A. Louise Fincher

Effect of Diathermy on Muscle Temperature, Electromyography, and Mechanomyography

This study examined the effects of pulsed shortwave diathermy on intramuscular temperature, surface electromyography (EMG), and mechanomyography (MMG) of the vastus lateralis. Thirty‐five men were assigned to diathermy (n = 13), sham‐diathermy (n = 12), or control (n = 10) groups. Each subject performed isometric maximal voluntary contractions (MVCs) and incremental ramp contractions (10%–90% MVC) before and after treatment. Torque, intramuscular temperature, EMG, and MMG were recorded. Temperature for the diathermy group increased (P ≤ 0.05). MMG amplitude and instantaneous mean frequency (IMF) increased (P ≤ 0.05) during the MVCs with the greatest increases observed for the diathermy group. During ramp contractions, MMG amplitude and IMF increased at all percentages of MVC (10%–90%) for the diathermy group only (P ≤ 0.05). There were no changes in MVC torque, EMG amplitude, or IMF. Diathermy treatments may decrease musculotendinous stiffness, but not absolute strength or motor control strategies that influence force production. Muscle Nerve, 2008

Managing Diabetic Emergencies

Acute hypoglycaemia Hypoglycaemia is the most common complication of diabetes, accounting for around 90,000 ambulance call outs and 8,000 hospital admissions per year in the UK. Symptoms generally present at blood glucose levels of 2.5–3mmol/L but they also manifest outside this range and patients can report different symptoms. Patients should be told that any capillary blood glucose (CBG) less than 4mmol/L requires treatment — “four is the floor”. Symptoms consist of anxiety, palpitations, tremor and sweating (adrenergic symptoms, sometimes called warning symptoms), irritability, incoordination, confusion, weakness, fatigue and seizures (neuroglycopaenic manifestations) and, later, loss of consciousness. Hypoglycaemia can occur in both type 1 and type 2 diabetes. It is most commonly seen in patients treated with insulin or drugs that affect the activity of insulin (ie, insulinotropic drugs), such as sulphonylureas, or both. Long-acting sulphonylureas (glibenclamide and chlorpropamide) are more likely to cause hypoglycaemia. These are renally excreted so should be avoided in those with impaired renal function — drug accumulation increases risk of hypoglycaemia — and in elderly patients (who are likely to have some renal impairment). Panel 1 describes diabetes treatments and their risk of hypoglycaemia. Hypoglycaemic events can also be a consequence of efforts to tighten glycaemic control and a balance is needed. Non-antidiabetic agents that have been implicated in hypoglycaemia include quinine, quinolone antibiotics, pentamidine and co-trimoxazole — they may be insulinotropic. Alcohol can precipitate hypoglycaemia by inhibiting gluconeogenesis. Conditions that can precipitate hypoglycaemia, either on their own or in combination with diabetes drugs, are endstage liver disease, renal failure, starvation, infection and adrenal insufficiency. Insulinoma is an uncommon cancer that can cause fasting hypoglycaemia. This is normally managed surgically but treatment with diazoxide can help to reduce hypoglycaemic episodes. Hypoglycaemia is rated as mild, moderate or severe as follows: