RRT RRT MCQ 5

Question 1

A 70 kg patient on volume control ventilation has a tidal volume of 500 mL, rate of 14, I:E ratio of 1:2, and peak flow of 60 L/min. What is the inspiratory time?

Accepted Answer

0.50 seconds

Answer

Inspiratory time = tidal volume (L) ÷ peak flow (L/s) = 0.5 L ÷ (60/60 L/s) = 0.5 seconds.

Question 2

In a patient with status asthmaticus on mechanical ventilation, auto-PEEP is detected at 12 cmH2O. The BEST immediate intervention is:

Accepted Answer

Decrease tidal volume and respiratory rate to allow more expiratory time

Answer

Reducing rate and tidal volume lengthens expiratory time, allowing trapped gas to exhale and reducing dynamic hyperinflation and auto-PEEP.

Question 3

A patient's spontaneous breathing trial (SBT) is terminated early. Which finding is the MOST valid reason to stop the trial?

Accepted Answer

Rapid shallow breathing index (RSBI) of 120

Answer

An RSBI (f/VT) ≥105 predicts SBT failure; a value of 120 indicates rapid, shallow breathing pattern consistent with respiratory muscle fatigue.

Question 4

Which finding confirms tracheal (not esophageal) intubation after orotracheal intubation?

Accepted Answer

Continuous colorimetric end-tidal CO2 detection over 6 breaths

Answer

Continuous colorimetric or capnographic ETCO2 detection persisting over ≥6 breaths is the gold-standard confirmation of tracheal intubation.

Question 5

A patient with pulmonary hypertension requires inhaled nitric oxide (iNO) therapy. The primary mechanism of action is:

Accepted Answer

Selective pulmonary vasodilation by activating guanylate cyclase in vascular smooth muscle

Answer

iNO diffuses into pulmonary vascular smooth muscle, activates soluble guanylate cyclase, raises cGMP, and causes selective pulmonary vasodilation without systemic effects.

RRT Exam Practice Test

RRT Exam Practice Test

RRT RRT MCQ 5