Citations

Background: Venous air embolism (VAE) is a potentially catastrophic complication during neurosurgical procedures, particularly in the sitting position. As practices vary widely, we conducted a survey to describe the global practice patterns for intraoperative detection and management of VAE. Methods: Following institutional review board (IRB) approval, we conducted a cross-sectional study using a 48-question online survey that was distributed via a snowball sampling approach, initially to the Society of Neuroscience in Anesthesiology and Critical Care (SNACC) community and subsequently to international collaborators. Descriptive statistics summarized responses, and proportional comparisons between high-income and low- and middle-income country respondents were assessed using a χ 2 or the Fisher exact tests, as appropriate. Results: Of 307 responses, 297 were analyzed, representing 40 countries. Survey response rate was 25% among SNACC members. End-tidal carbon dioxide (EtCO 2 ) monitoring was the most frequently reported VAE monitoring modality, particularly for sitting craniotomies. Common barriers to implementing advanced monitoring included limited equipment availability and a lack of a transesophageal echocardiography (TEE) specialist. Decision-making for cases at VAE risk relied on team consensus (62%), review articles and primary literature (48%), and institutional protocols (42%). Among respondents, 89% expressed interest in consensus guidelines for VAE management. Conclusions: There is substantial global variability in both the preparation for and management of VAE during neurosurgical procedures. EtCO 2 is the preferred monitoring approach in routine practice, as resource limitations prevent the broader adoption of more sensitive techniques, such as TEE. The high interest in consensus guidelines underscores an opportunity for professional societies to standardize approaches and improve patient safety.

Mortality rates from pulmonary embolism (PE) remain significant, highlighting the need for alternative treatment strategies beyond traditional anticoagulation. Percutaneous interventions, including mechanical thrombectomy and catheter-directed thrombolysis, are emerging as promising options. Given the complex pathophysiology and unique risk profiles of these patients, meticulous multidisciplinary planning is essential. Anesthesiologists play a central role in coordinating care and managing perioperative risks to improve outcomes. This article provides insights into best safety practices and shares experiences from a leading quaternary center. It offers guidance for anesthesia providers to proactively engage in comprehensive risk stratification, participate in multidisciplinary discussions, and support robust contingency planning for managing PE patients undergoing percutaneous interventions in non-operating room anesthesia settings.

BACKGROUND AND OBJECTIVES: Venous air embolism (VAE) can cause significant morbidity and mortality. Prevention and management of VAE include cessation of air entrainment, positioning changes, and hemodynamic support. The degree to which position change and cardiac output (CO) moderate resolution of intracardiac air has not been rigorously studied using contemporary transesophageal echocardiography (TEE). METHODS: This observational cohort-type study aimed to identify the effect of supine vs sitting positioning on the movement and resolution of intracardiac air. In 20 patients undergoing seated neurosurgery, central venous air aspiration catheters were placed through the median basilic vein. TEE was used to estimate the time required for clearance of agitated microbubbles from the right atrium and ventricle in both the supine and sitting position. Estimates of CO were also obtained echocardiographically in each position. RESULTS: Average clearance time was faster in the sitting vs the supine position with no significant difference in CO. A negative correlation between CO and right atrial clearance time across all patients was demonstrated with a Pearson coefficient of −0.4 (95% CI −0.07, −0.65) with P = .02. CONCLUSION: During VAE, both patient position and CO can significantly affect how bubbles move through intracardiac chambers. However, augmenting CO during VAE may be clinically more feasible, efficient, and productive than changing positioning—especially during crises unless the changing in position is intended to halt the entrainment of air. Further TEE studies of intravascular air movement affected by other position changes (lateral, reverse Trendelenburg) and vasopressors should be considered.

Pulmonary embolism (PE) embodies a large healthcare burden globally and is the third leading cause of morbidity and mortality worldwide. Submassive (intermediate-risk) PE accounts for 40% of this burden. However, the optimal treatment pathway for this population remains complex and ill-defined. Catheter-directed interventions (CDIs) have shown promise in directly impacting morbidity and mortality while demonstrating a favorable success rate, safety profile, and decreased length of stay (LOS) in the intensive care unit and hospital. This retrospective review included 22 patients (50% female) with submassive PE who underwent mechanical thrombectomy (MT). A total of 45% had a contraindication to thrombolytics, the mean pulmonary embolism severity index was 127, 36% had saddle PE, the average decrease in mean pulmonary artery pressure (PAP) was 7.2 mmHg following MT, the average LOS was 6.9 days, the 30-day mortality rate was 9%, the major adverse event (MAE) rate was 9%, and the readmission rate was 13.6%. A total of 82% had successful removal of thrombus during MT with no major bleeding complications, intracranial hemorrhage events, or device-related deaths. Acknowledging the limitation of our small sample size, our data indicate that MT in the intermediate-high-risk submassive pulmonary embolism (PE) cohort resulted in a decreased hospital length of stay (LOS) and in-hospital mortality compared to standard anticoagulation therapy alone.

Perioperative cardiac arrest (POCA) is a catastrophic complication that requires immediate recognition and correction of the underlying cause to improve patient outcomes. While the hypoxia, hypovolemia, hydrogen ions (acidosis), hypo-/hyperkalemia, and hypothermia (Hs) and toxins, tamponade (cardiac), tension pneumothorax, thrombosis (pulmonary), and thrombosis (coronary) (Ts) mnemonic is a valuable tool for rapid differential diagnosis, it does not cover all possible causes leading to POCA. To address this limitation, we propose using the preload-contractility-afterload-rate and rhythm (PCARR) construct to categorize POCA, which is comprehensive, systemic, and physiologically logical. We provide evidence for each component in the PCARR construct and emphasize that it complements the Hs and Ts mnemonic rather than replacing it. Furthermore, we discuss the significance of utilizing monitored variables such as electrocardiography, pulse oxygen saturation, end-tidal carbon dioxide, and blood pressure to identify clues to the underlying cause of POCA. To aid in investigating POCA causes, we suggest the Anesthetic care, Surgery, Echocardiography, Relevant Check and History (A-SERCH) list of actions. We recommend combining the Hs and Ts mnemonic, the PCARR construct, monitoring, and the A-SERCH list of actions in a rational manner to investigate POCA causes. These proposals require real-world testing to assess their feasibility.

Abstract Purpose A human cadaveric model combining standard lung protective mechanical ventilation and modified cardiac bypass techniques was developed to allow investigation into automated modes of detection of venous air emboli (VAE) prior to in vivo human or animal investigations. Methods In this study, in order to create an artificial cardiopulmonary circuit in a cadaver that could mimic VAE physiology, the direction of flow was reversed from conventional cardiac bypass. Saline was circulated in isolation through the heart and lungs as opposed to the peripheral organs by placing the venous cannula into the aorta and the arterial cannula into the inferior vena cava with selective ligation of other vessels. Results Mechanical ventilation and this reversed cardiac bypass scheme allowed preliminary detection of VAE independently but not in concert in our current simulation scheme due to pulmonary edema in the cadaver. A limited dissection approach was used initially followed by a radical exposure of the great vessels, and both proved feasible in terms of air signal detection. We used electrical impendence as a preliminary tool to validate detection in this cadaveric model however we theorize that it would work for echocardiographic, intravenous ultrasound or other novel modalities as well. Conclusion A cadaveric model allows monitoring technology development with reduced use of animal and conventional human testing.