Table 1

Patient study variables in the positive and negative Air-Test results groups

Positive Air-Test result (n=62)Negative Air-Test result (n=108)p Value
Demographic data
 Age, years65 (11)56 (17)<0.001
 Women, n (%)33 (6)56 (9)0.01
 Height, cm164 (9)166 (9)0.06
 Body weight, kg84 (21)73 (15)<0.001
 ARISCAT score26 (14)16 (15)0.01
 Preoperative SpO2, %98 (1)98 (2)0.12
 Lower abdominal surgery24 (38)34 (31)0.20
 Upper abdominal surgery9 (14)13 (12)0.11
 Peripheral surgery29 (46)60 (55)0.06
 Duration of surgery, min137 (62)119 (63)0.27
Intraoperative ventilatory management
 Tidal volume, mL470 (52)460 (88)0.33
 Respiratory rate, breaths/min12 (1)12 (2)1.00
 PEEP, cmH2O6 (1)6 (2)1.00
 FiO20.6 (0.2)0.7 (0.3)0.88
SpO2 and arterial blood gases in PACU at the end of the Air-Test
 Postoperative SpO2, %91 (3)99 (1)0.01
 PaO2, mm Hg66 (10)87 (12)0.01
 PaCO2, mm Hg41 (6)42 (6)0.29
 pH7.37 (0.04)7.38 (0.03)0.06
 MAP, mm Hg79 (12)85 (15)0.07
 Lactate, mmol/L1.1 (0.4)1.0 (0.7)0.32
 Hb, g/dL12.6 (1.7)12.9 (1.1)0.09
 Temperature, °C36.4 (1.9)36.1 (2.1)0.41
 VAS1 (1)1 (1)1.00
  • Data are described as the 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.