‘Management of diabetic emergencies’ is the seventh standard of diabetes care in the NSF for diabetes (DoH, 2001). Its aim is ‘to minimise the impact on people with diabetes of the acute complications of diabetes’ and ‘to reduce the prevalence of the acute complications of diabetes through education of people with diabetes and all ‘frontline’ health professionals about how to avert and prevent diabetic ketoacidosis (DKA) and hyperosmolar non-ketotic (HONK) syndrome’ (DoH, 2001).
VOL: 100, ISSUE: 22, PAGE NO: 34
Samantha Rosindale, RGN, is senior diabetes nurse, Torbay Hospital, Torquay
‘Management of diabetic emergencies’ is the seventh standard of diabetes care in the NSF for diabetes (DoH, 2001). Its aim is ‘to minimise the impact on people with diabetes of the acute complications of diabetes’ and ‘to reduce the prevalence of the acute complications of diabetes through education of people with diabetes and all ‘frontline’ health professionals about how to avert and prevent diabetic ketoacidosis (DKA) and hyperosmolar non-ketotic (HONK) syndrome’ (DoH, 2001). People with diabetes do not have more illness than those without diabetes, although patients with type 1 diabetes are more prone to bacterial infection (National Electronic Library for Health (NELH), 2001). When diabetic patients become unwell, hyperglycaemia (blood sugar levels >10mmol/L) will result. Whether the cause of the intercurrent illness is a minor virus, an intercurrent infection or surgery, the patient’s usual self-management principles may be inadequate.
Insulin is a glucose-lowering hormone. To combat the source of the infection, counter-regulatory (or glucose raising) hormones such as glucagon are released and oppose insulin action, stimulating further glucagon release. The hyperglycaemia is the consequence of a relative or absolute deficiency of insulin in the presence of a relative or absolute excess of glucagon. When the insulin deficiency is extreme, these hormonal abnormalities cause the liver to release glucose and interfere with the action of insulin, resulting in hyperglycaemia and the tendency to develop ketoacidosis (Cryer, 1985). DKA is an avoidable, potentially life-threatening complication of type 1 diabetes. It is a combination of hyperglycaemia, acidosis and ketosis with the primary cause being insulin deficiency, either relative or absolute. The distinction between DKA and HONK is somewhat arbitrary but in HONK hyperglycaemia tends to be more extreme, and acidosis and ketosis absent or much less marked (Marshall et al, 1992). If hyperglycaemia is not managed correctly and glucose levels rise uncontrollably, DKA or HONK can develop in patients (especially older people) with type 2 diabetes. Both these conditions have a high mortality rate. Estimates from DKA are 5-10 per cent and the risk increases with age, hypotension, and urea with a low pH. It is present in 20-25 per cent of newly diagnosed cases (Marshall et al, 1992). The incidence of HONK is approximately one-sixth to one-tenth that of DKA and carries a mortality rate of 30-35 per cent (Wallace and Matthews, 2002). To avoid these diabetic emergencies patients are educated to follow specific guidance. This advice is commonly known as ‘sick-day rules’ and its principle is to prevent glucose levels rising and halt the onset of DKA or HONK and subsequent hospital treatment.
As there is never a right time to be unwell and it often occurs when least expected, education for the patient with diabetes should be as much about preparation and planning on how they would manage their diabetes during the period of illness, as well as actually coping at the specific time. Rehearsing scenarios can help patients remember with greater clarity what they need to do when ill, as well as learning these skills at a practical level. A few ‘stock cupboard’ items are essential to ensure the patient is adequately prepared. These could include: - Long-life fruit juice; - Bottle of ordinary ‘Lucozade’ or non-diet fizzy drink; - Two 2L bottles of still water; - Soup; - Ice-cream; - Unopened box of blood glucose monitoring strips; - Unopened box of ketone strips (if on insulin). All items should have their expiry dates checked (especially the last two items) every six months. Written information on sick-day rules should be kept with these.
