Real-Time Machine Learning Alerts to Prevent Escalation of Care: A Nonrandomized Clustered Pragmatic Clinical Trial.

OBJECTIVES: Machine learning algorithms can outperform older methods in predicting clinical deterioration, but rigorous prospective data on their real-world efficacy are limited. We hypothesized that real-time machine learning generated alerts sent directly to front-line providers would reduce escalations. DESIGN: Single-center prospective pragmatic nonrandomized clustered clinical trial. SETTING: Academic tertiary care medical center. PATIENTS: Adult patients admitted to four medical-surgical units. Assignment to intervention or control arms was determined by initial unit admission. INTERVENTIONS: Real-time alerts stratified according to predicted likelihood of deterioration sent either to the primary team or directly to the rapid response team (RRT). Clinical care and interventions were at the providers' discretion. For the control units, alerts were generated but not sent, and standard RRT activation criteria were used. MEASUREMENTS AND MAIN RESULTS: The primary outcome was the rate of escalation per 1000 patient bed days. Secondary outcomes included the frequency of orders for fluids, medications, and diagnostic tests, and combined in-hospital and 30-day mortality. Propensity score modeling with stabilized inverse probability of treatment weight (IPTW) was used to account for differences between groups. Data from 2740 patients enrolled between July 2019 and March 2020 were analyzed (1488 intervention, 1252 control). Average age was 66.3 years and 1428 participants (52%) were female. The rate of escalation was 12.3 vs. 11.3 per 1000 patient bed days (difference, 1.0; 95% CI, -2.8 to 4.7) and IPTW adjusted incidence rate ratio 1.43 (95% CI, 1.16-1.78; p < 0.001). Patients in the intervention group were more likely to receive cardiovascular medication orders (16.1% vs. 11.3%; 4.7%; 95% CI, 2.1-7.4%) and IPTW adjusted relative risk (RR) (1.74; 95% CI, 1.39-2.18; p < 0.001). Combined in-hospital and 30-day-mortality was lower in the intervention group (7% vs. 9.3%; -2.4%; 95% CI, -4.5% to -0.2%) and IPTW adjusted RR (0.76; 95% CI, 0.58-0.99; p = 0.045). CONCLUSIONS: Real-time machine learning alerts do not reduce the rate of escalation but may reduce mortality.

Poor self-rated health is associated with faster cognitive decline and greater small vessel disease in older adults with type 2 diabetes.

OBJECTIVE: Self-rated health (SRH) is a predictor for poor health outcomes and cognition. Older adults with type 2 diabetes mellitus (T2D) have multi-morbidity and greater cognitive impairment. In the present study we investigated the association of SRH with cognitive decline and brain pathology in older adults with T2D. METHODS: Participants (n = 1122) were from the Israel Diabetes and Cognitive Decline study, and SRH was categorised as low (n = 202), moderate (n = 400) or high (n = 520). Cognition was measured by four cognitive domains: episodic memory, executive functions, language, and attention/working memory. Global cognition was the average of the cognitive domains. Statistical models adjusted for sociodemographic, cardiovascular, and clinical variables. In a randomly selected subsample (n = 230) that had magnetic resonance imaging, we examined relationships between baseline SRH and brain characteristics (white matter hyperintensities [WMHs], hippocampal, and total grey matter [GM] volumes). RESULTS: Low SRH was associated with a decline in executive functions, which accelerated over time when compared to high SRH (est = -0.0036; p = <0.001). Compared to high SRH, low SRH was associated with a faster decline in global cognition (est = -0.0024; p = 0.009). Low SRH at baseline was associated with higher volumes of WMHs (est = 9.8420; p < 0.0008). SRH was not associated with other cognitive domains, or with hippocampal and total GM. CONCLUSIONS: Low SRH is associated with cognitive decline in T2D older adults and may serve as a risk assessment. WMHs may represent an underlying mechanism.

Impact of cell salvage on hematocrit and post-partum anemia in low hemorrhage risk elective cesarean delivery.

BACKGROUND: Postpartum anemia is a significant contributor to peripartum morbidity. The utilization of cell salvage in low risk cases and its impact on postpartum anemia has not been investigated. We therefore aimed to examine the impact of autologous blood transfusion/cell salvage in routine cesarean delivery on postoperative hematocrit and anemia. STUDY DESIGN AND METHODS: Retrospective cohort study from a perfusion database from a large academic center where cell salvage is performed at the discretion of the obstetrical team. Data from 99 patients was obtained. All patients were scheduled elective cesarean deliveries that took place on the labor and delivery floor. Thirty patients in the cohort had access to cell salvage where autologous blood was transfused after surgery. Pre-procedural hemoglobin/hematocrit measurements were obtained along will postpartum samples that were collected on post-partum day one. RESULTS: The median amount of blood returned to cell salvage patients was 250 mL [206-250]. Hematocrit changes in cell salvage patients was significantly smaller than controls (-1.85 [-3.87, -0.925] vs -6.4 [-8.3, -4.75]; p < 0.001). The odds of developing new anemia following surgery were cut by 74% for the cell salvage treatment group, compared to the odds for the control group (OR = 0.26 (0.07-0.78); p = 0.028) DISCUSSION: Despite losing more blood on average, patients with access to cell salvage had higher postoperative HCT, less postpartum anemia, and no difference in complications related to transfusion. The utilization of cell salvage for routine cesarean delivery warrants further research.

