Tuesday , 19 September 2017
Home » Admin (page 6)



meningitic rash

Meningitis is characterised by inflammation of the protective membranes covering the brain and spinal cord, known collectively as the meninges. The key clinical discriminator of bacterial and viral causes of meningitis is the rate of onset and severity of symptoms. Bacterial meningitis Bacterial meningitis is, classically, an acute and rapid disease process. The clinical outcome of acute bacterial meningitis is …

Read More »

Toxicity of Local Anaesthesia

Local Anaesthesia

Toxicity can be categorised as either local or systemic: Local toxicity includes: Infection Haematoma Local tissue damage e.g. intraneural injection Unwanted nerve block Necrosis through ischaemia from vasoconstrictor Pneumothorax (in blocks around the neck or axilla) Systemic toxicity: Cardiovascular toxicity includes: Cardiac depression – reduced BP, tachycardia, reduced cardiac output and acute cardiac dilatation Peripheral vasodilatation, except cocaine–vasoconstriction Respiratory toxicity includes: Medullary …

Read More »

Local Anaesthetic Types: Key Features

Local Anaesthesia Types

Lidocaine Type: Amide No inherent vasodilatation or vasoconstriction Can be used with vasoconstrictor e.g epinephrine Epinephrine is generally contraindicated in end arteries, for example in fingers, penis and earlobes. However, recent research suggests that 1:100,000 may be safe Infiltration normally 0.5-1.0% Small nerves normally 1% Large nerves normally 1.5% with epinephrine Painful on injection with no improvement with buffering, but improved …

Read More »

Compensation of Acid-base Disorders

Acid Base Balance

Compensatory mechanisms restore pH towards normal by altering pCO2 and HCO3-. Compensation of metabolic acidosis The lowered pH acts on peripheral chemoreceptors to stimulate the ventilation. Respiratory rate increases and pCO2 falls: ↓CO2 + H2O  ←  H2CO3  ←  H+ + HCO3- [H+] therefore falls, as does [HCO3-]. There is also increased reabsorption of HCO3- and increased excretion of H+from the kidneys but this is …

Read More »

Respiratory Acidosis

Respiratory Acidosis FCEM Prep

In respiratory acidosis there is raised pCO2 as the respiratory system is unable to remove enough CO2 from the body. The reaction is driven to the right, causing a rise in [H+], (i.e. a fall in pH). This inability to remove CO2 is often coupled with a failure to keep up with O2 demand. This is respiratory failure. There are two types of respiratory failure …

Read More »

Metabolic Acidosis

Metabolic Acidosis - FCEM Prep

CO2 + H2O ↔ H2CO3 ↔ H+ + HCO3-  ‘In metabolic acidosis, there is either additional acid (H+) production on the right side of the equation, or direct loss of bicarbonate which drives the equation to the right, increasing H+ and lowering pH.’ The consequent reduction in pH stimulates the respiratory centre to increase ventilation and lower pCO2. This in turn drives the reaction …

Read More »

Critical appraisal for Emergency Medicine series by Steve Goodacre: A must read before your Critical Appraisal preparation

Skill in critical appraisal has always been valued in our specialty because it is essential for the practice of evidence-based emergency medicine. The new series of six papers written by Steve Goodacre will therefore be welcomed by both trainees and trainers alike. They provide a fresh, lucid and succinct description of the important aspects of this topic with the important points reinforced by examples from emergency medicine. The section covering evaluation …

Read More »

Surrogate endpoints and Composite endpoints

When you do a randomised controlled trial, you are supposed to say up front what your endpoint is going to be. For example, if you're studying a new cholesterol-lowering drug, then good endpoints to study would be heart attack, stroke, and death. (Not-so-good endpoints to study would be level of cholesterol. This is the infamous "surrogate endpoints" where we simply …

Read More »