AcumenTM hypotension prediction index guidance for prevention and treatment of hypotension in noncardiac surgery: a prospective, single-arm, multicenter trial.

BACKGROUND: Intraoperative hypotension is common during noncardiac surgery and is associated with postoperative myocardial infarction, acute kidney injury, stroke, and severe infection. The Hypotension Prediction Index software is an algorithm based on arterial waveform analysis that alerts clinicians of the patient's likelihood of experiencing a future hypotensive event, defined as mean arterial pressure < 65 mmHg for at least 1 min. METHODS: Two analyses included (1) a prospective, single-arm trial, with continuous blood pressure measurements from study monitors, compared to a historical comparison cohort. (2) A post hoc analysis of a subset of trial participants versus a propensity score-weighted contemporaneous comparison group, using external data from the Multicenter Perioperative Outcomes Group (MPOG). The trial included 485 subjects in 11 sites; 406 were in the final effectiveness analysis. The post hoc analysis included 457 trial participants and 15,796 comparison patients. Patients were eligible if aged 18 years or older, American Society of Anesthesiologists (ASA) physical status 3 or 4, and scheduled for moderate- to high-risk noncardiac surgery expected to last at least 3 h. MEASUREMENTS: minutes of mean arterial pressure (MAP) below 65 mmHg and area under MAP < 65 mmHg. RESULTS: Analysis 1: Trial subjects (n = 406) experienced a mean of 9 ± 13 min of MAP below 65 mmHg, compared with the MPOG historical control mean of 25 ± 41 min, a 65% reduction (p < 0.001). Subjects with at least one episode of hypotension (n = 293) had a mean of 12 ± 14 min of MAP below 65 mmHg compared with the MPOG historical control mean of 28 ± 43 min, a 58% reduction (p< 0.001). Analysis 2: In the post hoc inverse probability treatment weighting model, patients in the trial demonstrated a 35% reduction in minutes of hypotension compared to a contemporaneous comparison group [exponentiated coefficient: - 0.35 (95%CI - 0.43, - 0.27); p < 0.001]. CONCLUSIONS: The use of prediction software for blood pressure management was associated with a clinically meaningful reduction in the duration of intraoperative hypotension. Further studies must investigate whether predictive algorithms to prevent hypotension can reduce adverse outcomes. TRIAL REGISTRATION: Clinical trial number: NCT03805217. Registry URL: https://clinicaltrials.gov/ct2/show/NCT03805217 . Principal investigator: Xiaodong Bao, MD, PhD. Date of registration: January 15, 2019.

Anesthetic Management for Pulmonary Resection: Current Concepts and Improving Safety of Anesthesia.

Increasingly complex procedures are routinely performed using minimally invasive approaches, allowing cancers to be resected with short hospital stays, minimal postsurgical discomfort, and improved odds of cancer-free survival. Along with these changes, the focus of anesthetic management for lung resection surgery has expanded from the provision of ideal surgical conditions and safe intraoperative patient care to include preoperative patient training and optimization and postoperative pain management techniques that can impact pulmonary outcomes as well as patient lengths of stay.

Airway management and anesthesia for airway surgery: a narrative review.

OBJECTIVE: To discuss and summarize the literature for airway and anesthetic management tools the anesthesiologist can use for airway surgery to both successfully manage the patient's physiological needs and provide the surgeon the optimal surgical conditions with which to perform the surgery safely. BACKGROUND: The airway and anesthetic management of patients presenting for thoracic surgery poses the anesthesiologist with a unique set of challenges, but also a unique set of opportunities to artfully utilize and adapt a variety of management options that has developed over several decades of innovation. Sixty years ago, airway surgery was initially performed with the patient spontaneously breathing and providing anesthesia with halogenated agents and airway topicalization. As medicine entered the latter half of the twentieth century with its development of new airway devices and modern anesthetic agents, most airway surgeries could be safely performed under general anesthesia with secured airways. Today, with continued technological advancements in surgical techniques and an expanding population of challenging patients, the application of nonintubated anesthetic techniques and extracorporeal support is on the rise. METHODS: We conduct a narrative review of the literature on the history of airway and anesthetic management for thoracic surgery, the current management methods and evidence for each modality, and discuss future directions for the field. CONCLUSIONS: While the airway and anesthetic management for airway surgery is challenging, the anesthesiologist has a variety of options including cross-field ventilation, jet ventilation, nonintubated techniques, and extracorporeal support to safely care for the patient. Whichever methods are chosen for the patient and surgery, thoracic surgery remains uniquely positioned in its need for close sharing and collaboration of all airway and anesthetic management decisions between the anesthesiologist and the surgeon.

