Anesthesia & Analgesia

Clinical Outcomes of Pregnant and Postpartum Extracorporeal Membrane Oxygenation Patients BACKGROUND: The use of extracorporeal membrane oxygenation (ECMO) as a rescue therapy for cardiopulmonary failure is expanding in critical care medicine. In this case series, we describe the clinical outcomes of 21 consecutive pregnant or postpartum patients that required venovenous (VV) or venoarterial (VA) ECMO. Our objective was to characterize maternal and fetal survival in peripartum ECMO and better understand ECMO-related complications that occur in this unique patient population. METHODS: Between January 2009 and June 2019, all pregnant and postpartum patients treated with ECMO for respiratory or circulatory failure at a single quaternary referral center were identified. For all patients, indications for ECMO, maternal and neonatal outcomes, details of ECMO support, and anticoagulation and bleeding complications were collected. RESULTS: Twenty-one obstetric patients were treated with ECMO over 10 years. Thirteen patients were treated with VV ECMO and 8 patients were treated with VA ECMO. Six patients were pregnant at the time of cannulation and 3 patients delivered while on ECMO; all 6 maternal and infant dyads survived to hospital discharge. The median gestational age at cannulation was 28 weeks (interquartile range [IQR], 24–31). In the postpartum cohort, ECMO initiation ranged from immediately after delivery up to 46 days postpartum. Fifteen women survived (72%). Major bleeding complications requiring surgical intervention were observed in 7 patients (33.3%). Two patients on VV ECMO required bilateral orthotopic lung transplantation and 1 patient on VA ECMO required orthotopic heart transplantation to wean from ECMO. CONCLUSIONS: Survival for mother and neonate are excellent with peripartum ECMO in a high-volume ECMO center. Neonatal and maternal survival was 100% when ECMO was used in the late second or early third trimester. Based on these results, ECMO remains an important treatment option for peripartum patients with cardiopulmonary failure.

Efficiency Metrics at an Academic Freestanding Ambulatory Surgery Center: Analysis of the Impact on Scheduled End-Times BACKGROUND: Understanding the impact of key metrics on operating room (OR) efficiency is important to optimize utilization and reduce costs, particularly in freestanding ambulatory surgery centers. The aim of this study was to assess the association between commonly used efficiency metrics and scheduled end-time accuracy. METHODS: Data from patients who underwent surgery from May 2018 to June 2019 at an academic freestanding ambulatory surgery center was extracted from the medical record. Unique operating room days (ORDs) were analyzed to determine (1) duration of first case delays, (2) turnover times (TOT), and (3) scheduled case duration accuracies. Spearman's correlation coefficients and mixed-effects multivariable linear regression were used to assess the association of each metric with scheduled end-time accuracy. RESULTS: There were 1378 cases performed over 300 unique ORDs. There were 86 (28.7%) ORDs with a first case delay, mean (standard deviation [SD]) 11.2 minutes (15.1 minutes), range of 2–101 minutes; the overall mean (SD) TOT was 28.1 minutes (19.9 minutes), range of 6–83 minutes; there were 640 (46.4%) TOT >20 minutes; the overall mean (SD) case duration accuracy was −6.6 minutes (30.3 minutes), range of −114 to 176; and there were 389 (28.2%) case duration accuracies ≥30 minutes. The mean (SD) scheduled end-time accuracy was 6.9 minutes (68.3 minutes), range of −173 to 229 minutes; 48 (15.9%) ORDs ended ≥1 hour before scheduled end-time and 56 (18.6%) ORDs ended ≥1 hour after scheduled end-time. The total case duration accuracy was strongly correlated with the scheduled end-time accuracy (r = 0.87, 95% confidence interval [CI], 0.84-0.89, P < .0001), while the total first case delay minutes (r = 0.12, 95% CI, 0.01-0.21, P = .04) and total turnover time (r = −0.16, 95% CI, 0.21-0.05, P = .005) were less relevant. Case duration accuracy had the highest association with the dependent variable (0.95 minutes changed in the difference between actual and schedule end time per minute increase in case duration accuracy, 95% CI, 0.90-0.99, P < .0001), compared to turnover time (estimate = 0.87, 95% CI, 0.75-0.99, P < .0001) and first case delay time (estimate = 0.83, 95% CI, 0.56-1.11, P < .0001). CONCLUSIONS: Standard efficiency metrics are similarly associated with scheduled end-time accuracy, and addressing problems in each is requisite to having an efficient ambulatory surgery center. Pursuing methods to narrow the gap between scheduled and actual case duration may result in a more productive enterprise.

