From: Incidence and factors associated with failed spinal anaesthesia among patients undergoing surgery: a multi- center prospective observational study
Variables
Category
Frequency (n)
Percentage (%)
CSF flow
Clear
467
88%
Bloody
65
12%
Barbotage
Yes
313
59%
No
219
41%
Number of spinal attempt
1–2 times
463
87%
3–5 times
69
13%