Chronic Subdural Hematoma Drainage Under Local Anesthesia with Sedation versus General Anesthesia and Its Outcome.

BACKGROUND: Burr hole drainage is the criterion standard treatment for chronic subdural hematoma (CSDH), a common neurosurgical condition. However, apart from the surgical technique, the method of anesthesia also has a significant impact on postoperative patient outcome. Currently, there are limited studies comparing the use of local anesthesia with sedation (LA sedation) versus general anesthesia (GA) in the drainage of CSDH. The objective of this study was to compare the morbidity and mortality outcomes of using LA sedation versus GA in CSDH burr hole drainage. METHODS: This retrospective study presents a total of 257 operations in 243 patients from 2 hospitals. A total of 130 cases were operated under LA sedation in hospital 1 and 127 cases under GA in hospital 2. Patient demographics and presenting features were similar at baseline. RESULTS: Values are shown as LA sedation versus GA. Postoperatively, most patients recovered well in both groups with Glasgow Outcome Scale scores of 4-5 (96.2% vs. 88.2%, respectively). The postoperative morbidity was significantly increased by an odds ratio of 5.44 in the GA group compared with the LA sedation group (P = 0.005). The mortality was also significantly higher in the GA group (n = 5, 3.9%) than the LA sedation group (n = 0, 0.0%; P = 0.028). The CSDH recurrence rate was 4.6% in the LA sedation group versus 6.3% in the GA group. No intraoperative conversion from LA sedation to GA was reported. CONCLUSIONS: This study demonstrates that CSDH drainage under LA sedation is safe and efficacious, with a significantly lower risk of postoperative mortality and morbidity when compared with GA.

Comparison of regional and local anesthesia for arteriovenous fistula creation in end-stage renal disease: a systematic review and meta-analysis.

BACKGROUND: Arteriovenous fistulae (AVF) are the hemodialysis access modality of choice for patients with end-stage renal disease. However, they have a high early failure rate. Good vascular access is essential to manage long-term hemodialytic treatment, but some anesthesia techniques directly affect venous diameter as well as intra- and post-operative blood flow. The main purpose of this meta-analysis was to compare the results of regional and local anesthesia (RA and LA) for arteriovenous fistula creation in end-stage renal disease. METHODS: We conducted a systematic review and meta-analysis to synthesize evidence from 7 randomized controlled trials (565 patients) and 1 observational study (408 patients) with the aim of evaluating the safety and efficacy of RA versus LA in surgical construction of AVF. RESULTS: Pooled data showed that RA was associated with higher primary patency rates than LA (odds ratio [OR], 1.88; 95% confidence interval [CI]: 1.24-2.84; P = 0.003; I2 = 31%). Additionally, brachial artery diameter was significantly increased in the RA versus LA group (mean difference [MD], 0.83; 95% CI: 0.75-0.92; P < 0.001; I2 = 97%) and the need for intra- as well as post-operative pain killers was significantly less (RA, P = 0.0363; LA, P = 0.0318). Moreover, operation duration was significantly reduced using RA versus LA (MD, - 29.63; 95% CI: - 32.78 - -26.48; P < 0.001; I2 = 100%). CONCLUSIONS: This meta-analysis suggests that RA is preferable to LA in patients with end-stage renal disease in guaranteeing AVF patency and increasing brachial artery diameter.

Association Between Race and Ethnicity in the Delivery of Regional Anesthesia for Pediatric Patients: A Single-Center Study of 3189 Regional Anesthetics in 25,664 Surgeries.