Postoperative Morbidity and Mortality in Diabetic Patients After Fast-Track Hip and Knee Arthroplasty: A Prospective Follow-up Cohort of 36,762 Procedures BACKGROUND: Diabetes increases the risk of adverse outcomes in surgical procedures, including total hip and knee arthroplasty (THA/TKA), and the prevalence of diabetic patients undergoing these procedures is high, ranging from approximately 8% to 20%. However, there is still a need to clarify the role of diabetes and antihyperglycemic treatment in a fast-track THA/TKA setting, which otherwise may decrease morbidity. Consequently, we investigated the association between diabetes and antihyperglycemic treatment on length of stay (LOS) and complications following fast-track THA/TKA within a multicenter fast-track collaboration. METHODS: We used an observational study design on data from a prospective multicenter fast-track collaboration on unselected elective primary THA/TKA from 2010 to 2017. Complete follow-up (>99%) was achieved through The Danish National Patient Registry, antihyperglycemic treatment established through the Danish National Database of Reimbursed Prescriptions and types of complications leading to LOS >4 days, 90-day readmission or mortality obtained by scrutinizing health records and discharge summaries. Patients were categorized as nondiabetic and if diabetic into insulin-, orally, and dietary-treated diabetic patients. RESULTS: A total of 36,762 procedures were included, of which 837 (2.3%) had insulin-treated diabetes, 2615 (7.1%) orally treated diabetes, and 566 (1.5%) dietary-treated diabetes. Overall median LOS was 2 (interquartile range [IQR]: 1–3) days, and mean LOS was 2.4 (standard deviation [SD], 2.5) days. The proportion of patients with LOS >4 days was 6.0% for nondiabetic patients, 14.7% for insulin-treated, 9.4% for orally treated, and 9.5% for dietary-treated diabetic patients. Pharmacologically treated diabetes (versus nondiabetes) was independently associated with increased odds of LOS >4 days (insulin-treated: odds ratio [OR], 2.2 [99.6% confidence interval {CI}, 1.3–3.7], P < .001; orally treated: OR, 1.5 [99.6% CI, 1.0-2.1]; P = .002). Insulin-treated diabetes was independently associated with increased odds of "diabetes-related" morbidity (OR, 2.3 [99.6% CI, 1.2-4.2]; P < .001). Diabetic patients had increased renal complications regardless of antihyperglycemic treatment, but only insulin-treated patients suffered significantly more cardiac complications than nondiabetic patients. There was no increase in periprosthetic joint infections or mortality associated with diabetes. CONCLUSIONS: Patients with pharmacologically treated diabetes undergoing fast-track THA/TKA were at increased odds of LOS >4 days. Although complication rates were low, patients with insulin-treated diabetes were at increased odds of postoperative complications compared to nondiabetic patients and to their orally treated counterparts. Further investigation into the pathogenesis of postoperative complications differentiated by antihyperglycemic treatment is needed.

Intermittent Hypoxia and Effects on Early Learning/Memory: Exploring the Hippocampal Cellular Effects of Pediatric Obstructive Sleep Apnea This review provides an update on the neurocognitive phenotype of pediatric obstructive sleep apnea (OSA). Pediatric OSA is associated with neurocognitive deficits involving memory, learning, and executive functioning. Adenotonsillectomy (AT) is presently accepted as the first-line surgical treatment for pediatric OSA, but the executive function deficits do not resolve postsurgery, and the timeline for recovery remains unknown. This finding suggests that pediatric OSA potentially causes irreversible damage to multiple areas of the brain. The focus of this review is the hippocampus, 1 of the 2 major sites of postnatal neurogenesis, where new neurons are formed and integrated into existing circuitry and the mammalian center of learning/memory functions. Here, we review the clinical phenotype of pediatric OSA, and then discuss existing studies of OSA on different cell types in the hippocampus during critical periods of development. This will set the stage for future study using preclinical models to understand the pathogenesis of persistent neurocognitive dysfunction in pediatric OSA.

