Mechanical Ventilation lectutre Flashcards
Tidal volume (vt)
amount of air inhaled and exhaled
Inspiratory Reserve volume (IRS)
maximum air inhaled over tidal volume
Expiratory Reserve Volume (ERV)
max amount of air exhaled over Tidal volume
Residual volume (RV)
amount of air left in lung after exhale
Functional Residual Capacity
SUM of ERV and Vt
Oropharyngeal Airway:
-location
- follows natural curvature of the tongue
- holds tongue away from throat to maintain patency
Oropharyngeal Airway:
-what types of patient to use it on
UNCONSCIOUS patient who has an absent or diminished gag reflex
Oropharyngeal Airway:
-what are the benefits? complications that it avoids?
Avoids the risk of nasal irritation and sinitus
Nasopharyngeal Airway:
-location
- inserted into one nare
- maintains patency of hypopharynx
Nasopharyngeal Airway:
- what does it limit the stimulation of?
gag reflex
Tracheostomy:
-what type of patients to use it on?
-LONG TERM MANAGEMENT: 7-10 days
Tracheostomy:
-advantages of having a trach for the patient
- more comfortable for the patient
- patient can eat and talk
- easier to remove secretions
- reduces decannulation
Tracheostomy:
-two ways to insert the trach
1) OR surgical
2) percutaneous procedure- bedside
Tracheostomy:
-two items to have at the bedside for safety
- obturator
- 2nd trach + a smaller size for accidental dislodgement
- vaseline gauze
Tracheostomy:
-complications during insertion
- misplacing the tube
- hemorrhage
- laryngeal nerve injury
- pneumothorax
- cardiac arrest
Tracheostomy:
-complications in management
- stomal infection
- hemorrhage
- fistula
- tube obstruction and displacement
- *SKIN BREAKDOWN!
Tracheostomy:
-complications with removal
- days to weeks after:
- stenosis and fistulas
Tracheostomy:
-when should sutures be removed?
-only in there for 7-10 days
Endotracheal Tubes:
-location
- insertion into the trachea via the nose or mouth
Endotracheal tubes:
-what type of patients to use it on
SHORT TERM management
Endotracheal Tube:
-Indications for use
- protection from aspiration
- application of positive pressure ventiation
- high oxygen concentrations
Endotracheal Tube:
-what happens if the air-filled cuff deflates?
-risk for aspiration pneumonia
Endotracheal Tubes:
-advantages of use for healthcare professionals
First.
Fast.
Easiest
Endotracheal Tubes:
- complications
- ORAL TRAUMA: broken teeth
- vomiting with aspiration
- hypoxemia
standard intubation equipment
- laryngoscope
- oral Endotracheal tube with various sizes
- ambu-bag and O2
- suction equip
- paralytic meds
- cap CO2 detector- turns purple to yellow
Rapid Sequence Intubation
-7 steps
(1-4)
1) preperation
2) Pre-oxygenate for 3-5 min with 100%
3) Pretreatment within 3 min of next step
4) give paralytics and sedatives
Rapid Sequence Intubation (RSI)
1) paralytics
2) sedatives
1) succinylcholine and rocuronium
2) Versed, ketamine
Rapid Sequence Intubation (RSI)
-step 5
5) Protection and Positioning
- Sniff position
- Sellick maneuver (cricoid pressure) - BURP
RSI:
- Sniff position
- Cricoid pressure
- tilt back with neck hyperextended
- BURP: back, up, right, pressure on trachea
- closes off risk for aspiration
Rapid Sequence Intubation (RSI):
-stepts 6-7
6) Placement of ETT (3-4 cm above carina)
- intubate less than 30 sec, if not, re-oxygenate
7) Post intubation management
Aspiration of as little as ____ mL of gastric content may result in significant injury to the patient
20
Prevention of Endotracheal Tube complications:
-tube obstruction
- bite block
- humidify
- replace old ETT’s
Prevention of Endotracheal Tube complications
-Tube displacement
- secure tube
- restraints
- sedate
Prevention of Endotracheal Tube complications
- Sinusitis and nasal injury
- Avoid nasal intubations
- antibiotics
Artificial Airway Cuffs-
-purpose
- small balloon inflated to prevent leakage of inhaled air past the tube into the upper airway
- CLOSED SYSTEM
Artificial Airway Cuffs-
-Minimal Leak technique
-place stethescope over larynx and inject 0.5 ml of air into the cuff at a time until small inspiratory leak is auscultated
Artificial Airway Cuffs-
-Minimal Occluding Pressure
inflate then decrease by 0.2 ml. when you hear an air leak increase to the point air leaks and trachea is sealed
“darth vadar “ noise
how to suction a patient?
