Peripheral nerve blocks in the management of postoperative pain: challenges and opportunities.

Peripheral nerve blocks (PNBs) are increasingly used as a component of multimodal analgesia and may be administered as a single injection (sPNB) or continuous infusion via a perineural catheter (cPNB). We undertook a qualitative review focusing on sPNB and cPNB with regard to benefits, risks, and opportunities for optimizing patient care. Meta-analyses of randomized controlled trials have shown superior pain control and reductions in opioid consumption in patients receiving PNB compared with those receiving intravenous opioids in a variety of upper and lower extremity surgical procedures. cPNB has also been associated with a reduction in time to discharge readiness compared with sPNB. Risks of PNB, regardless of technique or block location, include vascular puncture and bleeding, nerve damage, and local anesthetic systemic toxicity. Site-specific complications include quadriceps weakness in patients receiving femoral nerve block, and pleural puncture or neuraxial blockade in patients receiving interscalene block. The major limitation of sPNB is the short (12-24 hours) duration of action. cPNB may be complicated by catheter obstruction, migration, and leakage of local anesthetic as well as accidental removal of catheters. Potential infectious complications of catheters, although rare, include local inflammation and infection. Other considerations for ambulatory cPNB include appropriate patient selection, education, and need for 24/7 availability of a health care provider to address any complications. The ideal PNB technique would have a duration of action that is sufficiently long to address the most intense period of postsurgical pain; should be associated with minimal risk of infection, neurologic complications, bleeding, and local anesthetic systemic toxicity; and should be easy to perform, convenient for patients, and easy to manage in the postoperative period.

Ultrasound-Guided Out-of-Plane vs. In-Plane Interscalene Catheters: A Randomized, Prospective Study.

BACKGROUND: Continuous interscalene blocks provide excellent analgesia after shoulder surgery. Although the safety of the ultrasound-guided in-plane approach has been touted, technical and patient factors can limit this approach. We developed a caudad-to-cephalad out-of-plane approach and hypothesized that it would decrease pain ratings due to better catheter alignment with the brachial plexus compared to the in-plane technique in a randomized, controlled study. OBJECTIVES: To compare an out-of-plane interscalene catheter technique to the in-plane technique in a randomized clinical trial. PATIENTS AND METHODS: Eighty-four patients undergoing open shoulder surgery were randomized to either the in-plane or out-of-plane ultrasound-guided continuous interscalene technique. The primary outcome was VAS pain rating at 24 hours. Secondary outcomes included pain ratings in the recovery room and at 48 hours, morphine consumption, the incidence of catheter dislodgments, procedure time, and block difficulty. Procedural data and all pain ratings were collected by blinded observers. RESULTS: There were no differences in the primary outcome of median VAS pain rating at 24 hours between the out-of-plane and in-plane groups (1.50; IQR, [0 - 4.38] vs. 1.25; IQR, [0 - 3.75]; P = 0.57). There were also no differences, respectively, between out-of-plane and in-plane median PACU pain ratings (1.0; IQR, [0 - 3.5] vs. 0.25; IQR, [0 - 2.5]; P = 0.08) and median 48-hour pain ratings (1.25; IQR, [1.25 - 2.63] vs. 0.50; IQR, [0 - 1.88]; P = 0.30). There were no differences in any other secondary endpoint. CONCLUSIONS: Our out-of-plane technique did not provide superior analgesia to the in-plane technique. It did not increase the number of complications. Our technique is an acceptable alternative in situations where the in-plane technique is difficult to perform.

Setting up an acute pain management service.

Successful implementation of an acute pain management service involves a team approach in which team members have clearly defined roles. Clinical protocols are designed to help address common problems and prevent errors. As the complexity of surgery and patients' diseases continues to increase, current knowledge of new analgesic medications, acute pain literature, and skills in regional anesthesia techniques is imperative. Emphasizing a multimodal approach can improve analgesia and decrease opioid-related side effects.

