Ventilator management Flashcards
What is tidal Volume?
VT
Air that patient breathes in during a normal minute
What is Inspiratory Reserve Volume?
IRV
Amount of air forcefully inhaled in addition to normal breath
What is expiratory reserve volume?
Amount of air forcefully exhaled after a normal breath
What is the equation for vital capacity? (VC)
VT+IRV+ERV= VC
What is residual volume?
RV
Amount of air left in respiratory tract after forceful exhalation
What is total lung capacity? (TLC)
IRV+VT+ERV+RV= TLC
What is dead space?
Surface of airway that are not involved in gas exchange
Gas exchange only occurs in the alveoli
Dead space formula: 2 ml/kg
Where are the central chemo receptors located?
medulla and pons
What is the brain chemo receptor called? Response?
Central
This is a slow responding system
Response is driven by CO2 and H+ levels in the CSF
Where are the peripheral chemo receptors located?
In aortic arch and carotid bodies
What is the heart chemo receptors called? Response?
Peripheral
Body’s pulse Ox
Response driven by O2, CO2 and H+
What are some conditions of Hypoxic respiratory Failure?
ARDS, pneumonia, CHF, Asthma
Anything that inhibits getting O2
How do you treat hypoxic respiratory failure?
By increasing FIO2 and PEEP. VT and Rate will have minimal impact.
What causes hypercarbia respiratory failure?
Damage to pons or upper medulla (stroke/trauma)
Inability to remove CO2
How do you treat hypercarbia respiratory failure?
Fix by increasing VT and RR
What are some breathing patterns? (5)
Kussmaul, Cheyne-Stokes, Apneustic, Attaxic, Biots
Describe Cheyne-Stokes breathing pattern?
This is hypoperfusion of the brain
Caused by drugs, stroke, sleep apnea or heart failure
Described as a gradual deeper or faster respiration pattern followed by a period of apnea
Describe Kussmaul Respirations?
This is caused by diabetic ketoacidosis, cancers or kidney/liver failure
Deep rapid respirations
Describe Apneustic respirations?
Deep gasping inspirations
Associated with decerebrate posturing
Describe Attaxic respirations?
Complete irresgularity of breathing with irregular pauses and increase periods of apnea.
Caused by damage to the medulla secondary to trauma or stroke.
Describe Biots respirations?
Deep regular respirations with periods of apnea.
Caused by damage to the medulla secondary to CVA or trauma or pressure on the medulla secondary to brainstem herniation.
What is the normal Tidal Volume?
4-8 cc/kg IBW
How do you calculate Minute Volume? (VE)
RxVT Should be 4-8 L/min
What is the average FIO2?
0.21-1.0
What is PIP? What is the normal value?
Pressure to inflate the lung
<35
What is the PPlat? What is the normal value?
Plateau Pressure
Pressure to small airways and alveoli
<30
What does lung compliance mean?
The stretchiness of the lung
What does low compliance mean?
Stiff lung and needing higher pressure
What does high lung compliance mean?
Less stiff lung and needing lower pressure
What are the three different breaths that can be delivered on a vent?
Controlled breaths (cannot take own breath) Assisted Breaths (deliver full breaths) Support spontaneous breaths (some support but not full support)
Which setting on the vent can cause Auto peep or stacked breaths?
Volume control setting
ASV, ACV, CMV
What does volume control effect?
ETCO2
Pressure assist control is where a preset pressure is delivered. What else do you have to monitor?
Volume
Volume can change with each breath
What is SIMV mode?
Capable of delivering all three vent breaths
Synchronized intermittent mandatory ventilation
What is important to remember with COPD/Emphysema patient’s?
Set RR lower
How can you obtain what the PPLAT is?
End inspiratory hold maneuver Goal is <30
On our vent exhaled tidal volume divided by CSTAT + peep
What does high PPLAT and PIP reflect?
Decreased Lung compliance and Lung disease
-ARDS, pulmonary contusion, Pulmonary edema, Pleural effusion, tension pneumo, circumferential chest burn, massive ascites, compartment syndrome, pneumonia.
What is the normal difference between your PIP and PPLAT?
<5
What does Increases PIP and unchanged PPLAT reflect?
Increased airway resistance
-ETT occlusion, secretions/mucous, bronchospasm, kinked line
What does DOPES stand for?
Dislodged (low pressure), obstructed (high pressure), pneumothorax (high pressure), equipment, stacked breaths (high pressure)
What is Patient/vent desynchrony?
Respiratory demands not being met
Caused by inadequate sedation or pain control
Evidence of Curare cleft on ETCO2 (patient making an attempt to breath)
What is VQ ratio
Determined by nuclear study
Relation to ventilation and perfusion
What does high or low VQ reflect
Low VQ reflects respiratory failure, Low PaO2, high PaCO2
High reflects something like a PE
What is a normal V/Q ratio?
0.8 or 4/5
What pulmonary diseases show a flattened diaphragm on Chest X-Ray
COPD and Asthma
What is the treatment for Asthma?
Increase I:E ration to 1:4 Zero peep Consider Bi-Pap High flow O2 Bronchodilators EPI, Mag , steroids, IV fluids and or Ketamine Manual exhalation
What are some signs and symptoms of COPD?
Barrel chest (blue bloater) and Pink frothy sputum from emphysema.
What is a pleural effusion?
Fluid in pleural space that gravitates to most dependent area
What does a chest X-Ray show in pneumonia?
Pleural effusions, lobar consolidations, patchy infiltrate’s
Right middle lobe is the most common site for consolidation
What does ARDS stand for?
Acute respiratory distress syndrome
What is ARDS?
Collection of fluid in lung’s air sacs depriving the organ’s of O2
What does the chest X-ray show on an ARDS patient?
Ground glass appearance, patchy infiltrates, bilateral diffuse infiltrates
What are some treatments for ARDS Patient’s?
Increase peep and FIO2 (peep >10)
Low Tidal volume (4cc/kg)
Increase RR (ensure adequate MV)
Where are the central chemoreceptors located?
Medulla and Pons
What is the gold standard for monitoring ventilation?
Capnography
What 2 factors influence oxygenation?
Peep and FIO2
What 2 factors influence ventilation?
Respiratory rate and tidal volume
PPLAT should be maintained less than ?
30
PIP should be maintained less than ?
35
What is the IBW calculation for both male and female?
Males: 50 kg + 2.3 kg for each inch over 5 ft
Females: 45.5 kg + 2.3 kg for each inch over 5 ft
How many minutes should you wait for serial ABG’s when making vent changes?
15 minutes