Manual Ventilation Flashcards
Functions of the Nose
- Humidify Air
- Transport Air
- Heating and Warming Air
- Sense of Olfactory
- Filter Air
External Nose
External Nares-There are two flared openings called alae
Vestibule-The most anterior portion of the nasal cavity before the alae
Anterior Nares-Located posterior to the vestibules are openings to the internal nose
Internal Nose
AKA nasal cavity
The nasal cavity extends from the anterior nares to the internal nares
The nasal cavity is tilted slightly downwards (10-15 degrees) from the front to the back
Epiglottis
Protects the airway by preventing food from entering
Little’s Area (Kiesselbach’s Plexus)
A highly vascular area located on the anterior aspect of the nasal septum in each nostril
Most nosebleeds will often originate from this area
Pharynx
A tube connecting the nasal cavity, mouth, larynx, and esophagus
Approximately 13 cm in length (in adults)
Extends from the base of the skull to the cricoid cartilage (at level of C)
Muscular wall is composed of skeletal muscle-This means that there is voluntary control which allows us to hold our breath
Nasopharynx
In theory it is a passage for air alone
Extends from the base of the skull to the uvula
Contains pharyngeal tonsils (adenoids) and tubal tonsils
5 Openings to Nasopharynx
The nasopharynx contains 5 openings which is important during intubation as we can have infection
These openings are
- 2 eustachian tubes
- 2 Internal nares
- 1 opening to the oropharynx
Oropharynx
Extends from tip of uvula to upper rim of the epiglottis
Common pathway for food and air
Contains palatine tonsils, which are commonly removed during tonsillectomy
Larynx
Conducts air into the lungs
Acts a switch mechanism to ensure that food bypasses the trachea and proceeds down the esophagus
Larynx is the most heavily sensory inervated organ in the body.
Stimulation of unaesthetized larynx causes very strong sympathetic response-HR and BP may double.
Phonation
True vocal cords located in larynx will vibrate as air passes between them through the glottis
Defenses in the Larynx
Pseudostratified ciliated columnar epithelial cell sit below the vocal cords and sweep mucus up into the pharynx continually
Larynx-Breath Hold, Effort closure and cough
Muscular vestibular folds (false vocal cords help to close the glottis tightly)
Valsalva Maneuver-performed by moderately forceful attempted exhalation against a closed airway, usually done by closing one’s mouth, pinching one’s nose shut while pressing out as if blowing up a balloon
Cartilage of the Larynx
There is 9 Cartilages of the Larynx
- 2 Arytenoid Cartilages
- 2 Cuneiform Cartilages
- 2 Corniculate Cartilages
- 1 Thyroid Cartilage
- 1 Cricoid Cartilage
- 1 Epiglottis Cartilage
Trachea
When we are intubating we want to go into the trachea we have to manipulate things because if we don’t manipulate things then the path of least resistance for intubation is through the esophagus
If doing an emergency cricoid cartilage you don’t have to go through the cric you can go through a ring that is not continuous but C shaped
Thyroid Cartilage
Thryroid cartilage forms anterior wall of larynx
Functions of the Trachea
- Conducts air in and out of the lungs
- Contraction of trachealis muscle can accelerate expired air to excel mucous during a cough
Trachea Measurements
Extends from the larynx to the main stem bronchi 12-15 cm in length and ~2 cm in diameter 16-20 C-shaped cartilage rings
Carina Topography
Carina sits behind “angle of Louis” anteriorly and level of T4 posteriorly
Patent Airway
Airway Patency is the state or quality of the airway being open, expanded, or unblocked
If you are bagging and not ventilating the patient reapply the mask and that is the most common cause
Loss of Airway Patency
Causes of loss of airway patency can be divided into 2 general categories
Central Causes-Any condition that leads to a depression of the CNS (i.e. <8)
Peripheral Causes-Airway obstruction caused by something originating outside the body
Jaw Thrust
The jaw thrust will move the tongue from the back of the throat
Central Causes-Decrease in Cardiac Output
Acute myocardial infarction (MI)
Cardiac tamponade-But when cause through a infection it is considered to be a peripheral cause
CHF
V fib or V tach
Hypovolemic Shock
Septic Shock
Massive Pulmonary Embolism
Mechanisms of Upper Airway Obstruction
Decrease in tone of submandibular muscles leads to posterior displacement of tongue against the posterior pharyngeal wall
While in a comatose state the position of the chin will worsen the obstruction
C-spine adopts a semi flexed position, narrowing the distance between the tongue and posterior pharyngeal wall
Epiglottis gravitates towards the larynx partially occluding the airway
Negative pressure cause by respiratory efforts in presence of obstruction draws tongue towards the airway
Peripheral Causes
- Peripheral causes come from outside of the body
