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Biomedical subjects

W H Dzik

Publications and source records attributed to W H Dzik.

At least 55 records · Page 3Linked to original sources
PubMed1990

Albumin supplementation in the critically ill. A prospective, randomized trial.

Albumin replacement to correct hypoalbuminemia in critically ill patients has been controversial. This study was a prospective, randomized trial of 25% albumin administration in 40 hypoalbuminemic (serum albumin, less than 25 g/L [2.5 g/dL]), critically ill patients. The treatment group (18 patients) received 25% albumin supplementation to achieve and maintain serum albumin levels of 25 g/L (2.5 g/dL) or greater, while the nontreatment group (22 patients) received no concentrated albumin. There was no clinical benefit from albumin therapy when assessing mortality (39% vs 27%, treatment vs control) or major complication rate (89% vs 77% of patients). There were also no significant differences in length of hospital stay, intensive care unit stay, ventilator dependence, or tolerance of enteral feeding, despite significant elevations of albumin in the treatment group. The costly use of exogenous albumin as treatment for hypoalbuminemia in this patient population does not appear to be justified.

Aged↗
PubMed1990

Intraoperative blood salvage: medical controversies.

Although a great deal has been learned about the medical aspects of intraoperative blood salvage, several fundamental medical issues remain controversial. As pressure increases to maximize the use of IBS, more research will be needed on the application of salvage techniques in cancer surgery and in the presence of bacterial contamination. The reintroduction of the use of devices that do not wash salvaged blood have reopened investigations into the effects of reinfusion of partially hemolyzed and partially clotted salvaged blood on coagulation, renal function, and cardiopulmonary performance. More studies are also needed so that empirically based standards of practice for the collection and storage of salvaged blood can be established. No longer confined to a few pioneering surgical departments, IBS is now widely practiced and likely to continue to grow rapidly. Knowledge and research of the medical issues surrounding its use will become increasingly valuable in transfusion medicine.

Animals↗
PubMed1990

Flow-cytometric method for counting very low numbers of leukocytes in platelet products.

We provide a detailed description of a new method for counting very low numbers of leukocytes present in platelet products. The method uses fluorescent staining of leukocyte DNA using propidium iodide and flow cytometry. The assay is accurate over a range of leukocyte concentrations from 0.1 to 10 WBC/microliter. We validated the method using specially designed dilution studies and applied it to the measurement of leukocyte content in leukocyte-depleted platelet products prepared by apheresis or filtration. This method should prove useful in studies which address the clinical impact of leukocyte-depleted platelet products.

Blood Platelets↗
PubMed1989

Refreezing previously thawed fresh-frozen plasma. Stability of coagulation factors V and VIII:C.

With the growth in autologous blood programs and the increased scrutiny of the indications for transfusion of fresh-frozen plasma (FFP), an increase has been seen in the number of occasions on which FFP was requested and thawed but then not transfused. The coagulation properties of FFP units that were refrozen and then rethawed were therefore studied. Fifty-eight units of plasma were studied, with each experimental unit of FFP paired with an identical control unit. Experimental units were frozen, stored at -65 degrees C, thawed, stored at 1 to 6 degrees C for various periods of time up to 24 hours, and then refrozen, stored at -65 degrees C, rethawed, and stored again in the refrigerator for up to 24 hours. Control units were frozen once at the time the experimental units were first frozen and thawed once at the time of the second thaw of the experimental units. Aliquots of plasma were sampled periodically and were later batch-tested for prothrombin time (PT), activated partial thromboplastin time (aPTT), and factor V and VIII:C activity. The results of coagulation testing of the twice-frozen plasmas were always within the normal range. There was a slight but statistically valid prolongation of the PT and aPTT and a decrease in the factor V and VIII:C levels for twice-frozen plasma compared with control plasma. The greatest decline occurred in the level of factor VIII:C. The measured deterioration in coagulation of twice-frozen FFP is unlikely to be of clinical importance. Refreezing FFP may eventually prove useful for rare donor, autologous, and massive transfusion programs.

Blood Preservation↗
PubMed1989

Should autologous blood that tests positive for infectious diseases be used or discarded? A decision analysis approach.

