Transfusion-transmissible infections and transfusion-related immunomodulation

Trends in transfusion of trauma victims--evaluation of changes in clinical practice

Background

The present study was performed to compare blood product consumption and clinical results in consecutive, unselected trauma patients during the first 6 months of year 2002, 2004 and 2007.

Methods

Clinical data, blood product consumption, lowest haemoglobin values on day 1-10 after admission, and 30-day mortality were extracted from in-hospital trauma registry and the blood bank data base. The subpopulation of massively transfused patients was identified and analysed separately.

Results

The total number of admitted trauma patients increased by 48% from 2002 to 2007, but the clinical data remained essentially unchanged. The mean number of erythrocyte units given day 1-10 decreased insignificantly from 9.4 in 2002 to 6.8 in 2007. New Injury Severity Score (NISS) increased in transfused and massively transfused patients, but not significantly. The number of patients transfused with plasma increased and the mean ratio of erythrocyte to plasma units transfused decreased by about 50%. The mean haemoglobin value in transfused patients on day 2 after admittance was significantly lower in 2007 than in 2002, while that on day 10 was significantly higher in 2007 than in 2002 and 2004. There was no change of 30-day survival from 2002 to 2007.

Conclusions

Significant changes of transfusion practice occurred during the past decade, probably as a result of increased focus on haemostasis and more precise criteria for transfusion. Despite a lower consumption of erythrocytes in 2007 than in 2002 and 2004, the mean haemoglobin level of transfused patients was higher on day 10 in 2007. The low number of transfused patients in this material makes evaluation of effect on survival difficult. Larger studies with strict control of all influencing factors are needed.

Differential effects of plasma and red blood cell transfusions on acute lung injury and infection risk following liver transplantation

Patients with chronic liver disease have an increased risk of developing transfusion-related acute lung injury (TRALI) from plasma-containing blood products. Similarly, red blood cell transfusions have been associated with postoperative and nosocomial infections in surgical and critical care populations. Patients undergoing liver transplantation receive large amounts of cellular and plasma-containing blood components, but it is presently unclear which blood components are associated with these postoperative complications. A retrospective cohort study of 525 consecutive liver transplant patients revealed a perioperative TRALI rate of 1.3% (7/525, 95% confidence interval = 0.6%-2.7%), which was associated with increases in the hospital mortality rate [28.6% (2/7) versus 2.9% (15/518), P = 0.02] and the intensive care unit length of stay [2 (1-11 days) versus 0 days (0-2 days), P = 0.03]. Only high-plasma-containing blood products (plasma and platelets) were associated with the development of TRALI. Seventy-four of 525 patients (14.1%) developed a postoperative infection, and this was also associated with increased in-hospital mortality [10.8% (8/74) versus 2.0% (9/451), P < 0.01] and a prolonged length of stay. Multivariate logistic regression determined that the number of transfused red blood cell units (adjusted odds ratio = 1.08, 95% confidence interval = 1.02-1.14, P < 0.01), the presence of perioperative renal dysfunction, and reoperation were significantly associated with postoperative infection. In conclusion, patients undergoing liver transplantation have a high risk of developing postoperative complications from blood transfusion. Plasma-containing blood products were associated with the development of TRALI, whereas red blood cells were associated with the development of postoperative infections in a dose-dependent manner.

Intraoperative thromboelastometry is associated with reduced transfusion prevalence in pediatric cardiac surgery

BACKGROUND

The majority of pediatric cardiac surgery patients receive blood transfusions. We hypothesized that the routine use of intraoperative thromboelastometry to guide transfusion decisions would reduce the overall proportion of patients receiving transfusions in pediatric cardiac surgery.

METHODS

One hundred pediatric cardiac surgery patients were included in the study. Fifty patients (study group) were prospectively included and compared with 50 procedure- and age-matched control patients (control group). In the study group, thromboelastometry, performed during cardiopulmonary bypass, guided intraoperative transfusions. Intraoperative and postoperative transfusions of packed red blood cells, fresh frozen plasma, platelets, and fibrinogen concentrates, and postoperative blood loss and hemoglobin levels were compared between the 2 groups.

RESULTS

The proportion of patients receiving any intraoperative or postoperative transfusion of packed red blood cells, fresh frozen plasma, platelets, or fibrinogen concentrates was significantly lower in the study group than in the control group (32 of 50 [64%] vs 46 of 50 [92%], respectively; P < 0.001). Significantly fewer patients in the study group received transfusions of packed red blood cells (58% vs 78%, P = 0.032) and plasma (14% vs 78%, P < 0.001), whereas more patients in the study group received transfusions of platelets (38% vs 12%, P = 0.002) and fibrinogen concentrates (16% vs 2%, P = 0.015). Neither postoperative blood loss nor postoperative hemoglobin levels differed significantly between the study group and the control group.

CONCLUSIONS

The results suggest that routine use of intraoperative thromboelastometry in pediatric cardiac surgery to guide transfusions is associated with a reduced proportion of patients receiving transfusions and an altered transfusion pattern.

