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.

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.

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.

Lumbar plexus and sciatic nerve block for knee arthroplasty: comparison of ropivacaine and bupivacaine.

PURPOSE: Information about the onset time and duration of action of ropivacaine during a combined lumbar plexus and sciatic nerve block is not available. This study compares bupivacaine and ropivacaine to determine the optimal long-acting local anaesthetic for lumbar plexus and sciatic nerve block in patients undergoing total knee arthroplasty. METHODS: Forty adult patients scheduled for unilateral total knee arthroplasty, under lumbar plexus and sciatic block were entered into this double-blind randomized study. Patients were assigned (20 per group) to receive lumbar plexus block using 30 ml of local anaesthetic and a sciatic nerve block using 15 ml of local anaesthetic with either bupivacaine 0.5% or ropivacaine 0.5%. All solutions contained fresh epinephrine in a 1:400,000 concentration. Every one minute after local anaesthetic injection, patients were assessed to determine loss of motor function and loss of pinprick sensation in the L1-S1 dermatomes. The time to request first analgesic was documented from the PCA pump. This time was used as evidence of block regression. RESULTS: Blocks failed in four patients in each group. The mean onset time of both motor and sensory blockade was between 14 and 18 min in both groups. Duration of sensory blockade was longer in the bupivacaine group, 17 +/- 3 hr, than in the ropivacaine group, 13 +/- 2 hr (P < 0.0001). CONCLUSION: We conclude that bupivacaine 0.5% and ropivacaine 0.5% have a similar onset of motor and sensory blockade when used for lumbar plexus and sciatic nerve block. Analgesic duration from bupivacaine 0.5% was prolonged by four hours compared with an equal volume of ropivacaine 0.5%.

Ambulatory surgical management of breast carcinoma using paravertebral block.

OBJECTIVE: The authors describe an initial experience using paravertebral block for ambulatory or short-stay operations for breast cancer. BACKGROUND: Rising hospital costs have focused attention on limiting the length of stay for patients undergoing surgical treatment of breast cancer. Thus far, ambulatory surgery has been limited by side effects and complications of general anesthesia. Paravertebral block offers the potential benefit of effective analgesia, with limited postoperative nausea and vomiting. METHODS: The medical records of the first 15 patients with breast cancer who underwent 16 major operations for the treatment of breast cancer using paravertebral block were reviewed. Patients were either discharged directly from the recovery room or after overnight hospital admission. The effectiveness of anesthesia, surgical outcome, patient satisfaction, and hospital costs are reviewed. RESULTS: Paravertebral block achieved effective anesthesia for cancer operations of the breast and axilla; conversion to general anesthesia or supplementation with local anesthesia was not required. There was one postoperative hemorrhage, there were two seromas, and there was one superficial wound infection. Sensory block persisted for an average of 23 hours. Postoperative pain was effectively controlled, in fact, nine patients required no postoperative narcotic for pain control. Nausea and vomiting transiently afflicted three patients and prompted overnight observation in one patient originally scheduled for immediate discharge. Fourteen patients (93%) rated their experience as "very satisfactory." CONCLUSION: Breast operations for the surgical management of breast cancer using paravertebral block can be performed safely, with great patient satisfaction, and with potential for significant cost savings.