Clinical Variable | Canet J et al. 2010 | Gupta H et al. 2011 | Arozullah AM et al. 2000 | LAS VEGAS investig. 2017 | Bauman ZM et al. 2015 [16] | Kor DJ et al. 2011 [15] |
---|---|---|---|---|---|---|
Patient dependent | ||||||
 Age | Yes | Yes | Yes | Yes | No | Yes |
 Dependent functional status | No | Yes | Yes | No | No | No |
 ASA score | No | Yes | No | Yes | No | No |
 Chronic obstructive pulmonary disease | No | Yes | Yes | No | No | Yes |
 Impaired sensorium | No | No | Yes | No | No | No |
 Cerebrovascular accident | No | No | Yes | No | No | No |
 Preoperative SpO2 | Yes | No | No | Yes | No | No |
 Transfusion > 4 units prior surgery | No | No | Yes | No | Yes | No |
 Significant weight loss | No | No | Yes | No | No | No |
 Preoperative sepsis | No | Yes | No | No | No | No |
 Preoperative anaemia | Yes | No | No | Yes | Yes | No |
 Blood urea nitrogen level | No | No | Yes | No | No | No |
 Recent respiratory infection | Yes | No | No | No | No | No |
 Relevant alcohol intake | No | No | Yes | No | Yes | Yes |
 Smoking before operation | No | Yes | Yes | No | Yes | Yes |
 Chronic steroid use | No | No | Yes | No | No | No |
 Cancer | No | No | No | Yes | No | No |
 Obstructive sleep apnoea | No | No | No | Yes | No | No |
 Hypoalbuminemia | No | No | No | No | No | No |
 Chemotherapy | No | No | No | No | Yes | Yes |
 Diabetes mellitus | No | No | No | No | Yes | Yes |
 Acidosis | No | No | No | No | Yes | No |
 Obesity | No | No | No | No | Yes | Yes |
 FiO2 > 0.35 (or > 4 L/min) | No | No | No | No | Yes | No |
 Tachypnoea | No | No | No | No | Yes | No |
 Sepsis | No | No | No | No | Yes | No |
 Aspiration | No | No | No | No | Yes | No |
 Shock | No | No | No | No | Yes | No |
 High risk trauma | No | No | No | No | Yes | No |
 BMI | No | No | No | No | Yes | No |
 Amiodarone | No | No | No | No | Yes | Yes |
 Statins | No | No | No | No | No | Yes |
 ACE-I/ARB | No | No | No | No | No | Yes |
 Sex | No | No | No | No | No | Yes |
 Restrictive lung disease | No | No | No | No | No | Yes |
 GERD | No | No | No | No | No | Yes |
 Cirrhosis | No | No | No | No | No | Yes |
Procedure dependent | ||||||
 Elective or emergency procedure | Yes | Yes | Yes | Yes | No | No |
 Duration of surgery | Yes | Yes | Yes | Yes | No | No |
 Type of surgical procedure | Yes | Yes | Yes | No | Yes | Yes |
 Type of anaesthesia | No | No | No | Yes | No | No |
 Use of supraglottic device | No | No | No | Yes | No | No |
 Desaturation | No | No | No | Yes | No | No |
 Need of vasoactive drugs | No | No | No | Yes | No | No |
 Mechanical ventilation characteristics | No | No | No | Yes | No | No |
Validation | ||||||
 Prospective external validation | Yes | No | No | Yes | No | Yes |