[The purpose of clinical laboratory accreditation in transplantation medicine]. / Znacenje akreditacije klinickih laboratorija u transplantacijskoj medicini.

Although transplantation of solid organs has become a more standardized method of treatment, liver transplantation represents an exceptional multidisciplinary clinical procedure requiring understanding of specific pathophysiological changes that occur in the end stage of liver disease. Liver transplantation has been performed at Merkur University Hospital since 1998, with 360 transplantations performed to date. The most common indications are alcohol liver disease, cirrhosis caused by hepatitis B and C virus, hepatocellular carcinoma and cryptogenetic liver cirrhosis. Laboratory tests required for liver transplantation are performed at Department of Clinical Chemistry, Merkur University Hospital, accredited according to ISO 15189 in 2007 for the areas of clinical chemistry, laboratory hematology and coagulation, laboratory immunology-cell immunophenotyping, and molecular diagnosis. The complexity of liver transplant patients requires constant interaction between the anesthesiologist team and clinical laboratory, which has to ensure fast and efficient intraoperative monitoring of biochemical and liver profile: electrolytes and acid-base status, complete blood count, coagulation profile and monitoring of graft function according to the individual patient's health status. Dynamics of intraoperative changes is measured in whole arterial blood samples on a Nova Biomedical Stat Profile Critical Care Xpress mobile acid-base analyzer. Frequent monitoring of ionized calcium and magnesium levels is very important because of citrated blood transfusion and for appropriate therapeutic procedure. During anhepatic stage, there is a progressive increase in lactate level concentration. After reperfusion, a rapid increase in lactate clearance is an excellent indicator of stable graft initial function and its adequate size. During the transplantation procedure, there is usually a biphasic acid-base disturbance characterized by metabolic acidosis and then by metabolic alkalosis. The loss of base equivalents starts during the dissection stage and accelerates during the anhepatic stage. Fast and efficient intraoperative monitoring of hematological tests and coagulation status is of great help in detecting the cause of possible hemorrhage and consequential complications during transplantation procedure. The possibility of organ and tissue transplantation mostly depends on well regulated international cooperation in the areas of donating, transplanting and exchange of required organs and tissues, while laboratory test results must be comparable regardless of their geographical area, methodology employed or analytical equipment used, which is mainly warranted through accreditation according to the international ISO 15189 standard.

Accreditation of medical laboratories in Croatia--experiences of the Institute of Clinical Chemistry, University Hospital "Merkur", Zagreb.

Since 2003 when the international norm for implementation of quality management in medical laboratories (EN ISO 15189, Medical laboratories--Particular requirements for quality and competence) was established and accepted, accreditation has become practical, generally accepted method of quality management and confirmation of technical competence of medical laboratories in the whole world. This norm has been translated into Croatian and accepted by the Croatian Institute for Norms as Croatian norm. Accreditation is carried out on voluntary basis by the Croatian Accreditation Agency that has up to now accredited two clinical medical biochemical laboratories in the Republic of Croatia. Advantages of accredited laboratory lie in its documented management system, constant improvement and training, reliability of test results, establishing users' trust in laboratory services, test results comparability and interlaboratory (international) test results acceptance by adopting the concept of metrological traceability in laboratory medicine.

Cholinesterase unit establishment and issuing of >>Warning Cards<< for carriers of suxamethonium sensitive serum butyrylcholinesterase variants.

Recognition of butyrylcholinesterase (EC 3.1.1.8) variants in human serum is essential to identify patients who may be susceptible to a prolonged reaction of suxamethonium and mivacurium, short-acting muscle relaxants. Thus they can be given appropriate advice along with their relatives who may be similarly affected. Therefore, Cholinesterase Unit for detection of individuals, carriers of inherited suxamethonium sensitive butyrylcholinesterase variants was established at the Institute for Clinical Chemistry of the Clinical Hospital >>Merkur<<, Zagreb, Croatia. A study was conducted on sera from patients referred to the Unit. Butyrylcholinesterase variants were determined by measuring the enzyme activity and inhibition by specific inhibitors in the sera of 384 patients and of the members of seven families. Cholinesterase Unit issued >>Warning Cards<< to the carriers of inherited serum butyrylcholinesterase variants in order to avoid prolonged apnea that suxamethonium might cause.