The establishment of perioperative transesophageal echocardiography (TEE) services requires clinicians with adequate clinical training, TEE machines and probes with appropriate software, a reporting and archiving process, and personnel who set up and maintain the equipment. Anesthesiology departments provide such services if there are a sufficient number of TEE-certified anesthesiologists in the hospital. The convenience of their continual presence in the operating room suite, combined with their understanding of operating room procedures and cardiac surgical needs, make anesthesiologists the logical choice to provide these services. Hospitals that lack anesthesiologists credentialed for perioperative TEE depend upon the clinical expertise of cardiologists who work in concert with the echocardiography laboratory. The department that provides the service is responsible for securing the necessary capital to purchase and maintain the equipment, archive the studies, generate a report, and maintain a continuous quality improvement (CQI) process for both the equipment and the clinicians providing the service. The service also benefits from having skilled technical personnel to maintain and operate equipment. Finally, clinicians should understand the unique billing and reimbursement processes associated with this distinct service, which differ from traditional anesthesiology billing and reimbursement process. Although many details pertinent to the service are institutionally dependent, this chapter provides general guidelines that may be implemented for most perioperative TEE services.
EQUIPMENT AND PROBE MAINTENANCE
Today's modern TEE probe maintains the original concept introduced by Hisanaga in 19771 as a modified gastroscope with an ultrasound transducer mounted on the tip. Typically, these latex-free probes are 80 to 100 cm long with a shaft diameter of 10 mm and a tip width measuring 12 to 14 mm. The three-dimensional (3D) probes are approximately 1 mm wider at the tip than two-dimensional (2D) probes. Newer 3D probes are approximately 1 mm wider at the tip than 2D probes. Rotary dials in the handheld housing control a series of cables sealed within the shaft that allow flexion, extension, and lateral flexion of the tip. Range of motion of the tip varies among manufacturers, but is approximately 60 degrees in-line flexion and extension and 60 degrees lateral flexion. Controls on the housing electronically steer the ultrasound transducer within the probe, providing full 180-degree rotation of the ultrasound beam.
A grounded shield covers all active circuits distal to the control housing, making electrical injury improbable unless the outer layer of the shaft is cracked. However, the probe should always be disconnected prior to external defibrillation, as minor defects in the covering could allow secondary arcing, potentially causing a burn injury to the tissue surrounding the probe. TEE probes inserted and positioned in the patient but not used for extended periods, such as during cardiopulmonary bypass, should be disconnected from the TEE machine. This practice prevents thermal injury or interaction with electrosurgical units. Electrical integrity of the TEE probe should be tested by a qualified technician as preventive maintenance and performed according to the ...