UM Medex posttest 2025

1. 1. Diastolic phase of the cardiac cycle can be divided into a few stages.

2. Which stage contributes to the least volume of blood into the ventricle?

• Isovolumetric ventricular relaxation.

• Rapid ventricular filling.

• Slow ventricular filling.

• Atrial contraction.

2. 2. Which of the following ECG findings is consistent with left atrial enlargement?

• Increased P-wave amplitude

• Increased P-wave duration

• Increased P-wave amplitude and duration

• Terminal P negativity in lead I

3. 3. Which point on the pressure-volume loop below corresponds to the peak of the R wave on the ECG?

• A

• B

• C

• D

4. 4. A 44-year-old woman is undergoing free flap surgery for breast reconstruction. The

   surgeons are concerned about microvascular perfusion in the donor tissue. The

   blood pressure decreases to 85/44mmHg.

   What is the most important variable to consider in order to optimise flap perfusion according to Hagen–Poiseuille equation?

• Blood pressure

• Heart rate

• Blood viscosity

• Vessel calibre

5. 5. A 67-year-old man has a laryngectomy and neck dissection for laryngeal cancer. At the end of the operation, the surgeon asks you to perform a Valsalva manoeuvre in order to look for bleeding points.

Which of the following changes does not occur with a Valsalva manoeuvre in a healthy patient?

• Decrease in blood pressure in phase 1.

• Bradycardia in phase 1.

• Baroreceptor activation in phase 2.

• Reflex bradycardia in phase 4.

6. 6. During the spirometry test, the physician plans to identify the maximal volume of gas that can be expelled after maximal inspiration.

   1. What is the type of lung volume that best describes the above explanation?

• Total lung capacity.

• Functional residual capacity.

• Inspiratory reserve volume.

• Vital capacity.

7. 7. A 29 y.o. obstetric patient is pre-oxygenated before general anaesthesia for EMLSCS.

   Which physiological factors are likely to leave obstetric patients prone to desaturations?

• Increased cardiac output.

• Increased lung compliance.

• Decreased functional residual capacity.

• Decreased haemoglobin level.

8. 8. Hypoxic pulmonary vasoconstriction (HPV) in the lungs is a compensatory

   mechanism to improve ventilation-perfusion matching. In which of the following

   would a decrease most likely trigger HPV?

• Partial pressure of oxygen in the pulmonary artery.

• Partial pressure of oxygen in the pulmonary veins.

• Partial pressure of oxygen in the alveoli.

• Oxygen saturation of hemoglobin in the pulmonary artery.

9. 9. You are inducing a child for toilet training and suturing a laceration wound on the forehead

   via inhalation induction. Which of the following speeds up the induction of

   anaesthesia with volatile anaesthetics?

• Use of nitric oxide

• Increased cardiac output

• Agents with a high blood/gas solubility coefficient

• Increased alveolar ventilation

10. 10. The oxygen dissociation curve is a sigmoid-shaped curve that describes the percentage of oxygen saturation in hemoglobin (Hb) at different partial pressures of oxygen. One of the important points is the ICU point.

    1. What is the best value of PaO2 at this point?

• 100 mmHg.

• 90 mmHg.

• 80 mmHg.

• 60 mmHg.