- Infection
- Abscess
- Neoplastic (carcinomas)
- Physical and Chemical Agents
- Thermal
- Caustic Injuries- Can cause swelling
- Inhaled toxins
- Allergic/Idiopathic
- Traumatic
Signs of Loss of Airway Patency
Tachypnea and dyspnea
Noisy snoring respirations
Paradoxical breathing
Tracheal tug or retractions
Nasal flaring-Usually seen in babies
Expiratory Grunting-Is a compensation for collapse that is usually seen in babies
Cardiac dysrhythmias
Pressure in chest and low oxygen levels will affect the heart
Stridor
Absence of breath sounds or visible chest movement
Cyanosis
Peripheral Causes-Infection
Viral and bacterial infection laryngotracheobronchitis (e.g. croup)
Parapharyngeal and retropharyngeal abscess
Lingual tonsillitis
Hematomas or abscess of the tongue or floor of the mouth
Epiglottitis (also known as supraglottitis)
Similar to croup but the patient will have low energy and is very serious and in this case we do not manipulate the airway
Peripheral Causes-Neoplastic
Laryngeal carcinomas Hypopharyngeal and lingual (tongue) carcinomas
Peripheral Causes-Physical and Chemical Agents
Foreign bodies Chocking something shoved up a nose Thermal injuries-Can cause swelling Caustic Injuries- Can cause swelling Inhaled toxins
Peripheral Causes- Allergic/Idiopathic
Angiotensin converting enzymes inhibitors induced angioedema
Peripheral Causes- Traumatic
Blunt and penetrating neck and upper airway trauma
Central Causes of Loss of Airway Patency
When the CNS is depressed and comes from within the body
The causes of CNS depression varies
Most common cause of upper airway obstruction is the tongue
Includes-Decrease in cardiac output, TBI, Anesthesia, drug overdose, hypoxemia/hypercarbia, hypothermia/hyperthermia, metbolic derrangements
Central Causes-Hypoxemia/Hypercarbia
COPD, Asthma, ARDS, Pneumonia, moderate PEs
Central Causes-Metabolic Derangements
Hypo/hyperglycemia
hypo/hypernatremia
hypokalemia (lead to heart malfunction)
metabolic acidosis
hepatic encephalopathy
Signs of Loss of Airway Patency
Tachypnea and dyspnea
Noisy snoring respirations
Paradoxical breathing
Tracheal tug or retractions
Nasal flaring-Usually seen in babies
Expiratory Grunting-Is a compensation for collapse and usually seen in babies
Cardiac dysrhythmias-Pressure in chest and low oxygen levels will affect the heart
Stridor
Absence of breath sounds or visible chest movement
Cyanosis-Can be misleading due to polycythemia or hypothermia, will be check at the inside of the lips
Presentation of Obstructed Airway
Hot Potato Voice- Horse Voice
Difficultly in Swallowing Secretions
Drooling is a very serious sign
Dyspnea
STRIDOR-Means a complete obstruction is imminent
Cough
Stridor
High pitched inspiratory sound
Indicated that airway has already lost at least 50% of its usual caliber
Complete obstruction may be imminent
The volume and pitch are related to the velocity of air flow-Air flow is dependent on patient’s level of consciousness and inspiratory muscle strength
Often audible but may be detected early via auscultation over the trachea-Can normally be heard without a stethoscope
If it is epiglottitis don’t place the stethoscope near the throat just keep them calm
Establishing and Maintaining Patient Airways Manuevers
Head-tilt/ Chin-Lift
Jaw Thrust Maneuver
Occasionally opening the airway is all that is require to re-establish the airway
Head-Tilt/ Chin-Lift
Used when no c-spine injury is evident
Performed with patient on his back and unconscious
Place palm across patient forehead, and firmly tilt head backwards. Fingers of other hand placed under ye bony part of lower jaw to bring chin forward and teeth almost to occlusion
Supports jaw and helps tilt head back
Mouth should not be completely closed, and rather should be slightly open
This maneuver elevates the tongue off the posterior pharyngeal wall, hopefully relieving obstruction
If fingers press too deeply into the soft tissue under chin, may obstruct airway by oving the tongue
If dentures are not too loose the head tilt chin lift with make the mouth to mouth seal easier. If denture can not be kept in placed though they must be removed
Babies have a large occiput and when putting them in this position make sure to not do the full chin lift but rather put them in the sniffing position
The Jaw Thrust
The jaw thrust is the safest initial approach to opening the airway with suspected neck injury as it is accomplished without extending the neck. The head is supported without tilting it backwards or tuning it side to side
Used to accomplish the forward displacement of mandible
Grasp the angle of the patient lower jaw and lifting with both hands, one on each side, displace mandible forward while titling the head backwards
This will elevate the tongue and hopefully relieve the obstruction
If the lips are closed, retract the lower lip with thumb
Patient is Breathing but Airway is Obstructed What To Do?