BACKGROUND: Racial and ethnic disparities in health care are well documented in the United States, although evidence of disparities in pediatric anesthesia is limited. We sought to determine whether there is an association between race and ethnicity and the use of intraoperative regional anesthesia at a single academic children's hospital. METHODS: We performed a retrospective review of all anesthetics at an academic tertiary children's hospital between May 4, 2014, and May 31, 2018. The primary outcome was delivery of regional anesthesia, defined as a neuraxial or peripheral nerve block. The association between patient race and ethnicity (white non-Hispanic or minority) and receipt of regional anesthesia was assessed using multivariable logistic regression. Sensitivity analyses were performed comparing white non-Hispanic to an expansion of the single minority group to individual racial and ethnic groups and on patients undergoing surgeries most likely to receive regional anesthesia (orthopedic and urology patients). RESULTS: Of 33,713 patient cases eligible for inclusion, 25,664 met criteria for analysis. Three-thousand one-hundred eighty-nine patients (12.4%) received regional anesthesia. One thousand eighty-six of 8884 (13.3%) white non-Hispanic patients and 2003 of 16,780 (11.9%) minority patients received regional anesthesia. After multivariable adjustment for confounding, race and ethnicity were not found to be significantly associated with receiving intraoperative regional anesthesia (adjusted odds ratios [ORs] = 0.95; 95% confidence interval [CI], 0.86-1.06; P = .36). Sensitivity analyses did not find significant differences between the white non-Hispanic group and individual races and ethnicities, nor did they find significant differences when analyzing only orthopedic and urology patients, despite observing some meaningful clinical differences. CONCLUSIONS: In an analysis of patients undergoing surgical anesthesia at a single academic children's hospital, race and ethnicity were not significantly associated with the adjusted ORs of receiving intraoperative regional anesthesia. This finding contrasts with much of the existing health care disparities literature and warrants further study with additional datasets to understand the mechanisms involved.

A 10% blood pressure drop from baseline during mechanical thrombectomy for stroke is strongly associated with worse neurological outcomes.

BACKGROUND: Mechanical thrombectomy (MT) for acute ischemic stroke can be performed under local anesthesia, with or without conscious sedation (CS), or under general anesthesia (GA). The hemodynamic consequence of anesthetic drugs may explain why GA may be associated with worse outcomes. We evaluated the association between hypotension duration during MT and the 90 day functional outcome under both anesthetic regimens. METHODS: Patients were included in this retrospective study if they had an ischemic stroke treated by MT under GA or CS. The main exposure variable was the time below 90% of the reference value of arterial pressure measured before MT. The primary outcome was poor functional outcome defined as a 90 day modified Rankin Score ≥3. RESULTS: 371 patients were included in the study. GA was performed in 42%. A linear association between the duration of arterial hypotension and outcome was observed. The odds ratio for poor functional outcome of 10 min under 90% of the baseline mean arterial pressure was 1.13 (95% CI 1.06 to 1.21) without adjustment and 1.11 (95% CI 1.02 to 1.21) after adjustment for confounding factors. The functional outcome was poorer for patients treated under GA compared with CS, but the association with the depth of hypotension remained similar under both conditions. CONCLUSION: In this study, we observed a linear association between the duration of hypotension during MT and the functional outcome at 90 days. An aggressive and personalized strategy for the treatment of hypotension should be considered. Further trials should be conducted to address this question.

Impact of Local Infiltration Analgesia on the Quality of Recovery After Anterior Total Hip Arthroplasty: A Randomized, Triple-Blind, Placebo-Controlled Trial.

BACKGROUND: Local infiltration analgesia (LIA) is commonly used in anterior total hip arthroplasty (THA) surgery; however, evidence for its efficacy is lacking. We hypothesized that LIA with 0.2% ropivacaine when compared with injection of placebo (0.9% saline) would improve patient quality of recovery on postoperative day (POD) 1, as measured by the Quality of Recovery-15 (QoR-15) score. METHODS: Patients scheduled to have a primary unilateral anterior THA with a single surgeon in a tertiary level metropolitan hospital were randomized to receive LIA with either 2.5 mL/kg of 0.2% ropivacaine or 0.9% saline as placebo. Patients and clinical and study personnel were blinded to group allocation. Perioperative care was standardized and this included spinal anesthesia and oral multimodal analgesia. The primary outcome was a multidimensional (pain, physical comfort, physical independence, emotions, and psychological support) patient-reported quality of recovery scale, QoR-15, measured on POD 1. RESULTS: One hundred sixty patients were randomized; 6 patients were withdrawn after randomization and 2 patients had incomplete outcome data. The intention-to-treat analysis included 152 patients. The median (interquartile range [IQR]) QoR-15 score on POD 1 of the ropivacaine group was 119.5 (102-124), compared with the placebo group which had a median (IQR) of 115 (98-126). The median difference of 2 (95% confidence interval [CI], -4 to 7; P = .56) was not statistically or clinically significant. An as-per-protocol sensitivity analysis of 146 patients who received spinal anesthesia without general anesthesia, and the allocated intervention, also showed no evidence of a significant difference between groups. Secondary outcomes (worst pain numerical rating scale at rest and with movement on POD 1, opioid consumption on PODs 1 and 2, mobilization on POD 1, Brief Pain Inventory severity and interference on POD 90, and length of stay) were similar in both groups. CONCLUSIONS: LIA with 0.2% ropivacaine when compared with 0.9% saline as placebo did not improve quality of recovery 1 day after anterior THA.

