Victor M. Zayas

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.

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.

The Incidence of Transient Neurologic Symptoms After Spinal Anesthesia with Mepivacaine

We prospectively evaluated 1273 patients who received spinal (or combined spinal-epidural [CSE]) anesthesia with 1.5% mepivacaine (plain, no glucose) for ambulatory surgery. We hypothesized that analysis of a large series of patients would confirm previous findings that isobaric 1.5% mepivacaine is not frequently associated with transient neurologic symptoms (TNS). Patients were contacted twice after the anesthetic, at days 1–4 and days 6–9. One-thousand-two-hundred-ten patients were successfully contacted postoperatively (95% follow-up rate). None of the patients had permanent neurologic sequelae from the anesthetic. None of the 372 CSE anesthetics was inadequate for surgery. Fourteen of 838 (1.7%) of the spinal anesthetics were inadequate. TNS, defined as the new onset of back pain that radiated bilaterally to buttocks or distally, occurred in 78 patients (6.4%; 95% confidence intervals 5.1%–8%). The mean age of patients who developed TNS (48 ± 14 yr) was older than that of patients without TNS (41 ± 16 yr) (P < 0.001). TNS was not influenced by gender or intraoperative position. The frequent success rate and infrequent rates of complications such as TNS and postdural puncture headache suggest that spinal anesthesia with mepivacaine is likely to be a safe and effective anesthetic for ambulatory patients.

Dose response relationships for isobaric spinal mepivacaine using the combined spinal epidural technique

UNLABELLED Mepivacaine, a local anesthetic with similar physiochemical properties to those of lidocaine, is an adequate alternative for patients undergoing ambulatory procedures, and is associated with a lower incidence of transient neurologic symptoms (TNS) than lidocaine. We studied the dose-response characteristics of isobaric intrathecal mepivacaine using the combined spinal epidural technique for patients undergoing ambulatory arthroscopic surgery of the knee. Seventy-five patients were randomized prospectively to receive one of three doses of isobaric mepivacaine for spinal anesthesia: 30 mg (2 mL 1.5%), 45 mg (3 mL 1.5%), or 60 mg (4 mL 1.5%). An observer, blinded to the dose, recorded sensory level to pinprick and motor response until resolution of the block. In addition, the incidence of TNS was determined. An initial intrathecal dose of 30 mg of isobaric mepivacaine 1.5% produced satisfactory anesthesia in 72% of ambulatory surgical patients undergoing unilateral knee arthroscopy with a significantly shorter duration of sensory (158 +/- 32 min) and motor blockade (116 +/- 38 min) than doses of 45 and 60 mg. An intrathecal dose of 45 mg produced satisfactory anesthesia in all patients with a shorter duration of sensory (182 +/-38 min) and motor blockade (142 +/- 37 min) than 60 mg of mepivacaine 1.5% (203 +/- 36 min and 168 +/- 36 min, respectively). The incidence of TNS was 7.4% overall (1.2%-13.6% confidence intervals), less than the rates previously reported after spinal anesthesia with lidocaine in ambulatory surgical patients undergoing knee arthroscopy. We conclude that mepivacaine can be used as an adequate alternative to lidocaine for ambulatory procedures. IMPLICATIONS This study evaluated the postoperative duration of spinal anesthesia after varying doses of isobaric mepivacaine and the incidence of transient radiating back and leg pain. We found that 45 mg of mepivacaine provided adequate anesthesia, a timely discharge, and a lower incidence of back pain than that previously reported after lidocaine spinals.

Postoperative Analgesia with Saphenous Block Appears Equivalent to Femoral Nerve Block in ACL Reconstruction

BackgroundAdequate pain control following anterior cruciate ligament reconstruction (ACL) often requires regional nerve block. The femoral nerve block (FNB) has been traditionally employed. Ultrasound application to regional nerve blocks allows for the use of alternatives such as the saphenous nerve block following ACL reconstruction.Questions/PurposesThis study evaluated postoperative analgesia provided by the subsartorial saphenous nerve block (SSNB) compared to that provided by the traditional FNB for patients undergoing ACL reconstruction with patellar tendon (bone–tendon–bone (BTB)) autografts.MethodsA randomized, blinded, controlled clinical trial was conducted using 80 ASA I–III patients, ages 16–65, undergoing ACL reconstruction with BTB. The individuals assessing all outcome measures were blinded to the treatment group. Postoperatively, all patients received cryotherapy and parenteral hydromorphone to achieve numeric rating scale pain scores less than 4. At discharge, patients were given prescriptions for oral opioid analgesics and a scheduled NSAID. Patients were instructed to complete pain diaries and record oral opioid utilization. Patients were contacted on postoperative days (POD) 1 and 2 to ascertain the level of patient satisfaction with the analgesic regimen.ResultsNo differences between the two groups were found. Patient demographics and postoperative pain scores at rest were not different. In addition, there was no difference in opioid use, as measured in daily oral morphine equivalents between groups. A small but statistically significant report of higher patient satisfaction with the FNB was found on POD 1 but not on POD 2.ConclusionThese data support our hypothesis that the SSNB provides similar and adequate postoperative analgesia when compared to the FNB, following arthroscopic ACL reconstruction with patellar tendon autograft.

Comparison of the transarterial axillary block and the ultrasound-guided infraclavicular block for upper extremity surgery: a prospective randomized trial.

