Non-invasive hemoglobin estimation for preoperative anemia screening.

BACKGROUND: Preoperative anemia is common and associated with adverse postoperative outcomes. Assessment of hemoglobin concentrations may facilitate optimization prior to surgery. However, phlebotomy-based hemoglobin measurement may contribute to patient discomfort and iatrogenic blood loss, which makes non-invasive hemoglobin estimation attractive in this setting. STUDY DESIGN AND METHODS: This is a prospective study of adult patients presenting for preoperative evaluation before elective surgery at a tertiary care medical center. The Masimo Pronto Pulse CO-Oximeter was utilized to estimate blood hemoglobin concentrations (SpHb), which were then compared with hemoglobin concentrations obtained via complete blood count. Receiver operating curves were used to identify SpHb values maximizing specificity for anemia detection while meeting a minimum sensitivity of 80%. RESULTS: A total of 122 patients were recruited with a median (interquartile range) age of 66 (58, 72) years. SpHb measurements were obtained in 112 patients (92%). SpHb generally overestimated hemoglobin with a mean (± 1.96 × standard deviation) difference of 0.8 (-2.2, 3.9) g/dL. Preoperative anemia, defined by hemoglobin <12.0 g/dL in accordance with institutional protocol, was present in 22 patients (20%). The optimal SpHb cut-point to identify anemia was 13.5 g/dL: sensitivity 86%, specificity 81%, negative predictive value 96%, and positive predictive value 53%. Utilizing this cut-point, 60% (73/122) of patients could have avoided phlebotomy-based hemoglobin assessment, while an anemia diagnosis would have been missed in <3% (3/122). CONCLUSION: The use of SpHb devices for anemia screening in surgical patients is feasible with the potential to reliably rule-out anemia despite limited accuracy.

Preoperative Evaluation and Management of Patients With Select Chronic Gastrointestinal, Liver, and Renal Diseases.

Patients with chronic gastrointestinal, hepatic, and renal disease are frequently encountered in clinical practice. This is due in part to the rising prevalence of risk factors associated with these conditions. These patients are increasingly being considered for surgical intervention and are at higher risk for multiple perioperative complications. Many are able to safely undergo surgery but require unique considerations to ensure optimal perioperative care. In this review, we highlight relevant perioperative physiology and outline our approach to the evaluation and management of patients with select chronic gastrointestinal, hepatic, and renal diseases. A comprehensive preoperative evaluation with a multidisciplinary approach is often beneficial, and specialist involvement should be considered. Intraoperative and postoperative plans should be individualized based on the unique medical and surgical characteristics of each patient.

Intraoperative Fluid Management a Modifiable Risk Factor for Surgical Quality - Improving Standardized Practice.

OBJECTIVE: We aimed to determine a safe zone of intraoperative fluid management associated with the lowest postoperative complication rates without increased acute kidney injury (AKi) risk for elective colorectal surgery patients. BACKGROUND: To date, standard practice within institutions, let alone national expectations related to fluid administration, are limited. This fact has perpetuated a quality gap. METHODS: Elective colorectal surgeries between 2018 and 2020 were included. Unadjusted odds ratios (ORs) for postoperative ileus, prolonged LOS, and AKi were plotted against the rate of intraoperative RL infusion (mL/ kg/h) and total intraoperative volume. Binary logistic regression analysis, including fluid volumes as a confounder, was used to identify risk factors for postoperative complications. RESULTS: A total of 2900 patients were identified. Of them, 503 (17.3%) patients had ileus, 772 (26.6%) patients had prolonged LOS, and 240 (8.3%) patients had AKI. The intraoperative fluid resuscitation rate (mg/kg/h) was less impactful on postoperative ileus, LOS, and AKI than the total amount of intraoperative fluid. A total fluid administration range between 300 mL and 2.7 L was associated with the lowest complication rate. Total intraoperative RL ≥2.7 L was independently associated with a higher risk of ileus (adjusted OR 1.465; 95% confidence interval 1.154-1.858) and prolonged LOS (adjusted OR 1.300; 95% confidence interval 1.047-1.613), but not AKI. Intraoperative RL ≤300 mL was not associated with an increased risk of AKI. CONCLUSION: Total intraoperative RL ≥2.7 L was independently associated with postoperative ileus and prolonged LOS in elective colorectal surgery patients. A new potential standard for intraoperative fluids will require anesthesia case planning (complexity and duration) to ensure total fluid volume meets this new opportunity to improve care.

