mechanical ventilation Flashcards
goal with mechanical ventilation
-supportive respiratory therapy that is used to support and improve ventilation and perfusion
what does mechanical ventilation maintain
- alveolar ventilation appropriate for the patient’s metabolic needs
- correct hypoxemia
- 02 transport
- Bridge to recovery or until decision for EOL
- Non Curative
definition of mechanical ventilation
- Oxygen moved in and out of lungs by mechanical means
- Required Endotracheal tube (ETT) or tracheostomy (Trach)
types of mechanical ventilation
- Negative Pressure Ventilation
- Positive Pressure Ventilation
1. Volume Ventilation or Pressure ventilation
2. Other: PEEP and CPAP (NIVVP)
indications for mechanical ventilation
- Apnea
- Unprotected airway
- Acute Respiratory Failure
- Acute Respiratory Distress Syndrome (ARDS) - Severe Hypoxemia
- Severe Respiratory Muscle fatigue/impairment
data r/t indications
- Failure to ventilate
- PCO2 > 50 mmHg , pH 7.3 or less
- PaO2 < 50 mm Hg
- Respiratory rate: Increased ineffective > 40
- Low RR/ Breathing Ineffective: RR <8* , apnea (apneic periods), diminished or absent lung sounds, shallow expansion, Acute Resp Failure, ARDS , respiratory muscle fatigue
ventilator modes
-methods by which the inspirations/expirations are provided or set
mode selections
- Based on individual patient status
- ABG, LOC, Respiratory drive or therapeutic needs
- Provider ordered
- RT and RN : recommends and monitors
- Mode Setting placed into Ventilator control panels
how to decide ventilator settings
- individualized
- Pt weight (ideal weight)
- LOC
- Pt Response
ventilator settings
- Fraction of Inspired Air: FiO2
- Rate
- Tidal volume
- Positive End-Expiratory Pressure
- Sensitivity
- High Pressure limits
WHAT IS THE TIDAL VOLUME
-amount of gas delivered each breath
what is the RR
-number of breaths delivered each minute
Fi02
-fraction of inspired oxygen
pressure limits
-if the pressure goes too high (past this) excess will be released
negative pressure ventilation
- Device Chamber surrounds chest with negative pressure.
- Result: Chest is pulled “outward” and Air enters lungs
- Expiration is positive
- Examples: iron lung, cuirass
advantage to negative pressure ventilation
-no artificial airway required and home use is possible
disadvantage to negative. pressure ventilation
- volume per breath (unsure how much getting), uncontrolled therapy, skin irritation/damage
when is negative pressure ventilation usually used
- used in pts . With neuromuscular disorders such as MS or MD
- Not used in critical care for acute impairment
positive pressure ventilation
- Positive Pressure applied to airways at inspiration
- Expiration: Passive
- Intrathoracic pressure increases with inspiration as the ventilator send measured tidal volume or breath in – this stays positive until the breath ends
modes on positive pressure ventilation
- Volume modes: used in past
- Assist Control (AC)
- Synchronized Intermittent Mandatory Ventilation (SIMV) - Pressure modes: more commonly used, safe, effective
- Pressure Support Ventilation
- PEEP
- CPAP
ventilator mode: volume type- assist control
- Tidal Volume (Vt) are set
- Number of Breaths are set
- The patient Can initiate own breaths
- Each breath still provided at SET Tidal Volume (Vt)
-rate set plus whatever breaths they take on own
advantages to assist control
- Allows decrease WOB
- Allow some independence by patient
disadvantages to assist control
- Hypoventilation if settings are too low
- Hyperventilation if patient is breathing too fast
if patient initiates a breath on assist control what will the end tidal volume be if was set to 550
550
On AC mode: if patient initiates a breath How does that effect the Rate?
The patient rate will be 12 PLUS whatever breaths taken on own; so the RR is now 13
PPV modes- SIMV (Synchronized intermittent mandatory ventilation)
-A set number of breaths with set volume
-Patient can initiate own breath at own volume
I.e.: SIMC 10, Vt 650 FiO2 40%
-Each of the set 10 breaths are delivered at Vt of 650
-Pts. Own breath could be at any vT the patient is able to pull
-The “synchronized” breath is delivered at the end of expiration so patient is comfortable
SIMV advantages
- Decrease in positive pressure breath
- Improving C. O. since allowing to take breaths on own
SIMV disadvantages
- Hypoventilation is rate is set too low & pt not taking own breath
- Close monitoring
- If rate is set too low: pt may become fatigued or acidotic
SIMV use in the past and now
- In the past SIMV was used for weaning
- Improved synchrony between pt and ventilator
- More comfort for pt.
