Paravertebral blocks reduce the risk of postoperative urinary retention in inguinal hernia repair.

PURPOSE: Inguinal hernia repair and general anesthesia (GA) are known risk factors for urinary retention. Paravertebral blocks (PVBs) have been utilized to facilitate enhanced recovery after surgery. We evaluate the benefit of incorporating PVBs into our anesthetic technique in a large cohort of ambulatory patients undergoing inguinal hernia repair. METHODS: Records of 619 adults scheduled for ambulatory inguinal hernia repair between 2010 and 2015 were reviewed and categorized based on anesthetic and surgical approach [GA and open (GAO), GA and laparoscopic (GAL), PVB and open (PVBO), and GA/PVB and open (GA/PVBO)]. Patients were excluded for missing data, self-catheterization, chronic opioid tolerance, and additional surgical procedures coinciding with hernia repair. Risk factors associated with the primary outcome of urinary retention were examined using logistic regression. RESULTS: PVBO (n = 136) had significantly lower odds than GAO of experiencing urinary retention (odds ratio 0.16; 95% CI 0.05-0.51); overall (P < .01), with 4.4% (n = 6) of the patients in the PVBO group having urinary retention versus 22.6% (n = 7) with GAO. Expressed as intravenous morphine equivalences, the PVBO group had the lowest median opioid use (5 mg), followed by GA, PVB, and open (7.5 mg); GAO 25 mg; and GAL 25 mg. Also, 30% (n = 41) of the PVBO group required no opioid analgesia in the postanesthesia care unit. CONCLUSIONS: PVBs as the primary anesthetic or an adjunct to GA is the preferred anesthetic technique for open inguinal hernia repair as it facilitates enhanced recovery after surgery by decreasing risk of urinary retention, opioid requirements, and length of stay.

Three-dimensional ultrasound-assisted popliteal catheter placement revealing aberrant anatomy: implications for block failure.

BACKGROUND: The current means of introducing continuous sciatic catheters include nerve stimulation, with or without catheter stimulation techniques. More recently, ultrasound has been utilized to facilitate catheter placement. METHODS: This case represents a stimulating catheter-guided continuous block facilitated by three-dimensional ultrasound, which revealed aberrant anatomy with proximal and wide bifurcation of the sciatic nerve with implications for block failure. RESULTS: Before ultrasound imaging secondary failures were attributed to catheter misplacement or dislodgement. CONCLUSION: Because of this case observation, our current practice is to use ultrasound confirmation of the bifurcation of the nerve of all popliteal catheter placements, particularly catheters placed in patients having ambulatory procedures to prevent secondary failure of catheters at home.

Interscalene brachial plexus block with continuous intraarticular infusion of ropivacaine.

Providing intraarticular analgesia with a continuous infusion of local anesthetic via a disposable infusion pump has gained popularity. Despite the prevalence of this technique, data comparing this method of analgesia to conventional regional anesthesia are not available. We present a prospective study that compared a single-dose interscalene block with a single-dose interscalene block plus continuous intraarticular infusion of local anesthetic. Forty patients scheduled for shoulder arthroscopy were entered in this prospective, double-blinded study. All patients received an interscalene brachial plexus block as their primary anesthetic. Patients were randomly assigned to 1 of 2 groups: 1. interscalene block with 1.5% mepivacaine (40 mL) followed by a postoperative intraarticular infusion of 0.5% ropivacaine at 2 mL/h, or 2. interscalene block with 0.5% ropivacaine (40 mL) followed by a postoperative intraarticular infusion of 0.9% saline (placebo) at 2 mL/h. Postoperative infusions were maintained for 48 h. Visual analog scale pain scores and postoperative oxycodone consumption were measured for 48 h. Visual analog scale scores at rest and with ambulation in the Mepivacaine/Intraarticular Ropivacaine group were reduced when compared with the Ropivacaine/Saline group (rest: P = 0.003, ambulation: P = 0.006). Oxycodone consumption was also decreased (28 +/- 21 mg vs 44 +/- 28 mg, P = 0.046), respectively. We conclude that a brachial plexus block with 1.5% mepivacaine and a continuous intraarticular infusion of 0.5% ropivacaine at 2 mL/h provides improved analgesia for minor surgery at 24 and 48 h versus a single-injection interscalene block with 0.5% ropivacaine.

Ambulatory surgery for multi-ligament knee reconstruction with continuous dual catheter peripheral nerve blockade.

