Table 5.
Patient outcomes
| Variable | All patients | Low risk of PPCs | Increased risk of PPCs | Relative Risk (95% CI) | P |
| Postoperative pulmonary complications | |||||
| Total PPCsa | 10.4 (1004/9697) | 7.0 (467/6675) | 19.2 (505/2632) | 3.16 (2.76 to 3.61) | <0.001 |
| Unplanned supplemental O2b | 8.5 (826/9697) | 5.8 (390/6675) | 15.5 (408/2632) | 2.96 (2.55 to 3.42) | <0.001 |
| Respiratory failure | 1.6 (156/9697) | 0.9 (60/6675) | 3.4 (90/2632) | 3.90 (2.81 to 5.43) | <0.001 |
| Invasive MV | 1.1 (107/9697) | 0.6 (41/6675) | 2.3 (61/2632) | 3.84 (2.58 to 5.72) | <0.001 |
| ARDS | 0.1 (9/9697) | 0.0 (1/6675) | 0.3 (8/2632) | 20.35 (2.54 to 162.76) | <0.001 |
| Pneumonia | 0.4 (40/9697) | 0.1 (10/6675) | 1.1 (28/2632) | 7.17 (3.48 to 14.77) | <0.001 |
| Pneumothorax | 0.1 (13/9697) | 0.1 (8/6675) | 0.2 (4/2632) | 1.27 (0.38 to 4.23) | 0.697 |
| Postoperative outcome | |||||
| Length of hospital stay | 1.0 [0.0 to 4.0] | 1.0 [0.0 to 3.0] | 4.0 [1.0 to 7.0] | - | <0.001 |
| In-hospital mortality | 0.6 (56/8973) | 0.2 (13/6163) | 1.7 (41/2445) | 8.07 (4.32 to 15.08) | <0.001 |
| Hospital-free daysc | 26.0 [23.0 to 27.0] | 26.0 [24.0 to 27.0] | 23.0 [21.0 to 26.0] | - | <0.001 |
Low versus increased risk of PPCs, according to the Assess Respiratory Risk in Surgical Patients in Catalonia (ARISCAT) risk score (<26 versus ≥26, respectively).
Data are presented as proportion, % (n/N) or median [LQ − UQ].
Comparison of differences within a subgroup is performed by using the t-test for continuous variables and χ2 for categorical variables.
ARDS, acute respiratory distress syndrome; CI, confidence interval; LOS, length of hospital stay; LQ, lower quartile; MV, mechanical ventilation; N, number in group or subgroup; n, number with characteristic; NIV, noninvasive ventilation by mask or helmet; PPCs, Postoperative pulmonary complications; PPCs: on day 1 to 5 were scored YES as soon as the event occurred on either ward or intensive care unit; UQ, upper quartile.
aTotal PPCs: one patient could present with multiple PPCs but was scored only once (YES or NO principle).
bunplanned supplementary O2: supplemental oxygen administered due to PaO2 <8 kPa or SpO2 <90% in room air, excluding oxygen supplementation given as standard care (e.g. directly after arrival in the Post Anaesthesia Care Unit.
cHospital-free days when discharged and alive at day 28.