Motivations and demographic differences in pregnant individuals in the decision to participate in research.

PURPOSE: Although many patients agree to participate in research studies, many decline. The decision of whether or not to participate is especially complex in pregnant individuals as they may be concerned about both themselves and the fetus. We sought to understand patient reasoning for and demographic associations with participation in a trial surrounding the utility of epidural preservative-free morphine after successful vaginal delivery. METHODS: We conducted a survey-based study in which parturients were approached within 36 hr after delivery to complete a survey assessing reasons for why they participated or not in the original trial. The survey also included self-reported demographics. Survey responses were categorized as follows: active participation, passive participation, ambivalence, aversion, miscommunication, clinical difficulty, unwilling to receive placebo, and screening failures. RESULTS: The survey response rate was 47%. Having a bachelor's degree or higher was associated with participating in the study (odds ratio [OR], 1.97; 95% confidence interval [CI], 1.07 to 3.64; P = 0.03). Race and ethnicity were not predictive of participation. Participants who self-identified as Black were more likely to select reasons of aversion for why they did not participate in the trial (OR, 2.6; 95% CI, 1.00 to 6.75; P = 0.05). Seventy-three percent of participants who self-identified as Black and declined to participate selected aversion, compared with 31% of those who self-identified as non-Black. Additionally, 71% of participants who self-identified as Hispanic and declined to participate selected aversion, compared with 32% of those who self-identified as non-Hispanic. CONCLUSIONS: These findings can help identify areas for improvement of participation of pregnant individuals in research studies. Demographic associations may influence participation and reasons for participation.

RéSUMé: OBJECTIF: Bien que bon nombre de patient·es acceptent de participer à des études de recherche, beaucoup déclinent. La décision de participer ou non est particulièrement complexe chez les personnes enceintes, car elles peuvent être inquiètes pour elles-mêmes et pour le fœtus. Nous avons cherché à comprendre le raisonnement des patient·es et les associations démographiques concernant la participation à une étude portant sur l'utilité de la morphine péridurale sans agent de conservation après un accouchement vaginal réussi. MéTHODE: Nous avons mené une étude basée sur des questionnaires dans laquelle les personnes parturientes ont été approchées dans les 36 heures suivant l'accouchement afin de compléter un questionnaire évaluant les raisons pour lesquelles elles avaient participé ou non à l'étude initiale. Le questionnaire comprenait également des données démographiques autodéclarées. Les réponses au questionnaire ont été classées comme suit : participation active, participation passive, ambivalence, aversion, mauvaise communication, difficulté clinique, refus de recevoir un placebo et échecs au dépistage. RéSULTATS: Le taux de réponse était de 47 %. Le fait d'avoir un baccalauréat ou plus était associé à la participation à l'étude (rapport de cotes [RC], 1,97; intervalle de confiance [IC] à 95 %, 1,07 à 3,64; P = 0,03). La race et l'origine ethnique n'étaient pas prédictives de la participation. Les participant·es qui se sont identifié·es comme Noir·es étaient plus susceptibles de choisir des raisons d'aversion pour expliquer leur non-participation à l'étude (RC, 2,6; IC 95 %, 1,00 à 6,75; P = 0,05). Soixante-treize pour cent des participant·es qui se sont identifié·es comme Noir·es et ont refusé de participer ont choisi l'aversion, comparativement à 31 % des personnes qui se sont identifié·es comme non Noir·es. De plus, 71 % des participant·es qui se sont identifié·es comme d'origine hispanique et ont refusé de participer ont choisi l'aversion, comparativement à 32 % des personnes qui se sont identifié·es comme non Hispaniques. CONCLUSION: Ces résultats peuvent aider à identifier les domaines dans lesquels la participation des personnes enceintes aux études de recherche peut être améliorée. Les associations démographiques peuvent influencer la participation et les raisons de la participation.

Perioperative Implementation of Low-Dose Pregabalin in an Enhanced Recovery After Cardiac Surgery Protocol: A Pre-Post Observational Study.

