Material and Method: This prospective study was approved by our hospital’s ethics committee and was conducted at medical trust hospital. The subjects included 90 patients aged older than 18 years (ASA physical status I–II) scheduled to undergo lower abdominal and lower limb surgeries under spinal anaesthesia. The patients were divided into 2 main group (45 each), hypertensive and normotensive. These groups were further subdivided into 3 subgroup, i.e. P-3 (phenylephrine 3mg), P-1.5 (phenylephrine 1.5mg), C (control). All medication with phenylephrine irrespective of the dose to be administered was made up to a volume of 2ml with 0.9% saline and administered to the patient. Standard monitoring included continuous electrocardiography and pulse oximetry. The percentage changes in MBP and HR was calculated from the difference between the baseline and the lowest recorded MBP and HR, respectively. No sedative medications were given during the procedure.

Results: The six groups were similar in age, weight, height and sex distribution as shown in above table (p>0.05). Episode of hypotension requiring treatment with ephadrin were higher in control (hypertensive and normotensive) group compared to P-3 (hypertensive and normotensive) group (p<0.001) and P-1.5 (hypertensive and normotensive) group (p<0.001).

Conclusion: Pre-emptive injection of intramuscular 1.5 mg of phenylephrine along with moderate fluid loading is a safe and effective method for reducing the incidence of hypotension associated with hyperbaric bupivacaine spinal anesthesia during lower limb and lower abdominal surgery, provided level of block is limited to lower thoracic segments.