Subcutaneous infusion ports in the pediatric patient with hemophilia.

Central venous access devices have become important tools in the management of pediatric patients with malnutrition, malignancy, and infections requiring long-term antibiotic treatment. Hemophilia presents a lifetime challenge for venous access and at times can be an urgent or life-threatening situation. Since 1986, the authors have implanted 11 subcutaneous infusion ports in nine patients with hemophilia. The systems have remained in place for up to 7 years, without major complications or problems. Two catheters were replaced, after 4 and 6 years, because of skin erosion and blockage, respectively. One catheter was removed after 7 years because of blockage following local trauma and was not replaced. A recent survey through the Canadian Hemophilia Centre Directors Group obtained a further 45 subcutaneous infusion ports in other centers across Canada. The benefits of this system are overwhelming enthusiasm by the parents and children and no major complications. Some of the patients are now HIV-positive and are able to use their system for ongoing drug therapy.

Computer assisted serum/biological fluid storage: hemophilia serum/plasma bank.

Samples are drawn from hemophiliacs to retrieve plasma and serum for testing and storage. The samples for testing are tested and the results compiled using a database computer program. The samples for storage are coded and stored at -70 degrees C under controlled conditions. The location of the samples is then entered into the database computer program. The results of the tests, or the stored sample location, can be easily retrieved using the computer.

Multiple pyarthrosis in human immunodeficiency virus-infected hemophiliacs.

Classically, a swollen, painful joint in a patient with hemophilia has been considered to be due to a hemarthrosis until otherwise proven, and treated immediately with appropriate coagulation factor replacement. Two cases of human immunodeficiency virus (hiv)-infected hemophiliacs presenting with an initial apparent hemarthrosis, complicated subsequently by numerous pyarthroses and sepsis are described. In light of the prevalence of hiv infection in the adult hemophiliac population with arthropathy, a reappraisal of the clinical caveat of immediate infusion without joint aspiration is required.

Bacterial-induced activation of erythrocyte T-antigen complicating necrotising enterocolitis: a case report.

Erythrocyte Thomsen-Friedenreich crypt antigen (T-antigen) activation is not an uncommon event in infants with severe necrotising enterocolitis (NEC). Transfusion of these infants with blood products containing plasma carries the risk of causing intravascular haemolysis. T-antigen activation is easily detected using a rapid simple lectin agglutination test. Early recognition of T-antigen activation ensures the correct choice of plasma free transfusion therapy. We describe an infant with severe NEC complicated by T-antigen activation and haemolysis.

Human recombinant DNA-derived antihemophilic factor (factor VIII) in the treatment of hemophilia A. recombinant Factor VIII Study Group.

BACKGROUND: Current treatment of hemophilia A, a hereditary disorder affecting approximately 1 in 10,000 males, relies on plasma-derived factor VIII concentrates. We tested the safety and efficacy of a recombinant factor VIII preparation for the treatment of this disorder. METHODS: We conducted the investigation in three stages: comparing the pharmacokinetics of plasma-derived and recombinant factor VIII, assessing the efficacy of recombinant factor VIII for home therapy, and assessing its efficacy for major surgical procedures and hemorrhage. A total of 107 subjects with hemophilia, 20 of whom had not been treated previously, enrolled in the investigation. RESULTS: The in vivo recovery and elimination half-lives of recombinant factor VIII equaled or exceeded those of plasma-derived factor VIII. Seventy-six subjects participated in a home-treatment program, using recombinant factor VIII for 69 to 807 days (median, 618); home diaries of 56 subjects treated for 5 months were analyzed. Of 540 bleeding episodes, 399 (73.9 percent) required only one treatment with recombinant factor VIII. The projected annual consumption of recombinant factor VIII was similar to that of plasma-derived factor VIII concentrate. Twenty-six subjects received recombinant factor VIII for 22 surgical procedures and 10 serious hemorrhages; hemostasis was excellent in all cases. De novo formation of inhibitors occurred in only 1 of 85 previously treated subjects. Inhibitor antibodies also developed in 6 of 21 children, 20 of whom had not previously been treated; 5 had low levels (less than or equal to 7.5 Bethesda units) despite continued treatment with recombinant factor VIII. There was no evidence of new formation of antibody to foreign proteins, and recombinant factor VIII was well tolerated. CONCLUSIONS: Recombinant factor VIII has biologic activity comparable to that of plasma factor VIII and is safe and efficacious for the treatment of hemophilia A.

Prescribing and dispensing practices for oral iron tablets: a Canadian experience.

