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Pearl Toy

Publications and source records attributed to Pearl Toy.

13 recordsLinked to original sources
PubMed2005

Acute isovolemic anemia impairs central processing as determined by P300 latency.

OBJECTIVE: Acute anemia slows the responses to clinical tests of cognitive function. We tested the hypothesis that these slowed responses during acute severe isovolemic anemia in healthy unmedicated humans result from impaired central processing. METHODS: A blinded operator measured the latency of the P300 peak in nine healthy volunteers at each volunteer's baseline hemoglobin concentration (Hb), and again after isovolemic hemodilution to Hb 5 g/dL. At both Hb concentrations, the P300 latency was measured twice: with the blinded subject breathing air or 100% oxygen, administered in random order. RESULTS: Anemia increased P300 latency significantly from baseline values (P < 0.05). Breathing oxygen during induced anemia resulted in a P300 latency not different from that at baseline when breathing air (P = 0.5) or oxygen (P = 0.8). CONCLUSIONS: Impaired central processing is, at least in part, responsible for the slowed responses and deficits of cognitive function that occur during acute isovolemic anemia at Hb 5-6 g/dL. SIGNIFICANCE: The P300 latency appears to be a potential measure of inadequate central oxygenation. In healthy young adults with acute anemia, erythrocytes should be transfused to produce Hb>5-6 g/dL. As a temporizing measure, administration of oxygen can reverse the cognitive deficits and impaired central processing associated with acute anemia.

Adult↗
PubMed2005

Transfusion related acute lung injury: a pediatric perspective.

Transfusion-related acute lung injury (TRALI) is the leading cause of transfusion-associated mortality. TRALI occurs in children and adults, but the syndrome has not been reviewed from a pediatric perspective. We reviewed the literature on TRALI from a pediatric perspective. TRALI has been documented in pediatric patients, especially in the setting of hematologic malignancy. Additional TRALI cases have been reported in pediatric patients with a variety of diagnoses. TRALI is likely to be much more common than previously appreciated in the pediatric patient population. TRALI should be considered in the differential diagnosis of all pediatric patients who develop new acute lung injury (ALI) or acute respiratory distress syndrome (ARDS) during or within six hours of a blood product transfusion. When a case of TRALI is suspected, a transfusion reaction report to the blood bank is important to initiate the investigation and identify the implicated donor.

Adolescent↗
PubMed2005

Transfusion-related acute lung injury: definition and review.

BACKGROUND: Transfusion-related acute lung injury (TRALI) is now the leading cause of transfusion-associated mortality, even though it is probably still underdiagnosed and underreported. NATIONAL HEART, LUNG, AND BLOOD INSTITUTE ACTION: The National Heart, Lung, and Blood Institute convened a working group to identify areas of research needed in TRALI. The working group identified the immediate need for a common definition and thus developed the clinical definition in this report. MAJOR CONCEPTS IN THE DEFINITION: The major concept is that TRALI is defined as new acute lung injury occurring during or within 6 hrs after a transfusion, with a clear temporal relationship to the transfusion. Also, another important concept is that acute lung injury temporally associated with multiple transfusions can be TRALI, because each unit of blood or blood component can carry one or more of the possible causative agents: antileukocyte antibody, biologically active substances, and other yet unidentified agents. RECOMMENDATION: Using the definition in this report, clinicians can diagnose and report TRALI cases to the blood bank; importantly, researchers can use this definition to determine incidence, pathophysiology, and strategies to prevent this leading cause of transfusion-associated mortality.

Blood Transfusion↗
PubMed2005

Extracellular potassium concentrations in red blood cell suspensions after irradiation and washing.

BACKGROUND: Extracellular potassium concentration [K(+)e] increases with duration of red blood cell storage. Sometimes red blood cells (RBC) are washed before transfusion to infants to reduce [K(+)e] of these components. AABB standards permit storage of washed RBCs at 4 degrees C for 24 hours. The [K(+)e] of washed RBCs during storage is not known. Experiments were performed to provide those data. STUDY DESIGN AND METHODS: One day after outdating, 26 RBC units were washed without irradiation or before or after irradiation (25 Gy), and [K(+)e] was measured for 24 hours. [K(+)e] was measured also immediately before transfusion of 29 nonoutdated irradiated and washed RBC units. RESULTS: After washing, [K(+)e] increased in a time-dependent fashion. [K(+)e] increased more rapidly in preparations of irradiated than nonirradiated RBCs. [K(+)e] was less after washing after irradiation (1.6 +/- 0.3, 2.4 +/- 0.3, 3.0 +/- 0.3, 3.6 +/- 0.3. 4.2 +/- 0.4, 5.3 +/- 0.5, 8.6 +/- 1.0, and 14.3 +/- 1.3 mEq/L at 0, 1, 2, 3, 4, 6, 12, and 24 hr; mean +/- SD) than washing before irradiation (p < 0.001). The increase in [K(+)e] during the first 6 hours after washing after irradiation was linear (0.61 +/- 0.08 mEq K(+)/L/hr). The probability of a unit of RBCs having a [K(+)e] greater than 5 mEq per L is 0.0 to 0.2 percent 3 hours after washing irradiated RBCs and 0.0 to 1.1 percent 6 hours after washing nonirradiated RBCs. CONCLUSIONS: [K(+)e] increases after washing irradiated and nonirradiated packed RBCs. After irradiation and washing, the [K(+)e] for the initial 6 hours can be predicted from the [K(+)e] immediately after washing. There is a low probability that a unit of RBCs would have a [K(+)e] greater than 5 mEq per L during 6 hours of storage at 4 degrees C after washing if the cells are not irradiated and for 3 hours if the cells are irradiated.

