Abstract 49: Comparison of Intraosseous Proximal Humerus and Sternal Routes for Drug Delivery during CPR
Intravenous access can be delayed during medical emergencies such as shock and cardiac arrest. The intraosseous (IO) route delivers drugs into the non-collapsible vessels within the bone marrow and can be an effective alternative to intravenous (IV) access. Recently, there have been a number of intraosseous devices developed for the adult market. A previous study from our group has shown the sternal IO to be 90% as effective as central IV in drug delivered during CPR and delivers drugs 2.5 times as fast as the tibial IO route. However, the safety of sternal puncture continues to be debated. Drug delivery via the proximal humerus may be an effective alternative for IV drug delivery during CPR.
METHODS: Seven isoflurane anesthetized swine (30 – 45kg) were subjected to cardiac arrest by KCl injection. Eight min post cardiac arrest CPR was initiated via Thumper (Michigan Instruments Inc.) at 100 compressions per min without ventilation. Delivery of epinephrine was evaluated by 2 routes after 2 min of CPR. Group 1 EZ-IO® (Vidacare Corporation, San Antonio, TX) was placed in the proximal humerus (PH), Group 2 EZ-IO placed in the sternum (S). After 2 min of CPR post VF Evans blue 5mg/kg and indocyanine green 2.5mg/kg tracers were co-administered with epinephrine (.2mg/kg) as a bolus to the S and PH, respectively. Post drug delivery arterial sampling was performed at 10s intervals for 8 min and analyzed by spectrophotometric assay to determine the arterial dose and time of drug delivery. Plasma was collected for HPLC analysis to determine arterial dose and time of delivery.
RESULTS: Peak appearance times of tracers were S 32.5 s ± 4.1 and PH 35 s ± 4.6, respectively. The total dose delivered to arterial blood averaged over 8 min was same for both the S and PH routes.
CONCLUSIONS: This study suggests that IO proximal humerus is comparable to IO sternal for prompt drug delivery during CPR. Previous work from our laboratory determined that IO sternum was 90% as effective in the dose delivered as central venous drug delivery. IO delivery via the proximal humerus is an effective and efficacious alternative to IO sternal delivery.