- Used in combo with pressure support for wean
-With newer Ventilators this Mode not used very often , might find SIMV used in rehab units
Pressure control ventilation (PCV)
- Provides set rate
- Amount of pressure needed to provide Rate is Controlled
- No Tidal volumes set:
Airway pressure release ventilation (APRV)
- Allows for release of pressure at any time
- Pt can take a breath and the ventilator allows
- Less PPV
- Used for patients who need high pressures to open up and recruit alveoli
- Reduces need for deep sedation
Pressure Control Inverse Ration (PC-IRV)
- Combines pressure controlled ventilation with inverse ratio of Inspiration and Expiration.
- Normal RR ratio is 1:2 or 1:3
- This IRV is 1:1
- Used in ARDS,
- Not everyone responds
Mechanical Ventilation: other settings: Adjunctive Ventilator /Respiratory support Settings
- Positive End Expiratory Pressure (PEEP)
- Continuous Positive Airway Pressure (CPAP)
- This can be Set on Ventilators
- and we also use it in accessory devices - Pressure Support (PS)
PEEP
- Prevents alveolar collapse
- aeration of alveoli
- provides counter pressure to fluid extravasation
PEEP indication
- pt. cannot maintain a pO2 greater than 60 mm Hg on less than 50% FiO2
- PEEP is commonly used in patients who are suspected of having a pathology that predisposes their alveoli to collapse, this is generally due to a large amount of fluid in the lungs
mechanics of PEEp
- Normally, the pressure in alveoli is zero with exhalation.
- By adding pressure to the alveoli at the end of expiration, lung volume during expiration and between breaths increases, FRC increases, alveoli remain open longer or open if closed
major purpose of PEEP
- maintain or improve oxygenation while limited risk of O2 toxicity
- Allows for lower levels of FiO2
uses PEEP cautiously in
Increased ICP, Low Cardiac output, hypovolemia
DISADVANTAGES TO peep
- Decrease in C. O.
- Hemodynamic instability: Hypotension and Tachycardia as a result of Decreased C.O.
- Barotrauma
pressure support
- Preset Pressure with each spontaneous breath
- Applied throughout the entire inspiratory phase
- Decreases WOB by overcoming increased airway resistance from artificial airway and ventilator circuitry = Reducing O2 demand, allows muscle recovery
- Used in Weaning Process
- Can be applied to other modes
Other Vent Settings: Continuous Positive Airway Pressure (CPAP)
- Pt self initiates own respiration
- With own tidal volume and rate
two main care issues when patient is on a ventilator
- Artificial Airway
2. Mechanical Ventilator
Nursing and Interprofessional Management: Artificial Airway
- Maintaining correct tube placement,
- Maintaining proper cuff inflation,
- Monitoring oxygenation and ventilation
- Maintaining tube patency
- Assessing for complications
- Providing oral care and maintaining skin integrity
- Foster comfort and communication.
two major complications with artificial airways
-unplanned extubation and aspiration.
care of the patient on the ventilator: preparing the family
- Explain purpose, rationale. procedures, alarms, safety needs etc.
- Explain associated medications, lines,
- Allow for visitation
Care of the patient on the ventilator: respiratory assessment
- every 1-2 hours
- Observe , Auscultate, Assess Breath Sounds, Chest expansion Monitor Changes
- Airway security, Ensure proper tube placement
- Monitor ABGs, CXR, SpO2, EtCO2,
- Assess S/S of any changes positive or negative (Respiratory distress, increase restlessness, secretions, Change in VS, diaphoresis, chg in skin color , s/s hypoxia, hypercapnia)
-Document in EMR
Monitor volumes, ventilator status
Assess devices, tubes,
Care of the patient on the ventilator: Maintain airway patency and effective airway clearance
-Manage secretions: Suction prn; in-line suctioning
-Promote alveolar recruitment (Chest PT,
Reposition: Turn pt. as condition allows. Min Q 2hrs,
Monitor I & O)
-Prone positioning, lateral rotation bed used to promote otherwise unused alveoli in dependent position.
-Bronchodilators as ordered
Care of the patient on the ventilator: mobility
- EARLY MOBIITY
- Improved outcomes, Less complications, less death,
- less complications ,
- Turn, turn, turn,
- Prone
- Get pt up and moving
Care of the patient on the ventilator: maintaining nutrition
- Increased calories need due to hypermetabolic state.
