Observational Study About the Use of Perfusion Index to Use Vasopressor in Sepsis

Inclusion Criteria: \- All ICU patients with clinically suspected sepsis and septic shock ( signs include fever hypotension oliguria and confusion combined with culture results showing infection .Septic shock is a subset of sepsis involves persistent hypotension (mean arterial pressure ≥ 65 mm Hg, and a serum lactate level \> 18 mg/dL \[2 mmol/L)not responding to fluid resuscitation ) . Exclusion Criteria: * Pregnant females * Patients on vasopressor or positive inotropic drugs * Patients with hypothermia (defined as central temperature \<35°C). * Patient with impairment of upper extremity circulation,(such as those who underwent radial artery harvesting for coronary artery bypass grafting or had suspected occlusion of the radial artery prior to surgery,) * Patients had undergone an operation that involved the large arteries of the aortic arch. * Patients with atherosclerosis .