Nabil M. Elkassabany

Comparative Effectiveness of Regional versus General Anesthesia for Hip Fracture Surgery in Adults

Background: Hip fracture is a common, morbid, and costly event among older adults. Data are inconclusive as to whether epidural or spinal (regional) anesthesia improves outcomes after hip fracture surgery. Methods: The authors examined a retrospective cohort of patients undergoing surgery for hip fracture in 126 hospitals in New York in 2007 and 2008. They tested the association of a record indicating receipt of regional versus general anesthesia with a primary outcome of inpatient mortality and with secondary outcomes of pulmonary and cardiovascular complications using hospital fixed-effects logistic regressions. Subgroup analyses tested the association of anesthesia type and outcomes according to fracture anatomy. Results: Of 18,158 patients, 5,254 (29%) received regional anesthesia. In-hospital mortality occurred in 435 (2.4%). Unadjusted rates of mortality and cardiovascular complications did not differ by anesthesia type. Patients receiving regional anesthesia experienced fewer pulmonary complications (359 [6.8%] vs. 1,040 [8.1%], P < 0.005). Regional anesthesia was associated with a lower adjusted odds of mortality (odds ratio: 0.710, 95% CI 0.541, 0.932, P = 0.014) and pulmonary complications (odds ratio: 0.752, 95% CI 0.637, 0.887, P < 0.0001) relative to general anesthesia. In subgroup analyses, regional anesthesia was associated with improved survival and fewer pulmonary complications among patients with intertrochanteric fractures but not among patients with femoral neck fractures. Conclusions: Regional anesthesia is associated with a lower odds of inpatient mortality and pulmonary complications among all hip fracture patients compared with general anesthesia; this finding may be driven by a trend toward improved outcomes with regional anesthesia among patients with intertrochanteric fractures.

Does the routine prophylactic use of antiemetics affect the incidence of postdischarge nausea and vomiting following ambulatory surgery?: A systematic review of randomized controlled trials.

THE rapid increase in ambulatory surgery procedures performed over the past 10 yr has resulted in greater focus directed toward the control of postoperative nausea and vomiting (PONV), sometimes appropriately termed the “big, little problem.” The incidence of this complication is variable, but PONV has emerged as one of the commonest complications following ambulatory surgery, and the one that patients would most like to avoid. Specifically, the postdischarge period has been poorly studied but is important from the patient’s perspective. Despite the increasing availability of newer and more expensive drugs for the prevention of PONV, some authors question the routine use of single-drug prophylaxis in low-risk patients. The long-term ( 6 h) effect of antiemetics is even more uncertain in the ambulatory setting, because the focus of attention has previously been on the management of early PONV (in the day surgical unit). As many as 35–50% patients continue to have postdischarge nausea and vomiting (PDNV). It is important to control this symptom after discharge, because resumption of normal activities may be delayed if PONV is prolonged and ambulatory surgical patients are not under direct medical supervision after discharge. In our experience, few centers routinely provide antiemetics for the control of PDNV at home. Numerous systematic reviews have now been published in the literature on PONV, but only one has focused on PONV after hospital discharge in ambulatory surgical patients. This systematic review was completed to address the question of whether the routine prophylactic use of antiemetics affects the incidence of PDNV following ambulatory surgery. We restricted our analysis to randomized, controlled studies published in the English literature.

Neuraxial anesthesia decreases postoperative systemic infection risk compared with general anesthesia in knee arthroplasty.

BACKGROUND:Surgical stress has been shown to result in immune disturbance. Neuraxial anesthesia (NA) has long been hypothesized to blunt undesired surgical insults and thus limit immune compromise and improve surgical outcomes. We hypothesized that NA would decrease postoperative infectious complications compared with general anesthesia (GA) among knee arthroplasty patients. METHODS:We studied the American College of Surgeons National Surgical Quality Improvement Program database from 2005 to 2010. There were 16,555 patients included in our final cohort, with 9167 patients receiving GA and 7388 patients receiving spinal or epidural anesthesia.. Outcomes of interest included infection-related 30-day postoperative complications, including surgical site–related infections, pneumonia, urinary tract infection, sepsis, septic shock, and a composite end point of any systemic infection. Multivariable logistic regression was performed to test for effect of anesthesia type while adjusting for the influence of preexisting comorbidities. RESULTS:The overall mortality was 0.24% and 0.15% among NA and GA subjects, respectively (P = 0.214). NA subjects had fewer unadjusted incidences of pneumonia (P = 0.035) and composite systemic infection (P = 0.006). After risk adjustment for preexisting comorbidities, NA was associated with lower odds of pneumonia (odds ratio = 0.51 [95% confidence interval, 0.29–0.90]) and lower odds of composite systemic infection (odds ratio = 0.77 [95% confidence interval, 0.64–0.92]). CONCLUSIONS:Our study suggested that NA was associated with lower adjusted odds of both pneumonia and a composite outcome of any systemic infectious complication within 30 days of surgery compared with GA.