Perioperative pain management for total knee arthroplasty.

Pain management following total knee arthroplasty (TKA) can be challenging. Inadequate pain management following TKA may inhibit rehabilitation, increase morbidity and mortality, decrease patient satisfaction, and lead to chronic persistent postsurgical pain. Traditionally the mainstay of postoperative pain management was opioids; however, the current recommendations to pain management emphasize a multimodal approach and minimizing opioids whenever possible. With careful planning and a multimodal analgesic approach instituted perioperatively, appropriate pain management following TKA can be achieved. Utilizing an extensive review of the literature, this article discusses the analgesic techniques available for the perioperative management of TKA.

Perioperative management of interscalene block in patients with lung disease.

Interscalene nerve block impairs ipsilateral lung function and is relatively contraindicated for patients with lung impairment. We present a case of an 89-year-old female smoker with prior left lung lower lobectomy and mild to moderate lung disease who presented for right shoulder arthroplasty and insisted on regional anesthesia. The patient received a multimodal perioperative regimen that consisted of a continuous interscalene block, acetaminophen, ketorolac, and opioids. Surgery proceeded uneventfully and postoperative analgesia was excellent. Pulmonary physiology and management of these patients will be discussed. A risk/benefit discussion should occur with patients having impaired lung function before performance of interscalene blocks. In this particular patient with mild to moderate disease, analgesia was well managed through a multimodal approach including a continuous interscalene block, and close monitoring of respiratory status took place throughout the perioperative period, leading to a successful outcome.

Spinal anesthesia: should everyone receive a urinary catheter?: a randomized, prospective study of patients undergoing total hip arthroplasty.

BACKGROUND: The objective of this randomized prospective study was to determine whether a urinary catheter is necessary for all patients undergoing total hip arthroplasty under spinal anesthesia. METHODS: Consecutive patients undergoing total hip arthroplasty under spinal anesthesia were randomized to treatment with or without insertion of an indwelling urinary catheter. All patients received spinal anesthesia with 15 to 30 mg of 0.5% bupivacaine. The catheter group was subjected to a standard postoperative protocol, with removal of the indwelling catheter within forty-eight hours postoperatively. The experimental group was monitored for urinary retention and, if necessary, had straight catheterization up to two times prior to the placement of an indwelling catheter. RESULTS: Two hundred patients were included in the study. There was no significant difference between the two groups in terms of the prevalence of urinary retention, the prevalence of urinary tract infection, or the length of stay. Nine patients in the no-catheter group and three patients in the catheter group (following removal of the catheter) required straight catheterization because of urinary retention. Three patients in the catheter group and no patient in the no-catheter group had development of urinary tract infection. CONCLUSIONS: Patients undergoing total hip arthroplasty under spinal anesthesia appear to be at low risk for urinary retention. Thus, a routine indwelling catheter is not required for such patients.

Fascia lliaca block for analgesia after hip arthroplasty: a randomized double-blind, placebo-controlled trial.

BACKGROUND AND OBJECTIVES: Fascia iliaca block (FIB) is often used to treat pain after total hip arthroplasty (THA), despite a lack of randomized trials to evaluate its efficacy for this indication. The objective of this study was to assess the analgesic benefit of FIB after THA. Our primary hypothesis was administration of FIB decreases the intensity of postoperative pain (numeric rating scale [NRS-11] score) compared with sham block (SB) in patients after THA. METHODS: After institutional review board approval and informed consent, 32 eligible patients having THA were recruited. In the postoperative care unit, although all patients received intravenous morphine sulfate patient-controlled analgesia, patients reporting pain of 3 or greater on the NRS-11 scale were randomized to receive ultrasound-guided fascia iliaca (30 mL 0.5% ropivacaine) or SB (30 mL 0.9% NaCl) using identical technique, below fascia iliaca. The primary outcome was pain intensity (NRS-11) after FIB. RESULTS: Thirty-two patients (16 in each group) completed the study; all patients received an FIB. There was no difference in pain intensity (NRS-11 = 5.0 ± 0.6 vs 4.7 ± 0.6, respectively) after FIB versus SB or in opioid consumption (8.97 ± 1.6 vs 5.7 ± 1.6 mg morphine, respectively) between the groups at 1 hour. The morphine consumption after 24 hours was similar in both groups (49.0 ± 29.9 vs 50.4 ± 34.5 mg, P = 0.88, respectively). CONCLUSIONS: The evidence in these data suggests that the difference in average pain intensity after FIB versus SB was not significant (95% confidence interval, -2.2-1.4 NRS units).

