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A Simple Method of Flushing Arterial Catheters
A Simple Method of Flushing Arterial Catheters I?. A. Adam, M.D. ABSTRACT A method for the continuous flushing of arterial catheters used in arterial pressure monitoring is described. This procedure has proved more satisfactory than the intermittent flushing technique in preventing the formation of clot in the arterial cannula, thereby allowing continual blood pressure monitoring. The technique is based on the constant infusion of heparinized saline solution which is forced through the cannula by a pressure blood pump. A flow rate regulated to 10 to 20 drops per minute does not affect the accuracy of the pressure-monitoringequipment.
A
n indwelling arterial catheter used for continuous monitoring of blood pressure requires frequent flushing to keep the channel open. Intermittent manual flushing is unsatisfactory because of the danger of dislodging small emboli, the threat of bacterial contamination, and the possibility of using an undesirable amount of fluid. For these reasons, an ingenious method of continuously flushing arterial catheters has been employed [ 11. Further simplification of this principle, using common, easily available components, has served us well both experimentally and clinically in adults. DESCRIPTION OF COMPONENTS
The components of the catheter-flushing system, shown in the Figure, are the following:
A. B. C. D.
Any size arterial needle or catheter Any available intravenous extension set Two three-way stopcocks (type with one male and two female ends). One three-way stopcock with one female and two male ends+ E. One four-way stopcock (same as that used in the Fenwal central venous pressure set)t F. Sterile compressible plastic bag (of same type as blood container)? G. Reservoir compression device (common pressure device used to pump blood into patients)t and screw clamp for tubing. From the Thoracic Surgery Section, Surgical Service, Veterans Administration Hospital, Memphis, Tenn., and the Department of Thoracic Surgery, University of Tennessee College of Medicine, Memphis, Tenn. Accepted for publication March 13, 1970. OBecton, Didtinson, and Co., Rutherford, N.J. tFenwal Laboratories, Morton Grove, Ill.
VOL. 11, NO.
I,
JANUARY,
1971
61
ASLAM
liii : ;
Device used f o r flushing arterial catheters: 1, three-way stopcock; 2, intravenous extension set; 3, four-way stopcock (central venous pressure set, Fenwal); 4, threeway stopcock (double Luer-Lok); 5, arterial catheter; 6, regular three-way stopcock (two female ends); 7 , screw clamp; 8, sterile compressible plastic bag with reservoir compression device (blood pump). ASSEMBLY OF COMPONENTS The sterile compressible plastic bag is carefully filled with heparinized saline solution in such a way that all the air bubbles are flushed out. The fourway stopcock is then inserted to connect the transducer system and the indwelling arterial catheter. The heparinized saline solution is fed into the four-way stopcock through a blood-administration drip set. The structure of the four-way stopcock makes it necessary to use two additional three-way stopcocks for connecting it with the flushing solution and arterial catheter. T h e type with one male end and two female ends is used for connecticg with the flushing solution, and the type with two male ends is used for connecting with the arterial catheter. The screw clamp provided is used to occlude completely the plastic tubing of the drip set containing flushing solution. Pressure to about 250 mm. Hg is applied to the compressible plastic bag. The screw clamp is then slowly opened so that a very few drops of saline solution will drip into the drip chamber. If the flow is regulated to a small number of drops, about 10 to 20 per minute, the pressure recording is unaffected. The exact number of drops will vary depending on the 62
THE ANNALS OF THORACIC SURGERY
NOTE:
Simple Method of Flushing Arterial Catheters
size of the arterial catheter and the structure of the drip set. This can be shown easily using any pressure-simulating device. COMMENT
This system may also be used in cardiac catheterization to keep the catheter from becoming plugged with clots. T h e only precaution needed is to secure the screw clamp on the pressure-infusion set carefully so that it will not be inadvertently loosened, with the resulting rapid arterial infusion into the patient of heparinized saline solution. Securing the screw clamp with adhesive tape or using a smaller-sized plastic bag with a small volume of flushing fluid will decrease or eliminate this problem. REFERENCE 1. Johnson, D. G., and Ito, Y.
