Miami Dade College
2 MAXE · 2CDM
★ ★
MDC Medical Campus — School of Nursing
EST. 1960
THE COLLEGE OF THE AMERICAN DREAM.
MDC2 — Examination 2
A B G I N T E R P R E TAT I O N · AC I D - B A S E · G I D I S O R D E RS · LO W E R G I · PA R E N T E RA L
NUTRITION
INSTITUTION Miami Dade College COURSE CODE MDC2
PROGRAM Associate of Science in Nursing — ACADEMIC YEAR
ADN
EXAM TITLE MDC2 Examination 2 — ABGs, GI, COURSE TITLE Med-Surg Nursing II
Lower GI
TOTAL QUESTIONS 75 Questions FORMAT Multiple Choice — Select the
Single Best Answer
EXAMINATION INSTRUCTIONS
▸ Select the single best answer for each multiple-choice question unless otherwise instructed.
▸ Content covers ABG interpretation, acid-base imbalances, upper and lower GI disorders, IBD, colorectal
cancer, GI bleeding, parenteral nutrition, and stoma care.
▸ Normal ABG reference values: pH 7.35–7.45, PaCO₂ 35–45 mm Hg, HCO₃⁻ 22–26 mEq/L.
▸ Correct answers and clinical rationales appear below each question for board review purposes.
, COMPREHENSIVE EXAMINATION Questions 1 – 75
1. A 65-year-old male with a history of COPD presents with confusion and lethargy. ABG
results: pH 7.30, PaCO₂ 58 mmHg, HCO₃⁻ 26 mEq/L. What is the acid-base imbalance?
A. Fully compensated respiratory acidosis
B. Uncompensated respiratory acidosis
C. Partially compensated metabolic acidosis
D. Mixed respiratory and metabolic acidosis
CORRECT ANSWER B — Uncompensated respiratory acidosis.
RATIONALE pH 7.30 = acidosis (<7.35). PaCO₂ 58 = elevated (>45) — respiratory cause. HCO₃⁻ 26
= normal (22–26). pH and only one other value (PaCO₂) are abnormal while HCO₃⁻
is normal = uncompensated. The kidneys have not yet begun retaining
bicarbonate. This is an acute COPD exacerbation — the patient is retaining CO₂
from hypoventilation.
2. A 22-year-old woman is hyperventilating from anxiety. ABG: pH 7.49, PaCO₂ 30 mmHg,
HCO₃⁻ 22 mEq/L. What is the acid-base imbalance?
A. Uncompensated respiratory alkalosis
B. Partially compensated respiratory alkalosis
C. Fully compensated metabolic alkalosis
D. Uncompensated metabolic acidosis
CORRECT ANSWER A — Uncompensated respiratory alkalosis.
RATIONALE pH 7.49 = alkalosis (>7.45). PaCO₂ 30 = low (<35) — respiratory cause from
hyperventilation. HCO₃⁻ 22 = normal. pH and only PaCO₂ are abnormal =
uncompensated. The kidneys have not yet begun excreting bicarbonate. Anxiety
is a common cause of acute respiratory alkalosis — treatment focuses on calming
the patient and addressing the underlying anxiety.
,3. A patient with diabetic ketoacidosis has ABG: pH 7.28, PaCO₂ 32 mmHg, HCO₃⁻ 16 mEq/L.
What is the acid-base imbalance?
A. Uncompensated metabolic acidosis
B. Partially compensated metabolic acidosis
C. Fully compensated respiratory acidosis
D. Mixed metabolic and respiratory alkalosis
CORRECT ANSWER B — Partially compensated metabolic acidosis.
RATIONALE pH 7.28 = acidosis. HCO₃⁻ 16 = low — primary metabolic acidosis. PaCO₂ 32 = low
(<35) — the lungs are hyperventilating (Kussmaul respirations) to compensate by
blowing off CO₂. ALL THREE values are abnormal, but pH is still not normal =
partially compensated. The lungs are attempting to correct a metabolic problem,
but compensation is incomplete.
4. A 55-year-old woman with prolonged vomiting has ABG: pH 7.47, PaCO₂ 48 mmHg, HCO₃⁻
30 mEq/L. What is the acid-base imbalance?
A. Uncompensated metabolic alkalosis
B. Partially compensated metabolic alkalosis
C. Fully compensated respiratory acidosis
D. Uncompensated respiratory alkalosis
CORRECT ANSWER B — Partially compensated metabolic alkalosis.
