What is the proper workup for a patient with type 2 diabetes mellitus (T2DM) complaining of intermittent blurry vision and neuropathy who needs to be cleared for anesthesia?

Preoperative Workup for Type 2 Diabetes Patient with Blurry Vision and Neuropathy Requiring Anesthesia Clearance

The proper workup for a T2DM patient with intermittent blurry vision and neuropathy who needs anesthesia clearance must include HbA1c testing, comprehensive eye examination, neurological assessment, cardiovascular evaluation, and renal function tests. 1

Glycemic Control Assessment

• HbA1c level: Target <8% for elective surgeries 1
• Recent capillary blood glucose levels: Target 5-10 mmol/L (90-180 mg/dL) 1
• Consider postponing elective surgery if blood glucose >16.5 mmol/L (300 mg/dL) 1

Diabetic Complications Evaluation

Eye Examination

• Comprehensive dilated eye examination by an ophthalmologist or optometrist 2
  • Essential due to complaint of intermittent blurry vision
  • Assess for diabetic retinopathy, macular edema, and other ocular complications
  • If retinopathy is detected, determine severity (mild, moderate, severe nonproliferative, or proliferative) 2

Neuropathy Assessment

• Detailed neurological examination focusing on:
  • Peripheral neuropathy: sensory testing, deep tendon reflexes, muscle strength
  • Autonomic neuropathy: orthostatic blood pressure measurements, heart rate variability 2
  • Consider nerve conduction studies if clinical findings suggest significant neuropathy 3

Cardiovascular Evaluation

• 12-lead ECG at rest 2
• Assess for cardiac autonomic neuropathy which increases perioperative risk 2
• Consider cardiac stress testing if:
  • Patient has symptoms suggestive of cardiac ischemia
  • Poor functional capacity (<4 METs)
  • Multiple cardiovascular risk factors 2

Gastrointestinal Assessment

• Evaluate for gastroparesis (especially important for anesthesia risk) 2
  • Ask about symptoms: abdominal pain, bloating, vomiting
  • Increased risk of aspiration during anesthesia
  • May require rapid sequence induction regardless of fasting status 1

Renal Function

• Serum creatinine (for eGFR calculation) 2
• Urinary albumin/creatinine ratio (UACR) to assess for microalbuminuria 2
• Urinalysis to screen for proteinuria and other abnormalities 2

Medication Management

• Review current diabetes medications:
  • Hold metformin the evening before surgery 1
  • Hold oral glucose-lowering agents on the morning of surgery 1
  • For insulin users: give 75-80% of long-acting insulin dose 1
  • If on GLP-1 agonists (e.g., semaglutide): hold on day of surgery 1

Anesthesia-Specific Considerations

• Airway assessment with special attention to potential difficult intubation 1
• Consider endotracheal intubation rather than supraglottic airway devices, especially if gastroparesis is present 1
• Plan for aspiration precautions including rapid sequence induction if gastroparesis is suspected 1

Common Pitfalls and Caveats

1. Don't overlook gastroparesis: Even with prolonged fasting, patients with diabetic gastroparesis remain at high risk for aspiration during anesthesia 2, 1

2. Beware of silent cardiac disease: Diabetic patients may have silent myocardial ischemia due to autonomic neuropathy 2

3. Don't rely solely on symptoms: Early neuropathy and retinopathy can be asymptomatic despite significant pathology 3

4. Consider perioperative glucose management: Have a clear plan for intraoperative and postoperative glucose monitoring and management 1

5. Don't forget renal function: Diabetic nephropathy affects medication clearance and increases perioperative risk 2

By following this comprehensive preoperative workup, you can identify and address potential complications that may affect anesthesia administration and surgical outcomes in this T2DM patient with blurry vision and neuropathy.