Chapter 4 - Establishing the Need for Establishing Mechanical Ventilation

Question 1

What are the 3 definitions of ARF?

Answer 1

• Inability to maintain adequate O2 uptake (PaO2 or CaO2)
• Inability to adequately eliminate CO2
• Inability to maintain acceptable ABG’s

Question 2

What are the 2 types of ARF?

Answer 2

Type 1 - Hypoxemic

Type 2 - Hypercarbic w/ some Hypoxemia

Question 3

Causes of Hypoxic Lung Failure

Answer 3

• Serious V/Q mismatching
• Diffusion defects
• R to L shunt
• Alveolar Hypoventilation

Question 4

Hypoxic Lung Failure Treatments

Answer 4

• Oxgen Therapy and/or CPAP

- Intubation

Question 5

What is a “Regular” Shunt?

Answer 5

Some blood is going to areas that are under ventilated

Question 6

What is a “True” Shunt?

Answer 6

NO ventilation where blood is going near a ventilator unit

Question 7

What is Refractory Hypoxemia?

Answer 7

When there is no response to an increase of oxygen

Question 8

Causes of Hypercapnic Respiratory Failure

Answer 8

• Ventilator Pump Failure (Resp. Muscles, Thoracic Cage, Nerves)
• Disorders (CNS, NMD, Disorders that increase WOB)

Question 9

Hypercapnic Respiratory Failure Treatments

Answer 9

• NIPPV

- Intubation

Question 10

In which type does Diaphoresis occurs?

Answer 10

Type II

Question 11

What occurs during Hypoxia?

Answer 11

-Tachycardia and Tachypnea

Question 12

What occurs during Hypercapnia

Answer 12

• Increased CO2
• Increased cerebral blood flow
• High levels of CO2 leading to CO2 narcosis

Question 13

What does a Traumatic Brain Injury cause within the first 24 hours?

Answer 13

Reduction of blood flow to the brain by 50%

Question 14

If patient is hyperventilating with a brain injury, what occurs?

Answer 14

Blood flow is reduced by another 50%.

75% total blood flow is cut off.

Question 15

What is our target CO2 range for TBI patients?

Answer 15

35-45 but no less than 30 mmhg

Question 16

What is given to reduce ICP for head injuries?

Answer 16

Osmotic diuretic (Mannitol)

Question 17

Why do we not hyperventilate patients with TBI for more than 24 hours?

Answer 17

Reflex will go away and the ICP will go back up

Question 18

If an ICP > 20 is sustained for 5 min, what can we do?

Answer 18

We can temporarily hyperventilate a patient between 30-35

Question 19

What drugs impair neuromuscular function?

Answer 19

All Narcotics

Question 20

What is a normal MIF and what is considered bad?

Answer 20

• Normal: -80 cmH20

- Bad: > -20 cm h20

Question 21

What is a normal VC?

Answer 21

60-80 mL/kg

Question 22

What is the VO2 percentage with normal WOB?

Answer 22

~1-4%

Question 23

What are evidences of increased WOB?

Answer 23

• Increased RR and/or depth of respirations

- VO2 increases to 35-40%

Question 24

What is the Normal and Critical values for MIF?

Answer 24

Normal: -100 to -50 cmH20
Critical: -20 to 0 cmH20

Question 25

What is the Normal and Critical values for VC?

Answer 25

Normal: 65-75 mL/Kg Critical: > 10ml per kg

Question 26

What is the Normal and Critical values for Vt?

Answer 26

Normal: 4-8 mL/Kg Critical:

Question 27

What is the Normal and Critical values for RR?

Answer 27

Normal: 12-20/min Critical: >35/min

Question 28

What is the Normal and Critical values for PEFR?

Answer 28

Normal: 350-600L/min Critical: 75-100L/min

Question 29

What is the Normal and Critical values for VD/Vt?

Answer 29

Normal: .3-.4 Critical: .6

Question 30

What are the standard criteria for Invasive Ventilation?

Answer 30

Normal Criteria: Support of pulmonary system until return to normal state, Reduce WOB, Restore Acid-Base balance, Improve O2 delivery.

Question 31

What are the alternatives to Invasive Ventilation/

Answer 31

Supplemental O2: High Flow Treatment of underlying cause NIPPV CPAP via T-piece

Question 32

What are the Absolute contraindications for NIPPV?

Answer 32

``` Absolute: Cardio-Resp. Arrest, Acute instability of other organs, Upper airway obstruction, Inability to protect airway, Inability to clear secretions, Facial/Head trauma ```

Question 33

What are the Relative contraindications for NIPPV?

Answer 33

``` Relative: Cardio-Pulmonary Instability, Inability to cooperate, copious secretions, Extreme obesity ```

Question 34

What ABG values are associated with respiratory failure?

Answer 34

pH less than 7.25 paC02 50 mmhg and rising PaO2 less than 90% of predicted.

Question 35

How do you assess if a patient has an oxygenation problem?

Answer 35

Calculate the predicted PaO2. Pa02 = 104.2 - (0.27 x age) After that, if the Patient's ABG is less than 90% of predicted. Its an oxygenation problem.

Question 36

What are causes of Hypoxemic (Type I) respiratory failure? | 5 causes

Answer 36

Serious V/Q Mismatching Diffusion Defects Right to Left Shunt (Not a true shunt because some blood goes through the pulmonary arteries) Alveolar Hypoventilation

Question 37

What are causes of Hypercapnic (Type II) Respiratory Failure? 2 main causes

Answer 37

Ventilatory Pump Failure (Respiratory Muscles, Thoracic Cage, Nerves and Nerve Centers That Control Ventilation) Disorders Leading To Ventilatory Pump Failure (CNS Disorders, Neuromuscular Disorders, Disorders That Increase WOB)

Question 38

What are signs and symptoms of Hypercapnia?

Answer 38

Increased CO2 levels - Hypercapnia Increased cerebral blood flow/vasodilation – headaches High levels of CO2 leading to CO2 narcosis Untreated could lead to acidosis – arrhythmias – death

Question 39

What is the mantra for spinal cord injuries? why?

Answer 39

C 3,4,5 keep your patient alive. C3 injuries have loss of respiratory muscles C4 and C5 injuries have the possibility of loss of voluntary muscles for respiration.

Question 40

What is the protocol for patients with a traumatic brain injury in the first 24 hours?

Answer 40

Never hyperventilate in the first 24 hours If patient is becoming hypercapnic, place patient in a Phentobarbitol coma and paralytics to decrease o2 comsumption

Question 41

what is the ABSOLUTE criteria for invasive ventilation?

Answer 41

Apnea, Acute Vent. Failure, Impending Vent. Failure, Refractory Hypoxemia

Question 42

What is the formula for Mean Arterial Pressure? | What value are you looking for?

Answer 42

(2 diastolic + 1 Systolic)/3 = MAP You want Map above 60 (low is deceased blood supply to organs) High MAP is increased Cardiac Work Load