Complication rate of ultrasound-guided paravertebral block for breast surgery.

BACKGROUND AND OBJECTIVES: Thoracic paravertebral blockade is often used as an anesthetic and/or analgesic technique for breast surgery. With ultrasound guidance, the rate of complications is speculated to be lower than when using landmark-based techniques. This investigation aimed to quantify the incidence of pleural puncture and pneumothorax following non-continuous ultrasound-guided thoracic paravertebral blockade for breast surgery. METHODS: Patients who received thoracic paravertebral blockade for breast surgery were identified by retrospective query of our institution's electronic database over a 5-year period. Data collected included patient demographics, level of block, type and volume of local anesthetic, occurrence of pleural puncture, occurrence of pneumothorax, evidence of local anesthetic toxicity, and patient vital signs. The incidence of block complications, including pleural puncture, pneumothorax, and local anesthetic toxicity, were ascertained. RESULTS: 529 patients underwent 2163 thoracic paravertebral injections. Zero pleural punctures were identified during block performance; however, two patients were found to have a pneumothorax on postoperative chest X-ray (3.6 per 1000 surgeries, 95% CI 0.5 to 13.6; 0.9 per 1000 levels blocked, 95% CI 0.1 to 3.3). There were no cases of local anesthetic systemic toxicity or associated lipid emulsion therapy administration. CONCLUSIONS: Pneumothorax following non-continuous ultrasound-guided thoracic paravertebral block using a parasagittal approach is an uncommon occurrence, with a similar rate to pneumothorax following breast surgery alone.

A 3-arm randomized clinical trial comparing interscalene blockade techniques with local infiltration analgesia for total shoulder arthroplasty.

BACKGROUND: The ideal analgesic modality for total shoulder arthroplasty (TSA) remains controversial. We hypothesized that a multimodal analgesic pathway incorporating continuous interscalene blockade (ISB) provides better analgesic efficacy than both single-injection ISB and local infiltration analgesia. METHODS: This single-center, parallel, unblinded, randomized clinical trial evaluated 129 adults undergoing primary TSA. Patients were allocated to single-injection ISB, continuous ISB, or local infiltration analgesia. The primary outcome was the Overall Benefit of Analgesia Score (range, 0 [best] to 28 [worst]) on postoperative day 1. Additional outcomes included pain scores, opioid consumption, quality of life, and postoperative complications in the first 24 hours, at 3 months, and at 1 year. RESULTS: We analyzed 125 patients (42 with single-injection ISB, 41 with continuous ISB, and 42 with local infiltration analgesia). The Overall Benefit of Analgesia Score was significantly improved in the continuous group (median [25th percentile, 75th percentile], 0 [0, 2]) compared with the single-injection group (2 [1, 4]; P = .002) and local infiltration analgesia group (3 [2, 4]; P < .001). Pain scores were significantly lower in the continuous group compared with the local infiltration analgesia group (P < .001 for all time points) and after 12 hours from ward arrival compared with the single-injection group (median [25th percentile, 75th percentile], 1.0 [0.0, 2.8] vs. 2.5 [0.0, 4.0]; P = .016). After postanesthesia recovery discharge, opioid consumption (oral morphine equivalents) was significantly lower in the continuous group (median [25th percentile, 75th percentile], 7.5 mg [0.0, 25.0 mg]) than in the local infiltration analgesia group (30 mg [15.0, 52.5 mg]; P < .001) and single-injection group (17.6 mg [7.5, 45.5 mg]; P = .010). No differences were found across groups for complications, 3-month outcomes, and 1-year outcomes. CONCLUSION: Continuous ISB provides superior analgesia compared with single-injection ISB and local infiltration analgesia in the first 24 hours after TSA.

