History and exam

Key diagnostic factors

Consider DKA in: 

  • Patients with known diabetes who are unwell[2][42][17]

    • DKA is most common in people with type 1 diabetes but can also present in those with type 2 diabetes.[42][46]

  • Patients with features of diabetes AND any of the following:[17][48]

    • Nausea and vomiting

    • Abdominal pain[2][49]

    • Hyperventilation (Kussmaul's respiration)[50]

    • Dehydration

    • Reduced consciousness.

Features of diabetes are increased thirst, polyuria, recent unexplained weight loss, or excessive tiredness.[17][48] 

Suspect DKA if this is present in a patient with known diabetes, increased thirst, polyuria, recent unexplained weight loss, or excessive tiredness.[17][48] 

Examine the abdomen for a possible cause of DKA, such as pancreatitis.[47][15][30] DKA can both cause and mimic an acute abdomen.[49] 

  • Look for abdominal distension, which may indicate bowel obstruction.[83]

  • Palpate the abdomen to check for rebound tenderness and guarding caused by irritation of the peritoneum.[83]

  • Auscultate for bowel sounds.[84]

    • Hyperactive ‘tinkling’ bowel sounds may be present in early bowel obstruction.

    • Reduced or absent bowel sounds may be present in late bowel obstruction, perforated viscus, haemoperitoneum, or any cause of peritoneal inflammation.

  • Perform a rectal examination.[83]

    • Ensure you take a chaperone with you.

    • Assess for occult or frank blood, pain, or a mass.

Check for signs of dehydration. These are:[17]

  • Dry mucous membranes

  • Decreased skin turgor or skin wrinkling

  • Slow capillary refill

  • Tachycardia with a weak pulse

  • Hypotension.

This is a late sign of DKA and occurs with more severe acidosis.[17][50]

Characterised by deep sighing respirations at a slow or normal rate.[17][50]

Assess conscious level hourly using the Glasgow Coma Scale to monitor for cerebral oedema. Reduced consciousness is strongly associated with more severe DKA and a worse prognosis.[67][42][ Glasgow Coma Scale ]

  • Mental status can range from alert in mild DKA to coma in severe DKA.[53]

  • Cerebral oedema can develop during treatment of DKA due to rapid correction of hyperglycaemia.[42]

    • Signs include headache, irritability, slowing pulse, rising blood pressure, reducing conscious level. These may occur several hours after starting treatment.[51][61]

      • Papilloedema is a late sign of cerebral oedema.[51]

    • Involve immediate critical care input and give mannitol.[62]

    • Cerebral oedema has a mortality rate of 70%. It is most common in children and adolescents but can occur in adults.[2]

Infection

  • This is the most common cause of DKA.[46][42][53][26][33][71][35][36]

    • The most common causes are pneumonia and urinary tract infection.

Discontinuation of insulin (unintentional or deliberate)

  • This is the second most common cause of DKA.[17][53][26]

  • Ask sensitively about reasons for deliberate discontinuation of insulin, which may include fear of weight gain or hypoglycaemia, financial barriers, and psychological factors such as needle phobia and stress.[2][17]

  • Younger patients with type 1 diabetes may omit insulin due to fear of hypoglycemia, weight gain, eating disorders, or the stress of having a chronic disease. These factors may account for 20% of recurrent DKA.[72]

Inadequate insulin

  • Common reasons are:

    • Malfunctioning insulin pen or pump[54][55]

    • Degradation of insulin due to storage at incorrect temperature.[55]

New onset of diabetes[17]

  • A common cause of DKA.

Acute illness

  • Common causes include myocardial infarction, sepsis, and pancreatitis[15][30]

    • Maintain a high level of suspicion for myocardial infarction as patients with diabetes often present with atypical symptoms.

Practical tip

Some patients with diabetes may present with a ‘silent myocardial infarction’ with no or minimal chest pain. This is thought to be due to cardiac autonomic dysfunction.[75][76]

Physiological stress

  • This includes pregnancy, trauma, and surgery.

  • Some women may develop DKA during menstruation.[73][74]

Practical tip

Diagnosis of DKA in pregnancy is often delayed because it can occur at lower blood glucose levels and faster than in non-pregnant patients.[77]

DKA usually occurs in the second and third trimesters due to increased insulin resistance.[77]

Past medical history

  • History of diabetes:

    • DKA is most common in people with type 1 diabetes but can occur in those with type 2 diabetes.[46]

Drug history[17]

  • Drugs that may cause DKA include:

    • Corticosteroids (increase insulin resistance)[57]

    • Thiazides (unclear cause but may increase insulin resistance, inhibit glucose uptake, and decrease insulin release)

    • Sympathomimetics (alter glucose metabolism)[26]

    • Second-generation antipsychotics (alter glucose metabolism)[58]

    • Immune checkpoint inhibitors (cause insulin deficiency)[59]

    • Cocaine, cannabis, and acute intoxication with alcohol (DKA is associated with cocaine use but the mechanism is unclear)[56][60]

    • SGLT2 inhibitors (prevent reabsorption of glucose and facilitate its excretion in urine).[21][22]

Severe hypothermia is associated with a mortality rate of 30% to 60%.[68] Mild hypothermia may be seen in some patients with DKA due to peripheral vasodilation.[46]

Practical tip

Fever is not a feature of DKA but DKA may be caused by sepsis. Suspect sepsis as a cause of DKA if there is fever or hypothermia, hypotension, refractory acidosis, or lactic acidosis.[51]

Other diagnostic factors

The patient’s breath smells like pear drops or nail varnish remover.[17] This is due to high ketone levels. 

Practical tip

A significant proportion of people are unable to smell acetone even if it is present.

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