oxygen delivery devices -picu
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This document discusses oxygen delivery devices and their use. It begins by outlining the goals of oxygen delivery which include maintaining oxygenation levels and reducing work of breathing. It then describes various oxygen delivery devices including nasal cannulas, masks, venturi masks, and tents. It provides details on how each device works, appropriate usage, advantages and disadvantages. It concludes by discussing humidification needs, factors in choosing a device, and additional advanced options like CPAP and high flow nasal prongs.
oxygen delivery devices -picu
- 1. Oxygen delivery devices Dr.Prasanna Narayanan.R
- 2. Goals of oxygen delivery • To maintain targeted SpO2 levels. • Relieve hypoxemia and maintain adequate oxygenation of tissues and vital organs. • Prevent excessive CO2 accumulation • Reduce the work of breathing • Efficient and economical use of oxygen • Ensure adequate clearance of secretions limit insensible water loss
- 3. Components • Oxygen source • Pressure regulator and flow meter • Oxygen delivery device • Patient
- 4. Oxygen • Wall source – Provide 50 psi (pounds per square inch ) of pressure • Cylinder – Operate at 1800-2400 psi – Cannot be directly delivered to patient or used to run the ventilator – Need down regulating valve – Flow meter to manipulate the flow rate
- 5. Pressure regulator with flow meter • The pressure regulator controls the pressure coming out of the cylinder and is indicated on the gauge in psi • The flow meter controls how rapidly the oxygen flows from the cylinder/wall source to the victim • The flow rate can be set from 1-25 L/min
- 6. Oxygen delivery devices • Devices used to administer, regulate, and supplement oxygen to increase the arterial oxygenation • system entrains oxygen and/or air to provide a fixed concentration required for administration • Tubing carries the oxygen from the regulator/flow meter to the delivery device
- 7. Classification Provide oxygen at flow rates that are lower than patients’ inspiratory demands When the total ventilation exceeds the capacity of the oxygen reservoir, room air is entrained FiO2 delivered depends on the ventilatory demands of the patient, the size of the oxygen reservoir, and the rate at which the reservoir is filled Low flow or variable performance devices Provide a constant FiO2 by delivering the gas at flow rates that exceed the patient’s peak inspiratory flow rate Devices entrain a fixed proportion of room air Reliable fio2 High-flow or fixed-performance devices:
- 8. • High-flow system The ventilatory demand of the patient is met completely by the system • Low-flow system if the system fails to meet the ventilatory demand of the patient:
- 9. • Flow systems often confused with oxygen concentrations • Both mutually exclusive • High-flow system, viz. Venturi mask, can deliver FiO2 as low as 0.24 • Whereas a low-flow system like a non- rebreathing mask can deliver FiO2 as high as 0.8
- 10. Oxygen delivery devices • Low flow systems: – Nasal cannula – Intranasal catheter – Simple mask – Partial rebreathing masks – Non rebreathing mask • High flow systems: – Venturi system – Oxyhood – Face tent – Oxygen tent – High flow nasal prongs CPAP Heliox Hyperbaric oxygen
- 11. Low-flow oxygen delivery system • requires that the patient inspire some room air to meet inspiratory demands • advantages: simplicity, patient comfort, and economical • FIO2 is determined by – the size of the oxygen reservoir, – the oxygen flow rate, – the breathing pattern
- 12. Choice of delivery device • Patient’s oxygen requirement • Efficacy of the device • Reliability • Ease of application • Humidification needs • Age • Patient acceptance and tolerance
- 13. • Normal flow requirement • 3-4 time the minute ventilation (MV = TV X RR) • eg 5 kgs child breathing at rates of 60/min • Flow rates needed: 3-4 X (60 X 6 X 5) = 5400- 7200 ml/min
- 14. Nasal cannula/prongs • Two soft prongs in nostrils attached to the oxygen source • Held in place over the patient’s ears • Flow is directed to the nasopharynx: humidification and heat exchange • To ensure the patient is able to entrain room air around the nasal prongs and a complete seal is not created the prong size should be approximately half the diameter of the nares • Available in different sizes • Select the appropriate size for the patient's age and size
