To the Editor
Dr. Lee A. Balaklaw raised a valid concern about positioning a catheter in the right atrium for the purposes of air aspiration since & September 1989 guidelines (APSF Newsletter 4:28, 1989) on central venous catheter safety noted that the catheter tip should not be placed in the heart.
Bunegin, et. al., found that maximal air aspiration from a single orificed catheter occurred when the tip was located in the superior vena cava (SVC) about 1.0 cm outside to the border of the right atrium (RA). On the other hand, they found that the optimal aspiration of air from a multiorificed catheter occurred when the tip was 0.5 cm into the RA. (1) Colley and Artru compared efficacy of air aspiration between the Cook mulfiorificed CVP catheter, the American Edwards 7F Swan-Ganz catheter (RA part) and the single orifice Sorenson CVP kit catheter. (2) They found the Cook multiorificed catheter to be superior in air aspiration characteristics than the other two catheters. Topographically, the proximal orifice of this multiorificed catheter was in the SVC (0.5-1.5 cm above the SVC-RA junction) and the distal part in the mid RA. From this data it appeared that we should not be constrained by the recommendations of the “Central Venous Catheter Safety Guidelines Task Force” when it comes to the question of using a central fine whose main purpose is for air aspiration.
Venous air embolism (VAE) can be a hazardous sequelae during neurosurgical procedures in the sitting position, or in any other surgical procedure where the heart is dependent to the surgical area and air can be entrained. A properly placed central venous fine is the hallmark for both the verification and treatment of VAE. (3)
We are conscious of the problems involved with catheter placement in the heart chambers and are in the process of testing a silicone rubber version of the Cook multiorificed air aspiration catheter. We believe that the lack of rigidity of silicone rubber would minimize the penetration of the heart chambers seen with the stiff plastic material used in the catheter manufacturing process.
Maurice S. Albin, M.D., M.Sc. (Anes.) Leonid Bunegin, B.S. Rosemary Hickey, M.D. Tod Sloan, M.D., Ph.D.
The Neuroanesthesia Service, Department of Anesthesiology, University of Texas Health Science Center, San Antonio, TX.
- Bunegin L, Albin NE, Helsel PE, Hoffman A, Hung TK: Positioning the right atrial catheter: a model for appraisal, Anesthesiology 55:343-358, 198 1.
- Colley PS, Artru AA: Bunegin-Albin catheter improves air retrieval and resuscitation from lethal venous air embolism in dogs. Anesth Analg 66:991-994, 1987.
- Albin MS, Carroll RG, Maroon JC: Clinical considerations concerning detection of venous air embolism. Neurosurgery 3:3W384,1978.