Pulmonary Function Changes After Interscalene Brachial Plexus Anesthesia with 0.5% and 0.75% Ropivacaine

Postoperative neurologic symptoms in the operative arm after shoulder surgery with interscalene blockade: a systematic review

OBJECTIVE

Postoperative neurologic symptoms (PONS) in the operative arm are important complications of shoulder surgery and interscalene blockade (ISB). This systematic review aimed to compare the risk of PONS between ISB and other techniques, and the relative safety of different agents used in ISB.

METHODS

Our systematic review followed Cochrane review methodology and was registered in PROSPERO. A search of MEDLINE (Ovid), EMBASE (Ovid), and CENTRAL (Wiley) from inception to June 2020 was completed. We included randomized or quasi-randomized trials of patients (> five years old) undergoing shoulder surgery with any ISB technique as an intervention, compared with any other nonregional or regional technique, or ISB of alternate composition or technique. The primary outcome was PONS (study author defined) assessed a minimum of one week after surgery.

RESULTS

Fifty-five studies totalling 6,236 participants (median, 69; range, 30-910) were included. Another 422 otherwise eligible trials were excluded because PONS was not reported. Heterogeneity in when PONS was assessed (from one week to one year) and the diagnostic criteria used precluded quantitative meta-analysis. The most common PONS definition, consisting of one or more of paresthesia, sensory deficit, or motor deficit, was only used in 16/55 (29%) trials. Risk of bias was low in 5/55 (9%) trials and high in 36/55 (65%) trials, further limiting any inferences.

CONCLUSION

These findings highlight the need for a standardized PONS outcome definition and follow-up time, along with routine, rigorous measurement of PONS in trials of ISB.

STUDY REGISTRATION

PROSPERO (CRD42020148496); registered 10 February 2020.

Postoperative Pain Management and the Incidence of Ipsilateral Shoulder Pain After Thoracic Surgery at an Australian Tertiary-Care Hospital: A Prospective Audit

OBJECTIVES

Ipsilateral shoulder pain (ISP) is a common but variably occurring (42%-85%) complication after thoracic surgery. Multiple potential treatments, including upper limb blocks, intrapleural local anaesthetic infiltration, and systemic opioids, have undergone trials, with limited efficacy. Phrenic nerve infiltration is a potential intervention that may prevent ISP. The aim of this study was to assess the incidence and severity of ISP after thoracic surgery at the authors' institution, where phrenic nerve infiltration is commonly used.

DESIGN

Observational cohort study.

SETTING

A single- center study in a tertiary referral center in Brisbane, Australia.

PARTICIPANTS

This study comprised all adult patients undergoing thoracic surgery at a tertiary- care referral center from May to July 2018.

MEASUREMENTS AND MAIN RESULTS

Surgical procedures were divided into open thoracotomy, video-assisted thoracic surgery (VATS) and VATS-guided mini-thoracotomy. The primary outcome was a comparison of incidence of ISP among the 3 types of surgical procedures. Data were analyzed using Stata (StataCorp), with significance testing by Kruskal-Wallis equality of populations rank test. A p value of < 0.05 was deemed significant. Sixty thoracic surgeries were performed during the audit period. Nineteen patients had thoracotomies performed for lobectomy or pneumonectomy, all of whom received phrenic nerve infiltration. The incidence of moderate-to-severe ipsilateral shoulder pain among the thoracoctomy cohort was 15.8% (3/19). Of the 36 VATS procedures audited, 7 patients (19.4%) received infiltration of their phrenic nerve, none of whom reported postoperative ISP. Of the remaining twenty-nine patients who did not receive phrenic nerve infiltration, there were 4 cases of moderate-to-severe ipsilateral shoulder pain (11.1%). Four of the 5 patients (80%) who underwent VATS-guided mini-thoracotomies received phrenic nerve infiltration intraoperatively. Three patients reported moderate-to-severe ISP and of these 3 patients, 2 patients had phrenic nerve infiltration, and 1 patient did not receive infiltration. Overall, there were no statistically significant differences in rest or dynamic pain scores across the surgical groups at any time point. Mann-Whitney test revealed that the participants with ISP were significantly older than those without ISP (p = 0.006). However, there were no significant differences in sex or body mass index between those with and without ISP.