The formulation of an oral iron tablet may influence its therapeutic efficacy in correcting iron deficiency. In order to determine the oral iron preparations patients in a Canadian urban center were receiving, a questionnaire was circulated to family physicians, internists, surgeons, and obstetrician-gynecologists to determine their prescribing practices. A survey of pharmacies in the city was also conducted to determine which brand of each iron salt (sulfate, gluconate, fumarate) they dispensed for a generic oral iron prescription. Most physicians (74 percent) chose ferrous sulfate as their drug of first choice. The majority of prescribers would not specifically request either enteric-coated/slow-release or nonenteric-coated preparations as first or second choices (71 and 64 percent, respectively). Enteric-coated or slow-release preparations were specified by 10 and 19 percent of physicians as first and second choices, respectively. Most pharmacies (96 percent) dispensed an enteric-coated preparation of ferrous sulfate for a generic prescription. We believe that many patients are receiving iron tablets with altered release properties (enteric-coated/slow-release). These tablets may fail to provide the desired therapeutic benefit based on the known physiology of iron absorption.

Sensitivity of the thrombin clotting time and activated partial thromboplastin time to low level of antithrombin III during heparin therapy.

The thrombin clotting time (TCT) has been used at our institution, along with the activated partial thromboplastin time (aPTT), for monitoring heparin therapy. We have observed that, in some patients, a discrepancy develops between the heparin levels predicted by the TCT and the aPTT with the TCT consistently predicting a lower heparin level than the aPTT. An inverse relationship was noted between the functional antithrombin III (AT-III) level and the magnitude of this discrepancy.

An audit of blood component therapy in a Canadian general teaching hospital.

As part of a quality assurance program a retrospective audit of transfusion practices for packed red blood cells, fresh frozen plasma and albumin was undertaken with predetermined criteria in a general teaching hospital. Of 520 transfusion episodes with 1218 units of packed red blood cells given to 297 patients 88% were considered appropriate; of 106 episodes with 405 units of fresh frozen plasma given to 83 patients 90% were deemed appropriate; and of 187 episodes with 320 units of albumin given to 99 patients 64% were considered appropriate. The results of this audit, when compared with those of other surveys of blood use in a similar population, suggest that pretransfusion approval of requested components would reduce the number of inappropriate transfusions.

An arteriovenous malformation in pregnancy: a case report and review of the literature.

A case is described of a young woman with progression of a macrofistulous arteriovenous malformation during pregnancy. This resulted in severe symptoms necessitating cesarean section, following which there was a dramatic postpartum recovery. The arteriovenous malformation was confirmed by angiography. The literature related to arteriovenous malformations in pregnancy is reviewed.

Intraventricular haemorrhage and haemostasis defects.

Twenty five of 106 preterm infants of 34 weeks' gestation or less developed intraventricular haemorrhage within the first 48 hours of life. A comparison of infants with and without intraventricular haemorrhage showed no significant differences in their haemostatic parameters at birth. At age 48 hours the group with intraventricular haemorrhage showed a prolonged activated partial thromboplastin time and reduced factor II, VII, and X activity. There was a significant correlation between the severity of intraventricular haemorrhage and the degree of haemostasis abnormality both in cord blood and in blood obtained at age 48 hours. Those infants sustaining grade IV intraventricular haemorrhage had a significantly prolonged activated partial thromboplastin time, reduced factor II, VII, and X activity; and a decreased fibrinogen concentration at birth. At age 48 hours these defects were accompanied by reduced platelet counts and an increased megathrombocyte index. Although intraventricular haemorrhage is multifactorial, we postulate that correction of haemostasis abnormalities at birth may prevent progression to more severe grades of haemorrhage.

'Normal' haemostasis parameters: a study in a well-defined inborn population of preterm infants.

Coagulation studies were performed in a well-defined inborn population of preterm neonates in cord blood and arterial blood obtained at age 48 h. Eighty infants fulfilled all the inclusion criteria. Our results show an increase in the hepatic vitamin K1 dependent and independent factors with postnatal age. The APTT became shorter, the factor II-VII-X, alpha 2-antiplasmin, plasminogen activities and fibrinogen level rose with increasing postnatal age. We found no change in the platelet parameters measured with postnatal age except that the megathrombocyte index was increased at age 48 h in infants less than 29 weeks gestation. There was little change with gestational age of any factors except the vitamin K1 dependent factors. Factor II-VII-X activity rose and the APTT became shorter with increasing gestational age. Many of the haemostasis results did not fall within the normal adult range. We discuss the significance of 'abnormal' and 'normal' results in preterm infants.

The use and safety of Ibuprofen in the hemophiliac.

After demonstrating initial safety of Ibuprofen administered to hemophiliacs, a 16-wk double-blind individual crossover trial was designed to test the safety and, to a more limited extent, the efficacy of 1600 mg of Ibuprofen or placebo given daily to 20 hemophiliacs with hemophiliac arthropathy. The trial was completed with no evidence of increased frequency or severity of hemophiliac bleeding episodes or clinical or laboratory evidence of bleeding secondary to Ibuprofen. There were five treatment failures, none associated with hemorrhage or lack of compliance. A benefit was obtained in reduction of early morning stiffness and pain. Ibuprofen should be considered as a safe and potentially beneficial antiinflammatory agent in the treatment of carefully monitored hemophiliacs eligible for such therapy.