Anesthesia & Analgesia

Factors Associated With Failure of Spinal Anesthetic: An 8-Year Retrospective Analysis of Patients Undergoing Elective Hip and Knee Joint Arthroplasty The primary outcome of this 8-year retrospective review was the failure of spinal anesthetic (SA) in elective hip and knee joint arthroplasty surgery. Of 3542 SAs, a total of 135 failures were identified (3.8%). Factors associated with increased odds of failure were younger age (odds ratio [OR], 1.03; 95% confidence interval [CI], 1.01–1.05), lower body mass index (BMI; OR, 1.04 [1.01–1.08]), hip arthroplasty (OR, 1.90 [1.28–2.84]) compared to knee arthroplasty, needle insertion at L4-5 (OR, 4.61 [2.02–10.54]) and L5-S1 (OR, 7.66 [2.47–23.7]) compared to L2-3, 22-gauge needle size (OR, 2.17 [1.34–3.52]) compared to 25-gauge needle, and hyperbaric bupivacaine (OR, 1.66 [1.09–2.53]) compared to isobaric bupivacaine. Accepted for publication May 20, 2019. Funding: This project received a $2000 support from the Department of Anesthesia, Perioperative Medicine and Pain Management, Dalhousie University, Nova Scotia Health Authority, for statistical consultation. Conflicts of Interest: See Disclosures at the end of the article. Supplemental digital content is available for this article. Direct URL citations appear in the printed text and are provided in the HTML and PDF versions of this article on the journal’s website (www.anesthesia-analgesia.org). Reprints will not be available from the authors. Address correspondence to Vishal Uppal, FRCA, Department of Anaesthesia, Pain Management and Perioperative Medicine, Dalhousie University, Halifax Infirmary Site, Room 5452, 1796 Summer St, Halifax, NS B3H 3A6, Canada. Address e-mail to v.uppal@dal.ca. © 2019 International Anesthesia Research Society

Postoperative Respiratory Depression May Be Related to Undiagnosed Sleep-Disordered Breathing or Obstructive Sleep Apnea No abstract available

Viscoelastic Signals for Optimal Resuscitation in Trauma: Kaolin Thrombelastography Cutoffs for Diagnosing Hypofibrinogenemia (VISOR Study) BACKGROUND: Acute traumatic coagulopathy is common in trauma patients. Prompt diagnosis of hypofibrinogenemia allows for early treatment with cryoprecipitate or fibrinogen concentrate. At present, optimal cutoffs for diagnosing hypofibrinogenemia with kaolin thrombelastography (TEG) have not been established. We hypothesized that kaolin kaolin-TEG parameters, such as kinetic time (K-time), α-angle, and maximum amplitude (MA), would accurately diagnose hypofibrinogenemia (fibrinogen <200 mg/dL) and severe hypofibrinogenemia (fibrinogen <100 mg/dL). METHODS: Adult trauma patients (injury severity score >15) presenting to our trauma center between October 2015 and October 2017 were identified retrospectively. All patients had a traditional plasma fibrinogen measurement and kaolin-TEG performed within 15 minutes of each other and within 1 hour of admission. Some patients had additional measurements after. Receiver operating characteristic (ROC) curve analysis was performed to evaluate whether K-time, α-angle, and MA could diagnose hypofibrinogenemia and severe hypofibrinogenemia. Area under the ROC curve (AUROC) was calculated for each TEG parameter with a bootstrapped 99% confidence interval (CI). Further, ROC analysis was used to estimate ideal cutoffs for diagnosing hypofibrinogenemia and severe hypofibrinogenemia by maximizing sensitivity and specificity. In addition, likelihood ratios were also calculated for different TEG variable cutoffs to diagnose hypofibrinogenemia and severe hypofibrinogenemia. RESULTS: Seven hundred twenty-two pairs of TEGs and traditional plasma fibrinogen measurements were performed in 623 patients with 99 patients having additional pairs of tests after the first hour. MA (AUROC = 0.84) and K-time (AUROC = 0.83) better diagnosed hypofibrinogenemia than α-angle (AUROC = 0.8; P = .03 and P < .001 for AUROC comparisons, respectively). AUROCs statistically improved for each parameter when severe hypofibrinogenemia was modeled as the outcome (P < .001). No differences were found between parameters for diagnosing severe hypofibrinogenemia (P > .05 for all comparisons). The estimated optimal cutoffs for diagnosing hypofibrinogenemia were 1.5 minutes for K-time (95% CI, 1.4–1.6), 70.0° for α-angle (95% CI, 69.8–71.0), and 60.9 mm for MA (95% CI, 59.2–61.8). The estimated optimal cutoffs for diagnosing severe hypofibrinogenemia were 2.4 minutes for K-time (95% CI, 1.7–2.8), 60.6° for α-angle (95% CI, 57.2–67.3), and 51.2 mm for MA (95% CI, 49.0–56.2). Currently recommended K-time and α-angle cutoffs from the American College of Surgeons had low sensitivity for diagnosing hypofibrinogenemia (3%–29%), but sensitivity improved to 74% when using optimal cutoffs. CONCLUSIONS: Kaolin-TEG parameters can accurately diagnose hypofibrinogenemia and severe hypofibrinogenemia in trauma patients. Currently recommended cutoffs for the treatment of hypofibrinogenemia are skewed toward high specificity and low sensitivity. Many patients are likely to be undertreated for hypofibrinogenemia using current national guidelines. Accepted for publication May 25, 2019. Funding: None. Conflicts of Interest: See Disclosures at the end of the article. This report describes a cohort observational clinical study. The authors state that the report includes every item in the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) checklist for cohort studies. Reprints will not be available from the authors. Address correspondence to Jonathan H. Chow, MD, Department of Anesthesiology, Division of Critical Care, University of Maryland School of Medicine, 22 S Greene St, S11D20 Baltimore, MD 21201. Address e-mail to jchow@som.umaryland.edu. © 2019 International Anesthesia Research Society

