Perioperative Cefazolin for Total Joint Arthroplasty Patients Who Have a Penicillin Allergy: Is It Safe?

BACKGROUND: Cefazolin is the standard of care for perioperative antibiotic prophylaxis in total joint arthroplasty (TJA) in the United States. The potential allergic cross-reactivity between cefazolin and penicillin causes uncertainty regarding optimal antibiotic choice in patients who have a reported penicillin allergy (rPCNA). The purpose of this study was to determine the safety of perioperative cefazolin in PCNA patients undergoing primary TJA. METHODS: We identified all patients (n = 49,842) undergoing primary total hip arthroplasty (n = 25,659) or total knee arthroplasty (n = 24,183) from 2016 to 2022 who received perioperative intravenous antibiotic prophylaxis. Patients who had an rPCNA (n = 5,508) who received cefazolin (n = 4,938, 89.7%) were compared to rPCNA patients who did not (n = 570, 10.3%), and to patients who did not have an rPCNA (n = 43,359). The primary outcome was the rate of allergic reactions within 72 hours postoperatively. Secondary outcomes included the rates of superficial infections, deep infections, and Clostridioides difficile infections within 90 days. RESULTS: The rate of allergic reactions was 0.1% (n = 5) in rPCNA patients who received cefazolin, compared to 0.2% (n = 1) in rPCNA patients who did not (P = .48) and 0.02% (n = 11) in patients who have no rPCNA (P = .02). Allergic reactions were mild in all 5 rPCNA patients who received cefazolin and were characterized by cutaneous symptoms (n = 4) or dyspnea in the absence of respiratory distress (n = 1) that resolved promptly with antibiotic discontinuation and administration of antihistamines and/or corticosteroids. We observed no differences in the rates of superficial infections (0.1 versus 0.2%, P = .58), deep infections (0.3 versus 0.4%, P = .68), or C difficile infections (0.04% versus 0%, P = .99) within 90 days in rPCNA patients who received cefazolin versus alternative perioperative antibiotics. CONCLUSIONS: In this series of more than 5,500 patients who had an rPCNA undergoing primary TJA, perioperative prophylaxis with cefazolin resulted in a 0.1% incidence of allergic reactions that were clinically indolent. Cefazolin can be safely administered to most patients, independent of rPCNA severity. LEVEL OF EVIDENCE: III.

Effectiveness of oral versus intravenous tranexamic acid in primary total hip and knee arthroplasty: a randomised, non-inferiority trial.

BACKGROUND: Tranexamic acid (TXA) reduces rates of blood transfusion for total hip arthroplasty (THA) and total knee arthroplasty (TKA). Although the use of oral TXA rather than intravenous (i.v.) TXA might improve safety and reduce cost, it is not clear whether oral administration is as effective. METHODS: This noninferiority trial randomly assigned consecutive patients undergoing primary THA or TKA under neuraxial anaesthesia to either one preoperative dose of oral TXA or one preoperative dose of i.v. TXA. The primary outcome was calculated blood loss on postoperative day 1. Secondary outcomes were transfusions and complications within 30 days of surgery. RESULTS: Four hundred participants were randomised (200 THA and 200 TKA). The final analysis included 196 THA patients (98 oral, 98 i.v.) and 191 TKA patients (93 oral, 98 i.v.). Oral TXA was non-inferior to i.v. TXA in terms of calculated blood loss for both THA (effect size=-18.2 ml; 95% confidence interval [CI], -113 to 76.3; P<0.001) and TKA (effect size=-79.7 ml; 95% CI, -178.9 to 19.6; P<0.001). One patient in the i.v. TXA group received a postoperative transfusion. Complication rates were similar between the two groups (5/191 [2.6%] oral vs 5/196 [2.6%] i.v.; P=1.00). CONCLUSIONS: Oral TXA can be administered in the preoperative setting before THA or TKA and performs similarly to i.v. TXA with respect to blood loss and transfusion rates. Switching from i.v. to oral TXA in this setting has the potential to improve patient safety and decrease costs.

Minimizing Opioid Use After Total Hip Arthroplasty: Comparing Periarticular Injection Versus Patient-Controlled Epidural Analgesia Versus a Combination Protocol.