[Initial Experience of a TAVI Program: Analysis of the Anesthetic Decision and its Evolution]. / Experiência Inicial de um Programa de TAVI: Análise da Decisão Anestésica e sua Evolução.

INTRODUCTION: Transcatheter aortic valve implantation is a less invasive option for aortic valve replacement. The number of transcatheter aortic valve implantations under local anesthesia with sedation has been increasing as the team's experience increases and less invasive accesses are used. The aim of this study is to describe the evolution of the anesthetic technique in patients undergoing transcatheter aortic valve implantation at our center over the years, as which was compared. MATERIAL AND METHODS: Retrospective study in 149 consecutive patients undergoing transcatheter aortic valve implantation in Hospital Santa Marta (January 2010 to December 2016). Data was collected from the periprocedural records of patients. Patients were stratified according to anesthetic technique. RESULTS: From our patients' sample, 57.0% were female, with median age 82 [58 - 95] years. Most patients underwent general anesthesia (68.5%). In the local anesthesia with sedation group there was a shorter duration of the procedure (120; [60 - 285] vs 155 [30 - 360]) and a lower number of patients requiring administration of vasopressors (61.8% vs 28.3%) - p < 0.05. There were no differences regarding length of hospital stay (9 [4 - 59] vs 10 [3 - 87]), periprocedural complications (66.0% vs 72.5%), readmission rate (4.3% vs 3.9%) or 30-days (2.1% vs 4.9%) and 1-year mortality (6.4% vs 7.8%) - p < 0.05. There was an increasing number of transcatheter aortic valve implantations performed under local anesthesia with sedation over the years. DISCUSSION: The choice of anesthetic technique depends on the patient's characteristics, experience and preference of the team. CONCLUSION: Local anesthesia with sedation seems to be associated with similar results as general anesthesia. The increase in the number of transcatheter aortic valve implantations under local anesthesia with sedation seems to follow the trend of lower invasiveness of the procedure.

Introdução: A implantação percutânea de válvula aórtica constitui uma opção menos invasiva de substituição valvular. O número de procedimentos sob anestesia local com sedação tem vindo a crescer com o aumento da experiência da equipa e os acessos cada vez menos invasivos. O trabalho tem como objetivo a descrição da evolução da técnica anestésica utilizada nos doentes submetidos a implantação percutânea de válvula aórtica no nosso centro ao longo dos anos, e sua comparação. Material e Métodos: Estudo retrospetivo em 149 doentes consecutivos submetidos a implantação percutânea de válvula aórtica no Hospital de Santa Marta (janeiro de 2010 a dezembro de 2016). Os dados foram colhidos a partir dos registos peri-procedimento e estratificados de acordo com a técnica anestésica. Resultados: Da amostra recolhida, 57,0% dos doentes eram do sexo feminino, com mediana idade 82 [58 - 95] anos. A maioria dos doentes foi submetida a anestesia geral (68,5%). Verificou-se menor duração do procedimento (120 [60 - 285] vs 155 [30 - 360]) e menor número de doentes com necessidade de administração de vasopressores na implantação percutânea de válvula aórtica (61,8% vs 28,3%) ­ p < 0,05. Não se registaram diferenças referentes à duração do internamento (9 [4 - 59] vs 10 [3 - 87]), complicações periprocedimento (66,0% vs 72,5%), reinternamento (4,3% vs 3,9%), mortalidade aos 30 dias (2,1% vs 4,9%) e 1 ano (6,4% vs 7,8%) ­ p > 0,05. O número de implantações percutâneas de válvula aórtica realizados sob anestesia local com sedação aumentou ao longo dos anos. Discussão: A escolha da técnica anestésica tende a variar consoante as características do doente, a experiência e preferência da equipa. Conclusão: Os resultados da anestesia local com sedação são similares aos da anestesia geral, tendo o aumento do número de procedimentos de implantação percutânea de válvula aórtica sob anestesia local com sedação acompanhado a tendência de menor invasibilidade do procedimento.