- 15. Nasal cannula/prongs… • Delivers 24-44% FiO2 at flow rate of 1-6 L/min • A maximum flow of: – 2 LPM in infants/children under 2 years of age – 4 LPM for children over 2 years of age • With the above flow rates humidification is not usually required • flow >4 L/min - need humidification 1 = 24% 2 = 28% 3 = 32% 4 = 36% 5 = 40% 6 = 44%
- 16. Nasal cannula/prongs • Indications – Low to moderate oxygen requirement – No or mild respiratory distress – Long term oxygen therapy • Contraindications – Poor efforts, apnea, severe hypoxia – Mouth breathing • Advantages – Less expensive – Comfortable, well tolerated – Able to talk and eat • Disadvantages – Doesnot deliver high FiO2 – Irritation and nasal obstruction – Less FiO2 in nasal obstruction – FiO2 varies with breathing efforts
- 17. Nasal cannula/prongs… Practical considerations: • Position the nasal prongs along the patient's cheek and secure the nasal prongs on the patient's face with adhesive tape • Position the tubing over the ears and secure behind the patient's head • Ensure straps and tubing are away from the patient's neck to prevent risk of airway obstruction • Check nasal prong and tubing for patency, kinks or twists at any point in the tubing and clear or change prongs if necessary • Check nares for patency - clear with suction as required • Change the adhesive tape frequently as required • Check frequently that both prongs are in nostrils
- 18. Intranasal catheters • Flexible catheter with holes at distal 2 cms • FiO2 35-40% • Measured from nose to ear, lubricated and inserted to just above the uvula • Deep insertion can cause air swallowing and gastric distension • Must be repositioned every 8 hours to prevent breakdown • No advantages over nasal cannula
- 19. Simple masks • Made up of clear flexible plastic that can be moulded to fit patients face • Volume: 100-300 mL. • FiO2 40-60% at 6-10 L/min • Perforations, act as exhalation ports • Vents in the mask allow for the dilution of oxygen
- 20. Simple mask O2 inlet Exhalation ports • Open ports for exhaled gas • Air entrained through ports if O2 flow through does not meet peak insp flow • 35-55% O2 at 6-10 L/min
- 21. Simple masks • Indications: – Medium flow oxygen desired – mild to moderate respiratory distress – increased oxygen delivery for short period (<12 hrs) • Contraindications: – Poor respiratory efforts, apnea,severe hypoxia • Advantage: – Less expensive – Can be used in mouth breathers • Disadvantage – Uncomfortable – Require tight seal – Donot deliver high FiO2 – FiO2 varies with breathing efforts – Interfere with eating, drinking, communication – Difficult to keep in position for long – Skin breakdown
- 22. Simple masks Practical considerations: • Select a mask which best fits from the child's bridge of nose to the cleft of jaw, and adjust the nose clip and head strap to secure in place • No pressure point or damage to eyes • Flow <4 L/min results in rebreathing and carbon dioxide retention • The FiO2 inspired will vary depending on the patient's inspiratory flow, mask fit/size and patient's respiratory rate • Oxygen (via intact upper airway) via a simple face mask at flow rates of 4-6 L/min does not require humidification – Humidification may be indicated/appropriate for patients with secretions retention, or discomfort – Some conditions (eg. Asthma), the inhalation of dry gases can aggravate bronchoconstriction
- 23. Partial rebreathing face masks • Initial portion of the expired gases containing little or no CO2 (rich in oxygen) is collected in a reservoir while the remaining expiratory gases are vented to the atmosphere
- 24. Partial rebreather mask Exhalation ports O2 Reservoir • O2 directed into reservoir • Inspiration: draw gas from bag & entrains room air • Expiration: first 1/3 of exhaled gas goes into bag (dead space) • Dead space gas mixes with ‘new’ O2 going into bag • Delivers ~60% O2 Simple masks with additional reservoir that allows the accumulation of the oxygen enriched gas for rebreathing
- 25. Partial rebreathing face mask • Fio2 35-60 % • flow rates of 6 to 15 L/min • Flow rate must be sufficient to keep bag 1/3 to 1/2 inflated at all times • Minimum flow should be 6 L/min to avoid patient breathing large part of exhaled gases and to enable rest of exhaled air exit through vents
