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.

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.

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.