BACKGROUND: Effective management of postoperative pain after total hip arthroplasty (THA) may be challenging. We sought to develop an opioid-sparing pain management pathway by comparing the relative effectiveness of 3 different protocols: (1) Local anesthetic administered patient-controlled epidural analgesia (PCEA) without intrathecal opioids; (2) Periarticular injection (PAI); and (3) PCEA + PAI. METHODS: In this double-blinded randomized controlled trial, 180 patients undergoing THA were randomized to receive either (1) PCEA with 0.06% bupivacaine, (2) PAI, or (3) a PAI + PCEA with 0.06% bupivacaine. All patients received the same postoperative multimodal analgesic regimen. The primary outcome was opioid consumption, measured in oral morphine equivalents, at 24, 48, and 72 hours after anesthesia stop time. Secondary measures included pain at rest and with movement, opioid side effects, patient satisfaction, and quality of recovery, as assessed via standardized self-reporting scales and surveys. RESULTS: Opioid consumption was significantly higher in the PAI group in the first 24 hours postoperatively compared to the PAI + PCEA group (30 versus 15, P = .012). No differences were detected among groups for length of stay, pain scores, patient satisfaction, or duration of surgery. More patients in the PAI + PCEA group were opiate-free in the first 24 hours compared to PAI (23.7 versus 8.5%, P = .043). CONCLUSION: Use of PAI + PCEA regimen was opioid-sparing in the first 24 hours after surgery, favoring this group when opioid reduction is desired. Increased drowsiness was noted in the subsequent 24 to 48 hours once the epidural catheter was removed and opioid consumption also increased.

Association between same day discharge total knee and total hip arthroplasty and risks of cardiac/pulmonary complications and readmission: a population-based observational study.

OBJECTIVE: To determine if same-day discharge total knee arthroplasty (TKA) or total hip arthroplasty (THA) is not associated with increased risk of unplanned readmission and adverse outcomes within 30 days of surgery. DESIGN: This is a population-based observational study. SETTING: Patients from 708 participating institutions who underwent primary TKA or primary THA between 2011 and 2017 were divided into three groups by length of stay (LOS 0, 1 and 2-3 days). All patients with LOS>3 days were excluded from the current study. Regression analysis and propensity score matching were performed. DATA SOURCES: American College of Surgeons-National Surgical Quality Improvement Programme database. MAIN OUTCOMES AND MEASURES: Primary outcomes included unplanned readmission and cardiac/pulmonary complications within 30 days of surgery. RESULTS: We identified 226 481 TKA (LOS 0=3118, LOS 1=31 404, and LOS 2-3=1 91 959) and 140 557 THA patients (LOS 0=2652, LOS 1=29 617, and LOS 2-3=1 08 288). There were no differences in 30-day mortality. After adjusting for relevant covariates, LOS 0 (compared with LOS 1) was associated with higher odds of cardiac/pulmonary complications in both TKA (OR 1.95, 95% CI 1.20 to 3.16; 0.67% vs 0.37%) and THA (OR 1.96, 95% CI 1.05 to 3.64; 0.57% vs 0.26%). There were no statistical differences in unplanned readmissions between LOS 0 and LOS 1 groups in TKA (2.41% vs 2.31%) and THA (1.62% vs 2.04%). CONCLUSIONS: LOS 0 discharge after TKA and THA was associated with higher odds of cardiac/pulmonary complications compared with LOS 1 discharge. While the overall burden of complications is relatively low, until future studies can confirm or challenge our findings, a measured approach is advisable when recommending discharge of patients on the same day of surgery.

A comparison of two different concentrations and infusion rates of ropivacaine in perineural infusion administered at the same total dose for analgesia after foot and ankle surgery: a randomized, double blinded, controlled study.

