Biomedical subjects

M J Randels

Publications and source records attributed to M J Randels.

17 recordsLinked to original sources

PubMed1999

Frequency of immediate adverse effects associated with therapeutic apheresis.

BACKGROUND: Therapeutic apheresis was found to be reasonably safe in prior studies using instruments that are now largely obsolete. The incidence of adverse effects with current instruments and techniques has not been assessed in a large multicenter study. STUDY DESIGN AND METHODS: A survey was conducted in 1995 using a uniform questionnaire that asked about 32 specific events but excluded transient paresthesia and mild vasovagal events. Eighteen centers returned 3429 responses concerning 125 to 500 therapeutic apheresis procedures per center. RESULTS: Two hundred forty-two adverse events were reported in 163 procedures (4.75% of all procedures; 6.87% of first-time procedures and 4.28% of repeat procedures). The numbers (incidence) of selected specific events were transfusion reaction, 56 (51 in plasma exchange [PE] with plasma replacement) (1.6%); citrate-related nausea and/or vomiting, 41 (1.2%); systolic blood pressure <80 mmHg, 34 (1.0%); vasovagal nausea and/or vomiting, 17 (0.5%); pallor and/or diaphoresis, 16 (0.5%); pulse >120, 14 (0.4%); respiratory distress, 9 (0.3%); tetany or seizure, 9 (0.2%); and chills or rigors, 6 (0.2%). Rates for other specific events were < or =0.1 percent. Vasovagal phenomena were more frequent in procedures done in neurologic patients than in those done in hematology or oncology patients (p = 0.011) or renal or rheumatic patients (p = 0.038). Procedure-specific rates were red cell exchange, 8 (10.26%) of 78; PE (plasma), 89 (7.81 %) of 1140; PE (no plasma), 42 (3.35%) of 1255; leukapheresis, 4 (5.71%) of 70; plateletpheresis, 0 of 18; and autologous peripheral blood progenitor cell collection, 11 (1.66%) of 664. Three deaths were reported; all were attributed to primary disease. CONCLUSION: Therapeutic apheresis procedures are relatively safe, with a 4.75-percent overall incidence of mostly reversible adverse effects. Among the most commonly performed procedures, the risk is higher for blood component exchanges, especially if allogeneic red cell or plasma transfusion occurs, and lower for peripheral blood progenitor cell collection.

Anticoagulants↗

PubMed1998

Frequency of immediate adverse effects associated with apheresis donation.

BACKGROUND: Apheresis donation is considered safe, but the incidence of adverse effects has not been determined in a large multicenter series of donations with modern instruments. STUDY DESIGN AND METHODS: The Hemapheresis Committee of the American Association of Blood Banks devised a uniform questionnaire that asked about 32 specific adverse effects. Transient paresthesia and mild vasovagal events were excluded. A survey was conducted in 1995; 17 centers returned 19,611 responses concerning 250 to 2,000 consecutive apheresis donations per center. RESULTS: Six hundred adverse effects were reported in 428 donations (2.18% of donations). Pain or hematoma at a venipuncture site was the most common response (1.15% of donations); only 203 donations had other (nonvenipuncture) adverse effects (1.04%). Total and nonvenipuncture rates were, respectively, 4.84 and 2.92 percent for 2,295 first donations and 1.78 and 0.77 percent for 17,303 repeat donations (p < 0.001). Rates of nonvenipuncture symptoms in first and repeat donations were, respectively, citrate-induced nausea and/or vomiting, 0.87 and 0.27 percent; tetany, 0.09 and 0.04 percent; pallor and/or diaphoresis, 1.87 and 0.32 percent; vasovagal nausea and/or vomiting, 0.87 and 0.13 percent; syncope and/or seizure, 0.39 and 0.04 percent; and chills and/or rigors, 0.31 and 0.01 percent. The overall rate of donor unconsciousness was 0.08 percent. Hemolysis was reported twice. Clotting or leakage occurred in 0.08 percent of donations, and inability to return blood occurred in 0.16 percent. No life-threatening adverse effects were reported. Procedure-specific nonvenipuncture rates were 1.05 percent of 17,584 platelet donations, 0.67 percent of 594 white cell donations, and 0.37 percent of 1,354 plasma donations. Center-specific rates varied from 0.32 to 6.81 percent of donations for total adverse effects and from 0.11 to 2.92 percent of donations for nonvenipuncture events. CONCLUSION: Apheresis donation is a safe undertaking, suitable for voluntary blood donors, with a very low risk of serious adverse effects. The risk of unconsciousness is lower than that found in many studies of whole-blood donation.

