Clinical trials

The goal of this observational study is to compare spinal anaesthesia success in adults with and without previous lower back surgery. The main question it aims to answer is: \- Does previous lower back surgery affect the success of spinal anaesthesia on the first needle insertion? Participants will receive spinal anaesthesia as part of their usual medical care. Researchers will record needle attempts, procedure time, and anaesthesia effectiveness. Participation will not involve additional procedures or changes to routine care.