Low band
<26 points
Original-cohort PPC incidence: 1.6%
The lowest observed-risk band in the original validation cohort. Lower observed risk does not mean no risk.
Perioperative pulmonary risk assessment
ARISCAT Calculatorfor postoperative pulmonary risk
Calculate the original seven-item ARISCAT score with each point shown, the validation-cohort risk band explained plainly, and clear limits on what the result can—and cannot—tell you.
7 original inputsTransparent point breakdownBounded clinical interpretation
Educational clinical decision support. ARISCAT is a preoperative risk-stratification tool for adult surgical patients. It is not an individualized PPC probability, a surgical clearance decision, or a reason by itself to proceed with, delay, or cancel surgery.
Seven-item perioperative score
Calculate the original ARISCAT score
Every point assignment and the original validation-cohort risk band stay visible. Use preoperative clinical information and the planned procedure.
Patient factors
Enter measured preoperative information
Recent respiratory history
Respiratory infection within the past month
Select whether a respiratory infection was present during the month before surgery.
Procedure factors
Select the planned procedure details
Expected procedure duration
Emergency procedure
Calculated locally in your browserNo patient data uploadedEvery point assignment displayed
Original Canet model
ARISCAT scoring table
Add the points from all seven inputs. The original score has a possible range from 0 through 123. This calculator preserves the original thresholds and does not substitute related measures.
| Component | Lower category | Middle category | Higher category |
|---|---|---|---|
| Age | ≤50: 0 | 51–80: 3 | >80: 16 |
| Resting preoperative SpO₂ | ≥96%: 0 | 91–95%: 8 | ≤90%: 24 |
| Respiratory infection in past month | No: 0 | Yes: 17 | — |
| Preoperative hemoglobin | >10 g/dL: 0 | ≤10 g/dL: 11 | — |
| Surgical incision | Peripheral: 0 | Upper abdominal: 15 | Intrathoracic: 24 |
| Expected procedure duration | <2 h: 0 | 2–3 h: 16 | >3 h: 23 |
| Emergency procedure | No: 0 | Yes: 8 | — |
What the score means
Risk bands are context—not a verdict
ARISCAT groups observed complication incidence in the original validation cohort. It is most useful when it turns a set of perioperative features into a visible prompt for appropriate planning and discussion.
Intermediate band
26–44 points
Original-cohort PPC incidence: 13.3%
Higher observed complication incidence than the low band. Use it to make the perioperative discussion and plan explicit.
High band
≥45 points
Original-cohort PPC incidence: 42.1%
Substantially higher observed complication incidence in the original cohort. Prompt thorough patient-specific planning, not automatic cancellation.
Do not treat an ARISCAT band as an individual probability. Calibration can vary across populations and settings. The displayed percentages are preserved from the original validation cohort so the result remains traceable to its source.
Use it well
A prompt for planning, not a clearance stamp
Use the score after the clinical history, examination, and planned procedure are known. A higher band can prompt review of active respiratory symptoms or infection, anemia, oxygenation, smoking, functional status, comorbidities, procedure timing and invasiveness, anesthesia technique, lung-protective strategy, analgesia, monitoring, early mobilization, and postoperative respiratory support planning. The appropriate response depends on the patient and local pathway.
Important boundaries
- ARISCAT does not replace clinician judgment, anesthesia evaluation, or surgical decision-making.
- It does not capture every relevant variable, including all comorbidities, frailty, procedure specifics, gas exchange, or trajectory.
- Do not use it to diagnose pulmonary disease or predict a particular complication.
- Urgent symptoms or clinical deterioration need direct clinical evaluation, not a calculator result.
Frequently asked questions
ARISCAT calculation and interpretation
What is the ARISCAT score?
ARISCAT is a seven-item preoperative score developed to stratify observed postoperative pulmonary complication (PPC) incidence in surgical cohorts. It combines age, resting preoperative oxygen saturation, respiratory infection during the prior month, preoperative hemoglobin, incision, expected procedure duration, and emergency surgery.
What counts as a postoperative pulmonary complication in ARISCAT?
The original composite included respiratory infection, respiratory failure, bronchospasm, atelectasis, pleural effusion, pneumothorax, and aspiration pneumonitis occurring within seven postoperative days. A score does not identify which complication will occur.
What are the ARISCAT risk bands?
In the original validation cohort, scores below 26, 26–44, and 45 or more were labeled low, intermediate, and high. Observed PPC incidences were 1.6%, 13.3%, and 42.1%, respectively. Those values describe groups in that study; they are not personalized probabilities.
Is an ARISCAT score good or bad?
It is more useful to describe the result as a lower or higher observed-risk band than as good or bad. A low score is not zero risk, and a high score is not an automatic reason to cancel surgery. The result should lead to patient-specific perioperative planning with the care team.
Which oxygen saturation should I enter?
Enter the measured resting preoperative SpO₂ used in the clinical assessment. Do not substitute an estimated value. The original score uses categories of ≥96%, 91–95%, and ≤90%. Oxygen use and other clinical context still matter even though they are not separate ARISCAT inputs.
Does ARISCAT apply to every patient and procedure?
No score applies perfectly everywhere. Use clinical judgment, current symptoms, functional status, procedure specifics, comorbidities, frailty, gas exchange, medication and smoking history, urgency, and local perioperative pathways. Do not use ARISCAT as a diagnosis, treatment order, or isolated clearance decision.
Evidence base
Primary study, validation, and perioperative context
Evidence and links reviewed September 22, 2026. The calculator implements the original ARISCAT point thresholds and shows the original validation-cohort incidence values without presenting them as personalized prediction.
Canet et al. — Prediction of postoperative pulmonary complications in a population-based surgical cohortOriginal prospective development and external validation study defining the seven ARISCAT variables, point values, score bands, and cohort incidences.Huang et al. — External validation of the ARISCAT score (British Journal of Anaesthesia, 2025)Contemporary external validation evaluating ARISCAT discrimination and calibration in a large surgical cohort.Smetana et al. — Comprehensive Strategies for Preoperative Pulmonary Risk Evaluation and ManagementRecent review of pulmonary risk evaluation, optimization, and perioperative planning; emphasizes integrating scores with clinical assessment.Odor et al. — Perioperative interventions for prevention of postoperative pulmonary complicationsSystematic review of perioperative strategies and the importance of multicomponent, patient-specific planning rather than score-only decisions.
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