PNA, ICU, Vent Management

Question 1

What is Plateau Pressure?

Answer 1

Plateau pressure - Pressure Applied to the Small Airways and Alveoli after Inhalation is Complete BUT Before exhalation begins

— essentially, the pressure needed to keep the lungs open at the END of INSPIRATION ( Breathing in)

Question 2

What is Peak Pressure?

Answer 2

The maximum pressure reached in the airways during mechanical ventilation at the end of inspiration.

Question 3

What is Tidal Volume?

Answer 3

Tidal volume is the amount of air delivered to the lungs with each breath by the ventilator. It’s one of the most critical settings in mechanical ventilation because it directly affects gas exchange and lung mechanics.

Question 4

Recomended Tidal Volume

Answer 4

Question 5

1. What are some causes of ⬆️ Plateau Pressures?
2. How to lower the Plateau Pressures?

Answer 5

1. Decrease Tidal Volume (Most Effective)
2. Optimize PEEP
3. Treat underlying cause
4. Prone Positioning these lung posterior pressure is relived, which improves alveolar recruitment and reduces regional overdistension

Question 6

Difference between Peak and Plateau Pressures?

Answer 6

Question 7

Answer 7

Because lowering the tidal volume more directly and safely reduces minute ventilation (VE) while maintaining patient comfort, oxygenation, and lung protection —
especially important in conditions like ARDS.

In Respiratory Alkalosis on the vent, 🥇 Reduce tidal volume (if safe), especially in ARDS. Only reduce RR if TV is already at the minimum safe level.

Question 8

What is the tidal volume target for ARDS patients on a ventilator?

Answer 8

4–6 mL/kg of ideal body weight

Question 9

Why use low tidal volumes in ARDS?

Answer 9

To prevent barotrauma and volutrauma from alveolar overdistension

Question 10

What plateau pressure should be maintained in ARDS?

Answer 10

≤ 30 cm H₂O

Question 11

What is the initial ventilator mode for ARDS?

Answer 11

Volume Assist-Control (AC-VC)

Question 12

What is the minimum acceptable pH in permissive hypercapnia for ARDS?

Why is this important ?

Answer 12

1. 7.15
2. Low tidal volumes help protect lungs to prevent barotrauma which causes hypercapnia so its permissive (we allow it on purpose)

Question 13

1. What is the ideal Plateau Pressure?
2. What if the Plateau Pressure is >30 cm H₂O, what should be done and why?
3. How does it affect Venous Return?

Answer 13

1. <30 cm H₂O
2. Reduce tidal volume by 1 mL/kg (down to minimum of 4 mL/kg) to prevent Barotrauma, Pneumothorax and Pneumomediastinum

Low pressure helps to improve venous return to the heart.

Too much pressure 🛑 pre-load/Venous return

Question 14

1. What FiO₂ should you aim for once oxygenation improves in ARDS?

2.When should Prone Positioning be considered in ARDS?

3. When should neuromuscular blockade be used in ARDS?

Answer 14

1. Titrate FiO₂ to < 60% if possible while maintaining SpO₂ > 88% (prevent over oxygenating)
2. When PaO₂/FiO₂ < 150 despite optimized vent settings
3. If patient is ventilator asynchronous or severely hypoxic despite max support

Question 15

1. What are the oxygenation goals for ARDS?
2. What PaO₂/FiO₂ ratio defines Severe ARDS?
3. What PaO₂/FiO₂ ratio defines Mild ARDS?

Answer 15

1. PaO₂ 55–80 mmHg or SpO₂ 88–95%
2. < 100 mmHg
3. 200-300 mmHg

Question 16

1. What is the issue if Peak Pressure is ⬆️ but Plateau Pressure is Normal?
2. What does ⬆️ Plateau Pressure tell you?

Answer 16

1. Peak Pressue is an Airway Resistance (mucous, bronchospams) and lung Compliance issue
2. There is a Lung Compliance Issue (ARDS)

Question 17

How do you treat a Tension Pneumothorax?

Answer 17

Immediate needle decompression (2nd intercostal space, midclavicular line) followed by chest tube placement.

Question 18

What is Pneumomediastinum and how does it differ from Pneumothorax?

Answer 18

Air in the mediastinum instead of pleural space; may occur from trauma, barotrauma, or esophageal rupture.

Question 19

What are some factors that can cause difficulty with ventilator weaning?

Answer 19

1. Fluid overload
2. Unresolved infection
3. Malnutrition
4. Hypomagnesiumsemia, Hypophosphatemia
5. Hypothyroidism
6. Inadequate mental status
7. Copious secretions
8. Upper airway lesions

Each of these factors can negatively impact the ability to successfully wean a patient from a ventilator.

Question 20

What are the strongest risk factors for CIM?

Answer 20

Systemic Corticosteroids, Neuromuscular blocking agents, and Sepsis.

Systemic corticosteroids are the strongest risk factor.

Question 21

1. When do patients usually present symptoms of CIM?
2. How do patients typically present with CIM?
3. What is usually normal?

Answer 21

1. Several days after IV steroid or paralytic agent administration
2. Flaccid Quadriparesis (proximal > distal muscles) ➕ difficulty Weaning from mechanical ventilation
3. Sensation is in tact 💆🏽‍♀️

Facial muscle weakness may also occur.

Question 22

How does BIPAP improve Pre-load?

Answer 22

The air from the machine ⬆️🫁the pressure in the chest and ⛔️the blood from Systemic Circulation entering the Heart. ♥️

Question 23

1. If both Peak and Plateau pressure ⬆️?
2. If only Peak is ⬆️?

Answer 23