Patients should be advised that during illness they may be unable or unwilling to eat. In these circumstances it is a common mistake for patients to omit diabetic medication (tablets or insulin) because of a perceived risk of hypoglycaemia (capillary blood sugar below 4mmol/L). Hyperglycaemia and not hypoglycaemia will be present when someone with diabetes has an intercurrent illness and the omission of medication will put them at risk of developing DKA or HONK. All patients with diabetes who are unwell with hyperglycaemia should never omit their usual doses of insulin or tablets even if not eating. Patients should be encouraged to eat a normal diet if possible. However, if their appetite is minimal or they are unable to eat, then their meals can be replaced with sugary fluids or other foods as listed in Table 1. The amounts shown are equivalent to 10g of carbohydrate and will help ensure the patient is still having her or his full carbohydrate allowance to balance the insulin/tablets that have already been taken. The amounts shown in Table 1 should be taken hourly. It should be possible for an adequate carbohydrate intake to be maintained orally by a selection of these foods. All foods now have their carbohydrate content printed on the label and a simple calculation will convert other foods into 10g equivalents if the patient requires further alternatives. Fizzy drinks are probably better sipped slowly rather than being gulped down. Drinking enough fluids is extremely important because dehydration can occur quickly (especially in the presence of diarrhoea, fever, or vomiting) and ketone levels can begin to rise. The patient should be encouraged to drink at least a glass of water every hour, aiming for at least three litres every 24 hours.
Monitoring glucose and ketone levels
Capillary blood glucose levels will fluctuate during the period of illness and patients should be advised that they need to monitor their blood glucose levels every four hours as a minimum, and be prepared to increase monitoring to two-hourly if the levels keep rising (Tables 2-3). Patients who perform urine testing for the presence of glucose (glycosuria) should be advised that if their urinalysis tests are positive for glucose they should also monitor every four hours. Patients with type 1 or type 2 diabetes treated with insulin need to check their urine for ketones (ketonuria). If ketonuria is present it is because there is not enough insulin in the blood. Testing for ketones should be done once or twice a day and should be increased if ketonuria is present (Table 2). When patients start to feel better they should still monitor their blood and/or urine at this level until: - They can follow their regular meal pattern; - Their capillary blood glucose levels are consistently lower than 13mmol/L; - Their urine shows no presence of glucose; - Their urine shows no presence of ketones. It can be a nuisance for the patient to do so much monitoring while feeling unwell but it is the only way to keep track of the diabetes control. If the patient feels that she or he cannot do this then a relative or friend may be able to help.
There are no hard and fast rules for insulin dose changes as each individual patient will have different requirements (NELH, 2001). Whatever the type of insulin, patients should take their usual dose at the usual time. Patients who take short-acting insulin (such as NovoRapid, Actrapid, Humalog, Humulin S) may have been advised by their specialist diabetes team to add extra units depending on their capillary blood sugar results, for example for a blood glucose level >10 but <15mmol/L take an extra four units of NovoRapid. These doses should be agreed with the patient after individual assessment and in accordance with local guidelines. Patients taking pre-mixed insulin (such as Humulin M3, Humalog Mix 25, NovoMix 30) or a long-acting insulin (for example Insulatard, Humulin I) could increase their doses by 2-4 units at each usual injection time. However, this may not control the hyperglycaemia because these types of insulin may not be able to work quickly enough. These patients should be encouraged to seek medical advice and may need to be prescribed short-acting insulin for the remainder of the illness. People with type 2 diabetes should continue to take their medication as prescribed. The prescription may need to be increased if this is not controlling glucose levels but this should only be done with medical guidance. If patients cannot tolerate their tablets they should seek advice immediately from their GP or diabetes specialist nurse as they may need temporary admission to hospital for insulin therapy. On occasion, despite following advice, patients may be unable to stop their sugar or ketone levels from rising. In the circumstances outlined in Table 4 these patients should seek further advice.
Tables 3-4 may be useful as a quick reference guide but local guidelines should be referred to. Nurses should understand the importance of revising patients’ knowledge of sick-day rules at least annually. They should also give feedback after an episode so that the person with diabetes may reflect on how she or he managed. - This article has been double-blind peer-reviewed.