BACKGROUND: Continuous popliteal nerve block is utilized for postoperative analgesia after foot and ankle surgery. Whether only the total dose of local anesthetic or the combination of concentration and volume determine the characteristics of a continuous popliteal nerve infusion remains currently unknown. We hypothesized a reduction of the incidence of insensate extremity in patients given ropivacaine 0.4% at 4 mL/h compared to patients given ropivacaine 0.2% at 8 mL/h. METHODS: Sixty-four patients scheduled for major foot and ankle surgery requiring a continuous popliteal catheter infusion for postoperative analgesia were studied. Thirty-three patients were randomized to receive a continuous popliteal nerve block with 0.2% (basal 8 mL/h) and thirty-one with 0.4% (basal 4 mL/h) ropivacaine, reaching the same total dose (16 mg/h). The primary outcome was the incidence of persistent sensory block in the distal sciatic nerve distributions in the postoperative period. Secondary outcomes were the incidence of motor block, NRS pain scores at rest in the postoperative period up to 48 hours after surgery, opioid use and related side effects, patients' satisfaction. RESULTS: The incidence of persistent sensory block was similar in patients given 0.2% and in patients receiving 0.4% ropivacaine. The incidence of motor block, postoperative pain scores at rest, use of oral opioids, side effects and patients' satisfaction with the quality of recovery were also similar in both groups. CONCLUSIONS: Our results suggest that local anesthetic total dose is the primary determinant of continuous popliteal perineural infusion effects.

Addition of Infiltration Between the Popliteal Artery and the Capsule of the Posterior Knee and Adductor Canal Block to Periarticular Injection Enhances Postoperative Pain Control in Total Knee Arthroplasty: A Randomized Controlled Trial.

BACKGROUND: Periarticular injections (PAIs) are becoming a staple component of multimodal joint pathways. Motor-sparing peripheral nerve blocks, such as the infiltration between the popliteal artery and capsule of the posterior knee (IPACK) and the adductor canal block (ACB), may augment PAI in multimodal analgesic pathways for knee arthroplasty, but supporting literature remains rare. We hypothesized that the addition of ACB and IPACK to PAI would lower pain on ambulation on postoperative day (POD) 1 compared to PAI alone. METHODS: This triple-blinded randomized controlled trial included 86 patients undergoing unilateral total knee arthroplasty. Patients either received (1) a PAI (control group, n = 43) or (2) an IPACK with an ACB and modified PAI (intervention group, n = 43). The primary outcome was pain on ambulation on POD 1. Secondary outcomes included numeric rating scale (NRS) pain scores, patient satisfaction, and opioid consumption. RESULTS: The intervention group reported significantly lower NRS pain scores on ambulation than the control group on POD 1 (difference in means [95% confidence interval], -3.3 [-4.0 to -2.7]; P < .001). In addition, NRS pain scores on ambulation on POD 0 (-3.5 [-4.3 to -2.7]; P < .001) and POD 2 (-1.0 [-1.9 to -0.1]; P = .033) were significantly lower. Patients in the intervention group were more satisfied, had less opioid consumption (P = .005, postanesthesia care unit, P = .028, POD 0), less intravenous opioids (P < .001), and reduced need for intravenous patient-controlled analgesia (P = .037). CONCLUSIONS: The addition of IPACK and ACB to PAI significantly improves analgesia and reduces opioid consumption after total knee arthroplasty compared to PAI alone. This study strongly supports IPACK and ACB use within a multimodal analgesic pathway.

Thirty-Day Acute Health Care Resource Utilization Following Outpatient Anterior Cruciate Ligament Surgery.

BACKGROUND AND OBJECTIVES: The need for hospital-based acute care following outpatient surgical procedures is expensive and measured as marker for quality. However, little information is available about events leading to emergency department visit or inpatient admission after ambulatory anterior cruciate ligament (ACL) surgery. METHODS: We studied adult patients who underwent outpatient ACL surgery in New York State between 2009 and 2013 using the Healthcare Cost and Utilization Project database. Emergency department visits and inpatient admissions within 30 days of surgery were identified by cross-matching 2 additional independent Healthcare Cost and Utilization Project databases. RESULTS: The final cohort included 26,873 subjects. We identified 1208 (3.90%; 95% confidence interval [CI], 3.6%-4.1%) secondary health care encounters of interest. The majority of these encounters were emergency department visits (951). The most common reasons were musculoskeletal pain (349 [28.9%]), any infection (122 [10.1%]), drug abuse (98 [8.1%]), wound infection (87 [7.2%]), deep venous thrombosis (77 [6.4%]), and psychotic events (54 [4.5%]). Patients operated on in high-volume surgical centers were less likely to require acute care (odds ratio, 0.47; P < 0.001; 95% CI, 0.34-0.63), whereas Medicare/Medicaid patients carried higher odds (odds ratio, 2.52; 99% CI, 2.07-3.07). CONCLUSIONS: The rate of hospital-based acute care following outpatient ACL surgery was 3.90%. Many of the events were expected complications related to surgery, such as infection and deep venous thrombosis. However, musculoskeletal pain, drug abuse, and psychotic events featured more prominently than expected. Our findings may direct efforts to address these reasons for seeking acute care after ACL surgery, reduce cost, and improve quality of care.