Early Diuresis After Colon and Rectal Surgery Does Not Reduce Length of Hospital Stay: Results of a Randomized Trial.

BACKGROUND: Excessive perioperative fluid administration likely increases postoperative cardiovascular, infectious, and GI complications. Early administration of diuretics after elective surgery facilitates rapid mobilization of excess fluid, potentially leading to decreased bowel edema, more rapid return of bowel function, and reduced length of hospital stay. OBJECTIVE: This study aimed to evaluate the benefit of early diuresis after elective colon and rectal surgery in the setting of an enhanced recovery after surgery practice. DESIGN: This was a prospective study. SETTINGS: The study was conducted at a quaternary referral center. PATIENTS: A randomized, open-label, parallel-group trial was conducted in patients undergoing elective colon and rectal surgery at a single quaternary referral center. INTERVENTION: The primary intervention was administration of intravenous furosemide plus enhanced recovery after surgery on postoperative day 1 and 2 versus enhanced recovery after surgery alone. MAIN OUTCOME MEASURES: The primary outcome was length of hospital stay. Secondary outcomes included 30-day readmission rate, time to stool output during hospitalization after surgery, and incidence of various complications within the first 48 hours of hospital stay. RESULTS: In total, 123 patients were randomly assigned to receive either furosemide plus enhanced recovery after surgery (n = 62) or enhanced recovery after surgery alone (n = 61). Groups were evenly matched at baseline. At interim analysis, length of hospital stay was not superior in the intervention group (80.6 vs 99.6 hours, p = 0.564). No significant difference was identified in the rates of nasogastric tube replacement (1.6% vs 9.7%, p = 0.125). Time to return of bowel function was significantly longer in the intervention group (45.4 vs 48.8 hours, p = 0.048). The decision was made to end the study early because the conditional power of the study favored futility. LIMITATIONS: This was a single-center study. CONCLUSIONS: Early administration of furosemide does not significantly reduce the length of hospital stay after elective colon and rectal surgery in the setting of enhanced recovery after surgery practice. See Video Abstract at http://links.lww.com/DCR/A714.

Efficacy and Outcomes of Intrathecal Analgesia as Part of an Enhanced Recovery Pathway in Colon and Rectal Surgical Patients.

PURPOSE: Multimodal analgesia is an essential component of an enhanced recovery pathway (ERP). An ERP that includes the use of single-injection intrathecal analgesia (IA) has been shown to decrease morbidity and cost and shorten length of stay (LOS). Limited data exist on safety, feasibility, and the optimal IA regimen. Our objective was to characterize the efficacy, safety, and feasibility of IA within an ERP in a cohort of colorectal surgical patients. METHODS: We performed a retrospective review of all consecutive patients aged ≥ 18 years who underwent open or minimally invasive colorectal surgery from October 2012 to December 2013. All patients were enrolled in an institutional ERP that included the use of single-injection IA. Demographics, anesthetic management, efficacy (pain scores and opiate consumption), postoperative ileus (POI), adverse effects, and LOS are reported. RESULTS: 601 patients were identified. The majority received opioid-only IA (91%) rather than a multimodal regimen. Median LOS was 3 days. Overall rate of ileus was 16%. Median pain scores at 4, 8, 16, 24, and 48 hours were 3, 2, 3, 4, and 3, respectively. There was no difference in postoperative pain scores, LOS, or POI based on intrathecal medication or dose received. Overall, development of respiratory depression (0.2%) or pruritus (1.2%) was rare. One patient required blood patch for postdural headache. CONCLUSION: Intrathecal analgesia is safe, feasible, and efficacious in the setting of ERP for colorectal surgery. All regimens and doses achieved a short LOS, low pain scores, and a low incidence of POI. This trial is registered with Clinicaltrails.gov NCT03411109.