RATIONALE pH 7.47 = alkalosis. HCO₃⁻ 30 = elevated — primary metabolic alkalosis (loss of
gastric HCl from vomiting). PaCO₂ 48 = elevated — compensatory hypoventilation
(retaining CO₂/acid). ALL THREE values are abnormal, but pH is still not normal =
partially compensated. The lungs are attempting to correct a metabolic alkalosis
by retaining CO₂, but haven't fully normalized pH yet.
, 5. A patient's ABG: pH 7.36, PaCO₂ 50 mmHg, HCO₃⁻ 30 mEq/L. What is the acid-base
imbalance?
A. Uncompensated respiratory acidosis
B. Partially compensated metabolic alkalosis
C. Fully compensated respiratory acidosis
D. Fully compensated metabolic alkalosis
CORRECT ANSWER C — Fully compensated respiratory acidosis.
RATIONALE pH 7.36 = normal (barely acidic side). PaCO₂ 50 = elevated — primary respiratory
acidosis. HCO₃⁻ 30 = elevated — renal compensation (retaining base). pH is normal
while BOTH other values are abnormal = fully compensated. This is typical of
chronic COPD — the kidneys have fully compensated for chronic CO₂ retention by
retaining bicarbonate over days to weeks.
6. A patient with sepsis presents with ABG: pH 7.10, PaCO₂ 55 mmHg, HCO₃⁻ 15 mEq/L. What
acid-base imbalance is most likely?
A. Uncompensated respiratory acidosis only
B. Mixed respiratory and metabolic acidosis
C. Partially compensated metabolic alkalosis
D. Fully compensated respiratory alkalosis
CORRECT ANSWER B — Mixed respiratory and metabolic acidosis.
RATIONALE pH 7.10 is severely acidotic. BOTH PaCO₂ is elevated (respiratory acidosis —
hypoventilation or impaired gas exchange from sepsis) AND HCO₃⁻ is low
(metabolic acidosis — lactic acidosis from sepsis-induced hypoperfusion). When
both components drive pH in the same direction beyond what simple
compensation would allow, it is a MIXED disorder. Sepsis commonly causes mixed
acidosis: lactic acid (metabolic) + hypoperfusion/respiratory failure (respiratory).
2 MAXE · 2CDM
★ ★
MDC Medical Campus — School of Nursing
EST. 1960
THE COLLEGE OF THE AMERICAN DREAM.
MDC2 — Examination 2
A B G I N T E R P R E TAT I O N · AC I D - B A S E · G I D I S O R D E RS · LO W E R G I · PA R E N T E RA L
NUTRITION
INSTITUTION Miami Dade College COURSE CODE MDC2
PROGRAM Associate of Science in Nursing — ACADEMIC YEAR
ADN
EXAM TITLE MDC2 Examination 2 — ABGs, GI, COURSE TITLE Med-Surg Nursing II
Lower GI
TOTAL QUESTIONS 75 Questions FORMAT Multiple Choice — Select the
Single Best Answer
EXAMINATION INSTRUCTIONS
▸ Select the single best answer for each multiple-choice question unless otherwise instructed.
▸ Content covers ABG interpretation, acid-base imbalances, upper and lower GI disorders, IBD, colorectal
cancer, GI bleeding, parenteral nutrition, and stoma care.
▸ Normal ABG reference values: pH 7.35–7.45, PaCO₂ 35–45 mm Hg, HCO₃⁻ 22–26 mEq/L.
▸ Correct answers and clinical rationales appear below each question for board review purposes.
, COMPREHENSIVE EXAMINATION Questions 1 – 75
1. A 65-year-old male with a history of COPD presents with confusion and lethargy. ABG
results: pH 7.30, PaCO₂ 58 mmHg, HCO₃⁻ 26 mEq/L. What is the acid-base imbalance?
A. Fully compensated respiratory acidosis
B. Uncompensated respiratory acidosis
C. Partially compensated metabolic acidosis
D. Mixed respiratory and metabolic acidosis
CORRECT ANSWER B — Uncompensated respiratory acidosis.
RATIONALE pH 7.30 = acidosis (<7.35). PaCO₂ 58 = elevated (>45) — respiratory cause. HCO₃⁻ 26
= normal (22–26). pH and only one other value (PaCO₂) are abnormal while HCO₃⁻
is normal = uncompensated. The kidneys have not yet begun retaining
bicarbonate. This is an acute COPD exacerbation — the patient is retaining CO₂
from hypoventilation.
