Critical Care Flashcards
Positive-pressure ventilation is associated with what physiological changes?
- reduce cardiac output
- impair hemodynamic monitoring
- gastrointestinal stress ulcerations
- decreased splanchnic perfusion
- gastrointestinal hypomotility
- fluid retention
- acute renal failure
- increased intracranial pressure
- inflammation
- disordered sleep
What are the two types of respiratory failure and what are they from? Which one is more common in surgical patients?
Type 1 (hypoxic) respiratory failure = abnormal gas exchange at the alveolar level
Type 2 (hypercapneic) = unable to eliminate carbon diaoxide adequately
Type 1 is more common in surgical patients due to atelectasis (alveoli in periphery collapse –> pulmonary shunt)
How do you correct hypercarbia on the ventilator? How do you correct decreased oxygenation?
Correct hypercarbia by INCREASING respiratory rate or tidal volume
Increase oxygenation by increasing FIO2 or PEEP
For ARDS, what is low tidal volume ventilation
TV that is 4-8 mL/kg predicted body weight
What is the definition of prolonged mechanical ventilation? What is it’s associated 1-year mortality?
> 21 days of mechanical ventilation
1-year mortality = 40-60%
What are two ways to measure readiness of extubation? Define each and what is your goal for each.
1) rapid shallow breathing index (RSBI) = ratio of respiratory frequency to tidal volume. Increased probability of successful weaning if RSBI is < 105 breaths/min/L.
2) Negative Inspiratory force (NIF) = maximum inspiration against an occluded airway (assesses respiratory muscles). -30cmH20 is predictive of extubation success in adults. Goal is < 10cm H20 variability between multiple inspiratory efforts
What are the components of the ARDS Net protocol?
1) Low tidal volume ventilation = 4-6cc/kg of predicted body weight
2) PEEP > 5cm H20 (avoids end-expiration collapse)
3) Plateau pressure < 30cm H20
4) PaO2 goal 55 to 80mmHg
5) SpO2 88 to 95%
6) pH goal 7.3 to 7.45