Complications After Continuous Posterior Lumbar Plexus Blockade for Total Hip Arthroplasty: A Retrospective Cohort Study.

BACKGROUND AND OBJECTIVES: While benefits of regional anesthesia in total hip arthroplasty (THA) are well documented, data describing the incidence of complications related to the use of posterior lumbar plexus blockade for THA remain limited. Our primary aim was to evaluate the incidence of infectious, bleeding, and neurological complications related specifically to the use of continuous posterior lumbar plexus block for elective THA. METHODS: We reviewed the electronic medical records of all adult patients who underwent elective THA with continuous posterior lumbar plexus blockade between December 1, 2004, and April 30, 2015, using the Mayo Clinic Total Joint Registry. All complications were verified via manual chart review by 2 reviewers. Patient demographics, type of surgery, and complications were analyzed. RESULTS: A total of 9649 patients who underwent 11,395 THA procedures met the inclusion criteria. There were 8686 (76.2%) primary and 2709 (23.8%) revision THAs. There were no block-related infections (0.00%; 95% confidence interval [CI], 0.00%-0.03%) and only 1 block-related hematoma (0.01%; 95% CI, 0.00%-0.05%) in a patient with multiple risk factors for bleeding. There were 60 (0.53%; 95% CI, 0.40%-0.68%) perioperative nerve injuries. Forty-three were in the sciatic distribution (71.67%; incidence, 0.38%). Although there were no documented overt iatrogenic nerve injuries, the posterior lumbar plexus blockade could not be excluded as the potential cause in 9 cases (incidence, 0.08%) based on clinical distribution or electromyographic findings. CONCLUSIONS: In our large, single-center cohort study, we report no catheter-related infections, whereas catheter-related hemorrhagic and neurological complications also appear to be rare.

Perioperative Nerve Injury After Peripheral Nerve Block in Patients With Previous Systemic Chemotherapy.

BACKGROUND AND OBJECTIVES: There are multiple risk factors for developing perioperative nerve injury (PNI). Perioperative nerve injury after peripheral nerve blockade (PNB) is rare. Exposure to systemic chemotherapy may cause peripheral neuropathy, but its role as a risk factor for PNI after PNB is unknown. The objective of this retrospective study was to determine the incidence of PNI in patients undergoing PNB as part of extremity surgery after prior exposure to systemic chemotherapy. METHODS: All patients aged 18 years or older who received systemic chemotherapy and subsequently underwent PNB were identified. The primary outcome was defined as the presence of new or worsened PNI documented within 3 months of the procedural date. Cases of PNI were independently reviewed by 3 investigators, and the etiology of all PNI cases were categorized as possibly or unlikely related to the PNB. RESULTS: A total of 216 PNB (165 lower extremity blocks, 51 upper extremity blocks) were performed in 186 patients previously exposed to chemotherapy; 4 cases met criteria for PNI (2.2%; 95% confidence interval, 0.8%-5.4%). One case of PNI was possibly related to PNB (0.5%; 95% confidence interval, 0.1%-3.0%) and 3 cases were unlikely related to PNB. Complete recovery occurred in 3 cases, with partial recovery occurring in 1. CONCLUSIONS: The overall incidence of PNI in this cohort (2.2%) was not different than baseline risk established in large cohort studies. Perioperative nerve injury was possibly attributable to the PNB in 0.5% of patients. However, in the absence of a control group of surgical patients who previously received systemic chemotherapy without regional anesthesia, we cannot determine whether the higher incidence of neurologic injury is secondary to the surgical procedure, the anesthetic technique, the natural progression of chemotherapy-induced peripheral neuropathy, or a combination of factors and the relative contribution of each.

Safety of an Enhanced Recovery Pathway for Patients Undergoing Open Hepatic Resection.

