Precipitate Analysis from an Indwelling Total Parenteral Nutrition Catheter

Abstract

The composition of a precipitate obtained from a silastic right atrial catheter was determined. The precipitate was collected and washed with deionized water thoroughly before subjecting portions of it to organic and inorganic analysis. Inorganic analysis was conducted using scanning electron microscopy and x-ray spectroscopy for sodium, aluminum, silicone, sulfur, chlorine, and calcium. Phosphorus analysis was conducted by a commercial laboratory. Organic analysis was conducted by thin layer chromatography with cholesterol, phosphatidyl serine, phosphatidyl choline, phosphatidyl ethanolamine, and sphingomyelin as standards. Silicone, calcium, and phosphorus and three organic compounds, which could not be conclusively identified, were found. The precipitate was most likely calcium phosphate intermixed with silicone oil lubricant and residual total parenteral nutrition (TPN) solution. This formed in the catheter at body temperature probably due to incomplete catheter flushing.

Issues Concerning the Safety of Calcium Chloride in Neonatal Parenteral Nutrition

“…In the 5 of 6 cases that were fatal, no filter was used. We also found reports of 10 cases of catheter occlusion associated with Ca and P precipitation 12 – 15 . In all the above cases, the Ca and P concentrations were in the precipitation zone on curves established using visual methods.…”

Inappropriate Medication Administration Practices in Canadian Adult ICUs: A Multicenter, Cross-Sectional Observational Study

“…and local and systemic inflammatory reactions. [21][22][23] Catheter occlusion is the most common complication of CVC use, occurring in up to 25% of all CVCs used, and can interrupt the infusion of vital nutrition or medication. 24 The composition of the occluding material most often includes crystalline precipitate of drug incorporated into densely cross-linked fibrin matrices and entrapped blood cells.…”

Access technique and its problems in parenteral nutrition – Guidelines on Parenteral Nutrition, Chapter 9

“…Calcium phosphate precipitates are of special significance, and are influenced by various factors in the admixture like amino acid composition, relative calcium and phosphate content, pH etc. [180], [181]. A subcutaneously implanted permanent catheter, which is occluded due to insoluble precipitates, can be potentially re-utilised by pH changes in the PN solution [182], [183], [184], [185].…”