Respiratory Rate, Tidal Volume, and Monitoring

Tidal volume, respiratory rate, and minute volume are important

parameters that reflect upon the patient’s clinical status and help the

physician diagnose and treat their patient. The data provided by

Linshom (RR, relative tidal volume and relative minute ventilation) in a

non – intubated patient could greatly help in ensuring patient well-being.

It must be noted that RR and TV vary from normal when patients

suffer from certain disease states. Linshom can help both monitor and

diagnose some of these conditions.


RR – respiratory rate (number of breaths per minute)

Tidal volume (TV) – volume inhaled or exhaled during quiet breathing

Minute ventilation: RR x TV for 1 minute

The additional parameters that could be measured in a pulmonary function lab:

Inspiratory Reserve Volume (IRV) – volume inhaled in excess of the TV in a deep inspiration

Expiratory Reserve Volume (ERV) – volume exhaled in excess of the TV and IRV in a deep expiration

Residual Volume (RV) – volume that remains in the respiratory tract following a deep expiration

Inspiratory Capacity (IC) = TV + IRV

Vital Capacity (VC) = IRV + TV + ERV

Functional Residual Capacity (FRC) = ERV + RV

Total Lung Capacity (TLC) = IRV + TV + ERV + RV