First, notice that bubbles are stopped by the drip chamber on the IV, or if there's an infusion pump instead of a drip chamber, the pump itself will detect it and stop the flow.
If there is a small bubble or two in the line after the drip chamber or pump, notice that it doesn't go anywhere. It just sits there and doesn't move with the fluid so it never ...
The distribution of valves in the veins can vary greatly.
Relationship of Common Vascular Anatomy to Cannulated Catheters (Hindawi, 2017):
Veins of the antecubital fossa [anterior side of the elbow] were much less
likely to have valves, whereas veins of the hand and forearm were
nearly equal in the frequency of valves identified. In ...
A vein that has undergone venipuncture woud be more dificult to extract blood because it is already traumatized/injured. Some veins would be thicker when healed and some would be friable. That's why they alternate arms for phlebotomy to allow your veins to heal.
Experience wise, there's nothing much we can do about it. But i find it easier to extract blood ...
In venous lacerations, blood would be able to be stopped by placing a tourniquet below the injury. By stopping the blood from returning from the limb, you wouod be able to effectively prevent blood loss. This would work in the rare case of just the vein being cut, but it's safer to place the tourniquet above the injury in case the vein is not the only thing ...
Larger needles aren't used to draw blood faster in general. They are used to avoid hemolysis. 16-18 gauge needles:
A large needle (16 to 17 gauge) is used to minimize shearing
forces that may physically damage red blood cells as they flow through
What maybe used to speed up the process is:
Sqeezing your fists
Tourniquets or blood ...