Acute pain management in the postanesthesia care unit.

Pain management in the postanesthesia care unit (PACU) is continually evolving, with several new nonopioids expanding the list of available agents. Pain in the PACU is not an inevitable outcome of surgery. With careful planning, multimodal analgesic techniques instituted preoperatively will reduce pain in the PACU. Accurate assessment of the characteristics of pain will direct rational drug choices while minimizing side effects. Better management of pain in the PACU setting will likely improve patient satisfaction and facilitate shorter PACU stays.

Preoperative anemia in total joint arthroplasty: is it associated with periprosthetic joint infection?

BACKGROUND: Anemia is common in patients undergoing total joint arthroplasty (TJA). Numerous studies have associated anemia with increased risk of infection, length of hospital stay, and mortality in surgical populations. However, it is unclear whether and to what degree preoperative anemia in patients undergoing TJA influences postoperative periprosthetic joint infection (PJI) and mortality. QUESTIONS/PURPOSES: We therefore (1) determined the incidence of preoperative anemia in patients undergoing TJA; (2) assessed the possible association between preoperative anemia and subsequent PJI; and (3) explored the relationship between preoperative anemia with postoperative mortality. METHODS: We identified 15,722 patients who underwent TJA from January 2000 to June 2007. Anemia was defined as hemoglobin < 12 g/dL in women and hemoglobin < 13 g/dL in men. We determined the effect of preoperative anemia, demographics, and comorbidities on postoperative complications. RESULTS: Of the 15,222 patients, 19.6% presented with preoperative anemia. PJI occurred more frequently in anemic patients at an incidence of 4.3% in anemic patients compared with 2% in nonanemic patients. Thirty-day (0.4%), 90-day (0.6%), and 1-year (1.8%) mortality rates were not higher in patients with preoperative anemia. Forty-four percent of anemic patients received an allogenic transfusion compared with only 13.4% of nonanemic patients. Anemic patients had increased hospital stays averaging 4.3 days compared with 3.9 days in nonanemic patients. Anemia did not predict cardiac complications. CONCLUSION: Our data demonstrate that preoperative anemia is associated with development of subsequent PJI. Preoperative anemia was not associated with 30-day, 60-day, or 1-year mortality in this cohort. LEVEL OF EVIDENCE: Level III, diagnostic study. See the Guidelines for Authors for a complete description of levels of evidence.

Quantifying cardiovascular risks in patients with metabolic syndrome undergoing total joint arthroplasty.

The coexistence of diabetes, hypertension, obesity, and dyslipidemia is defined as metabolic syndrome. Studies show substantial cardiovascular risks among these patients. The risk of patients with metabolic syndrome undergoing total joint arthroplasty (TJA) is unknown. Patients with and without metabolic syndrome undergoing TJA during a 3-year period were analyzed for postoperative complications. Metabolic syndrome was defined by having 3 of the following 4 criteria: obesity (body mass index ≥30 kg/m(2)), dyslipidemia, hypertension, and diabetes. Patients with metabolic syndrome had a significantly higher risk of cardiovascular complications compared with controls (P = .017). The risk of an adverse event increased by 29% and 32%, respectively, when there were 3 or 4 syndrome components. Patients with metabolic syndrome undergoing TJA have increased risk for cardiovascular complications. Our results show that metabolic syndrome may have a clustering effect and pose increased risk when individual risks factors are combined.