OBJECTIVES: Determine the effect of low-dose pregabalin in the perioperative enhanced recovery after cardiac surgery protocol. DESIGN: Pre-post observational study. SETTING: Tertiary care hospital. PARTICIPANTS: Patients undergoing off-pump coronary artery bypass graft procedures. INTERVENTIONS: Pregabalin 75 mg BID for 48 hours postoperatively versus no pregabalin in a perioperative setting. MEASUREMENTS AND MAIN RESULTS: Perioperative opioid use, pain scores, length of stay, time to extubation, and mortality were all measured. Descriptive data were presented as mean (SD), median (IQR), or N (%). Ordinal and continuous data used the t-test or Kruskal-Wallis test. Categorical data were compared between groups using the chi-square test or Fisher's exact test, as appropriate. Low-dose pregabalin administration (75 mg twice daily for 48 hours after surgery) was associated with a clinically significant reduction in opioid consumption on postoperative day 0 by 30.6%, with a median requirement of 318 (233, 397) morphine milligram equivalents (MME) in the pregabalin group compared with 458 (375, 526) MME in the control group (p < 0.001). There was no significant difference in pain scores between the groups with the exception at 0-to-12 hours, during which the pregabalin group had greater pain scores (median 3.32 [1.65, 4.36] v 2.0 [0, 3.25], p = 0.013) (Table 3). Moreover, there was no significant difference in pain scores on postoperative day 1 (p = 0.492), day 2 (p = 0.442), day 3 (p = 0.237), and day 4 (p = 0.649). The difference in average Richmond Agitation Sedation Score scores was also not statistically significant between groups at 12 hours (p = 0.954) and at 24 hours (p = 0.301). The pregabalin group had no increased incidence of adverse events or any significant differences in intensive care unit length of stay, time to extubation, or mortality. CONCLUSIONS: In this evaluation of perioperative pregabalin administration for patients requiring cardiac surgery, pregabalin reduced postoperative opioid use, with significant reductions on postoperative day 0, and without any significant increase in adverse reactions. However, no differences in intensive care unit length of stay, time to extubation, or mortality were noted. The implementation of low-dose perioperative pregabalin within an Enhanced Recovery After Cardiac Surgery protocol may be effective at reducing postoperative opioid use in the immediate postoperative period, and may be safe with regard to adverse events. Ideal dosing strategies have not been determined; thus, further randomized control trials with an emphasis on limiting confounding factors need to be conducted.

Behavioral and Brain Correlates of Emotional Distress in Older Adults During COVID-19 Quarantine.

COVID-19 led to unprecedented lockdowns and changes in older adults' lives, especially those with type 2 diabetes who have high risk of complications and mortality. We investigated the associations of cognitive and motor function and gray matter volumes (GMVs) with COVID-19 lockdown-related emotional distress of type 2 diabetes older adults, participating in the Israel Diabetes and Cognitive Decline Study. We administered a questionnaire to obtain information about anxiety, depression, general well-being, and optimism during a mandated lockdown. Lower grip strength before lockdown was associated with increased sadness, anxiety, and less optimism. Slower gait speed was associated with greater sadness. Lower GMV was related to greater anxiety during the lockdown when compared with anxiety levels before the COVID-19 outbreak. Yet, global cognition was not associated with any emotional distress measure. These results support the role of good motor function on emotional well-being during acute stress and GMV as a potential underlying mechanism.

The use of transesophageal echocardiography to predict surgical complexity scoring system for degenerative mitral valve repair.

BACKGROUND: For severe mitral valve (MV) degenerative disease, repair is recommended. Prediction of repair complexity and referral to high volume centers can increase rates of successful repair. This study sought to demonstrate that TEE is a feasible imaging modality to predict the complexity of surgical MV repair. METHODS: Two hundred TEE examinations of patients who underwent MV repair (2009-2011) were retrospectively reviewed and scored by two cardiac anesthesiologists. TEE scores were compared to surgical complexity scores, which were previously assigned based on published methods. Kappa values were reported for the agreement of TEE and surgical scores. McNemar's tests were used to test the homogeneity of the marginal probabilities of different scoring categories. RESULTS: TEE scores were slightly lower (2[1,3]) than surgical scores (3[1,4]). The agreement was 66% between the scoring methods, with a moderate kappa (.46). Using surgical scores as the gold standard, 70%, 71%, and 46% of simple, intermediate and complex surgical scores, respectively, were correctly scored by TEE. P1, P2, P3, and A2 prolapse were easiest to identify with TEE and had the highest agreement with surgical scoring (P1 agreement 79% with kappa .55, P2 96% [kappa .8], P3 77% [kappa .51], A2 88% [kappa .6]). The lowest agreement between the two scores occurred with A1 prolapse (kappa .05) and posteromedial commissure prolapse (kappa .14). In the presence of significant disagreement, TEE scores were more likely to be of higher complexity than surgical. McNemar's test was significant for prolapse of P1 (p = .005), A1 (p = .025), A2 (p = .041), and the posteromedial commissure (p < .0001). CONCLUSION: TEE-based scoring is feasible for prediction of the complexity of MV surgical repair, thus allowing for preoperative stratification.

