Alain Borgeat

Acute and nonacute complications associated with Interscalene block and shoulder surgery. A prospective study

BackgroundThe incidence, etiology, and evolution of complications after interscalene brachial plexus block (ISB) are not well-known. The authors prospectively monitored 521 patients for complications during the first 9 months after ISB. MethodsA total of 521 adults scheduled for elective shoulder surgery performed with an ISB were included in this prospective study. The ISB procedure was standardized for all patients. Acute complications were recorded. Patients were observed daily (for 10 days) for paresthesias, dysesthesias, pain not related to surgery, and muscular weakness and were evaluated at 1, 3, 6, and 9 months after surgery. Persistence of paresthesias, dysesthesias, pain not related to surgery, or muscular weakness was investigated at 1 or 3 months by means of electroneuromyography. Final evaluation was performed at 9 months. ResultsA total of 520 patients completed the study; one was excluded after surgical axillary nerve damage. Two hundred thirty-four patients had an interscalene catheter. Acute complications consisted of one pneumothorax (0.2%) and one episode of central nervous system toxicity (incoherent speech; 0.2%). At 10 days, 74 patients (14%) were symptomatic, and none had muscular weakness. At 1 month, 41 patients (7.9%) had symptoms, and none had muscular weakness. Thirty patients underwent electroneuromyography; sulcus ulnaris syndrome (n = 8), carpal tunnel syndrome (n = 2), and complex regional pain syndrome (n = 1) were diagnosed. At 3 months 20 patients (3.9%) were symptomatic, and none had muscular weakness. All underwent electroneuromyography; carpal tunnel syndrome (n = 2), complex regional pain syndrome (n = 4), plexus neuropathy (n = 1), and plexus damage (n = 1) were diagnosed. At 6 months, 5 patients (0.9%) were symptomatic. At 9 months, 1 patient (0.2%) had persistence of dysesthesia. ConclusionsInterscalene brachial plexus block performed with a standardized technical approach, material, and drugs is associated with an incidence of short- and severe long-term complications of 0.4%. In case of persistent paresthesia, dysesthesia, or pain not related to surgery after ISB, sulcus ulnaris syndrome, carpal tunnel syndrome, or complex regional pain syndrome should be excluded since specific treatment may be required.

Subhypnotic Doses of Propofol Possess Direct Antiemetic Properties

Propofol is associated with a low incidence of postoperative nausea and vomiting. In a prospective, randomized, double-blind, placebo-controlled study, we investigated the possible direct antiemetic properties of a subhypnotic dose of propofol. Fifty-two ASA physical status I or II patients, aged 15–60 yr with nausea and vomiting after minor gynecologic, orthopedic, or digestive tract surgery, were included in the study and received either propofol (10 mg = 1 mL) or placebo (1 mL Intralipid) intravenously in the postanesthesia care unit. Patients treated with propofol experienced a larger reduction in nausea and vomiting than patients treated with placebo (81% vs 35% success rate; P < 0.05). Patients successfully treated had a similar incidence of relapse (propofol 28%; placebo 22%) within the first 30 min after therapy. Thirty-three percent of the propofol-treated patients and 44% of the placebo-treated patients showed a minor increase in sedation. The level of postoperative pain did not change in either group. Hemodynamic values remained unchanged in both groups. Pain on injection (7.6%) or dizziness (3.6%) only occurred in the propofol group. We conclude that propofol has significant direct antiemetic properties.

