Lung Function Under Mechanical Ventilation
When using IPPV (Intermittent Positive Pressure) these are 2 adverse factors that happen to the body.
What is increased intrathoracic pressure (inspiration) resulting in decreased blood return to the heart
These are 4/7 common errors in anesthesia techniques that can result in anesthesia gas contamination in the operating room
What are
Vaporizer/N2O without a patient connected to circuit
Poorly fitted mask, LMA or other airway device
Uncuffed ETT too small for orifice or poorly seated cuffed ETT
Spillage
Emission of gas from deeply anesthetized patient
Emptying breathing circuit of anesthesia gases while circuit is disconnected from the patient
The ascending ventilator bellows is a safer choice because it based upon this movement
What is exhalation?
It is easier to see a leak or disconnect because it will not rise during exhalation.
However a descending bellows will fall whether or not there is a leak or disconnect due to the weight.
Because this device reduces evaporation from the airway and keeps the mucous membranes moist and from from debris its nick name is
What is artificial nose?
This is the best way to secure medical gas cylinders
What is in the upright position either changed to a wall or confined in a rack with the cap on to protect the stem
If the tank cannot be secured standing, then it must lie on the ground
When using IPPV (Intermittent Positive Pressure Ventilation) these are four ever present risks of traumatic lung injury
What is
Barotrauma (pressure)
Volutrauma (volume)
Atelectrauma AKA Shear trauma (pressure + volume)
Airway irritation (coughing, bucking, straining)
Can use PEEP to lessen injury, but increases physiologic dead space and reduces cardiac output
This is the most common operating room ventilation system
What is non-recirculating which pumps gas from the outside, removes stale air and has 15 or more air exchanges per hour
Volume controlled mechanical ventilation puts the patient at risk for these 2 issues
What is
Barotrauma and Worsen airway resistance
This is because the TV, rate and I:E ratio are set
A passive HME takes this many minutes to maximum efficiency
What is 20 minutes
The fail-safe valve & alarm system on the anesthesia machine performs these 2 actions when the PSIG of oxygen falls at or below 30
What is
Stops/reduces flow of secondary gas
Sounds an audio/visual alarm until pressure returns and cannot be paused for >120
Does not ensure safe O2 ratio, adequate flow or recognize gas type
These are 4 out of 7 adverse factors that occur to the lungs when an ETT is used.
What is
Retention of secretions r/t cough suppression
Damage to mucocilliary layer
Water loss r/t decreased humidification
Increase secretion viscosity r/t dry gases
Heat loss
V/Q mismatch (dead space)
WOB increases
During spontaneous or manually assisted ventilation with a circle system, the WAG leave the circuit via this valve
What is the APL or "pop-off" valve
Pressure controlled mechanical ventilation is based upon these two factors
What is peak airway pressure and lung compliance.
Patient at risk for hypoventilation and poor oxygenation
These are the 3 disadvantages of an HME
What is
Increased dead space
Increased resistance
Becoming obstructed
This mechanism will automatically turn down the flow of N2O when the O2 flow is decreased
What is the oxygen ratio proportioning system
PEEP (Positive End Expiratory Pressure) causes this adverse physiological to the lungs
What is decreased venous return due to increased intrathoracic pressure (exhalation)
Barotrauma is a hazard of scavenging system for these 2 possibilities
What is negative pressure from the vacuum and positive pressure line occlusion
Pressure controlled guarantee ventilator mode has this advantage
What is changes pressure based on compliance.
Good for laparoscopic procedures
Low humidity in the airway can cause these physiological issues (name 2/4)
What is
Viscous mucous causing obstruction
Increased airway resistance (atelectasis-infection; decreased FRC, >V/Q mismatch
Loss of cilia function (normal is 1000 beats/min)
Damage (ulceration/necrosis to trachea with 1 hour of dry gassing)
Vaporizers should be taken out of service if any of these 3 actions should occur
What is
Overfilling
Tipping/tilting vaporizer >180 degrees
Filling with the wrong agent
These are 3 positives events that may occur to lung function during mechanical ventilation
What is
Decreased WOB
Improved function of abnormal lung dynamics
Delivery of medication: Volatile agents, bronchodilators
These three activities can help prevent WAG exposure
What is
Leak testing the system (low pressure test)
Turn off gas when not in use
Fill vaporizers when OR is not in use
This mode of ventilation supports breathing efforts of patient
What is pressure support?
Good for cases where NMB is not needed and helps the provider see recovery from NMB
These are 3 out of 5 factors that make an ideal HME
What is
warming and humidifying gases to physiological temperatures
No resistance to gas flow
No dead space
No risk of infection
Easy and safe to use
The following items are testable on next week's exam
What is everything in modules 1, 2 and 3 to include anything on the care plan to include calculations