| Low Tidal Volume (n = 614) | Conventional Tidal Volume (n = 592) |
---|---|---|
Age, years | 65.0 (54.0 – 72.0) | 64.0 (55.0 – 72.0) |
Male gender | 366 (59.6) | 346 (58.4) |
Body weight, kg | ||
  Actual | 80.0 (68.0 – 95.0) | 80.5 (70.5 – 94.0) |
  Predicted | 63.3 (56.0 – 70.6) | 64.2 (55.1 – 70.6) |
Body mass index, kg/m2 | 27.9 (24.4 – 32.5) | 28.1 (25.1 – 32.0) |
ARISCAT risk score | 26.0 (19.0 – 37.0) | 26.0 (19.0 – 35.8) |
  Low | 193 (34.8) | 196 (37.8) |
  Moderate | 324 (58.5) | 282 (54.4) |
  High | 37 (6.7) | 40 (7.7) |
Preoperative SpO2, % | 97.0 (96.0 – 98.0) | 97.0 (96.0 – 98.0) |
Preoperative HCO3, mmol/L | 26.0 (24.0 – 27.0) | 26.0 (24.0 – 28.0) |
Preoperative haemoglobin, g/dL | 138.0 (127.0 – 149.0) | 138.0 (124.0 – 149.0) |
Preoperative creatinine, mg/dL | 0.88 (0.74 – 1.06) | 0.87 (0.75 – 1.06) |
Co-morbidities | ||
  Diabetes mellitus | 119 (19.4) | 126 (21.3) |
  Hypertension | 301 (49.1) | 327 (55.3) |
  Coronary artery disease | 93 (15.2) | 100 (16.9) |
  Chronic renal disease | 56 (9.1) | 67 (11.3) |
  Chronic liver disease | 48 (7.8) | 52 (8.8) |
  Current smoker | 100 (16.3) | 109 (18.4) |
  COPD | 62 (10.1) | 65 (11.0) |
  Asthma | 66 (10.7) | 68 (11.5) |
  Interstitial lung disease | 8 (1.3) | 2 (0.3) |
  Bronchiectasis | 1 (0.2) | 1 (0.2) |
  Obstructive sleep apnoea | 59 (9.6) | 63 (10.6) |
  Obesitya | 225 (37.8) | 207 (36.8) |
  Recent LRTI | 8 (1.3) | 8 (1.4) |
Type of Surgery | ||
  Abdominal | 348 (56.7) | 333 (56.3) |
  Laparoscopic | 158 / 348 (45.4) | 170 / 333 (51.1) |
  General | 6 (1.0) | 2 (0.3) |
  Ear, nose and throat | 17 (2.8) | 13 (2.2) |
  Orthopaedic | 43 (7.0) | 46 (7.8) |
  Plastic | 31 (5.0) | 36 (6.1) |
  Spine | 125 (20.4) | 120 (20.3) |
  Vascular | 29 (4.7) | 28 (4.7) |
  Others | 15 (2.4) | 13 (2.2) |
Duration of surgery, minutes | 189.5 (135.0 – 267.5) | 185.0 (140.5 – 249.5) |