Patient-controlled Analgesia after Major Shoulder Surgery Patient-controlled Interscalene Analgesia versus Patient-controlled Analgesia

Background: The authors compared patient‐controlled interscalene analgesia (PCIA) with local anesthetics with intravenous patient‐controlled analgesia (PCA) with opioids to manage postoperative pain after major shoulder surgery. Methods: Forty patients scheduled for elective major shoulder surgery were prospectively randomized to receive either PCIA or PCA. Before surgery, all patients had an interscalene block. In the PCIA group, a catheter was introduced within the interscalene sheath. Six hours after the initial block, patients received for 48 h either a continuous infusion of 0.15% bupivacaine through the interscalene catheter at a rate of 5 ml/h plus a bolus of 3 or 4 ml with a lock‐time of 20 min (group PCIA) or a continuous intravenous infusion of nicomorphine at a rate of 0.5 mg/h plus a bolus of 2 or 3 mg with a lock‐time of 20 min (group PCA). Pain relief was regularly assessed using a visual analog scale, side effects were noted, and the patients were asked to rate their satisfaction at the end of the study. Results: Pain relief was significantly better controlled in the PCIA group at t = 12 and 18 h (P < 0.05). Vomiting and pruritus were 0 versus 25% and 0 versus 25% for the PCIA and PCA groups, respectively (P < 0.05). Patient satisfaction was greater in the PCIA group (P < 0.05). Time of first bolus administration and paracetamol supplement were similar in both groups. Conclusions: The use of the PCIA technique was uncomplicated and provided better pain relief than PCA during the first 18 h after operation. The incidence of side effects such as vomiting and pruritus was significantly decreased with the use of PCIA, and patient satisfaction was superior in the PCIA group.

Evaluation of the Lateral Modified Approach for Continuous Interscalene Block after Shoulder Surgery

Background: Continuous interscalene block is the technique of choice for postoperative pain relief treatment after shoulder surgery. The authors prospectively evaluated the modified lateral approach for the performance of the interscalene catheter block and monitored 700 patients for clinical efficacy and complications during the first 6 months after placement of the catheter. Methods: A total of 700 adults scheduled to undergo elective shoulder surgery performed with an interscalene brachial plexus block through an interscalene catheter were included in this study. The interscalene brachial plexus block procedure was standardized for all patients. Difficulties in placement of the catheter, clinical efficacy of anesthesia and analgesia, patient satisfaction, and acute and chronic complications were recorded. Patients were observed daily for 5 days for any complications and were evaluated at 1, 3, and 6 months after surgery. Persistence of neurologic complication was investigated by electroneuromyography. Results: A total of 700 adults completed the study. Easy placement of the catheter (one attempt) was achieved in 86% of the patients. Resistance to thread the catheter was encountered in 6%; no major complications were observed during injection of the initial bolus. The success rate for anesthesia was 97%. Postoperative analgesia was efficient in 99%. The concentration and the rate of infusion of ropivacaine had to be increased in 31 patients (6%). In five patients (0.7%), signs of local infection around the puncture point were noted; in one patient (0.1%), a collection of pus was surgically drained. Patient satisfaction was 9.6 on a scale of 0‐10. Minor neurologic complications (paresthesias, dysesthesias, pain not related to surgery) were observed in 2.4%, 0.3%, and 0% at 1, 3, and 6 months, respectively. At 1 month, three sulcus ulnaris syndromes, one carpal tunnel syndrome, and one complex regional pain syndrome were diagnosed. Two patients (0.2%) had sensory-motor deficit, which necessitated 19 and 28 weeks to recover. Electromyography was suggestive of partial axonotmesis. Conclusion: The lateral modified approach provides good conditions for placement of the interscalene catheter. Anesthesia and analgesia performed through the catheter are efficient. The rates of infection and neurologic complications are low, and patient satisfaction is high.

Patient-controlled interscalene analgesia with ropivacaine 0.2% versus bupivacaine 0.15% after major open shoulder surgery: the effects on hand motor function.