CONCLUSION

The authors observed a lower (15.8%) incidence of moderate-to-severe ISP among their thoracotomy patients than reported in prior literature. Injection of local anesthetic into the phrenic nerve fat pad at the level of the diaphragm appeared to be an effective and safe surgical intervention that may eliminate a significant cause of ISP. None of the VATS patients who received phrenic nerve infiltration experienced ISP. Postoperative pain in VATS is expected to be reduced by avoiding the use of a rib spreader, severing of the intercostal nerves, and division of muscle tissue, which may account for the lower observed rates of ISP in the VATS cohort who did not receive phrenic nerve infiltration. Further randomized controlled trials are warranted to establish if patients undergoing various VATS procedures benefit from this intervention.

Incidence of vocal cord paresis following ultrasound-guided interscalene nerve block: An observational cohort study

BACKGROUND

Interscalene brachial plexus block (IBPB) has become a standard practice for perioperative analgesia for shoulder procedures. However, several side effects may occur owing to its anatomic location. We have chosen to evaluate vocal cord paresis and dysphonia following interscalene blocks.

METHODS

After IRB approval, eight patients undergoing arthroscopic shoulder procedures were recruited into this prospective cohort study. Following informed consent, vocal cords were assessed by standardized fiberoptic evaluation. Subsequently, IBPB was performed under ultrasound (US) guidance. Patients were re-evaluated for vocal cord changes by a repeat fiberoptic assessment one hour following IBPB. Our primary outcome measure was incidence of vocal cord immobility.

RESULTS

No patients had diminished vocal cord motion, dysphonia, or dysphagia.

CONCLUSIONS

Although larger studies are required to determine the true incidence of vocal cord paresis following US-guided IBPB, our results suggest that incidence of unwanted nerve blockade other than brachial plexus is much lower than that previously described.

Review of the evidence: best analgesic regimen for shoulder surgery

Multimodal pain management has been advocated in patients experiencing acute pain after surgical procedures due to tissue damage and the subsequent inflammatory response. For patients undergoing shoulder surgeries, studies have definitively shown that interscalene blocks (ISBs) via single-injection or continuous infusion can reduce the total opioid consumption and can lower pain scores after surgery. In some cases, ISBs can be used as the sole anesthetic during shoulder surgeries and spare patients of receiving general anesthesia. However, clinicians should be fully aware of potential pulmonary complications of ISBs and weigh the risk-benefit ratio in patients with limited pulmonary reserve.

Phrenic Nerve Palsy and Regional Anesthesia for Shoulder Surgery

Regional anesthesia has an established role in providing perioperative analgesia for shoulder surgery. However, phrenic nerve palsy is a significant complication that potentially limits the use of regional anesthesia, particularly in high-risk patients. The authors describe the anatomical, physiologic, and clinical principles relevant to phrenic nerve palsy in this context. They also present a comprehensive review of the strategies for reducing phrenic nerve palsy and its clinical impact while ensuring adequate analgesia for shoulder surgery. The most important of these include limiting local anesthetic dose and injection volume and performing the injection further away from the C5–C6 nerve roots. Targeting peripheral nerves supplying the shoulder, such as the suprascapular and axillary nerves, may be an effective alternative to brachial plexus blockade in selected patients. The optimal regional anesthetic approach in shoulder surgery should be tailored to individual patients based on comorbidities, type of surgery, and the principles described in this article.

Continuous interscalene brachial plexus nerve block prolongs unilateral diaphragmatic dysfunction

BACKGROUND AND OBJECTIVES

Single interscalene blocks (ISB) impair pulmonary function (<24h). We hypothesized that continuous ISBs would prolong pulmonary dysfunction until h48 compared with a single ISB. We compared the time course of spirometric and diaphragmatic dysfunction following single or continuous ISBs.

