Patients for whom precautions should be considered:
(1) small circulating blood volume (where 500 mL is likely to represent a significant percent of the total blood volume)
(1a) an elderly patient who is very thin
(1b) an anorexic patient
(1c) a pediatric patient
(2) moderate to severe cardiopulmonary disease
(2a) cor pulmonale in hypoxic lung disease
(2b) cardiomyopathy in hemochromatosis
(2c) Eisenmenger syndrome
(3) orthostatic hypotension
(4) history of syncope after blood donation or routine phlebotomy
(5) excessive anxiety
Precautions to consider:
(1) Performing the phlebotomy in an area accessible to emergency response.
(2) Performing the phlebotomy with the patient in a monitored bed, especially if there is severe cardiopulmonary disease.
(3) If the patient is unlikely to tolerate a drop in blood volume, perform a euvolemic phlebotomy with simultaneous infusion of crystalloid or colloid solution.
(4) Removing a smaller volume than the standard single unit (500 mL), typically 250 mL or less.
(5) Allow the patient to remain recumbent for a longer period after phlebotomy and prevent sudden change in position.
(6) Make sure the room temperature is not too warm (may predispose to syncope).
