Occurrence of Low Cardiac Index During Normotensive Periods in Cardiac Surgery: A Prospective Cohort Study Using Continuous Noninvasive Cardiac Output Monitoring.

BACKGROUND: Continuous cardiac output monitoring is not standard practice during cardiac surgery, even though patients are at substantial risk for systemic hypoperfusion. Thus, the frequency of low cardiac output during cardiac surgery is unknown. METHODS: We conducted a prospective cohort study at a tertiary medical center from July 2021 to November 2023. Eligible patients were ≥18 undergoing isolated coronary bypass (CAB) surgery with the use of cardiopulmonary bypass (CPB). Cardiac output indexed to body surface area (CI) was continuously recorded at 5-second intervals throughout surgery using a US Food and Drug Administration (FDA)-approved noninvasive monitor from the arterial blood pressure waveform. Mean arterial blood pressure (MAP) and central venous pressure (CVP) were also analyzed. Low CI was defined as <2 L/min/m2 and low MAP as <65 mm Hg. We calculated time with low CI for each patient for the entire surgery, pre-CPB and post-CPB periods, and the proportion of time with low CI and normal MAP. We used Pearson correlation to evaluate the relationship between CI and MAP and paired Wilcoxon rank sum tests to assess the difference in correlations of CI with MAP before and after CPB. RESULTS: In total, 101 patients were analyzed (age [standard deviation, SD] 64.8 [9.8] years, 25% female). Total intraoperative time (mean [SD]) with low CI was 86.4 (62) minutes, with 61.2 (42) minutes of low CI pre-CPB and 25.2 (31) minutes post-CPB. Total intraoperative time with low CI and normal MAP was 66.5 (56) minutes, representing mean (SD) 69% (23%) of the total time with low CI; 45.8 (38) minutes occurred pre-CPB and 20.6 (27) minutes occurred post-CPB. Overall, the correlation (mean [SD]) between CI and MAP was 0.33 (0.31), and the correlation was significantly higher pre-CPB (0.53 [0.32]) than post-CPB (0.29 [0.28], 95% confidence interval [CI] for difference [0.18-0.34], P < .001); however, there was substantial heterogeneity among participants in correlations of CI with MAP before and after CPB. Secondary analyses that accounted for CVP did not alter the correlation between CI and MAP. Exploratory analyses suggested duration of low CI (C <2 L/min/m2) was associated with increased risk of postoperative acute kidney injury (odds ratios [ORs] = 1.09; 95% CI; 1.01-1.13; P = .018). CONCLUSIONS: In a prospective cohort of patients undergoing CAB surgery, low CI was common even when blood pressure was normal. CI and MAP were correlated modestly. Correlation was higher before than after CPB with substantial heterogeneity among individuals. Future studies are needed to examine the independent relation of low CI to postoperative kidney injury and other adverse outcomes related to hypoperfusion.

Domains of Frailty Predict Loss of Independence in Older Adults After Noncardiac Surgery.

IMPORTANCE: Preoperative frailty has been consistently associated with death, severe complications, and loss of independence (LOI) after surgery. LOI is an important patient-centered outcome, but it is unclear which domains of frailty are most strongly associated with LOI. Such information would be important to target individual geriatric domains for optimization. OBJECTIVE: To assess whether impairment in individual domains of the Edmonton Frail Scale (EFS) can predict LOI in older adults after noncardiac surgery. DESIGN: Retrospective Cohort Study. SETTING: One Academic Hospital. PARTICIPANTS: Patients aged 65 or older who were living independently and evaluated with the EFS during a preoperative visit to the Center for Preoperative Optimization at the Johns Hopkins Hospital between June 2018 and January 2020. MAIN OUTCOME: LOI defined as discharge to increased level of care outside of the home with new mobility deficit or functional dependence. New mobility deficit and functional dependence were extracted from chart review of the standardized occupational therapy and physical therapy assessment performed before discharge. RESULTS: A total of 3497 patients were analyzed. Age (mean±SD) was 73.4±6.2 years, and 1579 (45.2%) were female. The median total EFS score was 3 (range 0-16), and 725/3497 (27%) were considered frail (EFS≥6). The frequencies of impairment in each EFS domain were functional performance (33.5% moderately impaired, 11% severely impaired), history of hospital readmission (42%), poor self-described health status (37%), and abnormal cognition (17.1% moderately impaired, 13.8% severely impaired). Overall, 235/3497 (6.7%) patients experienced LOI. Total EFS score was associated with LOI (odds ratio: 1.37, 95% CI, 1.30-1.45, P <0.001) in a model adjusted for age, sex, body mass index, American Society of Anesthesiologists rating, congestive heart failure, valvular heart disease, hypertension diagnosis, chronic lung disease, diabetes, renal failure, liver disease, weight loss, anemia, and depression. Using a nested log likelihood approach, the domains of functional performance, functional dependence, social support, health status, and urinary incontinence improved the base multivariable model. In cross-validation, total EFS improved the prediction of LOI with the final model achieving an area under the curve of 0.840. Functional performance was the single domain that most improved outcome prediction, but together with functional dependence, social support, and urinary incontinence, the model resulted in an area under the curve of 0.838. CONCLUSION AND RELEVANCE: Among domains measured by the EFS before a wide range of noncardiac surgeries in older adults, functional performance, functional dependence, social support, and urinary incontinence were independently associated with and improved the prediction of LOI. Clinical initiatives to mitigate LOI may consider screening with the EFS and targeting abnormalities within these domains.

