Absolute contraindications: Patient refuses, clinically in shock, presence of infection at injection site.

Absolute contraindications: patient refuses, clinically in shock, presence of infection at injection site.

Relative contraindications: coagulation disorders, spine disorders, increased intracranial pressure, uncooperative patient.

Absolute contraindications: patient refuses, clinically in shock, presence of infection at injection site, coagulopathy, currently on anticoagulants, increased intracranial pressure, severe aortic stenosis, severe mitral stenosis.

Relative: sepsis, bacteremia, uncooperative patient, presence of neurological deficits, aortic valce stenosis, spine disorders.

Controversial: Presence of infection at injection site, patient is unable to communicate, prolonged surgery, patient has a high risk of major haemorrhage.