METHODS

We prospectively included consecutive adult patients scheduled to undergo shoulder surgery under standard general anaesthesia with single (n=30) or continuous (n=31) ISB. Before ISB (baseline), spirometric tests were recorded and the diaphragm course was evaluated with a B-mode ultrasound technique every 12h until h48. ISBs were performed with 15mL 0.5% ropivacaine using an ultrasound technique approach. The continuous group received the same bolus followed by 0.2% ropivacaine 5mL·h^-1 (48h). The primary end point was the reduction (> 25% from baseline) of forced vital capacity (FVC) over the study period (48h).

RESULTS

Patient characteristics were similar in both groups. Thirty minutes after blocks in the PACU, all patients demonstrated a similar and significant unilateral diaphragm paralysis (< 25% from baseline). For the primary end point (FVC), no significant difference was observed between groups over the study period. A difference between single and continuous groups was observed at h24 for: FVC (-25%, P=0.038), FEV1s (-24%, P=0.036), diaphragmatic course (-26%, P=0.02), while no differences for other time points (h0-h48) were noted. Clinical respiratory evaluations (respiratory rate, SpO₂, supplementary nasal O₂), postoperative pain scores and additional opioid consumption were similar between groups.

CONCLUSION

Over infusion, continuous ISB did not significantly prolong unilateral phrenic paresis and demonstrated a limited pulmonary impact.

The effect of mepivacaine on swine lingual, pulmonary and coronary arteries

Background

Although mepivacaine has a known biphasic action on the aortic and coronary artery in several animal species, its effects on the lingual and pulmonary artery are not well understood and it is not yet known whether mepivacaine produces vasoconstriction in these vessels. The present study aims to investigate the direct effects of mepivacaine on swine lingual, pulmonary and coronary arterial endothelium-denuded rings.

Methods

Artery rings were perfused with isotonic 40 mM KCl until a stable constricted plateau was reached. The rings were then perfused with isotonic 40 mM KCl plus a particular concentration of mepivacaine (0.4 μM, 4.0 μM, 40 μM, 0.4 mM and 4.0 mM). The isometric tension strengths in each experiment were normalized to the strength of the isometric tension immediately before mepivacaine perfusion and expressed as a percentage.

Results

Mepivacaine at 0.4 to 40 μM did not significantly alter 40 mM KCl-induced contraction in the lingual, pulmonary and coronary arterial rings. In contrast, mepivacaine at 4 mM produced attenuated vasoconstriction in the lingual, pulmonary and coronary arterial compared with isotonic 40 mM KCl.

Conclusions

Mepivacaine produced vasoconstriction at lower concentrations, followed by attenuated vasoconstriction at higher concentrations on swine lingual, pulmonary and coronary arterial endothelium-denuded rings. Mepivacaine (4 μM) appeared to increase isotonic 40 mM KCl-induced contraction, followed by attenuated vasoconstriction at 4 mM. Dentists using 3 % mepivacaine should take into consideration that the risk of complications may be increased if more than six mepivacaine cartridges are used in dental treatment or minor surgery, or if over 15 ml of mepivacaine is administered to a patient with cardiovascular complications during general anesthesia for oral maxillofacial surgery.

Preoperative evaluation of the patient with pulmonary disease

BACKGROUND AND OBJECTIVES

In daily clinical practice, pulmonary complications related to surgical procedure are common, increasing the morbidity and mortality of patients. Assessment of the risk of pulmonary complications is an important step in the preoperative evaluation. Thus, we review the most relevant aspects of preoperative assessment of the patient with lung disease.

CONTENT

Pulmonary risk stratification depends on clinical symptoms and patient's physical status. Age, preexisting respiratory diseases, nutritional status, and continued medical treatment are usually more important than additional tests. Pulmonary function tests are of great relevance when high abdominal or thoracic procedures are scheduled, particularly when lung resection are considered.

CONCLUSION

Understanding the perioperative evaluation of the potential risk for developing pulmonary complication allows the medical team to choose the adequate anesthetic technique and surgical and clinical care required by each patient, thereby reducing adverse respiratory outcomes.

A clinical comparison of vertical infraclavicular brachial plexus block using 0.75% or 0.5% ropivacaine for upper limb surgery

BACKGROUND

We performed a prospective, double blind study to compare the clinical effect of vertical infraclavicular brachial plexus block produced by 0.75% vs 0.5% ropivacaine for upper limb surgery.

