Central venous catheterization (CVC) is required for the purposes of CVP monitoring, transvenous cardiac pacing, hemodialysis access, cancer patients with difficult venous access,  chemotherapy, sick patients, volume resuscitation and patients undergoing major surgery.
The IJV, subclavian, and femoral veins are the mainly three large venous routes for central line insertion; each has pros, cons, and possible difficulties of its own.

When it comes to central venous catheterization, subclavian vein catheterization (SCV) is the preferred option over internal jugular veins (IJVs) for a number of reasons. These include a lower risk of infection when compared to femoral or internal jugular sites, ease of placement for patients who are immobilized due to severe trauma, less interference during endotracheal intubation, mechanical ventilation during Cardiopulmonary Cerebral Resuscitation (CPCR), and reduced patient discomfort when receiving long-term intravenous treatment. In comparison to internal jugular vein or femoral vein cannulation, it also carries a lower risk of thrombosis. When  hypovolemic shock occurs, this large diameter vein frequently stays patent due to the surrounding support structures. As the SCV is located very close to  structures like  subclavian artery and lungs, SCV cannulation can cause  complications such as subclavian artery puncture causing hematoma, hemothorax and pneumothorax. USG guided approach is superior to landmark guided approach.

The benefit includes an increase success rate, great efficiency and decreased complications.

CVC under direct vision using USG needs a lesser number of attempts, decreases the time required for insertion, and reduces complications like accidental arterial puncture, pnemothorax, and wrong guidewire position . SCV can be cannulated by supraclavicular and infraclavicular approaches.

The supraclavicular approach have advantage over infraclavicular approach such as a well defined insertion landmark, a shorter skin to vein distance, a larger target area, a straighter path to superior vena cava, less proximity to the lung, and fewer complications of pleural and arterial puncture.

The study will be carried out as there is scarcity of literature on comparison of USG guided Supraclavicular  and Infraclavicular approach for Subclavian vein cannulation so the relative efficacy of one over the other is debatable. By shedding light on comparative merits of Supraclavicular and Infraclavicular approach, this investigation will help anaesthetic practitioners in choosing a better treatment plan for the patients.

Therefore this study is to compare Infraclavicular approach to Supraclavicular approach for ease of subclavian vein cannulation under ultrasound guidance.