Best Practice Topic Updates

Hyperosmolar hyperglycaemic state

2012-02-13

Hyperosmolar hyperglycaemic syndrome (HHS), also known as non-ketotic hyperglycaemic hyperosmolar syndrome (NKHS), is characterised by profound hyperglycaemia (glucose >33.3 mmol/L [>600 mg/dL]), hyperosmolality (effective serum osmolality >320 mmol/L [>320 mOsm/kg]), and volume depletion in the absence of significant ketoacidosis (pH >7.3 and HCO3 >15 mmol/L [>15 mEq/L]), and is a serious complication of diabetes. HHS may be the first presentation of type 2 diabetes. Although both HHS and diabetic ketoacidosis (DKA) are often discussed as distinct entities, they represent 2 points on the spectrum of metabolic derangements in diabetes, both HSS and DKA being characterised by relative or absolute insulin deficiency combined with increased counter-regulatory hormones. Approximately 33% of patients with hyperglycaemic crises present with a mixed picture of DKA and HSS.

Benign tongue lesions

2012-02-13

Fissured tongue is a common benign clinical condition of unknown aetiology usually affecting the dorsum of the tongue. On physical examination, numerous grooves or fissures are seen on the dorsal surface of the tongue. Usually these multiple asymptomatic grooves are 2 mm to 3 mm in depth but may extend up to 6 mm. They may occur in isolated areas of the tongue or may cover the entire dorsum.

Type 2 diabetes in children

2012-02-13

Type 2 diabetes mellitus (T2DM) is a progressive disorder due to a deficit in both insulin secretion and insulin action leading to abnormal glucose metabolism and related metabolic derangements.

Inpatient glycaemic management

2012-02-13

Inpatient glycaemic management refers to identifying and treating hyperglycaemia in the setting of acute illness in hospitalised patients with either pre-existing diabetes or new-onset hyperglycaemia. This may occur in the ICU or in the general ward, and evidence and guidelines differ between these settings. The 3 groups of patients to consider are the following:

Type 2 diabetes in adults

2012-02-13

Type 2 diabetes mellitus is a progressive disorder defined by deficits in insulin secretion and action that lead to abnormal glucose metabolism and related metabolic derangements. Although the aetiologies of type 1 and type 2 diabetes differ dramatically, both lead to hyperglycaemic states, and both share common macrovascular (coronary heart, cerebrovascular, and peripheral vascular disease) and microvascular (retinopathy, nephropathy, and neuropathy) complications. Type 2 diabetes is usually diagnosed based on screening. It is preceded by a state of pre-diabetes, which may be clinically detected by a fasting plasma glucose of 5.6 mmol/L to 6.9 mmol/L (100 to 125 mg/dL). Diabetes diagnosis is based on 2 confirmed values of: fasting plasma glucose >6.9 mmol/L (125 mg/dL); HbA1c of 6.5% or greater; or (less commonly) abnormal glucose tolerance test results, or a random plasma glucose of ≥200 mg/dL plus symptoms of hyperglycaemia. .

Diabetic retinopathy

2012-02-13

Diabetic retinopathy is the retinal consequence of chronic progressive diabetic microvascular leakage and occlusion. It eventually occurs to some degree in all patients with diabetes mellitus. There are two types: non-proliferative and proliferative. Non-proliferative diabetic retinopathy (NPDR) is the early stage of the disease and is less severe. Blood vessels in the eye may leak fluid into the retina, which leads to blurred vision. Proliferative diabetic retinopathy (PDR) is the more advanced form of the disease. New blood vessels start to grow in the eye (neovascularisation), which are fragile and can haemorrhage. This may cause vision loss and scarring of the retina.

Metabolic syndrome

2012-02-13

Metabolic syndrome, originally described by Reaven in 1988 as "syndrome X" or "insulin resistance syndrome", is a cluster of common abnormalities, including insulin resistance, impaired glucose tolerance, abdominal obesity, reduced HDL-cholesterol levels, elevated triglycerides, and hypertension. No known common cause unifies its components. The condition reflects the sedentary lifestyle, overnutrition, and resultant excess adiposity of the modern world. Metabolic syndrome is associated with endothelial dysfunction and atherosclerosis resulting in an increased risk of cardiovascular disease (CVD) and type 2 DM. The main utility of diagnosing metabolic syndrome is the identification of people at high risk of CVD beyond LDL-cholesterol levels. However, whether a diagnosis of metabolic syndrome provides more useful information than its individual components regarding cardiovascular risk is greatly controversial.

Diabetic neuropathy

2012-02-13

Diabetic neuropathy (DN) is a chronic complication of diabetes (type 1 or type 2), characterised by the presence of symptoms, and/or signs of peripheral nerve dysfunction, and/or autonomic nerve dysfunction. It is diagnosed after the exclusion of other causes. Frequently, however, people with DN are asymptomatic.

Chlamydia pneumoniae infection

2012-02-13

(an obligate intracellular bacterium) is a frequent respiratory pathogen in humans that occurs worldwide and in all age groups. It is a major cause of community-acquired pneumonia. Reliable diagnosis of respiratory infection due to and investigation of its role in chronic diseases remain difficult due to the absence of well-standardised and commercially available diagnostic tests.

