Oxygen Therapy

• Oxygen


  • A colorless, odorless, tasteless gas
  • Slightly heavier than air
  • Essential for life
  • Optimum level must be maintained to sustain mental functioning
  • Considered as a drug

  
• Oxygen therapy


  • Administration of oxygen at a concentration greater than that found in the environmental atmosphere (>21%)
  • A treatment that provides extra oxygen to the tissues of the body through the lungs and is provided to a patient as a supplement to normal respiration
• Oxygen prescription


  • Prescribed by the physician, who specifies the specific concentration, method & liter flow per minute
  • Prescribed in liters per minute (Lpm, L/min)
  • As a concentration (%)
  • As a fraction of inspired oxygen (Fio2)

  
• Approximate oxygen concentrations delivered


  • 1L = 24% to 25%
  • 2L = 27% to 29%
  • 3L = 30% to 33%
  • 4L= 33% to 37%
  • 5L = 36% to 41%
  • 6L = 39% to 45%
• As an emergency measure, the nurse may initiate the therapy without the physician's order (ONLY 1-2 liters per minute)
• Safety precautions


  • Oxygen by itself will not burn or explode, but it does facilitate combustion
  • Cautionary signs - client's door, at the foot or head of the bed, & on the oxygen equipment
  • Instruct the client & visitors about the hazard of smoking with oxygen in use
  • Avoid (-) materials that generate static electricity (woolen blankets & synthetic fabrics)
  • Use (+) cotton blankets and cotton fabrics
  • Ground electric monitoring equipment
  • Avoid the use of volatile, flammable materials
  • Do not drop or roll cylinders
  • Do not completely empty cylinders
  • Do not expose tanks to extreme heat or flame

  
• Oxygen equipment


  • Medical oxygen tank/source
  • Regulator (pressure gauge, pressure-reducing valve & flow meter)
  • Tubing
  • Humidifier
  • O2 stand
  • Nasal cannula/catheter/face mask etc. (depending on method to be used)

  
• Oxygen cylinder


  Usually painted green or has distinctive green markings
• Oxygen regulator


  • Includes the pressure gauge, pressure-reducing valve & the flow meter
  • Regulates oxygen pressure
  • Allows delivery of oxygen to the patient at flow rates between 1 & 15 lpm

  
• Oxygen pressure gauge


  • Indicates how much oxygen remains in the cylinder
  • Full tank - at least 2,000 pounds per square inch (psi)
  • Empty - less than 500 psi
• Oxygen humidifier


  • Adds water vapor to inspired air
  • Provides 20% to 40% humidity
  • Prevents mucous membranes from drying & becoming irritated
  • Loosens secretions for easier expectoration
• Methods of oxygen administration


  • Nasal cannula
  • Nasal catheter
  • Oxygen tent/hood
  • Manual resuscitation bag
  • Via ET or tracheostomy tube
  • Transtracheal catheter
  • Non-invasive positive pressure ventilator

  
• Nasal cannula


  • Most common method
  • Inexpensive
  • Delivers 24-45% oxygen at flow rates of 2-6 lpm
  • Can be used by older infants & children
  • Cannot deliver high O2 concentrations
  • Requires nose breathing
  • Dries the mucosa
  • Contraindicated in children with nasal obstruction
• Reservoir nasal cannula


  O2-conserving device
• Nasal catheter


  • Tube made of flexible rubber or plastic for delivering oxygen inserted through the nose into the posterior nasal pharynx
  • For mouth-breathers and claustrophobic clients
  • Not appropriate for neonates
  • Catheter tends to irritate the nasopharynx; can be uncomfortable
  • Measurement is from the tip of the pt's nose to the earlobe
  • Use water-based lubricant
  • Fr 8-10 (catheter)
  • Percentage of oxygen delivered (Fio2) varies with the child's inspiratory flow, liter flow is usually <3 L/min
  • Contraindicated in children with nasal obstruction (e.g., nasal polyps & choanal atresia), coagulation problems
• Face masks


  Advantages: Various sizes available; delivers higher O2 concentration than cannula

  Disadvantages: Skin irritation, Fear of suffocation, Accumulation of moisture on face, Possibility of aspiration vomitus, Difficulty in controlling O2 concentrations, Eating disrupts O2 delivery, Makes verbal communication difficult to understand (in older clients), Not appropriate for neonates
• Simple mask


  • With side vents
  • Provides a reservoir over the face into which oxygen flows
  • Delivers oxygen concentrations from 40-60% at 5-8 Lpm
  • Good for short-term use
  • Not well-tolerated by children
• Partial rebreather mask


  • With an inflatable bag that stores 100% oxygen
  • Some CO2 always remains within the mask & is reinhaled
  • Delivers oxygen concentrations of 50-60% at 6-10 Lpm
• Non-rebreather mask


  • With an inflatable bag and one-way valve
  • Delivers the highest oxygen concentration possible, 95-100% at flows of 6-10 Lpm
  • Used for those who require high concentrations of oxygen; usually critically ill & may eventually need mechanical ventilation

  
• Venturi mask


  • Mask with device that mixes a precise amount of atmospheric air & oxygen to deliver constant oxygen concentration
  • Delivers oxygen concentrations from 24-40% up to 50% at 3-15 Lpm
  • Has wide bore tubing & color coded jet adapters
• Face tent


  • "Face bucket" - soft piece of plastic sits beneath chin, mouth & nose not enclosed by plastic
  • Provide varying concentrations of oxygen; inconsistent
  • For clients with facial trauma or burns
• Oxygen tent


