A 4-year-old child presents in cardiopulmonary arrest after being found at the bottom of a swimming pool. CPR is administered by paramedics, and an intraosseous needle and endotracheal tube are inserted.
What confirms that an intraosseous needle is correctly inserted into the marrow cavity?
1 An X-ray showing the needle is in the bone
2 A sudden increase in resistance as the needle passes through the bony cortex and reaches the other side
3 Pulsations of blood can be seen in the hub
4 The needle remains upright without support
5 Insertion of the needle up to the hub