Etomidate versus Ketamine as Prehospital Induction Agent in Patients with Suspected Severe Traumatic Brain Injury.

BACKGROUND: Severe traumatic brain injury is a leading cause of morbidity and mortality among young people around the world. Prehospital care focuses on the prevention and treatment of secondary brain injury and commonly includes tracheal intubation after induction of general anesthesia. The choice of induction agent in this setting is controversial. This study therefore investigated the association between the chosen induction medication etomidate versus S(+)-ketamine and the 30-day mortality in patients with severe traumatic brain injury who received prehospital airway management in the Netherlands. METHODS: This study is a retrospective analysis of the prospectively collected observational data of the Brain Injury: Prehospital Registry of Outcomes, Treatments and Epidemiology of Cerebral Trauma (BRAIN-PROTECT) cohort study. Patients with suspected severe traumatic brain injury who were transported to a participating trauma center and who received etomidate or S(+)-ketamine for prehospital induction of anesthesia for advanced airway management were included. Statistical analyses were performed with multivariable logistic regression and inverse probability of treatment weighting analysis. RESULTS: In total, 1,457 patients were eligible for analysis. No significant association between the administered induction medication and 30-day mortality was observed in unadjusted analyses (32.9% mortality for etomidate versus 33.8% mortality for S(+)-ketamine; P = 0.716; odds ratio, 1.04; 95% CI, 0.83 to 1.32; P = 0.711), as well as after adjustment for potential confounders (odds ratio, 1.08; 95% CI, 0.67 to 1.73; P = 0.765; and risk difference 0.017; 95% CI, -0.051 to 0.084; P = 0.686). Likewise, in planned subgroup analyses for patients with confirmed traumatic brain injury and patients with isolated traumatic brain injury, no significant differences were found. Consistent results were found after multiple imputations of missing data. CONCLUSIONS: The analysis found no evidence for an association between the use of etomidate or S(+)-ketamine as an anesthetic agent for intubation in patients with traumatic brain injury and mortality after 30 days in the prehospital setting, suggesting that the choice of induction agent may not influence the patient mortality rate in this population.

Effectiveness of tranexamic acid in burn patients undergoing surgery - a systematic review and meta-analysis.

BACKGROUND: Reducing blood loss during excisional surgery in burn patients remains a challenge. Tranexamic acid during surgery can potentially reduce blood loss. The use of tranexamic acid during excisional surgery in burn patients has recently been described in a review and meta-analysis. However, quality assessment on studies included was not performed and this review did not apply independent reviewers. Quality assessment of studies investigating the effectiveness of tranexamic acid in burn patients is crucial before concusions can be drawn. Therefore, we conducted a systematic review and meta-analysis of the literature investigating the effectiveness of tranexamic acid in burn patients undergoing surgery. METHODS: A systematic review and meta-analysis of the literature was conducted. The study was pre-registered in PROSPERO database (CRD42023396183). RESULTS: Five studies including two randomised controlled trials (RCTs) with a total of 303 patients were included. Risk of bias of the included studies was moderate to high. Individual results of the studies were heterogeneous. In three studies of moderate quality the administration of tranexamic acid resulted in a reduction of blood loss per unit excised area, accounting as moderate level of evidence. In two low-quality studies and one moderate quality study the administration of tranexamic acid resulted in a reduction of transfused packed Red Blood Cells (pRBC's), accounting for moderate level of evidence. Postoperative haemoglobin levels were higher after tranexamic acid administration in one study, accounting for insufficient evidence. Meta-analysis pooling overall blood loss from two separate RCTs failed to detect a statistically significant reduction. Substantial heterogeneity was observed. CONCLUSIONS: Moderate level of evidence indicates that tranexamic acid reduces blood loss per unit of excised area and transfusion of packed Red Blood Cells. Results indicate that tranexamic acid can be beneficial in burn patients undergoing surgery. More high-quality research is needed to confirm these results. Future studies should focus on the dosing of tranexamic acid, the administration approaches, and even consider combining these approaches. TRIAL REGISTRATION: PROSPERO: CRD42023396183.

