A single center descriptive study of local anesthetic dose in knee arthroplasty: Was there evidence of local anesthetic systemic toxicity?

STUDY OBJECTIVE: Describe dosing of local anesthetic when both a periarticular injection (PAI) and peripheral nerve block (PNB) are utilized for knee arthroplasty analgesia, and compare the dosing of local to suggested maximum dosing, and look for evidence of local anesthetic systemic toxicity (LAST). DESIGN: A single center retrospective cohort study between May 2018 and November 2022. SETTING: A major academic hospital. PATIENTS: Patients who had both a PAI and PNB while undergoing primary, revision, total, partial, unilateral, or bilateral knee arthroplasty. INTERVENTIONS: None. MEASUREMENTS: Calculate the dose of local anesthetic given via PAI, PNB, and both routes combined as based on lean body weight and compare that to the suggested maximum dosing. Look for medications, clinical interventions, and critical event notes suggestive of a LAST event. MAIN RESULTS: There were 4527 knee arthroplasties where both a PAI and PNB were performed during the study period. When combining PAI and PNB doses, >75% of patients received more than the suggested maximum dose of 3 mg/kg lean body weight. The median local anesthetic dosing over the study period, 4.4 mg/kg (IQR 3.5,5.9), was 147% of the suggested maximum dose (IQR 117,197). There was no conclusive evidence of LAST among any of the patients in the study. CONCLUSIONS: Over the course of our study, we had 4527 knee arthroplasties with a median PAI and PNB local anesthetic dose that was 147% of the suggested maximum without any clear clinical evidence of a LAST event.

The role of methadone in cardiac surgery for management of postoperative pain.

Background: This retrospective study evaluated the efficacy and safety of intraoperative methadone compared with short-acting opioids. Methods: Patients undergoing cardiac surgery with cardiopulmonary bypass (n=11 967) from 2018 to 2023 from a single health system were categorised into groups based on intraoperative opioid administration: no methadone (Group O), methadone plus other opioids (Group M+O), and methadone only (Group M). Results: Patients in Groups M and M+O had lower mean pain scores until postoperative day (POD) 7 compared with Group O after adjusting for covariates (P<0.01). Both Groups M and M+O had lower total opioid administered compared with Group O for all days POD0-POD6 (all P<0.001). The median number of hours until initial postoperative opioid after surgery was 2.55 (inter-quartile range [IQR]=1.07-5.12), 6.82 (IQR=3.52-12.98), and 7.0 (IQR=3.82-12.95) for Group O, Group M+O, and Group M, respectively. The incidence of postoperative complications did not differ between groups. Conclusions: Intraoperative administration of methadone was associated with better pain control without significant side-effects after cardiac surgery.

Intrathecal Opioid Use in Kidney Transplantation: An Observational Cohort Study.

BACKGROUND: Kidney transplant is the most common transplant operation performed in the United States. Although various approaches to pain management have been described, the optimal analgesic strategy remains undefined. Specifically, the role of intrathecal opioids in this patient population has not been comprehensively evaluated. METHODS: Using a retrospective cohort design, data from kidney transplant operations at a single tertiary care medical center between August 1, 2017, and July 31, 2022, were extracted. Inverse probability of treatment weighting (IPTW) was used to assess differences in clinical outcomes based on the presence or absence of intrathecal opioid administration before surgical incision. The primary outcome was total opioid exposure expressed in milligram morphine equivalents (MME) in the first 72 hours postoperatively, with secondary outcomes including total MME (intraoperative plus postoperative MME, postoperative pain scores, and the presence of postoperative nausea/vomiting [PONV], pruritus, or adverse events). RESULTS: A total of 1014 kidney transplants in 1012 unique patients were included, with 411 (41%) receiving intrathecal opioids preoperatively. Hydromorphone was the intrathecal opioid used in all cases with median dose of 100 µg (interquartile range [IQR], 100, 100; range 50-200). Subjects receiving intrathecal opioids had significantly lower postoperative opioid requirements at 72 hours (30 [0-68] vs 64 [22, 120] MME), with ratio of geometric means in the IPTW analysis (ratio of geometric means 0.34, 95% confidence interval [CI], 0.26-0.43; P < .001). Similar findings were observed for total opioids (45 [30-75] vs 75 [60-90] MME; ratio of geometric means 0.58, 95% CI, 0.54-0.63; P < .001). Maximum reported pain scores in the intrathecal group were lower at 24 hours (4 [2-7] vs 7 [5, 8]; OR, 0.28; 95% CI, 0.21-0.37 for experiencing a higher pain score with intrathecal opioids, P < .001) and 72 hours (6 [4-7] vs 7 [5-8]; OR, 0.41; 95% CI, 0.31-0.54; P < .001). Patients receiving intrathecal opioids were more likely to experience PONV (225 of 411 [55%] vs 232 of 603 [38%]; OR, 2.16; 95% CI, 1.63-2.86; P < .001). CONCLUSIONS: Intrathecal opioid administration was associated with improved pain outcomes in patients undergoing kidney transplantation, including lower opioid requirements and pain scores through 72 hours. However, this was accompanied by an increased risk of PONV.

