Kishor Gandhi

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.

Preoperative Anemia in Total Joint Arthroplasty: Is It Associated with Periprosthetic Joint Infection?

BackgroundAnemia 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/PurposesWe 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.MethodsWe 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.ResultsOf 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.ConclusionOur 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 EvidenceLevel III, diagnostic study. See the Guidelines for Authors for a complete description of levels of evidence.

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.

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.

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.

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).

Volume and dose of local anesthetic necessary to block the axillary brachial plexus using ultrasound guidance.

IN this issue of ANESTHESIOLOGY, O’Donnell and Iohom report a successful block of the brachial plexus at the axilla with as little as 1 ml of 2% lidocaine per nerve. Their findings are at odds with the conventional experience in which axillary brachial plexus block has been typically associated with a variable success rate ranging from 50% to 100%, even when substantially larger volumes of local anesthetics are used. Before the introduction of electrolocalization and/or ultrasound guidance, blind injection of the local anesthetic around the axillary artery (transarterial technique) was the predominant method used to block the axillary brachial plexus. Failures or incomplete blocks were thought to be caused by imprecise needle placement or septation of the brachial plexus sheath, leading to malposition of the local anesthetic. In 1961, De Jong showed that success of the axillary perivascular technique depends on the injection of a sufficient volume of local anesthetic and recommended that 42 ml of local anesthetic was necessary to fill the axillary brachial plexus sheath. To increase the success rate, larger volumes of local anesthetic, as much as 80 ml in some reports, have been used, with techniques using multiple injections. Only few investigators reported the ability of small aliquots of local anesthetic (e.g., 5 ml/nerve) to result in successful block. So, can ultrasound guidance increase the efficacy and decrease the 15% volumes of local anesthetic necessary to accomplish a successful block? According to Casati et al., there is no significant difference in block success rate or speed of onset between ultrasound and multistimulation techniques when 20 ml of 0.75% ropivacaine are used. Lo and colleagues concluded that the volume used to block the axillary brachial plexus was smaller by a mere (7 ml) with ultrasound as compared to transarterial or nerve stimulation techniques (40 ml vs. 47 ml). In the study by Chan and colleagues, ultrasound guidance improved the success rate of axillary brachial plexus block, but it still resulted in a 17% failure rate using 42 ml of 2% lidocaine and 0.5% bupivacaine. These recent studies were all contributed by leading groups in the application of ultrasound for regional anesthesia, and yet, even with substantially greater volumes and doses of local anesthetic, none reported as fast and reliable blockade as the current report. So, how does one explain the spectacular results of O’Donnell and Iohom with as little as 1 ml/nerve of 2% lidocaine? One possibility is that their results are related to an über-precise deposition of local anesthetic by an anesthesiologist and ultrasonographer extraordinaire. Perhaps these were intraneural injections of local anesthetics for which only miniscule amounts of injectate are necessary to accomplish blockade? Or, are their results overly optimistic due to a type-I error because of the small sample size in their up and down design? The research of yesteryear was largely concerned with identifying volumes of local anesthetic and techniques to “fill” the axillary brachial plexus sheath to “capacity.” Could it be, as O’Donnell and Iohom imply, that a less conventional, opposite direction – enhancing the precision and determining the lowest amount of local anesthetic necessary for blockade – is the future? Our inability to provide a definitive answer to these questions stems from the unpredictability of the placement and disposition of local anesthetic. It is this factor that has traditionally hampered our efforts to define the relationship among dose, volume, and concentration of the local anesthetic to reliability, quality, and duration of the blockade. The effects of these variables with application of local anesthetics have largely been studied in laboratories on isolated nerves by measuring compound action potentials or on single nerve fibers using voltage clamp techniques. Many of these studies bare little relevance to clinical practice because multilayered ensheathments of peripheral nerves in patients impede the diffusion of drugs into the ion channels. Furthermore, there is a significant variability in the nerve/connective tissue ratio, not only among the nerves, but also at different locations along the same nerve. Such anatomic variability may help explain why a higher concentration of local anesthetic is required to block the sciatic nerve in the popliteal fossa than at the subgluteal fold. When applied directly to ion channels, the concentration of local anesthetics necessary to cause conduction block is small compared to those used clinically. Therefore, it would seem ideal if the means used to localize nerves allowed for precise administration of local anesthetics on the inner side of connective tissues without risking mechanical or injection injury to the axons. If so, should intraneural but extrafascicular injections, at least for large peripheral nerves (i.e., sciatic nerve), become a preferable method of performing blocks in the future? (Personal verbal communication, Xavier Sala-Blanch, M.D., This Editorial View accompanies the following article: O’Donnell B, Iohom G: An estimation of the minimum effective anesthetic volume of 2% lidocaine in ultrasound-guided axillary brachial plexus block. ANESTHESIOLOGY 2009; 111:25–9.

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.

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.