Prehospital Intubation of Patients with Severe Traumatic Brain Injury: A Dutch Nationwide Trauma Registry Analysis.

OBJECTIVE: Patients with severe traumatic brain injury (TBI) are commonly intubated during prehospital treatment despite a lack of evidence that this is beneficial. Accumulating evidence even suggests that prehospital intubation may be hazardous, in particular when performed by inexperienced EMS clinicians. To expand the limited knowledge base, we studied the relationship between prehospital intubation and hospital mortality in patients with severe TBI in a large Dutch trauma database. We specifically hypothesized that the relationship differs depending on whether a physician-based emergency medical service (EMS) was involved in the treatment, as opposed to intubation by paramedics. METHODS: A retrospective analysis was performed using the Dutch Nationwide Trauma Registry that includes all trauma patients in the Netherlands who are admitted to any hospital with an emergency department. All patients treated for severe TBI (Head Abbreviated Injury Scale score ≥4) between January 2015 and December 2019 were selected. Multivariable logistic regression was used to assess the relationship between prehospital intubation and mortality while adjusting for potential confounders. An interaction term between prehospital intubation and the involvement of physician-based EMS was added to the model. Complete case analysis as well as multiple imputation were performed. RESULTS: 8946 patients (62% male, median age 63 years) were analyzed. The hospital mortality was 26.4%. Overall, a relationship between prehospital intubation and higher mortality was observed (complete case: OR 1.86, 95% CI 1.35-2.57, p < 0.001; multiple imputation: OR 1.92, 95% CI 1.56-2.36, p < 0.001). Adding the interaction revealed that the relationship of prehospital intubation may depend on whether physician-based EMS is involved in the treatment (complete case: p = 0.044; multiple imputation: p = 0.062). Physician-based EMS involvement attenuated but did not completely remove the detrimental association between prehospital intubation and mortality. CONCLUSION: The data do not support the common practice of prehospital intubation. The effect of prehospital intubation on mortality might depend on EMS clinician experience, and it seems prudent to involve prehospital personnel well proficient in prehospital intubation whenever intubation is potentially required. The decision to perform prehospital intubation should not merely be based on the largely unsupported dogma that it is generally needed in severe TBI, but should rather individually weigh potential benefits and harms.

Dexmedetomidine Clearance Decreases with Increasing Drug Exposure: Implications for Current Dosing Regimens and Target-controlled Infusion Models Assuming Linear Pharmacokinetics.

BACKGROUND: Numerous pharmacokinetic models have been published aiming at more accurate and safer dosing of dexmedetomidine. The vast majority of the developed models underpredict the measured plasma concentrations with respect to the target concentration, especially at plasma concentrations higher than those used in the original studies. The aim of this article was to develop a dexmedetomidine pharmacokinetic model in healthy adults emphasizing linear versus nonlinear kinetics. METHODS: The data of two previously published clinical trials with stepwise increasing dexmedetomidine target-controlled infusion were pooled to build a pharmacokinetic model using the NONMEM software package (ICON Development Solutions, USA). Data from 48 healthy subjects, included in a stratified manner, were utilized to build the model. RESULTS: A three-compartment mamillary model with nonlinear elimination from the central compartment was superior to a model assuming linear pharmacokinetics. Covariates included in the final model were age, sex, and total body weight. Cardiac output did not explain between-subject or within-subject variability in dexmedetomidine clearance. The results of a simulation study based on the final model showed that at concentrations up to 2 ng · ml-1, the predicted dexmedetomidine plasma concentrations were similar between the currently available Hannivoort model assuming linear pharmacokinetics and the nonlinear model developed in this study. At higher simulated plasma concentrations, exposure increased nonlinearly with target concentration due to the decreasing dexmedetomidine clearance with increasing plasma concentrations. Simulations also show that currently approved dosing regimens in the intensive care unit may potentially lead to higher-than-expected dexmedetomidine plasma concentrations. CONCLUSIONS: This study developed a nonlinear three-compartment pharmacokinetic model that accurately described dexmedetomidine plasma concentrations. Dexmedetomidine may be safely administered up to target-controlled infusion targets under 2 ng · ml-1 using the Hannivoort model, which assumed linear pharmacokinetics. Consideration should be taken during long-term administration and during an initial loading dose when following the dosing strategies of the current guidelines.

