CROP Weaning Index
CROP weaning index (Yang & Tobin 1991) = [dynamic compliance x PImax x (PaO2 / PAO2)] / respiratory rate; an index >= 13 mL/breath/min favors successful extubation.
Open the calculator → Runs in your browser. Data leaves only if you deliberately send a problem report from the interactive tool.
Example
- Dynamic compliance
- 50 mL/cmH2O
- Maximal inspiratory pressure PImax
- 30 cmH2O
- PaO2
- 80 mmHg
- FiO2
- 0.4
- PaCO2
- 40 mmHg
- Respiratory rate
- 20 breaths/min
Result: CROP index 25.2 mL/breath/min — favors extubation (>= 13).
The tool opens with these values already filled in. Replace them with your own.
What the result means
- >= 13
- Favors successful extubation.
- < 13
- Below the weaning threshold ([Cdyn x PImax x (PaO2/PAO2)] / RR). A weaning predictor, not a diagnosis.
What you enter
- Dynamic compliance
- Maximal inspiratory pressure PImax (magnitude)
- PaO2
- FiO2 (fraction, 0.21-1.0)
- PaCO2
- Respiratory rate
How this is calculated
Yang KL, Tobin MJ. A prospective study of indexes predicting the outcome of trials of weaning from mechanical ventilation (CROP index). N Engl J Med. 1991;324(21):1445-1450. Read the source ↗
A reference and educational tool. Not medical, legal, or financial advice, and not a substitute for clinician judgment.