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72 Cards in this Set
- Front
- Back
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What's negative pressure?
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creates negative pressure outside of chest and pulls up chest
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Volume ventilation?
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other names are volume targeted, volume control or volume cycled. when patient is put on generally volume cycled
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Definition of volume ventilation?
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airflow is delivered by ventilation terminates inspiration phase of the respiratory cycle after preset volume is reached
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What are some major characteristics of volume ventilation?
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volume is set and remains the same whereas pressure varies based on lung status (compliance or/and RAW)
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What's the primary advantage of volume ventilation?
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constant Vt and/or minute volume delivered regardless of changes of compliance or RAW (constant C02)
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What are some disadvantages of volume ventilation?
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alveolar overdistention, may occur due to increase in PIP or plateau pressure. if lung condition gets worse. (increase in RAW or decrease in compliance)
(barotrauma, volutrauma) Need to monitor plateau pressure. |
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What needs to happen when PIP gets to 40-45?
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need to switch to pressure controlled ventilation
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What needs to change when it takes patient longer to exhale?
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need to change I:E ration to longer Te. (on patient with out obstructive disease)
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What are other names for pressure ventilation?
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pressure limited
pressure targeted pressure controlled |
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Definition of pressure limited time cycled?
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airflow delivered by the vent that terminates inspiratory phase.
Set pressure can't above set pressure |
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What are some major characteristics of pressure limited time cycled?
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pressure is set and remains constant whereas volume varies, depending on lung status
(can hyperventilate or hypoventilate in a matter of 1 minute) |
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What are primary advantages of pressure limited time cycled?
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constant pressure regardless of Vt delivered when control pressure limits pressure to decrease alveolar overinflation. If pressure is controlled, decreases overinflation
Has true decelerating flow. |
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What are some major disadvantages of pressure limited cycled?
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Vt and minute volume vary as lung conditions change. (RAW and compliance)
Minute volume will change, C02s will change, Vt will change will make ventilation change. |
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What's Full ventilation support?
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when vent does all work necessary to maintain ventilation
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What's the goal in full ventilation support?
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to achieve total control of patient's vent pattern. Patient does not breathe spontaneously or trigger vent
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What are some indications for full ventilatory support?
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initial acute respiratory failure
need for hyperventilation, generally in head injuries, decreased C02 results in swelling in head, If cause too much vasoconsriction brain could become hypoxic. patient disease process pharmacological therapy` |
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What could full ventilation support lead to?
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to apathy. Some clincians go for partial support
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What's partial ventilation?
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patient ventilation share the work of breathing. patient can trigger the machine or can spontaneously breathe
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What are some indications of partial ventilation?
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improves patient comfort
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Most patients are on partial or full ventilatory support
true or false? |
true
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What changes during ventilation?
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physiological pressure
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What does the Quirass ventilator do?
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mimics spontaneous breathing
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What are indications for Quirass ventilation?
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chronic neuromuscular disease
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What are advantages of Quirass ventilator?
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no need for artificial airway, easy to operate
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Disadvantages of Quirass ventilator?
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difficulty to reach patient
difficulty maintaining vent due to leaks when entire body is exposed to negative pressure. a lot blood pools in abd, reduces venous return to hear, decreased cardiac output |
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Beneficial effects of positive pressure physiological effects?
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improve oxygenation
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Anatomical shunt?
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2-5 % due to heart and lungs
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What's the formula to find shunts?
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QS/QT=Cc02-Ca02/Cc02-Cv02
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What is the QS/QT amount that can indicate to put patient on ventilator?
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20%
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What causes shunts?
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congenital heart defect, capillary, ARDS, pneumonia, atlectasis because alveoli fills with fluids and blood pressure.
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What's relative shunt?
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secretions and positive pressure ventilation. Absolute shunt doesn't respond to 02. refers to vent to profusion shunt.
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What's the cause of a relative shunt?
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pulmonary secretions, positive pressure ventilation
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How can you improve FI02?
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increase FI02, increase PA02, increased pressure gradient, can improve diffusion
increase arterial 02 content decreased shunt-must recruit collapsed alveoli and PEEP increase Ti, allows to extend diffusion Reverse I:E ratio |
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How can you improve ventilation?