Bupivacaine infiltration in children for postoperative analgesia after tonsillectomy: A randomised controlled trial.

BACKGROUND: Adenotonsillectomy is a frequently performed procedure in paediatric day-case surgery. Postoperative pain can be significant and standard analgesia protocols are often insufficient. OBJECTIVE: Our primary objective was to investigate if infiltration of the peritonsillar space with bupivacaine would reduce the need for postoperative opioids compared with pre-emptive intravenous tramadol. DESIGN: A double-blind, randomised controlled trial. SETTING: Ambulatory surgical day care centre, University Hospitals of Leuven, Belgium, from January 2012 to September 2016. PATIENTS: Two hundred children, between 4 and 10 years old, undergoing elective adenotonsillectomy were included in the study. INTERVENTION: Children were randomly allocated to receive either a bolus of 3 mg kg intravenous tramadol or infiltration of the tonsillar lodge with 5-ml bupivacaine 0.25%. Reasons for exclusion were American Society of Anesthesiologists classification greater than 2, allergies to the investigated products, psychomotor retardation, bleeding disorders and lack of proficiency in Flemish. MAIN OUTCOME MEASURES: The primary endpoint was the number of children in need of piritramide postoperatively. Secondary outcomes included the cumulative dose of postoperative piritramide, pain scores and the incidence of postoperative nausea and vomiting during the first 24 postoperative hours, time to discharge and adverse effects. RESULTS: The proportion of children in need of postoperative piritramide was significantly lower in the tramadol group than in children with peritonsillar infiltration (57 vs. 81%, P < 0.001). When in need of postoperative piritramide, the tramadol-group required a significantly lower dose (median [IQR] 0.7 [0.6 to 1] vs. 1 [0.6 to 1.5] mg, P < 0.007) and had lower pain scores during the first 60 min after surgery. There were no statistically significant differences in postoperative nausea and vomiting incidence, need for antiemetics or complications. CONCLUSION: Compared with peritonsillar infiltration, preemptive intravenous tramadol decreases the need for postoperative opioids after tonsillectomy in children without increasing the incidence of side effects. TRIAL REGISTRATION: EudraCT 2011-005467-25.

The Use of Regional or Local Anesthesia for Carotid Endarterectomies May Reduce Blood Loss and Pulmonary Complications.

OBJECTIVE: Over 150,000 carotid endarterectomy (CEA) procedures are performed each year. Perioperative anesthetic management may be complex due to multiple patient and procedure-related risk factors. The authorsaimed to determine whether the use of general anesthesia (GA), when compared with regional anesthesia (RA), would be associated with reduced perioperative morbidity and mortality in patients undergoing a CEA. DESIGN: Retrospective analysis of the American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database. SETTING: The authors evaluated patients undergoing a CEA at multiple university- and community-based settings. PARTICIPANTS: A total of 43,463 patients were identified; 22,845 patients were propensity matched after excluding for missing data. INTERVENTIONS: The study population was divided into 2 groups: patients undergoing RA or GA. The RA group included regional anesthesia performed by the anesthesiologist or surgeon, monitored anesthesia care, and local infiltration. METHODS: The primary endpoint was 30-day mortality. Secondary endpoints included surgical site infection, pulmonary complications, return to the operating room, acute kidney injury, cardiac arrest, urinary tract infection, myocardial infarction, thromboembolism, perioperative transfusion, sepsis, and days to discharge. MEASUREMENTS AND MAIN RESULTS: Younger age, Hispanic ethnicity, body mass index <18.5, dyspnea, chronic obstructive pulmonary disease, and smoking history were associated with receiving GA. Patients with low hematocrit and low platelets were more likely to get RA. There was no mortality difference. GA was associated with a significantly higher rate of perioperative transfusions (p = 0.037) and perioperative pneumonia (p = 0.027). CONCLUSION: The use of RA over GA in CEA is associated with decreased risk of postoperative pneumonia and a reduced need for perioperative blood transfusions.

New local anesthetics.

