EDAIC - European Diploma in Anesthesiology and Intensive Care Clinical Measurement and Physics Questions and Answers

Question 1

A patient's invasive arterial blood pressure waveform displays a high systolic peak with a narrow anacrotic limb and several oscillations following the dicrotic notch.
The mean arterial pressure is likely accurate.
Which of the following best describes this phenomenon and its most common cause?

Accepted Answer

Underdamping, caused by excessive tubing length or stiff tubing.

Answer

Overdamping, caused by an air bubble in the tubing.

Answer

Signal aliasing, caused by a low sampling rate of the monitor.

Answer

Electromagnetic interference, caused by the use of surgical diathermy.

Question 2

According to Poiseuille's law for laminar flow, which of the following modifications to a standard intravenous cannula setup would result in the greatest increase in flow rate for a given infusion pressure?

Accepted Answer

Increasing the internal radius of the cannula by 50%.

Answer

Doubling the length of the infusion tubing.

Answer

Halving the viscosity of the infused fluid (e.g., using crystalloid instead of blood).

Answer

Doubling the height of the IV bag above the patient.

Question 3

Which physical principle is utilized for the specific measurement of oxygen concentration in the fresh gas flow by most modern anesthetic machines?

Accepted Answer

Paramagnetism

Answer

Infrared absorption spectrometry

Answer

Raman scattering

Answer

Electrochemical reaction (galvanic cell)

Question 4

A patient rescued from a house fire is brought to the emergency department. They are tachypneic and confused. A standard pulse oximeter shows a saturation (SpO2) of 98%, but an arterial blood gas analysis reveals a fractional oxyhemoglobin (SaO2) of 80% and a PaO2 of 95 mmHg. What is the most likely explanation for this discrepancy?

Accepted Answer

The presence of carboxyhemoglobin.

Answer

The presence of methemoglobinemia.

Answer

Severe peripheral vasoconstriction.

Answer

Interference from intravenous methylene blue dye.

Question 5

The output of a modern variable-bypass anesthetic vaporizer remains constant across a range of ambient temperatures. This is achieved through a mechanism that alters the 'splitting ratio' of fresh gas flow. What is the underlying physical principle that necessitates this temperature compensation?

Accepted Answer

The saturated vapor pressure of the anesthetic agent is directly proportional to temperature.

Answer

The viscosity of the anesthetic vapor decreases as temperature increases.

Answer

The density of the fresh gas flow changes with temperature according to Charles's Law.

Answer

The solubility of the anesthetic agent in blood is inversely proportional to temperature.

Question 6

During a procedure on a patient with a central venous catheter and an external pacemaker, which of the following is the most critical safety measure for preventing microshock?

Accepted Answer

Confirming proper grounding (earthing) of all electrical equipment connected to the patient.

Answer

Using a line isolation monitor in the operating room.

Answer

Ensuring the patient is placed on a non-conductive operating table.

Answer

Wearing insulated gloves when handling electrical equipment.