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Biomedical subjects

R G Strauss

Publications and source records attributed to R G Strauss.

At least 19 recordsLinked to original sources
PubMed1992

Donor reactions during DDAVP-stimulated plasmapheresis.

Donor exposure can be strikingly reduced for patients with classical hemophilia A and von Willebrand's disease when large volumes of potent cryoprecipitated AHF are prepared from donors following DDAVP (1-deamino-8-D-arginine vasopressin) stimulation and automated plasmapheresis--a procedure called "plasma exchange donation." Although this procedure has been reported to be relatively safe for donors, data are limited. Accordingly, we studied 20 donors during 48 procedures using DDAVP (0.3 micrograms/kg IV) followed by 2-3 L plasma collection. Replacement fluid for each initial plasma exchange donation was plasma protein fraction; autologous cryoprecipitate-poor plasma was used for subsequent procedures. Mild reactions, particularly facial flushing, were noted in all 48 procedures. No procedure was discontinued, but four were modified due to either an increased pulse rate (> or = 20/min from baseline) or a fall in systolic or diastolic blood pressure (> or = 20 mm Hg from baseline). No donor was deferred or withdrew from the program. Based on our modest experience, DDAVP stimulated plasma exchange donation appears to be a safe and effective method for collecting large quantities of plasma from which potent cryoprecipitated AHF can be prepared.

Adult↗
PubMed1992

Analysis of venous access for therapeutic plasma exchange in patients with neurological disease.

We retrospectively analyzed our 2-year experience with venous access for 363 therapeutic plasma exchanges in 46 patients with neurological disease, including acute Guillain-Barré syndrome (N = 20), myasthenia gravis (N = 17), and chronic inflammatory demyelinating polyneuropathy (N = 9). Twenty-three patients (50%) completed the planned course of therapy using only peripheral venous access, and 28 central venous catheters were placed in the remaining 23 patients. Patients utilizing central venous access did not undergo a greater number of procedures, but they were more likely to have acute Guillain-Barré syndrome (P < 0.02) or to be hospitalized in a medical intensive care unit (P < 0.01). Three types of central catheters were used, and although our experience was predominantly with 1 type, differences were noted. Only 3% of procedures (3 of 96) done with a Quinton-Mahurkar catheter were associated with a catheter failure, compared to 27% (4 of 15, P < 0.01) with a Hickman catheter and 67% (2 of 3) with a triple-lumen catheter. Life-threatening complications occurred with 3 of 28 (11%) central catheters. To optimize the success of therapeutic plasma exchange using central access, it is critical that hemapheresis personnel advise each patient's primary physician regarding the type of central venous catheter required. Currently, we recommend use of a Quinton-Mahurkar or other dual-lumen hemodialysis catheter.

Adult↗
PubMed1992

Feasibility and success of a single-donor red cell program for pediatric elective surgery patients.

Although the risks of allogeneic blood transfusions are small, it is wise to limit donor exposure whenever possible. A program has been developed in which one donor provided all red cell (RBC) units for each patient awaiting elective surgery. Patients were mostly children who were ineligible for autologous blood donation. Seventy-three patients and 115 donors (mostly parents) entered the program. Of the 115 donors, 90 (78%) were eligible to participate and 25 (22%) were ineligible; 21 were ineligible because of RBC incompatibility. For each of the 73 patients, one eligible donor was selected to donate all RBC units. Preoperative RBC orders were 1 to 2 units for 41 patients and > or = 3 units for 32 patients. Of the 73 donors, 58 (79%) gave all RBC units ordered; 15 (21%) failed to complete all donations, but only 1 because of anemia (hematocrit < 33% [0.33]). Of 73 patients entered, 46 (63%) underwent transfusion, and 27 (37%) did not. Of 46 patients transfused, 38 (83%) received only single-donor RBCs. Thus, the RBC needs of nearly all pediatric elective surgery patients were provided by a single donor for each patient. Single-donor blood programs should be considered for elective surgery patients who are ineligible for autologous blood donation and who would otherwise be exposed to multiple donors.

