Worsening lung compliance during pressure-controlled ventilation would cause which of the ...

(Answer to Q. 1)  ANS: C
During pressure-controlled ventilation, the delivery of the volume varies according to the charac-teristics of the lungs. Worsening lung compliance is indicative of stiffening lungs. This would cause less volume to be delivered with the same set pressure.

(Answer to Q. 2)  ANS: A
During volume-controlled ventilation, the peak inspiratory pressure generated by the delivery of the volume varies according to the characteristics of the lungs. Improving compliance makes it easier to deliver a volume, decreasing the pressure generated in the lungs.

(Answer to Q. 3)  ANS: C
The scalar shows a pressure overshoot owing to the rapid flow rate at the very beginning of in-spiration. Adjusting the slope of the pressure and flow curves can change the rate of gas delivery at the very beginning of inspiration. This tapers the curves slightly until they reach their maximum value. Decreasing the pressure setting may alleviate the overshooting problem, but it does not provide the same level of assistance to the patient. Inspiratory time and volume are controlled by the patient in pressure-support ventilation and cannot be adjusted.

(Answer to Q. 4)  ANS: C
During pressure-controlled ventilation, the delivery of the volume varies according to the charac-teristics of the lungs. Improving compliance makes it easier to deliver a volume with the same set pressure.

(Answer to Q. 5)  ANS: B
During volume-controlled ventilation, the peak inspiratory pressure generated by the delivery of the volume varies according to the characteristics of the lungs. Worsening lung compliance is in-dicative of stiffening lungs. This would cause more pressure to be generated during the delivery of a set volume.

(Answer to Q. 6)  ANS: B
The sine-like flow waveform begins at zero and reaches the maximum inspiratory flow in the middle of inspiration. It then tapers down to zero.