Anesthesiology
Medical Calculator

Recruitment to Inflation Ratio

Characterize lung recruitability to personalize PEEP. Adapted from an algorithm developed by The Toronto Centre of Excellence in Mechanical Ventilation (CoEMV).

Author / Source: Benjamin Mammon, MD Candidate

1
cmH2O

Airway closure = lower inflection point during a slow-flow (quasi-static) pressure-volume curve. Use the technique described in <a href="https://vimeo.com/316788443">this video</a> to measure airway opening pressure (AOP).

2
cmH2O

To test recruitability the PEEP must be changed from a higher to a lower level (ideally by 10 cmH₂O). Example: 15 cmH₂O to 5 cmH₂O. <br/><br/> <b>Volume Assist Control</b> should be used. <br/><br/> Reduce the respiratory rate to 6-8 bpm to ensure enough time to exhale when PEEP is dropped. <br/><br/> Perform the following steps (see <a href="https://vimeo.com/316708822">recruitability maneuver reference video<a/> for a demonstration): <br/><br/> 1. Input the exhaled volume at high PEEP with the respiratory rate set to 6-8 bpm<br/><br/> 2. Change to lower PEEP (do not do a gradual decrease), <b>observe the exhaled volume when the PEEP changes from high to low</b><br/><br/> 3. Perform an inspiratory pause (at low PEEP) and input the plateau pressure from the ventilator.

3
mL

To test recruitability the PEEP must be changed from a higher to a lower level (ideally by 10 cmH₂O). Example: 15 cmH₂O to 5 cmH₂O. <br/><br/> <b>Volume Assist Control</b> should be used. <br/><br/> Reduce the respiratory rate to 6-8 bpm to ensure enough time to exhale when PEEP is dropped. <br/><br/> Perform the following steps (see <a href="https://vimeo.com/316708822">recruitability maneuver reference video<a/> for a demonstration): <br/><br/> 1. Input the exhaled volume at high PEEP with the respiratory rate set to 6-8 bpm<br/><br/> 2. Change to lower PEEP (do not do a gradual decrease), <b>observe the exhaled volume when the PEEP changes from high to low</b><br/><br/> 3. Perform an inspiratory pause (at low PEEP) and input the plateau pressure from the ventilator.

4
mL

To test recruitability the PEEP must be changed from a higher to a lower level (ideally by 10 cmH₂O). Example: 15 cmH₂O to 5 cmH₂O. <br/><br/> <b>Volume Assist Control</b> should be used. <br/><br/> Reduce the respiratory rate to 6-8 bpm to ensure enough time to exhale when PEEP is dropped. <br/><br/> Perform the following steps (see <a href="https://vimeo.com/316708822">recruitability maneuver reference video<a/> for a demonstration): <br/><br/> 1. Input the exhaled volume at high PEEP with the respiratory rate set to 6-8 bpm<br/><br/> 2. Change to lower PEEP (do not do a gradual decrease), <b>observe the exhaled volume when the PEEP changes from high to low</b><br/><br/> 3. Perform an inspiratory pause (at low PEEP) and input the plateau pressure from the ventilator.

5
cmH2O

To test recruitability the PEEP must be changed from a higher to a lower level (ideally by 10 cmH₂O). Example: 15 cmH₂O to 5 cmH₂O. <br/><br/> <b>Volume Assist Control</b> should be used. <br/><br/> Reduce the respiratory rate to 6-8 bpm to ensure enough time to exhale when PEEP is dropped. <br/><br/> Perform the following steps (see <a href="https://vimeo.com/316708822">recruitability maneuver reference video<a/> for a demonstration): <br/><br/> 1. Input the exhaled volume at high PEEP with the respiratory rate set to 6-8 bpm<br/><br/> 2. Change to lower PEEP (do not do a gradual decrease), <b>observe the exhaled volume when the PEEP changes from high to low</b><br/><br/> 3. Perform an inspiratory pause (at low PEEP) and input the plateau pressure from the ventilator.

6
mL

To test recruitability the PEEP must be changed from a higher to a lower level (ideally by 10 cmH₂O). Example: 15 cmH₂O to 5 cmH₂O. <br/><br/> <b>Volume Assist Control</b> should be used. <br/><br/> Reduce the respiratory rate to 6-8 bpm to ensure enough time to exhale when PEEP is dropped. <br/><br/> Perform the following steps (see <a href="https://vimeo.com/316708822">recruitability maneuver reference video<a/> for a demonstration): <br/><br/> 1. Input the exhaled volume at high PEEP with the respiratory rate set to 6-8 bpm<br/><br/> 2. Change to lower PEEP (do not do a gradual decrease), <b>observe the exhaled volume when the PEEP changes from high to low</b><br/><br/> 3. Perform an inspiratory pause (at low PEEP) and input the plateau pressure from the ventilator.

7
cmH2O

To test recruitability the PEEP must be changed from a higher to a lower level (ideally by 10 cmH₂O). Example: 15 cmH₂O to 5 cmH₂O. <br/><br/> <b>Volume Assist Control</b> should be used. <br/><br/> Reduce the respiratory rate to 6-8 bpm to ensure enough time to exhale when PEEP is dropped. <br/><br/> Perform the following steps (see <a href="https://vimeo.com/316708822">recruitability maneuver reference video<a/> for a demonstration): <br/><br/> 1. Input the exhaled volume at high PEEP with the respiratory rate set to 6-8 bpm<br/><br/> 2. Change to lower PEEP (do not do a gradual decrease), <b>observe the exhaled volume when the PEEP changes from high to low</b><br/><br/> 3. Perform an inspiratory pause (at low PEEP) and input the plateau pressure from the ventilator.

Results

Real-time automated computation

0/3 calculated
Recruitment to Inflation Ratio
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Lung Recruitability
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Result #3
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Clinical Parameters (0/7)
0%
Medical calculation formulas standardized according to evidence-based clinical protocols.