Development and Evaluation of a Risk-Adjusted Measure of Intraoperative Hypotension in Patients Having Nonemergent, Noncardiac Surgery BACKGROUND: Intraoperative hypotension is common and associated with organ injury and death, although randomized data showing a causal relationship remain sparse. A risk-adjusted measure of intraoperative hypotension may therefore contribute to quality improvement efforts. METHODS: The measure we developed defines hypotension as a mean arterial pressure <65 mm Hg sustained for at least 15 cumulative minutes. Comparisons are based on whether clinicians have more or fewer cases of hypotension than expected over 12 months, given their patient mix. The measure was developed and evaluated with data from 225,389 surgeries in 5 hospitals. We assessed discrimination and calibration of the risk adjustment model, then calculated the distribution of clinician-level measure scores, and finally estimated the signal-to-noise reliability and predictive validity of the measure. RESULTS: The risk adjustment model showed acceptable calibration and discrimination (area under the curve was 0.72 and 0.73 in different validation samples). Clinician-level, risk-adjusted scores varied widely, and 36% of clinicians had significantly more cases of intraoperative hypotension than predicted. Clinician-level score distributions differed across hospitals, indicating substantial hospital-level variation. The mean signal-to-noise reliability estimate was 0.87 among all clinicians and 0.94 among clinicians with >30 cases during the 12-month measurement period. Kidney injury and in-hospital mortality were most common in patients whose anesthesia providers had worse scores. However, a sensitivity analysis in 1 hospital showed that score distributions differed markedly between anesthesiology fellows and attending anesthesiologists or certified registered nurse anesthetists; score distributions also varied as a function of the fraction of cases that were inpatients. CONCLUSIONS: Intraoperative hypotension was common and was associated with acute kidney injury and in-hospital mortality. There were substantial variations in clinician-level scores, and the measure score distribution suggests that there may be opportunity to reduce hypotension which may improve patient safety and outcomes. However, sensitivity analyses suggest that some portion of the variation results from limitations of risk adjustment. Future versions of the measure should risk adjust for important patient and procedural factors including comorbidities and surgical complexity, although this will require more consistent structured data capture in anesthesia information management systems. Including structured data on additional risk factors may improve hypotension risk prediction which is integral to the measure's validity.

Do Elderly Patients With Diastolic Dysfunction Require Higher Doses of Norepinephrine During General Anesthesia for Noncardiac Surgeries? A Prospective Observational Study BACKGROUND: Diastolic dysfunction is a risk factor for postoperative major cardiovascular events. During anesthesia, patients with diastolic dysfunction might experience impaired hemodynamic function and worsening of diastolic function, which in turn, might be associated with a higher incidence of postoperative complications. We aimed to investigate whether patients with diastolic dysfunction require higher doses of norepinephrine during general anesthesia. Furthermore, we aimed to examine the association between the grade of diastolic dysfunction and the E/e' ratio during anesthesia. A high E/e' ratio corresponds to elevated filling pressures and is an important measure of impaired diastolic function. METHODS: We conducted a prospective observational cohort study at a German university hospital from February 2017 to September 2018. Patients aged ≥60 years and undergoing general anesthesia (ie, propofol and sevoflurane) for elective noncardiac surgery were enrolled. Exclusion: mitral valve disease, atrial fibrillation, and implanted mechanical device. The primary outcome parameter was the administered dose of norepinephrine within 30 minutes after anesthesia induction (μg·kg−1 30 min−1). The secondary outcome parameter was the change of Doppler echocardiographic E/e' from ECHO1 (baseline) to ECHO2 (anesthesia). Linear models and linear mixed models were used for statistical evaluation. RESULTS: A total of 247 patients were enrolled, and 200 patients (75 female) were included in the final analysis. Diastolic dysfunction at baseline was not associated with a higher dose of norepinephrine during anesthesia (P = .6953). The grade of diastolic dysfunction at baseline was associated with a decrease of the E/e' ratio during anesthesia (P < .001). CONCLUSIONS: We did not find evidence for an association between diastolic dysfunction and impaired hemodynamic function, as expressed by high vasopressor support during anesthesia. Additionally, our findings suggest that diastolic function, as expressed by the E/e' ratio, does not worsen during anesthesia.

