Gregory A. Liguori

A prospective, randomized, controlled trial comparing ultrasound versus nerve stimulator guidance for interscalene block for ambulatory shoulder surgery for postoperative neurological symptoms.

BACKGROUND: Visualization with ultrasound during regional anesthesia may reduce the risk of intraneural injection and subsequent neurological symptoms but has not been formally assessed. Thus, we performed this randomized clinical trial comparing ultrasound versus nerve stimulator-guided interscalene blocks for shoulder arthroscopy to determine whether ultrasound could reduce the incidence of postoperative neurological symptoms. METHODS: Two hundred thirty patients were randomized to a standardized interscalene block with either ultrasound or nerve stimulator with a 5 cm, 22 g Stimuplex® insulated needle with 1.5% mepivacaine with 1:300,000 epinephrine and NaCO3 (1 meq/10 mL). A standardized neurological assessment tool (questionnaire and physical examination) designed by a neurologist was administered before surgery (both components), at approximately 1 wk after surgery (questionnaire), and at approximately 4–6 weeks after surgery (both components). Diagnosis of postoperative neurological symptoms was determined by a neurologist blinded to block technique. RESULTS: Two hundred nineteen patients were evaluated. Use of ultrasound decreased the number of needle passes for block performance (1 vs 3, median, P < 0.001), enhanced motor block at the 5-min assessment (P = 0.04) but did not decrease block performance time (5 min for both). No patient required conversion to general anesthesia for failed block, and patient satisfaction was similar in both groups (96% nerve stimulator and 92% ultrasound). The incidence of postoperative neurological symptoms was similar at 1 wk follow-up with 11% (95% CI of 5%–17%) for nerve stimulator and 8% (95% CI of 3%–13%) for ultrasound and was similar at late follow-up with 7% (95% CI of 3%–12%) for nerve stimulator and 6% (95% CI of 2%–11%) for ultrasound. The severity of postoperative neurological symptoms was similar between groups with a median patient rating of moderate. Symptoms were primarily sensory and consisted of pain, tingling, or paresthesias. CONCLUSIONS: Ultrasound reduced the number of needle passes needed to perform interscalene block and enhanced motor block at the 5 min assessment; however, we did not observe significant differences in block failures, patient satisfaction or incidence, and severity of postoperative neurological symptoms.

Transient Neurologic Symptoms after Spinal Anesthesia with Mepivacaine and Lidocaine

Background Spinal anesthesia with lidocaine is ideal for ambulatory surgery because of its short duration of action. However, transient neurologic symptoms (TNS) occur in 0–40% of patients. The incidence of TNS with mepivacaine, which has a similar duration of action, is unknown. Methods Sixty ambulatory patients undergoing knee arthroscopy received spinal anesthesia in a randomized, double‐blinded manner, with either 45 mg 1.5% mepivacaine or 60 mg 2% lidocaine. An L3‐L4 midline approach was used with a 27‐gauge Whitacre needle and a 20‐gauge introducer. The local anesthetic was injected over approximately 30 s with the aperture of the Whitacre needle in a cephalad direction. Two to 4 days after operation, each patient was questioned about the development of TNS. In addition, the two groups were compared for time to regression of sensory and motor blockade and time to discharge milestones. Results Three patients receiving lidocaine were lost to follow‐up. None of the 30 patients in the mepivacaine group developed TNS, whereas 6 of 27 (22%) in the lidocaine group did (P = 0.008). Time to regression to the L5 sensory level and to complete resolution of motor block were similar in both groups. The times to discharge milestones were also comparable. Conclusions The incidence of TNS is greater with 2% lidocaine than with 1.5% mepivacaine for patients having unilateral knee arthroscopy under spinal anesthesia. Mepivacaine seems to be a promising alternative to lidocaine for outpatient surgical procedures because of its similar duration of action. Further studies are warranted to determine the optimal dose of intrathecal mepivacaine for ambulatory surgery and the incidence of TNS with other doses and concentrations of intrathecal mepivacaine.

The use of metoprolol and glycopyrrolate to prevent hypotensive/bradycardic events during shoulder arthroscopy in the sitting position under interscalene block

Sudden profound hypotensive and/or bradycardic events (HBE) have been reported in >20% of patients undergoing shoulder arthroscopy in the sitting position under interscalene block anesthesia.Retrospective studies suggest that the administration of beta-blockers is safe and may decrease the incidence

Asystole and severe bradycardia during epidural anesthesia in orthopedic patients

IN a number of studies 1-3 and case reports, 4,5 researchers have described bradycardia and asystole during spinal anesthesia. Proposed physiologic mechanisms have been discussed, and clinical factors that contribute to these events, including hypoxemia 3 and lack of vigilance, 6-9 have been described. Factors associated with the development of bradycardia during spinal anesthesia have been studied by Carpenter et al. 2 and Liu and colleagues. 10 These include low resting heart rate, use of beta blockers, American Society of Anesthesiologists physical status 1, peak block height, and first degree atrio-ventricular block. In contrast, there has been little reported on the occurrence of bradycardia and asystole during epidural blockade. 11,12 This is a report of 7 cases of severe bradycardia and 5 cases of asystole that occurred during orthopedic surgery under epidural anesthesia during the past 9 yr at our institution. These include one case of asystole and one case of severe bradycardia that occurred in the post anesthesia care unit (PACU). Although this report does not provide data on the incidence of bradycardia, these individual cases provide the greatest experience on patterns of onset of acute bradycardia and asystole during epidural anesthesia yet published, and may provide insight into potential etiologic mechanisms.