BACKGROUND: Enhanced recovery pathways (ERP) have not been widely implemented for hepatic surgery. The aim of this study was to evaluate the safety of an ERP for patients undergoing open hepatic resection. METHODS: A single-surgeon, retrospective observational cohort study was performed comparing the clinical outcomes of patients undergoing open hepatic resection treated before and after implementation of an ERP. Morbidity, mortality, and length of hospital stay (LOS) were compared between pre-ERP and ERP groups. RESULTS: 126 patients (pre-ERP n = 73, ERP n = 53) were identified for the study. Patient characteristics and operative details were similar between groups. Overall complication rate was similar between pre-ERP and ERP groups (37% vs. 28%, p = 0.343). Before and after pathway implementation, the median LOS was similar, 5 (IQR 4-7) vs. 5 (IQR 4-6) days, p = 0.708. After adjusting for age, type of liver resection, and ASA, the ERP group had no increased risk of major complication (OR 0.38, 95% CI 0.14-1.02, p = 0.055) or LOS greater than 5 days (OR 1.21, 95% CI 0.56-2.62, p = 0.627). CONCLUSIONS: Routine use of a multimodal ERP is safe and is not associated with increased postoperative morbidity after open hepatic resection.

Current tobacco use is associated with higher rates of implant revision and deep infection after total hip or knee arthroplasty: a prospective cohort study.

BACKGROUND: Tobacco smoking is a risk factor for several adverse post-operative outcomes. We aimed to compare the rates of complications in current tobacco users and non-users who underwent primary total hip arthroplasty (THA) or total knee arthroplasty (TKA). METHODS: All patients who underwent primary THA or TKA at the Mayo Clinic from 2010-2013 were included in the study. Current tobacco use was defined as the use of cigarettes, cigars, pipes, or smokeless tobacco reported at the time of index THA or TKA; current non-users were former users or never users. We used Cox proportional hazards regression to assess the association of current tobacco use status with each post-THA/TKA complication, using hazard ratios and 95% confidence intervals (CI). RESULTS: Tobacco use status was available for 7926 patients (95%) and not available for 446 patients (5%); 565 (7%) were current tobacco users. Compared to non-users, current tobacco users were more likely to be male (p < 0.001), and less likely to be obese (p ≤ 0.008), be older than 60 years, have Charlson score >0 or have undergone TKA rather than THA (p < 0.001 each). The hazard ratios for deep infection (2.37; 95% CI 1.19, 4.72; p = 0.01) and implant revision (1.78; 95% CI 1.01, 3.13; p = 0.04) were higher in current tobacco users than in non-users. No significant differences were noted for periprosthetic fractures or superficial infections. CONCLUSIONS: We noted that current tobacco use was associated with high risk of deep infection and implant revision after primary THA or TKA. Future studies should determine the optimal time for tobacco use cessation before elective surgeries such as THA and TKA to improve short-term and long-term arthroplasty outcomes.

Does Intravenous Midazolam Dose Influence the Duration of Recovery Room Stay Following Outpatient Third Molar Surgery?

PURPOSE: To evaluate the impact of intravenous midazolam dose on the duration of recovery room stay for patients undergoing outpatient third molar surgery. MATERIALS AND METHODS: Using a retrospective cohort study design, a sample of patients undergoing outpatient third molar surgery under intravenous sedation at Mayo Clinic from 2010 to 2014 was identified. All patients underwent extraction of all 4 third molars during a single operative procedure and the age range was limited to 14 to 29 years. The primary predictor variable was the total dose of intravenous midazolam administered during sedation. The primary outcome variable was recovery room length of stay (LOS) after completion of surgery. Multiple covariates also abstracted included patient age, gender, American Society of Anesthesiologists (ASA) score, duration of surgical procedure, complexity of surgical procedure, types and dosages of all intravenous medications administered during sedation, and volume of crystalloid fluid administered perioperatively. Univariable and multivariable models were developed to evaluate associations between the primary predictor variable and covariates relative to the primary outcome variable. RESULTS: The study sample was composed of 2,610 patients. Mean age was 18.3 years (SD, 3.0 yr; range, 14 to 29 yr) and gender distribution was 52% female. Mean dosage of midazolam administered was 4.1 mg (SD, 1.1 mg; range, 0.5 to 10.0 mg). Variables predicting shorter LOS at multivariable analysis included older age (P < .001), male gender (P = .004), and administration of larger crystalloid fluid volumes (P < .001). Variables predicting longer LOS included higher ASA score (P < .001), administration of ketamine (P < .001), and administration of ketorolac (P < .001). The dose of midazolam administered during sedation was not found to be significantly associated with prolonged recovery room LOS in univariable or multivariable settings. CONCLUSION: Dosage of intravenous midazolam does not appear to significantly impact the duration of recovery room stay in the prototypical patients undergoing sedation for outpatient third molar surgery.