Association Between Left Ventricular Relative Wall Thickness and Acute Kidney Injury After Noncardiac Surgery.

BACKGROUND: Acute kidney injury (AKI) after major noncardiac surgery is commonly attributed to cardiovascular dysfunction. Identifying novel associations between preoperative cardiovascular markers and kidney injury may guide risk stratification and perioperative intervention. Increased left ventricular relative wall thickness (RWT), routinely measured on echocardiography, is associated with myocardial dysfunction and long-term risk of heart failure in patients with preserved left ventricular ejection fraction (LVEF); however, its relationship to postoperative complications has not been studied. We evaluated the association between preoperative RWT and AKI in high-risk noncardiac surgical patients with preserved LVEF. METHODS: Patients ≥18 years of age having major noncardiac surgery (high-risk elective intra-abdominal or noncardiac intrathoracic surgery) between July 1, 2016, and June 30, 2018, who had transthoracic echocardiography in the previous 12 months were eligible. Patients with preoperative creatinine ≥2 mg/dL or reduced LVEF (<50%) were excluded. The association between RWT and AKI, defined as an increase in serum creatinine by 0.3 mg/dL from baseline within 48 hours or by 50% within 7 days after surgery, was assessed using multivariable logistic regression adjusted for preoperative covariates. An additional model adjusted for intraoperative covariates, which are strongly associated with AKI, especially hypotension. RWT was modeled continuously, associating the change in odds of AKI for each 0.1 increase in RWT. RESULTS: The study included 1041 patients (mean ± standard deviation [SD] age 62 ± 15 years; 59% female). A total of 145 subjects (13.9%) developed AKI within 7 days. For RWT quartiles 1 through 4, respectively, 20 of 262 (7.6%), 40 of 259 (15.4%), 39 of 263 (14.8%), and 46 of 257 (17.9%) developed AKI. Log-odds and proportion with AKI increased across the observed RWT values. After adjusting for confounders (demographics, American Society of Anesthesiologists [ASA] physical status, comorbidities, baseline creatinine, antihypertensive medications, and left ventricular mass index), each RWT increase of 0.1 was associated with an estimated 26% increased odds of developing AKI (odds ratio [OR]; 95% confidence interval [CI]) of 1.26 (1.09-1.46; P = .002). After adjusting for intraoperative covariates (length of surgery, presence of an arterial line, intraoperative hypotension, crystalloid administration, transfusion, and urine output), RWT remained independently associated with the odds of AKI (OR; 95% CI) of 1.28 (1.13-1.47; P = .001). Increased RWT was also independently associated with hospital length of stay and adjusted hazard ratio (HR [95% CI]) of 0.94 (0.89-0.99; P = .018). CONCLUSIONS: Left ventricular RWT is a novel cardiovascular factor associated with AKI within 7 days after high-risk noncardiac surgery among patients with preserved LVEF. Application of this commonly available measurement of risk stratification or perioperative intervention warrants further investigation.

Team Physiological Dynamics: A Critical Review.

OBJECTIVE: Review the use of physiological measurement in team settings and propose recommendations to improve the state of the science. BACKGROUND: New sensor and analytical capabilities enable exploration of relationships between team members' physiological dynamics. We conducted a review of physiological measures used in research on teams to understand (1) how these measures are theoretically and operationally related to team constructs and (2) what types of validity evidence exist for physiological measurement in team settings. METHOD: We identified 32 articles that investigated task-performing teams using physiological data. Articles were coded on several dimensions, including team characteristics. Study findings were categorized by relationships tested between team physiological dynamics (TPD) and team inputs, mediators/processes, outputs, or psychometric properties. RESULTS: TPD researchers overwhelmingly measure single physiological systems. Although there is research linking TPD to inputs and outputs, the research on processes is underdeveloped. CONCLUSION: We recommend several theoretical, methodological, and statistical themes to expand the growth of the TPD field. APPLICATION: Physiological measures, once established as reliable indicators of team functioning, might be used to diagnose suboptimal team states and cue interventions to ameliorate these states.

