A Patient Is Receiving Mechanical Ventilation with a Fractional Inspired

question 25

Multiple Choice

A patient is receiving mechanical ventilation with a fractional inspired oxygen (FɪO₂) of 0.85 and a positive end-expiratory pressure (PEEP) of 5 cm H₂O.His arterial partial pressure of oxygen (PₐO₂) is 68 mm Hg,arterial oxygen saturation (SₐO₂) is 88%,and partial pressure of end-tidal carbon dioxide (PₑₜCO₂) is 32 mm Hg.Over the next few minutes his PEEP is titrated resulting in the following data:
$\begin{array} { | l | l | l | l | l | } \hline \text { Time } & \mathrm { F } _ { 1 } \mathrm { O } _ { \mathbf { 2 } } & \begin{array} { l } \mathrm { PEEP } ( \mathrm { cm } \\\left. \mathrm { H } _ { \mathbf { 2 } } \mathrm { O } \right) \end{array} & \mathrm { S } _ { \mathrm { P } } \mathrm { O } _ { \mathbf { 2 } } ( \% ) & \mathrm { P } _ { \mathbf { z t } } \mathrm { CO } _ { \mathbf { 2 } } ( \mathrm { mm } \mathrm { Hg } ) \\\hline 0600 & 0.85 & 5 & 88 & 30 \\\hline 0630 & 0.85 & 8 & 88 & 30 \\\hline 0650 & 0.85 & 10 & 90 & 32 \\\hline 0720 & 0.80 & 12 & 93 & 34 \\\hline 0740 & 0.80 & 15 & 90 & 25 \\\hline\end{array}$
At 0740 the single-breath carbon dioxide (SBCO₂) curve shifted to the right.What action should the respiratory therapist take at this time?

• A) Increase the FɪO₂ to 0.90.
• B) Reduce the set tidal volume.
• C) Continue to increase the PEEP.
• D) Reduce the PEEP to 12 cm H₂O.

---

Definitions:

Fixed Cost

Any cost that does not depend on the firms’ level of output. These costs are incurred even if the firm is producing nothing. There are no fixed costs in the long run.

Marginal Costs

Marginal Costs involve the additional expenses incurred from the production of one extra unit of a product or service.

Total Variable Cost

the sum of all costs that vary with the level of production, such as materials and labor directly involved in manufacturing.

Total Fixed Costs

The sum of all consistent, non-variable expenses a company must pay, regardless of its level of production.