Jacob, Adam K.

BACKGROUND: Preoperative anemia is common and associated with adverse outcomes in surgical patients. There is limited information to guide the design and implementation of preoperative anemia clinics (PAC), which represents a critical barrier to entry for many practices. METHODS: This is a descriptive observational study highlighting the design and implementation of a multidisciplinary PAC, including key steps in planning, stakeholder engagement, organizational structure, identification of target populations, establishing anemia treatments, information technology and electronic health record integration, provider training, and data infrastructure. Demographic and clinical characteristics, laboratory results, and anemia treatments for individuals evaluated in the PAC from November 4, 2019 through September 15, 2023 are enumerated. Patient-reported outcomes (PROs) assessing changes in anemia symptoms and well-being after surgery are evaluated for 2 subsets of patients (one before PAC implementation [pre-PAC], another after PAC implementation [post-PAC]), without formal statistical comparison given limited sample sizes. RESULTS: The PAC was initiated as a multidisciplinary effort under support from a Mayo Clinic Practice Transformation Award in 2019, including broad representation from anesthesiology, surgery, and medical practices, along with institutional project management support (eg, project manager, information technologists, systems engineers). While initially limited to cardiac surgery patients, the PAC underwent planned incremental expansion to include other surgical services. Over the study period, 1188 PAC consultations across 1159 unique patients met eligibility criteria, with a median age of 66 (57–73) years and 58.1% women. The most common etiology of anemia was iron deficiency (69.1%) followed by anemia related to cancer (17.3%). Anemia-directed therapies were recommended in 1038 (87.4%) encounters, with 730 (70.3%) of those receiving recommended treatment preoperatively. Seven hundred nine (97.1%) treatments included intravenous iron and 146 (20.0%) included erythropoiesis-stimulating agents. Fifteen pre-PAC and 38 post-PAC implementation patients completed PROs. PAC implementation was accompanied by earlier resolution of anemia symptoms and less pronounced declines in postoperative well-being scores. CONCLUSIONS: This report highlights the key steps for successful PAC implementation. Treatment is possible for most patients and may be accompanied by improvements in patient-important outcomes.

Abstract Background Existing clinical preoperative risk assessment tools such as the Revised Cardiac Risk Index (RCRI) have been used extensively to predict perioperative major adverse cardiovascular events (MACE). Electrocardiogram (ECG) analysis using Deep Learning can identify hidden features that human eyes cannot identify and might help further risk stratify patients undergoing noncardiac surgery. Objective We aimed to develop a Deep Learning model that predicts perioperative MACE in patients undergoing elective noncardiac surgeries. Methods We included patients ≥ 18-year-old who underwent elective non-cardiac surgery between 2000-2021. MACE was validated in duplicate and were defined as a composite of in-hospital myocardial infarction, cardiac arrest or mortality. A convolutional neural network was developed using ECGs within 30 days before surgery. We randomly split subjects into training, internal validation, and testing datasets in a 7:1:2 ratio. Performance was evaluated using the area under the receiver operator characteristics curve (AUC) values on the testing dataset. Models trained included AI-ECG models to predict in-hospital MACE and to predict in-hospital mortality, and AI-ECG+RCRI models to predict in-hospital MACE and to predict in-hospital mortality. All models were validated using 30-day validated outcomes (MACE or all-cause mortality) in a community-based cohort and were compared with the Revised Cardiac Risk Index (RCRI) score using AUC values. Findings: We included 195,214 patients who underwent a total of 241,999 surgeries. 169,214 ECGs were used in the training dataset, 24,234 in the internal validation dataset, and 48,551 in the testing dataset. In the test cohort, the AI-ECG algorithm discriminated risk for in-hospital MACE with an AUC of 0.82 (95% CI 0.79-0.85). The algorithm similarly discriminated 30-day MACE with an AUC value of 0.79 (95% CI 0.77-0.81) surpassing the discrimination of the RCRI score AUC of 0.69 (95% CI 0.66-0.72). All models’ performances are shown in Figure1A. The AI-ECG model to predict in-hospital mortality had an AUC of 0.83 (95% CI 0.80-0.86) and predicted 30-day mortality with an AUC of 0.80 (95% CI 0.77-0.82). Other models’ performances are shown Figure1B. Training the AI-ECG models including RCRI data did not improve the AI-ECG models’ performance. Conclusion AI-ECG models with no additional clinical data can improve perioperative risk prediction in non-cardiac surgery, outperforming a conventional and widely used risk stratification tool such as the RCRI.