- Enteral Feeds: “tube feeds” preferred
- Consult dietary for Specialized formulas and goals
- Parenteral IV TPN can be used
- If trach: eating with Aspiration precautions at each meal
Care of the patient on the ventilator: maintaining oral care and skin integrity
-Assess Skin : face, lips , tongue r/t airway and all over body for pressure areas – protect and treat as necessary
-Oral care every 2-4 hours
-Use toothpaste or gel
-Use 0.12% Chlorhexidine (CHG) every shift Q 12
-Rinse and store in dry place in between suctioning
-Change suction equipment every 24 hours
“SCRUB TO CLEAN… SWAB IN BETWEEN”
Care of the patient on the ventilator: saftey and accidental alarms
- Goal: warning, indicator of an events or important changes
- Check vent. settings frequently, check alarms frequently (once per shift and prn)
-Safety rule of ventilator alarms: If the cause of an alarm is not immediately found or corrected immediately, the patient should be removed from the vent and manually ventilated using a resuscitation (AMBU)bag until the problem is corrected.
Alarms- low exhaled TV
-d/t circuit leaks, airways leaks, pt disconnection
alarms: high pressure
- Related to anything that increased airway pressure in system
- Secretions built up, coughing, pt biting tube, kinks in tube
- Reduced compliance
- Water in circuit
Care of the patient on the ventilator: Securing ETT
- Unplanned extubation
- Stay with patient Call for HELP
- Keep BVM , suction equipment, oral airway, intubation tray with ETT at bedside
- Approx. 50% of patients who self or accidentally extubate get reintubated
- Make sure ETT is secure and exit mark documented
why is mobility an issue with ventilated pt?
- Mobility : restrained by mechanical ventilation
- Immobility r/t chemical paralytic (neuromuscular blocking agent, hemodynamic or Respiratory instability)
Care of the patient on the ventilator: pulmonary complications
- Volutrauma/Barotrauma secondary to high TV, PEEP, noncompliant lung
- Volutrauma/Barotrauma may result in pneumothorax
Ventilator associated pneumonia (VAP): Nosocomial lung infection
- Pneumonia-infection occurred after 48 hours or more after intubation.
- VAP is the leading cause of death among hospital-acquired infections
- exceeding the rate of death due to central line infections, severe sepsis and resp. tract infections in the non-intubated patients.
Ventilator associated pneumonia (VAP) STATS
- 9 – 27% of all intubated pt.
- Approx. 68% of ARDS pt develop VAP
- 50% develop VAP within 4 days of intubation
Hospital mortality
VAP is 46%,
32% without VAP.
VAP associated complications
-Increased ventilator time
-Increased length of stay in ICU
-increased length of stay
-Increased cost:
VAP adds $40,000.00 to a typical hospital stay.
causes of VAP
- Upper airway defenses bypassed (Microaspiration and aspirations of enteral feeding or other)
- Poor nutrition, Immobility
- Contaminated airway upon intubation
- Contaminated equipment
- Poor handwashing
- Decreased cough
- Poor monitoring of cuff pressure
VAP clinical manifestations
- Increased O2 requirement
- Purulent secretions Increased or change in secretions (amount, color, odor )
- Fever >38.0c (100.4)
- Change in breath sounds
VAP DX
- Increased WBC counts
- colonization sputum
- Chest x ray: infiltrates
ventilator bundle
- Ventilator patients are at high risk for several complications:
- VAP, venous thromboembolism (VTE), and stress-induced GI bleeding.
- “Ventilator Bundle”
- Elevation of HOB to between 30 and 45 degrees
- Daily “sedation interruption” and daily assessment of readiness to extubate.
- Peptic ulcer disease (PUD) prophylaxis
- Deep venous thrombosis (DVT) prophylaxis (unless contraindicated)
- Oral care with Chlorhexidine
VAP bundle outcomes
- VAP rates in those ICUs utilizing the Ventilator Bundle showed dramatic decrease in VAP (avg. 45% reduction in VAP rate); the decrease was in part related to working a collaborative team since only 3 of the 5 elements relate directly to VAP prevention.
- Teams that followed the bundle element in every patient every time have gone months without a single case of VAP.
Ventilator Bundle: VAP/aspiration precautions – Head of Bed
- HOB up may help decrease VAP by decreasing risk of aspiration of GI contents or oropharyngeal and nasopharyngeal secretions.
- Also helps to improve pt. ventilation
Ventilator Bundle: GI protection Peptic ulcer disease (PUD) prophylaxis
- Stress ulcers: most common cause of GI bleeding.
- -Bleeding from stress ulcers occurs in 30% of pt with ARDS on mech. ventilation
- Agents used to raise gastric pH may promote growth of bacteria in the stomach…with gastric reflux along the ETT endobronchial colonization may occur and precipitate pneumonia.
-Recommendation:
Administration H2 Blockers, cytoprotective , sucralfate or proton pump inhibitors.
Ventilator Bundle: Daily Sedation interruption “sedation vacation”
- Daily interruption in sedation
- Wake up and breath
- daily assessment of readiness to extubation has been shown to decrease time on the ventilator and thereby decreasing risk for VAP.
