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