A
A client with type 1 diabetes mellitus arrives with polyuria, abdominal pain, fruity breath, and Kussmaul respirations. The laboratory report shows glucose 548 mg/dL.
ABG VALUES: pH 7.24 | PaCO₂ 28 mmHg | HCO₃⁻ 12 mEq/L
How should the practical nurse interpret these ABG results?
A. Uncompensated respiratory acidosis
B. Partially compensated metabolic acidosis
C. Partially compensated metabolic alkalosis
D. Fully compensated respiratory alkalosis
Correct Answer: B Partially compensated metabolic acidosis
Rationale: The pH is acidic and the HCO₃⁻ is low, identifying metabolic acidosis. The PaCO₂ is also low because the lungs are attempting to compensate through rapid, deep respirations. The pH remains abnormal, so compensation is partial.
A client with profuse diarrhea has weakness and orthostatic hypotension.
ABG VALUES: pH 7.28 | PaCO₂ 32 mmHg | HCO₃⁻ 15 mEq/L
Which explanation best connects the diagnosis with the ABG results?
A. Diarrhea causes retention of bicarbonate, producing alkalosis
B. Diarrhea causes loss of bicarbonate, producing metabolic acidosis
C. Diarrhea causes carbon dioxide retention, producing respiratory acidosis
D. Diarrhea causes excessive acid loss, producing metabolic alkalosis
B
Rationale: The gastrointestinal tract contains bicarbonate. Profuse diarrhea can cause bicarbonate loss, resulting in metabolic acidosis. The low PaCO₂ reflects respiratory compensation
A client with sepsis has a temperature of 39.4°C (102.9°F), blood pressure 82/46 mmHg, and altered mental status.
ABG VALUES: pH 7.25 | PaCO₂ 30 mmHg | HCO₃⁻ 13 mEq/L
Which provider prescription should the nurse implement first?
A. Begin the prescribed isotonic IV fluid bolus
B. Offer oral fluids
C. Place the client flat and wait 30 minutes
D. Administer a prescribed sedative
A
Rationale: The client has shock with partially compensated metabolic acidosis, likely from lactic acid accumulation. Rapid restoration of circulating volume with prescribed isotonic fluids is a priority while sepsis treatment proceeds.
A client with major burns has poor peripheral perfusion and decreasing urine output despite initial treatment.
ABG VALUES: pH 7.31 | PaCO₂ 33 mmHg | HCO₃⁻ 17 mEq/L
Which assessment finding best supports the cause of the ABG imbalance?
A. Capillary refill of 5 seconds
B. Hyperactive bowel sounds
C. Warm, dry skin
D. Bounding peripheral pulses
A
Rationale: The ABG shows partially compensated metabolic acidosis. Delayed capillary refill supports inadequate tissue perfusion, which can increase lactic acid production.
A client taking a loop diuretic has weakness, irregular heart rhythm, and poor appetite.
ABG VALUES: pH 7.50 | PaCO₂ 46 mmHg | HCO₃⁻ 33 mEq/L
Which nursing assessment is most important?
A. Review the serum potassium level and cardiac rhythm
B. Measure pupil size
C. Assess for neck stiffness
D. Test stool for occult blood
A
Rationale: The ABG shows partially compensated metabolic alkalosis. Loop diuretics can cause potassium loss, and hypokalemia increases the risk for dysrhythmias.
A client has experienced repeated vomiting for 3 days. The client reports weakness and muscle cramping. The nurse notes dry mucous membranes.
ABG VALUES: pH 7.50 | PaCO₂ 47 mmHg | HCO₃⁻ 34 mEq/L
Which acid-base imbalance is most consistent with these findings?
A. Partially compensated metabolic alkalosis
B. Uncompensated respiratory alkalosis
C. Partially compensated metabolic acidosis
D. Fully compensated respiratory acidosis
A Partially compensated metabolic alkalosis
Rationale: The pH is alkalotic and the HCO₃⁻ is elevated, indicating metabolic alkalosis from loss of gastric acid. The elevated PaCO₂ reflects hypoventilatory compensation. Because the pH is still abnormal, compensation is partial.