- give 3 100% breaths
- do not suction for more than 10-15 seconds
What to do if ET tube pulled out?
- page doctor
- listen to lungs sounds
- call RT
what is mechanical ventilation
any means in which physical devices or machines are used to either assist or replace spontaneous respirations
Indications for mechanical ventilation
- relieve upper airway obstruction
- Acute lung failure
- PaO2
What must you give the patient when on Mechanical Ventilation
- sedation
- neuromusclular blockade
Mechanical Ventilation:
-Negative-Pressure ventilators
- “iron lung”
- applied externally to patient
- ** decreases atmospheric pressure surrounding the thorax to initiate inspiration
Mechanical Ventilation:
-Positive Pressure Ventilators: (PPV)
-forces gas into the lungs to expand them
Mechanical Ventilation:
-Positive Pressure Ventilators: (PPV) 2 types
1) Volume cycled
2) Pressure cycled
Positive pressure ventilators:
1) VOLUME CYCLED
- gas flows into lungs until a preset VOLUME of gas has been delivered
- constant tidal volume regardless of compliance and airway resistance
Positive pressure Ventilators:
2) PRESSURE CYCLED
- gas flows into the lungs until a preset PRESSURE is reached
- delivery of desired tidal volume is NOT guarenteed
Mechanical Vent. Settings
-Trigger
-what causes the vent to deliver breath (pressure or flow)
Mechanical Vent. Settings
-Sensitivity
determines the amount of effort patient must generate before the ventilator will deliver a breath
Mechanical Vent. Settings
- Sensitivity:
- if setting TOO LOW
- if setting TOO HIGH
- pt works harder to breath
- asynchronus breathing
Mechanical Vent. Settings
-Respiratory rate
-6-20
* key way to control CO2
adjust according to PaCO2
Mechanical Vent. Settings
-Tidal volume
-volume delivered per ventilator breath
-500-800 mL
N (6-10 ml/kg/IDB)
ARDS (4-8)
Mechanical Vent. Settings
-fraction of inspired O2 (FiO2)
% of air that is being delivered by ventilator each breath
21-100%
*must maintain PaO2 80-100 and SaO2 >90
Mechanical Vent. Settings
-Positive end expiratory pressure (PEEP)
- prevents shunt
- keeps alveoli open to promote gas exchange
- AFTER EXPIRATION
PEEP normal value
3-5
ARDS: 5-20
Mechanical Vent. Settings
-Flow rate
determines how fast tidal volume will be delivered
Flow rate:
- LOW
- HIGH
- allows long inspiration
- allows fast inhalation for longer exhalation
What type of flow rate does COPD want?
