Fixation of fractured neck of femur is a common Orthopedic surgery. Anaesthesia can be
challenging in some cases like in haemodynamical unstable patients.

The investigators have evidence of minimum effective local anaesthetic dose (MLAD) in hip
replacement surgery but MLAD to achieve surgical anaesthesia for operative fixation of FNF is
still unknown.

A step-up/step-down methodology was used successfully in regional anaesthesia and also in
other areas of anaesthesia.

In pregnant ladies in whom spinal anaesthesia is performed on the side, significant
correlation exist between the vertebral length measured from cervical 7 to the iliac creast
and MLAD.

The investigators aim it was to determine the MLAD of hyperbaric 0.5% bupivacaine required
for Continuous spinal anaesthesia for the operative fixation of FNF.