Technological and Procedural Proficiency Flashcards

A patient undergoing prone positioning for severe ARDS develops worsening oxygenation after 2 hours. The MOST appropriate initial action is:

Answer: Assess endotracheal tube position and secretion clearance

Endotracheal tube displacement and secretion accumulation are the most common reversible causes of oxygenation decline during prone positioning and should be assessed first.

Which parameter from an esophageal pressure catheter most directly guides PEEP titration in ARDS?

Answer: Transpulmonary pressure at end-expiration

End-expiratory transpulmonary pressure (airway pressure minus esophageal pressure) guides PEEP titration to maintain alveolar patency without overdistension.

During an arterial blood gas draw from a radial arterial line, the specimen appears bright red and the pO2 is 450 mmHg on room air. What error has most likely occurred?

Answer: Air bubble contamination

Air bubbles in an ABG sample equilibrate with atmospheric O2 (~150 mmHg), falsely elevating pO2; the bright red color and very high pO2 on room air indicate air contamination.

In high-frequency oscillatory ventilation (HFOV), oxygenation is primarily controlled by adjusting:

Answer: Mean airway pressure (mPaw)

Mean airway pressure determines alveolar recruitment and oxygenation in HFOV, while amplitude controls CO2 elimination.

A critically ill patient requires extracorporeal membrane oxygenation (ECMO). The circuit shows a sudden drop in pump flow with normal RPM. The MOST likely cause is:

Answer: Hypovolemia causing inlet cannula collapse (chatter)

Decreased pump flow at constant RPM with visible cannula vibration (chatter) indicates inadequate venous return due to hypovolemia or cannula malposition.

Which complication is MOST specific to femoral vein central venous catheter placement compared to subclavian placement?

Answer: Higher infection and thrombosis rates

Femoral CVCs carry significantly higher rates of deep vein thrombosis and catheter-related bloodstream infections compared to subclavian sites.

During point-of-care ultrasound assessment for pneumothorax, which finding CONFIRMS the absence of pneumothorax at the examined site?

Answer: Lung sliding sign

Lung sliding (movement of visceral against parietal pleura during respiration) confirms pleural apposition and excludes pneumothorax at the probe location.