What is Diabetic Ketoacidosis

Ketoacidosis results from a lack of insulin. In practice it is usually due to: stopping insulin or reducing the dose either in error or deliberately, resistance to insulin during infections or other intercurrent illness, the unrecognised onset of Type 1 diabetes. The clinical onset of ketoacidosis occurs over hours or days. Symptoms of uncontrolled diabetes are always present. Vomiting in Type 1 diabetic patients is always serious. Patients usually consult their doctors during the preceding days, but the presence of uncontrolled diabetes is frequently overlooked. Diabetic control should always be assessed if a diabetic patient becomes unwell for any reason. Many cases of ketoacidosis could be prevented.

Causes of diabetic ketoacidosis

• Omission or reduction of insulin dose 27%

• Previously unknown diabetes 22%

• Infection 17%

• Miscellaneous 16%

• No cause found 18%

King’s College Hospital 1968

Management of diabetic ketoacidosis: sick day rules

During any illness or infection the blood glucose concentration tends to increase and diabetic control deteriorates. Most patients then need a larger dose of insulin than usual, and some who normally take tablets may need insulin just during the illness. The increased need for insulin occurs even when the appetite declines or vomiting begins. Every insulin treated patient should understand that insulin should never be stopped. Stopping or even reducing insulin during the course of an illness often leads to diabetic ketoacidosis. When a diabetic person is ill the normal insulin dose should be continued, carbohydrate taken in some palatable fluid form, and the blood tested regularly—four times a day if necessary. If blood glucose readings greater than 15 mmol/l are obtained the dose of insulin should be increased. Additional doses of insulin (about 8 units) may also be given at noon or bedtime when control is very poor. It is preferable to make these adjustments with short acting (soluble) insulin if this is available. If vomiting continues without remission for more than a few hours, admission to hospital for treatment with intravenous fluids and insulin is advisable to prevent ketoacidosis.

Assessment of blood or urine ketones during illness is helpful. Using the new blood ketone meters, readings of 1·0-3·0 mmol/l taken in conjunction with the blood glucose reading usually indicate the need for additional insulin; readings should be repeated within two to four hours. If they persist or increase above 3·0 mmol/l, specialist advice is required from the hospital clinic staff. Ketonuria can be detected using Ketostix, which are readily available.

Diabetic ketoacidosis pathophysiology -Recognising ketoacidosis

Dehydration is the most obvious clinical feature of patients with ketoacidosis. They are also drowsy, but rarely unconscious—“diabetic coma” is an inappropriate description; they are often overbreathing, but not usually breathless; their breath smells of acetone (though many people cannot smell this); and many

also have the gastric splash. In more severe cases patients are hypothermic (even in the presence of infection) and hypotensive. Hyperosmolar non-ketotic (HONK) patients are usually grossly dehydrated but without overbreathing or the smell of acetone. Inexperienced clinicians often have difficulty in recognising patients with this condition, especially when they seem deceptively well.

Diabetic Ketoacidosis Symptoms-Diagnosis of diabetic ketoacidosis

The diagnosis of ketoacidosis is confirmed by laboratory tests.

• Blood glucose

concentrations may range from slightly increased to extreme hyperglycaemia. The blood glucose concentration itself does not usually indicate the severity of the illness, although most patients are seriously unwell when it is greater than 30 mmol/l.

• Blood acid-base status

pH ranges from 6·9 to normal. The bicarbonate level is depressed.

• Plasma ketones

are easily detectable with a ketone meter and exceed 3·0 mmol/l.

• Urine test

shows heavy glycosuria and ketonuria.

• Electrolytes

The serum potassium concentration is either normal or raised, and very rarely low. This measurement is

vital, and life-saving treatment is needed to maintain potassium values in the normal range. The sodium

concentration is normal or reduced, and urea and creatinine concentrations are often raised through dehydration.

Blood count:

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