Plasma Renin Activity Increases With Cardiopulmonary Bypass and is Associated With Vasoplegia After Cardiac Surgery.

OBJECTIVES: To describe the trend in plasma renin activity over time in patients undergoing cardiac surgery on cardiopulmonary bypass, and to investigate if increased plasma renin activity is associated with postcardiopulmonary bypass vasoplegia. DESIGN: A prospective cohort study. SETTING: Patients were enrolled from June 2020 to May 2021 at a tertiary cardiac surgical institution. PATIENTS: A cohort of 100 adult patients undergoing cardiac surgery on cardiopulmonary bypass. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Plasma renin activity was measured at 5 time points: baseline, postoperatively, and at midnight on postoperative days 1, 2, and 3. Plasma renin activity and delta plasma renin activity were correlated with the incidence of vasoplegia and clinical outcomes. The median plasma renin activity increased approximately 3 times from baseline immediately after cardiac surgery, remained elevated on postoperative days 0, 1, and 2, and began to downtrend on postoperative day 3. Plasma renin activity was approximately 3 times higher at all measured time points in patients who developed vasoplegia versus those who did not. CONCLUSIONS: In patients undergoing cardiac surgery on cardiopulmonary bypass, plasma renin activity increased postoperatively and remained elevated through postoperative day 2. Additionally, patients with vasoplegic syndrome after cardiac surgery on cardiopulmonary bypass had more robust elevations in plasma renin activity than nonvasoplegic patients. These findings support the need for randomized controlled trials to determine if patients undergoing cardiac surgery with high plasma renin activity may benefit from targeted treatment with therapies such as synthetic angiotensin II.

Bleeding and ketorolac use in pediatric circumcision.

BACKGROUND: Circumcision is a common surgical procedure performed in pediatric male patients. Ketorolac is an effective adjunct in multimodal regimens for postoperative pain control. However, many urologists and anesthesiologists refrain from administering ketorolac due to concern for postoperative bleeding. AIMS: Compare the risk of clinically significant bleeding after circumcision with and without intraoperative ketorolac administration. METHODS: A single-center, retrospective cohort study was conducted of pediatric patients 1-18 years of age who underwent isolated circumcision by one urologist from 2016 to 2020. Clinically significant bleeding was defined as bleeding requiring intervention within the first 24 h of circumcision. Interventions included use of absorbable hemostats, placement of sutures, or return to the operating room. RESULTS: Of 743 patients, 314 (42.3%) did not receive ketorolac and 429 (57.7%) received intraoperative ketorolac 0.5 mg/kg. Postoperative bleeding requiring intervention occurred in one patient (0.32%) in the non-ketorolac group versus four patients (0.93%) in the ketorolac group (difference 0.6%, 95% CI [-0.8%, 2.0%], p = 0.403). CONCLUSIONS: There was no statistically significant difference in postoperative bleeding requiring intervention between the non-ketorolac and ketorolac groups. Future studies regarding the association between ketorolac and postoperative bleeding are needed.

Emotional Expression on Social Media Support Forums for Substance Cessation: Observational Study of Text-Based Reddit Posts.

BACKGROUND: Substance use disorder is characterized by distinct cognitive processes involved in emotion regulation as well as unique emotional experiences related to the relapsing cycle of drug use and recovery. Web-based communities and the posts they generate represent an unprecedented resource for studying subjective emotional experiences, capturing population types and sizes not typically available in the laboratory. Here, we mined text data from Reddit, a social media website that hosts discussions from pseudonymous users on specific topic forums, including forums for individuals who are trying to abstain from using drugs, to explore the putative specificity of the emotional experience of substance cessation. OBJECTIVE: An important motivation for this study was to investigate transdiagnostic clues that could ultimately be used for mental health outreach. Specifically, we aimed to characterize the emotions associated with cessation of 3 major substances and compare them to emotional experiences reported in nonsubstance cessation posts, including on forums related to psychiatric conditions of high comorbidity with addiction. METHODS: Raw text from 2 million posts made, respectively, in the fall of 2020 (discovery data set) and fall of 2019 (replication data set) were obtained from 394 forums hosted by Reddit through the application programming interface. We quantified emotion word frequencies in 3 substance cessation forums for alcohol, nicotine, and cannabis topic categories and performed comparisons with general forums. Emotion word frequencies were classified into distinct categories and represented as a multidimensional emotion vector for each forum. We further quantified the degree of emotional resemblance between different forums by computing cosine similarity on these vectorized representations. For substance cessation posts with self-reported time since last use, we explored changes in the use of emotion words as a function of abstinence duration. RESULTS: Compared to posts from general forums, substance cessation posts showed more expressions of anxiety, disgust, pride, and gratitude words. "Anxiety" emotion words were attenuated for abstinence durations >100 days compared to shorter durations (t12=3.08, 2-tailed; P=.001). The cosine similarity analysis identified an emotion profile preferentially expressed in the cessation posts across substances, with lesser but still prominent similarities to posts about social anxiety and attention-deficit/hyperactivity disorder. These results were replicated in the 2019 (pre-COVID-19) data and were distinct from control analyses using nonemotion words. CONCLUSIONS: We identified a unique subjective experience phenotype of emotions associated with the cessation of 3 major substances, replicable across 2 time periods, with changes as a function of abstinence duration. Although to a lesser extent, this phenotype also quantifiably resembled the emotion phenomenology of other relevant subjective experiences (social anxiety and attention-deficit/hyperactivity disorder). Taken together, these transdiagnostic results suggest a novel approach for the future identification of at-risk populations, allowing for the development and deployment of specific and timely interventions.