Local anesthetics are used for performing various regional anesthesia techniques to provide intraoperative anesthesia and analgesia, as well as for the treatment of acute and chronic pain. Older medications such as lidocaine and bupivacaine as well as newer ones such as mepivacaine and ropivacaine are being used successfully for decades. Routes of administration include neuraxial, perineural, intravenous, various infiltrative approaches, topical, and transdermal. There are new innovations with the use of older local anesthetics in a novel manner, in addition to the development and use of new formulations. This chapter seeks to summarize the pharmacokinetics of local anesthetics and address the role of newer local anesthetics, as well as clinical implications, safety profiles, and the future of local anesthetic research. Finally, some clinical pearls are highlighted.

Effect of local infiltration analgesia, peripheral nerve blocks, general and spinal anesthesia on early functional recovery and pain control in unicompartmental knee arthroplasty.

BACKGROUND: The aim of the study was to analyze the effect of local infiltration analgesia (LIA), peripheral nerve blocks, general and spinal anesthesia on early functional recovery and pain control in primary unicompartmental knee arthroplasty (UKA). METHODS: Between January 2016 until August 2016, 134 patients underwent primary UKA and were subdivided into four groups according to their concomitant pain and anesthetic procedure with catheter-based techniques of femoral and sciatic nerve block (group GA&FNB, n = 38) or epidural catheter (group SP&EPI, n = 20) in combination with general anesthesia or spinal anesthesia, respectively, and LIA combined with general anesthesia (group GA&LIA, n = 46) or spinal anesthesia (group SP&LIA, n = 30). Outcome parameters focused on the evaluation of pain (NRS scores), mobilization, muscle strength and range of motion up to 7 days postoperatively. The cumulative consumption of (rescue) pain medication was analyzed. RESULTS: The LIA groups revealed significantly lower (about 50%) mean NRS scores (at rest) compared to the catheter-based groups at the day of surgery. In the early postoperative period, the dose of hydromorphone as rescue pain medication was significantly lower (up to 68%) in patients with SP&EPI compared to all other groups. No significant differences could be detected with regard to grade of mobilization, muscle strength and range of motion. However, there seemed to be a trend towards improved mobilization and muscle strength with general anesthesia and LIA, whereof general anesthesia generally tended to ameliorate mobilization. CONCLUSIONS: Except for a significant lower NRS score at rest in the LIA groups at day of surgery, pain relief was comparable in all groups without clinically relevant differences, while the use of opioids was significantly lower in patients with SP&EPI. A clear clinically relevant benefit for LIA in UKA cannot be stated. However, LIA offers a safe and effective treatment option comparable to the well-established conventional procedures.

Effect of local infiltration analgesia, peripheral nerve blocks, general and spinal anesthesia on early functional recovery and pain control in total knee arthroplasty.

BACKGROUND: Postoperative pain control and enhanced mobilization, muscle strength and range of motion following total knee arthroplasty (TKA) are pivotal requisites to optimize rehabilitation and early recovery. The aim of the study was to analyze the effect of local infiltration analgesia (LIA), peripheral nerve blocks, general and spinal anesthesia on early functional recovery and pain control in primary total knee arthroplasty. METHODS: Between January 2016 until August 2016, 280 patients underwent primary TKA and were subdivided into four groups according to their concomitant pain and anesthetic procedure with catheter-based techniques of femoral and sciatic nerve block (group GA&FNB, n = 81) or epidural catheter (group SP&EPI, n = 51) in combination with general anesthesia or spinal anesthesia, respectively, and LIA combined with general anesthesia (group GA&LIA, n = 86) or spinal anesthesia (group SP&LIA, n = 61). Outcome parameters focused on the evaluation of pain (NRS scores), mobilization, muscle strength and range of motion up to 7 days postoperatively. The cumulative consumption of (rescue) pain medication was analyzed. RESULTS: Pain relief was similar in all groups, while the use of opioid medication was significantly lower (up to 58%) in combination with spinal anesthesia, especially in SP&EPI. The LIA groups, in contrast, revealed significant higher mobilization (up to 26%) and muscle strength (up to 20%) in the early postoperative period. No analgesic technique-related or surgery-related complications occurred within the first 7 days. Due to insufficient pain relief, 8.4% of the patients in the catheter-based groups and 12.2% in the LIA groups resulted in a change of the anesthetics pain management. CONCLUSIONS: The LIA technique offers a safe and effective treatment option concerning early functional recovery and pain control in TKA. Significant advantages were shown for mobilization and muscle strength in the early postoperative period while pain relief was comparable within the groups.

