Search

Background and Objectives: Immune‐mediated acute or delayed transfusion reactions occur when there is immunological incompatibility between transfused blood products and recipient's antibodies. Acute haemolytic transfusion reactions occur within 24 h and are delayed after 24 h up to 10 days following transfusion, whereas post‐transfusion purpura (PTP) typically occurs 7–10 days post‐transfusion. We present a case of a previously transfused and recently post‐partum female who developed both delayed haemolytic transfusion reaction (DHTR) and PTP. Case Report: A 42‐year‐old woman, G2P1, with non‐alcoholic liver disease, portal hypertension and previous transfusion history with allogeneic anti‐E, developed a severe DHTR and PTP following a complicated post‐partum course and multiple transfusions. The antenatal and initial post‐partum pre‐transfusion antibody screens were negative. Subsequently five red cell antibodies, including anti‐c, anti‐Fya, anti‐Jkb and anti‐S and the reappearance of anti‐E were, however, identified during follow‐up investigations along with the anti‐platelet antibody HPA‐3a and human leukocyte antigen class I antibodies. Anti‐E, anti‐Jkb and anti‐S were eluted from the circulating red blood cells. Conclusion: To our knowledge, there have been only two other case reports of DHTR and PTP occurring in the same patient. [ABSTRACT FROM AUTHOR]

Background and Objectives: Although it remains controversial, premedication before transfusion is a common clinical practice to prevent transfusion‐associated adverse reactions (TAARs) in Taiwan. Thus, we aimed to investigate whether premedication prevented outpatients from developing TAARs and whether an educational programme could improve the understanding of physicians related to the unnecessary use of premedication, and this could elicit changes in their prescribing activities without affecting the occurrence of TAARs. Materials and Methods: Clinical data from outpatients receiving transfusion therapy, including predisposing diseases, histories of transfusion and TAARs, premedication and the occurrence of TAARs in the period April 2017 to October 2018, were retrospectively obtained. The evidence‐based transfusion programme implemented to educate physicians was started in January 2018. Results: A total of 5018 blood units were transfused to 803 outpatients, with 2493 transfusion events reported in the study interval. The most frequently transfused component was leukocyte‐reduced packed red cells (n = 4338), followed by leukocyte‐reduced apheresis platelets (n = 540) and other blood components. The overall premedication rate significantly decreased from 92.4% to 76.7% after the educational programme (p < 0.001). There was no remarkable change in the occurrence of TAARs per patient event between the periods before and after the educational programme (1.11% vs. 1.14%, p = 0.964). Besides, it was shown that the occurrence of TAARs was associated with the history of TAARs and inversely related to multiple transfusions, but not premedication. Conclusion: Decreased premedication was not associated with increased incidence of TAARs in outpatients; these findings provide important evidence to support the need to revise clinical practices in the era of leukocyte‐reduced blood products. [ABSTRACT FROM AUTHOR]

Objective: Hemovigilance covers the entire transfusion chain, from the collection of the blood product and its components to the monitoring of adverse reactions. The aim of our study was to perform a process validation for the hemovigilance system of our hospital and to evaluate patients who developed blood transfusion reactions. Method: University of Health Sciences Turkey, Dr. Behçet Uz Child Health and Diseases Training and Research Hospital; among the patients who received blood transfusion between January 2019 and December 2019, 238 patients were identified by systematic sampling method. Blood components used in patients undergoing treatment in different clinics; Examining the physician and nurse observation notes and the data in the hospital information system, whether the transfusion process is appropriate; It was evaluated by hospital hemovigilance coordinator, hemovigilance nurse, pediatric hematologist and pediatric intensive care specialist. Results: Of the 238 randomly selected patients, 122 (51.3%) were male and 116 (48.7%) were determined as female. The median age was 91 (14-180) months. In the evaluation of the transfusion process; Only 1 patient (0.4%) was observed to exceed the optimal transfusion time. No error was detected in other blood transfusion processes. It was observed that 8 (3.3%) of the patients who underwent transfusion had a transfusion reaction. Conclusion: In our study, it was found that there is no significant problem in recognizing, applying and reporting transfusion reactions before and during transfusion applications. In our country, there is no previous study on hemovigilance process validation. Prospective process validations are required. [ABSTRACT FROM AUTHOR]