Blood Preservation↗
PubMed2005

Designing and testing a computer-based screening system for transfusion-related acute lung injury.

Computer-based systems can detect underreported adverse events. We hypothesized that a system could be designed to detect potential or unreported cases of transfusion-related acute lung injury (TRALI). We developed and tested a computer screening system using retrospective computer blood gas data after transfusions during a 45-day period at a tertiary care academic hospital. The program identified cases of posttransfusion hypoxemia. Medical records of identified cases were reviewed to diagnose TRALI. During the 45-day period, 820 patients received 6,888 blood products. Seven cases of TRALI were diagnosed, whereas only 2 had been reported. The system had 99% accuracy and 26% positive predictive value for detecting potential TRALI. Computer screening finds more cases of TRALI than are reported voluntarily, and a prospective study using this system is feasible and needed to validate this method of detecting this important adverse transfusion reaction.

Adolescent↗
PubMed2005

A procedure for rapid issue of red cells for emergency use.

CONTEXT: A College of American Pathologists Q-Probe revealed that the median turnaround times for emergency requests for red blood cells from the operating room were 30 minutes to release of cells from the blood bank and 34 minutes to delivery to the operating room. These times may not be adequate to permit the red cells to provide sufficiently rapid delivery of oxygen in massively bleeding patients. OBJECTIVE: To improve the time from emergency request for red cells to delivery to the operating room. DESIGN: A new emergency issue program was implemented for only the operating rooms; emergency issue to all other hospital locations remained unchanged. Six units of group O Rh-negative red blood cells (RBCs) are maintained in the blood bank in a separate basket with transfusion forms containing the unit numbers and expiration dates and a bag with one blood tubing segment from each unit. The times to issue and to delivery to the operating room suite were compared with time to issue of 2 group O Rh-negative RBCs for other hospital locations using the older system during the same time period and with the time to issue of 2 units to all other hospital locations during the preceding 2 years. SETTING: A university hospital. MAIN OUTCOME MEASURES: Time between emergency request for red cells and delivery to the operating room. RESULTS: The time between blood bank notification and arrival in the operating room of the 6 units of RBCs was significantly shorter than the time required to just issue (not including delivery time) 2 units of RBCs to other hospital locations. With the new procedure, 82% of units issued reached the operating room within 2 minutes of request, 91% arrived within 3 minutes, and 100% arrived within 4 minutes. These percentages are significantly higher than those for only issue of blood (without delivery) using the older issuing procedure for all hospital locations during the previous 2 years (37%, 49%, and 66%, respectively; P = .007, .009, and .02, respectively) and for other locations during the same 7-month period (29%, 46%, and 73%, respectively; P = .004, .01, and .09, respectively). Time (mean [95% confidence interval]) from blood bank notification to delivery of RBCs to the operating room suite (2.1 [1.6-2.6] minutes, of which approximately 50-60 seconds is attributable to delivery time) was less than issue times (not including delivery times) using the older issuing procedure for other hospital locations during the same period (4.1 [3.1-5.0] minutes; P = .007). CONCLUSIONS: An emergency issue procedure can be used to issue several units of RBCs within 1 minute and have them delivered to the operating room within 2 minutes while maintaining sufficient controls and providing required information to satisfy patient and blood bank requirements.

Blood Banks↗
PubMed2004

Recipients of blood from a donor with multiple HLA antibodies: a lookback study of transfusion-related acute lung injury.

