PH
Which pH value is within the normal range?
A. 7.12
B. 7.28
C. 7.40
D. 7.52
Answer: C. 7.40
Rationale: Normal blood pH is typically 7.35–7.45.
Which PaCO₂ value is within the normal range?
A. 28 mmHg
B. 34 mmHg
C. 40 mmHg
D. 52 mmHg
Answer: C. 40 mmHg
Rationale: Normal PaCO₂ levels are typically 35–45 mmHg.
Which PaO₂ value is within the normal range?
A. 58 mmHg
B. 72 mmHg
C. 95 mmHg
D. 110 mmHg
Answer: C. 95 mmHg
Rationale: Normal PaO₂ levels are typically 80–100 mmHg.
Which HCO₃⁻ value is within the normal range?
A. 18 mEq/L
B. 22 mEq/L
C. 30 mEq/L
D. 35 mEq/L
Answer: B. 22 mEq/L
Rationale: Normal bicarbonate (HCO₃⁻) levels are typically 22–26 mEq/L.
A nurse is assessing four clients. Which blood pressure reading requires the most immediate intervention?
A. 118/76 mmHg in a 22-year-old athlete
B. 136/84 mmHg in an anxious client reporting pain
C. 88/50 mmHg in a postoperative client with dizziness
D. 142/88 mmHg in a client with chronic hypertension
Answer: C. 88/50 mmHg in a postoperative client with dizziness
Rationale: Hypotension with dizziness after surgery may indicate bleeding, hypovolemia, or shock and requires immediate assessment.
A pH of 7.30 indicates:
A. Normal acid-base balance
B. Acidosis
C. Alkalosis
D. Hypernatremia
Answer: B. Acidosis
Rationale: A pH below 7.35 indicates acidosis.
A PaCO₂ level of 50 mmHg indicates:
A. Respiratory alkalosis
B. Normal ventilation
C. Respiratory acidosis
D. Metabolic alkalosis
Answer: C. Respiratory acidosis
Rationale: A PaCO₂ above 45 mmHg means excess carbon dioxide is retained, leading to respiratory acidosis.
A PaO₂ level of 68 mmHg indicates:
A. Normal oxygenation
B. Hyperventilation
C. Hypoxemia
D. Respiratory alkalosis
Answer: C. Hypoxemia
Rationale: A PaO₂ below 80 mmHg suggests low oxygen levels in the blood (hypoxemia).
An HCO₃⁻ level of 18 mEq/L indicates:
A. Metabolic alkalosis
B. Normal acid-base balance
C. Metabolic acidosis
D. Respiratory acidosis
Answer: C. Metabolic acidosis
Rationale: A bicarbonate level below 22 mEq/L suggests metabolic acidosis.
A client’s heart rate changes from 84 beats/min to 132 beats/min after surgery. Which assessment finding is most concerning?
A. The client reports incisional pain rated 4/10
B. The client’s urine output is 15 mL/hr
C. The client requests water frequently
D. The client is sleepy after receiving pain medication
Answer: B. The client’s urine output is 15 mL/hr
Rationale: Tachycardia with low urine output may indicate poor perfusion, hypovolemia, or shock.
Which pH value should the nurse identify as alkalosis?
A. 7.18
B. 7.32
C. 7.46
D. 7.35
Answer: C. 7.46
Rationale: A pH above 7.45 indicates alkalosis.
Which PaCO₂ value should the nurse identify as respiratory alkalosis?
A. 30 mmHg
B. 38 mmHg
C. 42 mmHg
D. 45 mmHg
Answer: A. 30 mmHg
Rationale: A PaCO₂ below 35 mmHg indicates respiratory alkalosis, often caused by hyperventilation.
Which PaO₂ value should the nurse identify as severely low?
A. 92 mmHg
B. 85 mmHg
C. 76 mmHg
D. 50 mmHg
Answer: D. 50 mmHg
Rationale: A PaO₂ of 50 mmHg is critically low and indicates significant hypoxemia.
