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3PC-046 Parenteral nutrition admixtures: review of the microbiological sampling plan
  1. C Sampaio1,
  2. A Capela1,
  3. R Barbosa1,
  4. S Fraga1,
  5. T Soares1,
  6. M Ribeiro2,
  7. C Teixeira2
  1. 1Centro Hospitalar Universitário São João, Pharmacy, 4200–319 Porto, Portugal
  2. 2Centro Hospitalar Universitário São João, Clinical Pathology, 4200–319 Porto, Portugal


Background and importance Sterility testing of parenteral nutrition (PN) is described in pharmacopoeias and establishes the minimum number of units that must be tested. Normally, no quality control testing is performed for extemporaneously prepared products. In our procedure, to evaluate the efficacy of the working method, samples are taken from personalised and stock PN mixtures as part of the control process.

Aim and objectives To evaluate the number of PN samples taken for microbiological control and its compliance with pharmacopoeial specifications. To test the possibility of reducing the number of PN samples taken and the economic impact associated with this.

Material and methods This was a retrospective study of the microbiological control of PN bags from October 2018 to September 2019. Data were obtained from pharmacy and microbiology laboratory records. The parameters measured were: PN bags produced, PN samples taken versus recommended by pharmacopoeial specifications and economic impact. Costs were calculated considering the value attributed to the sterility test.

Results During the studied period, 12 466 PN bags were prepared and 1723 were tested. Four of the control bags had a positive result (0.23%). In no case was the result compatible with infection or isolation of the same microorganism in blood culture. Analysis of the data by day of the week showed an average number of bags assessed for control/prepared of 7/49 (Monday), 4/26 (Tuesday), 7/42 (Wednesday), 7/51 (Thursday) and 9/76 (Friday). According to the pharmacopoeial specifications, for production less than 100 units, the minimum number of units to be tested should be 10% or 4 units, whichever is greater. Therefore, applying these average values to the production, the minimum number of samples taken should be: 5 (Monday), 4 (Tuesday), 4 (Wednesday), 5 (Thursday) and 8 (Friday). The predictable decrease in the number analysed would imply a cost saving of €9575/year.

Conclusion and relevance The procedure in operation consists of random sampling of 1 in 5 prepared PN bags. These results, as well as a history of low and stable positive controls, will allow an increase in the sampling interval to 1 in 10. The cost saving achieved will allow other studies to be performed with the microbiology team, improving the management of material and human resources.

References and/or acknowledgements No conflict of interest.

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