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At least 19 recordsLinked to original sources
PubMed1977

Hemoglobinometry: A comparison between the hemiglobincyanide method and the Coulter S counter.

The relative accuracy and precision of the Coulter S Counter have been evaluated in comparison with manual hemiglobincyanide determination according to the recommendations of the International Committee for Standardization in Hematology. Some improvements in the manual procedure, such as centrifugation of hemiglobincyanide solutions and the use of the detergent Triton X-100, were also tested. The Coulter S Counter generally gives higher precision in comparison with the manual method. Nevertheles, Coulter S determinations are systematically lower due to both constant and proportional errors. The available data ranged between hemoglobin values of 11.5 and 18.5%, giving differences of 0-8% between hemoglobin values determined by the Coulter S Counter and the hemiglobincyanide method.

Detergents↗
PubMed1977

The calibration of automated instruments for accuracy in hemoglobinometry.

The surveys of the College of American Pathologists indicate a consistent bias between the manual "reference" method for hemoglobin determinations and the Coulter S measurements. The Coulter S hemoglobin values are invariably lower; the difference averages 0.3 g/dl. The commonly used calibration methods for the Coulter appear to be subobtimal. The hemoglobin calibration and quality assurance method proposed by Bull and colleagues is advocated as the presently most acceptable method. Commercial hemoglobin control materials should not be used for hemoglobin calibration.

Automation↗
PubMedDate not supplied

Changes in blood volume during dialysis are dependent upon the rate and amount of ultrafiltrate.

Actual circulating blood volume during dialysis therapy can be monitored by continuous hemoglobinometry. Using this method in 15 stable, clinically nonoverhydrated dialysis patients, blood volume was recorded applying different modes of ultrafiltration: constant ultrafiltration (less than 500 ml/hr); high initial (greater than 1,500-2,000 ml/hr), subsequently decreasing ultrafiltration; and intermittently high (greater than 1,500 ml/hr) ultrafiltration. Mean amount of ultrafiltrate in all patients was 3,400 ml. Mean decrease in blood volume by 20% was generally tolerated without a decrease in blood pressure. Irrespective of the different modes of ultrafiltration, a decrease in blood volume was dependent only on the amount of ultrafiltered fluid. A constant, low ultrafiltration rate was not superior to a high ultrafiltration rate. In stable dialysis patients, decrease in blood volume is dependent only on the amount of ultrafiltrate. Up to a 20% decrease in blood volume, fluid can be removed from the patient even at a rate of 2,000 ml/hr.

Blood Flow Velocity↗
PubMedDate not supplied

Less symptomatic hypotension using blood volume controlled ultrafiltration.

Symptomatic hypotension due to ultrafiltration (UF) is one of the most frequent unwanted side effects of dialysis therapy. Using hemoglobinometry for continuous monitoring of blood volume (BV), ultrafiltration rate (UFR) can be adapted to actual changes in BV. A control system is shown in which UFR is set according to a predefined profile of BV. The conditions of control are: relative BV shall decrease steadily; BV shall decrease rapidly during the first 60 min of dialysis, thereafter decrease in BV should be less; UFR shall be as high as possible; and dry weight should be obtained within a given time. Application of this controlled UF method in 10 dialysis patients shows significantly fewer hypotensive periods and muscle cramps compared to conventionally constant UFR. It is concluded that BV controlled UF is an important step toward optimizing dialysis therapy.

Blood Flow Velocity↗
PubMedDate not supplied

Vasoactive hormones during hemodialysis with intermittent ultrafiltration.

The correlations between actual blood volume (BV), blood pressure (BP), heart rate, and plasma levels of renin activity (PRA), serum aldosterone (ALD), antidiuretic hormone (ADH), epinephrine (E), norepinephrine (NE), atrial natriuretic factor (ANF), cGMP, and cAMP were investigated in 10 stable patients during HD. HD consisted of four periods of about 60 min each. One half with an UF rate greater than 1,000 ml/h, followed by a time interval of 30 min without UF resulting in a "saw tooth" profile of BV. Decrease in BV was measured by continuous hemoglobinometry. Average total decrease in BV was 25%, while BP and HR did not change significantly. E, NE, ANF and ADH levels were directly related to actual changes in BV, suggesting that BP regulation in this special mode of HD is mainly supported by endogenous catecholamine and ADH secretion. The second messenger cGMP did not follow actual BV changes, but showed a significant decrease correlated with diminished BV. A significant change in PRA and ALD was missing. It is concluded that vascular stability in these patients is maintained by the response of catecholamins and ADH to decrease in blood volume, and not by the renin-aldosterone system.

Aldosterone↗
PubMedDate not supplied

[Envenomation by Echis Carinatus in Africa: clinical study and evolution. Indications for antivenins].

