Ch. 19 Pilbeams Flashcards
Explain how negative pressure ventilators works?
intermittently by applying negative pressure to the entire body region below the neck or to the upper region of the chest. negative pressure is transmitted across the chest wall into the pleural space and into the alveolar space. The result is an increase in transpulmonary pressure which causes air to enter the lungs. Exhalation is passive and depends on the elastic recoil of the lungs and chest wall.
What is the primary goal of NIV in an acute care setting?
The avoidance of intubation and invasive ventilation in the acute care setting.
List 3 clinical benefits of NIV in the chronic care setting?
- Prolongs survival
- Improves functional capacity
- Improves duration and quality of sleep
Describe how the use of NIV in the acute care setting improves gas exchange?
NIV in ARF improves gas exchange by resting the respiratory muscles and increasing alveolar ventilation.
List 4 clinical disorders that manifest in chronic respiratory failure and require NIV supportive therapy?
- Chronic hypoventilation
- Nocturnal desaturation
- Respiratory muscle fatigue
- Poor sleep quality
List 5 symptoms of hypoventilation?
- Fatigue
- Morning headache
- Daytime hypersomnolence
- Cognitive dysfunction
- Dyspnea
What role does NIV play in “end of life” situations?
NIV may provide relief from severe dyspnea and preserve patient comfort. It may also reverse the acute process in disorders such as COPD or pulmonary edema and enable the patient to live longer.
What are the typical ranges for IPAP & EPAP settings on a BiPAP?
IPAP: 2-30 cmH2O
EPAP: 2-20 cmH2O
What clinical indicators demonstrate improvement of patient comfort?
• Dec. RR
• Dec. inspiratory muscle activity
• Synchronization with the vent
What Vt range should be used with NIV and how is it manipulated?
Vt = 5-7 or 6-8mL/kg
volume is manipulated by increasing the difference between the IPAP and EPAP. This is usually accomplished by increasing the IPAP.
Definition of NIV
The delivery of mechanical ventilation to the lungs using techniques that don’t require an endotracheal airway.
What are some risks that can result from IV?
• Inc. mortality rate
• Mortality & Morbidity
• Higher financial cost
What does NIV reduce the need for?
• Intubation
• Reduced mortality rate
• shortened hospital stay for patients requiring mechanical vent support
Types of NIV?
• Negative pressure ventilation
• positive pressure ventilation
• abdominal displacement ventilation
What is another name for negative pressure ventilators.
Body ventilators
What is the “iron lung?”
The first successful negative pressure ventilator
What is a chest cuirass (shell ventilator)?
A smaller portable negative pressure ventilator
What are 3 basic methods of NIV?
- Negative pressure ventilation
- Positive pressure ventilation
- Abdominal displacement ventilation
What are 2 types of negative pressure ventilation?
• Chest cuirass (shell ventilator)
• Iron lung
What are some disadvantages of NPV?
• Can’t access the patients body
• Not portable
What are the diff. types of PPV?
• Intermittent positive pressure ventilation (IPPV)
• Intermittent positive pressure breathing (IPPB)
• Noninvasive positive pressure ventilation (NIV)
What is the diff. bet IPPV & IPPB?
IPPB can have aerosolized medication
What is the diff. bet IPPV & NIV?
NIV - continuous; pt will get pressure for every breath
IPPV - pt will get pressure for some breaths
What are the clinical benefits of NIV?
What are the indications, symptoms, and selection criteria for NIV pts in acute respiratory failure in adults?
What is asthmaticus?
Pt does not respond well to asthma tx
What is hypoxemic respiratory failure?
Pt does not respond well to O2
What is one difference between NIV & IV?
Aspiration
What are the diff. types of ventilators?
• Pressure targeted ventilators (PTVs)
• Portable home care ventilators
• Adult acute care ventilators
What is pressure support?
The diff. bet IPAP & EPAP
What is the physiological goal of NIV?
To improve gas exchange, rest the respiratory muscles, and increase alveolar ventilation.
Why do we use PEEP with PSV?
To offset auto-PEEP and reduce the work required to initiate inspiration. Facilitates inspiration, thus increasing the Vt.
NIV provides a viable weaning alternative for patients who demonstrate ___________?