Retrospective Review of Intrathecal Hydromorphone Dose Range and Complications.

BACKGROUND: Optimal intrathecal dosing regimens for hydromorphone are not well established for analgesia after abdominal surgery. OBJECTIVES: We reviewed intrathecal hydromorphone doses and complications because dosing variability has been observed among anesthesiologists. We hypothesized that increasing doses of intrathecal hydromorphone would be associated with improved postoperative analgesia, but with increased rates of opioid-related adverse events. STUDY DESIGN: Retrospective analysis. SETTING: A high-volume academic referral center in the United States. METHODS: A retrospective study was conducted of adults undergoing abdominal surgery under general anesthesia supplemented preoperatively with intrathecal hydromorphone for postoperative analgesia from May 5, 2018, through May 31, 2021. Patients were categorized into 3 hydromorphone dosing groups: low-dose (50-100 µg), middle-dose (101-199 µg), and high-dose (200-300 µg). Multivariable logistic regression models were used to assess rates of severe postoperative pain, severe opioid-related adverse events, oversedation, and pruritus in the postanesthesia care unit (PACU) and within 24 hours after PACU discharge. RESULTS: Of 1,846 patients identified, 1,235 (66.9%) were in the low-dose group; 321 (17.3%), middle-dose group; and 290 (15.7%), high-dose group. Patients receiving the 2 higher doses had more extensive procedures. An unadjusted analysis showed differing rates of severe pain in the PACU by group: 306 (24.8%) in the low-dose, 73 (22.7%) middle-dose, and 45 (15.5%) in the high-dose group (P = 0.003); these differences, however, were no longer significant after an adjusted analysis (P = 0.34). Ten severe opioid-related events occurred; all were recognized in the PACU. Five events each occurred in the low-dose and high-dose groups versus none in the middle-dose group (P = 0.02). No other differences were identified with adjusted analyses. LIMITATIONS: Limitations of our study include its retrospective design and its conduct at a single center, along with the apparent, but difficult to characterize, treatment biases in hydromorphone dosing. CONCLUSIONS: No dose response was observed between intrathecal hydromorphone dose and postoperative analgesia, a finding that may reflect treatment bias. Higher rates of severe opioid-related events were detected for patients receiving high-dose hydromorphone in the PACU, but all other safety outcomes were similar between dosing regimens. KEY WORDS: Drug-related side effects, opioid analgesics, outcome assessment, postoperative pain, spinal injections.

Perioperative outcomes of patients with restless legs syndrome: a single-center retrospective review.

STUDY OBJECTIVES: There are multiple stressors in the perioperative period for patients with restless legs syndrome (RLS) that may be implicated in the worsening of symptoms. Our primary objective was to compare the perioperative course of patients with RLS to patients without the diagnosis. METHODS: This was a single-center, matched-cohort, retrospective chart review of patients with RLS undergoing inpatient procedures from 2015-2019 matched 1:1 with patients without the diagnosis. RESULTS: Patients with RLS had a higher comorbidity burden; specifically, pulmonary, renal, diabetes mellitus, and congestive heart failure. The perioperative course was notable for higher maximum pain scores for patients with RLS in the postanesthesia care unit (odds ratio, 1.29; 95% confidence interval, 1.19-1.40; P < .001). Postoperative patients with RLS also had higher maximum pain scores on postoperative days 0, 1, and 2. The odds of rapid-response calls were higher in patients with RLS (odds ratio, 1.43; 95% confidence interval, 1.18-1.73; P < .001). There were no other significant differences in postoperative complications. The odds of using RLS-triggering medications were lower in the RLS group (odds ratio, 0.85; 95% confidence interval, 0.78-0.92; P < .001). CONCLUSIONS: Our single-center retrospective review found that patients with RLS had higher pain scores in the postanesthesia care unit and on the first few postoperative days. Rapid-response team calls were more common in patients with RLS. RLS-triggering medications were significantly less likely to be used in patients with RLS. There were no significant differences in other postoperative events. CITATION: Gali B, Silber MH, Hanson AC, Portner E, Gay P. Perioperative outcomes of patients with restless legs syndrome: a single-center retrospective review. J Clin Sleep Med. 2022:18(7):1841-1846.