BACKGROUND: The effects of transfusion of HLA antibodies to patients with corresponding antigens are not well known. STUDY DESIGN AND METHODS: Records of patients who received blood from previous donations of a donor implicated in a case of transfusion-related acute lung injury (TRALI) were examined. The donor had multiple HLA antibodies reactive with 96 percent of HLA Class I antigens and 88 percent of HLA Class II antigens. RESULTS: Among 103 patients (40 with a pretransfusion white blood cell [WBC] count of >/=3.5 x 10(9)/L), 1 patient met criteria for TRALI and had clinical evidence for diffuse alveolar hemorrhage. Among the subset of 55 patients (17 with a pretransfusion WBC count of 3.5 x 10(9)/L) with known HLA types, none developed TRALI even though 54 (98%) had one to five corresponding HLA antigens. In a subgroup of patients four of 62 patients with chest radiographs, developed new or worse bilateral infiltrates with implicated but not control units (p = 0.0625). CONCLUSION: Transfusion of HLA antibodies from this donor to nonneutropenic patients did not cause TRALI, but there was a trend of an association with new or worse bilateral pulmonary infiltrates. Further research is needed to determine why transfusion of HLA antibodies to recipients with corresponding antigens causes TRALI in some cases and not in others.

Adult↗
PubMed2004

Acute and transient decrease in neutrophil count in transfusion-related acute lung injury: cases at one hospital.

BACKGROUND: Transfusion-related acute lung injury (TRALI) is a rare but serious complication of blood transfusion. The syndrome is characterized by new acute lung injury developing during or within 6 hours of blood transfusion. STUDY DESIGN AND METHODS: The study design was observational in nature. RESULTS: All three cases of TRALI were associated with acute but transient decrease in the white blood cell (WBC) count. Implicated donors had HLA antibodies that matched the recipients' HLA antigens. The implicated units were a plateletpheresis in one case and fresh frozen plasma units in the other two. All implicated donors were multiparous women. The implicated antibody specificities were anti-HLA Class I and Class II in one case and anti-HLA Class II in the other two cases. Interestingly, patient neutrophil counts decreased by 80 to 90 percent in all three cases, including the two cases associated with HLA Class II antibodies. CONCLUSION: An acute and transient decrease in WBC count may be a previously underrecognized feature of TRALI. A drop in the neutrophil count can occur even when the implicated antibodies have specificities to HLA Class II antigens, although they are expressed only on stimulated neutrophils. Based on the observations in these cases, it is recommended that a complete blood count and differential be obtained when TRALI is suspected. Further investigations into the mechanisms of the decrease in circulating neutrophils that is associated with infusion of HLA Class II antibody may yield new insights into the mechanism of TRALI.

Adult↗
PubMed2004

Transfusion-related acute lung injury.

Transfusion-related acute lung injury (TRALI) is the leading cause of transfusion-related mortality. It is characterized by injury to the alveolar-capillary membrane precipitated by transfusion factors, antibodies, and/or inflammatory mediators, in a susceptible host. In the absence of a specific test, TRALI is defined clinically as a syndrome of acute lung injury that develops during or within 6 h of transfusion. The absence of left atrial hypertension and large protein content of edema fluid may help differentiate TRALI from hydrostatic pulmonary edema. The treatment is supportive. The blood bank needs to be notified promptly so that an appropriate workup and prevention are initiated in a timely manner.

Acute Disease↗
PubMed2003

Heart rate increases linearly in response to acute isovolemic anemia.

BACKGROUND: The cardiovascular response to acute isovolemic anemia in humans is thought to differ from that of other species. Studies of anesthetized humans have found either no change or a decreased heart rate. A previous study showed that in 32 healthy unmedicated humans, heart rate increased during acute isovolemic anemia. The hypothesis that heart rate in humans increases in response to acute isovolemic anemia and that the increase is affected by gender was tested. STUDY DESIGN AND METHODS: Acute isovolemic anemia to a Hb concentration of approximately 5 g per dL in 95 unmedicated healthy humans was produced by simultaneous withdrawal of blood and IV replacement with 5-percent HSA and autologous platelet-rich plasma. The relationship between heart rate and Hb concentration was examined using a mixed-effects linear regression model that allowed each person to have a fitted line with its own slope and intercept. Cubic and quadratic terms were added to determine if these improved the goodness of fit. The effect of gender was tested by including it and its interactions with Hb in the mixed model. RESULTS: The relationship between heart rate and Hb concentration was linear (p < 0.001) and consistent among the population studied: heart rate = 116.0-4.0 [Hb] (slope 95% CI: -4.2 to -3.8 beats/min/g Hb). Adding a cubic or quadratic term did not significantly improve the goodness of fit of the mathematical expression to the data, confirming the linear nature of the relationship between heart rate and Hb concentration. For women, the slope of the heart rate response was significantly greater than it was for males (difference +/- SE: 0.70 +/- 0.23, p < 0.005). CONCLUSION: In 95 unmedicated, healthy humans, heart rate was a linear function of Hb during acute isovolemic anemia. Females had a significantly greater slope of increase in heart rate with decreasing Hb concentration than did males. The relationship is consistent among individuals, is similar to that reported for conscious dogs, and differs from that found previously in anesthetized humans.

