Autotransfusion management during and after cardiopulmonary bypass alters fibrin degradation and transfusion requirements

The coagulation-fibrinolytic profile during cardiopulmonary bypass (CPB) has been widely documented. However, less information is available on the possible persistence of these alterations when autotransfusion is used in management of perioperative blood loss. This study was designed to explore the influence of autotransfusion management on intravascular fibrin degradation and postoperative transfusions. Thirty patients, undergoing elective primary isolated coronary bypass grafting, were randomly allocated either to a control group (group A; n=15) or an intervention group (group B; n=15) in which mediastinal and residual CPB blood was collected and processed by a continuous autotransfusion system before re-infusion. Intravascular fibrin degradation as indicated by D-dimer generation was measured at five specific intervals and corrected for hemodilution. In addition, chest tube drainage and need for homologous blood were monitored. D-dimer generation increased significantly during CPB in group A, from 312 to 633 vs. 291 to 356 ng/mL in group B (p = .001). The unprocessed residual blood (group A) revealed an unequivocal D-dimer elevation, 4131 +/- 1063 vs. 279 +/- 103 ng/mL for the processed residual in group B (p < .001). Consequently, in the first post-CPB period, the intravascular fibrin degradation was significantly elevated in group A compared with group B (p = .001). Twenty hours postoperatively, no significant difference in D-dimer levels was detected between both groups. However, a significant intra-group D-dimer elevation pre- vs. postoperative was noticed from 312 to 828 ng/mL in group A and from 291 to 588 ng/mL in group B (p < .01 for both). Postoperative chest tube drainage was higher in the patients from group A, which also had the highest postoperative D-dimer levels. Patients in group A perceived a higher need for transfusions of red cells suspensions postoperatively. These data clearly indicate that autotransfusion management during and after CPB suppresses early postoperative fibrin degradation.

KEYWORDS

cardiopulmonary bypass, cardiotomy suction, coronary surgery, autotransfusion, fibrin degradation.

Comparison of two highly discriminatory molecular fingerprinting assays for analysis of multiple Aspergillus fumigatus isolates from patients with invasive aspergillosis

Two highly discriminatory fingerprinting assays, short tandem repeat typing and amplified fragment length polymorphism (AFLP), were compared to determine the genetic relatedness between 55 isolates of Aspergillus fumigatus obtained from 15 different patients suffering from proven invasive aspergillosis. Both techniques showed that interpatient isolates belonged to different genotypes and that intrapatient isolates from deep sites were all of the same genotype. By contrast, multiple genotypes were found among isolates originating from respiratory samples. Both techniques have specific advantages and disadvantages. AFLP is more universally applicable, but short tandem repeat analysis offers better discriminatory power and should be the preferred method for standardizing typing of clinical isolates of Aspergillus fumigatus.

Imaging findings in acute invasive pulmonary aspergillosis: clinical significance of the halo sign

BACKGROUND

Computed tomography (CT) of the chest may be used to identify the halo sign, a macronodule surrounded by a perimeter of ground-glass opacity, which is an early sign of invasive pulmonary aspergillosis (IPA). This study analyzed chest CT findings at presentation from a large series of patients with IPA, to assess the prevalence of these imaging findings and to evaluate the clinical utility of the halo sign for early identification of this potentially life-threatening infection.

METHODS

Baseline chest CT imaging findings from 235 patients with IPA who participated in a previously published study were systematically analyzed. To evaluate the clinical utility of the halo sign for the early identification and treatment of IPA, we compared response to treatment and survival after 12 weeks of treatment in 143 patients who presented with a halo sign and in 79 patients with other imaging findings.

RESULTS

At presentation, most patients (94%) had > or =1 macronodules, and many (61%) also had halo signs. Other imaging findings at presentation, including consolidations (30%), infarct-shaped nodules (27%), cavitary lesions (20%), and air-crescent signs (10%), were less common. Patients presenting with a halo sign had significantly better responses to treatment (52% vs. 29%; P<.001) and greater survival to 84 days (71% vs. 53%; P<.01) than did patients who presented with other imaging findings.

CONCLUSIONS

Most patients presented with a halo sign and/or a macronodule in this large imaging study of IPA. Initiation of antifungal treatment on the basis of the identification of a halo sign by chest CT is associated with a significantly better response to treatment and improved survival.