Use a PHARYNGEAL AIRWAYS
PHARYNGEAL AIRWAYS
Devices used to elevate the tongue off the posterior pharyngeal wall and away from the hard and soft palates, thereby establishing a patent airway through which spontaneous ventilation can be achieved
Breath stacking will occur when you do not fully allow them to exhale
Oropharyngeal Airways (OPAs)
Rigid, curved devices with an air passage, placed through the mouth with the end resting distal to the tongue above the glottis opening
Oropharyngeal Airways (OPAs) Indication for Use
- Used in patients with decreased submandibular tone
- Obtunded 2 degrees to any of the central cause of airway obstruction
- Anesthesia
- Deep sedation
- Used when manually ventilating a patient
- Used as aid for deep suctioning
- Used as a bite block
- Some model used to facilitate intubation
OPA Contraindications for Use
Patients with obvious oral trauma
Awake or semi-conscious patients
May cause vomiting or gagging
IMPORTANT-If a patent is awake enough to spit or tongue the device out then they are too awake for the device to be used
OPA Sizing
Proper sizing
Place the airway next to the face with the flange at the mouth and the tip of the airway should reach the angle of the jaw (tragus of the ear)
Complications of OPA
May cause trauma to the lips, mouth, or teeth-Rare
May cause pressure necrosis
Difficult to perform mouth care
May cause gagging and vomiting-May push the tongue back
Nasopharyngeal Airways (NPAs)
AKA nasal trumpet
Soft or semi-rigid hollow tube placed through the nares, the tip lying distal to the tongue above the glottic opening
May be sized in mm I.D. or French sizes
NPA Indications for Use
- Semi-awake patients who require some airway maintenance and do not tolerate the OPA
- Ay be used when insertion of OPA is difficult or contraindicated
- Maybe used to facilitate deep suctioning
- Pierre-Robin Syndrome (in neonates)
- Micrognathia-Tiny Chin
- Mandibular hypoplasia
Contraindications of NPA
Obvious nasal trauma
Deformities of the nose
Basal fractures of the nose (Racoon eyes and battle sign)-This may indicate skull fractur but use history to help determine
Coagulation disorder-NPA can cause nosebleeds
Complication from Use of NPA
If too long can enter into the esophagus causing gastric distension and hypoventilation
May cause vomiting and laryngospasm (big issue with infection) in semi-conscious patient
Injury of nasal mucous with bleeding
Sinusitis
Bypassing natural defenses
Otitis Media (ear infection)
Intubation of meninges (basal skull fracture)
Occlusion of airway by secretions
Tissue necrosis
Resuscitator
Used when pt. is not breathing on their own
Manual Resuscitator
Bag-Valve-Mask (BVM)
Bag-Mask Ventilator (BMV)
“Bagger”
“Portable handheld devices that provide a means of delivering positive pressure to a patient’s airway”
“Deliver room air (R/A), oxygen air-oxygen mixtures via a mask or through an adapter that attaché directly to a patients ET”
You will know you are giving enough air if there is chest rise
Manual Resuscitator
Hand squeezing a bag provides the mechanical force necessary to generate a positive pressure
Requires an oxygen source to deliver FiO2 greater than 0.21
In the baby and child versions they will have pop off valves
Commonalities in Bag
- Universal connector (15/22 mm)
- This allows them all to be connected to trachs
- Requires an O2 sources for FiO2 >0.21
- Oxygen flow meter
- 50 psi source
- Wall outlet
- Cylinder
- Originally designed for use during CPR
Self Inflating Manual Resuscitator
Does not require a compressed gas source for operation
Re-usable or disposable
Self Infalting Resuscitator Parts
