Overview

• Hyperglycaemic emergencies include diabetic ketoacidosis (DKA) and hyperosmolar hyperglycaemic syndrome (HHS)

• Both require immediate treatment in hospital with insulin and fluid replacement

• In DKA the associated acidosis leads to loss of total body potassium requiring close monitoring and intravenous potassium replacement during rehydration

• Hyperviscosity may lead to thrombosis particularly in older patients with HHS

• Following recovery patients require review of the treatment regimen and close follow-up to prevent recurrence

• Patients admitted to hospital for elective procedures should be managed according to readily available protocols to optimise outcomes

• Involvement of the diabetes specialist team is important when problems arise in hospitalised patients

Introduction

A patient with severe hyperglycaemia can appear to be relatively well, so that potentially life-threatening diabetic ketoacidosis (DKA) or hyperosmolar hyperglycaemic syndrome (HHS) may go unrecognised. Thus, although a patient with significant hyperglycaemia can often be managed quite successfully out of hospital by experienced clinicians, if in doubt it is best to err on the safe side and send the patient to hospital.

Preventing diabetic ketoacidosis (DKA)

When a patient with diabetes presents with an acute illness, one should always assess the glycaemic control. During intercurrent infection, it is necessary for the patient to take larger doses of insulin than usual. Patients are usually taught this but they often require support, especially if they have not dealt with a similar situation before. Often whilst taking antibiotics, the patients may have lost appetite and may feel that as they are eating less they should take less insulin. Unfortunately, some patients even stop insulin altogether during illness and this is very likely to lead to diabetic ketoacidosis. If the patient is unable to eat or drink then clearly intravenous fluids and insulin will be required and the patient needs to go to hospital. However, for those patients who are managing an illness at home, regular frequent blood glucose monitoring and additional insulin should be taken as informed by the blood glucose monitoring results. For those taking twice daily pre-mixed insulin, short-acting insulin is valuable, if taken additionally.

Patients who have had diabetic ketoacidosis may also have been given blood or urine ketone meters or ketosticks. These are useful for indicating the onset of ketoacidosis. Sometimes ketoacidosis may be a presenting feature of type 1 diabetes or rarely late in type 2 diabetes.

Clinical features of ketoacidosis

Dehydration and tachypnoea are frequently seen early in DKA. Some clinicians may be able to smell ketone odour on the patient's breath. In more severe DKA, vomiting and drowsiness also develop.

Diagnosis

Blood glucose is typically very high, but is sometimes only modestly raised, especially when the patient has not been eating regularly. In these cases it is important to recognise that the degree of hyper-glycaemia is not an index for the severity of the condition. Urine tests for ketones will be positive and plasma ketones will be elevated. Blood gases will show acidosis and reduced bicarbonate. Diabetic ketoacidosis is associated with severe electrolyte abnormalities, particularly of serum potassium. Electrolytes will need to be monitored frequently during the treatment of DKA as there is a net whole-body deficit of potassium and potassium replacement is essential and guided by frequent electrolyte measurements. Full blood counts will usually reveal leukocytosis; however, this does not necessarily imply infection. Similarly, serum amylase is often elevated but does not necessarily indicate pancreatitis. Further investigations are guided by additional clinical features of the particular patient, a chest x-ray is often carried out to exclude a chest infection. Urine analysis and urine culture may be required to exclude urinary tract infection. Blood culture may also be indicated if septicaemia is suspected. The need for further imaging is determined by the clinical presentation.

Treatment

Patients with diabetic ketoacidosis require high-intensity nursing on a one-to-one basis and this is usually achieved in a High Dependency Unit, or if extremely ill and requiring ventilation in an ITU setting.

Fluid and electrolyte management is key to successful treatment of DKA. This is achieved using intravenous saline and the table shows a suitable regimen. Care should be taken in patients with cardiac disease and post-myocardial infarction. In such patients a central venous line and monitoring of central venous pressure (CVP) will be required. Fluid is changed to 5% dextrose once blood glucose has dropped below 11 mmol/l, this will also enable more insulin to be administered as soluble insulin, through a syringe driver and a suitable regime used at the University Hospital, Coventry is shown in Figure 7.1. In severe cases soluble insulin is given IM as a bolus as well. It is important that nursing staff check the equipment regularly as kinks in the line for the fluids or insulin can complicate therapy.

Potassium replacement is nearly always required in patients with DKA, with the possible exception of patients who have advanced renal disease. A suitable regime is also shown in Figure 7.1. Regular urea and electrolyte measurements should be requested and potassium should be maintained between 4-5 mmol/l.

Diabetic Ketoacidosis This is an EMERGENCY START INSULIN IMMEDIATELY

Diabetic Ketoacidosis This is an EMERGENCY START INSULIN IMMEDIATELY

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