Hematocrit and Residual Renal Creatinine Clearance in Patients Undergoing Continuous Ambulatory Peritoneal Dialysis (CAPD)

In a recent report, the relationship between renal creatinine clearance and hematocrit in patients with renal creatinine clearances, ranging from 55 to 8 mL per min. per 1.73 square meters of body surface area, was analyzed (1). The authors of this study have performed a crosssectional analysis of the relationship of hematocrit to residual renal creatinine clearance in patients on continuous ambulatory peritoneal dialysis (CAPD). The authors of this study wanted to examine whether or not these hematocrits fall within extrapolations of the published 95% confidence limits for males and females with renal failure prior to end-stage renal disease and dialytic intervention. Authors also compare d regression intercepts at residual creatinine clearances of 0. Most of the CAPD patients had hematocrits within the upper half or above the extrapolated 95% confidence limits for the predialysis population. Within the CAPD population, there were no significant correlations of hematocrit with residual creatinine clearance at these lower ranges. The degree of scatter in the CAPD population for hematocrit values was similar to that in the predialysis population. Residual creatinine clearance appears to be a crude index of the increasing severity of multiple factors that may contribute to the anemia. CAPD appears to maintain or improve hematocrit as renal mass and function decline.

Universal fresh frozen plasma (Uniplas): a safe product in open-heart surgery

OBJECTIVE

To test the tolerability and safety of the universal plasma Uniplas [solvent/detergent (SD)-treated plasma], infused regardless of the patient's blood group.

DESIGN

Prospective, parallel group, controlled and observer-blinded study, randomized with respect to patients requiring plasma transfusion.

SETTING

Cardiothoracic operating room and ICU in a university hospital.

PATIENTS

Eighty-four patients undergoing open-heart surgery comparing three parallel treatment groups and one control group.

INTERVENTIONS

The Uniplas treatment group was subdivided into patients with blood group A, B or AB, and group O. The treatment group receiving Octaplas of type AB, was not subdivided. Patients who did not require any plasma transfusion served as control.

MEASUREMENTS

Complement activation (C3bc, TCC), direct antiglobulin test (DAT) and other immunohaematological tests, tests for haemolysis, and relevant clinical observations during treatment phase. Blood samples were collected again after 6 months for evaluation of viral safety.

RESULTS

Of the 84 patients, 29 served as control group. Uniplas was transfused in 36 of the patients (1-23 units). Octaplas was transfused in 19 patients (1-11 units). During the study no clinical adverse events related to plasma transfusion were observed. The degree of complement activation C3bc and TCC, a recommended test for biocompatibility, did not show any increased activation after Uniplas or Octaplas transfusion. No haemolytic reactions, positive DAT-tests or viral transmissions were observed after Uniplas transfusion.

CONCLUSION

In open-heart surgery, Uniplas, which can be transfused regardless of a patient's blood group, was well-tolerated and gave no adverse drug reactions.

Human complement activation by polygeline and dextran 70

The complement cascade is activated during cardiopulmonary bypass (CPB) and in trauma victims. In order to study whether plasma expanders may contribute to complement activation in these settings, fresh human serum was incubated with dextran 70 and polygeline. C3-activation products and the terminal complement complex (TCC) were quantified in enzyme immunoassays. At 37 degrees C, dextran caused immediate, dose-dependent C3 activation and TCC formation with decline later in the rate of TCC formation relative to serum-saline controls. High doses of polygeline caused slight activation after 15-30 min. The authors tested also the activation under conditions comparable to those found during clinical CPB. Activation induced by dextran and polygeline was increased by dilution of the serum. Furthermore, the plasma expanders counteracted the well-known inhibitory effects of heparin (4 IU/ml) and moderate hypothermia (30 degrees C) on complement activation. The authors conclude that dextran, and to a lesser extent polygeline, may contribute to complement activation during CPB and other clinical settings such as shock treatment.

Complement activation by extracorporeal circulation: effects of precoating a membrane oxygenator circuit with human whole blood

In an in vitro study of extracorporeal circulation (ECC), uncoated oxygenators (UC), oxygenators precoated with whole human blood (CN) and oxygenators precoated with blood and then rinsed with Ringer's acetate (CR) all significantly (p less than 0.001) activated the initial and terminal parts of the complement cascade. After 60 min C3 activation had increased by 692% (UC), 750% (CN) and 393% (CR), and terminal complement complex (TCC) concentrations by 194% (UC), 215% (CN) and 273% (CR). C3 activation was significantly (p less than 0.05) less in the CR than in the other groups. There was no statistical intergroup difference in increase of TCC concentration. Complement activation was accompanied by a significant drop in neutrophil counts, which was uninfluenced by coating or rinsing. The observed dissociation of the complement cascade shows that assessment of activation products from both parts is necessary for evaluation of total complement activation. The study suggests that protein precoating may improve biocompatibility of ECC.

Erythroid progenitor growth in erythrocytosic transplanted patients

In 55 patients who underwent renal transplantation, erythrocytosis (E) was observed in 6. In all patients, the growth of erythroid progenitors [burst-forming unit erythroid (BFU-e)], using mononuclear blood cells, was evaluated in in vitro cultures. The results showed a significant increase of serum erythropoietin (s-Ep) in erythrocytosis and in nonerythrocytosis patients with a subsequent decrease when hematocrit (Hct) and hemoglobin (Hb) reached high levels, showing a recovery of a feedback control system. Notwithstanding the diminution of s-Ep, six patients demonstrated further progressive rise of the Hct and Hb to a final state of E. The in vitro BFU-e cultures from these patients showed a noticeable sensitivity to progressively reduced doses of Ep and also the capacity to develop a few colonies when the medium was Ep-free. These results were not verified using peripheral blood depleted of monocyte and/or T lymphocyte cells. Therefore, in transplanted patients with erythrocytosis, it is possible that particular cellular interactions stimulate an early hyperproliferation of BFU-e with a greater Ep sensitivity and at least partly the capacity to grow also in the absence of Ep.

Complement activation and hypersensitivity reactions to dialysis membranes

Certain patients receiving hemodialysis experience recurrent chest pain, dyspnea, and hypotension during exposure to new cuprophane-membrane dialyzers (the "first-use syndrome"). Because activation of complement may be involved in these events, we examined in vivo complement activation with new cuprophane membranes and in vitro activation by zymosan in 6 such patients, and compared them with 10 patients who did not have symptoms during dialysis. All patients with the first-use syndrome had maximal complement activation 10 minutes after initiation of dialysis, with C3a des-arginine (desArg), the stable metabolite of C3 activation, equal to 8533 +/- 157 ng per milliliter (mean +/- S.E.M.). In asymptomatic patients the maximal C3a desArg value occurred at 15 minutes and was only 2907 +/- 372 ng per milliliter (P less than or equal to 0.0001). At a concentration of 3.8 x 10(-5) g of zymosan per milliliter, patients with the first-use syndrome had a C3a desArg level of 29.6 +/- 1.4 micrograms per milliliter, whereas it was only 16.6 +/- 2.3 micrograms per milliliter in asymptomatic patients (P less than or equal to 0.0001). Two other patients, who experienced cardiopulmonary collapse during the first two minutes of dialysis, had a C3a desArg level of 18,900 and 7800 ng per milliliter, respectively. We conclude that the occurrence of adverse symptoms associated with new cuprophane-membrane dialyzers correlates with complement activation.