- 26. Partial re-breathing face mask • Indications: – Relatively high FiO2 requirement • Contraindications: – Poor respiratory efforts – apnea – severe hypoxia • Advantage: – Inspired gas not mixed with room air – Patient can breath room air through exhalation ports if oxygen supply gets interrupted • Disadvantage – More oxygen flow does not increase FiO2 – Interfere with eating and drinking
- 27. Non-rebreathing mask • Valve prevents exhaled gas flow into reservoir bag • Valve over exhalation ports prevents air entrainment • Delivers ~100% O2, if bag does not completely collapse during inhalation O2 Reservoir One-way valves
- 28. Reservoir Gas source Room air Expiratory gas To patient One way valves Non-rebreathing system
- 29. Non-rebreathing face masks • Oxygen flow into the mask is adjusted to prevent the collapse of the reservoir (12 L/min); prevents the room air from being entrained • Flow - 10-15 L/min • FiO2 - 90-100%
- 30. Non-rebreathing face mask • Indications: – High FiO2 requirement >40% • Contraindications: – Poor respiratory efforts – apnea • Advantage: – Highest possible FiO2 without intubation – Suitable for spontaneously breathing patients with severe hypoxia • Disadvantage – Require tight seal, Uncomfortable – Interfere with eating and drinking – Not suitable for long term use – Malfunction can cause CO2 buildup, suffocation
- 31. Non-rebreathing face masks Practical considerations: • To ensure the highest concentration of oxygen is delivered to the patient the reservoir bag needs to be inflated prior to placing on the patients face • Ensure the flow rate from the wall to the mask is adequate to maintain a fully inflated reservoir bag during the whole respiratory cycle • Do not use with humidification system as this can cause excessive 'rain out' in the reservoir bag • Flow rate must be sufficient to keep bag 1/3 to 1/2 inflated at all times • Avoid kinking and twisting of reservoir • Check that vales and rubber flaps are working
- 32. Venturi masks or Air-entrainment masks • A Venturi mask mixes oxygen with room air, creating high-flow enriched oxygen of a measurable concentration • It provides an accurate and constant FiO2 in range of 24-50%
- 33. Venturi mask or Air-entrainment mask • Dilutional masks • Work on Bernoulli principle • Oxygen is delivered through the jet nozzle, which increases its velocity • The high-velocity O2 entrains ambient air into the mask due to the viscous shearing forces between the gas traveling through the nozzle and the stagnant ambient air • FiO2 depends on – size of entrainment ports – nozzle – flow rate • The larger the port, the more room air is entrained and lower the FiO2 • Reliably provide 25-60% FiO2 at 4-15 L/min
- 34. 3: 24% 3: 26% 6: 28% 6: 30% 9: 35% 12: 40% 15: 50%
- 35. Venturi masks or Air-entrainment masks… • Indications: – Desire to deliver exact amount of FiO2 • Contraindications – Poor respiratory efforts, apnea, severe hypoxia • Advantage: – Fixed, reliable, and precise FiO2 – Does not dry mucus membranes – High flow comes from the air, saving the oxygen cost – Can be used for low FiO2 also – Helps in deciding whether the oxygen requirement is increasing or decreasing • Disadvantage – Uncomfortable – Cannot deliver high FiO2 – Interfere with eating and drinking
- 36. Venturi mask:Practical considerations • Oxygen must be humidified and warmed • Monitor FiO2 at flow rates ordered • Not effective for delivering FiO2 greater than 50% • To ensure that the patient's ventilatory requirements are met the total flow must exceed the patient's minute ventilation • To achieve the desired FiO2 use the diagram below
- 37. Oxygen hood • Small, clear plastic hood to cover infant’s head or head and upper torso • Patient more accessible without disturbing O2 delivery • For newborns and young infants • Correct size: That has enough room for baby’s head to fit comfortably and allow free neck and head movements without hurting baby • FiO2 80-90%, Flow 10-15 L/min