Accurate protamine:heparin matching (not just smaller protamine doses) decreases postoperative bleeding in cardiac surgery; results from a high-volume academic medical center.

BACKGROUND: A multidisciplinary Quality Assurance/Performance Improvement study to identify the incidence of "heparin rebound" in our adult cardiac surgical population instead detected a thromboelastometry pattern suggestive of initial protamine overdose in 34% despite Hepcon-guided anticoagulation management. Analysis of our practice led to an intervention that made an additional lower-range Hepcon cartridge available to the perfusionists. METHODS: One year later, an IRB-approved retrospective study was conducted in >500 patients to analyze the effects of the intervention, specifically focusing on the impact of the initial protamine dose accuracy and 18-h mediastinal chest tube drainage (MCTd). RESULTS: No differences were observed between group demographics, surgical procedures, duration of CPB or perioperative blood product transfusion. Both groups were managed using the same perfusion and anesthesia equipment, strategies, and protocols. The median initial protamine dose decreased by 19% (p < .001) in the intervention group (170 [IQR 140-220] mg; n = 295) versus the control group (210 [180-250] mg; n = 257). Mean 18-h MCTd decreased by 13% (p < .001) in the intervention group (405.15 ± 231.54 mL; n = 295) versus the control group (466.13 ± 286.73 mL; n = 257). Covariate-adjusted mixed effects model showed a significant reduction of MCTd in the intervention group, starting from hour 11 after surgery (group by time interaction p = .002). CONCLUSION: Though previous investigators have associated lower protamine doses with less MCTd, this study demonstrates that more accurately matching the initial protamine dose to the remaining circulating heparin concentration reduces postoperative bleeding.

A censored quantile regression approach for relative survival analysis: Relative survival quantile regression.

We propose a censored quantile regression model for the analysis of relative survival data. We create a hybrid data set consisting of the study observations and counterpart randomly sampled pseudopopulation observations imputed from population life tables that adjust for expected mortality. We then fit a censored quantile regression model to the hybrid data incorporating demographic variables (e.g., age, biologic sex, calendar time) corresponding to the population life tables of demographically-similar individuals, a population versus study covariate, and its interactions with the variables of interest. These latter variables can be interpreted as relative survival parameters that depict the differences in failure quantiles between the study participants and their population counterparts.

Self-reported Race/Ethnicity and Intraoperative Occult Hypoxemia: A Retrospective Cohort Study.

BACKGROUND: Pulse oximetry is ubiquitous in anesthesia and is generally a reliable noninvasive measure of arterial oxygen saturation. Concerns regarding the impact of skin pigmentation and race/ethnicity on the accuracy of pulse oximeter accuracy exist. The authors hypothesized a greater prevalence of occult hypoxemia (arterial oxygen saturation [Sao2] less than 88% despite oxygen saturation measured by pulse oximetry [Spo2] greater than 92%) in patients undergoing anesthesia who self-reported a race/ethnicity other than White. METHODS: Demographic and physiologic data, including self-reported race/ethnicity, were extracted from a departmental data warehouse for patients receiving an anesthetic that included at least one arterial blood gas between January 2008 and December 2019. Calculated Sao2 values were paired with concurrent Spo2 values for each patient. Analysis to determine whether Black, Hispanic, Asian, or Other race/ethnicities were associated with occult hypoxemia relative to White race/ethnicity within the Spo2 range of 92 to 100% was completed. RESULTS: In total, 151,070 paired Sao2-Spo2 readings (70,722 White; 16,011 Black; 21,223 Hispanic; 8,121 Asian; 34,993 Other) from 46,253 unique patients were analyzed. The prevalence of occult hypoxemia was significantly higher in Black (339 of 16,011 [2.1%]) and Hispanic (383 of 21,223 [1.8%]) versus White (791 of 70,722 [1.1%]) paired Sao2-Spo2 readings (P < 0.001 for both). In the multivariable analysis, Black (odds ratio, 1.44 [95% CI, 1.11 to 1.87]; P = 0.006) and Hispanic (odds ratio, 1.31 [95% CI, 1.03 to 1.68]; P = 0.031) race/ethnicity were associated with occult hypoxemia. Asian and Other race/ethnicity were not associated with occult hypoxemia. CONCLUSIONS: Self-reported Black and Hispanic race/ethnicity are associated with a greater prevalence of intraoperative occult hypoxemia in the Spo2 range of 92 to 100% when compared with self-reported White race/ethnicity.