Effects of night surgery on postoperative mortality and morbidity: a multicentre cohort study.

BACKGROUND: Surgery at night (incision time 17:00 to 07:00 hours) may lead to increased postoperative mortality and morbidity. Mechanisms explaining this association remain unclear. METHODS: We conducted a multicentre retrospective cohort study of adult patients undergoing non-cardiac surgery with general anaesthesia at two major, competing tertiary care hospital networks. In primary analysis, we imputed missing data and determined whether exposure to night surgery affects 30-day mortality using a mixed-effects model with individual anaesthesia and surgical providers as random effects. Secondary outcomes were 30-day morbidity and the mediating effect of blood transfusion rates and provider handovers on the effect of night surgery on outcomes. We further tested for effect modification by surgical setting. RESULTS: Among 350 235 participants in the primary imputed cohort, the mortality rate was 0.9% (n=2804/322 327) after day and 3.4% (n=940/27 908) after night surgery. Night surgery was associated with an increased risk of mortality (ORadj 1.26, 95% CI 1.15 to 1.38, p<0.001). In secondary analyses, night surgery was associated with increased morbidity (ORadj 1.41, 95% CI 1.33 to 1.48, p<0.001). The proportion of patients receiving intraoperative blood transfusion and anaesthesia handovers were higher during night-time, mediating 9.4% (95% CI 4.7% to 14.2%, p<0.001) of the effect of night surgery on 30-day mortality and 8.4% (95% CI 6.7% to 10.1%, p<0.001) of its effect on morbidity. The primary association was modified by the surgical setting (p-for-interaction<0.001), towards a greater effect in patients undergoing ambulatory/same-day surgery (ORadj 1.81, 95% CI 1.39 to 2.35) compared with inpatients (ORadj 1.17, 95% CI 1.02 to 1.34). CONCLUSIONS: Night surgery was associated with an increased risk of postoperative mortality and morbidity. The effect was independent of case acuity and was mediated by potentially preventable factors: higher blood transfusion rates and more frequent provider handovers.

A Focused Transesophageal Echocardiography Protocol for Intraoperative Management During Orthotopic Liver Transplantation.

OBJECTIVE: The value of a simplified, focused intraoperative transesophageal echocardiography (TEE) protocol in patients undergoing liver transplantation (LT) is unknown. We sought to create and assess a 5-view LT TEE examination focused on 5 prespecified common causes of hypotension during LT. DESIGN: Retrospective cohort study. SETTING: Single-center tertiary academic hospital. PARTICIPANTS: All patients undergoing LT with TEE from January 2010 through May 2019. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: A 5-view LT TEE protocol adapted from a published rescue TEE protocol was assessed retrospectively in a cohort of 106 patients. The primary outcome was the frequency with which the protocol would have detected a composite of 5 prespecified causes of hypotension if the TEE exam had been limited to those views. To assess potential influence on intraoperative care, management changes associated with TEE images were extracted from the medical record. The prespecified diagnoses occurred 24 times; the LT TEE protocol would have detected 22 of 24 of these (92%, 95% confidence interval [CI]: 74%-98%). Intraoperative management changes occurred in 15 of 16 patients (94%) with 1 of the prespecified TEE findings, compared with 1 of 27 patients (3.7%) with TEE findings outside those diagnoses (p < 0.0001). CONCLUSIONS: In a retrospective cohort study, a simplified LT TEE protocol would have detected 92% of prespecified TEE findings. Management changes occurred in 94% of those patients, while changes rarely occurred in patients with other TEE findings. A focused LT TEE protocol may diagnose critical pathology adequately and guide management during LT when standard monitors are insufficient.

High-Frequency Jet Ventilation in the Prone Position to Facilitate Cryoablation of a Peridiaphragmatic Pulmonary Neoplasm: A Case Report.

Percutaneous cryoablation of pulmonary tumors at the posterior lung base is challenging due to diaphragmatic motion and the requirement for prone positioning. High-frequency jet ventilation allows oxygenation and ventilation with minimal diaphragmatic movement. In this case report, we describe the use of high-frequency jet ventilation in the prone position to facilitate the cryoablation of a peridiaphragmatic pulmonary neoplasm.