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by increasing minute volume
RR 10-12 b/m |
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What are some detrimental effects of positive pressure ventilation?
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V/Q imbalances
VD/Vt space-ventilation but no blood flow e.g. of VD is pulmonary embolism (blood clot) |
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What percent of VD/Vt ratio is an indicator to mechanically ventilate a patient?
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60%
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What are some general causes for VD/Vt ratio?
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rapid shallow index
COPD pulmonary embolus positive pressure ventilation |
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Causes of patient ventilator desynchronize?
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patient neeeds more air
increased WOB as a result of inappropriately set RR Vt |
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How to fix patient ventilator desynchronize?
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can increase flow rate
vent rate can sedate the patient |
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When can atlectasis occur on ventilated patient?
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in of PPV with unweaning Vt for long period of time, will develop atlectasis.
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How can you prevent atlectasis on a mech. vent patient?
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need to add PEEP or increase PEEP
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How can you tell if atlectasis is present?
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if A-a gradient is increased, most likely have a shunt
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What are some clinical signs of atlectasis?
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decreased PaC02
decreased breath sounds increased A-a 02 gradient increased alveolar pressure because trying to open them increase PIP/volume vent decrease Vt and pressure ventilation decreased static compliance increased PF ratio <300 decreased lung expansion |
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What is normal PF ratio?
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>400 is normal
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What are some corrective actions to fix or prevent atlectasis?
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add PEEP
increase Vt up to 12-15 ml/kg add a sigh |
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What could be some causes of increased WOB?
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trigger variable
PIP incorrectly Vt patient could have decreased RAW, comliance |
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What are some renal effects?
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reduce urinary output from 30-50%
can be in relation indirectly to positive pressure ventilation ADH hormone released by pituitary gland |
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What is air trapping (auto PEEP)
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result of incomplete exhalation, insufficient inspiratory time
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How can auto PEEP be corrected?
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give pt longer time to exhale
decreased Vt increased inspiratory flow decreased RR then increased Te |
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Rule for COPD patientsr
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apply external PEEP, increase to 80% of auto PEEP, it raises the baseline and changes the trigger effort to trigger machine
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Ventilator induced lung injury is due to what?
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excessive positive pressure or volume
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Why can high ventilation pressures can produce high distending volumes leading to over inflation of lungs?
What can it cause? |
due to true alveoli
ACI and/or pneumothorax, pneumomediastinum, subcutaneous emphysema, and tissue damage with out rupture due to over inflation (barreltrauma) |
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What's derecruitment?
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alveolar collapse at the end of exhalation. Repeated opening and closing of the alveoli does as much harm as overinflating.
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What are some factors in lung disease?
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ARDS-massive non uniform lung disease
PEEP-if use high levels o PEEP emphysema large Vt increased airway pressure |
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What can cause Auto peep?
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increased FI02's
infection rt main intubations |
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What else can cause autopeep
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insufficient Te
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Where is peak pressure recorded?
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under dynamic pressure
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Why is PIP required?
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to overcome RAW and inflate the alveoli
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What's plateau pressure?
Where is it measured? |
pressure needed to inflate alveoli.
under no flow conditions |
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How high should plateau pressure be?
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less than or equal to 30
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Why do you need to put inspiratory hold for 5 seconds?
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to achieve pressure time graph
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What is the difference between peak and plateau pressure?
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RAW
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What's the formula for RAW?
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PIP-Plateau/Flow(L/S)=40-25/60=15/1
60/60=1 |
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What's normal RAW?
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0.6-2.4 cmH20
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ET tube RAW?
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0.6 H20 cm L/S
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How do you treat RAW?
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suction
give bronchodilator |
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If volume increases what will also increased and why?
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PIP because it takes more pressure if minute volume, deliver present volume. will overdistend alveoli and cause damage
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What's the relationship between PaCO2 and volume?
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increased volume, PcO2 will decrease, decreased volume Pa02 increase (may not damage the lung)
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What's another factor that could damage the lung?
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increased alveloar volume
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What are some signs and symptoms of barotrauma?
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arrhythmia
increased PIP (volume ventilation) |
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What are 2 loops?
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pressure volume
flow volume |
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What's a duck bill?
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means overinflation on volume pressure graph
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