Comparison between the analgesic efficacy of transversus abdominis plane (TAP) block and placebo in open retropubic radical prostatectomy: a prospective, randomized, double-blinded study

STUDY OBJECTIVE To compare the efficacy of ultrasound-guided tansversus abdominis plane (TAP) block with placebo for postoperative analgesia after retropubic radical prostatectomy (RRP). DESIGN Prospective, randomized, double-blinded study. SETTING Tertiary-care Veterans Affairs (VA) hospital. PATIENTS ASA physical status 1, 2, and 3 patients scheduled for RRP. INTERVENTIONS Patients were randomized to two groups: the TAP group and the control group. All patients underwent an ultrasound-guided TAP block procedure after induction of general anesthesia and received either local anesthetic (TAP group) or normal saline (control group). MEASUREMENTS Opioid use and verbal analog pain scores at 1, 6, 12, and 24 hours after surgery were recorded, as was the frequency of side effects. Times to ambulation and first oral intake also were recorded. MAIN RESULTS The TAP block group had lower pain scores and required less total opioid in the first 24 hours after surgery. Time to first oral intake and time to ambulation were similar between the two groups. CONCLUSION The TAP block has early benefits in postoperative analgesia after RRP.

Is there a dose response of dexamethasone as adjuvant for supraclavicular brachial plexus nerve block? A prospective randomized double-blinded clinical study

STUDY OBJECTIVE The study objective is to examine the analgesic effect of 3 doses of dexamethasone in combination with low concentration local anesthetics to determine the lowest effective dose of dexamethasone for use as an adjuvant in supraclavicular brachial plexus nerve block. DESIGN The design is a prospective randomized double-blinded clinical study. SETTING The setting is an academic medical center. PATIENTS The patients are 89 adult patients scheduled for shoulder arthroscopy. INTERVENTIONS All patients were randomly assigned into 1 of 4 treatment groups: (i) bupivacaine, 0.25% 30 mL; (ii) bupivacaine, 0.25% 30 mL with 1-mg preservative-free dexamethasone; (iii) bupivacaine, 0.25% 30 mL with 2-mg preservative-free dexamethasone; and (iv) bupivacaine, 0.25% 30 mL with 4-mg preservative-free dexamethasone. All patients received ultrasound-guided supraclavicular brachial plexus nerve blocks and general anesthesia. MEASUREMENTS The measurements are the duration of analgesia and motor block. MAIN RESULTS The median analgesia duration of supraclavicular brachial plexus nerve block with 0.25% bupivacaine was 12.1 hours; and 1-, 2-, or 4-mg dexamethasone significantly prolonged the analgesia duration to 22.3, 23.3, and 21.2 hours, respectively (P = .0105). Dexamethasone also significantly extended the duration of motor nerve block in a similar trend (P = .0247). CONCLUSION Low-dose dexamethasone (1-2 mg) prolongs analgesia duration and motor blockade to the similar extent as 4-mg dexamethasone when added to 0.25% bupivacaine for supraclavicular brachial plexus nerve block.