HIGH FLOW RATE
Mechanical Vent. Settings
-I:E ratio
duration of inspiration to expiration
1:2
Mechanical Vent. Settings
-Pressure Limits
-regulate maximum amount of pressure the ventilator will generate to deliver preset tidal volume
Positive End Expiratory Pressure
-functions
- Maintain airway pressure
- Increases FRC
- improves oxygenation by opening collapsed alveoli at end of expiration
- decreases FiO2 to less toxic
minute volume (MV)
total volume of gas inhaled or exhaled over 1 minure
Peak Inspiratory Pressure PIP
airway pressure at maximum inspiration
-AIRWAY PROBLEM : mucus plug
Plateau pressure
Pressure applied to small airways and alveoli during PPV
- Measured during an inspiration pause on the mechanical ventilator
- LUNG COMPLIANCE
Modes of Ventilation:
-continuous mandatory volume (CMV) aka Assist control (AC)
-delivers gas at a preset volume or pressure
-patient CAN either trigger the ventilator or machine will give a breath on its own
-
CMV/AC
- advantages
- disadvantages
- indications
- guarentees a minimum minute ventilation
- can lead to RESP ALKALOSIS and Hypotension
- pts who need full ventilator support and need a steady vt
Example of a Ventilator Mode:
-AC 16 (BUR)
Back Up Rate
-if patient unable to trigger breathing
Modes of Ventilation:
- Synchronized Intermittent Mandatory Ventilation (SIMV)
- a mix of MANDATORY breaths and ASSISTED breaths
- delivers preset volume or pressure while allowing pt to breath spontaneously
- “works out lungs”
Difference between SIMV and AC
-SIMV allows patient to breath without any support when they want to, AC allows support by ventilator
SIMV
- advantages
- disadvantages
- Indications
- guarentees minimun minute ventilation. Lower pressure than AC
- Increased WOB for patient-fatigue
- needed for patients who are hyperventilating or have high airway resistance
REVIEW AC and SIMV
AC- receive full support
SIMV- receive partial support
Modes of ventilation:
Pressure control ventilation (PCV)
- MANDATORY breaths only
- patient CANT trigger ventilator
Pressure Control Ventilation (PCV)
- advantages
- Disadvantages
- Indications
- prevents excess airway pressure, avoids alveolar over-distention, leads to earlier weaning
- uncomfortable, requires DEEP SEDATION
- Pts with high risk barotrauma
Modes of Ventilation:
- Pressure support ventilation (PSV)
- No mandatory breaths
- preset positive pressure on patients inspiratory efforts
- patient controls rate, flow, and vt
- Pt has control of breaths!
Pressure support ventilation (PSV)
- adavantages
- disadvantages
- indications
- supports breathing and helps patients with a stable respiratory drive to overcome increased airway resistance, reduces their work of breathing
- apnea alarm is only back up
- assist spontaneous breaths in SIMV or helps weaning
neuromuscular blockade
paralysis of a patient using drugs that paralyze skeletal muscle but don’t affect cardiac or smooth muscle
Uses of neuromuscular blockades
- aids in intubation
- acts by competing with ACh
- stops muscles from depolarizing
what must you give when you give a neuromuscular blockade?
- pt is paralyzed but fully CONSCIOUS
- GIVE SEDATIVE and PAIN control
- versed as an IV drip
Neuromuscular Blockade Nursing considerations
- patent airway
-ambu bag
ABGs
-position change and passive ROM
-Protect eyes with lubricant and eye-pads
Train of 4: 4/4 3/4 2/4 1/4 0/4
- less than 75%
-75%
-80% DESIRED
-90%
100%
Troubleshooting alarms
DOPE
D- disconnections
O- obstructions
P-pressure/pneumothorax (check lung sounds and chest Xray)
E- equipment
why would an alarm say low pressure?
- patient disconnection
- tubing disconnection
- cuff leak
why would an alarm say high pressure?
- patient coughing
- secretions or mucus in airway
- patient fighting the ventilator
- increased airway resistance
- reduced lung compliance
- water in circuit
- kinking in the circuit
- problems with I/E valves
why would patient be agitated or in dis-synchrony on the ventilator ?
- secondary to overall discomfort–>increase their sedation
- ## secondary to air hunger–>adjust respiratory settings (vt, flow rate, ect)
complications of mechanical ventilators
- oral and dental damage
- nasal damage
- decrease in C.O
- barotrauma/voltrauma
- emphysema
- infection
- increase WOB
Barotrauma/Volutrauma
- alveolar overdistention with resiliant alveolar rupture and air leak
effect of mechanical ventilation on renal system
decreased urinary output d/t low perfusion to kidneys
* tell Dr if
Effect of mechanical ventilation on GI?