Gestational diabetes

2012-02-13

Gestational diabetes mellitus (GDM) is defined as any degree of glucose intolerance with onset or first recognition during pregnancy. It is usually recognised at 24 to 28 weeks of gestation on the basis of abnormal glucose tolerance testing. Additionally, pregnancy can be complicated by established type 1 or type 2 diabetes.

Diabetic nephropathy

2012-02-13

Diabetic nephropathy (DN) is defined as macroalbuminuria (albumin to creatinine ratio [ACR] >34 mg/mmol [300 mg/g]), or microalbuminuria (ACR 3.4 to 34 mg/mmol [30 to 300 mg/g]) associated with retinopathy (type 1 or type 2 diabetes) and/or >10 years' duration of type 1 diabetes mellitus. In most patients with diabetes, chronic kidney disease (CKD) can be attributable to diabetes if these criteria are met. Other cause(s) of CKD should be considered in the presence of any of the following circumstances: absence of diabetic retinopathy, rapidly decreasing GFR, presence of active urinary sediment (e.g., cellular casts in urine), or signs or symptoms of other systemic disease. The characteristic clinical presentation is progressive albuminuria, hypertension, and decline in GFR in a long-standing (duration >10 years) diabetic patient. The diagnosis is most conclusively made by kidney biopsy, though it is rarely necessary.

Overview of acute coronary syndrome

2012-02-13

Acute coronary syndrome (ACS) refers to acute myocardial ischaemia caused by atherosclerotic coronary disease and includes ST-elevation myocardial infarction (STEMI), non ST-elevation MI (NSTEMI), and unstable angina (UA). These terms are used as a framework for guiding management.

Obesity in children

2012-02-13

Obesity is a condition of excessive body fat or adiposity which exceeds healthy limits. The most widely accepted method to screen for excess adiposity is calculation of BMI. Abnormal BMI cut-offs in children are determined by age- and gender-specific percentiles based on growth charts, as the amount of body fat changes with age and differs between boys and girls. Worldwide, the definition of overweight and obesity changes; however, a BMI >85th percentile is defined as overweight or at risk for overweight in the US and UK, a BMI ≥95th percentile is variably defined as obesity or overweight, and a BMI >99th percentile is defined as morbid obesity. For children under 2 years of age, BMI percentiles are not available; thus, obesity may be defined as a weight ≥95th percentile for height.

Diabetic ketoacidosis

2012-02-13

Diabetic ketoacidosis (DKA) is an acute metabolic complication of diabetes that is potentially fatal and requires prompt medical attention for successful treatment. It is characterised by absolute insulin deficiency and is the most common acute hyperglycaemic complication of diabetes.

Diabetic cardiovascular disease

2012-02-13

Diabetes mellitus is a group of metabolic diseases, characterised by hyperglycaemia, resulting from defects in insulin secretion, insulin action, or both. The chronic hyperglycaemia of diabetes is associated with long-term damage, dysfunction, and failure of various organs, especially the eyes, kidneys, nerves, heart, and blood vessels. Cardiovascular disease in general includes 4 major disease categories: coronary artery disease (CAD: MI or angina); cerebrovascular disease (stroke or TIA); peripheral vascular disease (intermittent claudication or gangrene); and aortic atherosclerosis (thoracic aortic aneurysm or AAA). Diabetes is an important risk factor for all forms of cardiovascular disease with the exception of aortic disease. This monograph will discuss CAD in greatest detail.

Renal tubular acidosis

2012-02-13

The term renal tubular acidosis (RTA) describes any one of a number of disorders, in which the excretion of fixed acid (distal RTA) or the reabsorption of filtered bicarbonate (proximal RTA) is impaired to a degree, disproportionate to any existing impairment of the glomerular filtration rate. The acid retention or bicarbonate loss results in the development of hyperchloraemic metabolic acidosis marked by hypobicarbonataemia and depressed arterial blood pH. In the absence of other acid-base disorders the serum anion gap is normal. Either hypokalaemia or hyperkalaemia may be present, depending on the nature of the acidification defect.

Erythema nodosum

2012-02-06

Erythema nodosum is a common cutaneous hypersensitivity reaction consisting of red, tender nodules over the shins, calves, and buttocks. Fever and arthralgia are often present. Lesions develop in a typical sequence. First to appear are clustered, tender patches. After a few days, lesions turn into painful nodules, often with extravasation of blood and bruises. Finally, the bruises fade and turn into pigmented, scaly macules before subsiding. Microscopy of these lesions shows septal panniculitis with inflammatory cells in the septa between subcutaneous fat lobules.

Tricuspid stenosis

2012-02-06

Tricuspid stenosis (TS) is a rare condition defined by an abnormally elevated pressure gradient across the tricuspid valve during diastolic filling of the right ventricle.

Assessment of liver dysfunction

2012-02-06

Serum liver chemistry tests, commonly called liver tests, or (mistakenly) liver function tests, are ordered for many reasons. Most laboratories offer these tests as a bundle, and this usually includes:

Acute interstitial nephritis

2012-02-06

Acute interstitial nephritis is a pattern of acute renal inflammation, usually triggered by medications, which is localised to the renal interstitium (the area between the tubules, glomeruli, and blood vessels).