Ipsilateral Intravenous Catheter Placement in Breast Cancer Surgery Patients.

BACKGROUND: There is a continued perception that intravenous line (IV) placement is contraindicated in the arm ipsilateral to prior breast cancer surgery to avoid breast cancer-related lymphedema (BCRL). The aim of this retrospective study was to determine the risk for development of BCRL in ipsilateral arm IV placement compared to contralateral arm IV placement to prior breast cancer surgery. METHODS: We performed a retrospective review, via our Integrated Clinical Systems and Epic Electronic Heath Record of IV placement for anesthesia and surgery in patients with a prior history of breast cancer surgery with or without axillary lymph node dissection. Complication rates were compared for IVs placed in the ipsilateral and contralateral arms. We identified 3724 patients undergoing 7896 IV placements between January 1, 2015, and May 5, 2018, with a prior history of breast cancer surgery via their index anesthesia and surgical procedures. RESULTS: The median time from breast cancer surgery to IV placement was 1.5 years (range, 1 day to 17.8 years). Of 2743 IVs placed in the arm contralateral to prior breast cancer surgery, 2 had a complication, corresponding to an incidence of 7.3 per 10,000 (95% confidence interval [CI], 0.9-26.3 per 10,000). Of 5153 IVs placed in the arm ipsilateral to prior breast cancer surgery, 2 IVs had a complication, for an incidence of 3.9 per 10,000 (95% CI, 0.5-14.0 per 10,000). The frequency of complications was not found to differ significantly between the groups (P = .91), and the 95% CI for the risk difference (ipsilateral minus contralateral) was -23 to +8 complications per 10,000. The complication rate is similar when only the first IV placed following breast cancer surgery is considered (overall 5.4 per 10,000 [95% CI, 0.7-19.4] per 10,000; contralateral 7.0 [95% CI, 0.2-39.0] per 10,000, ipsilateral 4.4 [95% CI, 0.1-24.2] per 10,000; P = 1.00; 95% CI for risk difference [ipsilateral minus contralateral], -41 to +22 per 10,000). CONCLUSIONS: We found very few complications in patients who had an IV placed for surgery following a previous breast cancer surgery and no complications in those patients with IV placement ipsilateral with axillary node dissection. Avoidance of IV placement in the arm ipsilateral to breast cancer surgery is not necessary.

Sex-Specific Associations Between Preoperative Anemia and Postoperative Clinical Outcomes in Patients Undergoing Cardiac Surgery.