Continuing clopidogrel during elective total hip and knee arthroplasty: assessment of bleeding risk and adverse outcomes.

Limited research assessing risks of continued clopidogrel perioperatively in patients undergoing elective orthopedic procedures exists. Patients that underwent elective primary or revision total knee arthroplasty (TKA) or total hip arthroplasty (THA) from 2007 to 2012 while taking clopidogrel at the time of surgical evaluation were retrospectively identified. Patient demographics, last dose of clopidogrel, intraoperative blood loss, blood transfusion, and presence of 30-day adverse cardiac events (ACE) were collected. Of 142 patients meeting criteria, 24 (16.9%) patients remained on clopidogrel perioperatively. Patients that continued clopidogrel were more likely to receive a blood transfusion within 24 hours of surgery (31.8% vs. 7.7%; P=0.004) and during hospitalization (37.5% vs. 15.3%; P=0.02), but the incidence of 30-day ACE was not significantly different. Continuation of clopidogrel perioperatively for elective THA or TKA should be carefully considered.

Intrathecal analgesia and restrictive perioperative fluid management within enhanced recovery pathway: hemodynamic implications.

BACKGROUND: Intrathecal analgesia and avoidance of perioperative fluid overload are key items within enhanced recovery pathways. Potential side effects include hypotension and renal dysfunction. STUDY DESIGN: From January 2010 until May 2010, all patients undergoing colorectal surgery within enhanced recovery pathways were included in this retrospective cohort study and were analyzed by intrathecal analgesia (IT) vs none (noIT). Primary outcomes measures were systolic and diastolic blood pressure, mean arterial pressure, and heart rate for 48 hours after surgery. Renal function was assessed by urine output and creatinine values. RESULTS: One hundred and sixty-three consecutive colorectal patients (127 IT and 36 noIT) were included in the analysis. Both patient groups showed low blood pressure values within the first 4 to 12 hours and a steady increase thereafter before return to baseline values after about 24 hours. Systolic and diastolic blood pressure and mean arterial pressure were significantly lower until 16 hours after surgery in patients having IT compared with the noIT group. Low urine output (<0.5 mL/kg/h) was reported in 11% vs 29% (IT vs noIT; p = 0.010) intraoperatively, 20% vs 11% (p = 0.387), 33% vs 22% (p = 0.304), and 31% vs 21% (p = 0.478) for postanesthesia care unit and postoperative days 1 and 2, respectively. Only 3 of 127 (2.4%) IT and 1 of 36 (2.8%) noIT patients had a transitory creatinine increase >50%; no patients required dialysis. CONCLUSIONS: Postoperative hypotension affects approximately 10% of patients within an enhanced recovery pathway and is slightly more pronounced in patients with IT. Hemodynamic depression persists for <20 hours after surgery; it has no measurable negative impact and therefore cannot justify detrimental postoperative fluid overload.

Perioperative nerve injury after total hip arthroplasty: regional anesthesia risk during a 20-year cohort study.

