Table 1

Baseline patient characteristics and surgical characteristics

TMH group
(n=20)
TN group
(n=20)
Patient characteristics
Gender (male:female)11:912:8
Age (years)63.7 (32–81)65.4 (31–81)
Age >65 (years)9 (45.0)11 (55.0)
Weight (kg)83.7 (56.8–110.6)81.2 (67.9–94.5)
BMI (kg/m2)33.6 (20.7–46.5)32.8 (26.8–38.8)
ASA status
 15 (25.0)2 (10.0)
 26 (30.0)4 (20.0)
 37 (35.0)10 (50.0)
 42 (10.0)4 (20.0)
Diabetes4 (22.2)5 (25.0)
COPD5 (27.8)0 (0.0)
Malignancy11 (61.1)7 (35.0)
Other comorbidities11 (61.1)16 (80.0)
Surgical characteristics
Duration of surgery (min)219.0 (123.8–303.8)144.0 (107.8–218.2)
Left baseline oximetry (%)68.7 (63.9–72.2)63.4 (57.3–69.6)
Right baseline oximetry (%)67.9 (64.6–70.3)64.0 (59.4–69.0)
Pulse oximetry (%)98.5 (98.1–99.0)98.5 (97.9–99.0)
LOS (days)5 (2.0–12.0)5 (1.8–11.5)
Type of surgery
 Colorectal2 (10.0)1 (5.0)
 Endocrine2 (10.0)2 (10.0)
 Ear, nose and throat0 (0.0)1 (5.0)
 Hepatobiliary6 (30.0)9 (45.0)
 Spinal surgery1 (5.0)1 (5.0)
 Orthopaedic2 (10.0)1 (5.0)
 Thoracic5 (25.0)1 (5.0)
 Urology2 (10.0)3 (15.0)
 Vascular0 (0.0)1 (5.0)
  • Data reported as number (%) or median (IQR), except for age, which is reported as mean (range).

  • Other comorbidities include any of the following, ischaemic heart disease, atrial fibrillation, hypertension, history of cerebral vascular disease and chronic kidney impairment.

  • Spinal surgery includes non-intracranial procedures.

  • Thoracic surgery includes procedures not requiring one lung ventilation, for example, mediastinoscopy with nodal dissection.

  • ASA, American Society of Anesthesiologists; BMI, body mass index; COPD, chronic obstructive pulmonary disease; LOS, length of hospital stay.