A Comprehensive Review of Transesophageal Echocardiography During Orthotopic Liver Transplantation.

Orthotopic liver transplantation (OLT) is characterized by significant hemodynamic disturbances and anesthetic challenges. Intraoperative transesophageal echocardiography (TEE) can be used to guide management during these procedures. This review examines the role of echocardiography during OLT, presents common TEE findings during each phase of OLT, and discusses the benefits demonstrated with TEE use and the safety of TEE in this patient population. Finally, the authors propose an algorithm for the safe use of TEE during OLT.

Cardiac Output Measurements Based on the Pulse Wave Transit Time and Thoracic Impedance Exhibit Limited Agreement With Thermodilution Method During Orthotopic Liver Transplantation.

BACKGROUND: Orthotopic liver transplantation (OLT) is characterized by significant intraoperative hemodynamic variability. Accurate and real-time cardiac output (CO) monitoring aids clinical decision making during OLT. The purpose of this study is to compare accuracy, precision, and trending ability of CO estimation obtained noninvasively using pulse wave transit time (estimated continuous cardiac output [esCCO; Nihon Kohden, Tokyo, Japan]) or thoracic bioimpedance (ICON; Osypka Medical GmbH, Berlin, Germany) to thermodilution cardiac output (TDCO) measured with a pulmonary artery catheter. METHODS: Nineteen patients undergoing OLT were enrolled. CO measurements were collected with esCCO, ICON, and thermodilution at 5 time points: (T1) pulmonary artery catheter insertion; (T2) surgical incision; (T3) portal reperfusion; (T4) hepatic arterial reperfusion; and (T5) abdominal closure. The results were analyzed with Bland-Altman plot, percentage error (the percentage of the difference between the CO estimated with the noninvasive monitoring device and CO measured with the thermodilution technique), 4-quadrant plot with concordance rate (the percentage of the total number of points in the I and III quadrant of the 4-quadrant plot), and concordance correlation coefficient (a measure of how well the pairs of observations deviate from the 45-degree line of perfect agreement). RESULTS: Although TDCO increased at T3-T5, both esCCO and ICON failed to track the changes of CO with sufficient accuracy and precision. The mean bias of esCCO and ICON compared to TDCO were -2.0 L/min (SD, ±2.7 L/min) and -3.3 L/min (SD, ±2.8 L/min), respectively. The percentage error was 69% for esCCO and 77% for ICON. The concordance correlation coefficient was 0.653 (95% confidence interval [CI], 0.283-0.853) for esCCO and 0.310 (95% CI, -0.167 to 0.669) for ICON. Nonetheless, esCCO and ICON exhibited reasonable trending ability of TDCO (concordance rate: 95% [95% CI, 88-100] and 100% [95% CI, 93-100]), respectively. The mean bias was correlated with systemic vascular resistance (SVR) and arterial elastance (Ea) for esCCO (SVR, r = 0.610, 95% CI, 0.216-0.833, P < .0001; Ea, r = 0.692, 95% CI, 0.347-0.872; P < .0001) and ICON (SVR, r = 0.573, 95% CI, 0.161-0.815, P < .0001; Ea, r = 0.612, 95% CI, 0.219-0.834, P < .0001). CONCLUSIONS: The noninvasive CO estimation with esCCO and ICON exhibited limited accuracy and precision, despite with reasonable trending ability, when compared to TDCO, during OLT. The inaccuracy of esCCO and ICON is especially large when SVR and Ea were decreased during the neohepatic phase. Further refinement of the technology is desirable before noninvasive techniques can replace TDCO during OLT.

Extended Motor Evoked Potentials Monitoring Helps Prevent Delayed Paraplegia After Aortic Surgery.