The Risk of Falls After Total Knee Arthroplasty with the Use of a Femoral Nerve Block Versus an Adductor Canal Block: A Double-blinded Randomized Controlled Study

BACKGROUND:Adductor canal block (ACB) has emerged as an appealing alternative to femoral nerve block (FNB) that produces a predominantly sensory nerve block by anesthetizing the saphenous nerve. Studies have shown greater quadriceps strength preservation with ACB compared with FNB, but no advantage has yet been shown in terms of fall risk. The Tinetti scale is used by physical therapists to assess gait and balance, and total score can estimate a patient’s fall risk. We designed this study to test the primary hypothesis that FNB results in a greater proportion of “high fall risk” patients postoperatively using the Tinetti score compared with ACB. METHODS:After institutional review board approval, informed written consent to participate in the study was obtained. Patients undergoing primary unilateral total knee arthroplasty were eligible for enrollment in this double-blind, randomized trial. Patients received either an ACB or FNB (20 mL of 0.5% ropivacaine) with catheter placement (8 mL/h of 0.2% ropivacaine) in the setting of multimodal analgesia. Continuous infusion was stopped in the morning of postoperative day (POD)1 before starting physical therapy (PT). On POD1, PT assessed the primary outcome using the Tinetti score for gait and balance. Patients were considered to be at high risk of falling if they scored <19. Secondary outcomes included manual muscle testing of the quadriceps muscle strength, Timed Up and Go (TUG) test, and ambulation distance on POD1 and POD2. The quality of postoperative analgesia and the quality of recovery were assessed with American Pain Society Patient Outcome Questionnaire Revised and Quality of Recovery-9 questionnaire, respectively. RESULTS:Sixty-two patients were enrolled in the study (31 ACB and 31 FNB). No difference was found in the proportion of “high fall risk” patients on POD1 (21/31 in the ACB group versus 24/31 in the FNB group [P = 0.7]; relative risk, 1.14 [95% confidence interval, 0.84–1.56]) or POD2 (7/31 in the ACB versus 14/31 in the FNB group [P = 0.06]; relative risk, 2.0 [95% confidence interval, 0.94–4.27]). The average distance of ambulation during PT and time to up and go were similar on POD1 and POD2. Manual muscle testing grades were significantly higher on POD1 in the ACB group when compared with that in the FNB (P = 0.001) (Wilcoxon-Mann-Whitney odds, 2.25 [95% confidence interval, 1.35–4.26]). There were no other differences in postoperative outcomes. CONCLUSIONS:ACB results in greater preservation of quadriceps muscle strength. Although we did not detect a significant reduction in fall risk when compared with FNB, based on the upper limit of the relative risk, it may very well be present. Further study is needed with a larger sample size.

Anesthetic Management of Patients Undergoing Pulmonary Vein Isolation for Treatment of Atrial Fibrillation Using High-Frequency Jet Ventilation

OBJECTIVES The aim of this study was to describe anesthetic management and perioperative complications in patients undergoing pulmonary vein isolation for the treatment of atrial fibrillation under general anesthesia using high-frequency jet ventilation. The authors also identified variables associated with longer ablation times in this patient cohort. DESIGN A retrospective observational study. SETTING The electrophysiology laboratory in a major university hospital. PARTICIPANTS One hundred eighty-eight consecutive patients undergoing pulmonary vein isolation under general anesthesia with high-frequency jet ventilation. INTERVENTIONS High-frequency jet ventilation was used as the primary mode of ventilation under general anesthesia. MEASUREMENTS AND MAIN RESULTS High-frequency jet ventilation was performed successfully throughout the ablation procedure in 175 cases of the study cohort. The remaining 13 patients had to be converted to conventional positive-pressure ventilation because of high PaCO(2) or low PaO(2) on arterial blood gas measurements. Variables associated with a shorter ablation time included a higher ejection fraction (p = 0.04) and case volume performed by each electrophysiologist in the study group (p = 0.001). CONCLUSIONS High-frequency jet ventilation is generally a safe technique that can be used in catheter ablation treatment under general anesthesia.

Hypoalbuminemia More Than Morbid Obesity is an Independent Predictor of Complications After Total Hip Arthroplasty

Health care reform is directing clinical practice towards improving outcomes and minimizing complications. Preoperative identification of high-risk patients and modifiable risk factors present opportunity for clinical research. A total of 49,475 total hip arthroplasty patients were identified from National Surgical Quality Improvement Program between 2006 and 2013. We compared morbidly obese patients (BMI≥40 kg/m(2)) and non-morbidly obese patients (BMI 18.5-40 kg/m(2)). We also compared patients with hypoalbuminemia (serum albumin <3.5 g/dL) against those with normal albumin. Our study demonstrates that hypoalbuminemia is a significant risk factor for mortality and major morbidity among total hip arthroplasty patients, while morbid obesity was only associated with an increased risk of superficial surgical site infection. Impressively, hypoalbuminemia patients carried a 5.94-fold risk of 30-day mortality.