Blood Component Removal↗

PubMed1997

Fingerstick blood samples in platelet donor screening: reliability and impact on predict yield programs.

Although widely used, the reliability of fingerstick platelet counts for determining donor eligibility and for use with plateletpheresis predict yield programs has not been established. We compared platelet counts obtained from fingerstick vs. venous samples in several aspects of apheresis platelet collection. Analysis of 25 paired fingerstick and venous predonation samples demonstrated a poor correlation between platelet counts (r2 = .43), with fingerstick counts having a 20% lower mean value (P < .05). The effect of using fingerstick vs. venous predonation platelet counts with apheresis instrument predict yield calculations to obtain target yields was determined. Mean yields collected using fingerstick/predict yield were 12% (Fenwal CS3000 PLUS) and 15% (Haemonetics MCS+) higher than venous/predict yield units (P < .05). The coefficients of variation (CV) of fingerstick/predict yield and venous/predict yield collections were comparable (15% vs. 14% [CS3000] and 23% vs. 21% [MCS+], respectively), indicating that possible differences in accuracy between fingerstick and venous platelet counts had little effect on the variability of predict yield collections. A retrospective analysis of the CV of 100 fingerstick/predict yield units vs. 100 units collected by processing standard volumes showed no difference: 22% vs. 20% (F = 0.99, CS3000), and 22% vs. 24% (F = 0.89, MCS+), respectively. We conclude that fingerstick platelet counts are systematically lower and correlate poorly with venous counts, though their use seldom results in false disqualification of donors. We also conclude that fingerstick count/predict yield collections do not produce more consistent yields of platelets than standard volume collections.

Blood Donors↗

PubMed1996

Providing leukocyte-reduced platelets using the CS-3000 PLUS.

Reducing leukocyte (WBC) contamination of platelet (PLT) concentrates diminishes some adverse effects associated with transfusions. To provide WBC-reduced PLTs, we initiated a program using bedside filtration. However, the inability to easily quantitate WBC removal and PLT loss at the bedside prompted us to perform filtration in the blood bank. To establish optimal methods, production of WBC-reduced PLTs using the CS-3000 PLUS was studied in three phases, during which technical modifications were made. During phase 1, prestorage WBC reduction was performed using the PALL LRF-10H filter, sterilely connected. WBC reduction was satisfactory, but PLT loss was excessive. During phase 2, the PLT-30 collection chamber and Fenwal Closed System Apheresis Kit with Integral Sepacell Leukocyte Reduction Filter were used. PLT yields were improved, but now WBC contamination was excessive. During phase 3, the interface offset was reduced from 10 to 6, and both PLT yields and WBC reduction were satisfactory. Using this final method (CS-3000 PLUS, PLT-30 collection chamber, integral filter and offset setting of 6), the mean PLT yield per unit is 4.29 x 10(11) (N = 1,146), and the mean WBC contamination is 0.50 x 10(6) (N = 32).

Blood Banks↗

PubMed1995

Efficacy and safety of plateletpheresis by donors with low-normal platelet counts.

Our practice is to defer donors with blood platelet (PLT) counts of < 180 x 10(9)/L because PLT yields are low, when compared to PLT units collected from donors with higher counts. In an attempt to minimize deferral, we determined whether 33 donors, who repeatedly demonstrated low-normal PLT counts (150-180 x 10(9)/L) on multiple occasions during the prestudy period. might safely donate satisfactory apheresis PLT units simply by extending the apheresis collection time by 20 min (men) and 40 min (women). Repeat plateletpheresis procedures were scheduled at > or = 28-day intervals. The mean PLT yield (N = 92) was 5.8 x 10(11) with 97% of units containing > or = 4.0 x 10(11) PLTs. Although donors entered the study only after they had repeatedly exhibited predonation PLT counts of < 180 x 10(9)/L, PLT counts were not always below this level at the time of study collections. However, analyzing only donations with true predonation PLT counts of < 180 x 10(9)/L (N = 35), the mean PLT yield was excellent-5.4 x 10(11) with 97% of units containing > or = 4.0 x 10(11) PLTs. The average fall in donor blood PLT counts (pre-vs. postdonation) was 36%, with only ten of 99 postdonation counts being < 100 x 10(9)/L; the lowest was 69 x 10(9)/L. Thus, extending the apheresis collection time permitted donors who in the past were routinely deferred because of low PLT counts to safely donate satisfactory PLT units.

