Fatigue / stress fracture

It is a fracture that occurs not because of a single violent injury but results from repeated stress. It is commonly seen in athletes and new military or police force recruits.

The pathology here is that the rate of microdamage from repeated stress exceeds the rate of repair. Thus there is accumulation of these microdamages and there is eventually a complete fracture across the full width of the bones.

Majority of stress fractures occurs in the bones of the lower limbs, notably the metatarsals. Other sites may be the shaft of the tibia or the neck of femur.

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Hypokalemia - Potassium replacement calculation

DEFINITION Hypokalemia is defined as a serum potassium level of less than 3.5 mmol/L. Normal level= 3.5-5.5 mmol/L. It is encountered in >20% of patients. Patients are usually asymptomatic but severe arrhythmias and rhabdomyolysis can occur. Non-specific complaints include easy fatiguability and skeletal muscle weakness. The preferred method of replacement is via the oral route but at times this is not possible. The article below will give you an idea about how to calculate the amount of KCl to be given I.V. 1) Potassium deficit in mmol is calculated as given below: K deficit (mmol) = (K normal lower limit - K measured ) x kg body weight x 0.4 2) Daily potassium requirement is around 1 mmol/Kg body weight. 3) 13.4 mmol of potassium found in 1 g KCl . ( molecular weight KCl = 39.1 + 35.5 = 74.6) Suppose we get an asymptomatic patient of 70 Kg with a serum potassium level of 3.0 mmol/L and he is on nil by mouth but having...

Endomysium, Perimysium and epimysium - definition, histology

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The plantar reflex - Babinski's sign

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Gram staining - Procedure, mechanism, explanation

INTRODUCTION The Gram stain was developed in 1884 by the Danish bacteriologist Hans Christian Gram. It is one of the most useful staining procedures because it classifies bacteria into two large groups: 1) gram-positive and 2) gram-negative. PROCEDURE 1) A heat-fixed smear is flooded with a basic purple dye, usually crystal violet. Because the purple stain imparts its color to all cells, it is referred to as a primary stain . 2) After 1 minute, the crystal violet is drained off and washed with distilled water. The smear is then covered with Gram's iodine, a mordant or helper . When the iodine is washed off, both gram-positive and gram-negative bacteria appear dark violet or purple. 3) Next, the slide is washed with alcohol (95% ethanol) or an alcohol-acetone solution. This solution is a decolorizing agent which removes the purple from the cells of some species but not from others. When the procedure is carried out, the slide is held ...

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