Ventilation and Perfusion: Understanding VQ Mismatch and ARDS

These flashcards cover key concepts related to ventilation and perfusion, ARDS, treatment strategies, and patient care in critical situations.

What does VQ stand for in VQ scans?

Ventilation and Perfusion.

What is the normal ventilation to perfusion ratio?

1 to 1.

What causes VQ mismatch?

Anything that negatively impacts either oxygen getting to the alveoli or blood getting to the capillaries.

What is an anatomical shunt?

A defect that allows blood to bypass oxygenation, such as a hole between the right and left ventricles.

What is the definition of ARDS?

Acute Respiratory Distress Syndrome, characterized by hypoxemia that is refractory to oxygen therapy.

What are the three phases of ARDS?

Exudative, Proliferative, and Fibrotic.

What is the hallmark characteristic of the exudative phase of ARDS?

Widespread atelectasis and interstitial edema.

What happens during the fibrotic phase of ARDS?

Permanent scarring and decreased lung compliance.

What is the purpose of PEEP in mechanical ventilation?

To prevent alveoli from fully collapsing after exhalation.

What are common complications of ARDS?

Ventilator-associated pneumonia (VAP), O2 toxicity, barotrauma, and pulmonary emboli.

What does hypoxemia during exertion indicate in ARDS patients?

That the respiratory system is unable to provide adequate oxygen during increased physical demand.

How should a patient's pH be maintained during permissive hypercapnia?

Greater than 7.2.

What is the role of ECMO in relation to ARDS?

It allows for lung rest by oxygenating the blood outside the body, making the lungs irrelevant temporarily.

What is the pulmonary capillary wedge pressure indicative of in ARDS, if less than 18?

That the patient's pulmonary edema is non-cardiogenic.

How often should sedation vacations occur for patients on mechanical ventilation?

Ideally, every day, particularly in calm hours.

What is the rationale behind early ambulation for ARDS patients?

To facilitate better lung function and secretion clearance.