Microbiologic consequences of new approaches to managing hematologic malignancies

Opportunistic infections have always been pitfalls on the road of progress in the treatment of diseases that are accompanied by compromised host defences. Because of the severe morbidity and mortality associated with these infections, they have become substantial challenges for the clinicians who offer such patients care. With medical progress, the number of immunocompromised patients is still steadily climbing and it has become evident that deficiencies in host defences mechanisms are multiple as well as changing in harmony with alterations in treatment modalities for underlying diseases. Under normal circumstances, the intact epithelial surfaces of the gastrointestinal tract will prohibit invasion by micro-organisms and the mucociliary barrier of the respiratory tract prevents aspiration of fungal cells and spores, while, in contrast, dead or damaged tissue creates a nidus for infection. It is, however, questionable whether transmigration of organisms inevitably leads to infection. With the growing use of potent immunosuppressive purine analogues, fludarabine, pentostatin and cladibrine, and anti-T and anti-B cell antibodies, such as rituximab and campath, in the management of lymphoreticular malignancies, in combination with increasing emphasis on dose intensity, the number of patients at risk has almost reached levels encountered in recipients of allogenic stem cell grafts as a consequence of long-lasting deficiencies in the cellular immunity. The spectrum of opportunistic pathogens are shifting as anti-leukemic and anti-lymphoma therapy become more intensive and bone marrow transplant practices evolve. Recent studies demonstrate, that patients treated with nonmyeloablative allogeneic transplantation (or "minitransplants") to reduce transplant-related toxicity, are at high risk of contracting a serious infections. Initially bacterial infections were most problematic. However, as strategies to control bacterial infections improved, viruses demanded more attention from the clinicians but the associated morbidity declined due to advances in rapid diagnostics and the introduction of effective antivirals such as acyclovir and ganciclovir. Next to viruses, resistant bacteria, particularly Gram-positive organisms like enterococci and methicillin-resistant staphylococci urged to vigilance. It was obvious that enhanced use of antibacterials inevitably will be accompanied by selection and induction of resistant organisms. Today, opportunistic fungi have become the most frequent and dangerous pathogens. Since the 1980's the rate of nosocomial invasive fungal diseases has doubled without any sign of slowing at the turn of the millenium. During the past decades we have even observed an increased incidence of invasive fungal infections in patients who are not in an end stage of their underlying disease. Yeasts and moulds rank amongst the most frequently isolated pathogens. The relative incidence of the various fungal infections depends on geography as well as on medical practices and local conditions. Candida Aspergillus species remain the prominent fungal pathogens but more rare species are increasingly cultured.

Should the Consensus Guidelines' Specific Criteria for the Diagnosis of Invasive Fungal Infection Be Changed?

The introduction of a standardized set of criteria to define invasive fungal infections has fulfilled a need. The criteria make comparisons between various clinical studies more easy and facilitate discussions of trial designs. However, application of the criteria in practice has indicated that some criteria for possible disease (in particular, antibiotic-resistant fever during neutropenia) are rather unspecific and allow the inclusion of patients who are unlikely to have an invasive fungal infection in trials. On the other hand, new diagnostic tools have been validated sufficiently to consolidate the effect of the criteria on the diagnosis of invasive fungal infections. Finally, it has become evident that changing medical practices with deleterious consequences for the innate immune system extend the population at risk for invasive fungal infections. This combination of factors has urged researchers to reconsider the continuing appropriateness of the current definitions.

Monitoring myeloablative therapy-induced small bowel toxicity by serum citrulline concentration: a comparison with sugar permeability tests

BACKGROUND

Intestinal mucositis is an important cause of cancer treatment-related morbidity and mortality, carrying a serious economic burden. Currently, objective parameters are lacking that would enable the monitoring of gut damage in routine clinical practice, thus hindering the development of clinical studies designed to investigate potential new strategies aimed at reducing or preventing this side effect. The authors investigated the characteristics of serum citrulline concentration compared with sugar permeability tests with respect to its use as a marker for cancer treatment-induced small bowel injury.

METHODS

In this prospective study, 10 patients with hematologic malignancies who were receiving myeloablative therapy had gut toxicity assessed with sugar permeability tests. Serum citrulline concentrations also were determined using archival serum samples. The association between both parameters and their respective characteristics were analyzed and compared with data from the literature.

RESULTS

Sensitivity and specificity were better for the citrulline assay compared with sugar permeability tests. Maximum gut damage assessed with the citrulline assay was observed 1-2 weeks earlier compared with the sugar permeability test. Similarly, citrulline indicated recovery of gut damage at 3 weeks after transplantation, whereas most sugar permeability tests remained abnormal.

CONCLUSIONS

The simplicity of the method, the low costs, and the lack of drawbacks to the method make the citrulline assay the first choice for measuring and monitoring treatment-related gut damage and provides an objective parameter for cancer treatment-related gut toxicity.