Dexamethasone as Adjuvant to Bupivacaine Prolongs the Duration of Thermal Antinociception and Prevents Bupivacaine-Induced Rebound Hyperalgesia via Regional Mechanism in a Mouse Sciatic Nerve Block Model

Background Dexamethasone has been studied as an effective adjuvant to prolong the analgesia duration of local anesthetics in peripheral nerve block. However, the route of action for dexamethasone and its potential neurotoxicity are still unclear. Methods A mouse sciatic nerve block model was used. The sciatic nerve was injected with 60ul of combinations of various medications, including dexamethasone and/or bupivacaine. Neurobehavioral changes were observed for 2 days prior to injection, and then continuously for up to 7 days after injection. In addition, the sciatic nerves were harvested at either 2 days or 7 days after injection. Toluidine blue dyeing and immunohistochemistry test were performed to study the short-term and long-term histopathological changes of the sciatic nerves. There were six study groups: normal saline control, bupivacaine (10mg/kg) only, dexamethasone (0.5mg/kg) only, bupivacaine (10mg/kg) combined with low-dose (0.14mg/kg) dexamethasone, bupivacaine (10mg/kg) combined with high-dose (0.5mg/kg) dexamethasone, and bupivacaine (10mg/kg) combined with intramuscular dexamethasone (0.5mg/kg). Results High-dose perineural dexamethasone, but not systemic dexamethasone, combined with bupivacaine prolonged the duration of both sensory and motor block of mouse sciatic nerve. There was no significant difference on the onset time of the sciatic nerve block. There was “rebound hyperalgesia” to thermal stimulus after the resolution of plain bupivacaine sciatic nerve block. Interestingly, both low and high dose perineural dexamethasone prevented bupivacaine-induced hyperalgesia. There was an early phase of axon degeneration and Schwann cell response as represented by S-100 expression as well as the percentage of demyelinated axon and nucleus in the plain bupivacaine group compared with the bupivacaine plus dexamethasone groups on post-injection day 2, which resolved on post-injection day 7. Furthermore, we demonstrated that perineural dexamethasone, but not systemic dexamethasone, could prevent axon degeneration and demyelination. There was no significant caspase-dependent apoptosis process in the mouse sciatic nerve among all study groups during our study period. Conclusions Perineural, not systemic, dexamethasone added to a clinical concentration of bupivacaine may not only prolong the duration of sensory and motor blockade of sciatic nerve, but also prevent the bupivacaine-induced reversible neurotoxicity and short-term “rebound hyperalgesia” after the resolution of nerve block.

The use of high-frequency jet ventilation for out of operating room anesthesia.

Purpose of review High-frequency jet ventilation is a novel technique for providing mechanical ventilation in the out of operating room (OOR) setting. Case reports and a small series of patients have shown it to be useful in patients undergoing cardiac arrhythmia ablations, interventional radiology procedures, and extracorporeal shock wave lithotripsy. Recently, interest in the technique has grown tremendously as the ability to provide superior surgical conditions may lead to improved efficiency and less side-effects in a variety of procedures. Recent findings Atrial fibrillation ablation procedures, liver tumor ablations, and extracorporeal shock wave lithotripsy are all the procedures that benefit from minimal movement of the heart, liver, and kidney, respectively, during the procedure. Although randomized controlled trials are lacking, increasing data suggest that by maintaining the thoracic and abdominal structures relatively immobile throughout the respiratory cycle, the efficiency and safety of these procedures may be improved. Summary Technological advances are allowing an increasing number of surgical procedures to be performed in the OOR setting. Such procedures often depend on the precise application of ablation catheters or shock waves. High-frequency jet ventilation facilitates the improved accuracy of catheter and shock wave placement, as well as efficiency of a variety of procedures. Improved efficiency, with fewer side-effects, has tremendous implications for the growth of such procedures in the OOR setting.