AMBU BAG AND NON RE - BREATHING VALVES.pptx

Ambubag and non rebreathing vavlves f anaesthesia

1. AMBU BAG AND NON RE - BREATHING VALVES PRESENTED BY : DR. S.SHREEJA MODERATED BY : DR. PALLAVI MAM ( FACULTY ANAESTHESIA )

2. AMBU BAG: Artificial Mandatory Breathing Unit or Air Mask Bag Unit Ambu Resuscitator is a black coloured self inflating double ended with foam rubber lining . It is available in two sizes it has an ambuE2 non breathing valve containing bobbin ,disc, spring ,steel ball ,air inlet valve and oxygen inlet connection with or without attached oxygen reservoir

3. DEFINITION: A bag valve mask sometimes referred to an AMBU bag is a handheld tool that is used to deliver positive pressure ventilation to any subject with insufficient or ineffective breaths. INDICATIONS TO USE AMBU BAG: Respiratory failure Respiratory arrest In case of ventilator failure Transfer of critical patients between wards In between suctions

4. CONTRAINDICATIONS TO USE AMBU: Upper airway obstruction (Absolute Contra indication) Paralysis and induction(Risk of aspiration) OTHER NAMES OF AMBU BAG: Manual resuscitator Self inflating bag

5. TYPES: Reusable - available in every clinic and ambulance Disposable - It is used in case of emergency requiring urgent departure. For infants and children up to 10KG For paediatric patients weighing 10 to 40 kg Adult for people weighing more than 40KG

6. ADULT,PAEDIATRIC AND INFANT AMBU BAG

7. Ideal capacity of a bag for a neonate is 240 to 750 ml. For a baby less than 1500 gm use a bag of 240ML to 350ML capacity TECHNIQUE TO USE: Sniffing position if C Spine is ok. Thumb plus index finger to maintain face seal Middle finger under mandibular symphysis Ring and little finger under the angle of mandible

8. COMPLICATIONS: Aspiration Hypoventilation Hyperventilation pneumothorax hyperventilation with ambubag may lead to barotrauma causing lethal complication of pneumothorax {4 to 15% }chances

9. NON RE BREATHING VALVES – Non rebreathing valves ensure unidirectional flow of gases. During inspiration gases flow exclusively into the patient port, while during exhalation they went out through the expiratory port And VALVE TERMINOLOGY : valve body assembly: It is the housing with associated internal parts valve body: It is the housing for valve body assembly Valve seat or seating: It is the surface with a partially or completely obstructed opening Valve Inlet: Fresh gas enters the valve through the inlet and is usually a 22 mm connecion

10. Various types of Non Rebreathing valves: POSITIONAL : This type of non rebreathing valve must remain horizontal as it requires gravity to close it completely. NON POSITIONAL: it is closed by elastic tension of rubber or by spring FLAP: It has a movable part made of flexible material and is secured at its centre or at its edge FISH MOUTH : it is a special type of flap valve in which two flaps approximate at midpoint DISK: It has a movable part that is flat and made of plastic or metal. held on its seat by gravity or spring disc MUSHROOM: It has a hollow balloon like structure that occludes the opening when inflated. RELIEF VALVE : it is an optional valve but recommended to vent the excess gas to atmosphere

11. CLASSIFICATION : Depending on the type of respiratory function The patient exerts a negative pressure which is transmitted to the inside of the valve during spontaneous ventilation , however during controlled respiration a positive pressure exists inside the valve during inspiration. Valves designed for spontaneous respiration: ex. Stephens slater valve: During inspiration the negative pressure exerted by the patient closes the exhalation port. During exhalation the pressure in the valve increases and the gas escapes through the exhalation port . If this valve is to be used for controlled ventilation it is essential to close the exhalation port with a finger during inspiration.

12. Valves designed for controlled respiration: Artificial mandatory breathing unit (AMBU) Resuscitation valve : - In this type of valve a rise in pressure opens the inlet and close the exhalation port. -If the patient is allowed to breathe spontaneously room air through the exhalation port will be inspired -Hence it cannot be useful for general anaesthesia

13. Valves designed for both spontaneous and controlled ventilation: Ruben valve, Ambu E, Lewis leigh valve These can be used for both spontaneous and controlled ventilation. The exhalation port is closed and the inlet opens during inspiration with either controlled or spontaneous respirations. Only dual purpose valves are used during anaesthesia.

