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Biomedical subjects

H Silver

Publications and source records attributed to H Silver.

99 records · Page 6Linked to original sources
PubMedDate not supplied

Pretreatment with sedative-hypnotics, but not with nondepolarizing muscle relaxants, attenuates alfentanil-induced muscle rigidity.

STUDY OBJECTIVE: To evaluate and compare the efficacy of various pretreatment agents to attenuate or prevent opioid-induced muscle rigidity using a well-established, previously described clinical protocol. DESIGN: Prospective, controlled, single-blind, partially randomized study. SETTING: Large medical center. PATIENTS: ASA physical status I-III patients undergoing elective surgical procedures of at least 3 hours' duration. INTERVENTIONS: The effect of pretreatment with nondepolarizing muscle relaxants (atracurium 40 micrograms/kg or metocurine 50 micrograms/kg), benzodiazepine agonists (diazepam 5 mg or midazolam 2.5 mg), or thiopental sodium 1 mg/kg on the increased muscle tone produced by alfentanil 175 micrograms/kg was compared with a control group (given no pretreatment). MEASUREMENTS AND MAIN RESULTS: Rigidity was assessed quantitatively by measuring the electromyographic activity of five muscle groups (biceps, intercostals, abdominals, quadriceps, and gastrocnemius). Rigidity also was rated qualitatively by attempts to initiate and maintain mask ventilation, attempts to flex an extremity, and the occurrence of myoclonic movements. Pretreatment with the two nondepolarizing muscle relaxants had no effect on the severe muscle rigidity produced by high-dose alfentanil. Whereas thiopental was only mildly effective, the benzodiazepines midazolam and diazepam significantly attenuated alfentanil rigidity (p < 0.05). CONCLUSION: This study suggests that benzodiazepine pretreatment is frequently, but not always, effective in preventing opioid-induced muscle rigidity.

Abdominal Muscles↗
PubMedDate not supplied

Banked and fresh autologous blood in cardiopulmonary bypass surgery.

When 50 patients having autologous transfusions of two units of blood collected intraoperatively during coronary bypass surgery were compared with 50 patients receiving only homologous donor blood, it was found that a two-unit (20%) decrease in homologous blood usage per case occurred in the group receiving the autologous blood. No decrease occurred in total units of blood used per case. In 15 patients undergoing coronary bypass surgery, in addition to the two units of autolobous blood collected during surgery, two or four units of autologous blood were obtained preoperatively and administered intraoperatively. When four units were collected, the red blood cells were frozen until just prior to surgery. Total blood usage per case remained unchanged but a 4.6 unit (41%) decrease in homologous donor blood usage was noted. Patients phlebotomized preoperatively took 325 mgm of oral iron t.i.d. through the postoperative recovery period. These patients had an average decrease in hematocrit of 4.25 to 4.3 per cent following the final phlebotomy and just prior to surgery.

Administration, Oral↗
PubMedDate not supplied

The use of microaggregate filtration in the prevention of febrile transfusion reactions.

A simplified preparation of leukocyte-poor blood (LPB), employing microaggregate filtration following centrifugation, was compared with three other commonly used and accepted methods. The study group was comprised of 1,283 patients who received a total of 14,561 units of LPB. Of those, 361 patients received 2,235 units of LPB following a primary febrile reaction, and 922 patients received 12,326 units of LPB prophylactically. In both patient populations the microaggregate filtration method proved at least as effective as the inverted spin method and was clearly superior to the buffy coat-poor method in preventing febrile transfusion reactions.

Cell Aggregation↗
PubMedDate not supplied

A simplified method for quality control of deglycerolized erythrocytes.

Quality control to detect inadequately deglycerolized red blood cells can be easily and inexpensively accomplished by suspending the deglycerolized cells in either recipient serum or normal saline in the same way in which the routine crossmatch is performed. In vitro hemolysis is readily and consistently apparent when the residual glycerol exceeds either 2.4% (in saline) or 2.5% (in serum). In contrast to generally held beliefs, the in vivo 24-hour survival of red blood cells with a residual glycerol concentration of up to 2.7% was demonstrated to be 76% of greater, a level which is well above what is usually accepted as adequate.

Blood Transfusion↗
PubMedDate not supplied

Limitations of paternity testing calculations.

