P Ancic1, F Muñoz. 1. Departamento de Medicina, Facultad de Medicina, Universidad de Chile.
Abstract
BACKGROUND: Several frequent errors in the measurement of arterial blood gases, shed doubts on their real usefulness. AIM: To identify sampling, manipulation and transport errors in the measurement of arterial blood gases. MATERIALS AND METHODS: Three hundred and nine consecutive arterial blood samples received at the central laboratory of a public hospital were analyzed. Patient data in the order form, reception conditions at the laboratory, transport media, time of arrival and analysis of each sample were recorded. RESULTS: Five percent of orders informed the hour of sampling, 0.6% the patient's temperature and 18.1% the inspired oxygen fraction. Bubbles or clots were present in 12.9% and 3.2% of samples respectively, 87.3% of samples were well sealed and the amount of blood withdrawn in relation to the syringe capacity was optimal in 47.2% of cases. Ninety three percent of syringes were transported with ice cubes that did no cover the syringe and 5.8% of samples were received at room temperature. The delay in analysis, since the time of reception at the laboratory, ranged from 0 to 55 min (mean 12.9 min). CONCLUSIONS: Several deficiencies in pre analytical variables in blood gas analysis were identified, most caused by neglect and susceptible of correction. Quality controls for this determination should be performed frequently.
BACKGROUND: Several frequent errors in the measurement of arterial blood gases, shed doubts on their real usefulness. AIM: To identify sampling, manipulation and transport errors in the measurement of arterial blood gases. MATERIALS AND METHODS: Three hundred and nine consecutive arterial blood samples received at the central laboratory of a public hospital were analyzed. Patient data in the order form, reception conditions at the laboratory, transport media, time of arrival and analysis of each sample were recorded. RESULTS: Five percent of orders informed the hour of sampling, 0.6% the patient's temperature and 18.1% the inspired oxygen fraction. Bubbles or clots were present in 12.9% and 3.2% of samples respectively, 87.3% of samples were well sealed and the amount of blood withdrawn in relation to the syringe capacity was optimal in 47.2% of cases. Ninety three percent of syringes were transported with ice cubes that did no cover the syringe and 5.8% of samples were received at room temperature. The delay in analysis, since the time of reception at the laboratory, ranged from 0 to 55 min (mean 12.9 min). CONCLUSIONS: Several deficiencies in pre analytical variables in blood gas analysis were identified, most caused by neglect and susceptible of correction. Quality controls for this determination should be performed frequently.