[Acute adverse effects of dialysis]

Adverse reactions to dialyzers are a not very frequent, but because of the serious, sometimes fatal course, a dreaded complication of haemodialysis treatment. Most important among these reactions are hypersensitive reactions (anaphylactoid, reaction type A to dialyzer), which develop as a rule within the 10th minute of the procedure, and the reaction caused by the action of perfluorohydrocarbon which develop hours after onset or even completion of haemodialysis. Explanation of the development of hypersensitive reactions (HSR) by complement activation and formation of anaphylatoxins C3a and C5a during contact of blood with the bioincompatible dialysis membrane has been abandoned. Evidence of the etiological role of ethylene oxide (ETO) in the development of HSR influenced the selection of materials for the production of dialyzers and sterilization during manufacture, it emphasized the importance of rinsing of the dialyzer in the dialysis centre and led to the wide application of alternative methods of sterilization by gamma radiation and steam. HSR may be also caused by overproduction of bradykinin and inhibition of its degradation or degradation of its metabolites. Excessive bradykinin production caused by dialysis membranes with a negative charge is potentiated e.g. by a lower pH and increased plasma dilution in the initial stage of haemodialysis. Inhibition of bradykinin degradation develops during treatment with angiotensin converting enzyme inhibitors (ACEI). In prevention of HSR associated with bradykinin in addition to elimination of a combination of a negatively charged dialysis membrane and ACEI treatment a part is played also by rinsing of the dialyzer before haemodialysis with a bicarbonate solution and the modification of the membrane surface (implemented by the manufacturer) which reduces its negative charge. The first reaction to the dialyzer in conjunction with perfluorohydrocarbon (PF-5070), used in production of some dialyzers for testing the integrity of their capillaries were first described in 2001 and have caused since then at least 50 deaths. Reactions associated with PF-5070 are still the subject of research and forensic investigations. Despite this they draw already now attention to the failure in manufacture of dialyzers, to the inadequacy of hitherto accepted testing procedures of dialyzers and the constant necessity of careful clinical, laboratory and post-mortem examination of dialyzed patients.