This is a prospective observational study conducted in a mixed medical surgical intensive care unit to assess the usefulness of routinely available hemodynamic parameters for predicting fluid responsiveness in adult patients with septic shock. Adult mechanically ventilated patients with septic shock who have a central venous catheter and invasive arterial blood pressure monitoring and are receiving stable low dose noradrenaline will be included when a fluid challenge is clinically indicated as part of standard care. A standardized fluid bolus of 250 ml crystalloid will be administered over ten minutes. Changes in central venous pressure pulse pressure and echocardiographic left ventricular outflow tract velocity time integral will be recorded immediately before and after the fluid challenge. Fluid responsiveness will be defined as a ten percent or greater increase in velocity time integral. The study will evaluate the diagnostic accuracy of combined changes in central venous pressure and pulse pressure for predicting fluid responsiveness using appropriate statistical models accounting for repeated measurements. The findings of this study are expected to help identify a simple practical and cost-effective approach to guide fluid therapy in intensive care units especially in resource limited settings.