- stress ulcers
- give pepcid
When to draw ABGs when on a mechanical ventilator
- 30-60 min after ventilations begin
* DO NOT SUCTION for 15 min before drawing ABGs. alters O2 values
what else should be checked besides ABG’s
- Hgb
* ensure the absence of anemia and adequate perfusion
*** what to do if:
INCREASED PaCO2
INCREASE rate or tidal volume
*** what to do if:
DECREASED PaCO2
DECREASE rate or tidal volume
*** what to do if:
INCREASED PaO2
DECREASE FiO2 or PEEP
*** what to do if:
DECREASED PaO2
INCREASE FiO2
Process of Weaning:
WEANING
W-WOB E- electrolytes A- attitude N-nutrition I-infection N-nonspecifc G-gases
- make sure to educate the patient
- only do spont. breathing trial for 30-120 min
weaning methods
1) SIMV weaning
- gradual transition from vent to spontaneous breathing
weaning methods:
2) PSV weaning
PS mode at a level that achieves spontaneous vt
-augments pt breathing with a + pressure boost during inspiration
ACUTE LUNG FAILURE
inability of lungs to maintain adequate oxygenation of the blood with or without impairment or CO2 elimination
Acute Lung Failure:
Type 1
low PaO2 (
Acute Lung Failure:
type 2
low PaO2 (45)
Acute Lung Failure management
- O2 >90%
- PaO2 45??
- ventilation: pH
Acute Respiratory Distress Syndrome (ARDS)
non-cardiogenic pulmonary edema
-alteration of the alveolar capillary membrane
ARDS causes:
DIRECT
- aspirate gastric content
- pneumonia
- near drowning
ARDS causes:
INDIRECT
- sepsis
- trauma
- pancreatitis
- blood transfusions
- DIC
ARDS pathophysiology:
injury occurs–> inflammatory response–> immune system releases protein mediators–> this increase the permeability of alveolocapillary membrane–> allows large molecules to enter–> collapse of the alveoli and makes lungs less compliant (stiff)
ARDS progression:
1) Exudative phase
- release of INFLAMMATORY MEDIATORS
- within 72 hrs of injury
- alveolar edema and Type 1 epithelial cells (flooding)
- Xray changes in 24 hrs
- mediators cause damage to alveolar hypoventilation, V/Q prob, intrapulmonary shunting, hypoxemia
ARDS progression:
2) Fibropolierative phase
- HEALING begins
- granulation and collagen deposits
- fibrotic alveoli
- scarred pulmonary capillaries
ARDS progression:
3) Resolution phase
- REMODELING
- alveolar fluid goes to interstitium
- Type 2 epithelial cells multiply
ARDS S/S
- within 48 hrs
- restlessness
- HTN
- tachycardia
- SOB
- accessory muscle use
- lung sounds: clear, crackles, or rales
ARDS diagnostic findings
-ABGs
- low PaO2
hypoxemia: PaO2/FiO2 less than 200
ARDS diagnostic findings:
-CXR
“white out”
ARDS diagnostic findings:
-PA cathater
PAOP
ARDS Treatment:
-establish airway
-HIGH PEEP!! keep alveolar open
-sedate
-A-line to maintain BP
corticosteroids to help with membrane permeability
-nutrition: TPN
PRON POSITION
symptoms of respiratory distress associated with ARDS begin within __ hours of insults to lungs
24-48 hrs
what is happening at the cellular level to cause hypoxia in ARDS
leaking of alveolocapillary membranes
high levels of PEEP can cause what ?
Decreased C.O because high intrathoracic pressure
ARDS POSITIONING txt
- preferential blood flow occurs to the gravity-dependent areas of the lungs
- positioning is used to place the least damaged portion of the lungs into a dependent position
- prone
- rotation
ARDS positioning:
1) Prone
-improves oxygenation
ARDS positioning:
2) Rotation
-keep them on special beds 24-48 hrs
What would you do first to increase oxygenation in an attempt to decrease FiO2 when in oxygen toxicity?
Increase PEEP
Inadequate PEEP can increase the risk of:
Atelectrauma: open/close can cause alveolar damage.