AbstractBackgroundPreoperative 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 MethodsThis 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%.ResultsA 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).ConclusionThe use of SpHb devices for anemia screening in surgical patients is feasible with the potential to reliably rule‐out anemia despite limited accuracy.

Background. Dexmedetomidine is a selective α-2 agonist commonly used for sedation that has been used in obstetric anesthesia for multimodal labor analgesia, postcesarean delivery analgesia, and perioperative shivering. This study evaluated the role of intravenous dexmedetomidine to provide rescue analgesia and/or sedation during cesarean delivery under neuraxial anesthesia. Methods. We conducted a single-center, retrospective cohort study of all parturients undergoing cesarean delivery under neuraxial anesthesia between December 1, 2018, and November 30, 2019, who required supplemental analgesia during the procedure. Patients were divided into two groups: patients who received intravenous dexmedetomidine (Dexmed group) and patients who received adjunct medications such as fentanyl, midazolam, ketamine, and nitrous oxide (Standard group). Primary outcome was incidence of conversion to general anesthesia. Results. During the study period, 107 patients received adjunct medications. There was no difference in conversion to general anesthesia between the Dexmed group and the Standard group (6% (4/62) vs. 9% (4/45); p = 0.718 ). In the Dexmed group, the mean dexmedetomidine dose received was 37 μg (range 10 to 140 μg). While the use of inotropic/vasopressor medications was common and similar in both groups, there was an increase in the incidence of bradycardia (Dexmed 15% vs. Standard 2%; p = 0.042 ) but not hypotension (Dexmed 24% vs. Standard 24%; p = 1.00 ) in the Dexmed group. Conclusion. In patients who required supplemental analgesia for cesarean delivery, those who received dexmedetomidine versus other medications had a similar rate of conversion to general anesthesia, a statistically significant increase in bradycardia, but no difference in the incidence of hypotension.

Abstract Hereditary angioedema (HAE) is a disease manifested by repeated episodes of localized submucosal or subcutaneous edematous episodes, potentially triggered by emotional stress, mechanical trauma, or intake of estrogens. We present our experience managing two parturients with HAE. Multidisciplinary care is essential for planning and executing the specialized care of these patients, and management included extensive planning among obstetric, anesthesiology, and allergy and immunology teams. Pregnancy has been shown to have a variable effect on triggering HAE episodes. First-line treatment includes C1 esterase inhibitor concentrate, which can also be used for prophylaxis in high-risk patients. Neuraxial analgesia is recommended to avoid general anesthesia and was established early in both individuals. Vaginal delivery was well tolerated without need for emergent treatment for angioedema symptoms.

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.

