The flashcards below were created by user
Martia
on FreezingBlue Flashcards.
-
Ventilation
the ability to move air in an out of the lungs
-
Respiration
- gas exchange at the cellular level
- O2 in and CO2 out
-
Reasons for Ventilatory Support
- Acute ventilator failure
- Acute respiratory failure (hypoxemia)
- Pulmonary mechanics - obstruction, low compliance
-
Acute Ventilatory Failure
- most common need for ventilation
- lungs inability to maintain adequate alveolar ventilation
- causes acute respiratory acidosis
- high CO2 (>50mmHg)
- low pH (<7.3)
-
acute respiratory failure (hypoxemia)
- pO2<60mmHg
- O2 sat <88%
- shunting occurs - pulmonary capillary perfusion is normal but alveolar ventilation is lacking
-
pre-intubation
- call anesthesia and respiratory
- make sure patient is a full code
- set up suction
-
Post-intubation
- secure ET tube
- document placement (at lip)
- auscultate bilaterally
- end tidal CO2 - measures CO2 in the exhaled breath to ensure that tube is in trachea and not esophagus
- CXR to confirm placement
-
tracheostomy
- surgically created
- used for a prolonged need of an artificial airway
- can improve weaning
- improves patient discomfort and prevents skin breakdown that can occur from ET tube in mouth
-
Negative pressure ventilator
- iron lungs
- we naturally breath based on negative pressure - lungs expand causing negative pressure causing air to be pulled into the lungs
-
Positive pressure ventilation
- pushes air into lungs
- volume cycled
- pressure cycled
- time cycled
- flow cycled
-
volume cycled positive pressure ventilator
- delivers a preset volume of air to lungs
- most common mode
- pressure in the lungs vary
- increased risk of barotrauma
-
pressure cycled positive pressure ventilation
- delivers a preset gas pressure to lungs
- vent pushes air until there is a certain pressure in the lungs
- amount of air varies
-
time cycled positive pressure ventilation
- preset inspiration time
- volume and pressure may vary
-
flow cycled positive pressure ventilation
- pressure augmentation during inspiration
- decreases work of breathing
-
Tidal Volume
- amount of air delivered to the lungs in one breath
- normal TV =5-12mL/kg (500-800mL)
- complications of high TV - barotrauma (creates high pressure and can rupture alveoli)
- complications of low TV - hypoventilation (lead to hypercapnia)
- consider lung compliance - lungs may be too stiff and O2 can't be pushed in...so avoid high volumes in these cases
-
Fraction of inspired oxygen (FiO2)
- percentage of oxygen of inspired gas
- ranges from 0.21-1.0 (21%-100%)
- usually start with the lowest amount as possible
- complication: oxygen toxicity - damages endothelia lining and decreases mucous and surfactant protection - common with COPD patients
-
Rate
- # of breaths per minute delivered to patient
- normal: 6-20
- in some ventilator modes the rate can be controlled by the patient or the vent
-
positive end expiratory pressure (PEEP)
- extra pressure at expiration that maintains pressure in the alveoli to keep them open a little
- it increases the amount of O2 that the capillaries are able to extract from the alveoli - leads to increased O2 in the blood
- primarily used for refractory hypoxemia to prevent atelectasis
- up to 30cmH2O
- complications - barotrauma and decreased CO
- Auto PEEP - build up of pressure leading to air trapping
-
peak airway pressure (peak inspiratory pressure)
- pressure required to deliver volume of air
- healthy lungs need 20cmH2O
- goal: <40cmH2O
- value will be increased with decreased lung compliance, worsening pulmonary status, coughing, need for suctioning
- value will be decreased with improving status
-
Assist Control ventilator (continuous mandatory ventilation)
- pt. gets set # of breaths per minute at a set TV
- additional inspiratory breaths are assisted at set TV
- advantage: allows resp muscles to rest
- disadvantages: high resp rate will cause hyperventilation (resp alkalosis)
-
Synchronous intermittent mandatory ventilation (SIMV)
- pt. gets set # of breaths per minute at set TV
- pt. has to bring in their own TV for any additional breaths that are attempted
advantages: decreased risk of hyperventilation, forces exercise of resp muscles, used for weaning - disadvantages: potential for fatigue d/t inadequate rest periods
-