Blood Donors↗

PubMed1994

Preoperative autologous donation: surgery clinic staff knowledge/attitudes. Preoperative Autologous Blood Donation Study Group.

Preoperative autologous blood donation (PABD) is both under- and overused. Although the decision to order PABD lies with the surgeon, it is quite likely that other surgery clinic personnel influence patient acceptance and enrollment into PABD programs. Accordingly, we measured knowledge, attitudes, and the referral practice of clinic personnel pertaining to PABD. We administered a questionnaire to 102 nurses and 33 clerks working in surgery clinics at three university medical centers--one center in an area with a high incidence of AIDS and two centers in areas of low incidence of AIDS. Knowledge of PABD was poor when assessed by six questions. Only 6% each of nurses and clerks answered all questions correctly; 55% of nurses and 54% clerks missed three or more of the six questions. Surprisingly, no differences (P > .05) in knowledge deficits were noted when personnel from high and low AIDS areas were compared--indicating an overall need for education about PABD. In general, attitudes about PABD were positive, as most respondents (63%) gave favorable answers. Clinic personnel from the high AIDS area had even more favorable attitudes (P = .02). Because of these favorable attitudes, it seems likely that educational programs dealing with PABD would be readily accepted by clinic personnel. Greater knowledge should enhance the effectiveness of clinic staff in identifying, counseling, and referring eligible patients for this service.

Acquired Immunodeficiency Syndrome↗

PubMed1994

Treatment of severe cardiac allograft rejection with extracorporeal photochemotherapy.

Two patients were treated with photopheresis for marked cardiac allograft rejection with hemodynamic compromise that had become unresponsive to standard therapy. Multiple episodes of rejection had occurred, and initial response to standard therapy was favorable. However, progressive deterioration was documented by serial endomyocardial biopsies, fever, congestive heart failure, and abnormal cardiac catheterization findings. In the absence of retransplantation, death seemed imminent. Photopheresis was begun. Both patients received oral 8-methoxypsoralen and > or = 5 x 10(9) mononuclear cells were collected, treated with ultraviolet light A for 1.5 hours, and were reinfused. One procedure was performed weekly x4 and then monthly x5. Responses were striking with rapid loss of fever, improvement in exercise tolerance, normalization of cardiac hemodynamics, and improvement in endomyocardial biopsies. Although our experience with these two patients is anecdotal, photopheresis merits further study as treatment for severe cardiac allograft rejection.

Adult↗

PubMed1994

A statistical model for estimating donor postdonation platelet counts after plateletpheresis.

BACKGROUND: To avoid the need, in serial apheresis donors, either to delay plateletpheresis until a predonation platelet count is completed or to obtain a postdonation count after each procedure, a statistical model has been developed to predict the postdonation platelet count from the donor predonation platelet count, weight, and hematocrit. STUDY DESIGN AND METHODS: Predonation and postdonation platelet counts were measured in two groups of approximately 100 consecutive donors (Group A to test the model and Group B to validate it), and the postdonation counts were calculated with the model. Using stepwise multiple linear regression from donor data, estimated postdonation platelet counts were found to be comparable to the postdonation platelet counts actually measured. RESULTS: Estimated postdonation platelet counts x 10(9) per L (mean +/- SD) for each group, respectively, were Group A, 195 +/- 35, versus actual platelet counts of 195 +/- 39 (p = 0.43), and Group B, 183 +/- 36, versus actual platelet counts of 189 +/- 34 (p = 0.14). Sensitivity and specificity, respectively, were Group A, 57 and 99 percent and Group B, 62 and 99 percent. CONCLUSION: For most serial apheresis donors, application of this predictor model should preclude the need to obtain an extra postdonation platelet count.