Perineural dexamethasone with subsartorial saphenous nerve blocks in ACL reconstruction.

PURPOSE: Subsartorial saphenous nerve blockade (SSNB) is an effective analgesic alternative to femoral nerve blockade after anterior cruciate ligament (ACL) reconstruction with bone-tendon-bone (BTB) autograft. It was hypothesized that dexamethasone in a SSNB will prolong analgesia, improve pain and satisfaction, and reduce postoperative opioid requirements and side effects. METHODS: One hundred ninety-five patients undergoing ACL reconstruction with BTB autograft (ages 16-65) were enrolled. Subjects received SSNB with 13 ml of 0.5 % bupivacaine (control group), 1 mg preservative-free dexamethasone +0.5 % bupivacaine (treatment group I), or 4 mg preservative-free dexamethasone +0.5 % bupivacaine (treatment group II). Subjects received identical perioperative management. On postoperative days 1 and 2, subjects reported perceived block duration, pain scores, satisfaction, opioid use, and side effects. Cox-proportional hazards modelling was used to compare block duration, adjusting for body mass index, age, sex, tourniquet time, American Society of Anesthesiologists classification, and intravenous dexamethasone dose. RESULTS: Patient-perceived block duration was significantly increased in treatment group I [hazard ratio (95 % confidence interval [CI]) 0.48 (0.31-0.75); P = 0.001] and treatment group II (hazard ratio (95 % CI): 0.52 (0.33-0.81); P = 0.004) compared to control. The block was extended from a median (95 % CI) of 33.1 (28.4-37.3) to 41.2 (32.4-50.9) and 46.5 (35.8-48.9) hours, respectively. Additionally, patients in treatment group II reported increased time that block provided pain relief, higher patient satisfaction, lower pain scores at rest, and decreased drowsiness and confusion. CONCLUSION: The addition of 1 and 4 mg of dexamethasone to the block injectate significantly increased SSNB duration by 8-13 h compared to control. LEVEL OF EVIDENCE: Therapeutic study, level 1.

Prospective, Randomized Double-Blind Study: Does Decreasing Interscalene Nerve Block Volume for Surgical Anesthesia in Ambulatory Shoulder Surgery Offer Same-Day Patient Recovery Advantages?

BACKGROUND AND OBJECTIVES: In this randomized double-blind prospective study in patients undergoing shoulder arthroscopy, we compared the effects of ultrasound-guided interscalene nerve block using 20 mL (intervention group) and 40 mL (control group) of a mepivacaine 1.5% and bupivacaine 0.5% mixture (1:1 volume) on ipsilateral handgrip strength and other postoperative end points. METHODS: One hundred fifty-four patients scheduled for ambulatory shoulder arthroscopy were randomly assigned to receive a single-injection interscalene block under ultrasound guidance with either 40 mL (control) or 20 mL (intervention) and intravenous sedation. The primary outcome was the change in ipsilateral handgrip strength in the postanesthesia care unit (PACU) measured with a dynamometer. Secondary end points were recorded, including negative inspiratory force, incidences of hoarseness and Horner syndrome, time to readiness for discharge from PACU, time to discharge from PACU, patient satisfaction, time to block resolution, and pain scores. RESULTS: Postoperative handgrip strength was greater in the 20-mL group compared with the 40-mL group (difference in means, 2.3 kg [95% confidence interval, 0.6-4.0 kg]; P = 0.009). A smaller proportion of patients in the intervention group experienced hoarseness postoperatively compared with the control group (odds ratio, 0.26 [95% confidence interval, 0.08-0.82]; P = 0.015). Patient satisfaction and duration of analgesia were similar in both groups. CONCLUSIONS: When used for surgical anesthesia for shoulder arthroscopies in the ambulatory setting, a 20-mL volume in an ultrasound-guided interscalene block preserves greater handgrip strength on the ipsilateral side in the PACU compared with 40 mL without significant decrease in block success, duration of analgesia, and patient satisfaction.

