Daniel B. Maalouf

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.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. 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. 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. 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.

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.

Association of Obesity With Inflammation and Pain After Total Hip Arthroplasty

BackgroundThe 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/purposesWe 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.MethodsWe 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-1β, 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.ResultsNo 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-1β, 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.ConclusionsObesity 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 EvidenceLevel II, therapeutic study. See the Instructions for Authors for a complete description of levels of evidence.

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

BackgroundAdequate 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/PurposesThis 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.MethodsA 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.ResultsNo 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.ConclusionThese 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.

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.

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, r2 = 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.

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.

Adductor Canal Block versus Femoral Nerve Block for Total Knee ArthroplastyA 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.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. 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. 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. 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.

Adductor Canal Block : A Prospective, Randomized, Controlled Trial versus : A Prospective, Randomized, Controlled Trial 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.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. 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. 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. 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.