Diabetes (basics)

Multi-system disease severity related to blood sugar control

2% prevalence
Absence of insulin: type I

Older patients with some insulin (obese): type II. Usually treated with oral hypoglycemics
Surgery related to the complications: sepsis, skin ulceration

Complications

Vascular: Ischemic heart disease and cerebrovascular complications. Hypotension poorly tolerated
Hypertension: strongest correlate of autonomic neuropathy
Autonomic neuropathy may result in sudden tachycardia with hypotension and cardiac arrest. It also causes delayed gastric emptying and a risk of aspiration
Cardiomyopathy: leading to left ventricular dysfunction
Nephropathy: increased risk of renal failure and microalbuminemia
Infection: sepsis is a significant cause of peri-operative morbidity

Complications 2

Respiratory: decreased FEV₁ and FVC, higher incidence of chest infections and COPD, particularly in obese patients
Retinopathy: high risk of vitreous hemorrhage during hypertensive procedures
Medical conditions: hyperpituitarism, hyperthyroidism, obesity, stress, pregnancy
Drugs causing diabetes: corticosteroids

Assessment

Assess diabetic control - delay surgery if poorly controlled unless it is life-saving.
Orthostatic hypotension and reduced HR response to Valsalva suggest autonomic neuropathy.
Major surgery: insulin, glucose, potassium
Type I patients: no long-acting insulin but should be managed on a subcutaneous sliding scale
Type II minor surgery: omit morning oral hypoglycemic and measure blood glucose regularly
Ideally, it's the first on the list.

Diabetic Ketoacidosis (DKA)

Large-volume resuscitation with normal saline
IV insulin infusion administered according to a sliding scale
CVP, urinary output, acidosis, blood glucose, and potassium should be measured hourly
Large amounts of potassium can be needed
Allow surgery once biochemical improvement
Some surgical conditions need to be treated to allow control

Conduct

Gastric stasis: Rapid sequence induction is necessary
Avoid lactate-containing solutions such as Hartmann’s (lactate is converted to bicarbonate)
Regional technique?? (document neuropathy)
Avoid hypotension and myocardial depression
Blood glucose 7-10 mmol/L = 120-180 mg/dL
Mild hyperventilation may be beneficial

Post-op

Continue monitoring of blood glucose