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J Thorac Cardiovasc Surg 1994;107:1531-1532
© 1994 Mosby, Inc.

LETTERS TO THE EDITOR

Facilitation of peripheral arterial access during cardiopulmonary bypass with an audio-guided Doppler ultrasound vascular access device

Department of Anesthesiology
Division of Cardiothoracic Anesthesiology^a

To the Editor:

Placement of an intraaortic balloon pump (IABP) may be required before separation from cardiopulmonary bypass (CPB) in certain patients with extensive myocardial injury. Unless access is obtained before the start of CPB, it may be difficult to locate the peripheral arterial access site because of absence of a palpable pulse. We report the use of an audio-guided Doppler ultrasound vascular access device for cannulating the femoral artery during CPB, after failure of traditional "blind" attempts at locating the access site.

An 81-year-old woman with a history of diffuse coronary artery disease, hypertension, and peripheral vascular disease underwent coronary arterial bypass grafting for unstable angina. On completion of the surgical repair, initial separation from CPB could not be successfully achieved because of poor myocardial performance. Therefore, CPB was reinstituted to allow additional reperfusion time, maximize inotropic support, and consider the placement of an IABP. After return to CPB with the subsequent loss of cardiac ejection, no peripheral pulses could be felt in either femoral artery. Despite multiple blind passes at a variety of periinguinal sites with an 18-gauge cannulating needle, no arterial flow was found and further attempts were suspended for fear of increased local injury and bleeding at the access sites.

An audio-guided ultrasound vascular access device exists for location and cannulation of peripheral vessels (Smartneedle; Peripheral Systems Group, Mountain View, Calif.), consisting of a miniaturized 20-gauge Doppler transducer inserted within an 18-gauge cannulation needle. When attached to an external amplifier, the device produces audio signals of distinct amplitude and frequency capable of differentiating arterial and venous blood flow patterns. It has been used successfully in a cohort of obese or coagulopathic patients for accessing the central venous circulation. ¹ Because this device depends solely on the detection of blood flow, irrespective of pulsatility, we thought it might be useful in this situation. After subcutaneous placement of a saline-flushed needle, the transducer was carefully fanned through the subcutaneous tissue to identify arterial flow. On the second pass, a distinct, high-pitched, continuous arterial audio signal was noted. With the transducer focused for maximal audio amplitude, the needle was advanced and arterial puncture readily achieved. After removal of the transducer from within the needle, a Seldinger wire technique was used to introduce an arterial catheter for IABP placement. Separation from CPB proceeded uneventfully.

Although the prophylactic placement of an arterial catheter before the commencement of CPB is warranted in potential IABP candidates, not all patients can be readily identified before bypass. The absence of a peripheral pulse makes location and cannulation of the femoral artery difficult, if not impossible, in some patients (e.g., obese patients). Although audio- and video-based Doppler ultrasonic devices have been used as adjuncts to arterial or venous cannulation in various sites, we know of no previous use of this particular device during nonpulsatile CPB. The potential for rapid localization of the peripheral artery, with a decreased number of passes of a large-bore needle, make the use of this device an attractive alternative to traditional "blind" cannulation techniques. Although differentiation of arterial and venous signals may be more difficult in the absence of vessel pulsatility, careful attention to both the amplitude and frequency of the detected signal will generally discriminate between artery and vein.

References

1. Gilbert TB, Seneff M. Facilitation of right internal jugular central venous cannulation using an audio-guided ultrasonic vascular access device. Abstracts of the Society of Cardiovascular Anesthesiologists, Fifteenth Annual Meeting, 1993:274.
   

This Article Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Add to Personal Folders Download to citation manager Author home page(s): Alejandro J. Sequeira Permission Requests Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Gilbert, T. B. Articles by Nisonson, A. B. Search for Related Content PubMed PubMed Citation Articles by Gilbert, T. B. Articles by Nisonson, A. B.