Anatomical investigations on intraosseous access in stillborns - Comparison of different devices and techniques

Aim: Intraosseous (IO)-access plays an alternative route during resuscitation. Our study was performed to investigate the successful rate of IO-access in preterm and term stillborns using different devices and techniques. Methods: The cadavers used were legal donations. 16 stillborns, median: 29.2 weeks (IQR 27.2-38.4) were investigated. Two different needles (a: Butterfly needle, 21G, Venofix((R)) Fa.Braun; b: Arrow((R))EZ-IO((R))15G, Teleflex, Dublin, Ireland) were used. Needles were inserted i: manually, using a Butterfly needle; ii: manually, using EZ-O-(R) needle or iii: using a battery-powered semi-automatic drill (Arrow((R))EZ-IO (R)). Spectral-CT's were performed. The diameter of the corticalis was determined from the CT-images. Successful hit rates with 95% confidence intervals (Cl) and odds ratios between the three methods were estimated using a generalised linear mixed model (GLMM). Results: Estimated success rate was 61.1% (95%CI:39.7%-78.9%) for the Butterfly needle, 43.0% (95%CI:23.4%-65.0%) for hand-twisted EZ-IO (R) screwing and 39.7% (95%CI:24.1-57.7%) for the semi-automatic drill (Arrow((R))EZ-IO (R)), all referring to an average diameter of the corticalis of 1.2 mm. The odds of a correct position were 2.4 times higher (95%CI:0.8-7.6) when using the Butterfly needle than with the drill. In contrast, the odds of correct positioning when inserting the needle by hand were not significantly different from using the drill (odds ratio 1.1, 95%CI: 0.4-3.3). Neither of these effects nor the diameter of the corticalis with an odds ratio near one were significant in the model. Median diameter of the bone marrow cavity was 4.0 mm [IQR 3.3-4.7]. Conclusion: Intraosseous access for premature and neonatal infants could be best achieved by using a manually twisted Butterfly needle