Aviation-Style Computerized Surgical Safety Checklist Displayed on a Large Screen and Operated by the Anesthesia Provider Improves Checklist Performance BACKGROUND: Many hospitals have implemented surgical safety checklists based on the World Health Organization surgical safety checklist, which was associated with improved outcomes. However, the execution of the checklists is frequently incomplete. We reasoned that aviation-style computerized checklist displayed onto large, centrally located screen and operated by the anesthesia provider would improve the performance of surgical safety checklist. METHODS: We performed a prospective before and after observational study to evaluate the effect of a computerized surgical safety checklist system on checklist performance. We created checklist software and translated our 4-part surgical safety checklist from wall poster into an aviation-style computerized format displayed onto a large, centrally located screen and operated by the anesthesia provider. Direct observers recorded performance of the first part of the surgical safety checklist that was initiated before anesthetic induction, including completion of each checklist item, provider participation and distraction level, resistance to use of the checklist, and the time required for checklist completion before and after checklist system implementation. We compared trends of the proportions of cases with 100% surgical safety checklist completion over time between pre- and postintervention periods and assessed for a jump at the start of intervention using segmented logistic regression model while controlling for potential confounding variables. RESULTS: A total of 671 cases were observed before and 547 cases were observed after implementation of the computerized surgical safety checklist system. The proportion of cases in which all of the items of the surgical safety checklist were completed significantly increased from 2.1% to 86.3% after the computerized checklist system implementation (P < .001). Before computerized checklist system implementation, 488 of 671 (72.7%) cases had <75% of checklist items completed, whereas after a computerized checklist system implementation, only 3 of 547 (0.5%) cases had <75% of checklist items completed. CONCLUSIONS: The implementation of a computerized surgical safety checklist system resulted in an improvement in checklist performance. Accepted for publication June 5, 2019. Funding: This study was supported by a grant from Anesthesia Patient Safety Foundation. Conflicts of Interest: See Disclosures at the end of the article. Supplemental digital content is available for this article. Direct URL citations appear in the printed text and are provided in the HTML and PDF versions of this article on the journal’s website (www.anesthesia-analgesia.org). This work was performed at the Department of Anesthesiology and Pain Medicine, University of Washington, Seattle, WA. Reprints will not be available from the authors. Address correspondence to Srdjan Jelacic, MD, FASE, Department of Anesthesiology and Pain Medicine, University of Washington, 1959 NE Pacific St, AA-117B, Box 356540, Seattle, WA 98195. Address e-mail to sjelacic@uw.edu. © 2019 International Anesthesia Research Society