Objectives: Washing cellular blood products is accepted to ameliorate repeated severe allergic reactions but is associated with RBC hemolysis and suboptimal platelet function. We compared in vitro hemolysis and platelet function in blood components after washing with Plasma-Lyte A (PL-A) vs normal saline (NS).Methods: RBC (n = 14) were washed/resuspended in NS or PL-A. Free hemoglobin and heme were determined at 0, 24, 48, and 72 hours. Platelet concentrates (PCs; n = 21) were washed with NS or PL-A and resuspended in same washing solution (n = 13) or ABO-identical plasma (n = 8). Platelet aggregation and spreading were evaluated.Results: The 24-hour free hemoglobin and heme levels were higher in NS (P < .05). Improved platelet function was observed in PL-A-washed PCs (P < .001).Discussion: PL-A showed less RBC hemolysis and better platelet function than NS. Whether such differences would occur in vivo is unknown. [ABSTRACT FROM AUTHOR]

Background: Red blood cell (RBC) transfusion is associated with the most transfusion‐related adverse events (AE). Recent clinical studies showed no significant difference in transfusion‐associated mortality between fresh and older RBCs. However, the impact of storage duration as well as irradiation on nonfatal yet much more common complications has not been fully investigated. Materials/methods: In this retrospective study of RBC transfusion‐associated AEs, a total of 188,562 units of leucocyte‐reduced RBCs were transfused in approximately 5·5 years. After excluding washed, deglycerolized, autologous or directed RBCs and RBCs transfused during a massive transfusion protocol, 149,052 units were analysed. Attributes of RBCs including storage time, collection method, CMV serological status and gamma irradiation, as well as the recipient's gender, were analysed. A total of 358 RBC transfusion AEs were categorized into allergic and non‐allergic reactions and analysed. Results: Univariate and multivariate logistic analyses showed that irradiated RBCs were associated with a significantly increased frequency of non‐allergic reactions (OR (95% CI): 1·89 (1·52, 2·35); P < 0·001). There was a significant association between the frequency of non‐allergic reactions and the storage time of irradiated RBCs (OR (95% CI): 1·024 (1·001, 1·048); P = 0·042). In contrast, there was no association between the frequency of allergic reactions and the storage time of irradiated RBCs or between the age of non‐irradiated RBCs and the frequency of non‐allergic reactions. Conclusions: Prolonged storage of irradiated RBCs was associated with a significant increase in non‐allergic transfusion reactions. Overall, the irradiated RBCs appeared to cause more non‐allergic reactions compared with non‐irradiated RBCs. [ABSTRACT FROM AUTHOR]

Background: Platelets (PLTs) have been associated with the highest rate of transfusion‐associated adverse events (AEs) among all blood products. Most of PLT‐associated AEs are considered to have an inflammatory mechanism. However, it is still unclear whether prolonged storage of platelets is associated with an increased rate of transfusion‐related AEs, especially in the era of universal prestorage leucoreduction. Methods/Materials: In this retrospective study, 52 649 PLT products consisting of about 80% apheresis PLTs and 20% whole blood‐derived (WBD) PLTs were transfused to 9415 patients from July 2011 to March 2017. All the PLTs were leucoreduced prior to storage. All but 69 units of the apheresis PLTs were irradiated and none of WBD PLTs were irradiated. During this period, a total of 284 AEs that were reported to the transfusion service were analysed. Results: Univariate and multivariate logistic analyses showed that apheresis/irradiated PLTs and PLT age were associated with a significantly increased frequency of inflammation type AEs (OR (95% CI): 2·24 (1·32, 4·15) and 1·30 (1·12, 1·52), respectively). There was a significant increase in the frequency of inflammation AEs associated with prolonged storage of apheresis/irradiated PLTs [OR (95% CI): 1·26 (1·03, 1·53)]. In contrast, there was no association between allergic symptoms and PLT age. Moreover, the frequency of transfusion AEs associated with apheresis/irradiated PLTs (57·2/10 000) was significantly higher than that of WBD/nonirradiated PLTs (26·0/10 000) (P < 0·01). Conclusion: Prolonged storage of apheresis/irradiated PLTs was associated with a higher frequency of inflammation AEs. Apheresis/irradiated PLTs caused more AEs than WBD/nonirradiated PLTs. [ABSTRACT FROM AUTHOR]