A client with end-stage kidney disease missed two dialysis treatments and is confused, nauseated, and weak.
ABG VALUES: pH 7.19 | PaCO₂ 35 mmHg | HCO₃⁻ 13 mEq/L
Which finding should the nurse report immediately with these ABG results?
A. Potassium 6.4 mEq/L
B. Hemoglobin 10.2 g/dL
C. Phosphorus 5.2 mg/dL
D. Creatinine 6.8 mg/dL
A
Rationale: The client has uncompensated metabolic acidosis. Severe hyperkalemia is immediately life-threatening because it can cause fatal dysrhythmias and requires urgent reporting and treatment.
A client with a severe asthma exacerbation was initially tachypneic. The client is now fatigued, has diminished breath sounds, and can speak only one word at a time.
ABG VALUES: pH 7.28 | PaCO₂ 52 mmHg | HCO₃⁻ 24 mEq/L
How should the nurse interpret the change in the client's condition?
A. The asthma attack is resolving
B. Carbon dioxide retention suggests impending respiratory failure
C. The client is developing metabolic alkalosis
D. The ABG is expected and requires no action
B
Rationale: In severe asthma, a rising PaCO₂ with acidemia and fatigue is an ominous sign. It indicates inadequate ventilation and possible impending respiratory failure.
A client arrives after taking a large amount of aspirin. The client has tinnitus, nausea, and rapid respirations.
ABG VALUES: pH 7.48 | PaCO₂ 27 mmHg | HCO₃⁻ 20 mEq/L
Which interpretation is most accurate?
A. Partially compensated respiratory alkalosis
B. Uncompensated metabolic alkalosis
C. Partially compensated respiratory acidosis
D. Fully compensated metabolic acidosis
A
Rationale: Early salicylate toxicity stimulates the respiratory center, producing respiratory alkalosis. The low HCO₃⁻ indicates metabolic compensation, but the pH remains alkalotic
A client receiving mechanical ventilation becomes restless after the respiratory rate setting is increased.
ABG VALUES: pH 7.55 | PaCO₂ 25 mmHg | HCO₃⁻ 22 mEq/L
Which action should the nurse take?
A. Notify the respiratory therapist and provider that the client may be overventilated
B. Increase the ventilator respiratory rate
C. Administer sodium bicarbonate
D. Clamp the endotracheal tube
A
Rationale: The ABG shows uncompensated respiratory alkalosis caused by excessive removal of carbon dioxide. Ventilator settings require prompt evaluation and adjustment by the appropriate team member.
An older adult with severe dehydration from poor oral intake has tachycardia, hypotension, decreased urine output, and cool extremities.
ABG VALUES: pH 7.30 | PaCO₂ 31 mmHg | HCO₃⁻ 15 mEq/L
Which interpretation and cause are most accurate?
A. Respiratory alkalosis caused by anxiety
B. Metabolic alkalosis caused by volume loss
C. Partially compensated metabolic acidosis caused by poor tissue perfusion
D. Respiratory acidosis caused by hypoventilation
C
Rationale: The acidic pH and low HCO₃⁻ indicate metabolic acidosis. The low PaCO₂ shows respiratory compensation. Severe dehydration can reduce tissue perfusion and contribute to lactic acid accumulation.
A postoperative client received repeated IV opioid doses. The client is difficult to arouse, with respirations of 7/min and pinpoint pupils.
ABG VALUES: pH 7.23 | PaCO₂ 64 mmHg | HCO₃⁻ 26 mEq/L
Which prescription should the nurse anticipate implementing first?
A. Naloxone and ventilatory support
B. Oral potassium replacement
C. Sodium bicarbonate infusion
D. Fluid restriction
A
Rationale: The ABG indicates acute uncompensated respiratory acidosis caused by opioid-induced hypoventilation. Reversal with naloxone and support of ventilation are priorities.