PURPOSE: Major reconstructive surgery of the knee traditionally requires an extended hospital stay for pain management. Continuous peripheral nerve blockade is an alternative method of pain control but is seldom used in the ambulatory setting. This case illustrates the use of lumbar plexus and sciatic nerve peripheral catheters for major knee surgery using intermittent bolus dosing for outpatient analgesia. CLINICAL FEATURES: A 20-yr-old male presented for multi-ligamentous knee reconstruction (posterior collateral ligament and revision anterior collateral ligament and lateral collateral ligament). Anesthesia was managed with a lumbar plexus and a sciatic nerve peripheral catheter and a light general anesthetic. Post-operative analgesia was provided with a 12-hr infusion of 0.2% ropivacaine in an over night recovery care centre. Subsequent catheter dosing was performed as an outpatient, twice a day using 0.2% ropivacaine, 10 ml in each catheter (four injections total). This provided 96 hr of analgesia and low supplemental opioid use. CONCLUSION: The use of a lumbar plexus and sciatic nerve peripheral catheter offered an alternative to conventional pain control that worked well in the ambulatory setting. By providing prolonged unilateral lower limb analgesia, extensive knee surgery was performed that would normally require a hospital stay for pain control. Using a bolus dosing method the risk of local anesthetic complications occurring outside of the hospital with a continuous infusion was minimized.

Continuous peripheral nerve block for ambulatory surgery.

BACKGROUND AND OBJECTIVES: Continuous peripheral nerve block (CPNB) can provide surgical anesthesia, prolonged postoperative analgesia, and acceptable side effects. Despite these advantages, CPNB is not in widespread use. Recently a new CPNB catheter system (Contiplex, B. Braun, Bethlehem, PA) was developed based on an insulated Tuohy needle, which allows for injection of local anesthetic and catheter insertion without disconnection or needle movement. At present, no clinical studies exist describing this system. METHODS: Data were prospectively gathered for 1 year from 228 patients in an ambulatory surgery center. All CPNB were performed using the Contiplex system to provide anesthesia and postoperative analgesia. CPNB were performed using 5 upper and lower extremity techniques. Postsurgery local anesthetic was infused and at 24 hours, a rebolus of local anesthetic was performed. The CPNB catheter was removed and patients were examined for loss of sensation. Patients were then discharged. RESULTS: Initial peripheral block was successful in 94% of patients. Failed nerve block requiring general anesthesia occurred in 6%. The catheter was patent and functional in 90% of patients at 24 hours, and 8% of patients required more than 10 mg of intravenous morphine by 24 hours postsurgery. In the postanesthesia care unit (PACU), only 4 patients (1.7%) required treatment for nausea. At 24 hours and 7 days postsurgery, no patient reported a dysesthesia. CONCLUSIONS: CPNB using the insulated Tuohy catheter system offered acceptable anesthesia and prolonged pain relief postsurgery. There were few side effects. Reg Anesth Pain Med 2001;26:209-214.

Patient satisfaction and effectiveness of lumbar plexus and sciatic nerve block for total knee arthroplasty.

The purpose of this study was to evaluate the efficacy of combined lumbar plexus block techniques for total knee arthroplasty. Long-acting local anesthetics were used to ensure adequate intraoperative and postoperative anesthesia and analgesia. All patients undergoing total knee arthroplasty at our institution were offered lumbar plexus block after obtaining informed consent. Patients for study were a continuous group of 87 patients over a 1-year period. A subset of 40 patients was studied for postoperative analgesia effect. All patients were contacted by phone for a satisfaction survey. There were 87 patients who received initial lumbar plexus and sciatic nerve blocks, 78% (68 of 87) of whom had adequate initial blocks. Sixteen patients (22%) required conversion to general anesthesia intraoperatively because of inadequate anesthesia. A subset of patients studied for postoperative analgesia revealed an average time of 13 hours before the first request for supplemental narcotics. There were no complications related to the lumbar plexus block in our study group of patients. There was a 92% overall satisfaction rate with the anesthesia provided by the lumbar plexus block. Lumbar plexus block can be used successfully for total knee arthroplasty. Lumbar plexus block appears to have advantages for early postoperative analgesia, leading to increased patient comfort and satisfaction.

Update on ropivacaine.