OBJECTIVE: Motor evoked potentials (MEPs) monitoring can promptly detect spinal cord ischemia (SCI) from aortic clamping during open thoracoabdominal aneurysm repair (OTAAR) with distal aortic perfusion (DAP) and thus help decrease the risk of immediate postoperative SCI (IP-SCI). However, neither stable MEPs during aortic clamp interval (ACI) nor absence of IP-SCI eliminate the possibility of delayed postoperative SCI (DP-SCI). We hypothesized that extension of MEPs monitoring beyond ACI can also help decrease the risk of DP-SCI. METHODS: We identified 150 consecutive patients at our institution between April 2005 and October 2014 who underwent OTAAR with DAP and MEPs monitoring and had no IP-SCI. Using logistic regression analysis, we studied the independent effect of extended MEPs monitoring on the risk of developing DP-SCI. We used a propensity score analysis to adjust for potential confounders, such as poorly controlled hypertension, previous aneurysm surgery, splenectomy, acute aortic dissection, aneurysm type, older age, and history of diabetes and smoking. RESULTS: From the 150 patients, 129 (86%) remained neurologically intact whereas 21 (14%) developed DP-SCI. Nineteen of these twenty-one patients (90%) had no extended monitoring. Fifty-seven of fifty-nine (97%) patients who benefited from extended monitoring had no DP-SCI (p = 0.003). Extended MEPs monitoring was independently associated with decreased risk of DP-SCI (odds ratio = 0.14; 95% confidence interval: 0.03, 0.65; p = 0.01). INTERPRETATION: MEPs detect the lowest systemic blood pressure that ensures appropriate spinal cord perfusion in the postoperative period. Thus, they inform the hemodynamic management of patients post-OTAAR, particularly in the absence of a reliable neurological exam.

Anesthetic drug development: Novel drugs and new approaches.

The ideal sedative-hypnotic drug would be a rapidly titratable intravenous agent with a high therapeutic index and minimal side effects. The current efforts to develop such agents are primarily focused on modifying the structures of existing drugs to improve their pharmacodynamic and pharmacokinetic properties. Drugs currently under development using this rational design approach include analogues of midazolam, propofol, and etomidate, such as remimazolam, PF0713, and cyclopropyl methoxycarbonyl-etomidate (MOC-etomidate), respectively. An alternative approach involves the rapid screening of large libraries of molecules for activity in structural or phenotypic assays that approximate anesthetic and target receptor interactions. Such high-throughput screening offers the potential for identifying completely novel classes of drugs. Anesthetic drug development is experiencing a resurgence of interest because there are new demands on our clinical practice that can be met, at least in part, with better agents. The goal of this review is to provide the reader with a glimpse of the novel anesthetic drugs and new developmental approaches that lie on the horizon.

The management and outcome of documented intraoperative heart rate-related electrocardiographic changes.

OBJECTIVES: The authors analyzed surgical cases in which electrocardiographic (ECG) signs of cardiac ischemia were noted to be precipitated by increases in heart rate (ie, heart rate-related ECG changes [REC]). The authors aimed to find REC incidence, specificity for coronary artery disease (CAD), and the outcome associated with different management strategies. DESIGN: A retrospective review. SETTING: A university hospital, tertiary care. PARTICIPANTS: Patients undergoing surgery under anesthesia. INTERVENTIONS: A chart review. MEASUREMENTS: The authors searched 158,252 anesthesia electronic records for comments noting REC (ie, ST-segment or T-wave changes). After excluding cases with potentially confounding conditions (eg, hypotension, hyperkalemia, and so on), 26 cases were analyzed. RESULTS: REC commonly was precipitated by anesthesia-related events (ie, intubation, extubation, and treatment of bradycardia). In 24 cases, REC was managed by prompt heart rate reduction using ß-blocker agents, opioids, and/or cardioversion in the addition to the removal of stimulus. Only 1 case had a copy of the ECG printed. Two cases were aborted, 1 was shortened and 23 proceeded without change. Postoperative troponin T levels were checked, and cardiology consultation was obtained in selected cases and led to further cardiac evaluation in 6 cases. Postoperative myocardial infarction developed in only 1 patient in whom the ECG changes were allowed to persist throughout the case. CONCLUSIONS: This incidence of reported REC was much lower than the previously reported incidence of ischemia-related ECG changes, suggesting that the largest proportion of events go unnoticed. In many patients, subsequent cardiology workup did not confirm the existence of clinically significant CAD.

Crisis resource management of the airway in a patient with Klippel-Feil syndrome, congenital deafness, and aortic dissection.

Klippel-Feil syndrome is a visually arresting deformity wherein severe restriction of cervical motion predicts a difficult airway. Even minor distraction of the neck risks cervical spine or neurologic injury, so regional techniques, awake fiberoptic intubation, or awake tracheostomy are recommended anesthetic approaches. We present a case of aortic dissection in a Klippel-Feil syndrome patient for whom congenital bilateral deafness, coupled with the urgency of the surgery, mitigated against the recommended first-choice techniques. Using anesthesia crisis resource management methods, a multi-member team rehearsed predefined roles and then managed the airway via inhaled induction of anesthesia, followed by flexible fiberoptic intubation.