In North Cameroon, venom inoculations by Echis Carinatus are frequent and severe and thus pose a serious problem at Public Health Services. 48 bites without antivenomous serum injection have been considered in Garoua, Benoue valley North Cameroon. Without antivenomous serum light inoculations heal spontaneous by in a couple of days about 20% of the average clinical forms are evoluting insidiously to severe globulolysis. The great majority of severe inoculations lead to dreadful hemorrhagic threatening the life of patients. New borns and infants are particularly exposed, it is not advisable to inject systematically antivenomous serum. But it has to be considered as compulsory in the three following clinical situations before 11 years of age, venom inoculation often brings about fast aggravation, mainly in new borns, after 11 years and at adult age, when clinical signs are of great concern, when hemoglobinometry indicates less than 9 gr/100 ml after 48 hours of evolution in youngs and adults, but without any symptom of severity.

Adolescent↗
PubMedDate not supplied

Low-dose heparinization can be used with DEAE-cellulose hemodialysis membranes.

The ability of DEAE-cellulose (Hemophan) membranes to bind heparin may reduce bioavailable heparin and predispose to dialyzer clotting, thus preventing use of Hemophan with low-dose heparin. To examine this possibility, residual blood volumes were determined following 95 treatments with dialyzers containing Hemophan membranes in 11 patients. No heparin was added to the saline used to prime the dialyzers. The anticoagulant effect of heparin was measured using recalcified activated clotting times (RACT). Two heparin doses, calculated by a pharmacokinetic model to increase baseline RACT by 12.5% and 25%, were used for each patient. The mean heparin loading doses were 10.2 +/- 2.8 and 15.3 +/- 2.2 IU/kg, respectively, and the mean infusion rates were 11.1 +/- 3.2 and 14.7 +/- 3.2 IU/kg/h, respectively. Residual blood volumes were determined by red cell lysis and hemoglobinometry. In 88 treatments, residual blood volume averaged 1.6 +/- 1.5 ml. In the other seven treatments, residual blood volume greater than 10 ml was seen. In five of these cases, clotting appeared to propagate from the arterial drip chamber. Residual blood volume did not correlate with the level of heparin. The data show that low-dose heparin can be used with Hemophan membranes, and suggest that blood tubing design may be an important factor in blood circuit clotting during hemodialysis.

Adult↗
PubMed1977

The conjunctival sickling sign, hemoglobin S, and irreversibly sickled erythrocytes.

Sixty-five patients with hemoglobins AS, SC, and SS were investigated in a masked fashion. We observed a statistically significant positive correlation between the severity of conjunctival sickling signs and the counts of irreversibly sickled cells in each hemoglobinopathy group. We also observed a statistically significant positive correlation between the severity of the conjunctival vasculopathy and the percentage of sickle hemoglobin in the total group of patients with hemoglobins AS, SC, and SS.

Adolescent↗
PubMed1979

Cardiovascular disease risk factor variables during the first year of life.

Cardiovascular risk factor variables were measured in a cohort of 440 infants at birth 6 months, and 1 year of age. Blood pressures at 6 months of age were 93/47 mm Hg (systolic/diastolic pressure, fourth phase) and 97/51 mm Hg at 1 year of age. Serum total cholesterol, beta-lipoprotein, and alpha-lipoprotein levels rose dramatically from birth to 1 year of age. Serum triglycerides also showed an increase from birth to 6 months of age, but a decrease from 6 months to 1 years of age. At 6 months of age, the infants were consuming 949 kcal and at 1 year, 1,356 kcal. A statistically significant correlation between serum cholesterol level and protein, fat, cholesterol, and carbohydrate intake was noted at 1 year of age. These observations provide a background for tracing the evolution of risk factor variables as part of the early natural history of arteriosclerosis.

Anthropometry↗
PubMed1975

Splenectomy for hematologic depression in lymphocytic lymphoma and leukemia.

Fifty patients with lymphocytic lymphoma and chronic lymphocytic leukemia underwent splenectomy for various combinations of anemia, thrombocytopenia, and leukopenia. All of these patients had advanced lymphoproliferative disease, and most had infiltration of bone marrow by neoplastic cells. Good response in all hematologic parameters was obtained in 27 of 48 evaluable patients. An additional 13 patients responded in one or two parameters; there were only 8 complete failures. The over-all surgical mortality was 8%. The median duration of response was 4 months, and the mean, 7 months. Increased tolerance to further antitumor therapy and a decreased transfusion requirement were seen among responding patients. Those patients with anemia who had evidence of shortened erythrocyte survival and splenic sequestration of 51Cr-labelled erythrocytes uniformly responded with rises in hemoglobin. However, half of the patients with negative splenic sequestration also showed improvement of anemia. Preoperative diagnostic studies failed to predict favorable responses of patients with thrombocytopenia or leukopenia. The classical criteria for the diagnosis of hypersplenism are not applicable in many cases of neoplastic lymphoproliferative disease; splenectomy could have been considered "contraindicated" in most of the patients in this series. We conclude that splenectomy is worth undertaking in patients with lymphoproliferative disease complicated by hematologic depression regardless of marrow findings or the results of other diagnostic studies.