Mitochondria are organelles in charge of energy supply and the control of apoptosis. Owing to their similarities with bacteria, however, extracellular mitochondria are considered damage-associated molecular patterns ( DAMPs) capable of activating the immune system and non-immune cells. Studies revealed that diverse blood products contain extracellular mitochondria, which could account for the adverse reactions that can occur in transfusion. In this review, we discuss how mitochondrial DAMPs can trigger inflammatory responses, we highlight conditions relevant to transfusion during which mitochondria have been identified outside cells, and we discuss their potential as biomarkers for the assessment of blood product quality. [ABSTRACT FROM AUTHOR]

Appropriate management of non-infectious adverse transfusion reactions begins with recognition that a change in clinical status during or following a transfusion may represent an adverse event. Appropriate monitoring of patients during transfusion and explicit training of staff to recognize the signs and symptoms of adverse transfusion reactions is the key to diagnosis and to management. As some reactions may occur in the hours following transfusion, patient education and instruction on reporting relevant symptoms are also important. The typical symptoms that herald the onset of a transfusion-related adverse event include fever, rash, shock and respiratory distress. Haemoglobinuria may also be a presenting feature. Early signs or symptoms may reflect more than one type of reaction. All transfusionists must be aware of the steps in acute management of a suspected adverse transfusion reaction. For those events that occur while the transfusion is ongoing, stopping the infusion and maintaining the intravenous access are the important first step. Rapid evaluation of the patient's vital signs, a bedside check of the unit and patient identification, as well as assessment of the appearance of the blood component, are early steps. Supportive care based on the patient's signs and symptoms must occur while additional laboratory and clinical investigations are initiated. In most cases of transfusion-related adverse events, a 'posttransfusion' blood sample should be evaluated for the possibility of serological incompatibility. In addition, most moderate and severe reactions would be investigated with a blood count, renal and liver function tests and assessment of urine for haemoglobin. Other specific investigations depend on the presenting features and initial serologic findings. Based on the clinical, laboratory and/or imaging studies, most transfusion-related adverse events can be classified into one of the categories of acute transfusion reactions. These include acute haemolytic transfusion reactions, febrile non-haemolytic, allergic, anaphylactoid, septic, circulatory overload, hypotension and transfusion-related acute lung injury. Transfusion-associated graft-versus-host disease and posttransfusion purpura can be considered in some circumstances and delayed haemolytic transfusion reactions may be seen in the days to week following a transfusion. This diagnostic classification is important in optimizing acute management and may also contribute to decisions about component selection for subsequent transfusion. Reporting of adverse transfusion events is also an important part of management. Reporting to the hospital blood bank assists with diagnosis and decisions regarding future blood component therapy. The hospital transfusion committee may monitor transfusion reaction rates and trends as a quality indicator that can be used to change practices. The blood supplier must be notified of all reactions which may be attributable to a particular donor or donor unit, especially if recall or quarantine of associated blood components may be necessary. Regional or national haemovigilance programmes may require notification and can contribute to changes in standard practices to address common or serious adverse transfusion events and in early recognition of uncommon complications. [ABSTRACT FROM AUTHOR]

Background Fever is described in transfusion-associated circulatory overload ( TACO), reflecting either comprehensive haemovigilance or an inflammatory pathobiology (such as congestion-associated atheroma disruptions). Methods Hospital haemovigilance data (1/1/2010-31/12/2012) were reviewed for TACO cases (frequency and mode of referral). TACO with or without fever ( TACO+F/−F) was examined for its association with patient age (as a surrogate for atheroma burden) and product age (as a surrogate for storage-related pyrogens). Fever in allergic transfusion reactions was also compared. Results Of 972 reactions, 107 suspected cases of TACO (11%) were seen. TACO+F vs. TACO−F occurred in 42·1 vs. 57·9%, respectively. TACO+F cases were discovered in referrals to investigate either a fever (in 47·1%) or dyspnoea (in 52·9%). Among TACO+F cases, 24·4% had already been febrile, whereas 75·6% exhibited a new reaction-associated fever. After excluding preexisting fevers, TACO+F occurred in 31·8% of TACO, compared with 8·2% of allergic reactions with fever, for an odds ratio of 5·2 (2·9-9·4 [95% CI]), P < 0·001. TACO+F/ TACO−F showed no difference in median host age (69 vs. 64 years, P = 0·3), RBC age (22 days +F/−F, P = 0·9) or severity. Conclusion Transfusion-associated circulatory overload disproportionately exhibits fever compared with allergic reactions. However, TACO+F did not associate with patient or product age, nor reflect severity. To better understand TACO+F, the fever-congestion sequence merits attention. Further study is needed to see whether TACO+F occurs as reproducibly elsewhere, and in association with atherosclerosis in a better characterized cohort. [ABSTRACT FROM AUTHOR]

