Alpha-adrenergic receptor blockers , which work by blocking adrenergic nerve receptors in the lower urinary tract , basically help relax the smooth muscle of the prostate and bladder neck to relieve pressure and to improve urine flow .
Finally , disconnecting the patient from the entilator could result in a marked increase in work of breathing and in adrenergic state and hence in increased cardiac work and myocardial oxygen demand with the potential risk of myocardial ischemia in patients with prior coronary artery disease .