One-chamber and two-chamber parenteral nutrition admixtures for pediatric and adult patients: An evaluation of physico-chemical stability at room and cold temperature.

OBJECTIVES: The aim of this study was to evaluate the physico-chemical stability of compounded total parenteral nutrition admixtures through peroxidation assay and ultraviolet-visible spectroscopy, high-performance liquid chromatography analysis, nuclear magnetic resonance spectrometry, pH meter, and dynamic light scattering. METHODS: The present study considered parenteral nutrition (PN) admixtures for pediatric and adult patients. The admixtures were characterized by a high content of vitamins and trace elements. They were prepared in one- or two-chamber bags in the hospital pharmacy using an automatic compounding system in a sterile room with laminar airflow at different temperature conditions and light exposure. The experiment setup comprised fat emulsions, lipid-free PN solutions, and single-chamber bags before and after adding vitamins and trace elements. The stability at room temperature (+25°C) and cold temperature (+2-8°C) was assessed by various means. RESULTS: Two-compartment admixtures, single-chamber bags, and all-in-one PN supplemented with vitamins and trace elements are stable up until 35, 9, and 7 d, respectively, when protected from light and stored at +2 to 8°C. Also, the supplemented single-chamber PN was found to be stable up to 48 h when stored at +25°C with light exposure. CONCLUSIONS: The results obtained will help improve PN management at the compounding center and in hospital wards, because they allow for the extension of the validity time frame provided so far by the different formulations and, therefore, therapy scheduling over several days.

Rejection of hemolyzed samples can jeopardize patient safety.

INTRODUCTION: In vitro hemolysis is the primary cause of sample/test rejection by the laboratory. CASE REPORT: A 10-year-old, admitted with an asthma attack in the emergency-room, medicated with albuterol sulphate (intravenous bronchodilator that could induce hypokalemia), needed laboratory test monitoring. The physician prescribed the technical-nurse to perform blood sampling for: complete blood count, electrolytes, glucose, and blood gas analysis-within 30min after therapy. Samples were delivered to laboratory with a note "I had difficult to locate an appropriate access to perform the blood collection". LABORATORY RESULTS: Glucose: 4.77 mmol/L. Complete blood count revealed discreet eosinophilia 0.13x109/L, and thrombocytopenia 18x109/L. However, platelet clumps were observed in peripheral blood smear. Blood gas analysis was unreported, laboratory informed that sample had micro clots.Electrolytes: laboratory did not report the results; sample hemolyzed. 0.9 g/L of free hemoglobin is the cut-off defined by the laboratory; the sample presented 2.3 g/L of free hemoglobin. 3.9 mmol/L of potassium was the unreported result vs 2.1 mmol/L in the new sample.Briefly, the laboratory technician was trained to hide potassium results on hemolyzed sample due to the potential overestimation. Even if the hemolyzed sample presented a potassium value close to the lower reference range value (3.5-5.1 mmol/L), reporting the potassium result could allow the physician starting proper therapy to revert the hypokalemia by albuterol sulfate. CONCLUSION: The laboratory should be aware of the clinical patient conditions and of the related physician needs, before hiding results. Therefore, both the laboratory and the clinic personnel should communicate in order to guarantee the patient safety.