Display Settings:


Send to:

Choose Destination
Artif Organs. 2012 Jun;36(6):525-9. doi: 10.1111/j.1525-1594.2011.01415.x. Epub 2012 Feb 23.

A high blood level in the air trap reduces microemboli during hemodialysis.

Author information

  • 1Department of Internal Medicine, Skellefteå County Hospital, Skellefteå Institute of General Health and Medicine, Department of Medicine, Norrland University Hospital Institute of Technology, University of Umeå Department of Nephrology, Norrland University Hospital, Umeå, Sweden.


Previous studies have demonstrated the presence of air microemboli in the dialysis circuit and in the venous circulation of the patients during hemodialysis. In vitro studies indicate that a high blood level in the venous air trap reduces the extent of microbubble formation. The purpose of this study was to examine whether air microbubbles can be detected in the patient's access and if so, whether the degree of microbubble formation can be altered by changing the blood level in the venous air trap. This was a randomized, double-blinded, interventional study of 20 chronic hemodialysis patients. The patients were assigned to hemodialysis with either an elevated or a low blood level in the air trap. The investigator and the patient were blinded to the settings. The numbers of microbubbles were measured at the site of the arteriovenous (AV) access for 2 min with the aid of an ultrasonic Doppler device. The blood level in the air trap was then altered to the opposite setting and a new measurement was carried out after an equilibration period of 30 min. Median (range) for the number of microbubbles measured with the high air trap level and the low air trap level in AV access was 2.5 (0-80) compared with 17.5 (0-77), respectively (P = 0.044). The degree of microbubble formation in hemodialysis patients with AV access was reduced significantly if the blood level in the air trap was kept high. The exposure of potentially harmful air microbubbles was thereby significantly reduced. This measure can be performed with no additional healthcare cost.

© 2012, Copyright the Authors. Artificial Organs © 2012, International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

[PubMed - indexed for MEDLINE]
PubMed Commons home

PubMed Commons

How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for Blackwell Publishing
    Loading ...
    Write to the Help Desk