External Validation of the ACTA-PORT Transfusion Risk Score in Older Cardiac Surgery Patients at Risk of Frailty.

OBJECTIVES: Accurate preoperative transfusion risk stratification may serve to better manage older patients undergoing cardiac surgery. Therefore, the aim of the present study was to externally validate the existing Association of Cardiothoracic Anesthetists perioperative risk of blood transfusion (ACTA-PORT) score in a population ≥70 years of age scheduled for cardiac surgery. Furthermore, the study authors investigated the additional prognostic value of individual frailty variables to this transfusion risk score. DESIGN: A retrospective analysis. SETTING: At a tertiary-care hospital. PARTICIPANTS: Five hundred seven patients aged ≥70 years undergoing elective cardiac surgery from July 2015 to August 2017. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The primary outcome was the administration of a perioperative blood transfusion. Frailty domains were assessed in a preanesthesia geriatric assessment, and a priori selection of biomarkers derived from blood was determined. The original ACTA-PORT score resulted in a c-statistic of 0.78 (95% confidence interval 0.74-0.82), with moderate calibration in predicting perioperative allogeneic transfusion in older patients undergoing cardiac surgery. Model updating, using the closed testing procedure, resulted in model revision with a higher discriminatory performance (c-statistic of 0.83, 95% confidence interval 0.79-0.86) and corrected calibration slope. Iron deficiency, impaired nutritional status, and physical impairment were associated with perioperative transfusions. The addition of individual frailty variables to the updated ACTA-PORT model did not result in improved predictive performance. CONCLUSIONS: External validation of the original ACTA-PORT score showed good discrimination and moderate calibration in older patients at risk of frailty undergoing cardiac surgery. Updating the original ACTA-PORT improved the predictive performance. Careful evaluation of additional frailty domains did not add prognostic value to the ACTA-PORT score.

Antifibrinolytics in the treatment of traumatic brain injury.

PURPOSE OF REVIEW: Traumatic brain injury (TBI) is a leading cause of trauma-related deaths, and pharmacologic interventions to limit intracranial bleeding should improve outcomes. Tranexamic acid reduces mortality in injured patients with major systemic bleeding, but the effects of antifibrinolytic drugs on outcomes after TBI are less clear. We therefore summarize recent evidence to guide clinicians on when (not) to use antifibrinolytic drugs in TBI patients. RECENT FINDINGS: Tranexamic acid is the only antifibrinolytic drug that has been studied in patients with TBI. Several recent studies failed to conclusively demonstrate a benefit on survival or neurologic outcome. A large trial with more than 12 000 patients found no significant effect of tranexamic acid on head-injury related death, all-cause mortality or disability across the overall study population, but observed benefit in patients with mild to moderate TBI. Observational evidence signals potential harm in patients with isolated severe TBI. SUMMARY: Given that the effect of tranexamic acid likely depends on a variety of factors, it is unlikely that a 'one size fits all' approach of administering antifibrinolytics to all patients will be helpful. Tranexamic acid should be strongly considered in patients with mild to moderate TBI and should be avoided in isolated severe TBI.

Breathing variability-implications for anaesthesiology and intensive care.