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

BACKGROUND: Adequate 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/PURPOSES: This 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. METHODS: A 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. RESULTS: No 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. CONCLUSION: These 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.

Adductor canal block versus femoral nerve block for total knee arthroplasty: a prospective, randomized, controlled trial.

BACKGROUND: This prospective double-blinded, randomized controlled trial compared adductor canal block (ACB) with femoral nerve block (FNB) in patients undergoing total knee arthroplasty. The authors hypothesized that ACB, compared with FNB, would exhibit less quadriceps weakness and demonstrate noninferior pain score and opioid consumption at 6 to 8 h postanesthesia. METHODS: Patients received an ACB or FNB as a component of a multimodal analgesic. Quadriceps strength, pain score, and opioid consumption were assessed on both legs preoperatively and at 6 to 8, 24, and 48 h postanesthesia administration. In a joint hypothesis test, noninferiority was first evaluated on the primary outcomes of strength, pain score, and opioid consumption at 6 to 8 h; superiority on each outcome at 6 to 8 h was then assessed only if noninferiority was established. RESULTS: Forty-six patients received ACB; 47 patients received FNB. At 6 to 8 h postanesthesia, ACB patients had significantly higher median dynamometer readings versus FNB patients (median [interquartile range], 6.1 kgf [3.5, 10.9] (ACB) vs. 0 kgf [0.0, 3.9] (FNB); P < 0.0001), but was not inferior to FNB with regard to Numeric Rating Scale pain scores (1.0 [0.0, 3.5] ACB vs. 0.0 [0.0, 1.0] FNB; P = 0.019), or to opioid consumption (32.2 [22.4, 47.5] ACB vs. 26.6 [19.6, 49.0]; P = 0.0115). At 24 and 48 h postanesthesia, there was no significant statistical difference in dynamometer results, pain scores, or opioid use between the two groups. CONCLUSION: At 6 to 8 h postanesthesia, the ACB, compared with the FNB, exhibited early relative sparing of quadriceps strength and was not inferior in both providing analgesia or opioid intake.

Association of obesity with inflammation and pain after total hip arthroplasty.

BACKGROUND: The prevalence of obesity is increasing, and obesity often leads to degenerative joint disease requiring total hip arthroplasty (THA). Obesity is a proinflammatory state associated with an increase in chronic, low-grade inflammatory response. As such, it may augment the postoperative inflammatory response, which has been associated with postoperative pain and complications. QUESTIONS/PURPOSES: We determined whether severity of obesity was associated with (1) severity of inflammatory response, as measured by the in vivo circulating levels of cytokines and ex vivo functional reactivity of mononuclear blood cells, and (2) severity of pain, as measured by verbal pain scores and analgesic consumption, in the first 24 hours after THA. METHODS: We studied 60 patients (20 normal weight, 20 overweight, 20 obese) undergoing elective primary unilateral THA in this prospective cross-sectional study. Blood samples were collected for C-reactive protein and cytokine levels, including IL-1ß, IL-2, IL-6, IL-8, and tumor necrosis factor α (TNF-α), from patients before and 24 hours after surgery. Cytokine response of whole blood was evaluated ex vivo with or without two standard activators, phorbol-12-myristate-13-acetate and lipopolysaccharide, using standardized blood sample from patients at 24 hours. These standard immune activators are implicated in the inflammatory response to gram-negative infection, translocation of microbial products, pathophysiology of septic shock syndrome in human, and tumor promotion. Pain response was gauged using verbal pain scores (on a 0- to 10-point scale, where 0 = no pain and 10 = worst pain) at rest and with activity at 24 hours after surgery and analgesic consumption of volume of epidural analgesic solution for the first 24 hours after surgery. RESULTS: No correlation was found between BMI and postoperative spontaneous circulating cytokine levels. However, after activation of blood leukocytes with lipopolysaccharide, there was a significant positive correlation between the BMI and IL-1ß, IL-6, and TNF-α levels (r = 0.26-0.32; p = 0.03, p = 0.03, and p = 0.01, respectively), suggesting priming of the innate immune system in obesity and potential for excessive postoperative inflammatory response. Obesity was not associated with increased pain or analgesic consumption in the first 24 hours after surgery. CONCLUSIONS: Obesity is associated with a proinflammatory state after THA as demonstrated by enhanced cytokine reactivity. Larger studies exploring the specific impact of obesity and inflammation on surgical outcomes, including pain, are warranted. LEVEL OF EVIDENCE: Level II, therapeutic study. See the Instructions for Authors for a complete description of levels of evidence.