  • "Croup tent"
  • Replace masks if poorly tolerated by patients
  • For children beyond early infancy, most likely active toddlers
  • Provide 30-50% concentration of oxygen at 4-8 Lpm
  • Major difficulty is keeping the tent closed so that oxygen concentration is maintained
  • Some type of cooling mechanism such as an ice chamber or a refrigeration unit is provided to maintain the temperature at 20°C to 21°C (68°F to 70°F)
  • Child should be covered with a gown or cotton blanket
• Oxygen hood


  • A rigid plastic dome that encloses an infant's head
  • Provides precise oxygen levels & high humidity
  • At least 4 to 5 L/min of flow is needed to maintain oxygen concentrations & remove the exhaled carbon dioxide
  • Can deliver Fio2 of up to 100%
  • Provides easy visibility & access to the child, although it needs to be removed when feeding the child & giving care
  • An oxygen analyzer is needed to gauge the percentage of oxygen delivered
  • Humidified oxygen should not be blown directly into the face of an infant in a hood to prevent diving reflex, which causes bradycardia & shunting of blood from peripheral to central circulation
  • Temperature in hood needs to be monitored
• Manual resuscitation bags


  • Made of rubber or silicone, & forms part of the basic life support equipment in all clinical settings
  • Provides positive pressure ventilation & high concentration of oxygen to patient with insufficient inspiratory effort
• Endotracheal tube, tracheostomy tube, transtracheal catheter, and non-invasive positive pressure ventilator are also methods of oxygen administration

  
• Administering oxygen by nasal cannula


  1. Check doctor's order, including the administering device & the liter flow rate (L/min) or the percentage of oxygen (%, Fio2)

  2. Check client's ABG results: PaO2 is normally 80 to 100 mmHg, PaCO2 is normally 35 to 45 mmHg

  3. If the client has not had arterial blood gases ordered, oxygen saturation should be checked via pulse oximetry to monitor oxygen saturation (SaO2) & pulse rate, normally 98% to 100%

  
• Purposes of administering oxygen by nasal cannula


  • To deliver a relatively low concentration of oxygen when only minimal O2 support is required
  • To allow uninterrupted delivery of oxygen while the client ingests food or fluids
• Equipment for administering oxygen by nasal cannula

  • Oxygen supply with a flow meter & adapter
  • Plastic nasal cannula with connecting tubing
  • Humidifier with distilled water or tap water according to agency protocol
  • Tape
  • Padding for the elastic band
  • "NO SMOKING" sign

  
• Procedure for administering oxygen by nasal cannula


  1. Prepare the client & support people

  2. Introduce self & verify client's identity using agency protocol

  3. Perform hand hygiene & observe appropriate infection control procedures

  4. Provide for client privacy, if appropriate

  5. Set up the oxygen equipment & the humidifier

  6. Attach the connecting tube from the nasal cannula to the humidifier outlet

  7. Set flow rate at prescribed liters/minute. Feel to determine if oxygen is flowing through the tips of the cannula

  8. In newborns & in

  
• Administering oxygen by nasal cannula


  1. Perform hand hygiene & observe appropriate infection control procedures

  2. Provide for client privacy, if appropriate

  3. Set up the oxygen equipment & the humidifier

  4. Attach the connecting tube from the nasal cannula to the humidifier outlet

  5. Set flow rate at prescribed liters/minute

  6. Put the cannula over the client's face, with the outlet prongs fitting into the nares & the elastic band around the head

  7. Instruct the child/client to breathe through his nose

  8. Record flow rate used & immediate patient response

  9. Assess patient's condition, ABG or SaO2, & the functioning of equipment at regular intervals

  10. Determine patient comfort with oxygen use

  
• Administering oxygen by simple face mask

  1. Prepare the client & support people

  2. Prior to performing the procedure, introduce self & verify the client's identity using agency protocol

  3. Perform hand hygiene & observe appropriate infection control procedures

  4. Provide for client privacy, if appropriate

  5. Set up the oxygen equipment & the humidifier

  6. Set the desired oxygen concentration with the humidifier bottle

  7. Apply the mask toward the patient's face, from the nose downward

  8. Secure the elastic band around the client's head so that the mask is comfortable but snug

  9. Record patient's immediate response

  10. Assess the patient's condition & the functioning of equipment at regular intervals
• Administering oxygen via oxygen hood

  1. Prepare the client & support people

  2. Prior to performing the procedure, introduce self & verify the client's identity using agency protocol

  3. Perform hand hygiene & observe appropriate infection control procedures

  4. Remove all friction toys or open flames from the area

  5. Line the area that the hood covers on the bed with a waterproof pad

  6. Set up the oxygen equipment & the humidifier

  7. Connect the unit to the oxygen source

  8. Place the hood on the crib or bed so that the child's head should not rest on the child's neck, & the child should be able to turn his or her head to side easily

  9. Turn on the oxygen & humidifying unit to the prescribed setting

  10. Encourage family & other staff to limit the amount of time the child is outside of the hood
• Oxygen life span computation formula


  (Gauge pressure in psi - safe residual pressure) x cylinder constant / flow rate in L/min
• Safe residual pressure is 200 psi
• Cylinder constants


  • D = 0.16
  • E = 0.28
  • M = 1.56
  • G = 2.41
  • H = 3.14
  • K = 3.14
• Sample oxygen life span computation

  • H tank cylinder with 1,700 psi pressure and 10 L/min flow rate using NRB: 7 hours 51 minutes

  
• Oxygen life span computation assignment


  1. Determine the life of a D cylinder with 1,500 psi pressure and 3 L/min flow rate via nasal cannula

  2. Determine the life of a G tank with 1,600 psi pressure and 6 L/min flow rate via nasal cannula