Table 1.
Description of ventilatory parameters
| Parameter | Abbreviation | Units | Definition |
|---|---|---|---|
|
| |||
| A. Directly recorded parameters | |||
| Frequency of breaths | Freq | breaths/min | Rate of breathing |
| Inspiratory Time | Ti | sec | Duration of inspiration |
| Expiratory Time | Te | sec | Duration of expiration |
| End Inspiratory Pause | EIP | msec | Pause between end of inspiration start of expiration |
| End Expiratory Pause | EEP | msec | Pause between end of expiration and start of inspiration |
| Relaxation time | RT | sec | Decay of expiration to 36% maximum |
| Tidal Volume | TV | ml | Volume of inspired air per breath |
| Minute Ventilation | MV = freq × TV | ml/min | Total volume of air inspired per min |
| Peak Inspiratory Flow | PIF | ml/sec | Maximum inspiratory flow |
| Peak Expiratory Flow | PEF | ml/sec | Maximum expiratory flow |
| Expiratory flow at 50% | EF50 | ml/sec | Expiratory flow at 50% expired TV |
| Non-eupneic breathing index | NEBI | % | % of non-eupneic breaths per epoch |
|
| |||
| B. Derived parameters | |||
| Inspiratory Drive | TV/Ti | ml/sec | Central urge to inhale |
| Expiratory Drive | TV/Te | ml/sec | Central drive to exhale |
| NEBI/Frequency | NEBI/Freq | %/(b/min) | Balanced rejection index |
| Apneic Pause | AP = (Te/RT)-1 | No units | Elongated expiration |