Continuous Noninvasive Hemoglobin Monitoring Reflects the Development of Acute Hemodilution After Consecutive Fluid Challenges BACKGROUND: Consecutive fluid challenges (FCs) are frequently administered to maximize the stroke volume (SV) as part of a goal-directed therapy (GDT) strategy. However, fluid administration may also cause acute hemodilution that might lead to an actual paradoxical decrease in oxygen delivery (DO2). The aim of this study was to examine whether continuous noninvasive hemoglobin (SpHb) monitoring can be used to detect the development of acute hemodilution after graded fluid administration. METHODS: In 40 patients who underwent major vascular or gastrointestinal surgery, an FC, consisting of 250 mL colloid solution, was administered. When the SV increased by ≥10%, the FC was repeated up to a maximum of 3 times. Laboratory-measured hemoglobin concentrations (BHb), SpHb, SV, cardiac output (CO), and DO2 values were recorded after each FC. RESULTS: All 40 patients received the first FC, 32 patients received the second FC, and 20 patients received the third FC (total of 750 mL). Out of the 92 administered FCs, only 55 (60%) caused an increase in SV ≥10% (“responders”). The first and the second FCs were associated with a significant increase in the mean CO and DO2, while the mean SpHb and BHb decreased significantly. However, the third and last FC was associated with no statistical difference in CO and SV, a further significant decrease in mean SpHb and BHb, and a significant decrease in DO2 in these patients. Compared to their baseline values (T0), BHb and SpHb decreased by a mean of 5.3% ± 4.9% and 4.4% ± 5.2%, respectively, after the first FC (T1; n = 40), by 9.7% ± 8.4% and 7.9% ± 6.9% after the second FC (T2; n = 32), and by 14.5% ± 6.2% and 14.6% ± 5.7% after the third FC (T3; n = 20). Concordance rates between the changes in SpHb and in BHb after the administration of 250, 500, and 750 mL colloids were 83%, 90%, and 100%, respectively. CONCLUSIONS: Fluid loading aimed at increasing the SV and the DO2 as part of GDT strategy is associated with acute significant decreases in both BHb and SpHb concentrations. When the administration of an FC is not followed by a significant increase (≥10%) in the SV, the DO2 decreases significantly due to the development of acute hemodilution. Continuous noninvasive monitoring of SpHb does not reflect accurately absolute BHb values, but may be reliably used to detect the development of acute hemodilution especially after the administration of at least 500 mL of colloids. Accepted for publication May 30, 2019. Funding: None. Conflicts of Interest: See Disclosures at the end of the article. Institutional review board: The study was approved by the local institutional ethics committee (Nr. 19630/20.09.2016). Dr Iulia Daniela Kulscar, MD, Secretary of the Ethics Committee. Tel: 0040722729948; Fax: 0040213175221; e-mail: iulia_kulcsar@yahoo.com. Reprints will not be available from the authors. Address correspondence to Şerban Ion Bubenek-Turconi, MD, 1st Department of Cardiovascular Anesthesiology and Intensive Care, Carol Davila University of Medicine and Pharmacy, Bucharest 050474, Romania. Address e-mail to bubenek@alsys.ro. © 2019 International Anesthesia Research Society

Co-existing Diseases and Neuroanesthesia No abstract available

Neuroanesthesia: A Problem-Based Learning Approach, 1st ed No abstract available

Gene Variants in Hepatic Metabolism, Gamma-Aminobutyric Acid-ergic Reward, and Prostaglandin Pathways in Opioid-Consuming and Opioid-Naïve Patients Presenting for Lower Extremity Total Joint Replacement Gene variants may contribute to individual differences in the experience of pain and the efficacy and reward of treatments. We explored gene variation in opioid-naïve and opioid-consuming patients undergoing elective lower extremity total joint replacement. We focused on 3 gene pathways including prostaglandin, gamma-aminobutyric acid (GABA)-ergic reward, and hepatic metabolism pathways. We report that for genes with possible or probable deleterious impact in these 3 pathways, opioid consumers had more gene variants than opioid-naïve patients (median 3 vs 1, P = .0092). We conclude that chronic opiate users may have genetic susceptibility to altered responses in reward/dependency and pain/inflammation pathways. Accepted for publication May 14, 2019. Funding: Departmental/institutional. The authors declare no conflicts of interest. Supplemental digital content is available for this article. Direct URL citations appear in the printed text and are provided in the HTML and PDF versions of this article on the journal’s website (www.anesthesia-analgesia.org). Clinical trial number and registry URL: This study is not subject to clinicaltrials.gov review as the study is not a clinical trial and does not involve an intervention or investigational use of a device or drug. Reprints will not be available from the authors. Address correspondence to Ami R. Stuart, PhD, Department of Anesthesiology, University of Utah, 30 N 1900 E RM 3C444, Salt Lake City, UT 84112. Address e-mail to ami.stuart@hsc.utah.edu. © 2019 International Anesthesia Research Society

