Analysis of laboratory critical values at a referral Spanish tertiary university hospital.

INTRODUCTION: The aim of this study was to analyse critical value data from our laboratory and compare our critical value reporting policy with others in the literature. MATERIALS AND METHODS: Analysis of critical values was performed on data obtained over a 6-month period in a tertiary university hospital. RESULTS: We identified 5723 critical values, of which approximately 80% came from STAT testing (4577), 15% from routine inpatients testing (884) and 5% from routine outpatients testing (262). The highest proportion of critical values corresponded to oxygen partial pressure (17.7%), followed by potassium ion (17.6%) concentrations. The parameters associated with the highest critical value notification percentage in emergency patients were pH, haematocrit, glucose, potassium ion and haemoglobin concentrations. In inpatients, these parameters were glucose, phosphate, haemoglobin, sodium ion and potassium ion concentrations. In outpatients, they were calcium and potassium concentrations. CONCLUSIONS: The analysis of critical values in our hospital is in accordance with that reported in the literature. Our findings demonstrate the importance of incorporating improvement actions not only in critical value notification, but especially in the registration of this activity.

Measurement of ganciclovir concentration in human plasma by ultra-performance liquid chromatography-tandem mass spectrometry.

BACKGROUND: Ganciclovir/valganciclovir plays an important role in the treatment and prevention of cytomegalovirus disease after organ transplantation. MATERIAL AND METHODS: We developed and validated a simple chromatographic method by ultra-performance liquid chromatography tandem mass spectrometry to measure plasma concentration of ganciclovir in human plasma. Chromatographic separation was achieved using an Acquity(®) UPLC(®) BEH™ (2.1×50mm id, 1.7µm) reverse-phase C18 column, with a water/methanol linear gradient containing ammonium acetate/formic acid at a 0.4mL/min flow rate. Ganciclovir and its internal standard (acyclovir) were detected by electrospray ionization mass spectrometry in positive ion multiple reaction monitoring mode. RESULTS: The limit of detection and quantification were 0.03 and 0.06mg/L, respectively, and linearity was observed between 0.06 and 30.0mg/L. Intra-day and day-to-day coefficients of variation and relative biases ranged from 3.6 to 5.4%, 4.2 to 6.2%, -2.6 to -1.1% and -4.0 to -2.8%, respectively. Recovery values were greater than 81.9%. Evaluation of the matrix effect showed ion suppression for ganciclovir and acyclovir. No carry-over was observed. CONCLUSIONS: The validated method is useful for both therapeutic drug monitoring and pharmacokinetic studies. It could be applied to the daily clinical laboratory practice to measure the concentration of ganciclovir in human plasma.