Blood transfusions and the subsequent risk of hematologic malignancies

BACKGROUND

Blood transfusions are associated with viral transmission and immunomodulation, perhaps increasing subsequent risk of hematologic malignancies (HMs). Prior studies of transfusion recipients have lacked details on specific HM subtypes.

STUDY DESIGN AND METHODS

Risk of HM after blood transfusion was evaluated in a US population-based case-control study (77,488 elderly HM cases identified through cancer registries, 154,509 controls). Transfusions were identified using linked Medicare hospitalization claims. Polytomous logistic regression was used to calculate odds ratios (ORs) associating transfusion and HM subtypes by features suggestive of a causal relationship.

RESULTS

A history of transfusion was present in 7.9% of HM cases versus 5.9% of controls. Associations for most HM subtypes suggested reverse causality: ORs were elevated only during the shortest latency periods; ORs for unspecified anemia and gastrointestinal bleeding, which may be related to undiagnosed HM, were stronger than for surgeries, which are unlikely to be related to HM; and/or there was no dose response. In contrast, risk for lymphoplasmacytic lymphoma (1397 cases) was elevated at long latency (OR, 1.56 at 10+ years after transfusion), after transfusions related to surgeries (OR, 1.22-1.47), and in a dose-response relationship with number of transfusion-related hospitalizations (OR, 1.53 with one hospitalization; OR, 1.80 with two or more hospitalizations, p trend < 0.0001). Risk for marginal zone lymphoma (1915 cases) was also elevated at 10+ years after transfusion (OR, 1.80).

CONCLUSION

Consistent with prior studies, blood transfusions did not increase risk of most HM subtypes. Patterns of elevated risk for lymphoplasmacytic and marginal zone lymphomas suggest an etiologic role for transfusion.

The optimal hematocrit

Nearly 15 million units of packed red blood cells and whole blood are transfused annually in the United States alone. Until recently, the major risks from blood transfusion were thought to be transmission of viral infections, and overall, blood transfusion was believed by most providers to be safe. A safe hemoglobin threshold above which red cell transfusion is clearly unnecessary has not been established. This article addresses the numerous problems that surround the use and consequences of blood transfusion, such as hemoglobin and hematocrit levels, oxygenation, storage time, immunomodulation, infection, and anemia. The relevant literature is comprehensively reviewed.

Complications of massive transfusion

Massive transfusion (MT) is a lifesaving treatment of hemorrhagic shock, but can be associated with significant complications. The lethal triad of acidosis, hypothermia, and coagulopathy associated with MT is associated with a high mortality rate. Other complications include hypothermia, acid/base derangements, electrolyte abnormalities (hypocalcemia, hypomagnesemia, hypokalemia, hyperkalemia), citrate toxicity, and transfusion-associated acute lung injury. Blood transfusion in trauma, surgery, and critical care has been identified as an independent predictor of multiple organ failure, systemic inflammatory response syndrome, increased infection, and increased mortality in multiple studies. Once definitive control of hemorrhage has been established, a restrictive approach to blood transfusion should be implemented to minimize further complications.

Transfusion in trauma: why and how should we change our current practice?

PURPOSE OF REVIEW

Major trauma is often associated with hemorrhage and transfusion of blood and blood products, which are all associated with adverse clinical outcome. The aim of this review is to emphasize why bleeding and coagulation has to be monitored closely in trauma patients and to discuss the rationale behind modern and future transfusion strategies.

RECENT FINDINGS

Hemorrhage is a major cause of early death after trauma. Apart from the initial injuries, hemorrhage is significantly promoted by coagulopathy. Early identification of the underlying cause of hemorrhage with coagulation tests (routine and bedside) in conjunction with blood gas analysis allow early goal-directed treatment of coagulation disorders and anemia, thereby stopping bleeding and reducing transfusion requirements. These treatment options have to be adapted to the civilian and noncivilian sector. Transfusion of blood and its components is critical in the management of trauma hemorrhage, but is per se associated with adverse outcome. Decisions must weigh the potential benefits and harms.

SUMMARY

Future transfusion strategies are based on early and continuous assessment of the bleeding and coagulation status of trauma patients. This allows specific and goal-directed treatment, thereby optimizing the patient's coagulation status early, minimizing the patient's exposure to blood products, reducing costs and improving the patient's outcome.

Anaesthetic considerations of the HIV-infected patients

PURPOSE OF REVIEW

Human immunodeficiency virus (HIV) infection is one of the major global health problems. Because the advances in treatment of HIV infection increase the patient's survival, anaesthesiologists may care for these patients during their practice. This article highlights HIV infection and anaesthetic implications.

RECENT FINDINGS

HIV infection is a spectrum of disease varying from asymptomatic to multiple organ involvement. Safe anaesthetic management in HIV-infected patients includes understanding basic knowledge of HIV infection, organ involvement, pharmacology and adverse reactions of antiretroviral agents. There are no specific anaesthetic agents and techniques for HIV-infected patients. Issues on central neural blockade and immunological aspects on HIV infection were discussed. Infection control to prevent transmission of infections to and from HIV-infected patients must be strictly conducted.

SUMMARY

Anaesthesia in HIV-infected patients should be individualized and depend on the status of the patient.