We compared the effects of patient-controlled interscalene analgesia with ropivacaine 0.2% and patient-controlled interscalene analgesia (PCIA) with bupivacaine 0.15% on hand grip strength after major open shoulder surgery. Sixty patients scheduled for elective major shoulder surgery were prospectively randomized to receive in a double-blinded fashion either ropivacaine or bupivacaine through an interscalene catheter. Before surgery, all patients received an interscalene block (ISB) with either 40 mL of 0.6% ropivacaine or 40 mL of 0.5% bupivacaine. Six h after ISB, the patients received a continuous infusion of either 0.2% ropivacaine or 0.15% bupivacaine for 48 h. In both groups, the PCIA infusion rate was 5 mL/h plus a bolus of 4 mL with a lockout time of 20 min. Strength in the hand was assessed preoperatively, 24 h, and 48 h after ISB and 6 h after stopping the infusion of local anesthetic. The presence of paresthesia in the fingers was checked. Pain relief was assessed using a visual analog scale; side effects were noted, and the patients rated their satisfaction 54 h after the block. A significant decrease of strength in the hand was observed in the Bupivacaine group 24, 48, and 54 h after ISB (P < 0.05). Paresthesia was more frequently reported in the Bupivacaine group for the second and third fingers 48 h after ISB (P < 0.05) and in the first three fingers 6 h after discontinuation of the local anesthetic infusion (P < 0.05). The pain score was similar in the two groups at all times, and patient satisfaction was comparable between the two groups. We conclude that the use of the PCIA technique with ropivacaine 0.2% or bupivacaine 0.15% provides a similar pain relief after major shoulder surgery. However, ropivacaine 0.2% is associated with better preservation of strength in the hand and less paresthesia in the fingers. Implications We compared the patient-controlled interscalene analgesia technique with ropivacaine 0.2% and bupivacaine 0.15% after major open shoulder surgery. For similar pain control ropivacaine is associated with better preservation of strength in the hand and less paresthesia in the fingers.

An evaluation of the infraclavicular block via a modified approach of the Raj technique.

UNLABELLED Infraclavicular plexus block has recently become a technique of increasing interest. However, no approach has provided easily identifiable landmarks, good conditions for catheter placement, and lack of complications (mainly pneumothorax). We describe a modified approach of the Raj technique based on the identification of the anterior acromial process, jugular notch, and emergence of the axillary artery within the axillary fossa, with the arm abducted to 90 degrees and elevated by approximately 30 degrees. We evaluated the clinical characteristics of this approach by injecting 40 to 50 mL of ropivacaine 0.6% in 150 patients scheduled for elective surgery of the forearm, wrist, or hand. Success was defined as a sensory block of the 5 nerves with territories distal to the elbow within 30 min after performing the block. The success rate was 97% when a distal response (flexion or extension of the wrist or fingers) was elicited and 44% when a proximal (contraction of the triceps, biceps) was obtained using a nerve stimulator. Complications were rare: aspiration of blood was seen in 2% of patients and hematoma was seen at the puncture site in 0.6%; no pneumothorax occurred. Eleven patients (7%) complained of some pain during the procedure. We conclude that the modified approach of the Raj technique for infraclavicular block is very effective when a distal nerve stimulator response is obtained with a small complication rate and a high degree of patient satisfaction. IMPLICATIONS We describe a modified approach of the Raj technique for the infraclavicular brachial plexus. The elicitation of a distal nerve stimulator response is associated with a high success rate, a low incidence of complications and a high degree of patient satisfaction.

