Venous access has been a problem for the practicing oncologist. Previous approaches, such as arteriovenous fistulas, grafts, or percutaneous catheters, have not gained widespread acceptability. We report our experiences with 230 Port-a-Cath devices, a totally implantable venous access system. The catheters were placed in 218 general oncology patients for the administration of chemotherapy. One patient had three catheters placed and 10 patients had two catheters each. Most patients received standard bolus chemotherapy, while 25 patients were treated with continuous ambulatory infusions. The catheters were in place for an average of 271 days (range 2–1,427 days) for a total of 62,330 catheter days, representing the largest published experience with devices of this type in cancer patients. A total of 24 complications occurred in 22 patients. Catheter insertion was associated with four pneumothoraces, two of which required chest tube drainage. Five catheters were removed because of infection. There were 6 cases of venous thrombosis, but none resulted in pulmonary embolism. Other complications were manageable and included catheter occlusion, migration, and extravasation of chemotherapy agents. The Port-a-Cath is safe and is associated with a low rate of complications. Implantable venous access systems represent a significant advantage in the management of oncology patients with poor venous access.

Tracheal mucous velocity (TMV) was measured in experimental canine asthma. All 10 sensitive dogs exposed to an aerosol of Ascaris suum extract showed a decrease in TMV to about one-third of base-line values within 45 min whereas only half of them (reactors) responded with bronchospasm as measured by a significant reduction in specific respiratory system conductance (SGrs). Mean TMV remained decreased at the end of the 2-h observation period when mean SGrs had returned to base-line values in the reactors. Neither TMV nor SGrs changed in nonsensitive animals who inhaled ragweed antigen. Aerosols of acetylcholine and histamine increased TMV thereby excluding these mediators as responsible for the impairment of mucous transport in asthma. Nebulization of A. suum antigen together with a selective antagonist of slow reacting substance of anaphylaxis (srs-a) produced a marked increase of TMV in all dogs regardless of whether or not bronchospasm was elicited. This suggests that the observed decrease in TMV may be related to the release of SRS-A during the immunologic reaction.

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Drug stability and compatibility studies should be performed for all medications added to total nutrient admixtures (TNAs) before administration to patients. The stability of TNA components will vary depending on product selection and final concentrations. This variability prohibits generalizing published study results generically to TNAs containing untested products or combinations. Histamine receptor antagonists (H2RAs) are commonly administered by continuous infusion via nutrient solutions. When the delivery vehicle is a TNA, comparative stability and compatibility studies performed under similar test conditions are lacking. The stability of marketed parenteral H2RAs and of the investigational H2RA, nizatidine was analyzed in TNA solutions containing either Liposyn II or Intralipid at differing concentrations. All H2RAs remained at more than 90% of initial concentration at 24 hours. After 48 hours, only ranitidine concentrations fell to less than 90% in all study solutions. Each TNA containing an H2RA was within pH stability ranges for lipid products, and no change in particle size was detected during the 48-hour period. This is the first report determining H2RA compatibility and stability in TNA solutions with both 3% and 5% Intralipid and Liposyn II and using similar methodology for all standard H2RA concentrations. Results suggest that these drugs are stable for 24 hours in TNAs containing either lipid product. Beyond this time, administration of ranitidine may be unreliable because of poor stability under the conditions tested.