The effect of stimulating versus conventional perineural catheters on postoperative analgesia following ultrasound-guided femoral nerve localization.

STUDY OBJECTIVE: To test the hypothesis that, if the femoral nerve is correctly localized using ultrasound (US) guidance, the type of perineural catheter used has no effect on catheter success. DESIGN: Randomized controlled trial. SETTING: Post-anesthesia care unit of an academic teaching hospital. PATIENTS: 40 ASA physical status 1, 2, and 3 patients, ages 55-85 years, undergoing elective total knee arthroplasty. INTERVENTIONS: All patients received postoperative continuous femoral nerve blocks and a single injection sciatic nerve block. Nerve localization was accomplished using US guidance and electrical nerve stimulation so that the needle tip was visualized deep to the femoral nerve. Patients were randomized to receive either stimulating (Group SC) or nonstimulating catheters (Group NSC) in the usual manner for each device. Catheters were bolused with ropivacaine and an infusion commenced. MEASUREMENTS: The primary outcome was quality of analgesia (as measured by a numerical rating scale). Other outcomes included sensory block success rate, number of attempts and time required to localize the needle tip correctly, number of attempts and time required to place the perineural catheter, amount of local anesthetic and opioid use postoperatively, and degree of completion of preset postoperative rehabilitation goals. MAIN RESULTS: Quality of analgesia was similar at all time intervals. Rates of successful femoral block (95% vs 80%; P = 0.34) were similar between groups. Time required to position the catheter was greater in Group SC than Group NSC (3.45 ± 2.05 min vs 1.72 ± 0.88 min; P < 0.01). CONCLUSIONS: Ultrasound guidance for needle localization prior to catheter insertion for femoral nerve block results in similar block characteristics between stimulating and nonstimulating catheters. The use of nonstimulating catheters avoids the technical challenges of stimulating catheters and does not require additional helpers.

Multimodal pain management after total joint arthroplasty.

Adequate postoperative pain control in patients who have undergone total joint arthroplasty allows faster rehabilitation and reduces the rate of postoperative complications. Multimodal pain management involves the introduction of adjunctive pain control methods in an attempt to control pain with less reliance on opioids and fewer side effects. Current research suggests that traditional nonsteroidal anti-inflammatory drugs (NSAIDs) and the associated cyclooxygenase type-2 (COX-2) inhibitors improve pain control in most cases. Nearly all multimodal pain management modalities have a safe side-effect profile when they are added to existing methods. The exception is the administration of DepoDur (extended-release epidural morphine) to elderly or respiratory-compromised patients because of a potential for hypoxia and cardiopulmonary events.

Challenges in acute pain management.

The management of acute pain remains challenging, with many patients suffering inadequate pain control following surgery. Certain populations are at unique risk for unrelieved pain. Evidence-based approaches taking into account patients' specific needs and problems will likely substantially improve their perioperative experience. These patients must be identified in the preoperative process, and an anesthetic/analgesic plan discussed and formulated. A targeted multimodal approach to pain management should be considered the best clinical practice. The most challenging patients may benefit most from the surveillance of an acute pain service that is able to monitor and coordinate care into the postoperative period.

The effect of mixing 1.5% mepivacaine and 0.5% bupivacaine on duration of analgesia and latency of block onset in ultrasound-guided interscalene block.

