ARISCAT Score

ARISCAT Calculator

7 Pre-operative Risk Factors

Age (years)

Pre-operative SpO₂ (%)

Respiratory infection in last month (URTI/LRTI)

Pre-operative anaemia (Hb < 10 g/dL)

Surgical site

Duration of surgery

Emergency procedure

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ARISCAT Score (max 123)

Risk Categories

ARISCAT Score	Risk Group	PPC Rate	Action
< 26	Low	1.6%	Standard perioperative care
26–44	Intermediate	13.3%	Lung-protective ventilation; physio input; consider HDU
≥ 45	High	42.1%	Multidisciplinary pre-op review; maximise pre-op fitness; ICU availability

PPC rates from Canet 2010 derivation/validation cohort. Real-world rates may vary by institution, surgical technique, and patient population.

PPCs captured in the ARISCAT study include:

Respiratory failure — PaO₂ <60 mmHg on air or SpO₂ <90% requiring O₂
Respiratory infection — new fever + antibiotic requirement + radiological infiltrate
Pleural effusion — clinical/radiological
Atelectasis — radiological
Pneumothorax
Bronchospasm — requiring treatment
Aspiration pneumonitis

Pre-operative window: Complete ARISCAT at pre-assessment clinic (days to weeks before surgery) to allow time for risk modification.
SpO₂ measurement: Measure room air SpO₂. If <96%, screen for undiagnosed respiratory disease. A pre-op SpO₂ ≤90% carries the highest single-factor weight (24 points) — this patient should be seen by a respiratory physician before elective surgery.
Respiratory infection: Delay elective surgery by at least 4–6 weeks after resolution of URTI or LRTI.
Anaemia: Pre-operative haemoglobin <10 g/dL should trigger patient blood management — oral iron, IV iron, erythropoietin as appropriate.
Surgical site: Intrathoracic (24 pts) and upper abdominal (15 pts) surgery carries the highest site-related risk. Regional anaesthesia and minimally invasive approaches reduce risk.
Interventions for high-risk patients: Incentive spirometry pre-op; CPAP post-op; early mobilisation; respiratory physiotherapy; lung-protective ventilation strategies intraoperatively.

Canet J, et al. Prediction of postoperative pulmonary complications in a population-based surgical cohort. Anesthesiology. 2010;113(6):1338–1350.
Mazo V, et al. Prospective external validation of a predictive score for postoperative pulmonary complications. Anesthesiology. 2014;121(2):219–231.