2. A 22-year-old woman is hyperventilating from anxiety. ABG: pH 7.49, PaCO₂ 30 mmHg,
HCO₃⁻ 22 mEq/L. What is the acid-base imbalance?
A. Uncompensated respiratory alkalosis
B. Partially compensated respiratory alkalosis
C. Fully compensated metabolic alkalosis
D. Uncompensated metabolic acidosis
CORRECT ANSWER A — Uncompensated respiratory alkalosis.
RATIONALE pH 7.49 = alkalosis (>7.45). PaCO₂ 30 = low (<35) — respiratory cause from
hyperventilation. HCO₃⁻ 22 = normal. pH and only PaCO₂ are abnormal =
uncompensated. The kidneys have not yet begun excreting bicarbonate. Anxiety
is a common cause of acute respiratory alkalosis — treatment focuses on calming
the patient and addressing the underlying anxiety.
,3. A patient with diabetic ketoacidosis has ABG: pH 7.28, PaCO₂ 32 mmHg, HCO₃⁻ 16 mEq/L.
What is the acid-base imbalance?
A. Uncompensated metabolic acidosis
B. Partially compensated metabolic acidosis
C. Fully compensated respiratory acidosis
D. Mixed metabolic and respiratory alkalosis
CORRECT ANSWER B — Partially compensated metabolic acidosis.
RATIONALE pH 7.28 = acidosis. HCO₃⁻ 16 = low — primary metabolic acidosis. PaCO₂ 32 = low
(<35) — the lungs are hyperventilating (Kussmaul respirations) to compensate by
blowing off CO₂. ALL THREE values are abnormal, but pH is still not normal =
partially compensated. The lungs are attempting to correct a metabolic problem,
but compensation is incomplete.
4. A 55-year-old woman with prolonged vomiting has ABG: pH 7.47, PaCO₂ 48 mmHg, HCO₃⁻
30 mEq/L. What is the acid-base imbalance?
A. Uncompensated metabolic alkalosis
B. Partially compensated metabolic alkalosis
C. Fully compensated respiratory acidosis
D. Uncompensated respiratory alkalosis
CORRECT ANSWER B — Partially compensated metabolic alkalosis.
RATIONALE pH 7.47 = alkalosis. HCO₃⁻ 30 = elevated — primary metabolic alkalosis (loss of
gastric HCl from vomiting). PaCO₂ 48 = elevated — compensatory hypoventilation
(retaining CO₂/acid). ALL THREE values are abnormal, but pH is still not normal =
partially compensated. The lungs are attempting to correct a metabolic alkalosis
by retaining CO₂, but haven't fully normalized pH yet.
, 5. A patient's ABG: pH 7.36, PaCO₂ 50 mmHg, HCO₃⁻ 30 mEq/L. What is the acid-base
imbalance?
A. Uncompensated respiratory acidosis
B. Partially compensated metabolic alkalosis
C. Fully compensated respiratory acidosis
D. Fully compensated metabolic alkalosis
CORRECT ANSWER C — Fully compensated respiratory acidosis.
RATIONALE pH 7.36 = normal (barely acidic side). PaCO₂ 50 = elevated — primary respiratory
acidosis. HCO₃⁻ 30 = elevated — renal compensation (retaining base). pH is normal
while BOTH other values are abnormal = fully compensated. This is typical of
chronic COPD — the kidneys have fully compensated for chronic CO₂ retention by
retaining bicarbonate over days to weeks.
6. A patient with sepsis presents with ABG: pH 7.10, PaCO₂ 55 mmHg, HCO₃⁻ 15 mEq/L. What
acid-base imbalance is most likely?
A. Uncompensated respiratory acidosis only
B. Mixed respiratory and metabolic acidosis
C. Partially compensated metabolic alkalosis
D. Fully compensated respiratory alkalosis
CORRECT ANSWER B — Mixed respiratory and metabolic acidosis.
RATIONALE pH 7.10 is severely acidotic. BOTH PaCO₂ is elevated (respiratory acidosis —
hypoventilation or impaired gas exchange from sepsis) AND HCO₃⁻ is low
(metabolic acidosis — lactic acidosis from sepsis-induced hypoperfusion). When
both components drive pH in the same direction beyond what simple
compensation would allow, it is a MIXED disorder. Sepsis commonly causes mixed
acidosis: lactic acid (metabolic) + hypoperfusion/respiratory failure (respiratory).
