Abstract
Introduction
Cases of septicemia with characteristic features of septic shock showing intravascular volume depletion, inadequate and non-uniform distribution of regional blood flow, reduced peripheral resistance along with aggravating hypotension are quite common in the intensive care units all around the world. Dopamine has been considered as the first-line vasoactive agent, in the management of septic shock. However there are concerns regarding tachyarrhythmia, elevated myocardial oxygen requirements, associated gut ischemia, and undesirable endocrine effects with the use of dopamine. The basic aim of this study was to evaluate the efficacy of phenylephrine in comparison to nor-epinephrine among patients presenting with septic shock in the intensive care unit of a tertiary care hospital in Pakistan.

Methods
This study was conducted at the Intensive care Unit of Holy Family Hospital, Rawalpindi Medical College, Rawalpindi, Pakistan over a period of 1 year from Jan 2012 till December 2012. A total of 42 participants presenting with septic shock, admitted in the intensive care unit regardless of the causation were recruited in the study. Patients with clinically defined septic shock having persistent hypotension, evidence of one or more end organ dysfunction, infection along with two or more additional sepsis clinical features were recruited. The participants were then randomly divided in to two groups depending upon the drug given. Group A included participants who received Phenylephrine while group B received Noradrenaline. The target of therapy was to achieve stable hemodynamics in terms of SBP > 90 mm Hg and/or MAP > 75 mm Hg. Serial IV fluid challenge so as to maintain CVP in the normal range along with dopamine infusion at a rate of 25µg/kg/min were continued throughout the study duration. The response was considered significant if the subjects achieved and maintained the pre-defined targets of therapy for a period of continuous 4-6 hours, in the specified dose range.

Results
There was no considerable difference in amount of fluid infusion given during the study phase in both groups. Maximum infusion requirement of Phenylephrine and Noradrenaline were 4.37 ± 1.87µg/kg/min and 3.98 ± 1.31 µg/kg/min, respectively. There was significant increase in post-treatment levels of Systolic blood pressures (75.41±3.22 vs. 103.24±12.32,P<0.05 in group A and 73.89±5.60 vs112.45±3.64,P<0.05 in group B) , mean arterial pressures (48.35±4.28 vs. 77.38±3.17, P<0.05 in group A and 47.15±5.02 vs. 75.45±8.24,P<0.05 in group B) and the urine output (0.22±0.02 vs. 0.51±0.04, P<0.05 in group A and 0.19±0.06 vs. 0.55±0.07,P<0.05 in group B) among both the groups.
The drop in heart rate was not significant in group B, making this study significant( post treatment heart rate in group A 114.23±4.86 vs. 145±8.65 in group B) in terms of conclusion that Phenylephrine is much significant in controlling the tachycardia existing amon

Key words: Septic Shock, Phenylephrine, Noradrenaline