Table 2.
Study variables of patients in the positive and negative Air-Test results groups also assessed with a reference standard CT scan
| Positive Air-Test result (n=30) | Negative Air-Test result (n=29) | p Value | |
| Demographic data | |||
| Age, years | 62 (13) | 53 (15) | 0.045 |
| Women, n (%) | 12 (40) | 11 (37) | 0.57 |
| Height, cm | 165 (10) | 163 (12) | 0.32 |
| Body weight, kg | 88 (29) | 75 (17) | <0.001 |
| ARISCAT score | 28 (14) | 14 (15) | <0.001 |
| Preoperative SpO2, % | 98 (2) | 98 (2) | 0.28 |
| Lower abdominal surgery | 39 (10) | 29 (5) | 0.20 |
| Upper abdominal surgery | 6 (3) | 4 (3) | 0.11 |
| Peripheral surgery, % | 55 (11) | 67 (7) | 0.06 |
| Duration of surgery, min | 137 (62) | 119 (63) | 0.27 |
| Intraoperative ventilatory management | |||
| Tidal volume, mL | 472 (50) | 466 (92) | 0.56 |
| Respiratory rate, breaths/min | 12 (1) | 12 (2) | 1.00 |
| PEEP, cmH2O | 6 (1) | 6 (2) | 1.00 |
| FiO2 | 0.7 (0.2) | 0.7 (0.3) | 0.90 |
| SpO2 and arterial blood gases at PACU at the end of the Air-Test | |||
| Postoperative SpO2, % | 92 (3) | 99 (1) | 0.01 |
| PaO2, mm Hg | 78 (21) | 90 (10) | <0.001 |
| PaCO2, mm Hg | 40 (6) | 42 (6) | 0.34 |
| pH | 7.37 (0.04) | 7.38 (0.03) | 0.09 |
| MAP, mm Hg | 81 (12) | 76 (15) | 0.72 |
| Lactate, mmol/L | 1.1 (0.4) | 1.0 (0.6) | 0.52 |
| Hb, g/dL | 12.5 (1.2) | 12.3 (1.6) | 0.41 |
| Temperature, °C | 36.2 (1.9) | 36.2 (2.3) | 0.68 |
| VAS | 1 (1) | 1 (1) | 1.00 |
Data are described as mean (SD) or number/total number (%). The ARISCAT score was used to predict postoperative pulmonary complications.22
ARISCAT, Assess Respiratory Risk in Surgical Patients in Catalonia; FiO2, inspiratory oxygen fraction; Hb, haemoglobin; MAP, mean arterial pressure; PaCO2, carbon dioxide partial pressure; PACU, postanaesthesia care unit; PaO2, arterial oxygen partial pressure; PEEP, positive end-expiratory pressure; pH, acid–base status; SpO2, pulse oximetry haemoglobin saturation; VAS, visual analogue scale.