The respiratory system reacts instantaneously to intrinsic and extrinsic inputs. This adaptability results in significant fluctuations in breathing parameters, such as respiratory rate, tidal volume, and inspiratory flow profiles. Breathing variability is influenced by several conditions, including sleep, various pulmonary diseases, hypoxia, and anxiety disorders. Recent studies have suggested that weaning failure during mechanical ventilation may be predicted by low respiratory variability. This review describes methods for quantifying breathing variability, summarises the conditions and comorbidities that affect breathing variability, and discusses the potential implications of breathing variability for anaesthesia and intensive care.

Epidemiology, Prehospital Characteristics and Outcomes of Severe Traumatic Brain Injury in The Netherlands: The BRAIN-PROTECT Study.

OBJECTIVE: A thorough understanding of the epidemiology, patient characteristics, trauma mechanisms, and current outcomes among patients with severe traumatic brain injury (TBI) is important as it may inform potential strategies to improve prehospital emergency care. The aim of this study is to describe the prehospital epidemiology, characteristics and outcome of (suspected) severe TBI in the Netherlands. METHODS: The BRAIN-PROTECT study is a prospective observational study on prehospital management of patients with severe TBI in the Netherlands. The study population comprised all consecutive patients with clinical suspicion of TBI and a prehospital GCS score ≤ 8, who were managed by one of the 4 Helicopter Emergency Medical Services (HEMS). Patients were followed-up in 9 trauma centers until 1 year after injury. Planned sub-analyses were performed for patients with "confirmed" and "isolated" TBI. RESULTS: Data from 2,589 patients, of whom 2,117 (81.8%) were transferred to a participating trauma center, were analyzed. The incidence rate of prehospitally suspected and confirmed severe TBI were 3.2 (95% CI: 3.1;3.4) and 2.7 (95% CI: 2.5;2.8) per 100,000 inhabitants per year, respectively. Median patient age was 46 years, 58.4% were involved in traffic crashes, of which 37.4% were bicycle related. 47.6% presented with an initial GCS of 3. The median time from HEMS dispatch to hospital arrival was 54 minutes. The overall 30-day mortality was 39.0% (95% CI: 36.8;41.2). CONCLUSION: This article summarizes the prehospital epidemiology, characteristics and outcome of severe TBI in the Netherlands, and highlights areas in which primary prevention and prehospital care can be improved.

Pre-hospital transfusion of red blood cells. Part 1: A scoping review of current practice and transfusion triggers.

OBJECTIVES: The primary aim of this scoping review is to describe the current use of pre-hospital transfusion of red blood cells (PHTRBC) and to evaluate criteria used to initiate PHTRBC. The effects on patients' outcomes will be reviewed in Part 2. BACKGROUND: Haemorrhage is a preventable cause of death in trauma patients, and transfusion of red blood cells is increasingly used by Emergency Medical Services (EMS) for damage control resuscitation. However, there are no guidelines and little consensus on when to initiate PHTRBC. METHODS: PubMed and Web of Science were searched through January 2019; 71 articles were included. RESULTS: Transfusion triggers vary widely and involve vital signs, clinical signs of poor tissue perfusion, point of care measurements and pre-hospital ultrasound imaging. In particular, hypotension (most often defined as systolic blood pressure ≤ 90 mmHg), tachycardia (most often defined as heart rate ≥ 120/min), clinical signs of poor perfusion (eg, prolonged capillary refill time or changes in mental status) and injury type (ie, penetrating wounds) are common pre-hospital transfusion triggers. CONCLUSIONS: PHTRBC is increasingly used by Emergency Medical Services, but guidelines on when to initiate transfusion are lacking. We identified the most commonly used transfusion criteria, and these findings may provide the basis for consensus-based pre-hospital transfusion protocols.

Pre-hospital transfusion of red blood cells. Part 2: A systematic review of treatment effects on outcomes.