Respiratory muscle fatigue postextubation
It has been suggested that NIV________?
Reduces WOB & maintains adequate gas exchange.
In the acute care setting the assessment process may be viewed as a ________?
2 step process
What are the 2 steps for NIV in an acute care setting?
- Establishing the need for vent assistance according to the clinical and blood gas criteria.
- Exclude pts at inc. risk for failure and complications.
What are some symptoms of chronic hypoventilation (chronic care setting)?
• Excessive fatigue
• morning headache
• daytime hypersomnolence
• cognitive dysfunction
• dyspnea
What are some characteristics of PTVs?
Microprocessor controlled & electrically powered
PTVs are….?
• Pressure limited
• flow and time triggered
• flow and time cycled
PTVs devices are designed to inc _________?
Minute ventilation and improve gas exchange capabilities using the delivery of IPAP and EPAP.
What are the different modes that can be used with PTVs?
• CPAP
• PSV (IPAP/EPAP)
• Spontaneous/timed (S/T)
• average volume - assured pressure support (AVAPS)
What happens during the CPAP mode?
The patient breaths spontaneously at a set baseline pressure. The patient controls both the rate and depth of breathing.
AVAPS devices _______?
Automatically adapt pressure support to match a patient’s ventilatory needs by delivering an average Vt based on the patient’s condition.
What is the exclusion criteria for NIV?
How long does nocturnal use of NIV last?
4-6 hours
What are some indications, symptoms and selection criteria for NIV in chronic disorders?
When do we use the three types of ventilators?
For patients with hypoxemic respiratory failure & cardiogenic pulmonary edema
What is the Auto-Trak sensitivity system?
This option allows the clinician to further adjust thresholds that manage trigger and cycling and the level of auto-trak sensitivity.
What do most units have that improve synchronization between the pt and the vent?
An adjustable inspiratory and expiratory sensitivity controls.
What does the use of the rise time control do?
•Enhance pt comfort
•Reduce WOB
•Improve pt and vent synchrony
What are 2 other features of portable PTVs that can enhance pt comfort?
Ramp & delay time controls
Ramp allows ________ to _______ gradually over a set period over a set interval (delay time).
Positive pressure; increase
The ramp rate can be set in increments of?
1, 2, or 3 cmH2O
The delay time can be set in….?
5 min increments between 5 and 30 min.
The ramp and delay time controls are most likely used in?
Homecare or chronic care NIV
Portable PTVs have certain….?
Limitations that may restrict their use in ARF
When supplemental O2 is required it must be _____ into the system via the mask or into the circuit near the machine outlet.
Bled
What are the 4 factors that FiO2 is varied by?
- O2 flow rate
- Type of leak in port system
- Site where O2 is bled into circuit
- IPAP & EPAP
______of CO2 is a concern with any PTV that uses a single circuit gas delivery system because exhalation occurs through the intentional leak port and depends on the _____ flow of gas in the circuit.
Rebreathing; continuous
Key point 19.8
To prevent CO2 rebreathing EPAP levels should be set at 4 cmH2O or higher so adequate gas flows can flush CO2 from the breathing circuit.
What are the advantages of portable home care ventilators?
• compact size
• A/C current
• internal & external D/C battery
Portable home care vents are…
• Pt or time triggered
• pressure limited
• volume pressured or cycled
What are the diff. alarms you will see with portable home care vents?
•Low battery
•Power loss
•Low pressure
•High pressure
•Power switchover
•Apnea
What is this device?
The LTV 1200 ventilator
What do adult acute care vents offer?
• additional vent support options
• alarms
• precise FiO2
• more monitoring features
These extra features (for adult acute care vents) will benefit what pt’s?
ARF pt’s who require close monitoring and supervision during NIV
What is the most significant disadvantage of the adult acute care vent?
The inability of some machines to compensate for leaks.
In PSV mode air _____ cause gas flow to ________ during delivery of the breath, making the cycle threshold difficult to achieve.
Leaks ; increase
What is the leading cause of pt discomfort and noncompliance on CPAP and NIV?
• Excessive drying of nasal mucosa
• Nasal congestion
• Inc. nasal resistance
What will significantly reduce the drying of the nasal mucosa and lead to improve pt comfort and compliance?
