Question

3. 3 days later her fever continues to climb, tidal volume/rate measurements are as follows: RR 44bpm and Tidal volume 250mL. What is her Minute Volume, Alveolar minute volume, and alveolar tidal volume?

Answer 1

The patient's Minute Volume is 11 L/min, Alveolar Minute Volume is 5.05 L/min, and Alveolar Tidal Volume is approximately 115 mL.

Three days later, with a persistently elevated fever, the patient's respiratory parameters reveal a respiratory rate (RR) of 44 breaths per minute (bpm) and a tidal volume of 250 milliliters (mL).

To calculate Minute Volume (MV), the product of RR and tidal volume is determined: MV = RR × Tidal Volume = 44 bpm × 250 mL = 11,000 mL/min or 11 L/min.

Alveolar Minute Volume (AMV), representing the volume of fresh air reaching the alveoli per minute, can be estimated by subtracting the dead space ventilation from the Minute Volume.

Assuming a typical dead space of around 150 mL, the Alveolar Minute Volume is calculated as follows: AMV = MV - Dead Space Ventilation = 11,000 mL/min - 150 mL/breath × 44 bpm = 5,050 mL/min or 5.05 L/min.

Finally, Alveolar Tidal Volume (ATV) is the volume of air reaching the alveoli with each breath.

To find this, divide the Alveolar Minute Volume by the Respiratory Rate: ATV = AMV / RR = 5,050 mL/min ÷ 44 bpm = 115 mL/breath.

The patient's Minute Volume is 11 L/min, Alveolar Minute Volume is 5.05 L/min, and Alveolar Tidal Volume is approximately 115 mL.

These values provide insight into the respiratory dynamics and efficiency, crucial for assessing the patient's respiratory status and potential respiratory distress in the context of the ongoing fever.