Decision analysis was applied to the question of whether to keep or discard autologous blood donations that test positive for viral markers. The decision is reached by analyzing a series of different events that lead to different outcomes. The probability of each event must be estimated and a value ("utility") assigned to specific outcomes. The underlying assumptions of the analysis are reviewed. After assigning a probability to each event and a utility to each outcome, one can compute a probability (P*) that is compared to the likelihood that the autologous donor will need transfusion. If the probability of transfusion exceeds P*, then keeping the infectious unit is favored. Otherwise, discarding the infectious unit is preferred. The analysis argues against a single, uniform national policy regarding the disposition of infectious autologous units. The method outlined provides a rational basis for setting policy regarding a controversial issue in Transfusion Medicine.

Blood Transfusion, Autologous↗
PubMed1989

Positive direct antiglobulin test result in dialysis patients resulting from antiformaldehyde antibodies.

Patients on chronic hemodialysis who are treated with reusable dialyzers sterilized with formaldehyde are known to have antibodies develop with N-like specificity. These sera have been shown to also react with formaldehyde-treated N-negative cells. This latter specificity has been referred to as antiformaldehyde (anti-Form). Because anti-Form develops presumably in response to formaldehyde-treated cells that gain access to the patient's circulation, the authors reasoned that recipient anti-Form once established might be capable of binding to cells exposed to formaldehyde during dialysis, resulting in a positive direct antiglobulin test (DAT) result and an eluate reacting only with formaldehyde-treated reagent cells. The authors studied 96 patients on chronic hemodialysis who were exposed to formaldehyde-sterilized equipment. Both anti-N-like and anti-Form specificities were found. Anti-Form was detected in the serum of 16% of patients when tested against 0.37% (w/v) formaldehyde-treated cells. Nineteen percent of patients demonstrated a positive DAT result. The presence of a positive DAT result was significantly associated with the presence of anti-Form in the patient's serum (P less than 0.05). Red blood cell eluates from two patients with a positive IgG DAT result and serum anti-Form demonstrated anti-Form in the eluate. Increasing the concentration of formaldehyde treatment of red blood cells resulted in increasing strength of reactions with anti-Form serum, suggesting that the sensitivity of serum and eluate testing could be modified by the method of cell preparation. As expected, the reactivity of anti-Form with formaldehyde-treated cells could not be neutralized by formaldehyde. The authors conclude that patients treated with formaldehyde-sterilized reusable dialysis equipment may on occasion have a positive DAT result and have an eluate that is nonreactive with the use of standard reagent cells but reactive with formaldehyde-treated cells.

Adult↗
PubMed1988

Stability of antigens on leukocytes in banked platelet concentrates: decline in HLA-DR antigen expression and mixed lymphocyte culture stimulating capacity following storage.

Repeatedly transfused thrombocytopenic patients frequently form antibodies directed against human leukocyte antigens (HLA) and become unresponsive to random donor platelet transfusions. Although exposure to foreign antigens borne on donor leukocytes appears necessary to provoke primary sensitization, the stability of leukocyte antigens during routine platelet storage is largely unknown. Accordingly, we serially measured the expression of surface markers on leukocytes derived from platelet concentrates during storage using immunofluorescence and flow cytometry. Our results indicate that the expression of class I HLA antigens, Leu-4 (T cell), and HLe-1 (pan leukocyte) remained stable on lymphocytes under standard platelet storage conditions, but that the percentage of lymphocytes bearing class II HLA antigens declined significantly over time. This decline in lymphocyte HLA class II expression was associated with a significantly diminished ability of stored leukocytes to stimulate blastogenesis in mixed lymphocyte culture. However, leukocytes retained the ability to respond in mixed lymphocyte culture (MLC) following storage. We also performed studies on lymphocytes cultured in the presence of cyclohexamide, which suggested that the expression of class I HLA antigens and B2 microglobulin are highly sensitive to the inhibition of protein synthesis, whereas the expression of class II HLA antigens, Leu-4, and HLe-1 are not. Our results may prove useful in understanding the mechanisms that lead to platelet refractoriness and in designing strategies to prevent HLA alloimmunization.

Blood Platelets↗
PubMed1988

Fibrinolysis during liver transplantation in humans: role of tissue-type plasminogen activator.