A client with a prolonged tonic-clonic seizure has been stabilized. The client remains tachycardic and confused.
ABG VALUES: pH 7.17 | PaCO₂ 29 mmHg | HCO₃⁻ 10 mEq/L
Which process most likely explains these ABG results?
A. Lactic acid accumulation from intense muscle activity
B. Loss of gastric acid from vomiting
C. Chronic carbon dioxide retention
D. Excessive bicarbonate ingestion
A
Rationale: The values show partially compensated metabolic acidosis. Prolonged seizure activity can cause tissue hypoxia and lactic acid production.
A client has just been resuscitated after cardiac arrest. The client remains hypotensive with weak peripheral pulses.
ABG VALUES: pH 7.09 | PaCO₂ 54 mmHg | HCO₃⁻ 16 mEq/L
How should the nurse interpret these results?
A. Mixed respiratory and metabolic acidosis
B. Fully compensated respiratory acidosis
C. Uncompensated metabolic alkalosis
D. Mixed respiratory and metabolic alkalosis
A
Rationale: The pH is severely acidic, PaCO₂ is elevated, and HCO₃⁻ is low. Both respiratory and metabolic components are contributing to the acidemia, which is common after cardiac arrest.
A client with severe dehydration from heat exposure has tachycardia, hypotension, confusion, and a serum lactate of 5.1 mmol/L.
ABG VALUES: pH 7.27 | PaCO₂ 29 mmHg | HCO₃⁻ 13 mEq/L
Which outcome best indicates that treatment is effective?
A. Urine output increases to at least 30 mL/hr
B. PaCO₂ decreases to 20 mmHg
C. Respiratory rate increases to 36/min
D. Serum bicarbonate decreases to 10 mEq/L
A
Rationale: The client has partially compensated metabolic acidosis from hypoperfusion. Improved urine output indicates better renal perfusion and circulating volume.
A client with chronic obstructive pulmonary disease is increasingly drowsy. Respirations are 10/min and shallow. Oxygen saturation is 86%.
ABG VALUES: pH 7.29 | PaCO₂ 61 mmHg | HCO₃⁻ 28 mEq/L
Which action should the nurse take first?
A. Encourage the client to drink water
B. Place the client in high-Fowler position and assess airway and breathing
C. Administer sodium bicarbonate
D. Ask the client to rebreathe into a paper bag
B
Rationale: The client has partially compensated respiratory acidosis with hypoxemia and declining level of consciousness. Airway and breathing are the priority. Positioning, focused respiratory assessment, oxygen per order, and prompt escalation are indicated.
A client with acute pulmonary edema is extremely dyspneic, anxious, and coughing pink frothy sputum.
ABG VALUES: pH 7.48 | PaCO₂ 29 mmHg | HCO₃⁻ 22 mEq/L
Which interpretation is correct?
A. Uncompensated respiratory alkalosis
B. Uncompensated metabolic alkalosis
C. Partially compensated respiratory acidosis
D. Fully compensated metabolic acidosis
A
Rationale: The pH is alkalotic and the PaCO₂ is low, showing respiratory alkalosis from rapid breathing. The HCO₃⁻ is within normal range, so there is no metabolic compensation.
A client with fever and early gram-negative sepsis is breathing 30 times/min but has a blood pressure of 118/72 mmHg.
ABG VALUES: pH 7.47 | PaCO₂ 30 mmHg | HCO₃⁻ 21 mEq/L
Which acid-base imbalance is present?
A. Partially compensated respiratory alkalosis
B. Partially compensated metabolic alkalosis
C. Uncompensated respiratory acidosis
D. Fully compensated metabolic acidosis
A
Rationale: The pH is alkalotic and PaCO₂ is low, making respiratory alkalosis primary. HCO₃⁻ is slightly low, showing metabolic compensation. The pH remains abnormal, so compensation is partial.
A client with pneumonia has a history of chronic lung disease. The client is alert and reports that breathing feels 'about normal.'