METHODS

We included 80 patients receiving upper limb surgery under infraclavicular brachial plexus block. The infraclavicular brachial plexus block was performed via the vertical technique with 30 ml of 0.75% or 0.5% ropivacaine. By observation, we determined nerve type was stimulated and scored the level of sensory block and motor block. The quality of blocks was assessed intra-operatively. The duration of sensory block and motor block and their complications were assessed.

RESULTS

There were no significant differences in the frequency of stimulated nerve type, evolution of sensory and motor block quality, or success of block. There were no significant differences in the duration of sensory block and motor block. Vascular puncture was noted in 1 patient in the 0.75% ropivacaine.

CONCLUSIONS

Both the 0.75% and 0.5% ropivacaine had similar effects in the vertical infraclavicular brachial plexus block.

Symptomatic phrenic nerve palsy after supraclavicular block in an obese man

Regional anesthesia has an expanding role in upper extremity surgery. Brachial plexus blocks offer several advantages including providing effective analgesia, reducing narcotic requirements, and facilitating ambulatory care surgery. Despite the popularity of nerve blocks, the surgeon must not forget the complications associated with regional anesthesia. This article describes a case of symptomatic phrenic nerve palsy after supraclavicular brachial plexus block in an obese man. A 46-year-old obese man underwent a left-sided supraclavicular block in preparation for decompression of Guyon's canal for ulnar mononeuropathy at the wrist. The patient experienced acute-onset dyspnea, chest discomfort, and anxiety, and physical examination demonstrated reduced breath sounds in the left hemithorax. Chest radiographs documented elevation of the left hemidiaphragm consistent with an iatrogenic phrenic nerve palsy. The patient was admitted for 23-hour observation and underwent an uncomplicated ulnar nerve decompression under Bier block anesthesia 1 week later. No long-term sequelae have been identified; however, there was a delay in surgical care, admission to the hospital, and transient pulmonary symptoms. We attribute this complication to significant abdominal obesity causing compromised pulmonary reserve and poor tolerance of transient hemidiaphragmatic paresis. In recent studies, waist circumference and abdominal height were inversely related to pulmonary function. We suspect that the incidence of symptomatic phrenic nerve palsy associated with brachial plexus blocks will increase as the prevalence of obesity increases in this country.

Upper extremity regional anesthesia: essentials of our current understanding, 2008

Brachial plexus blockade is the cornerstone of the peripheral nerve regional anesthesia practice of most anesthesiologists. As part of the American Society of Regional Anesthesia and Pain Medicine's commitment to providing intensive evidence-based education related to regional anesthesia and analgesia, this article is a complete update of our 2002 comprehensive review of upper extremity anesthesia. The text of the review focuses on (1) pertinent anatomy, (2) approaches to the brachial plexus and techniques that optimize block quality, (4) local anesthetic and adjuvant pharmacology, (5) complications, (6) perioperative issues, and (6) challenges for future research.

Ipsilateral shoulder pain after thoracotomy surgery

BACKGROUND AND OBJECTIVE

Analgesics and anaesthetics have diverse synaptic actions that nonetheless have a common net inhibitory action on neuronal discharge. It is puzzling, therefore, that these two classes of compounds have fundamentally different affects, one blocking pain and the other consciousness. Indeed, beyond the isolated synapse, little is known of the larger scale mechanisms that mediate actual function, for example, transient neuronal assemblies. It was hypothesized that the two classes of drugs might have, respectively, differential effects on transient activation of these assemblies of neurons working together.

METHODS

Hippocampal tissue from juvenile Wistar rats was used for in vitro optical imaging with voltage-sensitive dyes and simultaneous field potential recordings. The response to paired pulse stimulation of the hippocampus was recorded in the presence and absence of two types of analgesic (morphine and gabapentin) and two types of anaesthetic (thiopental and propofol).

RESULTS

Optical imaging and electrophysiology used in parallel yield quite different results. Most consistently, the imaging technique was able to detect an enhanced period of activation following anaesthetic, but not analgesic application. This effect was not readily seen from electrophysiology field potential recordings.