Mentoring Fellows in Adult Cardiothoracic Anesthesiology for Academic Practice in the Contemporary Era-Perspectives From Mentors Around the United States.

This special article presents perspectives on the mentoring of fellows for academic practice in adult cardiothoracic anesthesiology. A comprehensive mentoring model should address the areas of clinical care, educational expertise and exposure to scholarly activity. The additional value of educational exposure to patient safety, quality improvement and critical care medicine in this model is also explored.

Heparin-Induced Thrombocytopenia: A Review for Cardiac Anesthesiologists and Intensivists.

Patients undergoing cardiovascular surgery may be exposed to heparin before surgery, during cardiopulmonary bypass (CPB), or in the immediate postoperative period. For this reason, cardiovascular surgery patients are at increased risk for heparin-induced thrombocytopenia (HIT), occurring in 1 to 3% of patients. The diagnosis of HIT can be difficult, if based solely on the development of thrombocytopenia, because cardiac surgical patients have multiple reasons to be thrombocytopenic. Several clinical scoring systems have been developed to reduce unnecessary testing and better define the pretest probability of HIT, which we will review in detail with a diagnostic algorithm. In addition, we will cover the prevention and treatment HIT.

An analysis of methodologies that can be used to validate if a perioperative surgical home improves the patient-centeredness, evidence-based practice, quality, safety, and value of patient care.

Approximately 80 million inpatient and outpatient surgeries are performed annually in the United States. Widely variable and fragmented perioperative care exposes these surgical patients to lapses in expected standard of care, increases the chance for operational mistakes and accidents, results in unnecessary and potentially detrimental care, needlessly drives up costs, and adversely affects the patient healthcare experience. The American Society of Anesthesiologists and other stakeholders have proposed a more comprehensive model of perioperative care, the Perioperative Surgical Home (PSH), to improve current care of surgical patients and to meet the future demands of increased volume, quality standards, and patient-centered care. To justify implementation of this new healthcare delivery model to surgical colleagues, administrators, and patients and maintain the integrity of evidenced-based practice, the nascent PSH model must be rigorously evaluated. This special article proposes comparative effectiveness research aims or objectives and an optimal study design for the novel PSH model.

The Perioperative Surgical Home: how can it make the case so everyone wins?

BACKGROUND: Varied and fragmented care plans undertaken by different practitioners currently expose surgical patients to lapses in expected care, increase the chance for operational mistakes and accidents, and often result in unnecessary care. The Perioperative Surgical Home has thus been proposed by the American Society of Anesthesiologists and other stakeholders as an innovative, patient-centered, surgical continuity of care model that incorporates shared decision making. Topics central to the debate about an anesthesiology-based Perioperative Surgical Home include: holding the gains made in anesthesia-related patient safety; impacting surgical morbidity and mortality, including failure-to-rescue; achieving healthcare outcome metrics; assimilating comparative effectiveness research into the model; establishing necessary audit and data collection; a comparison with the hospitalist model of perioperative care; the perspective of the surgeon; the benefits of the Perioperative Surgical Home to the specialty of anesthesiology; and its associated healthcare economic advantages. DISCUSSION: Improving surgical morbidity and mortality mandates a more comprehensive and integrated approach to the management of surgical patients. In their expanded capacity as the surgical patient's "perioperativist," anesthesiologists can play a key role in compliance with broader set of process measures, thus becoming a more vital and valuable provider from the patient, administrator, and payer perspective. The robust perioperative databases created within the Perioperative Surgical Home present new opportunities for health services and population-level research. The Perioperative Surgical Home is not intended to replace the surgeon's patient care responsibility, but rather leverage the abilities of the entire perioperative care team in the service of the patient. To achieve this goal, it will be necessary to expand the core knowledge, skills, and experience of anesthesiologists. Anesthesiologists will need to view becoming perioperative physicians as an expansion of the specialty, rather than an abdication of their traditional intraoperative role. The Perioperative Surgical Home will need to create strategic added value for a health system and payers. This added value will strengthen the position of anesthesiologists as they navigate and negotiate in the face of finite, if not decreasing fiscal resources. SUMMARY: Broadening the anesthesiologist's scope of practice via the Perioperative Surgical Home may promote standardization and improve clinical outcomes and decrease resource utilization by providing greater patient-centered continuity of care throughout the preoperative, intraoperative, and postoperative periods.