What is the key blood test to perform after severe hypotension from a hymenoptera sting?

The key blood test to perform after severe hypotension from a hymenoptera sting is tryptase. Measuring serum tryptase levels is crucial in cases of anaphylaxis, such as that potentially caused by bee or wasp stings. Tryptase is an enzyme released by mast cells during anaphylactic reactions, and elevated levels can indicate the severity of the reaction and help confirm a diagnosis of anaphylaxis.

This timing is important; tryptase levels peak within one to two hours after the reaction and can remain elevated for several hours. This makes it a vital marker in evaluating patients who have experienced severe hypotension or other anaphylactic manifestations following a sting. In contrast, while total IgE may provide information about a patient's overall allergic predisposition and serum electrolytes and complete blood count can offer insights into other conditions, they do not specifically help in confirming anaphylaxis or in assessing the acute response to a hymenoptera sting.