- 38. OXYGEN HOOD • 3-4 sizes are available • Too big: dilute the oxygen • Too small: discomfort and CO2 retention • Adequate flow of humidified oxygen ensures mixing of delivered gases and flushing out CO2 • Oxygen gradient can vary as 20%. Continuous flow >6 L/min avoids this problem • Ensure the headbox has a gap all around the child’s neck, this is important in preventing the accumulation and re-breathing of CO2 • Gas flow must be high enough to prevent re- breathing of CO2
- 39. Face tent/face shield • High flow soft plastic bucket • Well tolerated by children than face mask • 10-15 L/min, 40% FiO2 • Access for suctioning without need for interrupting oxygen
- 40. Oxygen tent • Clear plastic sheet that cover child’s upper body • FiO2~ 50% • Not reliable • Limit access to patient • Not useful in emergency situations
- 41. ,
- 42. Continuous positive airway pressure • By applying underwater expiratory resistance • Indicated – When oxygen requirement >60% with a PaO2 of <60 mmHg – Clinical parameters and general conditions also act as guiding criteria • CPAP reduce work of breathing, increases FRC and helps maintain it, recruit alveoli, increase static compliance, and improve ventilation perfusion ratio
- 43. Continuous positive airway pressure… • Methods: – Underwater (indigenous/bubble , commercial) – Ventilator • Used in – Early ARDS, acute bronchiolitis, pneumonia – It should be tried in spontaneously breathing child who does not require emergency intubation prior to conventional ventilation – Can be used in early, incipient or frank respiratory failure
- 44. Continuous positive airway pressure… • Humidification add to the cost • Water vapors condense in tubing – Block – Trickle into airways: collapse, pneumonia • Single tube may not be compatible (commercially available binasal prongs)
- 45. High flow nasal prongs • Humidified high flow nasal prong (cannula) oxygen therapy is a method for providing oxygen and continuous positive airway pressure (CPAP) to children with respiratory distress • HFNP may reduce need for NCPAP/intubation, or provide support post extubation • At high flow of 2 L/kg/min, using appropriate nasal prongs, a positive distending pressure of 4-8 cmH2O is achieved • This improves FRC and reduces work of breathing • Because flows used are high, humidification is necessary to avoid drying of respiratory secretions and for maintaining nasal cilia function • MOA: application of mild positive airway pressure and lung volume recruitment
- 46. High flow nasal prongs… Equipment • Oxygen and air source • Blender • Flow meter – <7Kg : standard 0-15L/min flow meter – >7Kg: high flow oxygen flow meter, 50L/min flow • Humidifier (Fisher and Paykel MR850) • Circuit tubing to attach to humidifier – Children <12.5kg: small volume circuit tubing – Children ≥12.5kg: adult oxygen therapy circuit tubing • Nasal cannula to attach to humidifier circuit tubing (size to fit nares comfortably) • Water bag for humidifier • Nasogastric tube
- 47. High flow nasal prongs • Indications – Respiratory distress from bronchiolitis, pneumonia, congestive heart failure – Respiratory support post extubation – Weaning therapy from CPAP or BIPAP – HFNP can be used if there is hypoxemia and signs of moderate to severe respiratory distress despite standard flow oxygen • Contraindications – Blocked nasal passages/choanal atresia – Trauma/surgery to nasopharynx • Complications – Gastric distension – Pressure areas – Pneumothorax
- 48. High flow nasal prongs Set up of equipment • Appropriate size nasal cannula and circuit tubing • Connect nasal cannula to adaptor on circuit tubing, and connect circuit tubing to humidifier • Attach air and oxygen hoses from blender to air and oxygen supply • Connect oxygen tubing from blender to humidifier • Attach water bag to humidifier and turn on to 37C
- 49. High flow nasal prongs Set up of equipment • Prongs should not totally occlude nares • Start the HFNP at the following settings: – Flow rate • ≤10Kg 2 L/kg/min • >10Kg 2 L/kg/min for the first 10kg + 0.5L/kg/min for each kg above that (max flow 50 L/min) • Start at 6L/min and increase up to goal flow rate over a few minutes to allow patient to adjust to high flow – FiO2 • Always use a blender, never use flow meter off wall delivering FiO2 100% • Start at 50-60% for bronchiolitis and respiratory distress