CONCLUSIONS

These findings suggest that, irrespective of the effects of the two drug classes at a synaptic level, the dynamics of transient neuronal assemblies are modified selectively by anaesthetics and not analgesics.

High volume and low concentration of anaesthetic solution in the perivascular interscalene sheath determines qualityof block and incidence of complications

BACKGROUND AND OBJECTIVE

In the perivascular sheath of the brachial plexus, the volume of anaesthetic solution determines the quality of anaesthetic cover. Fibrous septa may divide the perivascular space into compartments, leading to inadequate diffusion of the anaesthetic solution. The aim of our study was to obtain good anaesthesia and less complications using high volume of low concentration anaesthetic solution, overcoming the obstacle of the septa with a double approach to the scalene sheath.

METHODS

Sixty patients scheduled for shoulder capsuloplasty received both Winnie interscalene brachial plexus block and Pippa proximal cranial needle approach. The patients were randomly assigned to two groups. A constant dose of local anaesthetic was administered to each group: Group I (30 patients) received high volume (60 mL of anaesthetic solution) and Group II (30 patients) received low volume of solution (30 mL of anaesthetic solution). Sensory and motor block in the upper limb and complications were evaluated.

RESULTS

In all the patients the quality of anaesthesia obtained at the surgical site was excellent. In Group I also the areas supplied by the medial cutaneous nerves of the arm and forearm, ulnar, median and radial nerves were blocked (P < 0.002). Complications were only observed in Group II and consisted of bradycardia and hypotension (66% of the patients) and phrenic nerve paresis (27% of the patients).

CONCLUSIONS

The lower concentration of the anaesthetic solution avoids complications while increased volume provides good analgesic cover. The combination of the Winnie interscalene plexus block and the Pippa proximal cranial needle approach should contribute to fill up the scalene sheath overcoming the septa obstacles.

A supraomohyoidal plexus block designed to avoid complications

Interscalene blocks of the brachial plexus are used for surgery of the shoulder and are frequently associated with complications such as temporary phrenic block, Horner syndrome or hematoma. To minimize the risk of these complications, we developed an approach that avoids medially directed needle advancement and favors spread to lateral regions only: the supraomohyoidal block. We tested this procedure in 11 cadavers fixed by Thiel's method. The insertion site is at the lateral margin of the sternocleidomastoid muscle at the level of the cricoid cartilage. The needle is inserted in the axis of the plexus with an angle of approximately 35 degrees to the skin, and advanced in lateral and caudal direction. Distribution of solution was determined in ten cadavers after bilateral injection of colored solution (20 and 30 ml) and followed by dissection. In an eleventh cadaver, computerized tomography and 3D reconstruction after radio contrast injection was performed. In additional five cadavers we performed Winnie's technique with bilateral injection (20 and 30 ml). Concerning the supraomohyoidal block the injection mass reached the infraclavicular region surrounded all trunks of the brachial plexus in the supraclavicular region and the suprascapular nerve in all cases. The solution did not spread medially beyond the lateral margin of the anterior scalene muscle into the scalenovertebral triangle. Therefore, phrenic nerve, stellate ganglion, laryngeal nerve nor the vertebral artery were exposed to the injected solution. Distribution was comparable with the use of 20 and 30 ml of solution. Injections on five cadavers performing the interscalene block of Winnie resulted in an extended spread medially to the anterior scalene muscle. We conclude that our method may be a preferred approach due to its safety, because no structures out of interest were reached. Solution of 20 ml is suggested to be enough for a successful block.

Interscalene Brachial Plexus Block with Bupivacaine and Ropivacaine in Patients with Chronic Renal Failure: Diaphragmatic Excursion and Pulmonary Function Changes

