Monitoring of cyclosporine blood levels from central venous lines: a misleading assay?

In order to assess the suspected influence of indwelling lines on the measurement of cyclosporine (CSA) blood levels, we evaluated CSA concentrations in samples drawn simultaneously from both silicone catheter lumens and peripheral veins of eight bone marrow transplant recipients. Blood samples were obtained at 30 min or 6-12 h after discontinuation of intravenous CSA. CSA concentrations were determined in whole blood by specific monoclonal antibody assay. Mean CSA levels from the lumen used for CSA administration were significantly higher than those from samples drawn from the second lumen (i.e., not used for CSA infusion) or peripheral vein. This difference, obtained when the infusion had been interrupted for 30 min, was still the case 6-12 h after discontinuation of CSA infusion. No difference was found between samples obtained from the second lumen and peripheral vein. These observations suggest that CSA might be adsorbed or bound by the silicon catheter and, thus, CSA blood level measurements may be misleading. The second lumen of the catheter or a peripheral vein should be used for accurate monitoring of CSA concentrations.

[Use of central venous catheters implanted subcutaneously in children with neoplasms]. / Uso dei cateteri venosi centrali ad impianto sottocutaneo in bambini con malattia neoplastica.

The use of totally implantable right atrial catheters was evaluated in pediatric oncology patients. From September 15, 1987 to March 31, 1989, 26 catheters were inserted in patients (1 year to 20 years of age) with the following diagnosis: acute leukemia (6), osteosarcoma (5), lymphoma (4), central nervous system tumors (6), osteosarcoma (5), lymphoma (4), central nervous system tumors (6) and other solid tumors (5). Total number of catheter days was 5,475. The catheters were maintained for a mean of 210 days (range 10-534). Complications included: documented local infection in 1 patient, successfully treated with antibiotics without removing the catheter and transient obstructions resolved with injection of heparin or urokinase in other children. The use of these right atrial catheters has been widely accepted by patients and families as well as by the health team. Complications have been minimal. Our experience confirms that these catheters contribute to improving quality of life in pediatric patients with neoplasms.

[The external left jugular vein as an access for placement of long-term permanent central venous catheters in children]. / La vena giugulare esterna sinistra quale accesso per il posizionamento di cateteri venosi centrali adatti a lunga permanenza in pazienti pediatrici.

We consider the approach through the left external jugular vein v/s right external jugular vein (Heinbach-Ivey technique) for the placement of central venous catheters (Broviac Hickman type and others) in pediatric patients. Between January '84 and February '87, 65 central venous catheters were inserted using the Heinbach Ivey technique. In 24.6% of the cases we failed and had to place the catheter through the right internal jugular vein. Between March '87 and November '88, 72 catheters were inserted through the left external jugular vein, only 5 through the left internal jugular vein, with a failure rate of 6%. Our data show that a more favourable anatomy makes easier and quicker the correct placement of a central venous catheter through a left external jugular vein approach.