Blood Donors↗

PubMed1994

Concurrent comparison of the safety of paid cytapheresis and volunteer whole-blood donors.

BACKGROUND: Historically, paid blood donors were found to transmit hepatitis at higher rates than volunteers. In those older studies, paid donors frequently were recruited from prisons or slum areas--a finding consistent with the belief that monetary payment in itself did not necessarily lead to the high-risk status of commercial blood. Instead, it was the population base from which the donors were recruited that was important. STUDY DESIGN AND METHODS: Today, cytapheresis donors are in great demand. Because payment is one incentive that might entice donors to undertake the increased commitment of repeated cytapheresis donation, the results were studied of infectious disease history and laboratory testing performed concurrently in 917 volunteer whole-blood donors and 1240 paid cytapheresis donors, who were enrolled in distinct programs at the DeGowin Blood Center from October 7, 1987, through November 30, 1990. RESULTS: When first, repeat, and overall donations made by these donors were evaluated separately, paid cytapheresis donors were found to exhibit no increase in infectious disease history or test results beyond those of volunteer whole-blood donors. CONCLUSION: Thus, paid cytapheresis donors, when managed within a formal program, should not necessarily be presumed to be more dangerous than volunteers, from an infectious disease aspect. However, definitive proof of safety (comparison of transfusion-transmitted infection rates in two groups of patients receiving blood components exclusively from either paid cytapheresis or volunteer donors) was not pursued by long-term follow-up studies.

Blood Donors↗

PubMed1993

Comparison of plateletpheresis with a standard and an improved collection device.

A blood cell separator with a specialized separation chamber ([TNX-6]CS-3000 Plus) was developed for the collection of platelet concentrates with higher platelet yields and lower white cell contamination than obtained with the standard blood cell separator (CS-3000). To compare these devices, normal donors were scheduled for paired plateletpheresis procedures spaced 4 weeks apart, with one procedure using the CS-3000 Plus and the other using the CS-3000. Overall, the platelet yield per unit (mean +/- SEM) was 4.3 +/- 0.1 x 10(11) with the CS-3000 Plus versus 3.7 +/- 0.1 x 10(11) with the CS-3000 (p < 0.001), and the white cell contamination per unit (mean +/- SEM) with the former was 2.4 +/- 0.7 x 10(6) versus 84.1 +/- 21.1 x 10(6) with the latter (p < 0.001). The sequence of procedures (i.e., the order in which the devices were paired) was selected randomly, and similar results were found regardless of sequence. When donors with predonation platelet counts of > or = 200 x 10(9) per L (n = 21) were studied separately, 76 percent of the collections by the CS-3000 Plus contained > or = 4 x 10(11) platelets versus 34 percent of those by the CS-3000 (p < 0.01), and 93 percent of the collections by the former contained < 5 x 10(6) white cells (69% contained < 1 x 10(6)) versus 0 percent of those by the latter (p < 0.01). Thus, platelet collections with the TNX-6 chamber consistently demonstrated high platelet yields and strikingly low white cell contamination--qualities that justify converting standard devices to devices with a TNX-6 chamber.

Cell Separation↗

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

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↗

PubMed1991

Efficacy and safety of Fenwal CS-3000 plateletpheresis performed at a rapid donor blood flow rate: rapid plateletpheresis with Fenwal CS-3000.

Results of 3,214 plateletpheresis procedures, using the Fenwal CS-3000 cell separator, were reviewed to determine the effects on performance when the donor blood flow rate was increased by 30% (i.e., to 65 ml/min instead of 50 ml/min). Ninety-two percent (2,962 of 3,214) of procedures completed the rapid flow protocol, and results were compared with those reported by others using the more conventional blood flow rates of 32-55 ml/min. When the rapid flow procedure was used, mean platelet yields (4.07 x 10(11)) and leukocyte contamination (2.65 x 10(8)) were satisfactory, and major donor reactions were infrequent (0.6% of procedures). Thus, CS-3000 plateletpheresis can be performed at a relatively rapid, donor blood flow rate of 65 ml/min to shorten the procedure and make it more appealing to donors.