Do Hospitals Performing Frequent Neuraxial Anesthesia for Hip and Knee Replacements Have Better Outcomes?

BACKGROUND: Neuraxial anesthesia is increasingly recommended for hip/knee replacements as some studies show improved outcomes on the individual level. With hospital-level studies lacking, we assessed the relationship between hospital-level neuraxial anesthesia utilization and outcomes. METHODS: National data on 808,237 total knee and 371,607 hip replacements were included (Premier Healthcare 2006 to 2014; 550 hospitals). Multivariable associations were measured between hospital-level neuraxial anesthesia volume (subgrouped into quartiles) and outcomes (respiratory/cardiac complications, blood transfusion/intensive care unit need, opioid utilization, and length/cost of hospitalization). Odds ratios (or percent change) and 95% CI are reported. Volume-outcome relationships were additionally assessed by plotting hospital-level neuraxial anesthesia volume against predicted hospital-specific outcomes; trend tests were applied with trendlines' R statistics reported. RESULTS: Annual hospital-specific neuraxial anesthesia volume varied greatly: interquartile range, 3 to 78 for hips and 6 to 163 for knees. Increasing frequency of neuraxial anesthesia was not associated with reliable improvements in any of the study's clinical outcomes. However, significant reductions of up to -14.1% (95% CI, -20.9% to -6.6%) and -15.6% (95% CI, -22.8% to -7.7%) were seen for hospitalization cost in knee and hip replacements, respectively, both in the third quartile of neuraxial volume. This coincided with significant volume effects for hospitalization cost; test for trend P < 0.001 for both procedures, R 0.13 and 0.41 for hip and knee replacements, respectively. CONCLUSIONS: Increased hospital-level use of neuraxial anesthesia is associated with lower hospitalization cost for lower joint replacements. However, additional studies are needed to elucidate all drivers of differences found before considering hospital-level neuraxial anesthesia use as a potential marker of quality.

Pharmacokinetics of 400 mg Locally Infiltrated Ropivacaine After Total Knee Arthroplasty Without Perioperative Tourniquet Use.

BACKGROUND AND OBJECTIVES: Local infiltration analgesia (LIA) with ropivacaine for total knee arthroplasty (TKA) is increasingly used. Despite the high doses of ropivacaine, LIA is considered safe, and this perception is sustained by pharmacokinetic data demonstrating that maximum concentrations of ropivacaine stay well below the toxic threshold in plasma. These pharmacokinetic studies all involve TKA procedures with the use of a tourniquet. Recently, performing TKA without the use of a tourniquet is gaining popularity, but no pharmacokinetic data exist when LIA is administered for TKA without the use of a tourniquet. The purpose of this study was to describe the pharmacokinetic profile of a single-shot ropivacaine (200 mL 0.2%) and 0.75 mg epinephrine (1000 µg/mL) when used for LIA in patients for TKA without a tourniquet. METHODS: In this prospective cohort study, 20 patients treated with LIA for TKA without a tourniquet were studied. Plasma samples were taken at 20, 40, 60, 90, 120, 240, 360, 480, 600, 720, and 1440 minutes after local anesthetic infiltration, in which total and unbound ropivacaine concentrations were determined. RESULTS: Results are given as median (interquartile range [IQR]). Median peak ropivacaine concentration was 1.16 µg/mL (IQR, 0.46); median peak unbound ropivacaine concentration was 0.05 µg/mL (IQR, 0.02). The corresponding times to reach the maximum concentration for total and unbound ropivacaine were 360 (IQR, 240) and 360 (IQR, 360) minutes, respectively. CONCLUSIONS: Although great interindividual variability in ropivacaine concentration was found, both total and unbound maximum serum concentrations remained below the assumed systemic toxic thresholds in all samples. CLINICAL TRIAL REGISTRATION: This study was registered at Netherlands Trial Registry (http://www.trialregister.nl), trial ID NTR6306.

Interfascial Plane Blocks: Back to Basics.

