A patient receiving mechanical ventilation has an exhaled tidal volume (Vᴛ)of 500 mL and a positive end expiratory pressure setting (PEEP)of 5 cm H₂O.Patient-ventilator system checks reveal the following data:
$$\begin{array} { | l | l | l | l}
\hline \text { Time } & \text { PIP } \left( \mathrm { cm } \mathrm { H } _ { 2 } \mathbf { 0 } \right) & \mathrm { P } _ { \text {platen } } \left( \mathrm { cm } \mathrm { H } _ { \mathbf { 2 } } \mathbf { O } \right) \
\hline 0600 & 27 & 15 \
\hline 0800 & 29 & 15 \
\hline 1000 & 36 & 13 \
\hline
\end{array}$$
The respiratory therapist should recommend which of the following for this patient?
1)Tracheobronchial suctioning
2)Increase in the set tidal volume
3)Beta adrenergic bronchodilator therapy
4)Increase positive end expiratory pressure

Question

A patient receiving mechanical ventilation has an exhaled tidal volume (Vᴛ)of 500 mL and a positive end expiratory pressure setting (PEEP)of 5 cm H₂O.Patient-ventilator system checks reveal the following data:
$$\begin{array} { | l | l | l | l} 
\hline \text { Time } & \text { PIP } \left( \mathrm { cm } \mathrm { H } _ { 2 } \mathbf { 0 } \right) & \mathrm { P } _ { \text {platen } } \left( \mathrm { cm } \mathrm { H } _ { \mathbf { 2 } } \mathbf { O } \right) \
\hline 0600 & 27 & 15 \
\hline 0800 & 29 & 15 \
\hline 1000 & 36 & 13 \
\hline
\end{array}$$
The respiratory therapist should recommend which of the following for this patient?
1)Tracheobronchial suctioning
2)Increase in the set tidal volume
3)Beta adrenergic bronchodilator therapy
4)Increase positive end expiratory pressure

Quizplus · Accepted Answer

Calculate the transairway pressure (Pᴛᴀ)by subtracting the plateau pressure from the peak inspiratory pressure.Analyzing the Pᴛᴀ will show any changes in the pressure needed to overcome airway resistance.Analyzing the Pₚₗₐₜₑₐᵤ will demonstrate any changes in compliance.The Pₚₗₐₜₑₐᵤ remained the same for the first two checks and then actually dropped at the 1000-hour check.Analyzing the Pᴛᴀ,however,shows a slight increase between 0600 and 0800 (from 12 to 14 cm H₂O)and then a sharp increase to 23 cm H₂O at 1000.Increases in Pᴛᴀ signify increases in airway resistance.Airway resistance may be caused by secretion buildup,bronchospasm,mucosal edema,and mucosal inflammation.Tracheobronchial suctioning will remove any secretion buildup,and a beta adrenergic bronchodilator will reverse bronchospasm.Increasing the tidal volume will add to the airway resistance according to Poiseuille's law.Increasing the PEEP will not address the root of this patient's problem; the patient's compliance is normal.

A Patient Receiving Mechanical Ventilation Has an Exhaled Tidal Volume