EDAIC Basic Sciences 4

Question 1

In a patient with renal failure, which muscle relaxant is MOST appropriate due to organ-independent elimination?

Accepted Answer

Cisatracurium

Answer

Cisatracurium undergoes Hofmann elimination (spontaneous non-enzymatic degradation at physiological pH and temperature), making it independent of renal or hepatic function.

Question 2

The cerebral metabolic rate for oxygen (CMRO2) is coupled to cerebral blood flow (CBF) through which mechanism?

Accepted Answer

Metabolic autoregulation via local vasoactive metabolites

Answer

Increased neuronal activity produces CO2, H+, K+, and adenosine, which act as local vasodilators coupling metabolic demand to blood flow.

Question 3

Propofol's mechanism of action primarily involves:

Accepted Answer

Positive allosteric modulation of GABA-A receptors

Answer

Propofol enhances inhibitory chloride currents by binding to GABA-A receptors at a site distinct from benzodiazepines, potentiating GABAergic neurotransmission.

Question 4

The pulmonary vascular resistance (PVR) is LOWEST at which lung volume?

Accepted Answer

Functional residual capacity (FRC)

Answer

At FRC, both alveolar vessels (compressed at high volumes) and extra-alveolar vessels (collapsed at low volumes) are at their optimal diameter, minimizing total PVR.

Question 5

Which coagulation pathway is assessed by the prothrombin time (PT/INR)?

Accepted Answer

Extrinsic pathway (factors VII, X, V, II, I)

Answer

PT measures the extrinsic pathway initiated by tissue factor (FIII) + FVII, then the common pathway; it is prolonged by warfarin which inhibits vitamin K-dependent factors II, VII, IX, X.

EDAIC - European Diploma in Anesthesiology and Intensive Care Practice Test

EDAIC - European Diploma in Anesthesiology and Intensive Care Practice Test

EDAIC Basic Sciences 4