Ultrasound-guided interfascial plane blocks are a recent development in modern regional anesthesia research and practice and represent a new route of transmission for local anesthetic to various anatomic locations, but much more research is warranted. Before becoming overtaken with enthusiasm for these new techniques, a deeper understanding of fascial tissue anatomy and structure, as well as precise targets for needle placement, is required. Many factors may influence the ultimate spread and quality of resulting interfascial plane blocks, and these must be understood in order to best integrate these techniques into contemporary perioperative pain management protocols.

Plasma Ropivacaine Concentrations Following Local Infiltration Analgesia in Total Knee Arthroplasty: A Pharmacokinetic Study to Determine Safety Following Fixed-Dose Administration.

BACKGROUND AND OBJECTIVES: The primary aim of this study was to examine the pharmacokinetics of ropivacaine in patients undergoing elective total knee arthroplasty with local infiltration analgesia as the primary analgesic method. We also sought to determine the incidence of biochemical toxicity through measurement of plasma ropivacaine concentrations over the first 24 hours postoperatively. METHODS: This was a prospective, observational study of 15 patients undergoing elective total knee arthroplasty. Local infiltration analgesia was administered by standard technique with 300 mg ropivacaine and epinephrine 5 µg/mL. Total ropivacaine concentrations were taken at specified time intervals in the 24 hours after tourniquet release and analyzed by liquid chromatography-mass spectrometry. RESULTS: Fifteen patients were enrolled into the study. The median peak ropivacaine concentration was 0.57 µg/mL, with a range of 0.32 to 0.88 µg/mL, and occurred between 6 and 24 hours. Age (P = 0.04), weight (P = 0.04), creatinine (P = 0.02), and female sex (P = 0.03) were important predictors of peak concentration. Age (P = 0.02), female sex (P = 0.01), and baseline α1 acid glycoprotein concentrations (P = 0.03) were important predictors for the area under the curve from a ropivacaine concentration versus time plot. CONCLUSIONS: The peak total ropivacaine concentration was below quoted toxic concentrations (2.2 µg/mL) in all patients. This peak occurred later than has previously been described in those undergoing neuraxial or peripheral nerve block, occurring between 6 and 24 hours. The influence of age, weight, and renal function on systemic ropivacaine concentration should be considered when planning local infiltration analgesia. Female sex is a factor that has not previously been associated with peak ropivacaine concentrations.

Analgesia of Combined Femoral Triangle and Obturator Nerve Blockade Is Superior to Local Infiltration Analgesia After Total Knee Arthroplasty With High-Dose Intravenous Dexamethasone.

BACKGROUND AND OBJECTIVES: High-dose intravenous dexamethasone reduces the postoperative opioid requirement and is often included in the multimodal analgesia strategy after total knee arthroplasty (TKA). Combined obturator nerve and femoral triangle blockade (OFB) reduces the opioid consumption and pain after TKA better than local infiltration analgesia (LIA). The question is whether preoperative high-dose intravenous dexamethasone would cancel out the superior analgesic effect of OFB compared with LIA. The aim was to evaluate the analgesic effect of OFB versus LIA after TKA when all patients received high-dose intravenous dexamethasone. METHODS: Eighty-two patients were randomly assigned either to OFB or LIA after primary unilateral TKA. All patients received 16 mg dexamethasone. Primary outcome was morphine consumption via patient-controlled analgesia during the first 20 postoperative hours. Secondary outcomes were pain, nausea, dizziness, and length of hospital stay. RESULTS: Seventy-four patients were included in the analysis. Median total intravenous morphine consumption during the first 20 postoperative hours was 6 mg (interquartile range [IQR], 2-18 mg) in the OFB group and 20 mg (IQR, 12-28 mg) in the LIA group. The 14-mg difference (95% confidence interval, 6.4-18.0 mg) was significant (P < 0.001). There was no difference in pain score at rest at 20 hours postoperatively: 2 (IQR, 1-4) in the OFB group and 3 (IQR, 2-5) in the LIA group. CONCLUSIONS: Combined OFB reduces morphine consumption better than LIA after TKA even when all patients received high-dose intravenous dexamethasone. CLINICAL TRIAL REGISTRATION: This study was registered at ClinicalTrials.gov, identifier NCT02374008.