14. DEPENDING ON THE POSITION: Positional valve: It works on gravity Non positional valve: it is not dependent on any position. example: flap valve, fish mouth valve, disc type valve. AGA – POLY – VALVE : It is used with Sanjeevani Manual Resuscitation bag for giving general anaesthesia. It has inspiratory limb expiratory limb patient and vaporiser end It has a dead space of about 7-8 ML and has low resistance It is available as simple poly valve to be used with ventilator and revivator valve with oxygen attachment

15. AMBU E, AMBU HESSE and AMBU E2 can be used as dual purpose valves. AMBU VALVE : It is available in various variants and is used for controlled ventilation. It is commonly used with amburesuscitation bag It is made of metal or plastic material, It has a movable yellow plastic disc that is held in place by a spring. A locating pin centres the disc When the Ambu resuscitation bag is squeezed the force of gas pushes the disc to close the exhalation port thus allowing the inhalation. During exhalation the pressure on the inlet side of the disc falls and the spring pushes the disc to close the inlet thereby allowing the exhaled gases to pass through the exhalation port. During spontaneous ventilation the interior of disc does not move and the patient inhales atmospheric air. When reassembling it after disassembling for cleaning the guide pin must be inserted through the appropriate channel

16. AMBU E VALVE : The unidirectional flow of gases is controlled by two labial flap valves 1 each for inhalation and Exhalation. It can be used for both spontaneous and controlled respiration It is made up of transparent plastic the inlet end is blue coloured During spontaneous respiration the negative pressure during inspiration closes the valve at the expiratory port and the fresh gases flow in through the inspiratory port. During expiration the valve at the inspiratory port closes and the valve at the expiratory port opens so as to allow the expired gases to be vented to the atmosphere. The valve at the expiratory port prevents inhalation of the downstream gases during spontaneous ventilation.

17. When Ambu E is used for controlled ventilation higher amount of gases are required to produce a complete expiratory seal If the flows are not high the seal may be incomplete allowing some of the inspiratory gas to pass right across the wall hence low tidal volumes are delivered. It has a dead space of 10 ml.it cannot be used with resuscitators that do not produce initial high surge of gas required to produce an effective seal.

18. AMBU E2 VALVE : It contains single unidirectional valve with no valve at the expiratory end. It can be used for spontaneous and controlled respiration The negative pressure created by the patient during spontaneous inspiration opens the inspiratory port. It also draws air from the expiratory port the result is that a mixture of fresh gas and air is inhaled. During controlled respiration the positive pressure from back the expiratory port is occluded by inspiratory wolves so that fresh gases pass to the patient. During expiration the inspiratory port closes and Exhaled gases pass through the expiratory port to the atmosphere it has a dead space of 10 ml.

19. AMBU HESSE VALVE: It is similar to Ambu E wall but slightly larger in size. It can be used for both spontaneous and controlled respiration. It has an inspiratory leaf and inspiratory relief and a mushroom valve. When used for controlled ventilation small increase in pressure within the self inflating bag due to manual compression expands the elastic mushroom valve that completely occludes the expiratory port. Further compression of the bag opens the inspiratory leaf while forcing gas from the bag into the inspiratory port thus providing inspiratory flow At the beginning of exhalation phase the self inflating bag starts to re expand The reduced pressure within causes the mushroom wall to collapse and the inspiratory leaf valve to close sealing the bag off from the main valve. The exhaled gases then leave the system through the expiratory port via the expiratory leaf valve.

20. IDEAL NON RE BREATHING VALVE : It should have minimal dead space, minimal resistance ,no forward or backward leak ,lightweight, transparent, easy to clean ,sterilise . non noisy ,non sticky ,compact and inexpensive with minimal opening pressure. Non rebreathing walls prevent rebreathing the inspired concentration of gases and vapours can be controlled as there is no mixing it helps in dissipation of heat and water vapour it can be used for spontaneous and controlled respiration they are compact lightweight and mobile with minimal dead space however as large flows are needed there is wastage of gases and loss of heat and humidity from the patient it also leads to theatre pollution

21. THANK YOU NEXT PRESENTATION : DR SWETA , JOURNAL CLUB MODERATOR : DR ABHINAV SIR, FACULTY ANAESTHESIA References : text book of Baheti and Dorsch and Dorsch