Table 1.
Subject and procedure characteristics. Data represent median (Q1–Q3) or number of subjects (% of column). ∗P-values are calculated from Kruskal–Wallis test (for continuous variables) or Fisher's exact test (extended). aThese differences between randomised subjects are considered owing to chance and post hoc comparisons not shown.
| Variables | Control (n=13) | PEEPmaxCrs (n=16) | PEEPPtp_ee (n=8) | P-value∗ |
|---|---|---|---|---|
| Demographics | ||||
| Age (yr) | 69 (61–73) | 60 (47–75) | 55 (51–67) | 0.501 |
| Gender (male) | 7 (54) | 8 (50) | 4 (50) | 1.000 |
| Body mass index (kg m−2) | 26.4 (22.8–29.6) | 23.4 (20.8–25.4) | 24.7 (24.1–27.7) | 0.187 |
| Comorbidities | ||||
| Hypertension | 10 (77) | 2 (12) | 2 (25) | 0.002a |
| Coronary artery disease | 0 (0) | 2 (12) | 0 (0) | 0.496 |
| Heart failure | 1 (8) | 1 (6) | 0 (0) | 1.000 |
| Neurological disease | 1 (8) | 0 (0) | 1 (12) | 0.316 |
| Chronic obstructive pulmonary disease | 0 (0) | 1 (6) | 1 (12) | 0.688 |
| Asthma | 1 (8) | 2 (12) | 2 (25) | 0.695 |
| Obstructive sleep apnoea | 3 (23) | 1 (6) | 1 (12) | 0.495 |
| Smoking | 0.534 | |||
| Never | 9 (69) | 8 (50) | 7 (88) | |
| Former | 2 (15) | 5 (31) | 1 (12) | |
| Current <2 packs day−1 | 2 (15) | 3 (19) | 0 (0) | |
| Renal disease | 0 (0) | 2 (12) | 0 (0) | 0.496 |
| Liver disease | 1 (8) | 1 (6) | 1 (12) | 1.000 |
| Alcohol use (previous yr) | 0.374 | |||
| Never | 5 (38) | 5 (31) | 6 (75) | |
| Occasional | 5 (38) | 9 (56) | 2 (25) | |
| Moderate | 2 (15) | 2 (12) | 0 (0) | |
| Heavy | 1 (8) | 0 (0) | 0 (0) | |
| Cancer | 8 (62) | 11 (69) | 4 (50) | 0.629 |
| Gastro-oesophageal reflux disease | 7 (54) | 5 (31) | 3 (38) | 0.473 |
| Diabetes mellitus | 0 (0) | 1 (6) | 1 (12) | 0.688 |
| Total ARISCAT score | 41 (41–41) | 41 (35–49) | 41 (38–41) | 0.900 |
| Surgical procedure | ||||
| Surgical service | 0.717 | |||
| General surgery | 8 (62) | 12 (75) | 7 (88) | |
| Gynaecology | 2 (15) | 2 (12) | 1 (12) | |
| Urology | 3 (23) | 1 (6) | 0 (0) | |
| Other | 0 (0) | 1 (6) | 0 (0) | |
| Surgical approach | 0.416 | |||
| Supra-umbilical | 5 (38) | 9 (56) | 6 (75) | |
| Infra-umbilical | 6 (46) | 3 (19) | 1 (12) | |
| Laparoscopic | 2 (15) | 4 (25) | 1 (12) | |
| Surgery duration (min) | 185 [144–236] | 212 [179–340] | 274 [200–343] | 0.156 |
| Anaesthesia duration (min) | 243 [173–286] | 277 [217–397] | 322 [205–360] | 0.279 |