Confirmation of intraosseous cannula placement based on pressure measured at the cannula during squeezing the extremity in a piglet model

We sought to assess the reliability of the method using the pressure measured at the intraosseous (IO) cannula while squeezing the involved limb (P(squeezing)) in determining the position of the IO needle and to compare its performance with that of the traditional confirmation method.Eighty limbs of twenty domestic swine were assigned to one of three conditions regarding the position of the IO needle; correct placement (n=40), incorrect placement in which the IO needle was placed into the subcutaneous space without entering the bone (incorrect-subcutaneous placement, n=20), or incorrect placement in which the IO needle passed entirely through the bone (incorrect-penetrating placement, n=20). A blinded investigator randomly identified the position of the needle by the traditional method or test method using P(squeezing). If P(squeezing) was 80 mmHg or higher, the IO cannula was regarded as incorrectly placed.P(squeezing) was higher in incorrect placements (176.0 mmHg (130.0-195.0)) compared with that in correct placements (27.0 mmHg (20.0-34.0)) (p0.001). The test method correctly identified all 40 placements, but the traditional method was incorrect for one (5%) of 20 correct placements (p=1.000) and 7 (35%) of 20 incorrect placements (p=0.008). In incorrect placements, false positive results occurred mainly in incorrect-penetrating placements.We suggest that the method using the pressure measured at the IO cannula can be used when there is uncertainty about the position of the IO cannula after determination using traditional methods.