The primary aim of this systematic review is to describe the effects of prehospital transfusion of red blood cells (PHTRBC) on patient outcomes. Damage control resuscitation attempts to prevent death through haemorrhage in trauma patients. In this context, transfusion of red blood cells is increasingly used by emergency medical services (EMS). However, evidence on the effects on outcomes is scarce. PubMed and Web of Science were searched through January 2019; 55 articles were included. No randomised controlled studies were identified. While several observational studies suggest an increased survival after PHTRBC, consistent evidence for beneficial effects of PHTRBC on survival was not found. PHTRBC appears to improve haemodynamic parameters, but there is no evidence that shock on arrival to hospital is averted, nor of an association with trauma induced coagulopathy or with length of stay in hospitals or intensive care units. In conclusion, PHTRBC is increasingly used by EMS, but there is no strong evidence for effects of PHTRBC on mortality. Further research with study designs that allow causal inferences is required for more conclusive evidence. The combination of PHTRBC with plasma, as well as the use of individualised transfusion criteria, may potentially show more benefits and should be thoroughly investigated in the future. The review was registered at Prospero (CRD42018084658).

Prehospital cricothyrotomies in a helicopter emergency medical service: analysis of 19,382 dispatches.

BACKGROUND: Creating a patent airway by cricothyrotomy is the ultimate maneuver to allow oxygenation (and ventilation) of the patient. Given the rarity of airway management catastrophes necessitating cricothyrotomy, sufficiently sized prospective randomized trials are difficult to perform. Our Helicopter Emergency Medical Service (HEMS) documents all cases electronically, allowing a retrospective analysis of a larger database for all cases of prehospital cricothyrotomy. METHODS: We analyzed all 19,382 dispatches of our HEMS 'Lifeliner 1', since set-up of a searchable digital database. This HEMS operates 24/7, covering ~ 4.5 million inhabitants of The Netherlands. The potential cases were searched and cross-checked in two independent databases. RESULTS: We recorded n = 18 cases of prehospital cricothyrotomy. In all 18 cases, less invasive airway techniques, e.g., supraglottic devices, were attempted before cricothyrotomy. With exception of 2 cases, at least one attempt of orotracheal intubation had been performed before cricothyrotomy. Out of the 18 cases, 4 were performed by puncture-based technique (Melker), the remaining 14 cases by surgical technique. Indications for cricothyrotomy were diverse, dividable into 9 trauma cases and 9 medical cases. The procedure was successful in all but one case (17/18, i.e., 94%; with a 95% confidence interval of 72.7-99.9%). Outcome was such that 6/18 patients arrived at the hospital alive. Long term outcome was poor, with only 2/18 patients discharged from hospital alive. CONCLUSIONS: Cricothyrotomy remains, although rare, a regularly occurring requirement in (H)EMS. Our finding of a convincingly high success rate of 94% in trained hands encourages training and a timely performance of cricothyrotomy.

Benefits and harms of increased inspiratory oxygen concentrations.

PURPOSE OF REVIEW: The topic of perioperative hyperoxia remains controversial, with valid arguments on both the 'pro' and 'con' side. On the 'pro' side, the prevention of surgical site infections was a strong argument, leading to the recommendation of the use of hyperoxia in the guidelines of the Center for Disease Control and the WHO. On the 'con' side, the pathophysiology of hyperoxia has increasingly been acknowledged, in particular the pulmonary side effects and aggravation of ischaemia/reperfusion injuries. RECENT FINDINGS: Some 'pro' articles leading to the Center for Disease Control and WHO guidelines advocating perioperative hyperoxia have been retracted, and the recommendations were downgraded from 'strong' to 'conditional'. At the same time, evidence that supports a tailored, more restrictive use of oxygen, for example, in patients with myocardial infarction or following cardiac arrest, is accumulating. SUMMARY: The change in recommendation exemplifies that despite much work performed on the field of hyperoxia recently, evidence on either side of the argument remains weak. Outcome-based research is needed for reaching a definite recommendation.

Hemorrhage Treatment Adjuncts in a Helicopter Emergency Medical Service.