ABG VALUES: pH 7.36 | PaCO₂ 52 mmHg | HCO₃⁻ 29 mEq/L
Which interpretation is correct?
A. Fully compensated respiratory acidosis
B. Uncompensated respiratory acidosis
C. Fully compensated metabolic alkalosis
D. Partially compensated respiratory alkalosis
Answer: A
Rationale: The pH is within normal limits but on the acidic side. PaCO₂ is elevated, indicating respiratory acidosis, and HCO₃⁻ is elevated as renal compensation. A normal pH indicates full compensation.
A client with neuromuscular weakness develops shallow respirations and increasing somnolence.
ABG VALUES: pH 7.21 | PaCO₂ 63 mmHg | HCO₃⁻ 25 mEq/L
Which finding requires immediate intervention?
A. Inability to maintain a patent airway
B. Mild thirst
C. Urine specific gravity of 1.020
D. Temperature of 37.2°C (99°F)
A
Rationale: The client has acute uncompensated respiratory acidosis due to inadequate ventilation. Loss of airway protection is immediately life-threatening.
A client is having a panic attack and is breathing 34 times/min. The client reports tingling around the mouth and fingers.
ABG VALUES: pH 7.53 | PaCO₂ 27 mmHg | HCO₃⁻ 23 mEq/L
Which nursing intervention is most appropriate?
A. Coach the client to slow breathing and remain with the client
B. Administer an antacid
C. Restrict oral fluids
D. Prepare to administer sodium bicarbonate
A
Rationale: The ABG shows uncompensated respiratory alkalosis caused by hyperventilation. Calm coaching and treatment of the cause are appropriate. Paper-bag breathing is not recommended because it may worsen unrecognized hypoxemia.
A client has had continuous nasogastric suction for 48 hours and now reports weakness and dizziness.
ABG VALUES: pH 7.49 | PaCO₂ 48 mmHg | HCO₃⁻ 35 mEq/L
Which additional laboratory result should the nurse expect?
A. Potassium 2.9 mEq/L
B. Potassium 5.9 mEq/L
C. Chloride 112 mEq/L
D. Glucose 52 mg/dL
A
Rationale: Loss of gastric hydrochloric acid causes metabolic alkalosis, often accompanied by hypokalemia and hypochloremia. The elevated PaCO₂ indicates partial respiratory compensation.
A client with a traumatic brain injury has slow, shallow respirations and a declining Glasgow Coma Scale score.
ABG VALUES: pH 7.26 | PaCO₂ 57 mmHg | HCO₃⁻ 25 mEq/L
Which nursing action has the highest priority?
A. Prepare for airway support and notify the rapid response team
B. Encourage ambulation
C. Administer an oral antacid
D. Restrict dietary protein
A
Rationale: The client has acute uncompensated respiratory acidosis from hypoventilation. A declining neurologic status threatens airway protection and ventilation, requiring urgent escalation.
A client with advanced cirrhosis is tachypneic and increasingly confused.
ABG VALUES: pH 7.48 | PaCO₂ 31 mmHg | HCO₃⁻ 23 mEq/L
Which acid-base imbalance should the nurse document?
A. Uncompensated respiratory alkalosis
B. Uncompensated metabolic alkalosis
C. Partially compensated respiratory acidosis
D. Fully compensated metabolic acidosis
A
Rationale: The elevated pH and low PaCO₂ indicate respiratory alkalosis. The bicarbonate remains within normal range, so compensation has not occurred.
A client with adrenal insufficiency has vomiting, abdominal pain, hypotension, and generalized weakness.
ABG VALUES: pH 7.29 | PaCO₂ 34 mmHg | HCO₃⁻ 16 mEq/L
Which additional finding should the nurse anticipate?
A. Hyperkalemia
B. Hypokalemia
C. Hypernatremia
D. Severe metabolic alkalosis
A
Rationale: The ABG indicates partially compensated metabolic acidosis. Adrenal insufficiency can cause impaired sodium retention and potassium excretion, leading to hyponatremia and hyperkalemia.