After getting approval from institutional ethical committee, written informed consent will be obtained from all those patients and/or attendants  who will fulfill the inclusion criteria. Exclusion criteria are age <18 or >90, Peripheral vascular diseases  upper limb surgeries planned radial artery harvesting recent trans radial intervention, recent acute myocardial infarction or percutaneous coronary intervention (PCI), active malignancy, autoimmune disease, bleeding disorders, recent stroke, functional impairment of the non-dominant arm, pregnancy, severe anemia or thrombocytopenia. Radial artery cannulation will be done in the non-dominant hand of the subject using catheter-over-needle technique - 20-gauge, 1.75-in. (4.45-cm) polyurethane catheter over 22-gauge introducer needle or catheter-over-wire technique (modified Seldinger) - 20-gauge peripheral artery catheter kit with integrated wire and catheter. Perfusion index will be measured using hand held pulse oximeter placed on the index finger 1 minute before the intervention (baseline) and  at 1, 10 and 30 minutes after the intervention. The PI ratio will be calculated as the ratio between the PI at 10 minutes after intervention and the baseline PI. Comparison between the values of PI  before and after the intervention will be done and statistically assessed. A comparison between the cannulated and non cannulated limb will also be performed in every patient.