DIABETES MELLITUS IN ANAESTHESIA

SHARANIA MANIVANNAN

11 2014 182

ABSTRACT

Anaesthesiologists frequently encounter patients

with diseases of the endocrine system, in particular

diabetes mellitus. The major risk factors for people

with diabetes undergoing surgery are the associated

end-organ diseases: cardiovascular autonomic

neuropathy, joint collagen tissue, and immune

deficiency.

INTRODUCTION

Patients with diabetes have a significantly

increased risk of premature mortality and an

increased risk of microvascular and cardiovascular

complications and are often sicker than most non-

diabetic patients and therefore place a

proportionally larger burden on anaesthetic

services.

INTRODUCTION

Major risk

factor

Cardiovascular dysfunction

Renal insufficiency

Joint stiffness

Neuropathies

ANAESTHETIC AGENTS AND DIABETES MELLITUS

Affect glucose homeostasis peri-operatively by decreasing catabolic hormone secretion

Use of succinylcholine should be avoided if patients have elevated baseline serum potassium concentrations

Infusions of midazolam shown to decrease ACTH and cortisol secretion

Benzodiazepines reduce SS but increase growth hormone secretion, resulting in decrease in the hyperglycaemic response to surgery.

Morphine needs to be reduced to 75% of the standard dose in patients with a GFR of 10–50 ml/min, and 50% in patients with a GFR < 10 ml/min

ANAESTHETIC AGENTS AND DIABETES MELLITUS

Fentanyl is primarily metabolised in the liver by CYP3A4, making it an attractive choice for patients with renal dysfunction.

Premedication with clonidine in DM 2 90 minutes before surgery improved blood glucose control hence decreasing insulin requirement.

Halothane and sevoflurane, produce greater negative inotropic effects in diabetic patients than in non-diabetic patients.

ANAESTHETIC TECHNIQUES

Spinal, epidural or other regional blockade

modulate the secretion of catabolic

hormones and insulin secretion.

No evidence suggests that one anaesthetic

technique or another affects mortality or

morbidity in diabetic patients.

SPINAL ANAESTHESIA

REGIONAL ANAESTHESIA

Advantages

Allow patient to remain conscious and decrease surgical stress response

Decreases blood loss and leads to a decreased risk

of thromboembolism.

Disadvantages

Cardiovascular instability

Exacerbation of peripheral neuropathy since diabetic patients more susceptible

to anaesthetic toxidity

BLOCK OF THE DEEP PERONEAL NERVEAlong the imaginary line - between the medial and lateral malleolus, feel for tendons of the anterior tibialis and extensor hallucis longus muscle. The muscle tendon can be easily palpated if the patient is asks to dorsiflex his/her foot. Insert the needle between the two tendons with the point of the needle towards the tibia. A loss of resistance should be detected as the needle pierces the flexor retinaculum, inject 5 ml of 0.5-1% lidoocaine with adrenaline

PERIOPERATIVE MANAGEMENT

It is generally recommended to aim for

normoglycaemia in hospitalised patients.

The main concern of the anaesthesiologist in

the peri-operative management of diabetic

patients has always been the avoidance of

harmful hypoglycaemia; made more difficult

by the reduced level of consciousness

masking its signs and symptoms.

PERIOPERATIVE MANAGEMENT

Glucose levels > 200 mg/dL are considered

detrimental and require treatment.

It is important to exclude diabetic

ketoacidosis and non-ketotic hyperglycaemic

hyperosmolar states in patients presenting

with very high glucose levels; surgery in the

presence of such conditions carries a high

mortality.

SUMMARY

Endocrine disorders should be identified and

evaluated before surgery. Diabetes affects

multiple organ systems, and the peri-

operative effects of diabetes can be

profound. Peri-operative management should

be based on the type of diabetes, end organ

dysfunction and the desired degree of

glucose control in the peri-operative periods.