BACKGROUND: Perioperative nerve injury (PNI) is a recognized complication of total hip arthroplasty (THA). Regional anesthesia (RA) techniques may increase the risk of neurologic injury. Using a retrospective cohort study, the authors tested the hypothesis that use of RA increases the risk for PNI after elective THA. METHODS: All adult patients who underwent elective THA at Mayo Clinic during a 20-yr period were included. The primary outcome was the presence of a new PNI within 3 months of surgery. Multivariable logistic regression was used to evaluate patient, surgical, and anesthetic risk factors for PNI. RESULTS: Of 12,998 patients undergoing THA, 93 experienced PNI (incidence = 0.72%; 95% CI 0.58-0.88%). PNI was not associated with type of anesthesia (OR = 0.72 for neuraxial-combined vs. general; 95% CI 0.46-1.14) or peripheral nerve blockade (OR = 0.65; 95% CI 0.34-1.21). The risk for PNI was associated with younger age (OR = 0.79 per 10-yr increase; 95% CI 0.69-0.90), female gender (OR = 1.72; 95% CI 1.12-2.64), longer operations (OR = 1.10 per 30-min increase; 95% CI 1.03-1.18) or posterior surgical approach (OR = 1.91 vs. anterior approach; 95% CI 1.22-2.99). Neurologic recovery was not influenced by the use of RA techniques in patients with PNI. CONCLUSIONS: The risk for PNI after THA was not increased with the use of neuraxial anesthesia or peripheral nerve blockade. Neurologic recovery in patients who experienced PNI was not affected by the use of RA. These results support the use of RA techniques in patients undergoing elective THA given their known functional and clinical benefits.

Perioperative seizures in patients with a history of a seizure disorder.

BACKGROUND: The occurrence of perioperative seizures in patients with a preexisting seizure disorder is unclear. There are several factors unique to the perioperative period that may increase a patient's risk of perioperative seizures, including medications administered, timing of medication administration, missed doses of antiepileptic medications, and sleep deprivation. We designed this retrospective chart review to evaluate the frequency of perioperative seizures in patients with a preexisting seizure disorder. METHODS: We retrospectively reviewed the medical records of all patients with a documented history of a seizure disorder who received an anesthetic between January 1, 2002 and December 31, 2007. Patients excluded from this study include those who had an outpatient procedure or intracranial procedure, ASA classification of V, pregnant women, and patients younger than 2 years of age. The first hospital admission of at least 24 hours during which an anesthetic was provided was identified for each patient. Patient demographics, character of the seizure disorder, details of the surgical procedure, and clinically apparent seizure activity in the perioperative period (within 3 days after the anesthetic) were recorded. RESULTS: During the 6-year study period, 641 patients with a documented seizure disorder were admitted for at least 24 hours after an anesthetic. Twenty-two patients experienced perioperative seizure activity for an overall frequency of 3.4%(95% confidence interval, 2.2%-5.2%). The frequency of preoperative seizures (P < 0.001) and the timing of the most recent seizure (P < 0.001) were both found to be significantly related to the likelihood of experiencing a perioperative seizure. As the number of antiepileptic medications increased, so did the frequency of perioperative seizures (P < 0.001). Neither the type of surgery nor the type of anesthetic (general anesthesia, regional anesthesia, or monitored anesthesia care) affected the frequency of perioperative seizures in this patient population. CONCLUSIONS: We conclude that the majority of perioperative seizures in patients with a preexisting seizure disorder are likely related to the patient's underlying condition. The frequency of seizures is not influenced by the type of anesthesia or procedure. Because patients with frequent seizures at baseline are likely to experience a seizure in the perioperative period, it is essential to be prepared to treat seizure activity regardless of the surgical procedure or anesthetic technique.

Role of regional anesthesia in the ambulatory environment.

The use of local anesthetics in ambulatory surgery offers multiple benefits in line with the goals of modern-day outpatient surgery. A variety of regional techniques can be used for a wide spectrum of procedures; all are shown to reduce postprocedural pain; reduce the short-term need for opiate medications; reduce adverse effects, such as nausea and vomiting; and reduce the time to dismissal compared with patients who do not receive regional techniques. Growth in ambulatory procedures will likely continue to rise with future advances in surgical techniques, changes in reimbursement, and the evolution of clinical pathways that include superior, sustained postoperative analgesia. Anticipating these changes in practice, the role of, and demand for, regional anesthesia in outpatient surgery will continue to grow.