Aim of this study is to compare effectiveness of prophylactic norepinephrine infusion and phenylephrine infusion after preloading with crystalloid in preventing hypotension.The primary objective of this study is  to compare the effect of prophylactic norepinephrine infusion and phenylephrine infusion after preloading with crystalloid in preventing hypotension in geriatric patients undergoing proximal femoral nailing surgeries under spinal anaesthesia. Secondary objectives are to assess the incidence of adverse events between the two groups. Total number of 60 patients between the age group of 65-80years, belonging to ASA physical status ii/iii, posted for proximal femoral  nailing surgeries under spinal anaesthesia will be recruited and randomly assigned into two equal groups using computer generated random list. All patients will be preloaded with crystalloids 10ml/kg. After preloading the patients with crystalloids 10ml/kg, subarachnoid block will be achieved with intrathecal 0.5% bupivacaine heavy 2.5ml combined with 25 mics fentanyl. Immediately following subarachnoid block, patients in Group A (n-30) will  receive inj.phenylephrine infusion at rate of  0.5mcg/kg/min and patients in Group B (n-30) will receive  inj.norepinephrine infusion at rate of 0.05 mcg/kg/min. Haemodynamic parameters including mean arterial pressure (MAP) and heart rate (HR) will be assessed. Adverse events such as bradycardia, nausea and vomiting  will  also be recorded. Data will be analysed with chi- square test and student-t test.