Intraosseous samples can be used for opioid measurements – An experimental study in the anaesthetized pig

Abstract

Aim. The intraosseous route provides access to the systemic circulation in an emergency situation when other forms of vascular access are unavailable and there is an urgent need for fluid or drug therapy. The intraosseous access has also been used for collecting samples for laboratory testing. A question that may arise in an unconscious or severely exhausted patient is whether this condition is caused by an unknown drug. We aimed to evaluate whether intraosseous samples could be used to measure opioids and to study the accuracy and precision of such measurements. Methods. Five healthy, anaesthetized pigs were treated with a continuous morphine infusion as part of the anaesthesia procedure. Samples for morphine testing were collected hourly for 6 h from two tibial intraosseous cannulae and a central venous catheter. Results. The differences in morphine concentrations between the two tibial intraosseous cannulae were less than 10% in 32/33 times. The values were also relatively stable over time. Conclusion. Our findings suggest that intraosseous samples can be used for the analysis of opioids if an IV route is not available.