From Cocaine to Ropivacaine: The History of Local Anesthetic Drugs

In 1850, about three centuries after the conquest of Peru by Pizzaro, the Austrian von Scherzer brought a sufficient quantum of coca leaves to Europe to permit the isolation of cocaine. As suggested by his friend Sigmund Freud, descriptions of the properties of the coca prompted the Austrian Koller to perform in 1884 the first clinical operation under local anesthesia, by administration of cocaine on the eye. The use of cocaine for local and regional anesthesia rapidly spread throughout Europe and America. The toxic effects of cocaine were soon identified resulting in many deaths among both patients and addicted medical staff. Local anesthesia was in a profound crisis until the development of modern organic chemistry which led to the synthesis of pure cocaine in 1891. New amino ester local anesthetics were synthesized between 1891 and 1930, such as tropocaine, eucaine, holocaine, orthoform, benzocaine, and tetracaine. In addition, amino amide local anesthetics were prepared between 1898 and 1972 including nirvaquine, procaine, chloroprocaine, cinchocaine, lidocaine, mepivacaine, prilocaine, efocaine, bupivacaine, etidocaine, and articaine. All of these drugs were ostensibly less toxic than cocaine, but they had differing amounts of central nervous system (CNS) and cardiovascular (CV) toxicity. Bupivacaine is of special interest because of its long duration of action and history of clinical application. Synthesized in 1957, the introduction of bupivacaine on the market in 1965 paralleled the progressive and cumulative reports of CNS and CV toxicity, leading to the restriction of its use and the identification of a special therapy-resistant CV toxicity. Numerous experimental studies were conducted to identify the fine cellular mechanism of this toxicity, which refines our understanding of the action of local anesthetics. The identification of optically active isomers of the mepivacaine family led to the selection of ropivacaine, a pure S-(-) enantiomer, whose toxicology was selectively and extensively studied before its introduction on the market in 1996. During the rapid and extensive use of ropivacaine in the clinic, unwanted side-effects have been found to be very limited.

Postoperative nausea and vomiting in regional anesthesia: a review.

ANESTHESIA has become remarkably safe, and while death and permanent damage have become rare occurrences, other sequelae of anesthesia are gaining more importance. Postoperative nausea and vomiting (PONV) still is the most troublesome adverse event encountered in the recovery room, despite advances in prevention and treatment. The incidence of PONV has remained high and has a major negative impact on patient satisfaction about the overall surgical experience. Furthermore, the ongoing trend toward ambulatory procedures has increased the focus on PONV as its occurrence may delay discharge or cause unanticipated hospital admission. General anesthesia has long been considered as causing a greater frequency and severity of PONV than regional anesthetic techniques. Recent studies investigating this time-honored dictum in a controlled manner mostly, but not unanimously, confirmed it. Accordingly, considerable effort has been invested to examine etiology, define patients at risk, and outline preventive and therapeutic strategies in patients undergoing general anesthesia. Reviews dealing with PONV have discussed almost exclusively general anesthesia and largely ignored regional anesthesia. This contrasts with the increasing popularity of regional anesthesia. A survey in Europe showed that one third of patients are undergoing regional anesthesia for their operative procedure. In France, the proportion of regional anesthesia increased from 15 to 25% of all anesthetics administered from 1980 to 1996. The number of local anesthetic and analgesic agents available for regional anesthesia has increased over the last two decades. Since the introduction of intrathecal and epidural morphine in 1979, a multitude of medications, such as synthetic opioids, 2-agonists, and cholinesterase inhibitors, have been introduced in an attempt to enhance the action of local anesthetics. The decision about their usefulness will not only rely on their effects on nerve blockade and pain relief, but also on their influence on side effects such as PONV. This review focuses on PONV in the setting of perioperative regional anesthesia. General aspects of PONV, such as physiology, patient, and perioperative factors involved are discussed. Few studies regarding these issues have been specifically devoted to regional anesthesia. Therefore, much information must be derived from investigations of general anesthesia. Specific regional anesthetic techniques and the influence of adjunctive medications on PONV are also presented. Combined general–regional anesthesia is purposefully excluded, avoiding the many variables introduced by general anesthesia. A final section is devoted to continuous peripheral nerve blocks and their possible impact on PONV.

Patient-controlled interscalene analgesia with ropivacaine 0.2% versus patient-controlled intravenous analgesia after major shoulder surgery: effects on diaphragmatic and respiratory function.

