Shy-Drager Disease

More common in men than in women.

Symptoms begin in fifth-seventh decades of life.

Autonomic dysfunction with CV collapse due to decreased sympathetic outflow and abnormal parasympathetic homeostatic mechanisms

Aspiration risk

Orthostatic hypotension and intraop fluctuations in BP, particularly during induction.

Response to sympathomimetic drugs is unpredictable and may be exaggerated owing to denervation hypersensitivity.

Little or no HR or BP response to indirect sympathomimetic agents (i.e., ephedrine, methamphetamine) or anticholinergic medications (i.e., atropine).

Hyperresponsiveness of BP to hyperventilation/hypoventilation (hypercapnia/hypocapnia).

Loss of baroreceptive response leads to hyperresponsiveness to volume status and sudden changes in blood volume.

Cannot use sweating, tachycardia, or BP as indicators of anesthesia depth.

Positive-pressure ventilation can decrease venous return and cause dramatic hypotension without associated change in HR.

Up to 50% of pts will have supine hypertension.

Liver blood flow can be dependent on posture, so hepatically cleared drugs’ plasma levels can be highly dependent on posture.

Lyte abnormalities: Hypokalemia and hypomagnesemia when treated with fludrocortisone.

Central sleep apnea: Apneic syndromes due to impaired central regulation of respiration.

Obstructive sleep apnea: Found in advanced stages.

Vocal cord paralysis due to laryngeal muscle dysfunction: Found in advanced stages.

Impaired GI motility increased the risk of aspiration as well as postop ileus.

Faulty thermoregulatory systems: Hyperthermia-induced hypotension, lack of peripheral vasoconstriction to cold environment, can lead to hypothermia and hypotension.

Irreversible, rapidly progressive, and fatal disease causing death usually within 10 y of onset due to postsyncopal cerebral ischemia.

Primary neurodegenerative disease with primary autonomic failure. Parkinsonism-plus syndrome; however, Shy-Drager involves loss of vascular reflexes. There is secondary autonomic failure in Parkinson disease.

Clinical manifestations: Orthostatic hypotension, supine hypertension, parkinsonian symptoms, urinary and bowel dysfunction, impaired potency and libido, decreased sweating.

Autopsies showed diffuse involvement of the CNS and peripheral autonomic nervous system as well as corticobulbar and corticospinal tracts, basal ganglia, and cerebellum.

Difficult to treat the parkinsonian symptoms, as dopaminergic drugs may exacerbate orthostatic hypotension.