Retrograde air embolization during routine radial artery catheter flushing in adult cardiac surgical patients: an ultrasound study.
BACKGROUND
Rapid flushing of radial artery catheters may result in retrograde embolization of air into the cerebral circulation. This study examined the incidence of central air embolization during and after flushing of an arterial pressure monitoring system.


METHODS
One hundred adult patients undergoing cardiac surgical procedures were enrolled in this study. Ten ml of saline and blood were withdrawn into a syringe in the arterial flushing-sampling pressure system and then readministered to the patient through a 20-gauge radial artery catheter over 3-12 s. The right carotid artery, left carotid artery, and aortic arch were visualized using ultrasound imaging techniques during three manual flushes of the system. The left and right common carotid arteries were examined for the presence of macrobubbles or microbubbles using a linear array ultrasound transducer. The aortic arch was imaged using transesophageal echocardiography to detect retrograde air emboli. The severity of air embolization was quantified using a modification of an established grading system.


RESULTS
A total of 298 ultrasound studies in 100 patients were recorded and analyzed after radial artery catheter flushing. Two aortic arch images were not obtained because of an inability to place the probe. Most clinicians (54%) returned flush solution to patients at near-maximal injection rates (2-3 ml per second). No air emboli (macrobubbles or microbubbles) were detected in the carotid arteries or aortic arch of any subject.


CONCLUSIONS
Retrograde air embolization is a rare event after routine radial artery catheter flushing in adult patients with stable hemodynamic conditions.
Department of Anesthesiology, Evanston Northwestern Healthcare, Northwestern University Feinberg School of Medicine, Evanston, Illinois 60201, USA. dgmurphy@core.com
Glenn S
GS
Murphy
Joseph W
JW
Szokol
Jesse H
JH
Marymont
Michael J
MJ
Avram
Jeffery S
JS
Vender
D000368:Aged; D001013:Aorta, Thoracic / Q000000981:diagnostic imaging; D001794:Blood Pressure / Q000502:physiology; D006348:Cardiac Surgical Procedures; D002340:Carotid Artery Diseases / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000209:etiology; D017536:Carotid Artery, Common / Q000000981:diagnostic imaging; D002406:Catheterization, Peripheral / Q000009:adverse effects*; D017548:Echocardiography, Transesophageal; D004618:Embolism, Air / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000209:etiology*; D005260:Female; D006801:Humans; D007431:Intraoperative Complications / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000209:etiology*; D008297:Male; D016343:Monitoring, Intraoperative; D010865:Pilot Projects; D011446:Prospective Studies; D017534:Radial Artery / Q000000981:diagnostic imaging