Blood Component Transfusion↗
PubMed1979

Prolonging paracervical block anesthesia: addition of dextran to 2-chloroprocaine.

Forty parturient women received paracervical block (PCB) anesthetics during labor with 2-chloroprocaine (2-CP) and epinephrine in either normal saline or dextran. Thirty-six patients were though to have adequate anesthesia. Nineteen patients who recived 2-CP in saline had a mean duration of anesthesia lasting 55.4 min; one fetus developed post-PCB bradycardia. Seventeen patients who received 2-CP in dextran had a mean duration of anesthesia lasting 72.7 min; no fetal bradycardia was observed following PCB. Neonatal depression, expressed by 1 and 5 min Apgar scores below seven, was not observed in either group. The addition of dextran to 2-CP significantly prolongs the duration of PCB anesthesia and does not appear to compromise the fetus. The pain relief provided by a single PCB with 2-CP in dextran is still relatively short and would not persist throughout the active phase of labor in most parturient women.

Adolescent↗
PubMed1979

An intrinsic coagulation pathway inhibitor in a 3-year-old child.

An intrinsic coagulation pathway inhibitor with acitivty against factor XI was detected in the plasma of a 3-year-old child, following a respiratory infection. The inhibitor was present transiently, but it was clinically significant and was manifiested by extensive bruises. Abnormalities of clotting and the bruising tendency disappeared simultaneously without treatment before the inhibitor could be definitively characterized. It was possibly the consequence of an adenovirus infection, as an elevated adenovirus titer was demonstrated in the patient's blood. It is possible that inhibitors of this type are more common sequelae of viral infections than realized, and perhaps a systematic effort should be made to detect them and to define their etiology and mechanism of action.

Adenovirus Infections, Human↗
PubMed1979

In vitro comparison of the erythrocyte sedimenting properties of dextran, hydroxyethyl starch and a new low-molecular-weight hydroxyethyl starch.

A low-molecular-weight preparation of hydroxyethyl starch (LMW-HES) may serve as a desirable substitute for the erythrocyte sedimenting agents presently employed to improve neutrophil yields in centrifugation and gravity leukapheresis. The cell-separating and erythrocyte-sedimenting properties of LMW-HES, assessed in vitro by the recovery of various blood cells in plasma supernatant fluids, were similar to those of the higher-molecular-weight hydroxyethyl starch in current use and to dextran under a variety of conditions. These data predict success for LMW-HES as a sedimenting agent in leukapheresis and recommend that it be evaluated in clinical trials.

Blood Platelets↗
PubMed1979

Epilepsy and pregnancy. Serum thyroxine levels during phenytoin therapy.

Blood levels of phenytoin, total thyroxine, and free thyroxine were determined in 10 epileptic women during and following pregnancy. Although total thyroxine concentrations of phenytoin-treated subjects were significantly lower than control values, pregnancy did not appear to diminish the relative increase in total thyroxine seen in normal pregnancy. Free thyroxine concentrations, which were equally depressed at all test times, remained at low euthyroid levels during pregnancy. Following delivery, 3 patients developed free thyroxine levels below 1.0 ng/100 ml. Phenytoin dosage was increased to improve seizure control but produced relatively low blood levels during pregnancy. Following delivery, phenytoin dosage was slightly decreased but produced a significant increase in phenytoin blood levels. The potential effects of phenytoin-related changes in maternal and fetal thyroxine levels are discussed.

Abnormalities, Drug-Induced↗
PubMed1979

Complement in cystic fibrosis.

Quantitative and functional assessments were made of both the classical and alternative pathways of complement activation in sera from 23 patients with cystic fibrosis. The classical pathway functioned similarly in patients and controls as measured by CH50 titre. Alternative pathway function, initiated in patient sera by incubation with inulin, was equal to that of controls as determined by cleavage of Factor B and C3, and by the consumption of terminal components. Factor B, however, was more readily activated in patient than in control sera. This rapid alteration of Factor B did not lead to accelerated or more extensive activation of the terminal complement components via the alternative pathway when assessed by C3 cleavage and the consumption of terminal components. Thus, a complement deficiency was not found. The importance of the easily activated Factor B is undefined.

