Techniques of Oxygen Delivery

Dr. Sunil Agrawal1st yr MD Pediatrics

Contents

• Requirement of supplemental oxygen• Different types of flow systems• Devices used for oxygen delivery• Technique to delivery oxygen• Adjuncts to Oxygen Delivery• Summary • References

• Patient conditions that warrant administration of Supplemental oxygen:– Difficulty breathing– Respiratory compromise due to any cause– Circulatory compromise– Shock– Decreased level of consciousness– SpO2 of less then 96%

• Oxygen delivery system can be divided into – Low flow systems– High flow systems

Low Flow System

• In this the room air is entrained because the gas flow is insufficient to meet all inspiratory flow requirements.

• Provide an oxygen concentration of 23% to 90 %• Not so reliable

High Flow Systems

• The flow rate and reservoir capacity provide adequate gas flow to meet the total inspired flow requirements of the patient.

• Entrainedment of the room air does not occur.• Provide low or high inspired oxygen

concentration.• Reliable

Low Flow Systems

Oxygen mask

• Simple oxygen mask- – low flow device– Deliver 35% to 60% oxygen with flow rate of 6 to 10 L/ min– Minimum oxygen flow of 6L/min should be used– Indications: Medium flow O2 desired- mild to mod. Resp

distress– Contra indication: Poor resp. effort, Severe hypoxia, Apnea– Advantage: less expensive– Disadvantage : does not deliver high conc. O2 , Interferes

with eating and talking.

• Partial rebreathing mask– Simple face mask + reservoir bag– Reliable to provide oxygen concentration of 50% to

60 %– Oxygen flow of 10 to 12 L/min is generally required– Indications: relatively high O2 requirement .– Contra indication: Poor resp. effort, Severe hypoxia, Apnea– Advantage: inspired gas not mixed with room air– Disadvantage : more O2 flow does not increase O2 conc,

Interferes with eating and talking.

• Non breathing mask– Face mask + reservoir bag+

• A valve incorporated into the exhalation port • A valve placed between reservoir bag and mask

– Oxygen flow into the mask is adjusted to prevent collapse of bag– Inspired concentration of oxygen of 95% can be achieved by 10 to

12L/min of oxygen– Well sealed face mask is used– Indications: delivery of high conc. Of O2

– Contra indication: Poor resp. effort, Apnea– Advantage: high conc. O2 without intubation

– Disadvantage : expensive, more O2 required. Interferes with eating and talking. Requires a tight seal.

• Venturi- type mask– Reliable– Provide controlled low to moderate (25% to 60%) of

inspired oxygen concentration– Indications: desire to deliver exact amount of O2

– Contra indication: Poor resp. effort, Severe hypoxia, Apnea

– Advantage: fine control of FIO2 at a constant flow

– Disadvantage : expensive, can not deliver high O2 conc. Interferes with eating and talking

Face tent

• Also known as face shield• High flow soft plastic bucket• Well tolerated by children then face mask• Up to 40% of oxygen can be delivered with 10

to 15 L/min of oxygen flow• Access for suctioning is achieved without

interrupting the oxygen flow.

Oxygen tent

• Clear plastic shell that encloses the child’s upper body

• Provide more then 50% of O2

• Not reliable• Limits access to patient• Cannot be used in emergency situation.

Nasal Cannula

• Low flow oxygen device• Consist of 2 short soft plastic prongs which are inserted in

to the ant. Nares and O2 is delivered into the nasopharynx

• Upto 4 L/min of O2 can be used• Does not provide humidified oxygen

– Indications: low to mod O2 required, mild or no distress, long term O2 therapy requirement.

– Contra indication: Poor resp. effort, Apnea, severe hypoxia, mouth breathing.

– Advantage: comfortable, well tolerated.– Disadvantage : does not deliver high O2 conc.

Nasal catheter

• Flexible, lubricated oxygen catheter with multiple holes in distal 2 cm

• Advanced posteriorly into the pharynx through nostril

• No advantage over nasal cannula• Hemorrhage and gastric distension can occur

High Flow Systems

Oxygen hood

• Clear plastic shell with covers the patient’s head• Well tolerated by infants• Allows access to chest, trunk and extremities• Permits control of inspired oxygen

concentration, temp. and humidity• Flow of oxygen- 10-15 L/min• 80 to 90 % of oxygen conc. can be achieved • Can be used in neonates and infants only.

Bag Valve Mask Ventilation

• Two hands must be used– One hand- head tilt- chin lift maneuver– Other hand- compress ventilation bag

• In infants and toddlers, the jaw is supported with base of middle and ring finger. Pressure in submental area should be avoided

• In older children finger tips of 3rd, 4th, 5th fingers are placed on the ramus of mandible to hold the jaw forward and extend head.