Long-acting local anaesthetics are primarily used in the practice of anaesthesia, particularly in regional anaesthesia and analgesia. Ropivacaine is a new long-acting local anaesthetic that has been the focus of interest because of its increased cardiovascular safety compared with bupivacaine. Other advantages of ropivacaine over bupivacaine include a greater sensorimotor differential block and shorter elimination half-life (t(1/2)), with a lower potential for accumulation. The most important attribute of ropivacaine, however, is its increased margin of safety compared with bupivacaine when given in equal doses. Many post-marketing studies have focused on the comparisons of efficacy in blocks and toxicity profiles of bupivacaine versus ropivacaine. Recent animal toxicity studies confirm the results of original studies showing that ropivacaine has less cardiovascular toxicity than bupivacaine with respect to direct myocardial depression, success of resuscitation and arrhythmogenic potential when given in equal doses. Reduced cardiotoxicity may be a distinct characteristic of ropivacaine. A review of current literature suggests that, at clinically relevant doses, ropivacaine provides the lowest potential risk of cardiotoxicity for inadvertent intravascular injection. Studies are currently under way comparing ropivacaine with levobupivacaine, the latest addition to the group of long-acting local anaesthetics.

Interscalene brachial plexus block with a continuous catheter insertion system and a disposable infusion pump.

Continuous interscalene brachial plexus blockade traditionally requires a hospital stay for local anesthetic infusion, and achieving consistent catheter insertion may be difficult. Incorporating long-acting pain relief from a continuous peripheral nerve block, with a reliable method of catheter insertion, and a self-contained infusion system would be a valuable asset for short-stay care. We compared the efficacy of single injection interscalene brachial plexus blockade to a continuous peripheral nerve block, with an insulated Tuohy system and a disposable infusion pump. Forty adult patients scheduled for open rotator cuff repair were entered in this randomized, double-blinded, placebo-controlled study. Patients received an interscalene brachial plexus blockade and a continuous peripheral nerve catheter as their primary anesthetic and then, were assigned to receive one of two different postoperative infusions: either 0.2% ropivacaine at 10 mL/h via a disposable infusion pump or normal saline at 10 mL/h via a disposable infusion pump (n = 18-20 per group). Visual analog pain scores and postoperative morphine consumption were measured for 24 h. The ropivacaine group showed less pain than the placebo group (P: = 0.0001) between 12 and 24 h after the initial injection of local anesthetic. In addition, initial interscalene blockade was successful in all patients and all redosed catheters were functional after 24 h with the continuous catheter insertion system. We conclude that it is possible to achieve a high rate of successful catheter placement and analgesia by using the continuous catheter insertion system and a disposable infusion pump in the ambulatory setting. This method of analgesia may offer improved pain relief after outpatient rotator cuff repair.

Thromboelastography as a perioperative measure of anticoagulation resulting from low molecular weight heparin: a comparison with anti-Xa concentrations.

UNLABELLED: Low molecular weight heparin (LMWH) is commonly used to prevent postoperative thromboembolism. Currently, there is no convenient test to measure the degree of anticoagulation from LMWH. This prospective study examines the relationship of thromboelastography and serum anti-Xa concentration in patients treated with enoxaparin. Twenty-four adult patients scheduled for orthopedic surgery using epidural anesthesia were enrolled. Epidural catheters were removed the morning after surgery before the commencement of subcutaneous enoxaparin 30 mg twice daily. Venous blood samples were obtained at 1) the induction of anesthesia (baseline), 2) immediately before the third dose of enoxaparin postoperatively (Day 2-trough), 3) 4 h after the third dose postoperatively (Day 2-peak), and 4) immediately before the fifth dose postoperatively (Day 3-trough). Whole blood samples were obtained for thromboelastography, activated clotting time, and anti-Xa level analyses at each of the four time intervals. At the four sample intervals, the r time (mean +/- SEM). (20 +/- 1, 25 +/- 2, 51 +/- 6, 31 +/- 3 mm) and the k time (9 +/- 0. 7, 12 +/- 1, 27 +/- 5, 14 +/- 2 mm) of the thromboelastograph were significantly correlated with the expected peak and trough levels of LMWH and serum anti-Xa levels (P: < 0.05). At the Day 3-trough, thromboelastograph r times exceeded the normal range in 6 of 25 patients (25%). Prolongation of r time and k time on postoperative Day 3 may indicate an exaggerated response to LMWH. Thromboelastography is a test that could potentially correlate with the degree of anticoagulation produced by low molecular weight heparin. IMPLICATIONS: Thromboelastography is a test that could potentially correlate with the degree of anticoagulation produced by low molecular weight heparin. The r time from the thromboelastogram correlates with serum anti-Xa concentration.

