Miscellaneous

Question 1

What are specific tests good for?

Answer 1

When positive, help rule IN disease

The specificity of a sign is the proportion of people without the disease who do not have the sign (‘negative in health’). For example, an 80% specificity means that 8 out of 10 people without that sign do not have the condition.

Question 2

What are sensitive tests good for?

Answer 2

When negative help rule OUT disease

The sensitivity of a sign is the proportion of people with the disease who have the sign - that is, those who are correctly identified by the test (‘positive in disease’). A sensitivity of 80% means that assessment of the presence of that sign will pick up 80% of people with the condition (but will not pick up 20%).

Question 3

Type I Respiratory Failure

Answer 3

Impaired **gas exchange **leading to hypoxaemia

PaO2 < 60mmHg

Question 4

Type II Respiratory Failure

Answer 4

Hypoventilation resulting in hypercapnia

PaCO2 > 50mmHg