Calculations

Question 1

Positive and Negative Predictive Values

(using specificity, sensitivity, prevalence)

Answer 1

Question 2

Normal Reference Range Intervals for Blood Gas Analysis

Answer 2

• pH = 7.35-7.45;
• PO2 is variable in venous blood;
• PCO2 = 40 mmHg,
• HCO3 = 24-30 mEq/L,
• iCa++ = 1.4-1.8 mmol/L.

This is a general range, with each species having slight changes to this range

Question 3

You have a 6-kg cat that you wish to raise his PCV from 15 to 25%. You plan to administer packed red blood cells. How many milliliters of packed red blood cells will this cat need?

Answer 3

60 mL

• In order to raise the PCV 1% you will need to give 1ml/kg of packed red blood cells. So it takes 6mls to raise this cat’s PCV by 1%. If we are going to increase it by 10% we will need 60ml of packed red blood cells

Question 4

Reading a Balance Sheet:

Calculating Assets?

Answer 4

• Assets = Liabilities + Shareholder’s Equity
• Here, Total Liabilities = $80,000 and Equity = $50,000. Therefore, the liabilities + equities = $130,000.

Question 5

Calculating RER

(resting energy requirement)

Answer 5

body weight (kg) to the 0.75 power times 70.

(70 * BW^0.75)

Another formula that has been recommended for this calculation is (30 * BW + 70). Note that the results will be different compared to the (70 * BW^0.75) formula but they both should get you close enough to the correct answer.

Question 6

Cerebral Perfusion Pressure

(Cushing’s Reflex)

Answer 6

Cerebral perfusion pressure= Mean arterial pressure - intracranial pressure

or

(CPP=MAP-ICP).

This response is seen in situations where intracranial pressure increases such as in brain trauma. In this case, you need to think before you intervene to decrease your patient’s mean arterial pressure as this might eliminate cerebral blood flow and kill your patient.