Hemorrhaging is the leading cause of preventable death after trauma. In our helicopter emergency medical service (HEMS), we introduced a bundle of 3 hemostatic adjuncts: 1) tourniquet, 2) hemostatic chitosan-based wound packings, and 3) tranexamic acid (TXA). The real-life frequency of applying these adjuncts in HEMS remains unclear. Therefore, we analyzed our electronic HEMS database regarding the use of these hemostatic adjuncts. We analyzed all subsequent dispatches of our HEMS "Lifeliner 1" within a searchable digital database (01.02.2013-22.05.2018). This HEMS operates 24/7, servicing ∼4.5 million inhabitants of the Netherlands. During the 75-month study period, we registered 15,759 dispatches, of which 8,658 were canceled, and 7,101 included on-site patient care, including 4,928 (69.4%) trauma cases. In total, we recorded 78 tourniquet applications (1.1% of patients), 104 hemostatic wound packings (1.5% of patients), and 1,379 cases with prehospital TXA administration (19.4% of patients). This difference in the use of hemostatics has several contributors, including a possible lack of awareness for tourniquets and procoagulant wound packing, a high proportion of blunt trauma with internal bleeding not accessible to tourniquet or wound packing, and a liberal use of TXA (eg, in patients with unproven hemorrhage). Besides creating awareness for those hemostatic adjuncts, the practical implications of our findings need further evaluation in future studies.

Postanesthesia care by remote monitoring of vital signs in surgical wards.

PURPOSE OF REVIEW: This narrative review summarizes recent insights into the role of remote monitoring of vital signs in the postoperative period in surgical wards. RECENT FINDINGS: Despite recent improvements in the safety of anesthesia and surgical procedures, postoperative complication rates are still unacceptably high. This is partly attributable to the intermittent provision of personal care to patients by nurses and ward physicians. Continuous remote monitoring of vital functions in the early postoperative period may reduce these complication rates. There are several medical-grade remote monitoring platforms available that integrate a biosensor signal with electronic patient records, enabling automated prediction or notification of patient deterioration. Most available platforms have technical limitations with respect to the accuracy of respiratory rate measurements. Of note, although the implementation of automated notifications of patient deterioration is associated with a reduced activation of acute response teams, the involvement of ward physicians in the early diagnosis and treatment of subtle changes in vital functions is increased. SUMMARY: Remote monitoring of vital signs in the surgical ward may contribute to prevention of severe complications and reduction in failure-to-rescue rates, although evidence for this association is still lacking. Anesthesiologists should contribute their knowledge and skills with respect to perioperative abnormalities in vital functions to improve patient safety during the postoperative period.

Early warning scores in the perioperative period: applications and clinical operating characteristics.

PURPOSE OF REVIEW: Early warnings scores are designed to detect clinical deterioration and promote intervention at the earliest possible moment. Although the ultimate effects on patient outcomes are unclear, early warning scores are now legally mandated in several countries. Here, we review the performance of early warning scores in surgical and perioperative populations. RECENT FINDINGS: Early warning scores can be used to screen for postoperative deterioration and surgical complications. We describe a framework to evaluate the balance between missed events and warning signals that are not followed by an adverse event (nonevents). In large surgical cohort studies, the missed event rates ranged between 19 and 69% and the nonevent rates ranged between 72 and 99% for 'optimal' threshold early warning sores. Recent investigations have shown that there may be a substantial discrepancy between the theoretical benefits shown in validation studies and the practical clinical implementation of early warning scores, which may partly explain the absence of measurable benefit from these systems. SUMMARY: Early warning scores may facilitate protocolized escalation of care for patients at risk of adverse events and can be used in surgical and postoperative patients, but high nonevent rates and practical implementation problems can restrict their usefulness.

Relationship between non-technical skills and technical performance during cardiopulmonary resuscitation: does stress have an influence?