Background The authors compared the effects of patient-controlled interscalene analgesia (PCIA) with ropivacaine 0.2% and patient-controlled intravenous analgesia (PCIVA) with opioids on hemidiaphragmatic excursion and respiratory function after major shoulder surgery. Methods Thirty-five patients scheduled for elective major shoulder surgery were prospectively randomized to receive either PCIA or PCIVA. All patients received an interscalene block before surgery. In the PCIA group, a catheter was introduced between the anterior and middle scalene muscles. Six hours after the initial block, patients received for 48 h either a continuous infusion of 0.2% ropivacaine through the interscalene catheter at a rate of 5 ml/h plus a bolus dose of 3 or 4 ml with a lockout time of 20 min (PCIA group) or a continuous intravenous infusion of nicomorphine at a rate or 0.5 mg/h plus a bolus dose of 2 or 3 mg with a lockout time of 20 min (PCIVA group). Hemidiaphragmatic excursion and respiratory function were assessed with the patient in a 45° semirecumbent position the day before the operation and 20 min (in the operating room), 24 h, and 48 h after the initial block by means of ultrasonography and spirometry, respectively. Pain relief was regularly assessed, side effects were noted, and patient satisfaction was rated 6 h after the end of the study. Results Hemidiaphragmatic excursion was similar in the two groups 20 min after interscalene block. Hemidiaphragmatic excursion was increased in the PCIA group on the nonoperated side 24 and 48 h after the interscalene block (P < 0.05). Pulmonary function was similar in the two groups at each time. Pain was better controlled in the PCIA group at 12 and 24 h (P < 0.05). The incidence of nausea and vomiting were 5.5%versus 60% for the PCIA and PCIVA groups, respectively (P < 0.05). Patient satisfaction was greater in the PCIA group (P < 0.05). Conclusions The use of PCIA or PCIVA techniques to provide analgesia after major shoulder surgery is associated with similar effects on respiratory function. In the PCIA group, hemidiaphragmatic excursion showed a significantly greater amplitude 24 and 48 h after the initial block on the nonoperated side. The PCIA technique provided better pain control, a lower incidence of side effects, and a higher degree of patient satisfaction.

Infectious risk of continuous peripheral nerve blocks.

CONTINUOUS peripheral nerve block (CPNB) techniques continue to be increasingly used. CPNB catheter infection is an issue that has received little attention to date. The frequency of infection associated with peripheral nerve catheters remains poorly defined. Although the risk of infection during CPNB is a major issue, the published literature has mainly focused on the conflicting evidence of the frequency of infectious complications associated with epidural anesthesia. Recent studies show that between 23 and 57% of peripheral nerve catheters may become colonized, with 0–3% resulting in localized infection. Severe infectious complications recently reported in the literature include psoas abscess complicating continuous femoral nerve blocks, axillary abscess and necrotizing fasciitis after continuous and single shot axillary nerve blocks, and thigh and interscalene abscesses after continuous popliteal sciatic and interscalene nerve blocks, respectively (table 1). An exogenous source of contamination is frequently suspected. The most frequently detected microorganism on the skin surface and in colonized catheter is Staphylococcus epidermidis, whereas Staphylococcus aureus is mainly reported in infections or abscess formation. Several risk factors, including appropriate patient selection (intensive care unit or trauma patients), catheter site insertion, prophylactic antibiotic use, local anesthetic solution contamination, and catheter duration, have been suspected to modify the risk of infection related to CPNB. The current recommendations to control infectious complications associated with CPNB are based on existing literature and guidelines for the prevention of epidural or intravascular catheter-related infection. The American Society for Regional Anesthesia and Pain Medicine guidelines on this topic have been published in Regional Anesthesia and Pain Medicine. These recommendations highlighted the importance of asepsis during regional anesthesia needle and catheter insertion, including handwashing, use of protective barriers (mask, gloves, gowns, and drapes), and skin disinfectants. The role of subcutaneous tunneling and of bacterial filters is still controversial. Guidelines for practice improvement must be built according to specific actual risk applied to each procedure and certainly cannot be extrapolated without some restrictions. CPNBs are increasing in popularity, and the incidence of infection associated with CPNB is thankfully rare. However, infectious complications will become undoubtedly more common. This review is to tell the reader what is actually known about risk factors specific to CPNBs.