Blood Flow Velocity↗

PubMed1991

Concurrent comparison of the Cobe Spectra and Fenwal CS3000 for the collection of peripheral blood mononuclear cells for autologous peripheral stem cell transplantation.

Hematopoietic stem cells, collected by leukapheresis from peripheral blood, can be used as an alternative to autologous bone marrow transplantation following high-dose chemotherapy as treatment of several malignancies. We compared the ability of the Cobe Spectra and the Fenwal CS3000 to collect peripheral blood mononuclear cells (MNC) for autologous peripheral blood stem cell transplantation. Ten patients experienced repeated leukapheresis (10 L blood processed per procedure) using both instruments. Procedures were alternated between the two until a total of 7 x 10(8) MNC/kg was collected. Data from 61 Spectra and 50 CS3000 collections were analyzed. The yield (mean per procedure) of nucleated cells (NC) and MNC was higher (P less than .005) with the Spectra (0.77 x 10(10) NC and 0.54 x 10(10) MNC) than with the CS3000 (0.59 x 10(10) NC and 0.40 x 10(10) MNC). However, colony forming units (CFU-GM) were not different (P greater than .05) for Spectra (0.92 x 10(4)) and Fenwal (0.65 x 10(4) collections. Platelet contamination was lower (P less than .001) with the Spectra (2.2 x 10(11)) than the CS3000 (5.0 x 10(11)). This correlated with a higher patient blood platelet count immediately following Spectra collections (117 x 10(9)/L) versus the CS3000 (86 x 10(9)/L). Using the methods described, the Spectra product contained greater yields of NC and MNC with less platelet contamination than did the CS3000.

Antineoplastic Agents↗

PubMed1991

The Fenwal CS3000 inline pack is acceptable for donor blood sampling.

A blood sampling pack is available on closed system apheresis kits for the Fenwal CS3000 blood cell separator to facilitate same day donor testing while maintaining the closed system. Conceivably, the accuracy of complete blood counts (CBC) performed using pack samples might be compromised by clotting in the pack, by adherence of blood cells to the inner surface of the pack, or by dilution of the sample with priming fluid--should it inadvertently contaminate the pack. We studied paired blood samples collected simultaneously via the pack and a separate venipuncture in 17 donors. When collected properly, CBC values from pack and vein were nearly identical. Even when purposely contaminated with saline, pack values were lowered only slightly. Thus, the inline pack permits accurate sampling of donor blood for CBC while maintaining a closed system.

Artifacts↗

PubMed1991

Granulocyte collection.

Techniques for collecting granulocytes for transfusion either to neutropenic patients or to neonates are described. Currently, the best granulocyte concentrates are prepared using continuous-flow centrifugation leukapheresis of steroid-stimulated donors in the presence of pentastarch. Donor reactions are mild and are similar to those expected with automated plateletpheresis.

Flow Cytometry↗

PubMed1991

Comparison of muscle sympathetic responses to hemorrhage and lower body negative pressure in humans.

We compared changes in muscle sympathetic nerve activity (SNA) during graded lower body negative pressure (LBNP) and 450 ml of hemorrhage in nine healthy volunteers. During LBNP, central venous pressure (CVP) decreased from 6.1 +/- 0.4 to 4.5 +/- 0.5 (LBNP -5 mmHg), 3.4 +/- 0.6 (LBNP -10 mmHg), and 2.3 +/- 0.6 mmHg (LBNP -15 mmHg), and there were progressive increases in SNA at each level of LBNP. The slope relating percent change in SNA to change in CVP during LBNP (mean +/- SE) was 27 +/- 11%/mmHg. Hemorrhage of 450 ml at a mean rate of 71 +/- 5 ml/min decreased CVP from 6.1 +/- 0.5 to 3.7 +/- 0.5 mmHg and increased SNA by 47 +/- 11%. The increase in SNA during hemorrhage was not significantly different from the increase in SNA predicted by the slope relating percent change in SNA to change in CVP during LBNP. These data show that nonhypotensive hemorrhage causes sympathoexcitation and that sympathetic responses to LBNP and nonhypotensive hemorrhage are similar in humans.

Adult↗