Acute Disease↗
PubMed2003

Acute isovolemic anemia does not impair peripheral or central nerve conduction.

BACKGROUND: Previous studies have found subtle slowing of responses in tests of addition and digit-symbol substitution during acute severe isovolemic anemia to a hemoglobin concentration of 5 g/dl in healthy unmedicated humans. In this study, the authors tested the hypothesis that such changes relate to the slowing of afferent neural traffic. METHODS: The median nerve was stimulated at the wrist in seven healthy unmedicated volunteers before and after induction of acute isovolemic anemia to a nadir hemoglobin concentration of 5.1 +/- 0.3 g/dl (mean +/- SD). Times for neural impulses to travel from the stimulus site to the brachial plexus, cervical spinal cord, and cerebral cortex were measured using somatosensory evoked potentials. Tests were repeated during acute anemia with the subject breathing oxygen. As a control for time and intrasubject variation, the testing was repeated on a separate day when anemia was not produced at times equivalent to those on the experimental day. RESULTS: Induced acute severe isovolemic anemia decreased nerve conduction latencies from the wrist to the contralateral cerebral cortex (i.e., to the N20 peak) by 2.3 +/- 1.6% compared with values at a mean hemoglobin concentration of 12.7 g/dl (P < 0.01). These decreased latencies were due solely to an increased peripheral conduction velocity, from the wrist to the brachial plexus (P < 0.05), and were not altered when subjects breathed oxygen (P > 0.05). Conduction velocity from the brachial plexus or cervical spinal cord to the cerebral cortex did not change with acute anemia (P > 0.05). Latencies did not differ on the control day among the times of testing (all P > 0.05), nor did they differ at baseline between the control and experimental days (all P > 0.05). CONCLUSION: Somatosensory evoked potential latencies were not increased by acute severe isovolemic anemia, making it unlikely that the afferent portion of the neural system is responsible for slowing of cognitive responses previously observed during acute anemia. Because severe isovolemic anemia did not increase somatosensory evoked potential latencies, etiologies other than anemia should be sought if latencies are increased during intraoperative monitoring.

Acute Disease↗
PubMed2002

Oxygen reverses deficits of cognitive function and memory and increased heart rate induced by acute severe isovolemic anemia.

BACKGROUND: Erythrocytes are transfused to improve oxygen delivery and prevent or treat inadequate oxygenation of tissues. Acute isovolemic anemia subtly slows human data processing and degrades memory, increases heart rate, and decreases self-assessed energy level. Erythrocyte transfusion is efficacious in reversing these effects of acute anemia. We tested the hypothesis that increasing arterial oxygen pressure (Pao2) to 350 mmHg or greater would supply sufficient oxygen to be equivalent to augmenting hemoglobin concentration by 2-3 g/dl and thus reverse the effects of acute anemia. METHODS: Thirty-one healthy volunteers, aged 28 +/- 4 yr (mean +/- SD), were tested with verbal memory and standard, computerized neuropsychologic tests before and twice after acute isovolemic reduction of their hemoglobin concentration to 5.7 +/- 0.3 g/dl. Two sets of tests were performed in randomized order at the lower hemoglobin concentration: with the volunteer breathing room air or oxygen. The subject and those administering the tests and recording the results were unaware which gas was administered. As an additional control for duration of the experiment, 10 of these volunteers also completed the same tests on a separate day, without alteration of hemoglobin concentration, at times of the day similar to those on the experimental day. Heart rate, mean arterial blood pressure, and self-assessed sense of energy were recorded at the time of each test. RESULTS: Reaction time for digit-symbol substitution test increased, delayed memory was degraded, mean arterial pressure and energy level decreased, and heart rate increased at a hemoglobin concentration of 5.7 g/dl (all P < 0.05). Increasing Pao2 to 406 +/- 47 mmHg reversed the digit-symbol substitution test result and the delayed memory changes to values not different from those at the baseline hemoglobin concentration of 12.7 +/- 1.0 g/dl, and decreased heart rate (P < 0.05). However, mean arterial pressure and energy level changes were not altered with increased Pao2 during acute anemia. CONCLUSION: The authors confirmed that acute isovolemic anemia subtly slows human reaction time, degrades memory, increases heart rate, and decreases energy level. The findings of this study support the hypothesis that increasing Pao2 to 350 mmHg or greater by breathing oxygen reverses all of these effects of acute anemia except for decreased energy.

Acute Disease↗