History and exam

Key diagnostic factors

common

known diabetes or features of diabetes

Consider diabetic ketoacidosis (DKA) in:

  • Patients with known diabetes who are unwell[2][20]​​[63]​​

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

  • Patients with features of diabetes (increased thirst, polyuria, recent unexplained weight loss, or excessive tiredness) AND any of the following:[20]​​​[11]​​[63][65]​​[66]

    • Nausea

    • Vomiting

    • Abdominal pain​

    • Hyperventilation (Kussmaul respiration)

    • Dehydration (signs include dry mucous membranes, tachycardia, decreased skin turgor, slow capillary refill, and hypotension)

    • Reduced consciousness

nausea and/or vomiting

Suspect diabetic ketoacidosis if nausea and/or vomiting is present in a patient with known diabetes or in any patient with increased thirst, polyuria, recent unexplained weight loss, or excessive tiredness.[20][65]​ 

abdominal pain

Examine the abdomen for a possible cause of diabetic ketoacidosis (DKA), such as pancreatitis.​[42][64]​ DKA can both cause and mimic an acute abdomen.[66] Severity of abdominal pain correlates with the degree of acidosis.[1]​ DKA must be excluded prior to any emergency surgery.

  • Look for abdominal distension, which may indicate bowel obstruction.[99]

  • Palpate the abdomen to check for rebound tenderness and guarding caused by irritation of the peritoneum.[99]

  • Auscultate for bowel sounds.[100]

    • 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.[99]

    • Ensure you take a chaperone with you.

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

dehydration

Check for signs of dehydration. These include:[20]

  • Dry mucous membranes

  • Decreased skin turgor or skin wrinkling

  • Slow capillary refill

  • Tachycardia with a weak pulse

  • Hypotension

hyperventilation (Kussmaul respiration)

This is a late sign of diabetic ketoacidosis and occurs with more severe acidosis.[20][11]​​

Characterised by deep sighing respirations at a slow or normal rate.​[11]​​​[20]​​​​

reduced consciousness

Assess conscious level hourly using the Glasgow Coma Scale to monitor for cerebral oedema. Reduced consciousness is strongly associated with more severe diabetic ketoacidosis (DKA) and a worse prognosis.[2][89] [ Glasgow Coma Scale Opens in new window ] ​​

  • Mental status can range from alert in mild DKA to coma in severe DKA.[67]

  • Cerebral oedema can develop during treatment of DKA due to rapid correction of hyperglycaemia.[2]

    • Signs include headache, irritability, slowing pulse, rising blood pressure, and reducing conscious level. These may occur several hours after starting treatment.​[3]​​​[79]​​​

      • Papilloedema is a late sign of cerebral oedema.[3]​​

    • If neurological deterioration occurs, seek urgent input from the critical care team and administer mannitol without delay.[80]

    • Cerebral oedema has a mortality rate of 70%. It is most common in children and adolescents but can occur rarely in adults.[63]

presence of risk factors

Infection

  • This is the most common cause of diabetic ketoacidosis (DKA).​[2][20]

    • The most common infectious causes are pneumonia and urinary tract infection.[1][18]

Discontinuation of insulin (unintentional or deliberate)

  • This is the second most common cause of DKA.[20]​​[67]

  • 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.[20][63]​​

  • Younger patients with type 1 diabetes may omit insulin due to fear of hypoglycaemia, weight gain, eating disorders, or the stress of having a chronic disease. These factors may account for 20% of episodes of recurrent DKA.[93]

Inadequate insulin

  • Common reasons are:[68][69]

    • Malfunctioning insulin pen or pump.

    • Degradation of insulin due to storage at incorrect temperature.

New onset of diabetes[20]

  • A common cause of DKA.

Acute illness

  • Common causes include myocardial infarction, sepsis, and pancreatitis.​[42]

    • 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.[96][97]

Physiological stress

  • This includes pregnancy, trauma, and surgery.

  • Some women may develop DKA during menstruation.[94][95]

Practical tip

Diagnosis of DKA in pregnancy is often delayed because it can occur at lower blood glucose levels (including euglycaemic DKA) and faster than in non-pregnant patients.[2][98]​​

DKA in pregnancy may present with abdominal pain; always consider as a possible alternative to pre-term or term labour.[2]

DKA usually occurs in the second and third trimesters due to increased insulin resistance.[98]​ Pregnant women suspected of having DKA should receive care from both the obstetric and medical (or diabetes) teams.[2]

Past medical history

  • History of diabetes:

    • DKA is most common in people with type 1 diabetes but can also occur in those with type 2 diabetes.[11]​​

Drug history[20]

  • Drugs that may cause DKA include:[6][18][21][23]​​​[26]​​[31][47][48][49][50]​​[70]​​​[71][73]​​[72][74]​​​​​​

    • Corticosteroids (increase insulin resistance)

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

    • Sympathomimetics, such as dobutamine and terbutaline (alter glucose metabolism)

    • Atypical antipsychotics, such as clozapine, olanzapine, and risperidone (alter glucose metabolism)

    • Immune checkpoint inhibitors (cause insulin deficiency)

    • Cocaine, cannabis, and acute intoxication with alcohol 

    • Sodium-glucose cotransporter-2 (SGLT2) inhibitors (e.g., dapagliflozin, empagliflozin, canagliflozin, ertugliflozin) and the dual SGLT1/SGLT2 inhibitor sotagliflozin (prevent reabsorption of glucose and facilitate its excretion in urine)​

uncommon

hypothermia

Although concomitant infection is common, patients with diabetic ketoacidosis (DKA) are usually normothermic or hypothermic due to peripheral vasodilation. Severe hypothermia is associated with a mortality rate of 30% to 60%.[90] 

Practical tip

Fever is not a feature of diabetic ketoacidosis (DKA), but DKA may be caused by sepsis. Suspect sepsis as a cause of DKA if there is fever or hypothermia, (although hypothermia may also occur in patients with DKA of other aetiologies), hypotension, refractory acidosis, or lactic acidosis.[3]​​

Other diagnostic factors

common

acetone smell on breath

The patient’s breath smells like pear drops or nail varnish remover.[20] This is due to high ketone levels. 

Practical tip

Bear in mind that a significant proportion of people are unable to smell acetone even if it is present.

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