Research priorities in liver transplant anesthesiology: Results of a survey of liver transplant anesthesiologists.

Optimal perioperative care contributes to improved patient outcomes, as demonstrated in the field of liver transplant (LT). The evolution in perioperative care over the past two decades has been driven by research in areas such as preoperative testing, coagulation management, and intraoperative monitoring. However, much of this research is driven by local institutional pressures and practices with a dearth of studies emanating from research consortia or other groups of experts within the field. To better characterize the top research questions in the field, we queried a group of 128 LT anesthesiologists representing 87 international liver transplant centers with a response from 71 practitioners (59.2%). Three experts then codified the responses into the top 20 questions, which were sent to the survey recipients as a second survey to rank order. Seventy-five respondents (61.5%) provided responses, which were merged into a weighted ranked priority list and analyzed by respondent location and center size. The highest ranked question was, "What intraoperative anesthetic management/interventions affect graft outcome?" Most of the top research questions focused on preoperative risk factor management or optimization and intraoperative management techniques. In general, this priorities list may serve as a guide for transplant anesthesiology researchers to focus future research endeavors on shared interests that improve patient care.

The relationship between INTEM/HEPTEM coagulation time ratio and heparin plasma concentration in obstetric patients: an exploratory in vitro investigation.

PURPOSE: Unfractionated heparin continues to be one of the main agents used for thromboprophylaxis in obstetrics, which can complicate the placement of neuraxial anesthetics. In this study, we explored the relationship between a point-of-care coagulation test (thromboelastometry) and plasma heparin concentrations in vitro. METHODS: We obtained blood from consenting obstetric patients with uncomplicated pregnancies in their third trimester who were not in labour and had a specific hematocrit range. Blood was processed and analyzed. We added increasing amounts of unfractionated heparin to samples from 0 to 0.3 U·mL-1 in 0.05 U·mL-1 increments to simulate increasing doses of unfractionated heparin. We performed INTEM and HEPTEM testing in parallel with activated partial thromboplastin time (aPTT) testing. We created a model of the relationship between heparin concentration and the INTEM/HEPTEM coagulation time (IH CT) ratio using nonlinear regression. A similar model for aPTT was also created. RESULTS: Seventy-seven patients were included in the study. Only one concentration of heparin was added to blood samples of each patient. At a concentration of 0.05 U·mL-1, the IH CT ratio was less than or equal to 1.1 in 9/11 (82%) samples. Activated partial thromboplastin time was not prolonged (> 35 sec) until a concentration of 0.1 U·mL-1 heparin was added. In all samples, the IH CT ratio was prolonged at a concentration ≥ 0.2 U·mL-1 as measured by thromboelastometry; however, at no concentration of heparin was aPTT prolonged in all samples. CONCLUSION: The point-of-care IH CT ratio may be useful in identifying the presence of little to no heparin activity. Further research is needed to determine if this ratio can predict heparin activity in vivo.

RéSUMé: OBJECTIF: L'héparine non fractionnée demeure l'un des principaux agents utilisés pour la thromboprophylaxie en obstétrique, ce qui peut compliquer la mise en place d'anesthésiques neuraxiaux. Dans cette étude, nous avons exploré la relation entre un test de coagulation au chevet de la patiente (thromboélastométrie) et les concentrations plasmatiques d'héparine in vitro. MéTHODE: Nous avons obtenu du sang de patientes obstétricales consentantes ayant des grossesses non compliquées au cours de leur troisième trimestre qui n'étaient pas en travail et dont l'hématocrite était dans une plage spécifique. Le sang a été traité et analysé. Des quantités croissantes d'héparine non fractionnée ont été ajoutées à des échantillons de 0 à 0,3 U·mL−1 en incréments de 0,05 U·mL−1 pour simuler des doses croissantes d'héparine non fractionnée. Des tests INTEM et HEPTEM ont été réalisés en parallèle avec des tests de temps de thromboplastine partielle activée (aPTT). Un modèle de la relation entre la concentration d'héparine et le ratio temps de coagulation INTEM/HEPTEM (IH CT) a été créé en utilisant une régression non linéaire. Un modèle similaire pour l'aPTT a également été créé. RéSULTATS: Soixante-dix-sept patientes ont été incluses dans l'étude. Une seule concentration d'héparine a été ajoutée aux échantillons de sang de chaque patiente. À une concentration de 0,05 U·mL−1, le ratio IH CT était inférieur ou égal à 1,1 dans 9/11 échantillons (82 %). L'aPTT n'a pas été prolongé (> 35 sec) jusqu'à ce qu'une concentration d'héparine de 0,1 U·mL−1 soit ajoutée. Dans tous les échantillons, le ratio IH CT a été prolongé à une concentration ≥ 0,2 U·mL−1 telle que mesurée par thromboélastométrie; cependant, dans tous les échantillons, aucune concentration d'héparine n'a prolongé l'aPTT. CONCLUSION: Le ratio IH CT au chevet de la patiente peut être utile pour identifier la présence d'une activité d'héparine faible ou nulle. D'autres recherches sont nécessaires pour déterminer si ce ratio peut prédire l'activité héparinique in vivo.