BACKGROUND: Non-technical skills, such as task management, leadership, situational awareness, communication and decision-making refer to cognitive, behavioural and social skills that contribute to safe and efficient team performance. The importance of these skills during cardiopulmonary resuscitation (CPR) is increasingly emphasised. Nonetheless, the relationship between non-technical skills and technical performance is poorly understood. We hypothesise that non-technical skills become increasingly important under stressful conditions when individuals are distracted from their tasks, and investigated the relationship between non-technical and technical skills under control conditions and when external stressors are present. METHODS: In this simulator-based randomised cross-over study, 30 anaesthesiologists and anaesthesia residents from the VU University Medical Center, Amsterdam, the Netherlands, participated in two different CPR scenarios in random order. In one scenario, external stressors (radio noise and a distractive scripted family member) were added, while the other scenario without stressors served as control condition. Non-technical performance of the team leader and technical performance of the team were measured using the 'Anaesthetists' Non-technical Skill' score and a recently developed technical skills score. Analysis of variance and Pearson correlation coefficients were used for statistical analyses. RESULTS: Non-technical performance declined when external stressors were present (adjusted mean difference 3.9 points, 95% CI 2.4 to 5.5 points). A significant correlation between non-technical and technical performance scores was observed when external stressors were present (r=0.67, 95% CI 0.40 to 0.83, p<0.001), while no evidence for such a relationship was observed under control conditions (r=0.15, 95% CI -0.22 to 0.49, p=0.42). This was equally true for all individual domains of the non-technical performance score (task management, team working, situation awareness, decision-making). CONCLUSIONS: During CPR with external stressors, the team's technical performance is related to the non-technical skills of the team leader. This may have important implications for training of CPR teams.

The effect of perioperative insulin treatment on cardiodepression in mild adiposity in mice.

BACKGROUND: While most studies focus on cardiovascular morbidity following anesthesia and surgery in excessive obesity, it is unknown whether these intraoperative cardiovascular alterations also occur in milder forms of adiposity without type 2 diabetes and if insulin is a possible treatment to improve intraoperative myocardial performance. In this experimental study we investigated whether mild adiposity without metabolic alterations is already associated with cardiometabolic dysfunction during anesthesia, mechanical ventilation and surgery and whether these myocardial alterations can be neutralized by intraoperative insulin treatment. METHODS: Mice were fed a western (WD) or control diet (CD) for 4 weeks. After metabolic profiling, mice underwent general anesthesia, mechanical ventilation and surgery. Cardiac function was determined with echocardiography and left-ventricular pressure-volume analysis. Myocardial perfusion was determined with contrast-enhanced echocardiography. WD-fed mice were subsequently treated with insulin by hyperinsulinemic euglycemic clamping followed by the same measurements of cardiac function and perfusion. RESULTS: Western-type diet feeding led to a 13 % increase in bodyweight, (p < 0.0001) and increased adipose tissue mass, without metabolic alterations. Despite this mild phenotype, WD-fed mice had decreased systolic and diastolic function (end-systolic elastance was 2.0 ± 0.5 versus 4.1 ± 2.4 mmHg/µL, p = 0.01 and diastolic beta was 0.07 ± 0.03 versus 0.04 ± 0.01 mmHg/µL, p = 0.02) compared to CD-fed mice. Ventriculo-arterial coupling and myocardial perfusion were decreased by 48 % (p = 0.003) and 43 % (p = 0.03) respectively. Insulin treatment in WD-fed mice improved echo-derived systolic function (fractional shortening 42 ± 5 % to 46 ± 3, p = 0.05), likely due to decreased afterload, but there was no effect on load-independent measures of systolic function or myocardial perfusion. However, there was a trend towards improved diastolic function after insulin treatment (43 % improvement, p = 0.05) in WD-fed mice. CONCLUSIONS: Mild adiposity without metabolic alterations already affected cardiac function and perfusion during anesthesia, mechanical ventilation and surgery in mice. Intraoperative insulin may be beneficial to reduce afterload and enhance intraoperative ventricular relaxation, but not to improve ventricular contractility or myocardial perfusion.