IS airlock in blood infusion dangerous?

Yes, an airlock in a blood infusion can be extremely dangerous.

An airlock is a condition where air enters the bloodstream during a blood transfusion. Usually, an airlock happens when a blood bag containing blood is hung upside down because gravity allows air to enter the blood bag.

As that blood is infused, rather than receiving life-sustaining blood to treat anemia or other conditions, the patient begins to get air into the veins and blood vessels.

Small air emboli usually cause no symptoms and are reabsorbed by the body with no ill effect. However, a larger air embolus can cause a wide variety of symptoms, depending on its size, site of lodgement, and the amount of blood flow compromised, with the most serious symptom being respiratory distress. Treatment with 100% oxygen and fluids is recommended for large air emboli.