Continuous flush of arterial pressure-recording catheters: A safe and inexpensive system. J . Thorac. Cardiovasc. Surg. 57:675, 1969.
VOL. 11, NO.
1,
JANUARY,
1971
63
A
n indwelling arterial catheter used for continuous monitoring of blood pressure requires frequent flushing to keep the channel open. Intermittent manual flushing is unsatisfactory because of the danger of dislodging small emboli, the threat of bacterial contamination, and the possibility of using an undesirable amount of fluid. For these reasons, an ingenious method of continuously flushing arterial catheters has been employed [ 11. Further simplification of this principle, using common, easily available components, has served us well both experimentally and clinically in adults. DESCRIPTION OF COMPONENTS
The components of the catheter-flushing system, shown in the Figure, are the following:
A. B. C. D.
Any size arterial needle or catheter Any available intravenous extension set Two three-way stopcocks (type with one male and two female ends). One three-way stopcock with one female and two male ends+ E. One four-way stopcock (same as that used in the Fenwal central venous pressure set)t F. Sterile compressible plastic bag (of same type as blood container)? G. Reservoir compression device (common pressure device used to pump blood into patients)t and screw clamp for tubing. From the Thoracic Surgery Section, Surgical Service, Veterans Administration Hospital, Memphis, Tenn., and the Department of Thoracic Surgery, University of Tennessee College of Medicine, Memphis, Tenn. Accepted for publication March 13, 1970. OBecton, Didtinson, and Co., Rutherford, N.J. tFenwal Laboratories, Morton Grove, Ill.
VOL. 11, NO.
I,
JANUARY,
1971
61
ASLAM
liii : ;
Device used f o r flushing arterial catheters: 1, three-way stopcock; 2, intravenous extension set; 3, four-way stopcock (central venous pressure set, Fenwal); 4, threeway stopcock (double Luer-Lok); 5, arterial catheter; 6, regular three-way stopcock (two female ends); 7 , screw clamp; 8, sterile compressible plastic bag with reservoir compression device (blood pump). ASSEMBLY OF COMPONENTS The sterile compressible plastic bag is carefully filled with heparinized saline solution in such a way that all the air bubbles are flushed out. The fourway stopcock is then inserted to connect the transducer system and the indwelling arterial catheter. The heparinized saline solution is fed into the four-way stopcock through a blood-administration drip set. The structure of the four-way stopcock makes it necessary to use two additional three-way stopcocks for connecting it with the flushing solution and arterial catheter. T h e type with one male end and two female ends is used for connecticg with the flushing solution, and the type with two male ends is used for connecting with the arterial catheter. The screw clamp provided is used to occlude completely the plastic tubing of the drip set containing flushing solution. Pressure to about 250 mm. Hg is applied to the compressible plastic bag. The screw clamp is then slowly opened so that a very few drops of saline solution will drip into the drip chamber. If the flow is regulated to a small number of drops, about 10 to 20 per minute, the pressure recording is unaffected. The exact number of drops will vary depending on the 62
THE ANNALS OF THORACIC SURGERY
NOTE:
Simple Method of Flushing Arterial Catheters
size of the arterial catheter and the structure of the drip set. This can be shown easily using any pressure-simulating device. COMMENT
This system may also be used in cardiac catheterization to keep the catheter from becoming plugged with clots. T h e only precaution needed is to secure the screw clamp on the pressure-infusion set carefully so that it will not be inadvertently loosened, with the resulting rapid arterial infusion into the patient of heparinized saline solution. Securing the screw clamp with adhesive tape or using a smaller-sized plastic bag with a small volume of flushing fluid will decrease or eliminate this problem. REFERENCE 1. Johnson, D. G., and Ito, Y.
Continuous flush of arterial pressure-recording catheters: A safe and inexpensive system. J . Thorac. Cardiovasc. Surg. 57:675, 1969.
VOL. 11, NO.
1,
JANUARY,
1971
63