In this randomized, double-blind study, we compared the anesthetic characteristics and pulmonary function changes of 0.33% bupivacaine and 0.33% ropivacaine used for interscalene brachial plexus (IBP) anesthesia in patients with chronic renal failure. Forty-two patients undergoing IBP anesthesia for creation of arteriovenous fistulas were randomly allocated to receive either 30 mL of 0.33% bupivacaine (Group B) or 0.33% ropivacaine (Group R). Block onset time, diaphragmatic excursion (ultrasonographic evaluation), and free plasma concentrations of bupivacaine and ropivacaine were evaluated. Negative motion or immobility of the ipsilateral hemidiaphragm and a decrease of >10 mm in positive motion were defined as diaphragmatic paresis. The pulmonary function variables were measured by bedside spirometry equipment. Seven patients needed supplemental local anesthetic, one with total spinal block; these patients were excluded from the study. The success rate was 80.9%. Block quality was similar in the two groups. Ipsilateral hemidiaphragmatic excursion was decreased in both groups compared with baseline values (P < 0.05). Diaphragmatic paresis was identified in 10 of 16 patients and 8 of 18 patients in Groups B and R, respectively (P > 0.05). Pulmonary function significantly decreased from baseline in both groups (forced vital capacity (FVC) 30%, forced expiratory volume at 1 second (FEV(1)) 32%, and peak expiratory flow (PEF) 31% in Group B and FVC 17%, FEV(1) 17%, and PEF 5% in Group R) (P < 0.001). The decreases in Group B were larger than those in Group R (P < 0.05). Three patients in Group B and one in Group R had mild respiratory problems (P > 0.05). Concentrations of bupivacaine and ropivacaine were below toxic levels rather than "normal range." We conclude that pulmonary function decreased more after IBP with 0.33% bupivacaine than with 0.33% ropivacaine.

Anaesthetic Agents for Advanced Regional Anaesthesia

Interest in the use of regional anaesthesia, particularly peripheral nerve blocks (PNBs) and continuous PNBs, has increased in recent years. Accompanying this resurgence in interest has been the development of new local anaesthetics and additives designed to enhance block duration and quality. This manuscript provides a literature-based review on accepted uses of local anaesthetics and adjuncts for a variety of regional anaesthesia techniques. A brief review of local anaesthetic pharmacodynamics describes the action of these drugs in preventing nerve depolarisation, thus blocking nerve impulses. Toxic adverse effects of local anaesthetics, specifically CNS and cardiac manifestations of excessive local anaesthetic blood concentrations and the direct neurotoxic properties of local anaesthetics, are discussed generally and specifically for many commonly used local anaesthetics. Clinically useful ester and amide local anaesthetics are evaluated individually in terms of their physical properties and toxic potential. How these properties impact on the clinical uses of each local anaesthetic is explored. Particular emphasis is placed on the long-acting local anaesthetic toxic potential of racemic bupivacaine compared with levobupivacaine and ropivacaine, which are both levorotatory stereoisomers. Guidelines for using ropivacaine and mepivacaine, based on the authors' experience using advanced regional anaesthesia in a busy practice, is provided. Finally, epinephrine (adrenaline), clonidine and other local anaesthetic additives and their rationale for use is covered along with other future possibilities.

Interscalene brachial plexus anesthesia and analgesia for open shoulder surgery: a randomized, double-blinded comparison between levobupivacaine and ropivacaine

We compared the onset time and quality of interscalene brachial plexus block produced with levobupivacaine and ropivacaine in 50 patients undergoing open shoulder surgery randomly allocated to receive 30 mL of 0.5% levobupivacaine (n = 25) or 0.5% ropivacaine (n = 25) injected through a 20-gauge catheter placed into the interscalene sheath using a 18-gauge insulated and stimulating Tuohy introducer. The block was also prolonged after surgery using a patient-controlled interscalene analgesia with 0.125% levobupivacaine or 0.2% ropivacaine, respectively (basal infusion rate, 6 mL/h; bolus, 2 mL; lockout period, 15 min; maximum boluses per hour, three). Three patients (two with levobupivacaine [8%] and one with ropivacaine [4%]) failed to achieve surgical block within 45 min after the injection and were excluded. The onset time of surgical block was 20 min (10-40 min) with levobupivacaine and 20 min (5-45 min) with ropivacaine (P = 0.53). Rescue intraoperative analgesia (0.1 mg of fentanyl IV) was required in eight patients in each group (34%) (P = 0.99). Forty-two patients completed the 24-h postoperative infusion (22 with levobupivacaine and 20 with ropivacaine). Postoperative analgesia was similarly effective in both groups. Total consumption of local anesthetic infused during the first 24 h was 147 mL (144-196 mL) with levobupivacaine and 162 mL (144-248 mL) with ropivacaine (P = 0.019), with a ratio between boluses received and requested of 0.8 (0.4-1.0) and 0.7 (0.4-1.0), respectively (P = 0.004). The degree of motor block of the operated limb was deeper with levobupivacaine than ropivacaine when starting postoperative analgesia; however, no further differences in degree of motor function were observed between the two groups. We conclude that 30 mL of levobupivacaine 0.5% induces an interscalene brachial plexus anesthesia of similar onset and intensity as the one produced by the same volume and concentration of ropivacaine. Postoperative interscalene analgesia with 0.125% levobupivacaine results in similar pain relief and recovery of motor function with less volume of local anesthetic than with 0.2% ropivacaine.