Serratus Anterior Plane Block Versus Intercostal Block with Incision Infiltration in Robotic-Assisted Thoracoscopic Surgery: A Randomized Controlled Pilot Trial.

OBJECTIVES: Patients undergoing robotic video-assisted thoracoscopic surgery (rVATS) report significant postoperative pain. Both the serratus anterior plane block (SAPB) and the surgical intercostal block (IB) (performed by a surgeon from within the thorax), along with incision infiltration (II), are distinct modalities that target the lateral cutaneous branches of intercostal nerves and are acceptable analgesic modalities in an enhanced recovery after rVATS surgery. DESIGN: Prospective, double-blinded, randomized, controlled pilot trial with 65 patients to assess the difference in analgesia quality between the SAPB and IB+II in rVATS. SETTING: Major academic teaching hospital. PARTICIPANTS: The inclusion criteria included ASA physical status I-IV, ages 18-to-75 undergoing an elective, unilateral rVATS procedure. INTERVENTIONS: Patients were randomized to receive either an ultrasound-guided SAPB at the end of their surgery, using a 20-mL mixture consisting of 10 mL of liposomal bupivacaine (133 mg) and 10 mL 0.25% bupivacaine, or IB+II, using a 20-mL mixture consisting of 10 mL of liposomal bupivacaine (133 mg) and 10 mL 0.5% bupivacaine prior to skin closure by the surgeon. RESULTS: The primary outcome was the amount of postoperative opioid consumption in morphine milliequivalents [MME] during the first 24 hours after surgery. Secondary outcomes were time to first analgesic request, VAS scores at zero, two, six, 18, or 24 hours at rest, and PACU, ICU, or hospital lengths of stay (LOS). There were no differences in any outcomes between the groups. CONCLUSIONS: Both SAPB and IB+II are comparable analgesic modalities for rVATS procedures.

The Optimal Cell Salvage Settings to Maximize Hematocrit and Minimize Potassium Using the Cobe BRAT2 Autologous Blood Recovery Unit.

OBJECTIVE: The objective was to determine the optimal cell saver device settings (infusion rate and wash rate) at which hematocrit is preserved and potassium and lactate are removed from banked red blood cells (RBC). DESIGN: Red cells were washed using the Cobe BRAT 2 Autologous Blood Recovery Unit and sampled for electrolyte composition and hematocrit pre- and postwash. SETTING: This was a single-center study. INTERVENTIONS: Red cells were washed using six infusion rates (100-1,000 mL/min) and six wash rates (100-1,000 mL/min) for a total of 36 combinations. Hematocrit, potassium, glucose, and lactate were evaluated before and after washing. MEASUREMENTS AND MAIN RESULTS: At wash rates ≤400 mL/min, hematocrit increased independent of infusion rate. At wash rates ≥400 mL/min, slower infusion rates were associated with higher hematocrit compared to faster infusion rates (p < 0.0001 for a wash rate 400-800 mL/min, p < 0.0005 for a wash rate 1,000 mL/min). Maximal wash speeds were associated with decreasing hematocrit. Infusion and wash rate were both independent predictors of potassium change; slower rates were associated with a larger decrease in potassium. Glucose decreased proportionally as infusion and wash rate decreased. Lactate did not show an association with either infusion or wash rate. CONCLUSION: Red-cell washing produces higher hematocrit and lower potassium as infusion rate and wash rate decrease. A 340-mL unit of RBC can be processed in 4.26 minutes without loss of hematocrit or an increase in potassium when both infusion and wash rates are set to 400 mL/min.

Stability in BMI over time is associated with a better cognitive trajectory in older adults.

