External Quality Assessment of stat test intralaboratory turnaround times. Pilot study from the Members of the Working Group for the Standardization and Promotion of Turnaround Time Control under the Auspices of the Comitato Italiano per la Standardizzazione dei Metodi Ematologici e di Laboratorio.

We describe procedures, results and prospects of a pilot program in External Quality Assessment (EQA) of the stat test intralaboratory turnaround times. Our goals are to promote quality by systematic monitoring and comparison of performances by laboratories, continuous investigation into the state of the art of the processes from receipt of sample to transmission of results and creation of a data base for standardization of measures and definition of consensus values for turnaround time. Of 30 laboratories invited to participate, 25 took part, agreeing to record times of arrival and transmission for all determinations of three analytes (blood hemoglobin, serum/plasma potassium and plasma prothrombin time) for seven consecutive days and to continue for one or more further periods of seven days as necessary if there were less than 300 determinations for each analyte. Within a preset time limit, data were sent by e-mail on an Excel file and we sent back two reports per analyte, showing: i) the graph for time vs. percentage of tests completed and several measures of turnaround time; ii) results of all laboratories in graph form, allowing each laboratory to identify only its own data. The high proportion of participating laboratories among those invited (83%) encourages us to implement the EQA program systematically, on a half-yearly basis, extending it to all laboratories wishing to participate in Italy or elsewhere in Europe.

[Measurement of glycated hemoglobin with the Abbott IMx automatic analyzer]. / Misura dell'emoglobina glicata sull'analizzatore automatico Abbott IMx.

The Abbott IMx assay is an affinity method, based on boronate binding to glycated hemoglobin. A novel separation system, ion capture technology, is used for separation of GHb from non-GHb. Affinity-based GHb methods are reported not to be subject to interference from either aldimine intermediates (pre-Alc fraction) or Hb variants that can comigrate in ion-exchange based chromatographic methods with the HbAlc fraction or with HbAO, having, in both cases, an unreliable % HbA1c result. The purpose of the study was to investigate the analytical performance of the GHb IMx assay, illustrating also a case study involving an abnormal hemoglobin variant.

Simultaneous measurement of reticulocyte and red blood cell indices in healthy subjects and patients with microcytic and macrocytic anemia.

Using the new Bayer H*3 hematology analyzer (Leverkusen, Germany), we have determined red blood cell and reticulocyte indices in 64 healthy subjects, in patients with microcytosis due to iron deficiency (58 patients) and heterozygous beta-thalassemia (40 patients), and in patients with macrocytosis (28 patients). We found in all cases that reticulocytes were larger than mature red cells by 24% to 35%, with a hemoglobin concentration 16% to 25% lower and a similar hemoglobin content. The correlation between red cell and reticulocyte indices was strikingly tight (r = .928 for volume, r = .929 for hemoglobin concentration, r = .972 for hemoglobin content) in all four groups, regardless of red blood cell size. The ratio of reticulocyte to red blood cell mean corpuscolar volume (MCV ratio) was constantly above 1. Inversion of the MCV ratio was observed only in four patients. It was always abrupt and transitory and was associated with erythropoietic changes leading to the production of red blood cells of a different volume (treatment of megaloblastic anemia, functional iron deficiency, bone marrow transplantation). In two cases of marrow transplantation, reticulocyte volume fell during the aplastic phase after conditioning chemotherapy and then rapidly increased up to values higher than before; this production of macroreticulocytes was the earliest sign of engraftment.

[Energy expenditure during a pregnancy complicated by post-traumatic coma: analysis of 2 clinical cases]. / Spesa energetica in corso di gravidanza complicata da coma post-traumatico: analisi di due casi clinci.

OBJECTIVE: To analyze the measured resting energy expenditure, the clinical evolution and the nutritional therapy of two pregnant women complicated by post-traumatic coma and sepsis. DESIGN: Clinical study. SETTING: The ICU of Neurosurgery in Regional Hospital in Italy. PATIENTS: Two subjects with head trauma due to a motor vehicle accident. METHOD: The resting energy expenditure was measured (M-REE) by indirect calorimetry by oxygen consumption (VO2) and carbon dioxide production (VCO2). Values were controlled in patients with a hemodynamic stability every 4 hours. Predicted REE (P-REE) was calculated according to the Harris-Benedict formula. A total parenteral nutrition (1.2-1.3 x M-REE) composed of dextrose (70-80% of total caloric amount) and fat (20-30%) was infused in both the subjects. As an average 12-15 g of nitrogen were infused daily. RESULTS: VO2 and VCO2 increased during the study (case 1: from 225 +/- 33 to 325 +/- 35 ml/min; p < 0.02; LR: p < 0.0001; VCO2: from 170 +/- 24 to 289 +/- 23 ml/min; p < 0.0001. Case 2: VO2: from 239 +/- 22 to 315 +/- 35 ml/min; p < 0.05; LR: p < 0.01. VCO2 from 177 +/- 31 to 247 +/- 22 ml/min; p < 0.05; LR: p < 0.001). M-REE/kg increased with statistical significance during the study (case 1: from 23.6 +/- 4.1 to 34.1 +/- 4.3, p < 0.05, LR: p < 0.005; case 2: from 23.7 +/- 5.8 to 33.4 +/- 7.7, p < 0.05, LR: p < 0.05). A physiological variation in oxidative capacity on nutritional substrates was reported throughout the study. CONCLUSION: Sepsis and miscarriages following trauma seem to be the cause in an increase of the energy expenditure rather than pregnancy itself. However our observations must be viewed with caution because they are based on a small number of patients.

Cardiac cachexia: preoperative and postoperative nutrition management.