Background and objectives Platelet concentrates ( PCs) are associated with transfusion reactions involving hypotension, particularly bradykinin-mediated acute hypotensive transfusion reactions. This study aims to determine the incidence of hypotensive events and more specifically acute hypotensive transfusion reaction associated with PC transfusions. We also sought to ascertain whether these reactions are associated with elevated bradykinin levels. Materials and Methods This is a prospective descriptive study of PCs administered at Sainte-Justine Hospital over 28 months. All PCs administered during this period were screened for hypotension through review of all transfusion-associated reaction reports ( TARRs) sent to the blood bank. All residual PC bags were returned to the blood bank. TARRs associated with hypotension were reviewed by adjudicators that established the imputability of the PC transfusion to the reaction. Bradykinin levels were sampled in the first 168 PC bags returned to the blood bank. Levels were compared between PCs associated with hypotension and control PCs not associated with hypotension. Results A total of 3672 PC bags were returned to the blood bank; 25 PCs were associated with hypotension. Adjudicators ascertained that five hypotensive events were imputable to PCs of which one was an acute hypotensive transfusion reaction (incidence: 0·03%). Bradykinin level in the latter PC was 10 pg/ml, whereas levels were 226·2 ± 1252 pg/ml in the 143 control PCs. Conclusion Our results show a low incidence of hypotension after PC transfusion. We identified only one acute hypotensive transfusion reaction. No correlation between bradykinin level and the occurrence of acute hypotensive reactions could be observed given that only one event was identified. [ABSTRACT FROM AUTHOR]

Background and Aim Blood transfusion is a frequent and integral part of critical patient care. Even though life-saving, it could be occasionally risky and result in a spectrum of adverse events. Haemovigilance programme is a standard set-up to monitor the entire transfusion chain, evaluate and analyse the data to improve patient's safety. The haemovigilance programme has been established in India very recently. We report the implemented haemovigilance programme at a tertiary care hospital in the north-east of India. Methods and Materials This study was prospective and observational. It was carried out for a period of 9 months, from September 2013 to May 2014, in the State of the Art Model Blood Bank, Gauhati Medical College and Hospital, Guwahati, Assam, India. Transfusion reaction reporting forms, which are supplied by the Indian Pharmacopoeia Commission, were utilized to collect the data. Results A total of 51 000 blood components were transfused and 106 adverse events reported during the period of the study. The major stakes of adverse events were febrile non-haemolytic transfusion reactions (50%), pruritus (17·92%) and rigour/chills (11·32%). All the adverse events were found to be Grade 1 (non-severe) type, and there were no severe or life-threatening adverse events. [ABSTRACT FROM AUTHOR]

Background and Objectives One of the challenges surrounding blood component administration is the determination of an appropriate rate of infusion. There are very few evidence-based guidelines available to guide healthcare providers looking for a 'standard' infusion rate for red blood cells ( RBCs), plasma or platelets ( PLTs). Our objective was to determine the extent to which blood component infusion rates were associated with changes in transfusion recipient vital signs. Materials and Methods We retrospectively examined records of 3496 component infusions ( RBCs, n = 2359; PLTs, n = 478; plasma, n = 659) over a 1-year period at a 362-bed multispecialty hospital. The following data were collected for each transfusion: blood product volume and infusion time, recipient pre- and post-transfusion temperature, blood pressure and pulse rate, and hospital ward where transfusion occurred. Results Plasma (median 10·4 ml/min) was infused faster than PLTs (median 7·2 ml/min, P < 0·0001) or RBCs (median 2·3 ml/min, P < 0·0001). For all blood components, infusion rates varied based on the hospital unit performing the infusion. No association was found between relatively fast RBC, plasma or PLT infusion rates (>20 ml/min) and clinically significant reported changes in vital signs. Conclusions There does not appear to be a strong correlation between infusion rate and significant changes in recipient temperature, blood pressure or pulse rate. Based on these data, a reasonable rate for routine transfusion is 2-3 ml/min for RBCs and 7-10 ml/min for plasma and PLTs. Faster infusion rates (>20 ml/min) likely can be applied with close patient monitoring if there is a more urgent need for transfusion. [ABSTRACT FROM AUTHOR]