• A neutral sniffing position is maintained.• Hyperextension of head is avoided to maintain the

optimum position for airway patency.• This can be achieved by placing folded towel under

the neck and head.• Distention of stomach frequently occurs. It should

be avoided or treated promptly to prevent aspiration. It can be minimized in unconscious patient by applying cricoid pressure (Sellick maneuver)

Self inflating Bag-Valve Ventilation Devices

• At oxygen inflow of 10L/min, pediatric self inflating bag provides 30-80% of oxygen without oxygen reservoir and 60-95% with reservoir.

• 10-15L/min of oxygen is required to keep the adequate amount of oxygen in reservoir.

• Before initiating ventilation oxygen flowing into the bag should be confirmed.

• Many bags have a pop off valve set as 35 to 45 cm of H2O to prevent barotrauma.

• During CPR a high pressure is required so pop off valve should be closed.

• Administered tidal volume should be approx. 10-15 ml/kg.

• About 450ml of bag should be used for ventilating full term neonate or infant.

• When larger bags are used , only the force and tidal volume necessary to produce effective chest expansion should be used.

• Bag with fish mouth or leaf flap operated valve should not be used to provide supplemental oxygen during spontaneous respiration.

Anesthesia Ventilation System

• Consist of reservoir bag, an overflow port, fresh gas port and standard connector for mask or ET tube

• For infant- 500ml; for children- 1000 to 2000ml; for adult- 3000-5000ml is reqd.

• More experience is reqd. to use• Fresh gas flow should be

• <10 kg= 2l/min• 10-50 kg= 4L/min• >50 kg= 6L/min

• Risk of barotrauma and hypercarbia is more• Effective ventilation is determined by adequate chest

movement.• PEEP or CPAP can be provided by adjusting pop off valve.

Endotracheal Airway

• Most effective and reliable method of assisted ventilation because:– The airway is isolated, ensuring adequate

ventilation and O2 delivery– Reduces aspiration chance– Interposition of ventilations with chest

compressions can be accomplished efficiently.– Insp. Time and PIP can be controlled– PEEP can be delivered.

Indications for Intubation

• Inadequate CNS control of ventilation• Functional or anatomic airway obstruction• Loss of protective airway reflexes• Excessive work of breathing• Need of high PIP or PEEP• Need of MV support• Potential occurrence of any of the above if

patient is transported

Endotracheal Tube

• A cuffed ET tube is generally indicated for children aged 8-10 yrs or older.

• In younger children normal anatomic narrowing at the level of cricroid cartilage provides a functional cuff.

• ET tube size= age/4 + 4; length= age/2 +12 or depth of insertion= tube size*3

• ET tube 0.5 mm smaller and larger should be readily available.

Adjuncts to Oxygen Delivery

Oropharyngeal Airway

• Flange + Bite block Segment+ curved body• Curved body is designed to fit over the back of

tongue to hold it and soft hypophalengeal structures away from post. Pharyngeal wall.

• Indicated in in unconscious pt. if procedure to open airway fail to provide and maintain a clear, unobstructed airway.

• Size: corner of mouth to angle of jaw

• Oropharyngeal airway should be inserted by using the tongue depressor or

• The airway can be inverted for insertion into the mouth , using the curved portion as depressor. As the airway approaches the back of oropharynx , it is rotated 180° into proper position.

Nasopharyengeal Airway

• Soft rubber or plastic tube that provide airflow between nares and posterior pharyngeal wall

• Shortened ET tube can also be used• Responsive pt. can tolerate well.• Length= tip of the nose to tragus of the ear• The airway is lubricated and inserted through the nostril in a

posterior direction perpendicular to the plane of the face and passed gently along the floor of nasopharynx.

• Patency must be frequently evaluated• Too long size may irritate vagus nerve, epiglottis or vocal

cords and stimulate cough, vomit or laryangospasm.

Summary

• Low flow systems are:– Face mask-

– Simple Face Mask– Partial rebreathing Mask– Venturi Mask

– Face tent– Oxygen tent– Nasal Cannula

• High Flow Systems– Non Rebreathing Mask– Oxygen Hood– Bag Valve Mask Ventilation– Endotracheal Airway

• Proper device should be selected according to the patient’s need.

• Proper size of device should be used for effective oxygen delivery.

References

• Pediatric Advance Life Support• Paramedic: Airway Management 2011• Pediatric Critical Care Medicine: Basic Science

And Clinical Evidence edited by Derek S. Wheeler, Hector R. Wong, Thomas P. Shanley

Thank You