Oxygen therapy devices

• Sao2: arterial oxygen saturation
• FiO2: fraction of inspired oxygen
• PaO2: arterial partial pressure of oxygen (mmHg)
• SpO2: oxygen saturation detected via pulse oximeter
• The concentration of oxygen in ambient air is 21%
• Hypoxemia is a state of low oxygen tension in the blood. Hypoxemia can lead to hypoxia if not corrected
• Hypoxia is a condition in which in the PaO2 (partial oxygen pressure) has fallen sufficiently to cause signs and symptoms of inadequate oxygenation.
• Hypercapnia is the presence of excessive amounts of CO2 in the blood
• Manifestations of hypoxemia

  • dysrhythmia
  • fatigue
  • diaphoresis
  • hypertension
  • tachycardia
  • deterioration of LOC
  • use of accessory muscles
  • dyspnea and tachypnea
• Hypercapnia manifestations

  • dyspnea
  • fatigue
  • confusion that may progress to drowsiness
  • headache
  • dizziness
  • nausa
• The pulse oximeter is a non-invasive method of assessing arterial oxygen saturations. A healthy patient normally has an SpO2 of 97-98% but 95% is acceptable
• Indications for oxygen

  • hypoxemia
  • SpO2 outside targeted parameters
  • acute or chronic respiratory condition
  • pre and post suction
  • emergency situations
• Contraindications for nasal cannula

  • nasal obstruction
  • epistaxis
  • nasal polyps
  • nasal surgery
• Patient should be monitored every 15-30 minutes after initiation of oxygen therapy or until saturation is stable. When stable, monitor every 4-8 hours
• Monitoring

  • pulse oximeter for SpO2
  • blood sampling
  • signs and symptoms of hypoxemia or hypercapnia
• The flow meter is used to regulate and control the volume of O2 leaving the source used. It is graduated by L per min
• Nasal cannula

  • inserted in nostrils
  • flexible low rate of 1-6L per minute
  • able to provide 24-40% FiO2
  • patient can easily eat, drink and talk
• Venturi mask

  • flexible flow rate of 2-15 L per minute
  • multiple adapters each offering a fixed concentration of 24, 28, 31, 35, 40 or 50% oxygen
• Face mask

  • flexible flow rate of 5-12L per minute
  • provides 40-70% oxygen
  • can have a valve or be valveless (allows partial rebreathing of exhaled air)
  • high humidity mask
• Non-rebreather mask

  • flexible flow rate of 10-15L per min
  • provides 60-100% oxygen
  • reservoir must stay inflated on inspiration and expiration
• Nebulizer allows for the administration of liquid drugs via aerolization. It disperses a drug in the form of fine droplets suspended in O2
• Humidifier is needed for high oxygen flow rate (over 4L per min). It prevents dryness and irritation of mucous membrane. Passage of oxygen through the water creates bubble which humidify the air coming from the O2 source
• Epistaxis comes from excessive dryness of the mucus membranes
• Pressure injuries are possible due to the nasal cannula. Check ear, nose, cheeks and chin for pressure injuries
• Hyperoxemia can be caused by the administration of a prolonged high level of oxygen. It can lead to alveolar membrane damage and decreased lung compliance
• Oxygen induced hypoventilation is possible in COPD patients because they retain CO2
• Infection is possible with the constant use of humidity, which supports bacterial growth
• Complications of oxygen therapy

  • epistaxis (nose bleed)
  • pressure injuries
  • hyperoxemia
  • oxygen induced hypoventilation
  • infection