Fiber-Needle Swept-Source Optical Coherence Tomography for the Real-Time Visualization of the Transversus Abdominis Plane Block Procedure in a Swine Model BACKGROUND: Fascia blocks (eg, the transversus abdominis plane [TAP] block) target the intermuscular fascia layers. Ultrasound techniques have allowed peripheral blocks to be performed with accuracy and safety, however, with limitations. Optical coherence tomography (OCT) is based on low-coherence interferometry. In this study, we examined the ability of OCT to identify the TAP. METHODS: A swept-source OCT probe was placed in a 17-gauge needle to obtain imaging. The needle was inserted within 2 different angle ranges (0°–30° and 30°–60°) on a slice of pork belly to assess imaging characteristics. A series of real-time OCT imaging of the muscle, fascia, and interfascial space was obtained. The tissue location of the needle tip was identified using near-infrared (NIR) imaging. In vivo OCT imaging was further done on 3 female 6-month-old native Chinese Landrance Duroc pigs. Real-time images of tissue layers were obtained with needle insertion. Ultrasound imaging of the OCT needle probe was also performed at the same time for needle trajectory guidance. After imaging, the OCT probe was removed, and 5 mL of normal saline was injected via the needle to confirm correct fascia plane identification. RESULTS: In and ex vivo studies showed clear visual distinction of muscle, fascia, and interfascial layer with OCT, with limitations. Independent validation of OCT criteria for the muscle/fascia differentiation by 20 OCT readers for the in vivo data demonstrated the sensitivity = 0.91, specificity = 0.90, and accuracy = 0.89. Although the angle of needle entry affected the depth of OCT penetration in the muscle, the attenuation coefficient values of the fascia and muscle tissue were statistically different (P < .001) and with high area under the receiver operating characteristics (ROC) curve (AUC) (AUC = 0.93 in 0°–30° and AUC = 1 in 30°–60°) for fascia identification. CONCLUSIONS: This study introduced a novel needle imaging probe method to identify the transversus abdominis fascia plane in real-time. Quantitative calculation of the attenuation coefficients can further aid objective identification by providing direct confirmation of the tip position, increasing the first-pass success rate, and decreasing the need for needle repositioning. Combining OCT and ultrasound may improve the accuracy of anesthetics placement.

Incidence, Mortality, and Characteristics of 18 Pediatric Perioperative Cardiac Arrests: An Observational Trial From 22,650 Pediatric Anesthesias in a German Tertiary Care Hospital BACKGROUND: Recently, a very low incidence of 3 per 10,000 and a mortality of 30% were reported for pediatric perioperative cardiac arrest (POCA). However, high-risk patients, namely children already anesthetized on the intensive care unit (ICU), were excluded. This study investigates the incidence and mortality of POCA in children in whom anesthesia was induced in the ICU or in the operating room using real-world data. In addition, different classifications of POCA were compared with respect to outcome relevance. METHODS: This is a retrospective observational study conducted at a German level 1 perinatal center and tertiary care hospital between 2008 and 2018. Children ≤15 years who underwent an anesthetic procedure and suffered from POCA (defined as any condition requiring chest compressions and/or defibrillation) from the beginning of care provided by an anesthesiologist to 60 minutes after anesthesia or sedation were included. Primary end points were incidence and mortality of POCA in children with anesthesia induced in the ICU versus in the operating room. Secondary end points included incidences and outcomes with respect to the pathophysiological cause (respiratory versus circulatory associated). RESULTS: There were 18 POCA during 22,650 anesthetic procedures (incidence 7.9 per 10,000; 95% confidence interval [CI], 4.7-12.5). Thirty-day mortality was 3.5 per 10,000 (95% CI, 1.5-6.9). Incidence and mortality were higher in children in whom anesthesia was induced in the ICU versus in the operating room (incidence: 131.6; 95% CI, 57 to 257.6 versus 4.5; 95% CI, 2.2-8.3; P < .001; and mortality: 82.2; 95% CI, 26.7-190.8 versus 1.4; 95% CI, 0.3-3.9; P < .001). Mortality in circulatory-induced POCA (n = 8; 44%) was 100%, in respiratory-induced POCA (n = 9; 50%) 0% (P < .001). CONCLUSIONS: Children with anesthesia induction in the ICU represent a high-risk population for POCA and POCA-associated mortality. POCA classification should be based on the individual cause (respiratory versus circulatory) rather than on the perioperative phase or the responsible specialty.