Adultification of Black Children in Pediatric Anesthesia BACKGROUND: Unconscious racial bias in anesthesia care has been shown to exist. We hypothesized that black children may undergo inhalation induction less often, receive less support from child life, have fewer opportunities to have a family member present for induction, and receive premedication with oral midazolam less often. METHODS: We retrospectively collected data on those <18 years of age from January 1, 2012 to January 1, 2018 including age, sex, race, height, weight, American Society of Anesthesiologists (ASA) physical status, surgical service, and deidentified anesthesiology attending physician. Outcome data included mask versus intravenous induction, midazolam premedication, child life consultation, and family member presence. Racial differences between all outcomes were assessed in the cohort using a multivariable logistic regression model. RESULTS: A total of 33,717 Caucasian and 3901 black children were eligible for the study. For the primary outcome, black children 10–14 years were 1.3 times more likely than Caucasian children to receive mask induction (adjusted odds ratio [AOR], 1.3; 95% confidence interval [CI], 1.1–1.6; P = .001). Child life consultation was poorly documented (<0.5%) and not analyzed. Black children <15 years of age were at least 31% less likely than Caucasians to have a family member present for induction (AOR range, 0.4–0.6; 95% CI range, 0.31–0.84; P < .010). Black children <5 years of age were 13% less likely than Caucasians to have midazolam given preoperatively (AOR, 0.9; 95% CI, 0.8–0.9; P = .012). CONCLUSIONS: This study suggests that disparities in strategies for mitigating anxiety in the peri-induction period exist and adultification may be 1 cause for this bias. Black children 10 to 14 years of age are 1.3 times as likely as their Caucasian peers to be offered inhalation induction to reduce anxiety. However, black children are less likely to receive premedication with midazolam in the perioperative period or to have family members present at induction. The cause of this difference is unclear, and further prospective studies are needed to fully understand this difference. Accepted for publication May 7, 2019. Funding: None. The authors declare no conflicts of interest. This report describes human research. Institutional review board (IRB) contact information: Institutional Review Boards of the UM Medical School, 2800 Plymouth Rd, Building 200, Room 2086, Ann Arbor, MI 48109; e-mail: irbmed@umich.edu. The requirement for written informed consent was waived by the IRB. This report describes an observational clinical study. The author states that the report includes every item in the Enhancing the QUAlity and Transparency Of health Research (EQUATOR) checklist for case–control observational clinical studies. Reprints will not be available from the authors. Address correspondence to Anne Baetzel, MD, Department of Anesthesiology, University of Michigan Medical School, 4–911 CS Mott Children’s Hospital, 1540 E Medical Center Dr, Ann Arbor, MI 48109. Address e-mail to abaetzel@med.umich.edu. © 2019 International Anesthesia Research Society

Anesthesia Provider Training and Practice Models: A Survey of Africa BACKGROUND: In Africa, most countries have fewer than 1 physician anesthesiologist (PA) per 100,000 population. Nonphysician anesthesia providers (NPAPs) play a large role in the workforce of many low- and middle-income countries (LMICs), but little information has been systematically collected to describe existing human resources for anesthesia care models. An understanding of existing PA and NPAP training pathways and roles is needed to inform anesthesia workforce planning, especially for critically underresourced countries. METHODS: Between 2016 and 2018, we conducted electronic, phone, and in-person surveys of anesthesia providers in Africa. The surveys focused on the presence of anesthesia training programs, training program characteristics, and clinical scope of practice after graduation. RESULTS: One hundred thirty-one respondents completed surveys representing data for 51 of 55 countries in Africa. Most countries had both PA and NPAP training programs (57%; mean, 1.6 pathways per country). Thirty distinct training pathways to become an anesthesia provider could be discriminated on the basis of entry qualification, duration, and qualification gained. Of these 30 distinct pathways, 22 (73%) were for NPAPs. Physician and NPAP program durations were a median of 48 and 24 months (ranges: 36–72, 9–48), respectively. Sixty percent of NPAP pathways required a nursing background for entry, and 60% conferred a technical (eg, diploma/license) qualification after training. Physicians and NPAPs were trained to perform most anesthesia tasks independently, though few had subspecialty training (such as regional or cardiac anesthesia). CONCLUSIONS: Despite profound anesthesia provider shortages throughout Africa, most countries have both NPAP and PA training programs. NPAP training pathways, in particular, show significant heterogeneity despite relatively similar scopes of clinical practice for NPAPs after graduation. Such heterogeneity may reflect the varied needs and resources for different settings, though may also suggest lack of consensus on how to train the anesthesia workforce. Lack of consistent terminology to describe the anesthesia workforce is a significant challenge that must be addressed to accelerate workforce research and planning efforts. Accepted for publication May 16, 2019. Funding: This work received funding Hellman Family Foundation and received additional funds from the International Relations Committee of the Association of Anaesthetists/Royal College of Anesthetists for travel support. The authors declare no conflicts of interest. Supplemental digital content is available for this article. Direct URL citations appear in the printed text and are provided in the HTML and PDF versions of this article on the journal’s website (www.anesthesia-analgesia.org). T. J. Law and F. Bulamba contributed equally and share first authorship. Reprints will not be available from the authors. Address correspondence to Tyler J. Law, MD, Division of Global Health Equity, Department of Anesthesia and Perioperative Care, University of California San Francisco, 1001 Potrero Ave, Bldg 5, Rm 3C38, San Francisco, CA 94110. Address e-mail to tyler.law@ucsf.edu. © 2019 International Anesthesia Research Society