Regional anesthesia for ambulatory surgery.

Ambulatory surgery is increasing at unprecedented rates with more complex procedures being performed. This article reviews the benefits of the use of regional anesthesia during ambulatory surgeries. Regional anesthesia, by putting the anesthetic at the surgical site, provides ideal conditions for ambulatory surgery and provides a smooth, predictable post-operative course.

Thoracic paravertebral block for breast surgery.

UNLABELLED: Cosmetic and reconstructive breast augmentation is a frequently performed surgical procedure. Despite advances in medical treatment, surgical intervention is often associated with postoperative pain, nausea, and vomiting. Paravertebral nerve block (PVB) has the potential to offer long-lasting pain relief and fewer postoperative side effects when used for breast surgery. We compared thoracic PVB with general anesthesia for cosmetic breast surgery in a single-blinded, prospective, randomized study of 60 women scheduled for unilateral or bilateral breast augmentation or reconstruction. Patients were assigned (n = 30 per group) to receive a standardized general anesthetic (GA) or thoracic PVB (levels T1-7). Procedural data were collected, as well as verbal and visual analog pain and nausea scores. Verbal postoperative pain scores were significantly lower in the PVB group at 30 min (P = 0.0005), 1 h (P = 0.0001), and 24 h (P = 0.04) when compared with GA. Nausea was less severe in the PVB group at 24 h (P = 0.04), but not at 30 min or 1 h. We conclude that PVB is an alternative technique for cosmetic breast surgery that may offer superior pain relief and decreased nausea to GA alone. IMPLICATIONS: Paravertebral nerve block has the potential to offer long-lasting pain relief and few postoperative side effects when used for breast surgery. We demonstrated that paravertebral nerve block, when compared with general anesthesia, is an alternative technique for breast surgery that may offer pain relief superior to general anesthesia alone.

Sameridine is safe and effective for spinal anesthesia: a comparative dose-ranging study with lidocaine for inguinal hernia repair.

UNLABELLED: Sameridine is a new compound with local anesthetic and analgesic properties when injected intrathecally. We studied the anesthetic and analgesic efficacy of three doses of isobaric sameridine (15, 20, and 23 mg) compared with 100 mg of hyperbaric lidocaine for spinal anesthesia in 140 healthy male patients undergoing inguinal hernia repair. Patients received spinal anesthesia with 4 mL of the study drug injected at the L2-3 or L3-4 interspace in the lateral decubitus position. All three doses of sameridine provided spinal anesthesia similar to lidocaine, with a slightly longer time to reach peak block height. The failure rate was highest in the 15-mg sameridine group, and accrual was discontinued in that group after 35 patients. The duration of blockade was shorter with lidocaine, but the time to voiding and ambulation was similar in all groups. Patients receiving sameridine were less likely to request morphine for postoperative analgesia and were less likely to request any analgesia in the first 4 h after injection of the drug. Use of oral analgesics (hydrocodone and acetaminophen) was similar in all groups after the first 4 h of the 24-h observation. We conclude that, in the three doses studied, sameridine provided spinal anesthesia similar to lidocaine, but with residual analgesia after drug injection that reduced the need for systemic analgesics in the first 4 h postoperatively. IMPLICATIONS: In this clinical trial, we show the potential efficacy of a class of drugs that can produce both spinal anesthesia and postoperative analgesia when used for hernia repair.

A comparison of 0.5% bupivacaine, 0.5% ropivacaine, and 0.75% ropivacaine for interscalene brachial plexus block.

