Cause of Device-Related Incident
Device factors; User errors

Clinical Specialty or Hospital Department
Clinical/Biomedical Engineering; Dialysis; Nephrology

Device Factors
Device failure

Document Type
Hazard Reports

External Factors
*Not stated

Mechanism of Injury or Death
Exposure to bloodborne pathogens; Exsanguination; Failure to deliver therapy; Infection

Support System Failures
*Not stated

Tampering and/or Sabotage
*Not stated

User Errors
Abuse of device

Dialyzers, Hemodialysis, Hollow-Fiber [11-234]

Header Cracks Related to Reprocessing of Single-Use Hemodialysis Dialyzers

Hazard [Health Devices Aug-Sep 1995;24(8-9):359-61]


A member hospital reported that several of one brand of hollow-fiber dialyzers used in two of its five dialysis clinics developed cracks in the threaded portion of the headers (i.e., end caps). The affected models are those in predominant use in these clinics. In each case, the cracks were noted after the dialyzers had been reprocessed several times. (Note that, although these dialyzers are labeled as single-use devices, it is common for dialysis clinics to reprocess and reuse them several times.)

The reported cracks are believed to be related to contact with some chemicals that have not been validated (by the chemical manufacturers) for use in the reprocessing of dialyzers. While most of the cracks were found during reprocessing, one cracked dialyzer was inadvertently used in a patient's treatment. This patient lost a significant amount of blood and required a transfusion.

A search through the ECRI problem reporting databases revealed several similar reports with the incident brand of these products since 1993; it was also revealed that other dialyzer manufacturers have reported similar problems. While no patient injuries have been described in these reports, the dialyzer cracks could result in significant blood loss.

Manufacturer Action

Although the manufacturer of the incident dialyzer has not received reports of serious injury related to header cracks, it has received sporadic reports of such occurrences from a few clinics across the United States and has been investigating the problem. While the manufacturer recognizes that the problem may be underreported, based on its investigation, it believes that the incidence of header cracking is very low. The investigation revealed that the headers may crack after multiple exposures to chemicals (e.g., some germicidal agents) that they may come in contact with during reprocessing at hemodialysis clinics. Also, the common practice of clearing bubbles during priming by forcefully tapping the dialyzer with hard instruments, such as hemostats, could possibly contribute to the problem.

The manufacturer has alerted affected clinics to the interaction of some chemicals with dialyzer materials. In addition, in late 1994, it introduced a change in the manufacture of its dialyzers that it hopes will eliminate dialyzer cracking.


Cracking of reprocessed, single-use dialyzers is not unique to one supplier's product line, and as the search of our problem reporting database confirmed, other dialyzer manufacturers have received similar reports. Clinics that choose to reprocess single-use dialyzers should be aware of this risk.

Agents containing aromatic compounds (those with benzene rings), such as disinfectants and some antibacterial soaps and lotions, can attack the polycarbonate in dialyzers. However, the cracking of the polycarbonate headers is a long-term exposure effect, and the damage caused by brief exposure to the chemicals is rarely severe enough to result in immediate cracking. Reportedly, reprocessing at the affected clinics involved using at least one agent containing aromatic compounds; also, regular, incidental exposures to aromatic compounds in solutions used to disinfect work surfaces or to wash hands may have occurred.

In its 1993 standard, Reuse of Hemodialyzers, the Association for the Advancement of Medical Instrumentation (AAMI) states that, "certain commercial low-level disinfectants may cause some plastics used for dialyzers to crack after repeated or prolonged exposure."(1) While different plastics used for dialyzers may be incompatible with different agents, at least two common disinfecting agents can be used safely with most dialyzers to disinfect their external surfaces. AAMI recommends that those dialysis clinics that do reprocess use bleach diluted to a concentration of 0.05% to 0.1% when cleaning the dialyzers. (Household bleach is typically 5.25% chlorine bleach.) Renal Systems, the manufacturer of Renalin, recommends the use of 1% Renalin to wipe down the exterior of dialyzers. Hospitals should try to standardize on reprocessing and disinfecting agents to minimize potential chemical incompatibilities that could exacerbate cracking and to prevent dangerous chemical reactions that could affect healthcare workers.


  1. Discuss with reprocessing personnel the possibility of dialyzer cracking as a result of chemical attack, and ensure that they are using only recommended germicidal agents for both dialyzer reprocessing and disinfecting external surfaces of the dialyzer. If the product labeling does not list the contents of a germicidal agent, contact its manufacturer, and request the material safety data sheets (MSDSs); also, ask dialyzer manufacturers if they know of any interactions with their products.
  2. Be aware that even repeated incidental exposure of the dialyzer to nonvalidated agents (e.g., antibacterial soaps or lotions) could lead to header cracking. Also note that the cracking problem may be exacerbated by the common practice of clearing bubbles by tapping the dialyzer with a hard object, such as a hemostat. (A rubber [reflex] hammer or the palm of the hand could be used instead.)
  3. Inspect dialyzers for cracks after reprocessing and before patient use. If cracks are discovered, do not use the dialyzer, and be sure to alert manufacturers to the problem. Reporting the cracks will help manufacturers track trends and may help your facility eliminate the problem.
  4. When practical, standardize on agents used for reprocessing and disinfecting to avoid potential chemical interactions that could contribute to dialyzer cracking problems or lead to the production of noxious fumes. For example, when disinfecting the dialyzer exterior, use diluted chlorine bleach if you use chlorine bleach for cleaning the interior during reprocessing, or if your reprocessing is Renalin-based, use 1% Renalin.
  5. If your dialysis clinic is concerned that disinfectants used in earlier reprocessings may have left dialyzers prone to header cracking, contact the dialyzer manufacturer. While the risk of patient injury should be low, the manufacturer can assist in determining the potential for cracked headers and in taking preventive measures.


  1. Association for the Advancement of Medical Instrumentation (AAMI). Reuse of hemodialyzers [American National Standard]. Arlington (VA): AAMI , 1993:8; ANSI/AAMI RD47-1993.  


Dialyzers, Hemodialysis, Hollow-Fiber [11-234]

Cause of Device-Related Incident

Device factor: Device failure

User error: Abuse of device

Mechanism of Injury or Death

Exposure to bloodborne pathogens; Exsanguination; Failure to deliver therapy; Infection

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