IMPLICATIONS

This prospective, randomized, double-blinded study demonstrates that 30 mL of 0.5% levobupivacaine produces an interscalene brachial plexus block of similar onset and quality as the one produced by the same volume of 0.5% ropivacaine. When prolonging the block after surgery, 0.125% levobupivacaine provides adequate pain relief and recovery of motor function after open shoulder surgery, with less volume infused during the first 24 h after surgery than 0.2% ropivacaine.

Perioperative interscalene blockade: an overview of its history and current clinical use

Use of single-dose and continuous interscalene brachial plexus block (ISB) are gaining widespread popularity. When compared with general anesthesia, ISB has been reported to provide superior postoperative analgesia with fewer side effects, and it is associated with greater patient satisfaction. Anatomical landmarks are readily identifiable, which contributes to the ease of performing this block. In the future, we anticipate increased use of continuous interscalene catheters or injection of biodegradable local anesthetic impregnated microspheres to provide prolonged perioperative outpatient analgesia.

Respiratory complications associated with anesthesia

Adverse pulmonary outcomes that follow anesthesia and surgery are often attributed to anesthesia care. PPCs are a significant concern for anesthesia caregivers because they use drugs and techniques that temporarily decrease lung volume, impair airway reflexes, limit immune function, and depress secretion mobilization. A significant component of perioperative risk derives from the surgical site, postoperative pain, and effects of pharmacologic pain management. Rapidly evolving surgical and anesthesia techniques and the introduction of newer pharmaceutical agents make it difficult to identify best practice from retrospective experience reported in the perioperative literature. Prospective studies that deal with specific patient populations, incomparable patient groups or techniques, and unique practice bias have limited validity of claims regarding several promising approaches to perioperative risk reduction. In the absence of clear scientific principles, a perioperative pulmonary risk management strategy for the early part of this century is based on the consensus practice of informed clinicians (Box 4).

Ropivacaine 7.5 mg/ml versus bupivacaine 5 mg/ml for interscalene brachial plexus block--a comparative study

We investigated ropivacaine 75 mg/ml in comparison with bupivacaine 5 mg/ml in patients receiving interscalene brachial plexus block (ISB) and general anaesthesia. In this randomized, double-blind, prospective clinical trial, each patient received an ISB block according to the technique originally described by Winnie and a catheter technique as per Meier. The rapidity of onset and the quality of sensory and motor block were determined. After general anaesthesia had been induced further parameters evaluated were consumption of local anaesthetic, opioid and neuromuscular blocking drug. After arrival in the recovery room, the patients were assessed for intensity of pain using a visual analog scale (VAS). One hundred and twenty patients were included in the study. The onset and development of sensory block was similar in both groups. Development and quality of motor block was also nearly identical for both local anaesthetics. Consumption of neuromuscular blocking drug and opioid did not differ between ropivacaine and bupivacaine. In the recovery room the mean pain score was less than 25 in both groups. There were no significant differences in terms of onset and quality of sensory or motor block during the intraoperative and early postoperative period. In addition we did not identify any side-effects related to the administration of the local anaesthetics. Ropivacaine 7.5 mg/ml and bupivacaine 5mg/ml proved to be nearly indistinguishable when administered for interscalene brachial plexus block.