When should the removal of the sheath coincide with the patient's actions?

The correct choice is exhalation, as this aligns with the principles of minimizing vascular complications and discomfort during sheath removal. When the patient exhales, there is typically a decrease in intrathoracic pressure, which can help reduce the chances of air entering the vascular system and can also assist in venous return. This technique is often employed to ensure that vascular access sites can effectively seal off once the sheath is removed, thereby mitigating bleeding risks and ensuring that the patient remains stable throughout the procedure.

Inhalation would increase intrathoracic pressure and could potentially complicate the process. Coughing can induce abrupt changes in pressure and might lead to increased cardiovascular strain, which is not ideal at the moment of sheath removal. Removing the sheath while the patient is sleeping does not play a role in utilizing the patient's breathing patterns to optimize the safety of the procedure, as the patient would be unresponsive and may not synchronize their breathing appropriately with the removal.