CARDIOVASCULAR ENGINEERING Journal for Extracorporeal Circulation, Assist Devices,Transplantation and Artificial Organs
	Volume 5, 2000, No 4

Anaesthetic Considerations for Robotics
P. Kessler, S. Mierdl, V. Lischke, C. Byhahn, T. Aybek, S. Dogan, G. Wimmer-Greinecker, K. Westphal

Background: The introduction of new minimally invasive cardiac procedures has significant anaesthetic implications, in particular with regard to cannulation and monitoring. The aim of this study is to evaluate the special risks and benefits, as well as the practical application of computer enhanced totally endoscopic bypass grafting (TECAB) from the anaesthesiologist’s point of view.
Methods: Following institutional ethic committee approval 10 patients with isolated coronary single vessel disease undergoing TECAB procedures were included in the study. Because of specific cannulation/catheter systems (Port-Access) and the haemodynamic consequences of carbon dioxide (CO₂) insufflation TECAB procedures require specific anaesthetic monitoring techniques: transesophageal echocardiography (TEE), double lumen intubation for single lung ventilation, cannulation of both radial arteries, placement of pulmonary artery vent and coronary sinus catheters. The following time intervals were measured: anaesthetic preparation, length of cardiopulmonary bypass (CPB), and duration of cardioplegic arrest and single lung ventilation. At defined points in time a cine-loop of both ventricles was registered by TEE employing a mid short axis view. At the same time oxygenation parameters as well as electrocardiographic data and intrathoracic CO₂-pressure were obtained. Finally, wall motion analysis was done postoperatively.
Results: Anaesthetic preparation required 62 ± 23 min, single lung ventilation took 171 ± 34 min. With increasing duration of single lung ventilation, significant regional and global biventricular hypokinesis was detected. This was accompagnied by a decrease in PaO₂ und a marked increase in intrathoracic CO₂-pressure. These alterations disappeared after weaning from extracorporeal circulation and resumption of double lung ventilation. 
Conclusion: Compared to standard proceduress, TECAB is time consuming and requires excellent communication among anaesthesiologist, surgeon and perfusionist. An extended anaesthetic monitoring is recommended for TECAB procedures. In particular, TEE is necessary for early detection of impaired cardiac filling pressures and alterations in intraoperative biventricular myocardial function. These changes are probably caused by inadequate oxygenation during  single lung ventilation or by intrathoracic CO₂-insufflation. However, in our group, these alterations were only of minor clinical relevance. 

(CVE. 2000; 5 (4): 261-266)

Key words: cardiac anaesthesia, port access technique, totally endoscopic coronary artery bypass grafting, transesophageal  echocardiography, single lung ventilation, carbon dioxide insufflation

Paul Kessler, M.D.
Associate Professor
Clinics of Anaesthesiology, Intensive Care Medicine und Pain Therapy
Johann Wolfgang Goethe-University Frankfurt
Theodor-Stern-Kai 7
D-60590 Frankfurt
Germany
E-mail: P.Kessler@em.uni-frankfurt.de

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