Mechanical Ventilation

Question 1

List some indications for mechanical ventilation

Answer 1

1. Airway protection → preventive measure
2. Cardiac arrest → life saving measure
3. Management of ICP → creation of alkalosis
   
   • vasoconstriction → dec cerebral blood flow/dec ICP
4. Airway obstruction → maintenance of patient airway
5. Surgery or trauma → general anesthesia

Question 2

List and define/describe several key mechanical ventilation vocab terms

Answer 2

1. FiO2 → fraction of inspired O2
2. Tidal volume → normal amount of air ventilated at rest (mL)
3. PEEP → positive end expiratory pressure (cmH20)
4. Flow → L/min
5. RR → breaths/min

Question 3

what are the two main types of ventilation?

Answer 3

1. Invasive
   
   • intubation of artificial airway into trachea
   • endotracheal tube, nasotracheal tube, tracheostomy
2. Non-invasive (NIV)
   
   • BiPAP or CPAP
   • last step before intubation

Question 4

what is the difference between BiPAP and CPAP?

Answer 4

1. BiPAP → Bilevel Positive Airway Pressure
   
   • whole point is to lower the pressure when someone exhales to allow more CO2 out, they have no problem breathing air in but trouble getting the air out
2. CPAP → Continous Positive Airway Pressure
   
   • think of a dog w/head out the window and breathing

Question 5

what is a tracheostomy?

Answer 5

a procedure in which an opening in the neck is made and a tube placed into the trachea below the vocal cords

used when pt is unable to be weaned from ventilator or if the airway is blocked/obstructed (tumor, traumatic injury)

Question 6

List the modes of ventilation

Answer 6

1. Volume Control (VC)
2. Pressure Control (PC)
3. Assist Control (AC)
4. Pressure regulated volume control (PRVC)
5. Synchronous intermittent mandatory ventilation (SIMV)
6. Pressure Support Ventilation
7. Volume Support (VS)
8. CPAP

Question 7

describe VC

Answer 7

Volume control

• present tidial volume is delivered at a set RR
• used when pt has no spontaneous breathing
• Peak pressures can vary depending on pts lung compliance and resistance
  
  • pressure from ventilator will increase if pt’s lung compliance reduces (stiff lung = increased resistance)
  • can lead to high pressures

Question 8

describe PC

Answer 8

Pressure control

• predetermined amount of pressure at a set rate
• ventilator determines inspiratory time
• pt has no spontaneous breathing
• PEEP used to increase arterial O2, improve lung compliance
  
  • prevents collapse, makes lungs easier to inflate

Question 9

describe AC

Answer 9

Assist Control

• delivers a specific amount of tidal volume
• forces air down into lungs
• pt or ventilator can trigger when breaths are taken
• High level of respiratory support

Question 10

describe PRVC

Answer 10

Pressure Regulated Volume Control

• combines pressure and volume controlled ventilation
• preset tidal volume is delivered at a set rate, but with lowest possible pressure
• Helps prevent barotrauma

Question 11

describe SIMV

Answer 11

Synchronous intermittent mandatory ventilation

• used to assist pts who have some, but not sufficient breathing
  
  • pts can breathe in between each machine assisted breath
• Used for weaning
• Delivers certain number of breaths in coordination w/respiratory effort of pt
• does have increased work of breathing

Question 12

describe Pressure Support Ventilation

Answer 12

• small amount of pressure occurs on inspiration
• pt initates all breahts
  
  • assists pt in making a spontaneous breath
• delivers a specific pressure
• ventilator assists, but pt regulates the RR and tidal volume

Question 13

describe VS

Answer 13

Volume support

• tidal volume and PEEP are set
• pt initiates breathing
• ventilator delivers support in proportion to pt’s inspiratory effort and target volume

Question 14

T/F: CPAP is often synonymous w/spontaneous breathing trial

Answer 14

TRUE

Question 15

when looking at a ventilator what do PT’s care/need to know?

Answer 15

1. the mode the ventilator is in
2. RR
3. FiO2
4. PEEP

Question 16

what are the 3 main sedative drugs a pt on mechanical ventilation may be on?

Answer 16

1. Propofol
2. Precedex
3. Fentanyl

Question 17

what does a red alarm mean? Yellow alarm?

Answer 17

1. Red alarm
   
   • high pressure
   • circuit disconnected
   • apnea
2. Yellow alarm
   
   • low tidal volume
   • high RR
   • low minute ventilation
   • low inspiratory pressure

Question 18

List the 5 major factors to consider during weaning?

Answer 18

1. Respiratory demand and ability of NMSK system to cope w/O2 demand
2. Oxygenation
3. CV performance
4. Psychological factors
5. Adequate rest and nutrition

Question 19

List weaning signs of distress

Answer 19

1. Tachypnea >30 breaths/min
2. Decreased pH <7.25-7.30 w/increased PaCO2
3. Paradoxical breathing patterns
4. O2 saturation <90%
5. HR change of >20 bpm
6. BP change >20 mmHg
7. Agitation, panic, diaphoresis, cyanosis, angina, or arrhythmias

Question 20

where should a pt be scored on the Richmond Agitation Sedation Scale for us to work with them?

Answer 20

-1 and -2 but if we can get to 0 that’s even better

Question 21

list contraindications to PT regarding mechanical ventilation

Answer 21

1. comatose, unresponsive, does not follow commands
2. severe agitation/combativeness
3. PEEP > 10cm H20 or FiO2 > 0.6
4. Uncontrolled active bleeding

Question 22

what are some mechanical ventilation complications

Answer 22

prolonged vent support may lead to:

1. skin breakdown (decubitus ulcers)
2. Joint contractures
3. Deconditioning

Question 23

list some mechanical ventilation implications for acute care PT

Answer 23

1. AROM
2. Resistive therapeutic exercises
3. Aerobic activities (OH presses, boxing)
4. Bed mobility → rolling
5. Reaching activities w/emphasis on trunk rotation
6. Head and neck therapeutic exercises and positioning - extensors
7. Diaphragmatic breathing