Nerve stimulator versus ultrasound guidance for placement of popliteal catheters for foot and ankle surgery.

STUDY OBJECTIVE: To determine whether ultrasound guidance improves the quality of continuous popliteal block when compared with a nerve stimulator after major foot and ankle surgery. DESIGN: Prospective, randomized, double-blinded clinical trial. SETTING: Operating room, Postanesthesia Care Unit (PACU), and hospital wards of a university-affiliated hospital. PATIENTS: 45 ASA physical status 1, 2, and 3 patients undergoing elective major foot and ankle surgery. INTERVENTIONS: Placement of a popliteal sciactic nerve catheter using either nerve stimulator or ultrasound guidance. In the PACU, a continuous infusion of ropivacaine 0.2% was started at a basal rate of 4 mL/hr and adjusted in a standardized fashion to maintain visual analog scale (VAS) pain scores < 4. All patients also received intravenous (IV) patient-controlled analgesia with hydromorphone and oral opioids. MEASUREMENTS: VAS pain scores at rest and with physical therapy, ropivacaine use, opioid use, and opioid-related side effects were recorded. MAIN RESULTS: Cummulative ropivacaine use was lower in patients whose catheter was placed by ultrasound than by nerve stimulator guidance (mean 50 vs 197 mL, P < 0.001). Pain scores at rest and during activity were similar between groups. Cumulative opioid consumption (mean 858 vs 809 mg oral morphine equivalents) and daily frequencies of nausea (5% to 33% vs 0 to 24%) and pruritus (0 to 21% vs 0 to 24%) were similar between groups. Length of hospital stay was similar between groups (3.5 vs 3.7 days). CONCLUSIONS: Ultrasound guidance was associated with less local anesthetic consumption than with the nerve stimulator; however, there was little clinical benefit, as all other outcomes were similar between groups.

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.

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.

Correlation between centrally versus peripherally transduced venous pressure in prone patients undergoing posterior spine surgery.

STUDY DESIGN: Prospective clinical observational study. OBJECTIVE: To evaluate the correlation and agreement between peripherally and centrally transduced venous pressures in prone spine surgery patients. SUMMARY OF BACKGROUND DATA: In view of a variety of potential complications associated with the placement of central venous lines for the purpose of central venous pressure (CVP) monitoring, a number of authors have suggested that the use of peripherally transduced pressures (PVP) instead may yield similar results. Data confirming the validity of this technique for the purpose of intravascular fluid volume monitoring in prone patients undergoing spine surgery remain scarce. METHODS: After protocol approval by the internal review board, we enrolled 40 patients who underwent spine surgery in the prone position. CVP and PVP were recorded simultaneously. The data pairs were analyzed for correlation. Bland and Altman plots were created to evaluate the degree of agreement between the 2 modes of venous pressure monitoring. RESULTS: A total of 1275 data pairs were collected. The mean PVP was 17.55 mm Hg +/- 4.93 mm Hg and the mean CVP 15.52 mm Hg +/- 4.77 mm Hg (P < 0.001), thus yielding a mean difference of 2.04 mm Hg +/- 1.39 mm Hg. PVP and CVP correlated well over a wide range of pressures (r = 0.949, r = 0.920 [P < 0.001]). A high level of agreement was found between both methods of venous pressure measurement. CONCLUSION: CVP and PVP correlate well under conditions associated with prone spine surgery. With a high level of agreement found in this study, PVP may represent an attractive alternative to CVP monitoring to assess fluid volume trends intraoperatively.