The present study examined the hemodynamic and metabolic effects of nutrition support in patients with malnutrition secondary to severe mitral valve disease and congestive heart failure. Pulmonary artery pressure measurements, echocardiographic studies, gas exchange measurements, immune function tests, and clinical evaluations were made on hospitalized patients 2 weeks before and 3 weeks after surgery for valve replacement or annuloplasty. All patients received a total daily energy intake of 20 to 30 kcal/kg, four of the patients preoperatively as a combination of oral food plus parenteral nutrition and these four patients plus two additional patients as only parenteral nutrition in the early postoperative period. All six patients received nutrition support as oral food plus parenteral nutrition in the late postoperative period. Compared with baseline, nutrition support was associated with stable hemodynamic function, unchanged whole-body oxygen consumption and carbon dioxide production, and improved clinical indices both before and after surgery. Comprehensive hemodynamic, metabolic, and clinical studies thus indicate that acceptable levels of nutrition support can be provided to malnourished patients with severe congestive heart failure, which improves their clinical status and does not adversely influence cardiac function.

Effects of a continuous diltiazem infusion on renal function during cardiac surgery.

Thirty-five male patients undergoing coronary artery surgery were studied to investigate renal function during a continuous infusion of the calcium channel blocker diltiazem. All patients had preoperative renal function within normal limits (serum creatinine below 0.133 mmol/L) and were randomly divided into three groups: Control (C), Diltiazem 1 (D1), and Diltiazem 2 (D2). Diltiazem was infused in D1 (1 microgram/kg/min) and D2 (2 micrograms/kg/min) patients throughout surgery and during the following 36 hours. Glomerular function was investigated using the endogenous creatinine clearance while tubular function was assessed by means of water and sodium reabsorption tests, as well as urinary enzyme activity measurements. Hemodynamic monitoring was performed using a pulmonary artery catheter. The glomerular filtration rate of C and D1 patients showed a significant fall during cardiopulmonary bypass (CPB) with respect to the prebypass period and returned to the baseline values only in the postoperative period. A similar change was not observed in D2 patients. The analysis of variance demonstrated that the glomerular filtration rate was significantly higher in Group D2 versus Group C during and after CPB (P = 0.03 and P = 0.04, respectively). Furthermore, after CPB, urinary output was significantly improved in D2 patients, both versus C and D1 patients (P = 0.003), notwithstanding a lower mean arterial pressure in the D2 Group (P = 0.04 v C Group). Tubular function was not influenced by diltiazem infusion. It is concluded that a continuous diltiazem infusion, at a dose of 2 micrograms/kg/min during cardiac surgery, may be useful to prevent a decrease in glomerular function secondary to cardiopulmonary bypass.

[Mass transfer of magnesium in hemodialysis]. / Mass-transfer del magnesio in emodialisi.

The rate of mass-transfer (MT) of magnesium during hemodialysis was studied in thirty-five patients with hypermagnesemia (Mg = 3.75 +/- 0.72 mg/dl) undergoing chronic hemodialysis. The aim of the study was to verify which is the best dialytical approach to remove the excess of magnesium. The concentration of Mg in the dialysate was of 1.82 mg/dl for all patients. MT was -0.51 +/- 0.36 g and no statistical difference was found between patients treated with cuprophan hollow fibers dialyzers, PAN and cuprophan plates. Mg MT is not correlated with dialysis duration (r = -0.23; p:ns), urea clearance (r = -0.08; p:ns), KT/V index (r = -0.03; p:ns), blood flow (r = -0.15; p:ns). In conclusion from our data, in agreement with other Authors, reduction of serum Mg levels is more convenient by obtained by a decrease in Mg concentration in the dialysate under 1.82 mg/dl, in order to increase the blood-dialysate concentration gradient.

Comparison between three mathematical models of KT/V.

In thirty anuric patients undergoing chronic hemodialysis the KT/V values obtained with the formula: (formula; see text) were compared with the values obtained with the following two formulae: (formula; see text) The results given by formulae B and C differed from those with formula A respectively by 12.81 +/- 11.98% and 10.38 +/- 3.64%. For routine determination of KT/V we suggest the use of formulae A and C as a means of establishing rapidly, in one step, whether the hemodialytic treatment examined is adequate.

The use of immobilized enzyme reactors in continuous-flow analyzers for the determination of glucose, urea, and uric acid.

We describe the use of immobilized enzymes in assay methods for the determination of glucose with glucose oxidase, uric acid with uricase, and urea with urease in serum samples. The enzyme reactor tubes were adapted to continuous-flow analyzers (Technicon AA II, SMA 12/60, and SMAC) used in routine laboratory determinations, and results with their use were compared to those from assays involving soluble enzymes. We substituted the reactors for the free enzyme reagents in the respective channels of the SMA 12/60 and SMAC, without modifying the parameters of the remaining channels. We compared assay sensitivity, precision, and carryover for immobilized and conventional liquid enzymes. Immobilized enzyme reactors provide accurate, reliable, convenient, and economical alternatives to the use of free enzyme reagents in these systems.

[Study of a family with a slow type of bisalbuminemia and of 2 other familial cases]. / Studio di una famiglia portatrice di bisalbuminemia di tipo lento, e di altri due casi familiari.

The AA. illustrate cases of slow type bisalbuminaemia that they happen to observe on three different family one of which, on a family of north italian origin, has been particularly developed. The cases have been studied on the various components of each family living and to be found, on serum and urine, using electrophoretic methods on cellulose acetate and acrylamide gel and also using the immunoelectrophoretic and cromatographic method on serum after hydrolysis. Cases taken in account, together with results of investigation, add up to those already given to the litterature.