Diabetes, Type I (Insulin-Dependent)

Incidence in USA: 1.25 million.

Risk of requiring a CABG is increased 5–10 times in presence of ESRD, CHF, or autonomic neuropathy; without these conditions, the risk is 1-1½ times that of a normal person.

Autonomic neuropathy, gastroparesis, and sudden postop death.

Painless myocardial ischemia.

Atlantooccipital joint immobility.

Tight glucose control might be indicated in pregnant pts and those difficult to wean from bypass (in ECC as well as in the case of predictable global or focal CNS ischemia).

Endocrinopathy assoc with ESRD or ophthalmic, myocardial, and neuropathic disease

Blood sugar control per se not associated with increased periop risk in absence of

• Hypoglycemia

• Hyperosmolar coma

• Ketoacidosis

• CNS ischemia

• Pregnancy

• Extracorporeal circulation

Type I diabetes leads to deranged autoregulation of the CNS (with blood sugar at 250 mg/dL), kidney function (with blood sugar at 225 mg/dL), and function of the blood vessels (with blood sugar at 100 mg/dL and concomitant increased BP).

Need to control BP to decrease damage to these vessels and organs.

Check pt’s glucose log for degree of control.

Variable control may predict periop hypoglycemic episodes.

See also Diabetic Ketoacidosis.

Genetic predisposition to autoimmune destruction of glucose transporter on islet cells leads to increased blood glucose, which affects proteins via nonenzymatic glycosylation.

Swollen cells (sorbitol is oncotically active).

Increased viscous proteins (macroglobins), which impede blood flow.

Increased substrate for anaerobic metabolism.

Deranged autoregulation of blood flow.