*(&
Case Study Discussions
CHAPTER 1
DISCUSSION OF CASE STUDY 1.1
The result is most likely to be a transcription error (a ‘blunder’) since the result
obtained is not compatible with life. Perhaps the true result was 3.5mmol
dm–3 and not 35mmol dm–3. In any case, a second K+ determination is
required.
DISCUSSION OF CASE STUDY 1.2
Sensitivity = (95/95 + 5) q 100 = 95%
Specificity = (95/95 + 5) q 100 = 95%
This means that the test will be positive in 95% of patients with prostate
cancer and negative in 95% of people without the disease. That is, 5% of
people with prostate cancer will be missed. An ideal diagnostic test will have
100% sensitivity and specificity but this is rarely achieved.
CHAPTER 2
DISCUSSION OF CASE STUDY 2.1
Brian is most likely in the early stages of a malarial infection. The disease
is caused by several species of Plasmodium. This could be confirmed by a
microscopic examination of a blood smear to show the presence of the
parasite. Brian had traveled to an area where malaria is endemic and he
should have taken appropriate prophylatic drugs.
CHAPTER 3
DISCUSSION OF CASE STUDY 3.1
The infection probably began as folliculitis that became inflamed and
developed into an abscess. The most likely cause consistent with the
appearances of the cultured microorganism is Staphylococcus aureus.
The formation of an abscess restricts the flow of blood to the center of
the infection, reducing the effectiveness of antibiotics, hence the need for
excision and drainage.