The Science of Local Anesthesia: Basic Research, Clinical Application, and Future Directions.

Local anesthetics have been used clinically for more than a century, but new insights into their mechanisms of action and their interaction with biological systems continue to surprise researchers and clinicians alike. Next to their classic action on voltage-gated sodium channels, local anesthetics interact with calcium, potassium, and hyperpolarization-gated ion channels, ligand-gated channels, and G protein-coupled receptors. They activate numerous downstream pathways in neurons, and affect the structure and function of many types of membranes. Local anesthetics must traverse several tissue barriers to reach their site of action on neuronal membranes. In particular, the perineurium is a major rate-limiting step. Allergy to local anesthetics is rare, while the variation in individual patient's response to local anesthetics is probably larger than previously assumed. Several adjuncts are available to prolong sensory block, but these typically also prolong motor block. The 2 main research avenues being followed to improve action of local anesthetics are to prolong duration of block, by slow-release formulations and on-demand release, and to develop compounds and combinations that elicit a nociception-selective blockade.

Anesthesia-Related Outcomes for Endovascular Stroke Revascularization: A Systematic Review and Meta-Analysis.

BACKGROUND AND PURPOSE: There is currently controversy on the ideal anesthesia strategy during mechanical thrombectomy for acute ischemic stroke. We performed a systematic review and meta-analysis of studies comparing clinical and angiographic outcomes of patients undergoing general anesthesia (GA group) and those receiving either local anesthesia or conscious sedation (non-GA group). METHODS: A literature search on anesthesia and endovascular treatment of acute ischemic stroke was performed. Using random-effects meta-analysis, we evaluated the following outcomes: recanalization rate, good functional outcome at 90 days (modified Rankin Score≤2), symptomatic intracranial hemorrhage, death, vascular complications, respiratory complications, procedure time, and time to groin puncture. RESULTS: Twenty-two studies (3 randomized controlled trials and 19 observational studies), including 4716 patients (1819 GA and 2897 non-GA) were included. In the nonadjusted analysis, patients in the GA group had higher odds of death (odds ratio [OR], 2.02; 95% confidence interval [CI], 1.66-2.45) and respiratory complications (OR, 1.70; 95% CI, 1.22-2.37) and lower odds of good functional outcome (OR, 0.58; 95% CI, 0.48-0.64) compared with the non-GA group. There was no difference in procedure time between the 2 primary comparison groups. When adjusting for baseline National Institutes of Health Stroke Scale, GA was still associated with lower odds of good functional outcome (OR, 0.59; 95% CI, 0.29-0.94). When considering studies performed in the stent-retriever/aspiration era, there was no significant difference in good neurological outcome rates (OR, 0.84; 95% CI, 0.67-1.06). CONCLUSIONS: Acute ischemic stroke patients undergoing intra-arterial therapy may have worse outcomes when treated with GA as compared with conscious sedation/local anesthesia. However, major limitations of current evidence (ie, retrospective studies and selection bias) indicate a need for adequately powered, multicenter randomized controlled trials to answer this question.

Outcome of patients undergoing TAVR with and without the attendance of an anesthesiologist.

BACKGROUND: During the last few years there is a shift from performing Transcatheter Aortic Valve Replacement (TAVR) under general anesthesia towards conscious sedation and local anesthesia only. In the vast majority of centers, sedation is guided by a qualified anesthesiologist. In our center, all TAVR procedures are being performed under local anesthesia and mild sedation, however, since September 2014, a large portion of TAVR procedures are being performed under local anesthesia without the presence of an anesthesiologist. Here we compare 30days outcome of patients undergoing TAVR with and without the presence of anesthesiologist in the catheterization laboratory. METHODS AND RESULTS: From September 2014 through April 2016, 324 patients (mean age 82.8±6) with severe symptomatic aortic stenosis were assigned to transfemoral TAVR with (150 patients) or without (174 patients) the attendance of an anesthesiologist. Baseline clinical and echocardiographic characteristics were similar between the groups. No difference in procedural and 30-day mortality, vascular complications, and major/life threatening bleeding were observed between the groups (p>0.1, for all). CONCLUSIONS: The presence of an anesthesiologist in the catheterization laboratory during transfemoral TAVR procedures did not significantly change 30-day outcome.