- 50. Hyperbaric oxygen • The goal is to deliver extremely high partial pressure of oxygen, >760 mmHg • Indications: – Smoke inhalation – CO poisoning – CN poisoning – Thermal burns – Air embolism – Clostridium myenecrosis – Osteomyelitis (refractory) – Compromised skin grafts – Radiation injury – Acute traumatic ischemia/acute crush injury – Severe decompression sickness – Necrotizing fasciitis • Requires specialized equipment and personnel with intensive care unit skills and knowledge of the physiology and risks unique to hyperbaric oxygen exposure (CNS and Pulmonary) • Cost, unavailability
- 51. Heliox • Heliox is a gas mixture of helium and oxygen: low density • Obstructive lung diseases (bronchiolitis, acute bronchial asthma) – In spontaneously breathing patients with asthma, heliox decreases PaCO2, increases peak flow, and decreases pulsus paradoxus – There may be benefit related to the combination of heliox with aerosol bronchodilator delivery in patients with acute asthma • Heliox reduce resistance with upper airway obstruction (post extubation stridor)
- 52. Heliox… • Care must be taken to administer heliox in a safe and effective manner • To avoid administration of a hypoxic gas mixture, it is recommended that 20% oxygen/80% helium is mixed with oxygen to provide the desired helium concentration and FIO2 • If an FIO2 requirement >40%, the limited concentration of helium is unlikely to produce clinical benefit • When using an oxygen-calibrated flow meter for heliox therapy, it must be remembered that the flow of heliox (80% helium and 20% oxygen) will be 1.8 times greater than the indicated flow
- 53. Heliox • For spontaneously breathing patients, heliox is administered by face mask with a reservoir bag • Y-piece attached to the mask allows concurrent delivery of aerosolized medications • Sufficient flow is required to minimize contamination of the heliox with ambient air: 12 to 15 L/min •Administration during mechanical ventilation can be problematic •Density, viscosity, and thermal conductivity of helium affect the delivered tidal volume and the measurement of exhaled tidal volume
- 54. Monitoring • Oxygen should not be administered without an objective assessment of its effect • Oxygen therapy should be used without wasting time and thought • Further therapy, amount, duration can then be formulated • FiO2 of 40-60% is adequate in most situations, 100% needed during resuscitation • Increasing requirement of FiO2 to maintain same SpO2 is an ominous sign • Children should be nursed in manner that makes them most comfortable • Mothers can be the best administrator of the oxygen • Spend some time to explain the situation
- 55. Monitoring… • Vital signs (hourly) – HR – RR (including level of distress) – BP – Temperature – SpO2 • Breathing pattern • Level of consciousness and responsiveness • Color • ABG SpO2 >92% and PaO2 > 60 mmHg are acceptable
- 56. Monitoring… • Check and document oxygen equipment set up at the commencement of each shift and with any change in patient condition • Hourly checks should be made for the following: – oxygen flow rate – patency of tubing – humidifier settings (if being used)
- 57. Monitoring… • Document – Day and time oxygen started – Method of delivery – Oxygen concentration and flow – Patient observation – Oronasal care and nursing plan • Oxygen is a drug and requires a medical order • Each episode of oxygen delivery should be ordered on the medication chart
- 58. Humidification • Humidification: Addition of heat and moisture to a gas • Rationale: – Cold, dry air increases heat and fluid loss – Air and oxygen have a drying effect on mucous membranes resulting in airway damage – Secretions can become thick & difficult to clear or cause airway obstruction – In some conditions e.g. asthma, the dry gases can cause bronchoconstriction • Indications: – Patients with thick copious secretions – Non-invasive and invasive ventilation – Nasal prong flow rates of greater than 2 L/min (<2 years) or 4 L/min (>2 years) – Facial mask flow rates of greater than 5 L/min – All high flow systems require humidification – Patients with tracheostomy
- 59. BAIN’S SYSTEM • Described by Bain & Spoerel in 1972 • Modification of Mapelson D system Inner tube inspiratory; outer tube expiratory+inspiratory • Length of tube: 1.8m • Outer tube diameter: 22mm • Inner tube diameter :7mm
- 61. Fresh Gas Flow (FGF) required: Spontaneous: 150 – 200 ml/kg/min Controlled : 70 ml/kg/min adult >60kgs 3.5 L/min for 10 – 50 kgs 2L/min for infants < 10kgs