OBJECTIVE: Evidence on simultaneous changes in body mass index (BMI) and cognitive decline, which better reflect the natural course of both health phenomena, is limited. METHODS: We capitalized on longitudinal data from 15,977 initially non-demented elderly from the Alzheimer's Disease Centers followed for 5 years on average. Changes in BMI were defined as (1) last minus first BMI, (2) mean of all follow-up BMIs minus first BMI, and (3) standard deviation of BMI change from baseline and all follow-up visits (representing variability). RESULTS: Participants with significant changes in BMI (increase or decrease of ≥5%), or who had greater variability in BMI, had faster cognitive decline. This pattern was consistent irrespective of normal (BMI < 25; N = 5747), overweight (25 ≤ BMI < 30; N = 6302), or obese (BMI ≥ 30; N = 3928) BMI at baseline. CONCLUSIONS: Stability in BMI predicts better cognitive trajectories suggesting clinical value in tracking BMI change, which is simple to measure, and may point to individuals whose cognition is declining.

Processed intraoperative burst suppression and postoperative cognitive dysfunction in a cohort of older noncardiac surgery patients.

Postoperative cognitive dysfunction (POCD) is a decline in cognitive test performance which persists months after surgery. There has been great interest in the anesthesia community regarding whether variables generated by commercially available processed EEG monitors originally marketed to prevent awareness under anesthesia can be used to guide intraoperative anesthetic management to prevent POCD. Processed EEG monitors represent an opportunity for anesthesiologists to directly monitor the brain even if they have not been trained to interpret EEG waveforms. There is continued equipoise regarding whether any of the variables generated by the machines' interpretation of raw data are associated with POCD. Most literature has focused on the depth of anesthesia number, however recent studies have shown that processed depth may not be accurate in older age groups due to reduced alpha band power. Burst suppression is an encephalographic pattern of high voltage activity alternating with periods of electrical silence and is another marker of depth which can be obtained from commercial processed EEG monitors. We performed a prospective cohort study to determine whether burst suppression and burst suppression ratio as measured by the BIS Monitor (Bispectral Index, BIS Medtronic, Boulder CO), is associated with cognitive dysfunction 3 months after surgery. We recruited 167 elective surgery patients, 65 years of age and older, anticipated to require at least 2 day inpatient admission. Our main outcome measure was cognitive decline in composite z-score on the Alzheimer's Disease Research Center UDS Battery of at least 1 standard deviation 3 months after surgery relative to preoperative baseline. 14% experienced POCD, this group was older (72 [70, 74] versus 70 [67, 75] years), and had frailty scores as measured by the FRAIL Scale (2 [0, 3] versus 1 [0, 2]) and lower baseline z-scores (- 0.2 [- 0.6, 0.5] versus 0.1 [- 0.3, 0.5]). There was a univariable association between suppression ratio > 10 (SR > 10) and POCD (4.8 [0, 37.3] versus 15.4 [4.0-142.4] min), p = .038. However, after adjustment this relationship did not persist, only anesthetic technique, age, and pain remained in the model. In our cohort of older elective noncardiac surgery patients we found a marginal association between processed burst suppression (total burst suppression p = .067, SR > 5 p = .052, SR > 10.038) which did not persist in a multivariable model. Patients with POCD had almost twice the number of minutes of burst suppression, and three times the amount of time for SR > 5 and > 10. Our finding may be a limitation of the monitor's ability to detect burst suppression. The consistent trend towards more intraoperative burst suppression in patients who developed POCD suggests that future studies are needed to investigate the relationship of raw intraoperative burst suppression and POCD.Trial registry Clinical trial number and registry URL: Optimizing Postoperative Cognitive Dysfunction in the Elderly-PRESERVE, Clinical Trials Gov# NCT02650687; https://clinicaltrials.gov/ct2/show/NCT02650687 .

Evaluation of the addition of bupivacaine to intrathecal morphine for intraoperative and postoperative pain management in open liver resections.

BACKGROUND: Intrathecal morphine is a popular and effective regional technique for pain control after open liver resection, but its delayed analgesic onset makes it less useful for the intraoperative period. The aim of this retrospective study was to compare the analgesic efficacy and other secondary benefits of the addition of hyperbaric bupivacaine to intrathecal morphine ± fentanyl. We hypothesized that bupivacaine could serve as an analgesic "bridge" prior to the onset of intrathecal morphine/fentanyl thereby lowering opioid consumption and enhancing recovery. METHODS: Cumulative intraoperative and postoperative opioid consumption as well as other intra- and postoperative variables were collected and compared between groups receiving intrathecal morphine alone or intrathecal morphine ± hyperbaric bupivacaine. RESULTS: Sixty-eight patients were selected for inclusion. Cumulative intraoperative morphine consumption was significantly reduced in the bupivacaine group while other intraoperative parameters such as intravenous fluids, blood loss, and vasopressors did not differ. There was a statistically significant improvement in time to first bowel movement in the experimental group. DISCUSSION: The intraoperative opioid sparing effects and improved time to bowel function with the addition of hyperbaric bupivacaine to intrathecal morphine may make this technique an easy and low risk method of enhancing recovery after open liver resection.