Heated humidifier
Key point 19.9
Passover humidifiers should be used to treat or prevent nasal congestion and improve pt comfort. Bubble humidifiers and HMEs increase airway resistance and inspiratory WOB.
What are the different interfaces available?
• nasal masks
• oronasal masks
• total face masks
• helmets
• nasal pillows
• and mouthpieces with lips seals
What are the 2 most common disadvantages of the nasal masks?
- Leaks
- Skin irritation
What are the advantages and disadvantages of the various interfaces used in NIV?
What is this device?
Disposable nasal mask and head gear
What is this device?
Fitting gauge
What are these devices?
Gel-filled nasal masks
Using a sizing gauge for oronasal face masks, the clinician should choose the ______ size mask that comes closest to the following contact points
Smallest
What are the contact points (for sizing gauge)?
• the area just outside the sides of the mouth
• the area just below the lower lip
• the bridge of the nose
What is this device?
Nasal minimask and headgear
What is this device?
Nasal pillows and headgear
What is this device?
Full face mask OR oronasal face mask
What is this device?
Sizing gauge used to determine proper size of full face mask
What is this device?
Total face mask
What is this device?
NIV helmet
What is this device?
Mouthpiece and seal used to administer CPAP
What are the initial low pressure settings for IPAP & EPAP?
EPAP = 4-5 cmH2O
IPAP = 6-8 cmH2O
What are the steps for initiating NIV?
What are the predictors of success w/NIV?
What is the most significant indicator of success or failure?
Pt’s initial response to NIV
What are important factors for ensuring effectiveness of NIV and alleviating respiratory distress.
Pt tolerance and comfort
FiO2 is adjusted to maintain SpO2 at?
90-92%
The adequacy of vent support is determined by what?
ABG measurements
How long is the initiation of NIV?
1-2 hours
What is the criteria for terminating NIV and switching to invasive mechanical ventilation?
What are factors that affect aerosol delivery during NIV?
What can be administered in with NIV using a SVN, VMN, or pMDI w/spacer?
Medications (e.g. bronchodilators)
What is an example of an vibrating mesh nebulizer (VMN)?
Aerogen
What are some factors that affect efficiency of aerosol delivery?
• type of aerosol generators
• interface used during the tx
NIV depends on what?
How quickly the cause of respiratory failure can be reversed
Once the pt’s condition is stabilized, the mask may be removed for short periods according to what?
Patients tolerance
What are some complications associated with mask CPAP/NIV therapy?
_______ is administered as necessary during these times of the vent?
Supplemental O2
In the same manner as _______ , periods off the vent lengthen as the underlying condition improves and the pt shows acceptable vital signs, good gas exchange, and no respiratory distress.
SBT
What is the most important consideration for successful weaning?
The reversibility of the disease process that caused ARF.
The success of NIV depends on what?
Time and commitment from the members of the the patient care team
All members of the team must thoroughly understand the….
•Indications
•Benefits
•Complications of NIV
Studies have shown that ______ is required during the initial ______ to institute NIV than to establish conventional invasive ventilation.
More time ; 8-hour shift
What are some potential complications of NIV?
• aspiration pneumonia
• mucous plugging
• hypoxemia
• hypotension
• respiratory arrest
Know this picture
Portable home care ventilators are?
Electrically powered and microprocessor controlled
Characteristics of PCV?
- electrically powered
- pneumatically controlled
- external PEEP valve
What is one advantage of an HME?
Cheaper
What do you do if a pt is in distress?
Put them on a full face mask
If there is a leak in the mask what should you do?
Change size DO NOT TIGHTEN
a little leak is good
How do you know how much of a leak you have?
Machine will tell you
What is the range for leaks?
0-10
Definition of intact dentition?
Pt has teeth in their mouth
When should you get an ABG after initiation?
1-2hrs
What is aerophagia?
Swallowing of air
Auto pap does not have _____ bled in?
O2
Precise _____ is not available for PTVs?
FiO2
When should you set the FiO2 at 100% for NIV pts?
If there hypoxemic
T or F If the pt is not hypoxemic and you already know the FiO2 you don’t have to set it to 100%
True
What is the difference between alarms for NIV and ventilation?
Alarms for NIV have Ve and RR
Alarms for ventilation have RR only
