The Anterior Mediastinal Mass-the Challenging Management of Hypoxemia Despite Peripheral Cannulation for ECMO

Anesthetic Risk with Large Mediastinal Masses: A Management Framework Based on a Systematic Review

BACKGROUND

Anesthesia administered to a patient with a large mediastinal mass engenders concern that it may precipitate catastrophic acute hemodynamic or respiratory decompensation. A review of the available evidence is needed to define the degree of risk, mechanisms, and preventative or reactive interventions to mitigate the risk.

METHODS

A systematic review of the PubMed database was conducted of studies involving adults with large mediastinal masses undergoing a procedure or anesthesia; all types of publications were included that provided data regarding risks, mechanisms, or techniques to address potential decompensation. This literature involves primarily case reports and small retrospective series; no quality assessment was deemed appropriate. Evidence was synthesized according to the consensus judgment of the writing panel.

RESULTS

Categories of low-, moderate-, high-, and very-high-risk emerged from review of the 72 included studies, based on the degree of symptoms, mass/chest ratio, and degree of airway and/or vascular compression. This streamlines the preparation needed-minimal for low-risk and more extensive for higher-risk. Assessment of the impact of physiologic derangement stemming from the anatomic compression in individual patients provides a framework for anesthetic management, and back-up plans should decompensation occur.

CONCLUSIONS

Despite limitations in the evidence inherent to a topic involving an uncommon but serious event, a framework was developed to streamline preparation for and management of patients with a large mediastinal mass requiring anesthesia in a rational manner.

Echocardiography for extracorporeal membrane oxygenation

Extracorporeal membrane oxygenation (ECMO) provides advanced cardiopulmonary life support for patients in cardiac and/or respiratory failure. Echocardiography provides essential diagnostic and anatomic information prior to ECMO initiation, allows for safe and efficient ECMO cannula positioning, guides optimization of flow, provides a modality for rapid troubleshooting and patient evaluation, and facilitates decision-making for eventual weaning of ECMO support. Currently, guidelines for echocardiographic assessment in this clinical context are lacking. In this review, we provide an overview of echocardiographic considerations for advanced imagers involved in the care of these complex patients. We focus predominately on new cannulas and complex cannulation techniques, including a special focus on double lumen cannulas and a section discussing indirect left ventricular venting. Echocardiography is tremendously valuable in providing optimal care in these challenging clinical situations. It is imperative for imaging physicians to understand the pertinent anatomic considerations, the often complicated physiological and hemodynamic context, and the limitations of the imaging modality.