Respirations & ABGs Study Guide

Respirations Study Guide (LO 19.4)

• Definitions:
  • Respiration: The act of breathing.
  • Hypoxemia: Low oxygen levels in the blood.
  • Hypercapnia: High levels of carbon dioxide.
  • Oxygen Saturation: Amount of oxygen in arterial blood.
  • Hypoventilation: Shallow respirations.
  • Hyperventilation: Deep, rapid respirations.
  • Pulmonary ventilation: Movement of air into and out of the lungs.
  • Inspiration (Inhalation): Breathing in.
  • Expiration (Exhalation): Breathing out.
  • Eupnea: Normal, regular breathing pattern.
  • Tachypnea: Increased respiratory rate (>20 breaths per minute in adults).
  • Bradypnea: Decreased respiratory rate (<10 breaths per minute in adults).
  • Apnea: Absence of breathing.
  • Dyspnea: Difficult, labored breathing.
  • Orthopnea: Difficulty breathing when lying flat, relieved by sitting or standing.
  • Cyanosis: Bluish discoloration of skin/mucous membranes due to low oxygen.

Physiology & Regulation of Breathing

• Respiratory Centers: Located in the medulla and pons.
• Stimuli for Breathing:
  • Impulses from chemoreceptors.
  • Most strongly stimulated by increased carbon dioxide (hypercapnia).
  • Also influenced by low oxygen levels (hypoxemia) and pH changes.
• Chemoreceptors:
  • Located in the aortic arch and carotid arteries.
  • Sensitive to oxygen levels.
  • Receptors in the medulla respond to CO₂ and pH.
• Other Inputs:
  • Stretch receptors in lungs.
  • Receptors in muscles and joints.
• Voluntary Control: Via cerebral cortex (e.g., singing, holding breath).

Factors Affecting Respirations

• Age: Respiratory rate decreases with age.
• Exercise: Increases rate and depth.
• Illness:
  • Cardiovascular and hematologic disorders can increase rate.
  • Pulmonary diseases alter breathing patterns.
• Fluid & Electrolyte Imbalances: Affect respiratory effort.
• Acid-Base Balance:
  • Acidosis → increased rate/depth.
  • Alkalosis → decreased rate.
• Medications:
  • Narcotics & anesthesia slow breathing.
  • Stimulants (amphetamines, cocaine) increase rate.
  • Bronchodilators slow respiratory rate.
• Pain: Increases rate, decreases depth.
• Emotions: Fear, anxiety increase rate.

Assessment of Respirations

• What to assess:
  • Rate: Breaths per minute.
  • Depth: Shallow or deep.
  • Rhythm: Regular or irregular.
  • Oxygen saturation (SpO₂): Normal 95-100%.
• Preparation:
  • Know the patient’s baseline.
  • Consider medication effects and health conditions.
• Procedure:
  • Observe chest and abdomen for effort and symmetry.
  • Count breaths for 30-60 seconds.
  • Note use of accessory muscles, effort, and symmetry.

Respiratory Patterns & Abnormalities

• Normal breathing: Eupnea.
• Rapid shallow breathing: Tachypnea.
• Slow breathing: Bradypnea.
• Deep, rapid breathing: Hyperventilation.
• Shallow respirations: Hypoventilation.
• Absent breathing: Apnea.
• Difficulty breathing: Dyspnea, often with accessory muscle use.
• Positioning:
  • Orthopnea: Breathing difficulty lying flat.
  • Upright position eases dyspnea.

Oxygen Saturation (SpO₂)

• Normal range: 95-100%.
• Measurement:
  • Noninvasive pulse oximetry.
  • Sensor placed on fingertip, toe, nose, or earlobe.
  • Uses infrared light to measure hemoglobin oxygenation.
• Factors affecting accuracy:
  • Cold, injury, edema, jaundice.
  • Movement, shivering, nail polish.
• Importance:
  • Indicates oxygenation status.
  • Decreased SpO₂ and cyanosis indicate hypoxemia.
  • Changes require prompt assessment and intervention.

Summary

• Maintain smooth, effortless breathing.
• Monitor for changes in rate, depth, and oxygen saturation.
• Recognize abnormal patterns to assess patient status.
• Use pulse oximetry as a critical tool for oxygenation assessment.

Arterial Blood Gases (ABGs) Study Guide

• Definitions:
  • Arterial Blood Gases (ABGs): Blood test measuring oxygen, carbon dioxide, pH, and bicarbonate to assess respiratory and metabolic balances.
  • pH: Indicates acidity or alkalinity of blood.
  • Carbon Dioxide (CO₂): Reflects respiratory function.
  • Oxygenation: Measured via partial pressure of oxygen (PaO₂).

Purpose of ABGs

• Assess respiratory component of acid-base balance.
• Evaluate oxygenation status.
• Establish baseline values.
• Identify respiratory disorders.
• Monitor critically ill patients.
• Determine response to treatment.

Why Arterial Blood?

• Arterial blood gases are used because venous blood values vary depending on tissue metabolism.
• ABGs provide a more accurate assessment of oxygen and CO₂ levels.

Signs of Respiratory Distress (SAFE PRACTICE ALERT)

• Use of accessory muscles (chest/neck).
• Exaggerated effort to breathe.
• Children/Infants:
  • Nasal flaring.
  • Sternal retractions.

Nursing Diagnoses Supported by Respiratory Assessment

• Impaired Breathing
  • Supporting Data: Increased intracranial pressure, hypoventilation.
• Impaired Gas Exchange
  • Supporting Data: Alveolar changes, oxygen saturation of 89% on room air.
• Activity Intolerance
  • Supporting Data: Low oxygen levels, dyspnea on exertion.

Planning and Goals

• Ensure adequate oxygen delivery.
• Examples of goals:
  • Patients exhibit regular breathing patterns with ventilator support.
  • ABGs within normal range within 8 hours.
  • Able to perform daily activities without increased dyspnea before discharge.

Implementation

• Count respirations for 1 minute using a watch with a sweep second hand.
• Count when a patient is unaware to prevent voluntary control.
• For shallow/slow respirations:
  • Use a stethoscope to auscultate breath sounds.
  • Palpate the chest or abdomen to feel for breaths.
• Use apnea monitors to detect chest movement and alert for apnea episodes.
  • Common in infants and sleep monitoring for adults.

Evaluation

• Monitor respiratory rate, rhythm, and pattern.
• Observe for signs of hypoxia or altered breathing.
• Check oxygen saturation (SpO₂).
• Report abnormal findings to healthcare provider.
• Follow-up on interventions (oxygen therapy, medications, positioning).

Summary

• ABGs are critical in evaluating respiratory function.
• Recognize signs of distress and abnormal patterns.
• Accurate assessment and timely intervention improve patient outcomes.
• Continuous monitoring and evaluation are essential for effective respiratory management.