with bupivacaine plain.

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 &mgr;g (Group BC15), or clonidine 30 &mgr;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 &mgr;g to bupivacaine prolonged time to first analgesic request and decreased postoperative pain with minimal risk of hypotension. We conclude that clonidine 15 &mgr;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.

Combined spinal epidural block versus spinal and epidural block for orthopaedic surgery

In a controlled study a single segment combined spinal epidural (CSE) block was compared with spinal or epidural block for major orthopaedic surgery. Seventy-five patients, age 52–86 yr, were randomly assigned to receive one of the three blocks. Bupivacaine 0.5% was used for surgical analgesia. The postoperative pain relief after 4.0 mg epidural morphine was compared with the analgesic effect of 0.2 or 0.4 mg morphine administered intrathecally. With the spinal technique good or excellent surgical analgesia and muscle relaxation were achieved rapidly (11.8 ± 1.1 min). The time taken to provide an equally effective and reliable block with the CSE technique was no longer (14.9 ± 2.2 min). For epidural block with the catheter technique more time was required (35.9 ± 3.9 min) to provide acceptable surgical conditions (P < 0.05). Perioperative sedatives and concomitant analgesics were required more frequently and in larger doses by the patients undergoing surgery with epidural block (P < 0.05) than with CSE or spinal block. Our study demonstrated that the analgesia after surgery provided by 0.2 and 0.4 mg morphine administered intrathecally was comparable to that provided by 4.0 mg of epidural morphine. It is concluded that the analgesia and surgical conditions provided by the spinal and CSE blocks were similar and were superior to those provided by an epidural block.RésuméLors d’une étude contrôlée, on compare le bloc que produit l’association rachi-épidurale (CSE) à celui que produit chacune des deux techniques utilisées séparément en chirurgie orthopédique lourde. Soixante-quinze patients âgés de 52 à 86 ans sont assignés au hasard à recevoir un des trois blocs. La bupivacaïne 0,5% est employée pour l’analgésie chirurgicale. Le soulagement postopératoire avec morphine épidurale 4,0 mg est comparé avec celui que procure la morphine 0,2 ou 0,4 intrathécale. Avec la technique rachidienne, une analgésie de bonne à excellente et la relaxation musculaire surviennent rapidement (11,8 ±1,1 min). Le temps requis pour obtenir les mêmes résultats avec la technique CSE n’est pas plus long (14,9 ± 2,2 min). Pour le bloc épidural avec cathéter, plus de temps est requis (35,9 ± 3,9 min) pour l’atteinte de conditions chirurgicales acceptables (P < 0,05) qu’avec le CSE ou la rachi. Notre étude montre que l’analgésie postopératoire obtenue par la morphine 0,2 et 0,4 mg intrathécale est comparable à celle produite par la morphine 0,4 épidurale. On conclut que les condition produites par la rachi et la CSE sont indentiques entre elles et supérieures à celles du bloc épidural.

Improved analgesia with clonidine when added to local anesthetic during combined spinal-epidural anesthesia for hip arthroplasty: a double-blind, randomized and placebo-controlled study

Background:  The perioperative effects of intrathecal and epidural clonidine combined with local anesthetic were evaluated in 60 patients undergoing hip arthroplasty.

Intrathecal and oral clonidine as prophylaxis for postoperative alcohol withdrawal syndrome: a randomized double-blinded study.

In this study, we evaluated the effect of intrathecal and oral clonidine as supplements to spinal anesthesia with lidocaine in patients at risk of postoperative alcohol withdrawal syndrome (AWS). We hypothesized that clonidine would have a prophylactic effect on postoperative AWS. Forty-five alcohol-dependent patients (daily ethanol intake >60 g) scheduled for transurethral resection of the prostate were double-blindly randomized into three groups. All patients received hyperbaric lidocaine 100 mg intrathecally. The diazepam group (DiazG) was premedicated with diazepam 10 mg orally; the intrathecal clonidine group (Cloni/tG) received a placebo (saline) tablet and clonidine 150 &mgr;g intrathecally; and the oral clonidine group (Clonp/oG) received clonidine 150 &mgr;g orally. For patients diagnosed with AWS, the Clinical Institute Withdrawal Assessment for Alcohol, revised scale, was used. Twelve patients in the DiazG had symptoms of AWS, compared with two in the Cloni/tG and one in the Clonp/oG. The median Clinical Institute Withdrawal Assessment for Alcohol, revised scale, score was 12 in the DiazG versus 1 in the clonidine-treated groups. Two patients in the DiazG had severe delirium. Patients receiving oral clonidine had a slightly decreased mean arterial blood pressure 6–12 h after spinal anesthesia (P < 0.05); patients in the DiazG had a hyperdynamic circulatory reaction 24–72 h after surgery. In conclusion, preoperative clonidine 150 &mgr;g, intrathecally or orally, prevented significant postoperative AWS in ethanol-dependent patients.

The combined spinal–epidural technique

Epidural and spinal blocks are well-accepted regional techniques, but they have several disadvantages. The CSE technique can reduce or eliminate the risks of these disadvantages. CSE block combines the rapidity, density, and reliability of the subarachnoid block with the flexibility of continuous epidural block to extend duration of analgesia. The CSE technique is used routinely at many institutions, particularly for major orthopedic surgery and in obstetrics. It has been used in tens of thousands of patients without any reports of major problems. Although at first sight the CSE technique appears to be more complicated than epidural or spinal block alone, intrathecal drug administration and siting of the epidural catheter are both enhanced by the combined, single-space, needle-through-needle method. Concerns about the epidural catheter entering the theca via the small puncture hole are now considered to be unfounded, but as with all epidural catheter techniques, vigilant monitoring of the patient during and after any injection is paramount. CSE is an effective way to reduce the total drug dosage required for anesthesia or analgesia. The intrathecal injection achieves rapid onset with minimal doses of local anesthetics and opioids, and the block can be prolonged with low-dose epidural maintenance administration. In addition, the sequential CSE method can be used to extend the dermatomal block with minimal additional drugs or even saline. Reduction in total drug dosage has made truly selective blockade possible. Many studies have confirmed that low-dose CSE with local anesthetic and opioid, or low-dose epidural block alone, will provide effective analgesia with minimal motor and proprioceptive block. Such neurologic selective blockade has made it possible for most patients to walk and bear down normally in labor or postoperatively. There remains concern about the risk of infection being increased when the CSE technique is used in place of epidural block alone. Despite a recent flurry of reports of meningitis with CSE procedures, there is no evidence the CSE block is more hazardous than epidural or subarachnoid block alone. Arguably, the single-space, needle-through-needle CSE technique will continue to improve with new needle designs and other advances to improve further the success rate and reduce complications, such as neurotrauma, PDPH, and infection. Over the past decade it has become clear that the CSE technique is a significant advance in regional blockade.