Nerve localization techniques for interscalene brachial plexus blockade: a prospective, randomized comparison of mechanical paresthesia versus electrical stimulation.

Postoperative neurologic symptoms (PONS) are relatively common after upper extremity orthopedic surgery performed under peripheral neural blockade. In this study, we prospectively compared the incidence of PONS after shoulder surgery under interscalene (IS) block using the electrical stimulation (ES) or mechanical paresthesia (MP) techniques of nerve localization. For patients randomized to the MP group, a 1-in, 23-g long-beveled needle was placed into the IS groove to elicit a paresthesia to the shoulder, arm, elbow, wrist, or hand. For patients randomized to the ES group, a 5-cm, 22-g short-beveled insulated needle was placed into the IS groove to elicit a motor response including flexion or extension of the elbow, wrist, or fingers or deltoid muscle stimulation at a current between 0.2 and 0.5 mA. Each IS block was performed with 50–60 mL of 1.5% mepivacaine containing 1:300,000 epinephrine and 0.1meq/L sodium bicarbonate. Two-hundred-eighteen patients were randomized between the two groups. One patient was lost to follow-up. Twenty-five patients (23%) in the ES group experienced paresthesia during needle insertion. The incidence of PONS using the ES technique was 10.1% (11/109), whereas the incidence with the MP technique was 9.3% (10/108) (not significant). The PONS lasted a median duration of 2 mo, and symptoms in all patients resolved within 12 mo. The success rate, onset time, and patient satisfaction were also comparable between groups. We conclude that the choice of nerve localization technique can be made based on the patient’s and anesthesiologist’s comfort and preferences and not on concern for the development of PONS.

Two cases of a wrong-site peripheral nerve block and a process to prevent this complication

Objective: The purpose of this study was to develop a system to prevent laterality errors while performing peripheral nerve blockade. Case Report: The report depicts 2 cases of peripheral nerve blocks being performed on the wrong (nonoperative) extremity. An analysis of the circumstances in each case reveals distractions, schedule changes, and communication breakdown, which contributed to the error. A protocol to prevent these errors from occurring in the future, based on the Joint Commission on Accreditation of Healthcare Organizations guidelines, to eliminate “wrong-site” surgical procedures is developed and discussed. Conclusions: The anesthesiologist plays an important role in preventing wrong-site peripheral nerve blockade and surgery. The protocol developed for “Pre-Anesthetic Site Verification” as a supplement to our preoperative site verification policy is invaluable in preventing wrong-site anesthesia and surgery.

Disclosure of Risks Associated With Regional Anesthesia: A Survey of Academic Regional Anesthesiologists

Background and Objectives: In view of the relatively few large studies available to estimate the rates of complications following regional anesthesia, we aimed to identify and quantify the risks that academic regional anesthesiologists and regional anesthesia fellows disclose to their patients before performing central and peripheral nerve blockade. Methods: We asked 23 North American regional anesthesia fellowship program directors to distribute a questionnaire to the regional anesthesiologists and regional anesthesia fellows at their institutions. The questionnaire was designed to capture the risks and corresponding incidences that are routinely disclosed to patients before performing the most common central and peripheral nerve block techniques. Results: The total number of respondents was 79 from 12 different institutions. Fifty-eight (74%) respondents disclose risks of regional anesthesia in order to allow their patients to make an informed choice, whereas 20 (26%) disclose risks for medicolegal reasons. For central neural blockade, the most commonly disclosed risks are headache, local pain/discomfort, and infection. For peripheral nerve blockade, the most commonly disclosed risks are transient neuropathy, local pain/discomfort, and infection. For both central and peripheral nerve blockade, the risks most commonly disclosed are also those with the highest-reported incidences. Conclusions: The risks of regional anesthesia most commonly disclosed to patients by academic regional anesthesiologists and regional anesthesia fellows are benign in nature and occur frequently. Severe complications of regional anesthesia are far less commonly disclosed. The incidences of severe complications disclosed by academic regional anesthesiologists and their fellows can be inconsistent with those cited in the contemporary literature.

One-Year Experience with Day-of-Surgery Pregnancy Testing Before Elective Orthopedic Procedures

BACKGROUND: Elective surgery is generally postponed in pregnancy. A policy of testing for urine human chorionic gonadotropin (hCG) in all women of childbearing age on the day of surgery was initiated at an elective orthopedic surgery facility. This is a retrospective report of our 1 yr experience and the associated costs. METHODS: Records were reviewed from January 3, 2005, through January 2, 2006, to determine the number of urine hCG tests performed, and the disposition of all patients with a positive result. Costs were calculated using the charges for testing supplies and laboratory labor. RESULTS: During the first year of policy implementation, 2588 of 2595 women of childbearing age underwent urine hCG testing. Five patients had a positive result, and surgery was cancelled. Of these five, three were previously unrecognized pregnancies, one an unrecognized asymptomatic ectopic pregnancy, and one a false-positive result in a perimenopausal woman. Three other women had a “weak positive” urine result, followed by a negative serum hCG. Surgery proceeded in all three. The calculated cost was

Possible bupivacaine toxicity after intraarticular injection for postarthroscopic analgesia of the knee: implications of the surgical procedure.

5.03 per urine test, and

The Incidence of Transient Neurologic Symptoms After Spinal Anesthesia with Mepivacaine

3273 for each true positive result. CONCLUSIONS: A policy of routinely performing urine hCG pregnancy tests in women of childbearing age on the day of surgery was effective in detecting unrecognized pregnancy. This resulted in a postponement of elective surgery in all cases. Of 2588 women tested, one had surgery postponed because of a false-positive result. The cost of