My goal is no bubbles and this is why. This is talking about what happens when air enters a vein during intravenous treatment.

"Air bubbles of less than 30 milliliters are thought to dissolve into the circulation harmlessly. Small volumes do not result in readily detectable symptoms, but ongoing studies hypothesize that these "micro-bubbles" may have some adverse effects. A larger amount of air, if delivered all at once, can cause life-threatening damage to pulmonary circulation, or, if extremely large (3-8 milliliters per kilogram of body weight), can stop the heart.

One reason veins are preferred over arteries for intravascular administration is because the flow will pass through the lungs before passing through the body. Air bubbles can leave the blood through the lungs. A patient with a heart defect causing a right-to-left shunt is vulnerable to embolism from smaller amounts of air. Fatality by air embolism is vanishingly rare, in part because it is also difficult to diagnose."