BACKGROUND: Short- and long-acting local anesthetics are commonly mixed to achieve nerve blocks with short onset and long duration. However, there is a paucity of data on advantages of such mixtures. We hypothesized that a mixture of mepivacaine and bupivacaine results in a faster onset than does bupivacaine and in a longer duration of blockade than does mepivacaine. METHODS: Sixty-four patients undergoing arthroscopic shoulder surgery (ages 18 to 65 years; ASA physical status I-II) with ultrasound-guided interscalene brachial plexus block as the sole anesthetic were studied. The subjects were randomized to receive 1 of 3 study solutions: 30 mL of mepivacaine 1.5%, 30 mL of bupivacaine 0.5%, or a mixture of 15 mL each of bupivacaine 0.5% and mepivacaine 1.5%. The block onset time and duration of motor and sensory block were assessed. RESULTS: Onset of sensory block in the axillary nerve distribution (superior trunk) was similar among the 3 groups (8.7 ± 4.3 minutes for mepivacaine, 10.0 ± 5.1 minutes for bupivacaine, and 11.3 ± 5.3 minutes for the combination group; P = 0.21 between all groups). The duration of motor block for the combination group (11.5 ± 4.7 hours) was between that of the bupivacaine (16.4 ± 9.4 hours) and mepivacaine (6.0 ± 4.2 hours) groups (P = 0.03 between bupivacaine and combination groups; P = 0.01 between mepivacaine and combination groups). Duration of analgesia was the shortest with mepivacaine (4.9 ± 2.4 hours), longest with bupivacaine (14.0 ± 6.2 hours), and intermediate with the combination group (10.3 ± 4.9 hours) (P < 0.001 for mepivacaine vs. combination group; P = 0.01 for bupivacaine vs. combination group). CONCLUSIONS: For ultrasound-guided interscalene block, a combination of mepivacaine 1.5% and bupivacaine 0.5% results in a block onset similar to either local anesthetic alone. The mean duration of blockade with a mepivacaine-bupivacaine mixture was significantly longer than block with mepivacaine 1.5% alone but significantly shorter than the block with bupivacaine 0.5% alone.

Postoperative pain management techniques in hip and knee arthroplasty.

Adequate control of postoperative pain following hip and knee arthroplasty can be a challenging task fraught with potential complications. Postoperative pain is perceived by the patient via a complex network and a multitude of molecular messengers in both the peripheral and central nervous systems. This allows the physician to modulate pain via an array of medications that act on different sites within the body. Using both contemporary and traditional pain modulators, the delivery and timing of these medications can affect postoperative pain and, ultimately, rehabilitation of the arthroplasty patient. Current techniques for controlling pain use both multimodal and preemptive analgesia to improve the outcome of the surgery while minimizing the potential adverse effects of the medications given.

Operative vaginal delivery and neonatal and infant adverse outcomes: population based retrospective analysis.

OBJECTIVE: To compare the risk of neonatal and infant adverse outcomes between vacuum and forceps assisted deliveries. DESIGN: Population based study. SETTING: US linked natality and mortality birth cohort file and the New Jersey linked natality, mortality, and hospital discharge summary birth cohort file. PARTICIPANTS: Singleton live births in the United States (n = 11 639 388) and New Jersey (n = 375 351). MAIN OUTCOME MEASURES: Neonatal morbidity and mortality. RESULTS: Neonatal mortality was comparable between vacuum and forceps deliveries in US births (odds ratio 0.94, 95% confidence interval 0.79 to 1.12). Vacuum delivery was associated with a lower risk of birth injuries (0.69, 0.66 to 0.72), neonatal seizures (0.78, 0.68 to 0.90), and need for assisted ventilation (< 30 minutes 0.94, 0.92 to 0.97; > or = 30 minutes 0.92, 0.88 to 0.98). Among births in New Jersey, vacuum extraction was more likely than forceps to be complicated by postpartum haemorrhage (1.22, 1.07 to 1.39) and shoulder dystocia (2.00, 1.62 to 2.48). The risks of intracranial haemorrhage, difficulty with feeding, and retinal haemorrhage were comparable between both modes of delivery. The sequential use of vacuum and forceps was associated with an increased risk of need for mechanical ventilation in the infant and third and fourth degree perineal tears. CONCLUSION: Although vacuum extraction does have risks, it remains a safe alternative to forceps delivery.