Background: In general, patients with significant anti-Ig-A do not tolerate intravenous (i.v.) administration of normal blood products. Here, we present our experiences in the induction of immune tolerance (IIT) and long-term treatment in a series of such patients affected in such a way. The question whether blood components from IgA-deficient donors are required will be discussed. Methods: Ten adult patients (4 females and 6 males; age ranging from 36 to 75 years) with anti-IgA were included in this study. All patients required long-term treatment with blood components. One patient had IgA deficiency and paroxysmal nocturnal hemoglobinuria (PNH), and all other patients had common variable immunodeficiency (CVID). The particle gel immunoassay was used for the detection of anti-IgA. Immune tolerance to IgA was induced by controlled subcutaneous (s.c.) and/or i.v. infusions of IgG preparations. Results: Prior to IIT, anti-IgA was detectable in plasma samples of all patients and significantly diminished or abolished by controlled s.c. and/or i.v. infusions of IgG. Multiple transfusions with normal blood components could be repeatedly performed with the patient suffering from PNH without any complications. As long as i.v. IgG (IVIgG) infusions were consequently administered as individually required (intervals 2-8 weeks), none of the patients developed reactions during observation (up to 10 years). However, interruption of treatment and re-exposure to IVIgG resulted in adverse reactions. Conclusion: Patients with significant anti-IgA can be safely desensitized and tolerate long-term IgG substitutions independent of the IgA concentration of the used blood component. [ABSTRACT FROM AUTHOR]

Platelet transfusions play a central role in therapeutic regimens for patients with hematologic/oncologic diseases who develop severe thrombocytopenia either in the course of their disease or following cytostatic therapy. Like other blood components, platelet transfusions have achieved a high degree of safety as far as transmission of viral diseases is concerned. However, transfusion of platelet concentrates is accompanied by a high frequency of febrile and anaphylactoid reactions. In rare cases, recipients of platelet concentrates are threatened by severe reactions as septic complications due to bacterial contamination of platelet concentrates, transfusionrelated acute lung injury and severe anaphylactic episodes. Copyright © 2008 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Unlabelled: Haemovigilance is defined as the collection of information on complications of transfusion, the analysis of the data, and suggestions for improvement in the transfusion service. A national haemovigilance system is of value in identifying possible areas in need of improvement in the national transfusion system. Haemovigilance becomes even more important if the system is used to compare the situation in one country with the situation in other countries, e.g. if the countries differ significantly in products used. The current study focuses on immunological transfusion complications, especially TRALI, as published in haemovigilance reports from Denmark, Norway, Sweden and the UK. Results: In Norway immunological transfusion reactions occurred 96.7 times per 100 000 red cell (RBC) transfusion, 231.1 times per 100 000 thrombocyte (Trc) concentrate transfusion and five times per 100.000 transfusions of solvent detergent treated plasma (SD plasma). Denmark and the UK have similar rates of transfusion reactions to RBC and fresh frozen plasma (FFP), but quite different for Trc (0.5 vs. 4.9 per 100 000). In 49% of reported TRALI the causative product is FFP, but no case of TRALI after SD plasma transfusion has been reported. Discussion: When considering all reports for immunological complications in Norway, the most striking is the very small number of reports related to SD plasma. Comparing data from Denmark and the UK shows a big difference in reactions caused by thrombocyte concentrates that may reflect different production methods in the two countries. TRALI is most often caused by FFP, but has never been reported after SD plasma transfusion. Heamovigilance data can be valuable in choosing the safest products available. [ABSTRACT FROM AUTHOR]