BACKGROUND: Preoperative anemia is common in cardiac surgery, yet there were limited data describing the role of sex in the associations between anemia and clinical outcomes. Understanding these relationships may guide preoperative optimization efforts. METHODS: This is an observational cohort study of adults undergoing isolated coronary artery bypass grafting or single- or double-valve surgery from 2008 to 2018 at a large tertiary medical center. Multivariable regression assessed the associations between preoperative hemoglobin concentrations and a primary outcome of postoperative acute kidney injury (AKI) and secondary outcomes of perioperative red blood cell (RBC) transfusion, reoperation, vascular complications (ie, stroke, pulmonary embolism, and myocardial infarction), and hospital length of stay (LOS). Each outcome was a single regression model, using interaction terms to assess sex-specific associations between hemoglobin and outcome. RESULTS: A total of 4117 patients were included (57% men). Linear splines with sex-specific knots (13 g/dL in women and 14 g/dL in men) provided the best overall fit for preoperative hemoglobin and outcome relationships. In women, each 1 g/dL decrease in hemoglobin <13 g/dL was associated with increased odds of AKI (odds ratio = 1.49; 95% confidence interval [CI], [1.23-1.81]; P < .001), and there was no significant association between hemoglobin per 1 g/dL >13 g/dL and AKI (0.90 [0.56-1.45]; P = .67). The association between hemoglobin and AKI in men did not meet statistical significance (1.10 [0.99-1.22]; P = .076, per 1 g/dL decrease <14 g/dL; 1.00 [0.79-1.26]; P = .98 for hemoglobin per 1 g/dL >14 g/dL). In women, lower preoperative hemoglobin (per 1 g/dL decrease <13 g/dL) was associated with increased odds of RBC transfusion (2.90 [2.33-3.60]; P < .001), reoperation (1.27 [1.11-1.45]; P < .001) and a longer hospital LOS (multiplicative increase in geometric mean 1.05 [1.03-1.07]; P < .001). In men, preoperative hemoglobin (per 1 g/dL decrease <14 g/dL) was associated with increased odds of perioperative RBCs (2.56 [2.27-2.88]; P < .001) and longer hospital LOS (multiplicative increase in geometric mean 1.02 [1.01-1.04] days; P < .001) but not reoperation (0.94 [0.85-1.04]; P = .256). Preoperative hemoglobin per 1 g/dL >13 g/dL in women and 14 g/dL in men were associated with lower odds of RBCs transfusion (0.57 [0.47-0.69]; P < .001 and 0.74 [0.60-0.91]; P = .005, respectively). CONCLUSIONS: Preoperative anemia was associated with inferior clinical outcomes after cardiac surgery. The associations between hemoglobin and outcomes were distinct for women and men, with different spline knot points identified (13 and 14 g/dL, respectively). Clinicians should consider data-driven approaches to determine preoperative hemoglobin values associated with increasing risk for adverse perioperative outcomes across sexes.

Three Risk Stratification Tools and Postoperative Pneumonia After Noncardiothoracic Surgery.

BACKGROUND: Postoperative in-hospital pneumonia is a serious complication. This study aims to investigate the association between 3 preoperative stratification tools (American Society of Anesthesiologists Physical Status [ASA-PS] score, Charlson Comorbidity Index [CCI], and Rockwood Frailty Deficit Index [FI]) and risk for postoperative pneumonia. METHODS: We identified adult patients who developed postoperative pneumonia following noncardiothoracic surgery under general anesthesia, between January 1, 2016 and December 31, 2017. Patients with postoperative pneumonia were 1:1 matched to control subjects based on age, sex, and the exact type of operations. Medical records were reviewed to identify variables that may be associated with risk for developing postoperative pneumonia. Analyses adjusted for clinical characteristics were performed using the conditional logistic regression, taking into account 1:1 matched set case-control study design. RESULTS: We identified 211 cases of postoperative pneumonia, and all 3 tested stratification tools were associated with increased risk: ASA-PS (after all adjustments of American Society of Anesthesiologists (ASA) III, odds ratio 4.17 [95% confidence interval 1.74-10.01]; ASA > III 24.03 [6.54-88.32]), CCI (CCI values > 3, 1.29 [1.02-1.63] per unit CCI score), and frail FI score 3.25 (1.45-7.27). Because of incomplete intake documentation, the FI could not be calculated in 57 (13.5%) patients, but these "unknown frailty" patients were also at increased risk for postoperative pneumonia, 3.15 (1.29-7.72). DISCUSSION: Three commonly used stratification indices (ASA-PS score, CCI, and FI) were associated with increased risk for postoperative pneumonia. Patients unable to complete intake form to calculate the FI were also at increased risk.

Timeline of sepsis bundle component completion and its association with septic shock outcomes.

PURPOSE: To assess the impact of the timeline of sepsis bundle completion with clinical outcomes in septic shock. MATERIALS AND METHODS: We retrospectively studied adult (≥18 years) patients with septic shock from January 1, 2006, through May 31, 2018, who were admitted to the intensive care unit in Mayo Clinic, Rochester. We divided patients into three groups based on the SSC compliant 1) <1h, 2) 1.1 to 3 h, 3) >3 h after the time of septic shock diagnosis. RESULTS: We enrolled 1052 septic shock patients, among 8% were in group 1, 26% in group 2, and the remaining in group 3. Those who completed all bundle components within 3 h had the lowest 28-day mortality (17.5% vs. 31.4%, p < .001) and higher survival at 90 days (HR = 0.67; 95% CI 0.55-0.80; p < .001). Sepsis bundle completion in <1 h had no significant advantage in 28-day mortality (21.5% vs.15.9%, p = .4) or 90-day survival compared with group 2 (HR = 1.08; 95% CI 0.77-1.53; p = .6). CONCLUSIONS: We showed an association between the completion of SSC bundle components within three hours with lower mortality or earlier shock reversal. This relationship was not evident when compared to bundle completion in 1 h vs. within 3 h.