A Bayesian Comparison of Frailty Instruments in Noncardiac Surgery: A Cohort Study BACKGROUND: Frailty—a multidimensional syndrome related to age- and disease-related deficits—is a key risk factor for older surgical patients. However, it is unknown which frailty instrument most accurately predicts postoperative outcomes. Our objectives were to quantify the probability of association and relative predictive performance of 2 frailty instruments (ie, the risk analysis index-administrative [RAI-A] and 5-item modified frailty index [mFI-5]) with postoperative outcomes in National Surgical Quality Improvement Program (NSQIP) data. METHODS: Retrospective cohort study using Bayesian analysis of NSQIP hospitals. Adults having inpatient small or large bowel surgery 2010–2015 (derivation cohort) or intermediate to high risk mixed noncardiac surgery in 2016 (validation cohort) had preoperative frailty assigned using 2 unique approaches (RAI-A and mFI-5). Probabilities of association were calculated based on posterior distributions and relative predictive performance using posterior predictive distributions and Bayes factors for 30-day mortality (primary outcome) and serious complications (secondary outcome). RESULTS: Of 50,630 participants, 7630 (14.0%) died and 19,545 (38.6%) had a serious complication. Without adjustment, the RAI-A and mFI-5 had >99% probability being associated with mortality with a ≥2.0 odds ratio (ie, large effect size). After adjustment for NSQIP risk calculator variables, only the RAI-A had ≥95% probability of a nonzero association with mortality. Similar results arose when predicting postoperative complications. The RAI-A provided better predictive accuracy for mortality than the mFI-5 (minimum Bayes factor 3.25 × 1014), and only the RAI-A improved predictive accuracy beyond that of the NSQIP risk calculator (minimum Bayes factor = 4.27 × 1013). Results were consistent in leave-one-out cross-validation. CONCLUSIONS: Translation of frailty-related findings from research and quality improvement studies to clinical care and surgical planning will be aided by a consistent approach to measuring frailty with a multidimensional instrument like RAI-A, which appears to be superior to the mFI-5 when predicting outcomes for inpatient noncardiac surgery.

Assessment of Anesthesia Capacity in Public Surgical Hospitals in Guatemala BACKGROUND: International standards for safe anesthetic care have been developed by the World Federation of Societies of Anaesthesiologists (WFSA) and the World Health Organization (WHO). Whether these standards are met is unknown in many nations, including Guatemala, a country with universal health coverage. We aimed to establish an overview of anesthesia care capacity in public surgical hospitals in Guatemala to help guide public sector health care development. METHODS: In partnership with the Guatemalan Ministry of Public Health and Social Assistance (MSPAS), a national survey of all public hospitals providing surgical care was conducted using the WFSA anesthesia facility assessment tool (AFAT) in 2018. Each facility was assessed for infrastructure, service delivery, workforce, medications, equipment, and monitoring practices. Descriptive statistics were calculated and presented. RESULTS: Of the 46 public hospitals in Guatemala in 2018, 36 (78%) were found to provide surgical care, including 20 district, 14 regional, and 2 national referral hospitals. We identified 573 full-time physician surgeons, anesthesiologists, and obstetricians (SAO) in the public sector, with an estimated SAO density of 3.3/100,000 population. There were 300 full-time anesthesia providers working at public hospitals. Physician anesthesiologists made up 47% of these providers, with an estimated physician anesthesiologist density of 0.8/100,000 population. Only 10% of district hospitals reported having an anesthesia provider continuously present intraoperatively during general or neuraxial anesthesia cases. No hospitals reported assessing pain in the immediate postoperative period. While the availability of some medications such as benzodiazepines and local anesthetics was robust (100% availability across all hospitals), not all hospitals had essential medications such as ketamine, epinephrine, or atropine. There were deficiencies in the availability of essential equipment and basic intraoperative monitors, such as end-tidal carbon dioxide detectors (17% availability across all hospitals). Postoperative care and access to resuscitative equipment, such as defibrillators, were also lacking. CONCLUSIONS: This first countrywide, MSPAS-led assessment of anesthesia capacity at public facilities in Guatemala revealed a lack of essential materials and personnel to provide safe anesthesia and surgery. Hospitals surveyed often did not have resources regardless of hospital size or level, which may suggest multiple factors preventing availability and use. Local and national policy initiatives are needed to address these deficiencies.

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Medicine by Alexandros G. Sfakianakis,Anapafseos 5 Agios Nikolaos 72100 Crete Greece,00302841026182,00306932607174,alsfakia@gmail.com,

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