Respiratory Acidosis



Respiratory Acidosis is an acid-base imbalance characterized by increased partial pressure of arterial carbon dioxide and decreased blood pH. The prognosis depends on the severity of the underlying disturbance as well as the patient’s general clinical condition.

Compensatory mechanisms include (1) an increased respiratory rate; (2) hemoglobin (Hb) buffering, forming bicarbonate ions and deoxygenated Hb; and (3) increased renal ammonia acid excretions with reabsorption of bicarbonate.

Acute respiratory acidosis: Associated with acute pulmonary edema, aspiration of foreign body, overdose of sedatives/barbiturate poisoning, smoke inhalation, acute laryngospasm, hemothorax/pneumothorax, atelectasis, adult respiratory distress syndrome (ARDS), anesthesia/surgery, mechanical ventilators, excessive CO2 intake (e.g., use of rebreathing mask, cerebral vascular accident [CVA] therapy), Pickwickian syndrome.

Chronic respiratory acidosis: Associated with emphysema, asthma, bronchiectasis; neuromuscular disorders (such as Guillain-Barré syndrome and myasthenia gravis); botulism; spinal cord injuries.



  • Shock
  • Cardiac Arrest

Signs and Symptoms

Signs and Symptoms of Respiratory Acidosis

  • CNS disturbances: restlessness, confusion, and apprehension to somnolence with fine flapping tremor, or coma.
  • Headache
  • Dyspnea
  • Tachypnea
  • Increase in blood pressure
  • Mental cloudiness and feeling of fullness in head
  • Weakness


Assessment cues are dependent on underlying cause.


  • May report: Fatigue, mild to profound
  • May exhibit: Generalized weakness, ataxia/staggering, loss of coordination (chronic), to stupor


  • May exhibit: Low BP/hypotension with bounding pulses, pinkish color, warm skin (reflects vasodilation of severe acidosis)
  • Tachycardia, irregular pulse (other/various dysrhythmias)
  • Diaphoresis, pallor, and cyanosis (late stage)



  • May report: Feeling of fullness in head (acute—associated with vasodilation)
  • Headache, dizziness, visual disturbances
  • May exhibit: Confusion, apprehension, agitation, restlessness, somnolence; coma (acute)
  • Tremors, decreased reflexes (severe)


  • May report: Shortness of breath; dyspnea with exertion
  • May exhibit: Respiratory rate dependent on underlying cause, i.e., decreased in respiratory center depression/
  • muscle paralysis; otherwise rate is rapid/shallow
  • Increased respiratory effort with nasal flaring/yawning, use of neck and upper body muscles
  • Decreased respiratory rate/hypoventilation (associated with decreased function of respiratory center as in head trauma, oversedation, general anesthesia, metabolic alkalosis)
  • Adventitious breath sounds (crackles, wheezes); stridor, crowing


  • Refer to specific plans of care reflecting individual predisposing/contributing factors.

Diagnostic Studies

  • CONFIRMING DIAGNOSIS: Arterial blood gas (ABG) analysis of
    • PaCO2 higher than 45 mm Hg
    • pH is below normal range of 7.35 to 7.45
    • bicarbonate level is normal (acute) or elevate (in chronic stages)
  • Chest X-ray, CT scan can help determine the cause
  • ABGs: Pao2: Normal or may be low. Oxygen saturation (Sao2) decreased.
  • Paco2: Increased, greater than 45 mm Hg (primary acidosis).
  • Bicarbonate (HCO3): Normal or increased, greater than 26 mEq/L (compensated/chronic stage).
  • Arterial pH: Decreased, less than 7.35.
  • Electrolytes: Serum potassium: Typically increased.
  • Serum chloride: Decreased.
  • Serum calcium: Increased.
  • Lactic acid: May be elevated.
  • Urinalysis: Urine pH decreased.
  • Other screening tests: As indicated by underlying illness/condition to determine underlying cause.

Nursing Diagnosis

The following are the possible nursing diagnosis for Respiratory Acidosis:

Nursing Priorities

  1. Achieve homeostasis.
  2. Prevent/minimize complications.
  3. Provide information about condition/prognosis and treatment needs as appropriate.

Discharge Goals

  1. Physiological balance restored.
  2. Free of complications.
  3. Condition, prognosis, and treatment needs understood.
  4. Plan in place to meet needs after discharge.

Care Setting

This condition does not occur in isolation, but rather is a complication of a broader health problem/disease or condition for which the severely compromised patient requires admission to a medical-surgical or subacute unit.

Nursing Care Plans

Main Article: Respiratory Acidosis Nursing Care Plan

Nursing Interventions & Considerations

  • Remain alert for critical changes in patient’s respiratory, CNS and cardiovascular functions. Report such changes as well as any variations in ABG values or electrolyte status immediately.
  • Maintain adequate hydration.
  • Maintain patent airway and provide humidification if acidosis requires mechanical ventilation. Perform tracheal suctioning frequently and vigorous chest physiotherapy, if ordered.
  • Institute safety measures and assist patient with positioning.
  • Continuously monitor arterial blood gases.

See Also


Matt Vera is a registered nurse with a bachelor of science in nursing since 2009 and is currently working as a full-time writer and editor for Nurseslabs. During his time as a student, he knows how frustrating it is to cram on difficult nursing topics. Finding help online is nearly impossible. His situation drove his passion for helping student nurses by creating content and lectures that are easy to digest. Knowing how valuable nurses are in delivering quality healthcare but limited in number, he wants to educate and inspire nursing students. As a nurse educator since 2010, his goal in Nurseslabs is to simplify the learning process, break down complicated topics, help motivate learners, and look for unique ways of assisting students in mastering core nursing concepts effectively.