Which HCO₃⁻ value should the nurse identify as metabolic alkalosis?
A. 20 mEq/L
B. 24 mEq/L
C. 28 mEq/L
D. 22 mEq/L
Answer: C. 28 mEq/L
Rationale: An HCO₃⁻ level above 26 mEq/L indicates metabolic alkalosis
Which respiratory assessment finding should the nurse recognize as an early sign of respiratory deterioration?
A. Respiratory rate of 10 breaths/min while sleeping
B. Oxygen saturation of 96% on room air
C. Restlessness and respirations of 28 breaths/min
D. Occasional dry cough after ambulation
Answer: C. Restlessness and respirations of 28 breaths/min
Rationale: Tachypnea and restlessness are often early signs of hypoxia and respiratory distress.
Which pH level is considered the lowest normal result?
A. 7.20
B. 7.35
C. 7.45
D. 7.60
Answer: B. 7.35
Rationale: The lower limit of normal blood pH is 7.35.
Which PaCO₂ level is considered the highest normal result?
A. 25 mmHg
B. 35 mmHg
C. 45 mmHg
D. 55 mmHg
Answer: C. 45 mmHg
Rationale: The upper limit of normal PaCO₂ is 45 mmHg.
Which PaO₂ level is considered the lowest normal result?
A. 60 mmHg
B. 70 mmHg
C. 80 mmHg
D. 100 mmHg
Answer: C. 80 mmHg
Rationale: The lower limit of normal PaO₂ is approximately 80 mmHg.
Which HCO₃⁻ level is considered the highest normal result?
A. 18 mEq/L
B. 22 mEq/L
C. 26 mEq/L
D. 32 mEq/L
Answer: C. 26 mEq/L
Rationale: The upper limit of normal bicarbonate is 26 mEq/L.
A client with COPD has an oxygen saturation of 89% on room air. Which action should the nurse take first?
A. Apply a nonrebreather mask at 15 L/min
B. Document the finding as expected
C. Encourage coughing and deep breathing only
D. Assess the client’s baseline oxygen saturation level
Answer: D. Assess the client’s baseline oxygen saturation level
Rationale: Many clients with COPD normally maintain lower oxygen saturations. The nurse should assess baseline status before intervening aggressively.
A severely abnormal pH can affect which body system most critically?
A. Nervous and cardiovascular systems
B. Hair and nails
C. Vision only
D. Digestive enzymes only
Answer: A. Nervous and cardiovascular systems
Rationale: Significant acid-base imbalances can impair brain function, heart rhythm, and overall cellular function.
PaCO₂ levels primarily reflect how effectively the body is:
A. Digesting nutrients
B. Ventilating carbon dioxide
C. Producing insulin
D. Filtering blood through the kidneys
Answer: B. Ventilating carbon dioxide
Rationale: PaCO₂ measures the amount of carbon dioxide in arterial blood and reflects respiratory ventilation status.
PaO₂ primarily measures:
A. Carbon dioxide levels in the blood
B. Oxygen levels in arterial blood
C. Kidney filtration ability
D. Blood glucose concentration
Answer: B. Oxygen levels in arterial blood
Rationale: PaO₂ reflects the amount of oxygen dissolved in arterial blood and helps assess oxygenation status.
HCO₃⁻ is primarily regulated by which organ system?
A. Respiratory system
B. Nervous system
C. Renal system
D. Integumentary system
Answer: C. Renal system
Rationale: The kidneys regulate bicarbonate levels to help maintain acid-base balance in the body.
A nurse cares for a client with a temperature of 102.6°F (39.2°C), heart rate 124 beats/min, and confusion. Which finding is most concerning?
A. Fever above normal range
B. Tachycardia related to fever
C. Confusion accompanying hyperthermia
D. Increased metabolic demand
Answer: C. Confusion accompanying hyperthermia
Rationale: Altered mental status with high fever may indicate severe infection, sepsis, or neurologic compromise and requires rapid intervention.