In 2000, the American Red Cross (ARC) received reports of unusual transfusion reactions of unknown aetiology among patients receiving leucocyte-reduced (LR) red blood cell (RBC) units in multiple distribution regions. We evaluated potential risk factors of reactions among patients who received LR-RBC transfusions. A case–patient was defined as any patient with onset of back pain while receiving an LR-RBC transfusion from 1 January to 25 May 2000. Controls were chosen randomly and selected in a 1:3 case : control ratio from healthcare facilities in which case–patients were transfused. Product-specific risk factors of reactions were further determined through nested case–control study, procedural review of blood collection facility and quality-control-testing record review of product processing. Reaction incidence rates were determined through ARC blood product distribution data by region of blood collection and processing. There were 29 reactions detected in patients who received transfusions in 13 healthcare facilities in five states. Eighteen case–patients and 78 controls were included in the case–control study. In univariate analysis, case–patients were more likely than controls to have a haematologic malignancy, to have received the transfusion as an outpatient, to have received an RBC transfusion within the previous 3 months, to have received medication used to prevent reactions or to diminish their intensity upon transfusion (i.e. premedication) or to have received LR-RBC units prepared with the HemaSure r\LS System™ (HS) rather than two other filters used. In multivariate analysis limited to recipients of HS-filtered RBC units, transfusion premedication [adjusted odds ratio (AOR) = 7; 95% confidence interval (CI) 1·4–37; P = 0·02] and transfusion as an outpatient (AOR = 5; 95% CI 1·1–20; P = 0·03) were independently associated with reactions. The rate of reported transfusion reactions was 2·0 reactions per 10 000 RBC units distributed. A multistate cluster of transfusion reactions was significantly associated with leucocyte filtration of RBC units prepared with a specific product, the HS filter. The reactions also were independently associated with premedication and transfusion as an outpatient; these may be surrogates for an increased risk of reaction or for greater likelihood of detection. The mechanism for these reactions has not been elucidated. This cluster of reactions underscores the importance of surveillance efforts to detect adverse events after transfusion, particularly when new methods to modify blood products are introduced. [ABSTRACT FROM AUTHOR]

Background. Universal leukodepletion of blood components to prevent acute non-hemolytic transfusion reactions (NHTRs) is still a subject of debate.Patients and methods. Transfusion-associated NHTRs observed at our hospital in the last 6 years were retrospectively analyzed. Buffy-coat depleted red blood cells (bc-RBCs), and if indicated, leucodepleted post-storage (ld-RBCs) were initially used. In April 1997, universal leukodepletion was implemented at our hospital, and thereafter only prestorage ld-RBCs were used. All platelet concentrates transfused during this time were prestorage filtered single-donor apheresis platelets (SDAPs).Results. A total of 163,090 blood products were transfused from April 1995 to April 2001 (bc-RBC: n=34,040 units; ld-RBC: n=66,967; SDAP: n=14,516; FFP: n=47,567). The number of post-transfusion febrile NHTRs occurring with each blood product was 65 (0.19%) for bc-RBCs, 8 (0.16%) for post-storage ld-RBCs, 16 (0.03%) for prestorage ld-RBCs, 16 (0.11%) for SDAPs, and 10 (0.02%) for FFP. Allergic reactions (n=116) were most frequently observed after SDAP transfusion (0.32%) and occurred at a similarly low rate after transfusion of all other blood components (0.03–0.08%).Conclusion. In conclusion, acute NHTRs rarely occur after the use of leukodepleted blood components. Prestorage appears to be more effective than post-storage leukodepletion in preventing febrile reactions following a blood transfusion. [Copyright &y& Elsevier]

We summarise recent advances in transfusion medicine applicable to cardiac surgery and cardiac transplantation. It is important that clinicians know the risks of blood transfusion in Australia. They should also be aware of the different types of transfusion reaction so that there is early recognition and investigation. Blood conservation strategies including acceptance of normovolaemic anaemia in clinically stable patients are important in reducing the requirement for red cell transfusion. Cytomegalovirus (CMV) seronegative blood products are recommended for heart transplant recipients with no evidence of prior CMV infection. Leucodepletion of units of unknown CMV status reduces the risk of CMV infection and are an acceptable alternative when seronegative units are unavailable. Leucodepletion of cellular blood products has been shown to reduce infection rates postoperatively in a large trial involving cardiac surgical patients. Further studies are needed to confirm this promising finding. Irradiation of blood products eliminates the risk of transfusion-associated graft versus host disease. Routine preoperative screening for cold agglutinins is no longer recommended. (Heart, Lung and Circulation 2002; 11: 42-51). [ABSTRACT FROM AUTHOR]