Table 1 Characteristics of study patients

Age in years

56 (42–69)

Male (%)

150 (55)

Height in cm

170 (162–176)

Actual weight in kg

75 (67–89)

Ideal body weight in kg

52.9 (IQR 48.6-58.6)

Body mass index in kg per m²

25.9 (IQR 24.4- 30.8)

ASA status (%)

I

48 (17.6)

II

107 (39.4)

III

81 (29.8)

IV

29 (10.6)

V

1 (0.4)

Unknown

6 (2.2)

Emergency

22 (8.1)

Respiratory disease (%)

73 (26.8)

Cardiac disease (%)

66 (24.3)

Type of surgery (%)

General

86 (31.6)

Cardiac

21 (7.7)

Thoracic

6 (2.2)

Maxillofacial/Dental

9 (3.3)

Gynaecology

2 (0.7)

Obstetrics

4 (1.4)

Opthalmology

4 (1.5)

Orthopaedics/Spinal

55 (20.2)

Neurosurgery

26 (9.6)

Urology

20 (7.4)

Vascular

15 (5.5)

Plastics/Burns

16 (6.1)

Other

8 (3)

Hospital type (%)

Secondary

48 (17.6)

Tertiary

224 (82.4)

Type of anaesthesia (%)

General anesthesia

262 (96.3)

Regional anaesthesia

10 (3.7)

Expected duration of surgery (%)

<30 mins

12 (4.4)

30-60 mins

56 (20.6)

1-2 hrs

82 (30.1)

2-4 hrs

79 (29.0)

>4 hrs

30 (11.0)

Unknown

13 (4.9)