Overview of the use of implantable venous access devices in the management of children with inherited bleeding disorders

Summary.  Frequent infusion of factor concentrates may be challenging in young boys with haemophilia, especially if their disease is complicated by inhibitors. A central venous access device (CVAD) is often placed in young patients in need of repeated infusions for prophylaxis or immune tolerance induction. Although user friendly and capable of providing reliable venous access, these devices are associated with a high complication rate over time. In the haemophilia population, major complications include CVAD-associated infections and deep venous thrombosis, which is most often silent. Established risk factors for catheter-related infection include age less than 6 years at the time of CVAD placement and use of an external CVAD when compared with a totally implantable device such as a port. Avoidance of CVAD-related infections is facilitated by strict adherence to aseptic technique. The risk of deep venous thrombosis appears related to the duration for which the catheter is in place, with the risk increasing beyond 4 years. The promotion of a strict clinic policy in which CVADs are left in place for as short a time as possible should decrease the risk of complications. In rare cases where a totally implantable CVAD cannot be placed for technical reasons, an arteriovenous fistula may provide reliable venous access. In all cases, however, venous access via peripheral veins is preferred over CVADs.     

Aortic Stenosis

Noninvasive assessment of aortic valve area by echocardiography has become the standard of practice over the past few years. The advent of transesophageal echocardiography (TEE) has provided a new method for the assessment of aortic valve area (AVA) using planimetry by two-dimensional imaging. Clear visualization of the anatomy of the valve, as well as accuracy of AVA assessment, makes TEE an invaluable tool for the evaluation of aortic valve stenosis. TEE is especially helpful in clinical settings when there is a discrepancy between the AVA obtained by transthoracic echocardiography and cardiac catheterization. TEE is particularly helpful in the assessment of the aortic valve during intraoperative echocardiography. This review discusses the techniques, imaging planes, and details for assessing AVA by TEE. The role of TEE in AVA assessment is described, with specific clinical case examples cited.     

Neonatal Sepsis in Pakistan: Presentation and Pathogens

ABSTRACT. The case records of all neonates admitted to the neonatal unit at Aga Khan University Hospital (Karachi) in a 30 month period (Nov. 86April 89) were analysed. Of 60 neonates with confirmed sepsis, 33 (55%) had non-nosocomial infection (NNC) whereas 27 (45 %) had nosocomial sepsis (NC). The most common organisms causing early-onset NNC sepsis were Klebsiella species (53%) and Escherichia coli (10%), whereas the organisms causing late-onset NNC sepsis included Salmonella parathypi (21%), Group A Streptococcus (21%), Escherichia coli (14%) and Pseudomonas species (14%). Klebsiella was the most common organism causing NC sepsis, others being Staphylococcus aureus (15%) and Serratia species (15%). The mortality in NC sepsis, early-onset and late onset NNC sepsis was 44%, 26% and 43%, respectively. Risk factors associated with NNC sepsis included low birthweight, prematurity and prolonged and complicated deliveries. There was a high incidence of drug resistance to ampicillin and gentamicin among gram-negative organisms causing sepsis (mean 67 %).     

FAIL-SAFE DEVICE FOR AN OXYGEN FAILURE IN ANAESTHETIC APPARATUS

The criteria for an oxygen fail-safe device are designed toprevent a hypoxic gas mixture being administered to the patientshould the oxygen supply fail, be disconnected, or be turnedoff. A fail-safe device which fulfils these criteria is described.     

Comparative anti-fertility effects of gossypol enantiomers in male hamsters

The enantiomers of gossypol have been tested as male oral anti-fertility agents in hamsters. As determined by fertility tests the (-) isomer was fully active at half the effective dose of the racemate, whereas the (+) isomer exerted no anti-fertility effect.