Abstract Background Intrathecal opioids are routinely administered during spinal anesthesia for postcesarean analgesia. The effectiveness of intrathecal morphine for postcesarean analgesia is well established, and the use of intrathecal hydromorphone is growing. No prospective studies have compared the effectiveness of equipotent doses of intrathecal morphine versus intrathecal hydromorphone as part of a multimodal analgesic regimen for postcesarean analgesia. The authors hypothesized that intrathecal morphine would result in superior analgesia compared with intrathecal hydromorphone 24 h after delivery. Methods In this single-center, double-blinded, randomized trial, 138 parturients undergoing scheduled cesarean delivery were randomized to receive 150 µg of intrathecal morphine or 75 µg of intrathecal hydromorphone as part of a primary spinal anesthetic and multimodal analgesic regimen; 134 parturients were included in the analysis. The primary outcome was the numerical rating scale score for pain with movement 24 h after delivery. Static and dynamic pain scores, nausea, pruritus, degree of sedation, and patient satisfaction were assessed every 6 h for 36 h postpartum. Total opioid consumption was recorded. Results There was no significant difference in pain scores with movement at 24 h (intrathecal hydromorphone median [25th, 75th] 4 [3, 5] and intrathecal morphine 3 [2, 4.5]) or at any time point (estimated difference, 0.5; 95% CI, 0 to 1; P = 0.139). Opioid received in the first 24 h did not differ between groups (median [25th, 75th] oral morphine milligram equivalents for intrathecal hydromorphone 30 [7.5, 45.06] vs. intrathecal morphine 22.5 [14.0, 37.5], P = 0.769). From Kaplan–Meier analysis, the median time to first opioid request was 5.4 h for hydromorphone and 12.1 h for morphine (log-rank test P = 0.200). Conclusions Although the hypothesis was that intrathecal morphine would provide superior analgesia to intrathecal hydromorphone, the results did not confirm this. At the doses studied, both intrathecal morphine and intrathecal hydromorphone provide effective postcesarean analgesia when combined with a multimodal analgesia regimen. Editor’s Perspective What We Already Know about This Topic What This Article Tells Us That Is New

Abstract Background Transverse abdominis plane (TAP) block is considered an effective alternative to neuraxial analgesia for abdominal surgery. However, limited evidence supports its use over traditional analgesic modalities in colorectal surgery. This study compared the analgesic efficacy of liposomal bupivacaine TAP block with intrathecal (IT) opioid administration in a multicentre RCT. Methods Patients undergoing elective small bowel or colorectal resection were randomized to receive TAP block or a single injection of IT analgesia with hydromorphone. Patients were assessed at 4, 8, 16, 24 and 48 h after surgery. Primary outcomes were mean pain scores and morphine milligram equivalents (MMEs) administered within 48 h after surgery. Secondary outcomes included duration of hospital stay, incidence of postoperative ileus and use of intravenous patient-controlled analgesia. Results In total, 209 patients were recruited and 200 completed the trial (TAP 102, IT 98). The TAP group had a 1·6-point greater mean pain score than the IT group at 4 h after surgery, and this difference lasted for 16 h after operation. The TAP group received more MMEs within the first 24 h after surgery than the IT group (median difference in MMEs 10·0, 95 per cent c.i. 3·0 to 20·5). There were no differences in MME use at 24 and 48 h, or with respect to secondary outcomes. Conclusion IT opioid administration provided better immediate postoperative pain control than TAP block. Both modalities resulted in low pain scores in patients undergoing elective colorectal surgery and should be considered in multimodal postoperative analgesic plans. Registration number: NCT02356198 ( http://www.clinicaltrials.gov).

Objectives Local anesthetic injection into the interspace between the popliteal artery and the posterior capsule of the knee (IPACK) has the potential to provide motor‐sparing analgesia to the posterior knee after total knee arthroplasty. The primary objective of this cadaveric study was to evaluate injectate spread to relevant anatomic structures with IPACK injection. Methods After receipt of Institutional Review Board Biospecimen Subcommittee approval, IPACK injection was performed on fresh‐frozen cadavers. The popliteal fossa in each specimen was dissected and examined for injectate spread. Results Ten fresh‐frozen cadaver knees were included in the study. Injectate was observed to spread in the popliteal fossa at a mean ± SD of 6.1 ± 0.7 cm in the medial‐lateral dimension and 10.1 ± 3.2 cm in the proximal‐distal dimension. No injectate was noted to be in contact with the proximal segment of the sciatic nerve, but 3 specimens showed injectate spread to the tibial nerve. In 3 specimens, the injectate showed possible contact with the common peroneal nerve. The middle genicular artery was consistently surrounded by injectate. Conclusions This cadaver study of IPACK injection demonstrated spread throughout the popliteal fossa without proximal sciatic involvement. However, the potential for injectate to spread to the tibial or common peroneal nerve was demonstrated. Consistent surrounding of the middle genicular artery with injectate suggests a potential mechanism of analgesia for the IPACK block, due to the predictable relationship between articular sensory nerves and this artery. Further study is needed to determine the ideal site of IPACK injection.