Continuous positive airway pressure (CPAP)
- no preset resp rate or TV
- pt. generates their own resp rate and TV
- used for weaning
- only provides a source of positive pressure O2
- often used with pressure support ventilation (PSV)
-
pressure support ventilation (PSV)
- adjunct to weaning mode
- helps to overcome increased airway resistance by applying positive pressure
- decreases work of breathing
- triggered by spontaneous breath (pt. own attempt at breathing)
- 5-15cmH2O
-
high pressure alarm for vents
- indicates resistance in the circuit (vent has trouble pushing TV into the lungs)
- secretions
- coughing
- tube kinked or pt biting tube
- high lung compliance
- poor synchronization
-
low pressure alarm on vents
- indicates a disconnection or leak in the system
- air is being pushed in but it isn't meeting any resistance
- check tubing and connections
-
complications of mechanical vents
CV - decreased CO (esp if TV is too high b/c too much air in chest cavity leaves little room for the heart to expand), preload and SV
pulmonary - changes flow of gas, O2 toxicity, risk of VAP, barotrauma
renal - decreased perfusion
GI - stress ulcer (very common)
neurovascular - decreased flow to head, decreased venous return from head (increased ICP)
-
O2 toxicity
- >80% FiO2 for >48 hours
- damages endothelium lining of alveoli, decreases mucous and surfactant production
- symptoms (nonspecific)- malaise, fatigue, substernal discomfort
- add PEEP and reduce the FiO2 to decrease risk of O2 toxicity
-
Ventilator Bundle
- HOB>30 degrees
- prevent stress ulcers (H2 blockers/ PPI)
- DVT prophylaxis
- sedation vacation - wake up Q24H to assess neuro status
- oral care Q4H
- consider weaning trial - assess daily
-
Artificial airway complications
insertion trauma - bleeding; damage to mucous membranes
cuff trauma - compromise arterial capillary blood flow; monitor cuff pressure Qshift (20-25mmHg)
vocal cord paralysis or damage - hoarseness may be temporary or permanent
swallowing dysfunction- can cause chronic aspiration
tracheoesophageal fistula (rare) - can cause gastric secretions to be aspirated into the lungs
-
ineffective airway clearance
- suction only when needed
- hyperoxygenate and hyperventilate
- suction for 5-10 sec maximum
- reassess
- return pt to vent
- document secretion amount and characteristics
-
impaired gas exchange
- alveolar hyperventilation - can be caused by anxiety and pain
- alveolar hypoventilation - can be caused by decreased level of consciousness
-
ineffective breathing patterns
- tachypnea - alteration in acid/base balance
- bradypnea- hypooxygenation
- patient ventilator dysynchrony - pt expiration while vent is on inspire
resp distress - manually bag pt at 100% FiO2 first and then call for help
-
alteration in cardiac output
- common in high PEEP patients
- increased intrathoracic pressure over distends the lungs and prevents cardiac filling
- CO is usually decreased and hypotension may occur
-
Weaning
- assess readiness to wean (RTW)
- FiO2<50%
- PEEP<5cmH2O
- nutrition optimized
- afebrile
- no GI bleed; stable Hgb
- stable hemodynamics
- mental status
-
weaning modes
manual weaning - remove pt from vent and place on t piece. serially increase time of the vent
ventilator weaning - more common
-
CPAP weaning
- pt remains attached to ventilator
- vent provides O2 air
- pt does all the work of breathing
- may have PSV added
-
Intermittent mechanical vent weaning
- pt starts off with high # of preset breaths
- overtime the preset breaths are reduced which forces pt to do more work of breathing
- builds endurance of resp muscles
- often used with difficult wean patients
-
assessing a weaning trial
- tidal volume - increased
- resp rate - decreased
- vital signs w/in normal ranges
- cardiac rhythm
- ABGs
- general appearance
- rapid shallow breathing index (RSBI) - RR/TV - target score is <100
-
postextubation care
- stridor/laryngospasm is #1 immediate complication
- humidified air with face mask
- chest PT
- cough and deep breathing
- swallowing evaluation
-
Noninvasive intermittent positive pressure vent (NIPPV)
- mask covers nose or mouth and nose
- less risk of infection
- complicationsgastric distention - air goes into abd
- aspiration - keep NPO
- hypoventilation
- skin irritation
- nasal problems
- conjunctivitis
- removal/noncompliance
|
|