Diabetic ketoacidosis

Diabetic ketoacidosis (DKA) is defined as the presence of a metabolic acidosis (venous bicarbonate less than 15 mmol/L or pH less than 7.3) and significant ketosis (plasma beta hydroxybutyrate greater than 3 mmol/L or ketonuria greater than 2+ on standard urinalysis sticks) in the presence of a random plasma glucose greater than 11 mmol/L or known diabetes. The latter criterion is important as the entity of normoglycaemic DKA is well recognised and is a diagnostic pitfall for the unwary, especially in pregnancy.

Is the patient vomiting? 

Vomiting is a classical presenting symptom of DKA and is a marker that the patient requires hospitalisation.

Does the patient have abdominal pain?

Abdominal pain is a classical presenting symptom of DKA and usually resolves as the acidosis resolves.

However, sometimes it is mistakenly diagnosed as a surgical emergency. This is avoidable by performing urinalysis.

Once the diagnosis of DKA is made it should be treated first unless there is unequivocal evidence of a surgical emergency mandating urgent laparotomy. Fortunately this combination of circumstances is rare.

When did the patient last take insulin?

Omission of doses of insulin is a common precipitant of DKA. This may be intentionally or may occur mistakenly when the patient has an intercurrent illness causing vomiting or anorexia.

Under these circumstances patients understandably miss insulin to avoid hypoglycaemia. However intercurrent illness actually raises requirements for insulin and the best way to avoid this scenario is to educate patients assiduously about 'sick day rules'.

Is the patient known to have diabetes?

DKA is still the presenting feature of diabetes in a small proportion of cases and thus there may not necessarily be a past medical history of diabetes.

What type of diabetes does the patient have?

While DKA is classically regarded as the hyperglycaemic emergency of T1DM, ketosis prone T2DM is increasingly recognised and it has also been reported in gestational diabetes.

In the acute situation, this consideration should have relatively little impact on emergency management and the patient should be managed for DKA regardless.

Has the patient had a distinct intercurrent illness?

Infection is a common precipitant of DKA, thus symptoms such as fever, cough, dyspnea and dysuria should be sought.

Is the patient pregnant?

Pregnancy is an inherently ketosis-prone state and is a high-risk time for DKA in females with T1DM.

Has there been any technical difficulty with insulin delivery?

Not infrequently patients develop DKA without an apparent cause and despite their best efforts to combat the rising glycaemia and progressing ketosis. In such cases it sometimes later transpires that the vial of insulin in their insulin pen was broken, or the pen itself was defective, or the insulin was from a technically faulty batch (rare) or that some other such technical problem was present all along.

Reviewing these aspects of management after DKA has resolved is important.

When did the patient last present with DKA?

Recurrent DKA is a particularly worrying sign as it often heralds some fundamental problem with diabetes self-management.

It is therefore important that the patient is reviewed by a diabetic specialist and/or specialist nurse after resolution in order that such underlying problems may be identified and addressed. Such problems often involve gaps in the patient’s knowledge/education about self-management, sick day rules and the like.

Sometimes there is a deep-seated psychological problem about their diabetes. Sometimes it is a manifestation of chronically sub optimal control, or even an unrecognised second pathology such as coeliac disease, thyroid dysfunction or Addison’s disease.

Has the patient been drinking alcohol to excess?

Alcoholic binges are another common precipitant of DKA. 

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