Pathophysiology

Question 1

What is the lethal triad of trauma?

Answer 1

Consists of hypothermia, acidosis and coagulopathy. Factors that increase risk of mortality in patients experiencing trauma

Question 2

Describe the patho of TBI

Answer 2

Mechanical tissue destruction causes cell death and cerebral oedema. Oedema increases intracranial pressure. Vasoregulation is then impaired and reduces cerebral blood flow despite adequate MAP.

Question 3

What is the pathophysiology of croup?

Answer 3

Infection enters the upper airways resulting in immune response. Response triggers oedema, increased mucous production resulting in narrowing of the upper airways.

Question 4

How does asthma result in a loss of cardiac output?

Answer 4

Gas trapping occurs due to bronchoconstriction as air unable to adequately escape lungs. This increases intrapulmonary pressure. as this increases it can place pressure on the inferior vena cava reducing blood flow into the heart. As venous return to the heart reduces, so does the stroke volume and this results in a reduction and eventual loss of cardiac output.

Question 5

What is the patho of an ischaemic stroke?

Answer 5

Atherosclerosis and plaque rupture results in a clot formation. Clot formation narrows the lumen of cerebral blood vessels resulting in reduced blood flow. Oxygen and glucose supply is reduced and inhibits aerobic metabolism at the cells causing necrosis and apoptosis.

Question 6

What is adrenal insufficiency?

Answer 6

Endocrine disorder characterised by inadequate production of cortisol +/- aldosterone leading to impaired regulation of glucose levels and cardiovascular function

Question 7

What is the patho of diabetic ketoacidosis?

Answer 7

Excess unregulated glucose levels in the bloodstream occur due to lack of insulin production. Body uses triglycerides and amino acids as alternative energy source. This forms acidic ketone bodies and results in metabolic acidosis.

Question 8

What is the patho of autonomic dysreflexia?

Answer 8

Noxious stimulation below the level of spinal cord injury (T6 or above) causes a reflex sympathetic response resulting in vasoconstriction and increased blood pressure. The negative feedback loop is interrupted and parasympathetic input unable to regulate blood pressure from above the injury. Results in uncontrolled hypertension.

Question 9

What is the process of atherosclerosis?

Answer 9

1. Fatty streaks develop within the lumen of arteries - consists on smooth muscle, cholesterol and macrophages
2. Fibrous plaque develops over the streaks caused by migration of macrophages and lymphocytes
3. If fibrous cap ruptures due to turbulent blood flow, the cholesterol and connective tissue of the wall is exposed and this result sin an immune response and clot formation at the site. This can partially or completely block blood flow through the artery

Question 10

What is the patho of emphysema?

Answer 10

White blood cells gather in alveoli resulting in breakdown of elastic fibres, thickening of bronchial walls and loss of pulmonary tissue

Question 11

What is the patho of chronic bronchitis?

Answer 11

Constant inflammation increases size and number of goblet cells within the small and large airways. Smoke or other toxin damage also results in reduced number of cilia and therefore an inability to clear mucus. This causes reduced ventilation and a V/Q mismatch