- Recommendation: Lighten or turn off sedation daily and assess for neurologic readiness to extubation.
-Pain meds are not withheld… only sedation
Ventilator Bundle: DVT prophylaxis
-There is a higher incidence of deep venous thrombosis in critical illness.
-Use anticoagulants as well as sequential compression devices
-Other interventions: not in Vent Bundle
sub glottic suction on ETT
changing of vent circuitry on prn basis.
Ventilator Wean – Spontaneous breathing trial (SBT)
- Trial Allows pt to breath on their own without removing ventilator
- Parameters for weaning (not a complete list):
- PaO2 > 60 mm Hg on FiO2 < 50%, PEEP < 8
- PaCO2 < 45 mm Hg
- RR < 30 bpm
- Spontaneous TV > 4 – 5 ml/kg
- Max inspiratory pressure (ability to cough) < - 20 cm H2O
- Pt. awake, alert, hemodynamically stable
Assess for patient:
Follows Command ?
Protect own airway ?
Wean from Ventilator
- Weaning is the process of reducing ventilator support and resuming spontaneous ventilation
- The weaning process individualized
-Methods of Ventilator modes to support Wean-Many! Some examples: PRVC CPAP via Ventilator T-Piece PSV SIMV
Ventilator Wean: Implications: Monitor pt. closely during the weaning process
- Weaning intolerance guidelines (not a complete list):
- Dysrhythmias
- Increase or decrease in pulse, BP
- Dyspnea, diaphoresis, restlessness
- Increase PaCO2, PaO2 < 60 mmHg
Ventilator Wean: Implications: Monitor and support newly extubated Pt.
supplemental O2 & humidification pulmonary hygiene: positioning, CDB suction, Yankauer for pt use nebulizer Swallow Eval
if pt not tolerating wean
100% FiO2 and re-intubate resume mechanical ventilation**
Ventilator Extubations
- Weaning: Nursing Implications
- Extubation typically done by RT and RN at bedside
- High Fowlers position
- Suction ETT, deflate cuff
- Remove securing device: tape, holders, ties
- Pt. breaths deeply, remove ETT
- Apply O2 -
- Obtain post extubation ABGs, pulse –ox
- Monitor for S/S of resp. distress
ABCDEF Bundle
-delirium bundle
-A Assess prevent manage Pain
B Both spontaneous awakening trials and spontaneous breathing trials
C Choice of analgesia and sedation
D Delirium Assess, prevent, and management
E Early mobility
F = Family engagement and empowerment
Other ARDS and ARF Treatment options
Adjunctive to mechanical ventilation High dose steroid therapy Prone positioning Surfactant therapy High frequency oscillator ventilation (HFOV) Extracorporeal membrane oxygenation ECMO/ECCO Nitric Oxide Neuromuscular blocking agents (NMBA)
What is the setting rate
-frequency of breaths per minute delivered
what is the tidal volulme setting normal
- 5 ml/kg
- 4.6-8 on mechanical ventilation
- 4.8 in ARDS
how to avoid barotrauma with tidal volume
- permissive hypercapnia (allows the Pco2 to rise in a controlled fashion in an effort to reduce lung injury and the burden of gas exchange)
- pco2 of 50-70 (normal is 35-45)
what is the positive end expiratory pressure
-applied at the end of the respiration cycle
sensitivity setting
-amount of effort from the patient required to initiate a breath
high pressure limit setting
- max pressure machine will generate to deliver each breath
- if pressure limit is met the ventilator will release excess pressure to avoid barotrauma (usually 10-20 cm above peak inspiratory pressure
- if the pressure gets too high excess will be released
When do you start to see adverse effects of PEEP
Greater than 12
What do to for low pressure alarms
Check connections
Check cuff lead in ETT (normal=20-25)
Benefits to CPAP
Gives continuous positive pressure during inspiration and expiration
Keeps alveoli open (prevent collapse during expiration)
What does immobility when on vent cause risk for
Dvt
Pressure ulcer
Contractures
Prolonged stay
Management for complications of immbility
Early mobilit Turn and reposition q 2 hours Rom Skin assessment Oral care
What to do for high pressure alarm
Suction Monitor for kinks Use bite blocks Reposition Bronchodilator Treat pain Confirm connections
Signs of barotrauma
Sudden agitation Cough High pressure alarm Hypotension Absent breath sounds
Management of barotrauma
Chest tube
How to prevent barotrauma
Decrease tv
Monitor peak airway pressure (highest pressure during reps. Cycle)
Optimal peep amount
5
When to start enteral nutrition
24-48 hours after intubation