- Self –inflating bag
- (volume depends on patient population)
- Air inlet/Oxygen Reservoir attachment site
- Oxygen Inlet
- Patient Outlet
- Valve assembly
- One way, non-rebreathing
- Oxygen reservoir (required for high FiO2)
- Pressure release (pop-off) valve (optional)
- Pressure Gauge / Guage attachment site (optional)
Classess of Non-Rebreathing Valves
- Spring-Loaded
- Diaphragm
- Duckbill (most common)
- Leaf-type
- Fishmouth
Pneumatic Resuscitators
- Used when unable to bag
- Commonalities
- Universal connector (15/22 mm)
- This allows them all to be connected to trachs
- Requires an O2 sources for FiO2 >0.21
- Oxygen flow meter
- 50 psi source
- Wall outlet
- Cylinder
Safety Mechanisms of Resuscitators
- Non-Rebreathing Valve (Self-Inflating)
- Prevents rebreathing of exhaled gases
- High Pressure Pop-Off Valves (self-Inflating)
- Prevents delivery of overly high pressure to patient (infant and children only)
- Maximum circuit pressure control (T-Piece Resuscitator)
- Will take away the variability of the pressure delivered in a breath
- Standard 15/22 mm connectors
- Allows for easy connection and disconnection
Quality Control Mechanisms
- Operation manual should specify
- BVM device underwent safety and standard testing
- Criteria was met
Stamdard Construction for Resuscitators
- Resuscitators capable of delivering FiO2 > or = 0.95
- Must be able to operate at-Extreme temperatures and Relative humidity 40-96%
- Deliver Vt > or equal to 600 ml into test lung for adult baggers
- With compliance of 0.2L/cmH2O
- With resistance of 20 cmH2O/L/sec
- Non-rebreathing valve withstand oxygen flow rate up to 30lpm
- If valve malfunctions due to foreign obstruction (e.g. vomitus), must be restored within 20 seconds
- Must have standard 15/22 mm connectors
- Adult resuscitators not have pressure limiting system
- Resuscitators for infants and children have pressure relief valve that limits PIP to:
- 40 +/- 10 cmH2O for children
- 30 +/- 5 cmH2O for infants
- When incorporating pressure limiting system, override capability must exist and must be apparent to operator
- Resuscitator able to operate after being dropped from height of 1 meter on to concrete floor
- Easily disassembled for sterilization and disinfection purposes
- Should not be possible to accidentally interchange parts
- making unit malfunction
- not function at all
Mask Seal
Hand Positioning-Single Hand
Lift chin up to the mask
Proper Ventilation
Connect bag to mask and O2
Should not use entire volume of bag
Assess for mask seal
Should feel some resistance in the bag.
Does the chest rise?
Can you hear a leak?
Steps to improve mask seal
Remove mask and reseat to face
Is airway patent
Head tilt chin lift?
OPA
Suction oropharynx
Two hand mask seal
Reinserting patient’s false teeth
Assessment of effective ventilation.
Goal is for visible chest rise
Chest rise and fall with ventilation
Breath sounds with ventilation
Improving SpO2
Capnograph waveform-end tidal CO2 (confirmation of intubation and can tell us about effectiveness of CPR by seeing if you are pumping enough blood through the body)
Ventilating the Patient
- 12 breaths per minute
- Every 5 seconds
- Target 500-600 mls for an adult
- Ti 1.0s
- Decrease insufflation of stomach with gentle ventilation
- Esophageal sphincter opening pressures ~25cmH2O
BMV Golden Rules
Manual ventilation skill with proper equipment is a fundamental premise of advanced airway management
Anybody (almost) can be oxygenated and ventilated with a bag and a mask
The art of bagging should be mastered before the art of intubation
What Will Make Resuscitation Difficult
M.O.A.N.S.
