Table 1 Patient characteristics

Baseline characteristics

Age (years)

46 ± 17.6; range 21–77

Sex, male

12 (60%)

Ethnicity

 Caucasian

19 (95%)

 African

1 (5%)

Weight (kg)

79 ± 12

Height (cm)

176 [170–184]

BMI (kg/m²)

25 ± 3; range 19–29

ASA classification

 ASA I

14 (70%)

 ASA II

6 (30%)

Lifestyle factors

 Current smoking

1 (5%)

 Past smoking

9 (45%)

 Alcohol use

17 (85%)

No medication use

9

MoCA score

27 [26–29]

Surgical characteristics

Type of surgery

 Urological

1 (5%)

 Orthopaedic

17 (85%)

 Surgical

2 (10%)

Spinal technique characteristics

Puncture level

 L1–L2

1 (5%)

 L2–L3

2 (10%)

 L3–L4

13 (65%)

 L4–L5

4 (20%)

CSF aspiration time (minutes)

2 [2, 3]; range 1–4