UNLABELLED: The onset time and duration of action of ropivacaine during an interscalene block are not known. The potentially improved safety profile of ropivacaine may allow the use of higher concentrations to try and speed onset time. We compared bupivacaine and ropivacaine to determine the optimal long-acting local anesthetic and concentration for interscalene brachial plexus block. Seventy-five adult patients scheduled for outpatient shoulder surgery under interscalene block were entered into this double-blind, randomized study. Patients were assigned (n = 25 per group) to receive an interscalene block using 30 mL of 0.5% bupivacaine, 0.5% ropivacaine, or 0.75% ropivacaine. All solutions contained fresh epinephrine in a 1:400,000 concentration. At 1-min intervals after local anesthetic injection, patients were assessed to determine loss of shoulder abduction and loss of pinprick in the C5-6 dermatomes. Before discharge, patients were asked to document the time of first oral narcotic use, when incisional discomfort began, and when full sensation returned to the shoulder. The mean onset time of both motor and sensory blockade was <6 min in all groups. Duration of sensory blockade was similar in all groups as defined by the three recovery measures. We conclude that there is no clinically important difference in times to onset and recovery of interscalene block for bupivacaine 0.5%, ropivacaine 0.5%, and ropivacaine 0.75% when injected in equal volumes. IMPLICATIONS: In this study, we demonstrated a similar efficacy between equal concentrations of ropivacaine and bupivacaine. In addition, increasing the concentration of ropivacaine from 0.5% to 0.75% fails to improve the onset or duration of interscalene brachial plexus block.

Paravertebral somatic nerve block for outpatient inguinal herniorrhaphy: an expanded case report of 22 patients.

BACKGROUND AND OBJECTIVES: Inguinal herniorrhaphy is a common outpatient surgical procedure. However, anesthetic techniques for inguinal herniorrhaphy are still associated with numerous side effects. Paravertebral somatic nerve block (PSNB) has the potential advantage to offer unilateral abdominal wall anesthesia and long-lasting pain relief with minimal side effects. We report our initial trial of PSNB for outpatient inguinal herniorrhaphy. METHODS: Twenty-two patients received a PSNB at T10 to L2 using 5 mL of 0.5% bupivacaine with epinephrine 1:400,000 at each of the five levels. The onset of surgical anesthesia, duration of analgesia, side effects, and patient satisfaction with the technique were documented. RESULTS: Surgical anesthesia occurred 15-30 minutes after injection. Two patients had a failed block. The mean +/- SD time to onset of discomfort was 14 +/- 11 hours. Time until first narcotic requirement was 22 +/- 18 hours. Thirteen patients (n = 20) had no incisional discomfort 10 hours or longer after their blocks. Three patients had epidural spread. Most patients were very satisfied with their anesthetic technique. CONCLUSIONS: The results of our initial experience suggest that PSNB is a potentially safe and effective technique. In general, the block provided long-lasting pain relief in most patients with few side effects. A randomized study comparing paravertebral blocks with conventional anesthesia choices is suggested given the findings in this initial series of patients.

Use of paravertebral block anesthesia in the surgical management of breast cancer: experience in 156 cases.

OBJECTIVE: To assess safety and efficacy of the regional anesthetic technique paravertebral block for operative treatment of breast cancer, and to compare postoperative pain, nausea, vomiting, and length of hospital stay in patients undergoing breast surgery using paravertebral block and general anesthesia. BACKGROUND: General anesthesia is currently the standard technique used for surgical treatment of breast cancer. Increasing hospital costs have focused attention on reducing the length of hospital stay for these patients. However, the side effects and complications of general anesthesia preclude ambulatory surgery for most patients undergoing breast surgery. In April 1994, the authors initiated the use of paravertebral block anesthesia for patients undergoing primary breast cancer surgery. A review of our early experience revealed that this regional anesthetic technique enables effective anesthesia for operative procedures of the breast and axilla, reduces postoperative nausea and vomiting, and provides prolonged postoperative sensory block that minimizes narcotic requirements. METHODS: A retrospective analysis of 145 consecutive patients undergoing 156 breast cancer operations using paravertebral block and 100 patients undergoing general anesthesia during a 2-year period was performed. Anesthetic effectiveness and complications, inpatient experience with postoperative pain, nausea, vomiting, and length of stay were measured. RESULTS: Surgery was successfully completed in 85% of the cases attempted by using paravertebral block alone, and in 91% of the cases, surgery was completed by using paravertebral block supplemented with local anesthetic. There was a 2.6% incidence of complications associated with block placement. Twenty percent of patients in the paravertebral group required medication for nausea and vomiting during their hospital stay compared with 39% in the general anesthesia group. Narcotic analgesia was required in 98% of general anesthesia patients, as opposed to 25% of patients undergoing paravertebral block. Ninety-six percent of patients having paravertebral block anesthesia were discharged within the day of surgery, compared with 76% of patients who had a general anesthetic. CONCLUSIONS: Paravertebral block can be used to perform major operations for breast cancer with minimal complications and a low rate of conversion to general anesthesia. Paravertebral block markedly improves the quality of recovery after breast cancer surgery and provides the patient with the option of ambulatory discharge.