-
M- Mask Seal
- Bushy beards, trauma
-
O- Obesity/Obstruction
- ↑ weight of chest, ↓ diaphragmatic excursion
- ↑ Resistance 2° to swelling, adipose tissue
-
A- Age
- Older than age 55 (not a hard,fast rule)
-
N- No Teeth
- Face tends to cave in
-
S- Stiff, Snoring Hx
- Lungs resistant to ventilation (asthma, COPD)
Describe three major hazards associated with manual resuscitation. Which is the most common?
- Delivery of excessive high airway pressure (most common)
- Common in intubated patients
- Defective nonrebreathing valve
- Can cause an inspiratory leak and tidal volume escaping through the exhalation port and not delivered to the patient
- Faulty pressure-relief valves
- Can cause gas delivery at excessively high pressures and increases the risk of barotrauma
- What is the difference between tracheotomy and tracheostomy?
A tracheostomy is a surgically created hole at the front of the neck into the trachea. The procedure of creating this hole and placing a tube within it (through which the patient breathes) is called a tracheotomy.
List factors considered when determining whether the patient should have a tracheotomy/tracheostomy.
Indications of a tracheotomy include:
- Upper airway obstruction or trauma
- Continuing need for artificial airway after a prolonged period of oro/nasotracheal intubation
- To facilitate removal of secretions from tracheobronchial tree when patient is unable to raise secretions
- Inability to wean from artificial airway even after being weaned off of mechanical ventilation
- Long term care patients with neuromuscular disease
- Obstructive sleep apnea
Briefly describe the two main methods of tracheotomy.
Cricothyroidotomy is a surgical incision to the trachea which passes through the cricothyroid membrane and results in the insertion of an endotracheal tube or a tracheostomy tube. Under this method, a single horizontal incision is done through the skin to the trachea.
Percutaneous dilatory tracheostomy (PDT) is the more common method of tracheotomy due to its effectiveness, simplicity, and low incidence of complications. This method is performed mostly in the ICU if the patient is in the unit and intubated for more than 7 days. PDT is performed mostly with the Ciaglia method: a guide wire is placed between the first and second or second and third tracheal rings and plastic dialators is pushed through the soft tissue until the appropriate size is met. This method is usually aided with the use of a bronchoscopy.
Describe the four mechanisms of airway emergencies in patients with artificial airways and how to troubleshoot these situations. Which mechanism is the most common?
DOPE:
Displacement: Reposition (if possible) or remove tube and bag until reintubation is possible.
Obstruction: (Most Common!) Many different causes, but move patient’s head/neck to reposition, deflate cuff, suction catheter through tube, or flush tube with saline or mucus shaving device
Pressure: The pressure of the cuff on the ETT can cause issues if under-inflated or over-inflated. If under-inflated, air and secretions can leak around the cuff and cause ventilation issues. Over-inflation can cause the trachea to become inflamed and cause further ventilatory issues.
Equipment: Anything that causes a stoppage in the flow of oxygen to the patient. Check the tubing or vent to see if any kinks have developed, and have back-ups. You can also remove tube and bag patient until they can be reintubated.
Humidification and Warming Provided by the Mouth
The mucosal cavity of the mouth will provide humidification and warming of inspired air
Much less efficient than nose
Laryngopharynx
A passage way from the epiglottis of the esophagus to cricoid cartilage (C6)
Transport of Air
Most of air moved through the respiratory tract during respiratory breathing enters through the nares and nasal cavity
Mouth breathing will be used during things like exercise to reduce resistance at higher ventilation rates
Function of Corniculate and Cuneiform Cartilage
The corniculate and cuneiform cartilage function to support the soft tissue on either side of the vocal cords
Cricoid Cartilage
- Cricoid Cartilage- only laryngeal structure that forms a complete ring of cartilage around the airway and the narrowest region of the upper airway in infants
- The cricothyroid ligament is occasionally used as the location for placement of a emergency placement for an artificial airway