- 62. ADVANTAGE: • Useful for pediatric as will as adult patient • Allows warming & humidification of gases • useful for spontaneous as will as controlled ventilation • Easily dismantled; sterilised; so useful in infected cases • Facilitates scavenging • Length of tubing is long so machine can be taken away from patient ; useful in head & neck & Neurosurgery. • Light weight • Can be used with ventilator DISADVANTAGE: • High fresh gas flow requirements • Cannot be used with intermittent flow machine. • Disconnection ,kink ,break, leak, at inner tube may go unnoticed – entire exhalation limb becomes dead space
- 63. AMBU BAG
- 64. Humidification… • Humidifier should always be placed at a level below the patient's head • Water levels of all humidifiers should be maintained as marked to ensure maximum humidity output • Condensation will occur in the tubing of heated humidifiers. This water should be discarded in a trash contain and never returned into the humidifier • Inspired gas temperature should be monitored continuously with an inline thermometer when using heated humidifiers • The thermometer should be as close to the patient as possible • Warm, moist areas such as those within heated humidifiers are breeding grounds for microorganisms (especially Pseumomonas) • The humidifier should be changed every 24 hours
- 65. Weaning • Depend on clinical and lab parameters • SpO2 is important • High flow and concentration should be gradually lowered while monitoring • Low flow and concentration can be continued without ill effects for long time
- 66. Adverse effects • Oxygen being combustible, fire hazard and tank explosion • Catheters and masks can cause injury to the nose and mouth • Dry and non-humidified gas can cause dryness and crusting • Long term oxygen therapy: proliferative and fibrotic changes lungs
- 67. Adverse effects… • CO2 Narcosis : – In patients with chronic respiratory insufficiency----hypercapnea – Respiratory centre relies on hypoxemia to maintain adequate ventilation – Oxygen supplementation can reduce their respiratory drive, causing respiratory depression and a further rise in PaCO2 resulting in increased CO2 levels in the blood – Monitoring of SpO2 or SaO2 informs of oxygenation only. Therefore, beware of the use of high FiO2 in the presence of reduced minute ventilation • Pulmonary Atelectasis/absorption atelectasis • Pulmonary oxygen toxicity : High concentrations of oxygen (>60%) may damage the alveolar membrane when inhaled for >48 hours • Retrolental fibroplasia: An alteration of the normal retinal vascular development, mainly affecting premature neonates (<32 weeks gestation or 1250g birthweight), visual impairment and blindness
- 68. Oxygen safety • Oxygen support combustion (rapid burning). Due to this the following rules should be followed: – Do not smoke in the vicinity of oxygen equipment – Do not use aerosol sprays in the same room as the oxygen equipment – Turn off oxygen immediately when not in use. Oxygen is heavier than air and will pool in fabric making the material more flammable. Therefore, never leave the nasal prongs or mask under or on bed coverings or cushions whilst the oxygen is being supplied – Do not use any petroleum products or petroleum byproducts e.g. petroleum jelly/Vaseline whilst using oxygen – Do not defibrillate someone when oxygen is free-flowing
- 69. Oxygen safety Oxygen cylinders should be secured safely to avoid injury and damage to regulator or valve • Do not store oxygen cylinders in hot place • Do not drag or roll cylinders • Do not carry a cylinder by the valve or regulator • Do not hold on to protective valve caps or guards when moving or lifting cylinders • Do not deface, alter or remove any labeling or markings on the oxygen cylinder • Do not attempt to mix gases in an oxygen cylinder or transfer oxygen from one cylinder to another
- 70. Take home message • Oxygen therapy saves life • The selection of an appropriate oxygen delivery system – Clinical condition – Patient's size and needs – Therapeutic goals • Risks and hazards – Advantages far outweighs the risks – Hypoxia more dangerous than correctly delivered oxygen • Humidification • Monitoring and proper documentation • Appropriate weaning