Adolescent↗
PubMed1978

Therapeutic neutrophil transfusions: are controlled studies no longer appropriate?

The aim of this review is to determine whether sufficient data have been reported to completely define the role and/or efficacy of neutrophil transfusions in the treatment of specific types of infections in neutropenic patients. Data were collected from the literature pertaining to the use of therapeutic neutrophil transfusions. When only the controlled studies are analyzed, a significant therapeutic advantage for neutrophil transfusions plus antibiotics can be demonstrated when this treatment is compared to treatment with antibiotics alone. However, the controlled studies are vulnerable to critical analysis, and several points argue against applying data from these studies indiscriminately to all infected, neutropenic patients encountered in practice. Moreover, it is apparent when all of the data (controlled and uncontrolled studies) are tabulated, that information is insufficient to establish the efficacy of neutrophil transfusions as treatment for most types of specific bacterial infections. Several problems exist in the wholesale acceptance of liberal transfusion policies, and the benefits that justify continued controlled studies deserve emphasis.

Agranulocytosis↗
PubMed1978

Iron deficiency, infections, and immune function: a reassessment.

Many physicians believe that patients with iron deficiency have an increased susceptibility to infections. Data in the literature, however, are contradictory, and in many instances the reports are vulnerable to critical review. Literature available through 1976 was analyzed in an attempt to define possible relationships between infections, immune function, and states of iron imbalance, both iron deficiency and overload. Critical points that must be considered for an accurate interpretation were emphasized. It seems clear that the inflammatory response, when assessed by skin reactivity, is diminished in iron deficiency. The precise molecular defect remains undefined, but the abnormality is detected by several assays measuring cell-mediated immunity. Normal function is usually restored following iron repletion.

Anemia, Hypochromic↗
PubMed1978

Oxidative metabolism in cord-blood polymorphonuclear leucocytes.

Polymorphonuclear leucocytes were isolated from cord-blood samples collected from healthy, term infants. Oxidative metabolism was assessed in these cells by hexose monophosphate shunt activity and chemiluminescence. Basal levels of oxidative metabolism were spontaneously increased in resting (nonphagocytic) cord-blood cells as compared to adult controls. As a response to phagocytosis, cord-blood cells initiated the expected increase in oxidative metabolism and reached normal peak values of activity. However, these cells were unable to maintain the high metabolic rate for as long a time as adult controls. This aberration of leucocyte function may indicate a deficiency of metabolic reserve and could be related to the increased susceptibility of newborns to bacterial infections.

Fetal Blood↗
PubMed1978

Status epilepticus in pregnancy: effect of phenytoin malabsorption on seizure control.

In the second trimester of pregnancy in a 26-year-old woman, marked exacerbation of epileptic seizures occurred with somatomotor status epilepticus. The oral requirement of phenytoin varied, and up to 1,200 mg per day were needed to maintain a therapeutic plasma concentration during the second trimester. Intestinal malabsorption was shown to be a causal factor; 56 percent of the daily oral dose of phenytoin was found in the stool. Late in pregnancy and postpartum, therapeutic plasma concentrations of phenytoin were maintained with decreased daily oral doses. Intestinal absorption improved postpartum.

Administration, Oral↗
PubMed1978

Hematologic effects of phenytoin therapy during pregnancy.

Serum folate and plasma phenytoin concentrations were measured in 10 epileptic gravidas who did not receive folate supplementation. Mean serum folate concentration averaged 5.0 ng/ml during the second and third trimesters of pregnancy but significantly decreased to 2.9 ng/ml during nonpregnant evaluation 1 to 12 months following delivery. No patient exhibited anemia or macrocytosis suggestive of cellular folate deficiency either during or following pregnancy. Although phenytoin dosage remained relatively constant, plasma phenytoin concentrations during pregnancy were significantly lower than nonpregnant concentrations. The improvement in folate status observed during pregnancy may be related to lowered plasma phenytoin concentrations.

Carotenoids↗