Diabetes Mellitus

Summary

• Elevated perioperative blood glucose >10mmol/L is associated with poor outcomes
• Poor blood glucose control needs screening for microvascular and macrovascular disease including cardiovascular and renal comorbidities
• Extremely high blood glucose levels can cause ketoacidosis or hyperosmolar hyperglycemic state
• All patients with history of DM must have HbA1c measured within 3 months
• Any patient presenting for elective surgery with HbA1c > 8% requires OPD referral for diabetes management and delay of surgery until BG management improves (at least 2 weeks)

Background

• Diabetes Mellitus (DM) is an endocrine, metabolic disorder marked by high levels of blood glucose. The incidence of DM in Kenya is 3.3% and increasing. Three classifications of diabetics exist:

Type 1 Diabetes

• an immune-mediated destruction of pancreatic beta cells causes a total reduction in endogenous insulin

Type II Diabetes

• patients experience increasing insulin resistance for the level of endogenous insulin, sometimes in combination with failure of pancreatic beta cells

Gestational Diabetes

• hyperglycemia occurs in the second or third trimester of pregnancy

Risk Factors

• Obesity: BMI>30, waist circumference >94cm (men); >90cm (Asian men); >80cm (all women)
• Hypertension or cardiovascular disease
• Frequent infections, particularly skin infections
• History of gestational diabetes (every 2 years)
• FH of diabetes - parent, sibling (every 2 years)
• If taking drugs that can cause high blood glucose (corticosteroids >1m, ARVs, antipsychotics)
• TB

Diagnosis

• If symptomatic: One abnormal result – HbA1c >6.5 OR Fasting Sugar >7
• If asymptomatic: Two abnormal results at two different times - HbA1c >6.5 OR Fasting sugar >7

Anaesthesia Evaluation

1. In patients with DM presenting for anaesthesia evaluation, ensure that an HbA1c is available within the last 3 months
2. For HbA1c < 8%, continue current management and proceed with evaluation
3. For HbA1c > 8%, refer to OPD for medication adjustment and postpone surgery until patient demonstrates improved glycemic control
4. Screen patient history and exam for cardiovascular and renal disease. Further labs and studies dictated by patient history, exam, and surgical severity with a lower threshold to obtain ECG or echo.

Medication Management

Kijabe Hospital OPD Guidelines