Background and Objectives: The transarterial axillary block and the ultrasound-guided infraclavicular block are both effective methods of anesthetizing the upper extremity. This study compares these methods with respect to subjective postoperative dysesthesias, block adequacy, patient comfort, and patient satisfaction. Methods: Two hundred thirty-two patients were randomized to receive an ultrasound-guided infraclavicular block or a transarterial axillary block for upper extremity surgery. Block placement, motor and sensory testing, and block adequacy data were recorded. The subjects were contacted by a blinded research assistant at 2 and 10 days postoperatively to assess for the presence of dysesthesias and pain and to assess patient satisfaction. Results: The 2 techniques were similar with respect to block performance time and adequacy of the block for surgery. There was no significant difference between the blocks in terms of postoperative dysesthesias (23.9% in the axillary group vs 17.1% in the infraclavicular group at 2 days, P = 0.216, and 11.0% vs 6.31% at 10 days, P = 0.214). None of the dysesthesias were permanent. The infraclavicular block had a lower incidence of paresthesias during placement (P = 0.035) and was associated with less pain at the block site (P = 0.010 at 2 days, P = 0.002 at 10 days). More patients were willing to undergo the infraclavicular block as a future anesthetic when compared with the axillary block (P = 0.025 at 10 days). Conclusions: There is no significant difference between the 2 techniques in terms of adequacy for surgery and subjective postoperative dysesthesias. The ultrasound-guided infraclavicular block is associated with greater patient comfort and willingness to undergo the same anesthetic when compared with the transarterial axillary block.

Cervical spine disease is a risk factor for persistent phrenic nerve paresis following interscalene nerve block.

Abstract The use of interscalene blocks (ISBs) for shoulder surgery improves postoperative pain control, reduces recovery room times, and reduces overall hospital stays. The most common and potentially disabling adverse effect associated with ISBs is phrenic nerve paresis. Fortunately, persistent phrenic nerve paresis (PPNP) is rare. There are only 4 case reports of PPNP in the English literature. At our institution, we identified 9 cases of PPNP over a 9-year period, representing an incidence of 1 (0.048%) in 2069. In conducting a case-control series, we found that symptomatic cervical spine disease is a risk factor for the development of PPNP. Patients with PPNP had a significantly higher incidence of cervical spine disease (85.7%) compared with the control group (30.9%), P < 0.01. Persistent phrenic nerve paresis remains a perplexing complication of ISB, and many questions remain unanswered. Our data identify an important risk factor that can aid in the risk stratification of patients undergoing ISB.

Antiemetic Prophylaxis with Ondansetron for Post-discharge Nausea andVomiting after Hip Arthroscopy Performed under Neuraxial Anesthesia: AProspective, Randomized, Placebo-controlled Trial

Background: Post-Discharge Nausea and Vomiting (PDNV) remain common complaints after ambulatory surgery. This study investigated whether continuation of an anti-emetic regimen for two days postoperatively would reduce PDNV. Methods: A prospective, randomized placebo-controlled trial of 76 patients undergoing ambulatory hip arthroscopy was initiated. All patients received a spinal or combined spinal epidural and intravenous sedation. No intraoperative opioids were given. Prophylatic anti-emetics (dexamethasone, ondansetron) were given. Postoperatively, two groups either received oral placebo or ondansetron for two days. Results: On postdischarge day 1, nausea occurred in 54% of the placebo group and 46% of the oral ondansetron group (p=0.49). On postdischarge day 2 and 3, nausea occurred in 16% and 11% of the placebo group; 18% and 10% of the oral ondansetron group (p=0.84 and p=0.94), respectively. Conclusion: Postdischarge prophylactic oral ondansetron, administered for two days, did not reduce the incidence or severity of nausea in ambulatory hip arthroscopy patients.

Fatal Cerebral Swelling Associated with Scoliosis Surgery in Two Patients with Neuromuscular Scoliosis and Congenital Hydrocephalus: A Report of Two Cases

Patients with progressive neuromuscular scoliosis often undergo spinal fusion to prevent progression, improve sitting balance, and preserve pulmonary function1,2. These patients often have abnormalities in cerebrospinal fluid outflow, resulting in hydrocephalus and requiring ventricular shunting3. They also can have tethering of the spinal cord, which can restrict spinal cord excursion during correction of sagittal plane deformities4-6. These factors can predispose patients to cerebral swelling and brain injury during scoliosis surgery. We present two patients with neuromuscular scoliosis and ventriculoperitoneal (VP) shunts who developed acute, fatal cerebral swelling following spinal surgery. The Hospital for Special Surgery institutional review board approved waivers for both consent and HIPAA privacy rules since the patients met the appropriate criteria. Case 1. An eleven-year-old girl presented with progressive neuromuscular scoliosis. The patient’s congenital hydrocephalus had been managed with a VP shunt when she was two years old. A tethered cord release had been performed when she was five years old. At the age of eleven years, she presented with limited walking ability, inability to hold a standing position, and diminishing pulmonary function. A right thoracolumbar prominence was grossly evident on examination (Figs. 1-A and 1-B). Progressive lower-extremity weakness correlated with the increasing sagittal plane spinal deformity and may have been related to increasing compression of the conus medullaris or spinal cord over the apex of the thoracolumbar kyphosis. Fig. 1 Clinical photographs ( Figs. 1-A and 1-B) demonstrating spinal deformity (Case 1). Radiographs demonstrated a long right thoracolumbar scoliosis extending from T4 to L4 with a Cobb angle of 40° (Fig. 2-A). There was reversal of both normal thoracic kyphosis and lumbar lordosis with Cobb angle measurements of 20° of lordosis from T2 to T12, 28° of kyphosis from L1 to S1, and 57° of kyphosis at the …