Calcium phosphate crystal occlusion of central venous catheters used for total parenteral nutrition in infants and children: prevention and treatment.

Calcium phosphate crystal occlusion is a complication occasionally encountered with long-term indwelling Silastic central venous catheters used for total parenteral nutrition (TPN) in infants and children. These occluded catheters are usually treated by removal. We have successfully treated six patients who experienced seven episodes of calcium phosphate crystal central venous catheter occlusion by irrigating their catheters with a hydrochloric (HCl) acid heparin solution. Although temporary febrile reactions occurred in three cases (42%), no serious complications were encountered. An average of 46 catheter-days per patient episode were preserved. By paying close attention to the calcium and phosphate concentrations in a patient's TPN solution, the clinician can minimize the risk of calcium phosphate precipitation. If central venous catheter occlusion does occur due to precipitation of calcium phosphate crystals, then HCl-heparin irrigation is a safe and effective method for salvaging such catheters.