I Hate Dialysis Message Board

Dialysis Discussion => Dialysis: General Discussion => Topic started by: BigSky on October 25, 2010, 02:11:05 PM

Title: Maximum pressures before hemolysis occurs?
Post by: BigSky on October 25, 2010, 02:11:05 PM

Looking for some information or studies.

Does anyone know what the maximum venous pressure can be on dialysis before blood cells are hemolyzed?

Title: Re: Maximum pressures before hemolysis occurs?
Post by: cloud393 on October 25, 2010, 08:30:11 PM

I'm on nxstage and was told not to let it go over 250.

Title: Re: Maximum pressures before hemolysis occurs?
Post by: greg10 on October 25, 2010, 09:45:22 PM

Hemolysis during dialysis can be attributed to other factors such as hypotonic dialysate, choloramine levels, semioccluded/ defective tubing/dialyzer ( http://www.nature.com/ki/journal/v57/n4/full/4491507a.html ) rather than pump pressure, but here are the numbers:

"Therefore, a conservative approach to quality care for hemodialysis patients would be to keep the prepump arterial pressure less negative than -260 mmHg. This would ensure an adequate delivery of blood to the dialyzer and decrease the potential of hemolysis due to shear stress or negative pressure.

Risks associated with excessive negative pressure as monitored by the prepump arterial pressure monitor device are:

1. hemolysis due to excessive negative pressure and shearing of the blood cells;
.............

Risks as a result of excessive (venous) pressure, defined in the ANNA Core Curriculum as greater than 400 mmHg (Keen et al., 1995, p. 225), at the post-pump arterial pressure monitor are:

1. hemolysis due to excessive pressure and shearing of the blood cells; and..... "

http://findarticles.com/p/articles/mi_m0ICF/is_1_28/ai_n18613043/pg_3/?tag=content;col1

Title: Re: Maximum pressures before hemolysis occurs?
Post by: BigSky on October 26, 2010, 04:56:10 PM

Quote from: greg10 on October 25, 2010, 09:45:22 PM

Risks as a result of excessive (venous) pressure, defined in the ANNA Core Curriculum as greater than 400 mmHg (Keen et al., 1995, p. 225), at the post-pump arterial pressure monitor are:

1. hemolysis due to excessive pressure and shearing of the blood cells; and..... "

http://findarticles.com/p/articles/mi_m0ICF/is_1_28/ai_n18613043/pg_3/?tag=content;col1

I was wondering how  do you know that is about venous pressure?  Its under the arterial pressure section.

Title: Re: Maximum pressures before hemolysis occurs?
Post by: greg10 on October 26, 2010, 05:02:51 PM

Quote from: BigSky on October 26, 2010, 04:56:10 PM

Quote from: greg10 on October 25, 2010, 09:45:22 PM

Risks as a result of excessive (venous) pressure, defined in the ANNA Core Curriculum as greater than 400 mmHg (Keen et al., 1995, p. 225), at the post-pump arterial pressure monitor are:

1. hemolysis due to excessive pressure and shearing of the blood cells; and..... "

http://findarticles.com/p/articles/mi_m0ICF/is_1_28/ai_n18613043/pg_3/?tag=content;col1

I was wondering how  do you know that is about venous pressure?  Its under the arterial pressure section.

The number is positive, while the arterial pressure is expressed in a negative number, at least that is the way I read it.  From what I read and taught at NxStage, the arterial pressure reading has no meaning other than relative to the venous pressure. 

BTW, I am newbie, I don't know for certain what I am talking about and that is in my signature as well.  :)

Title: Re: Maximum pressures before hemolysis occurs?
Post by: Bruno on October 29, 2010, 01:50:57 AM

I have to record my arterial and venous pressure at the start of each session and learn what action to take in the case of high/low pressures. The machine will alarm to tell me something is wrong. For example, low arterial pressure means obstruction between the site and the pump...clot, needle not inserted properly, kink in line...in other words the blood is not getting through as it should.