Adult↗
PubMed1989

Biochemical assays of hemoglobin in normal human erythroid clones.

Quantitation of small amounts (2-3 micrograms) of hemoglobin (Hb) was achieved by each of three spectrophotometric techniques. An assay employing benzidine base consistently underestimated Hb at this level and gave a wide scatter of results at higher values. The cyanmethemoglobin method was at the limit of its sensitivity and suffers from the disadvantage of having high optical densities in the blank samples. By contrast, pyridine hemochromogen can be detected accurately with 200 ng of Hb (equivalent of 6,000 mature erythrocytes), and the regression line with this technique virtually passes through the origin. Furthermore, the extinction coefficient of pyridine hemochromogen in the Soret band is 13.5-fold greater than that of cyanmethemoglobin. In normal human erythroid clones, generated in vitro from bone marrow cells, mean cell hemoglobin (MCH) values were determined after various intervals of culture. The MCH after 5, 7, 10, and 14 days were 11.8, 15.8, 26.6, and 34.4 pg, respectively, by the pyridine hemochromogen method. Reaction product was also identified in granulocyte-macrophage clones, presumably reflecting the content of other heme proteins such as catalase and cytochromes. Account must be taken of this non-Hb material in computing true MCH values for erythroid cells.

Bone Marrow Cells↗
PubMed1976

The haematological hazards of autotransfusion.

Fourteen heparinized dogs were autotransfused from 1-5 to 6 times calculated blood volume. Five animals retransfused 12 litres from an intraperitoneal bleed had marked decreases in all cellular elements, haematuria and a large (82 percent) drop in fibrinogen. All these animals died within 12 hours and post-mortem examination revealed evidence of disseminated intravascular coagulopathy. The dogs in which a smaller volume (3-6 litres) was recycled showed similar, but less devastating, changes. Haematocrit and platelet count dropped by a half and fibrinogen by 20 per cent. A leucocytosis of about 30 000/mm3 occurred within 24 hours. Autotransfusion of salvaged blood which was not allowed extravascular tissue contact significantly lessened these adverse effects. We conclude that the risk of cellular destruction and defibrination in large volume intra-operative autotransfusion is significant and must be weighed against its potential benefits in each case, and that red cell and platelet damage results primarily from extravascular tissue contact and is therefore unavoidable.

Animals↗
PubMed1992

Percutaneous transluminal coronary angioplasty in a patient with paroxysmal nocturnal hemoglobinuria.

Paroxysmal nocturnal hemoglobinuria (PHN) is an acquired chronic hemolytic anemia associated with an unusual susceptibility to hemolytic crisis, infection, and venous thrombosis which would be aggravated by a number of factors including surgery. We report a case of PHN undergoing percutaneous transluminal coronary angioplasty and discuss the corresponding perioperative management.

Adult↗
PubMed1992

High-speed rotational angioplasty-induced echo contrast in vivo and in vitro optical analysis.

High-speed rotational angioplasty is being evaluated as an alternative interventional device for the endovascular treatment of chronic coronary occlusions. It has been postulated that this type of angioplasty device may produce particulate debris or cavitations that induce myocardial ischemia. To determine the clinical presence of myocardial ischemia during rotational angioplasty, echocardiographic monitoring for wall motion abnormalities was performed in 9 patients undergoing rotational atheroablation using the Auth Rotablator for 10-sec intervals at 150,000 and 170,000 rpm. No wall motion abnormalities were detected in 5 patients evaluated with transesophageal echocardiography or in 4 patients monitored transthoracically, although AV block developed in one patient. Video intensitometry of the myocardial contrast effect for rotation times ranging from 3 to 20 sec found transient contrast enhancement of the myocardium supplied by the treated vessel. Intensity varied over time with half-time decay between 5.6 and 40 sec, indicating the likelihood of microcavitation. An in vitro model was constructed to measure the cavitation potential of the Auth Rotablator. A burr of 1.25 mm diameter rotating at 160,000 rpm achieves a velocity in excess of the 14.7 m/sec critical cavitation velocity. Testing the device in fresh human blood and distilled water produced microcavitations responsible for the enhanced echo effect, with the intensity and longevity of cavitation more pronounced in blood and proportional to the rotation time and speed. The mean size of the microcavitation bubbles in water was 90 +/- 33 (52-145) microns measured from photographs taken with a copper vapour laser emitting light pulses of 50 nsec duration as light source. The mean velocity of bubbles was found to be 0.62 +/- 0.30 ranging from 0.23 to 1.04 m/sec. It was measured via the motion of the bubbles during 5 laser pulses within 800 nsec. Clearly, microcavitations are associated with enhanced myocardial echo contrast effect.

Angioplasty, Balloon, Coronary↗