Effect of initial infusion rates of fluid resuscitation on outcomes in patients with septic shock: a historical cohort study.

BACKGROUND: Fluid resuscitation has become the cornerstone of early septic shock management, but the optimal fluid rate is still not well studied. The goal of this investigation is to examine the relationship between fluid resuscitation rate and septic shock resolution. METHOD: We retrospectively studied adult (≥ 18 years) patients with septic shock, defined based on sepsis III definition, from January 1, 2006, through May 31, 2018, in the medical intensive care unit (MICU) of Mayo Clinic Rochester. The fluid resuscitation time was defined as the time required to infuse the initial fluid bolus of 30 ml/kg, based on the recommendations of the 2016 surviving sepsis campaign. The cohort was divided into four groups based on the average fluid rate (group 1 ≥ 0.5, group 2 0.25-0.49, group 3 0.17-0.24, and group 4 < 0.17 ml/kg/min). The primary outcome was the time to shock reversal. Multivariable regression analyses were conducted to account for potential confounders. RESULT: A total of 1052 patients met eligibility criteria and were included in the analysis. The time-to-shock reversal was significantly different among the groups (P < .001). Patients in group 1 who received fluid resuscitation at a faster rate had a shorter time to shock reversal (HR = 0.78; 95% CI 0.66-0.91; P = .01) when compared with group 4 with a median (IQR) time-to-shock reversal of 1.7 (1.5, 2.0) vs. 2.8 (2.6, 3.3) days, respectively. Using 0.25 ml/kg/min as cutoff, the higher fluid infusion rate was associated with a shorter time to shock reversal (HR = 1.22; 95% CI 1.06-1.41; P = .004) and with decreased odds of 28-day mortality (HR = 0.71; 95% CI 0.60-0.85; P < .001). CONCLUSION: In septic shock patients, initial fluid resuscitation rate of 0.25-0.50 ml/kg/min (i.e., completion of the initial 30 ml/kg IV fluid resuscitation within the first 2 h), may be associated with early shock reversal and lower 28-day mortality compared with slower rates of infusion.

Postoperative Nausea and Vomiting and Phase I Post-anesthesia Recovery After Strabismus Operations.

PURPOSE: To ascertain postoperative nausea and vomiting (PONV) rates in adult patients after strabismus operations and assess causes for prolonged post-anesthesia recovery. METHODS: This was a retrospective observational study of consecutive adult patients who underwent strabismus operations at one institution from January 1, 2010, to May 31, 2017. The anesthetic records were abstracted and PONV rates were ascertained. On the basis of the cohort's 75th percentile of anesthesia recovery duration, patients were categorized into goal recovery (lower three quartiles) and prolonged recovery (upper quartile). Multivariable logistic regression analyses were performed to assess associations between clinical characteristics and prolonged recovery. RESULTS: A total of 794 adult patients who underwent strabismus surgery were identified. PONV was present in 31 (3.9%) patients. The median (interquartile range) post-anesthesia recovery was 45 minutes (range: 33 to 63 minutes). Prolonged recovery was associated with long-term benzodiazepine use (odds ratio [OR]: 3.07; 95% CI [confidence interval]: 1.23 to 7.80; P = .02). Patients with prolonged recovery had higher rates of PONV (15 [7.2%] vs 16 [2.7%], P = .007), oversedation (107 [51.4%] vs 226 [38.6%], P = .001), and postoperative analgesic administration (138 [66.4%] vs 222 [37.9%], P < .001). Inverse associations were found between desflurane and oversedation (OR: 0.63; 95% CI: 0.45 to 0.86; P = .004) and between acetaminophen administration and postoperative analgesic administration (OR: 0.57; 95% CI: 0.38 to 0.86; P = .007). CONCLUSIONS: Adult patients undergoing general anesthesia for strabismus surgery had a low PONV rate. However, the presence of PONV was associated with delayed recovery room discharge. Other factors associated with prolonged Phase I recovery were long-term benzodiazepine use and longer operations, which likely resulted in an increased need for anesthetic agents and therefore more intense postoperative sedation. [J Pediatr Ophthalmol Strabismus. 2019;56(3):151-156.].