A total of 252 black and white trios (mother, child, and putative father) in which the alleged father was known not to be the biological father (BF) were generated from paternity studies. The likelihood of paternity (W) and the paternity index (P) were calculated on the basis of ABO, Rh, MNS, and HLA phenotyping. The results were then reviewed to evaluate the arbitrary limits proposed by a number of states in recent paternity legislation. Two hundred forty-four of 252 non-fathers (NFs) (96.8%) were excluded. Of the 152 white NFs, 147 (96.7%) were excluded; 97 of the 100 blacks (97%) were excluded. Eight NFs could not be excluded by the routinely performed tests. The W value for those eight trios ranged from 1.2 to 98.8 percent. Based on limits proposed in legislation, had the NFs actually been alleged fathers, as many as four of the eight of these men could have had the burden of proving that they were not the BFs.

ABO Blood-Group System↗
PubMedDate not supplied

The impact of a patient education program on directed donations.

The effect of an informational program in which the benefits and disadvantages of directed donations are discussed directly with the prospective recipient of the blood and/or that patient's family was examined during a 20-month period. Data collected for 27 regional Connecticut hospitals that accept directed donations were compared with similar data for Hartford Hospital, an 885-bed tertiary-care facility. The number of directed-donor units (68) collected by the American Red Cross Blood Services for Hartford Hospital during the study period was comparable to the number (average, 62.3) provided for smaller (301-450 beds) institutions in the state. The percentage that directed-donor units drawn for Hartford Hospital represented of the total number of homologous units provided (0.23%) was less than that for any of the categories of hospitals, by size, in the state. Supplying the patient and/or the patient's family, in a personalized manner, with information concerning the advantages and disadvantages of directed as well as of volunteer donor blood can result in a marked overall reduction in the number of directed donations and also serves to reassure those concerned about blood transfusion.

Blood Donors↗
PubMedDate not supplied

Prevention of transfusion-associated cytomegalovirus infection in neonatal patients by the removal of white cells from blood.

The usual methods employed to reduce the risk of transfusion-associated cytomegalovirus (TA CMV) disease have been to transfuse blood or cellular blood components that are CMV antibody-negative or to administer deglycerolized frozen red cells. To determine if the reduction of white cells (WBCs) in blood by filtration will also eliminate TA CMV disease in a high-risk population, 48 surviving very low birth weight (less than 1250 g) neonatal infants born to CMV-seronegative mothers at three participating institutions in the Hartford, Connecticut area and receiving at least one CMV-seropositive blood transfusion were studied. The incidence of TA CMV disease in 26 neonatal patients who received blood prepared by a modified spin-cool-filter technique and in 22 neonatal patients who received blood filtered through a WBC-reduction filter was compared with the incidence of transfusion-associated disease in similar populations reported in other studies. The CMV antibody prevalence of the blood donor population was found to be 37 percent. At the time of discharge of the individual neonatal infants in the population studied, and/or 2 to 6 months later, 47 of the 48 who had undergone transfusion had CMV antibody-negative serologic tests and/or urine culture. The other infant transiently seroconverted because of passive transfer of the antibody. None of the 48 neonatal infants had clinical evidence of CMV infection. This study indicates that WBC reduction of donor blood can reduce and perhaps prevent TA CMV disease in high-risk neonatal patients.

Cytomegalovirus Infections↗
PubMedDate not supplied

A non-computer-dependent prospective review of blood and blood component utilization.

The effect that a prospective review of blood and blood component utilization had during a 1-year period at an 850-bed tertiary-care teaching hospital is reported. The review process, which has been in operation for 18 years, is based on institutionally developed usage guidelines for blood, fresh-frozen plasma (FFP), platelets (Plts), and cryoprecipitate (Cryo). The guidelines were developed by the hospital's Transfusion Medicine Committee. The review is initiated by the transfusion service technical personnel when an order is received. Back-up support is provided, as needed, by physicians on the service or by those pathology residents taking off-hour call. They consult with the ordering physician when questions arise as to the appropriateness of an order as it relates to the patient's clinical situation. Screening values used in the initial evaluation of each order are: hematocrit, less than or equal to 27 percent (0.27) for blood; prothrombin time, greater than or equal to 16 seconds, and/or activated partial thromboplastin time, greater than or equal to 60 seconds, for FFP; bleeding time, greater than or equal to 16 minutes and/or a platelet count of 20 to 100 x 10(3) per mm3 (20-100 x 10(9)/L), as related to clinical conditions, for Pits; and fibrinogen less than or equal to 120 mg per dL (1.2 g/L) for Cryo. Also taken into consideration is the stated clinical indication, which is provided when the requisition is submitted. As a result of the prospective review, orders for blood and/or components for 114 patients were canceled, and 51 patients received 207 blood components that were more appropriate for the clinical situation.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Component Transfusion↗