Table 3 Postoperative pulmonary complications score

Grade 1

- Cough, dry

- Microatelectasis: abnormal lung findings and temperature > 37.5 °C without other documented cause; normal chest radiograph

- Dyspnea, not due to other documented cause

Grade 2

- Cough, productive, not due to other documented cause

- Bronchospasm: new wheezing or pre-existent wheezing resulting in a change in therapy

- Hypoxemia (SpO₂ ≤ 90%) at room air

- Atelectasis: gross radiological confirmation (concordance of 2 independent experts) plus either temperature > 37.5 °C or abnormal lung findings

- Hypercarbia (PaCO₂ > 50 mmHg), requiring treatment

Grade 3

- Pleural effusion, resulting in thoracentesis

- Pneumonia: radiological evidence (concordance of 2 independent experts) plus clinical symptoms (two of the following: leucocytosis or leucopenia, abnormal temperature, purulent secretions), plus either a pathological organism (by Gram stain or culture), or a required change in antibiotics

- Pneumothorax

- Noninvasive ventilation, strictly applied to those with all of the following: a) oxygen saturation (SpO₂) lower than 92% under supplemental oxygen; b) need of supplemental oxygen > 5 L/min; and RR ≥ 30 bpm

- Re-intubation postoperative or intubation, period of ventilator dependence (non-invasive or invasive ventilation) ≤ 48 h

Grade 4

- Ventilatory failure: postoperative ventilator dependence exceeding 48 h, or reintubation with subsequent period of ventilator dependence exceeding 48 h

Grade 5

- Death before hospital discharge