283 Pathophysiology | Chamberlain
1. A patient with emphysema presents with pursed-lip breathing and a barrel chest. What is
the primary underlying pathophysiology?
A. Excessive mucus production in the bronchi
B. Destruction of alveolar walls and loss of elastic recoil
C. Permanent dilation of the bronchioles
D. Hyper-responsiveness of the airway to allergens
Correct Answer: B
Expert Explanation: Emphysema involves the destruction of alveolar walls, which
decreases the surface area available for gas exchange. The loss of elastic recoil leads to air
trapping, which clinically manifests as a barrel chest. Pursed-lip breathing is a
compensatory mechanism used to maintain airway pressure and prevent collapse during
expiration.
2. Which clinical manifestation is most characteristic of right-sided heart failure?
A. Pulmonary edema and crackles
B. Orthopnea and paroxysmal nocturnal dyspnea
C. Peripheral edema and jugular venous distention
D. Pink frothy sputum and cough
,Correct Answer: C
Expert Explanation: Right-sided heart failure causes blood to back up into the systemic
venous circulation because the right ventricle cannot pump effectively. This leads to
increased hydrostatic pressure in the systemic veins, causing peripheral edema and jugular
venous distention. In contrast, pulmonary symptoms like crackles and orthopnea are
hallmark signs of left-sided heart failure.
3. A patient is in the oliguric phase of acute kidney injury (AKI). Which electrolyte imbalance
is the priority concern?
A. Hyperkalemia
B. Hypokalemia
C. Hypomagnesemia
D. Hypercalcemia
Correct Answer: A
Expert Explanation: During the oliguric phase of AKI, the kidneys are unable to excrete
potassium effectively, leading to hyperkalemia. Hyperkalemia is a medical emergency
because it can cause lethal cardiac dysrhythmias. Monitoring the ECG for peaked T waves
and wide QRS complexes is a critical nursing intervention in this stage.
4. What is the primary compensatory mechanism for a patient in metabolic acidosis?
A. Hypoventilation to retain CO2
B. Increased renal excretion of bicarbonate
, C. Kussmaul respirations to blow off CO2
D. Decreased heart rate to reduce metabolic demand
Correct Answer: C
Expert Explanation: In metabolic acidosis, the body attempts to compensate by inducing a
state of respiratory alkalosis. Kussmaul respirations are deep, rapid breaths designed to
eliminate carbon dioxide, which reduces the amount of carbonic acid in the blood. This
respiratory response begins within minutes of the onset of the metabolic imbalance.
5. Which biomarker is most specific for diagnosing an acute myocardial infarction (MI)?
A. Troponin I
B. Myoglobin
C. Creatine Kinase (CK-MB)
D. C-reactive protein
Correct Answer: A
Expert Explanation: Troponin I is highly specific to cardiac muscle tissue and is released
into the bloodstream when myocardial cells are damaged. It remains elevated for several
days, making it useful for both acute and slightly delayed diagnosis. While CK-MB is also
used, it is less specific than Troponin I for cardiac injury.