Human liver transplantation is frequently associated with a coagulopathy and bleeding diathesis developing during the anhepatic phase of surgery. The hemostatic defect has been attributed in part to accelerated fibrinolysis. In this study we evaluated changes in specific blood fibrinolytic parameters occurring in eight adult patients undergoing first-time orthotopic liver transplantation. Five of the eight patients experienced moderate to severe systemic fibrinolysis as reflected by alpha 2-antiplasmin consumption and fibrinogen degradation with the concomitant appearance of fibrin(ogen) degradation products. In association with these changes, an increase in tissue-type plasminogen activator (t-PA) activity and t-PA antigen levels was also observed. Fibrinolysis was most pronounced during the anhepatic phase of surgery and decreased after revascularization of the grafted liver. Three additional patients who underwent the same procedure manifested much less evidence of systemic fibrinolytic activation and had minimal elevation of t-PA antigen levels or activity. Urokinase-type plasminogen activator levels, although elevated in three patients, were disassociated from increased t-PA levels and concomitant systemic fibrinolysis. The operative course of those patients developing t-PA-associated fibrinolysis was characterized by shock, acidosis, generalized bleeding, and a need for substantially greater blood product support during surgery. These findings suggest that the observed fibrinolytic defect is related to increased circulating plasma levels of t-PA, presumably resulting from a combination of increased intravascular release and decreased hepatic clearance of t-PA. These observations may have implications for intraoperative therapy for the transplant-related coagulopathy and its associated bleeding.

Adult↗
PubMed1987

Development of metabolic alkalosis after massive transfusion during orthotopic liver transplantation.

Five patients undergoing orthotopic liver transplantation were investigated for changes in acid-base homeostasis secondary to large volume transfusions. All patients developed a transient acidemia during the operative period, followed by alkalemia which persisted into the early postoperative period. The patients received an estimated mean of 750 mEq of citrate, which appeared to cause metabolic alkalosis. The biochemical basis underlying the regulation of citrate metabolism that may have led to the timing, extent, and duration of the subsequent metabolic alkalosis is presented. Finally, the time course for the development of metabolic alkalosis may be a potentially sensitive indicator of early allograft function.

Acid-Base Imbalance↗
PubMed1986

Pulmonary complications of orthotopic liver transplantation.

Pulmonary complications following orthotopic liver transplantation (OLT) were prospectively evaluated in 18 individuals transplanted at the New England Deaconess Hospital. Of sixteen patients who survived the immediate postoperative period, 12 (75%) sustained a pulmonary complication. Of these complications, 64% were noninfectious--whereas 22% were infectious, and 14% probably infectious. Six of eight documented infections were caused by viruses of the herpes group. In four cases of viral pneumonitis other pulmonary pathogens were isolated (fungi-3, protozoan-1, bacteria-1). Unlike noninfectious complications, pulmonary infections were associated with a fatal outcome in five of six patients who died after OLT. Pulmonary complications are frequent and serious occurrences after OLT, and contribute to both the morbidity and mortality of this procedure. Compared with pulmonary complications seen after transplantation of other organs, OLT was associated with a higher proportion of noninfectious complications but a similar spectrum of pulmonary infections.

Adult↗
PubMed1985

Use of intraoperative blood salvage during orthotopic liver transplantation.

Human liver transplantation is a developing surgical technique that requires a large volume of blood support. There are no published results of the use of intraoperative blood salvage in liver transplantation. We used automated intraoperative blood salvage during 13 initial consecutive human liver transplants. The procedures required a median of 32 units of packed red blood cell support, of which an average of 45% was supplied by intraoperative salvage. The percent of the total blood use provided by intraoperative salvage increased with increasing total blood needs. Intraoperative blood salvage applied to liver transplantation resulted in a net savings of blood and hospital costs of approximately $1,000 per procedure.

Adult↗
PubMed1985

Suppressed expression of blood group B antigen and blood group galactosyltransferase in a preleukemic subject.

The B antigen activity was severely diminished in a patient's RBCs at the preleukemic stage prior to chemo- or radiotherapy. The amount of H sites of the patient's RBC membranes was found to be comparable to that of O RBC membranes. The activity of alpha (1----2) fucosyltransferase (H enzyme) was not severely decreased in the patient's plasma and bone marrow. However, the activity of alpha (1----3) galactosyltransferase (B enzyme), which converts H substance to B substance, was drastically reduced in the patient's bone marrow. Thus, the diminished B antigen in the patient's RBCs was caused mainly by the blockage of conversion of the H substance to B substance. It is suggested that the viral oncogene linked to the ABO locus at q34 of chromosome No. 9 would occasionally suppress the expression of blood group A and B enzymes and A and B antigens.

ABO Blood-Group System↗