Hemorrhagic shock is a pathologic state in which intravascular volume and oxygen delivery are impaired. During circulatory failure associated with hypovolemia and low cardiac output, redistribution of blood flow caused by increased vasoconstriction results in decreased perfusion of the skin.

Skin temperature and capillary refill time has been advocated as a measure of peripheral perfusion.

Perfusion index (PI) is a non-invasive numerical value of peripheral perfusion obtained from pulse oximetry, it is an indicator of the pulse strength at the sensor site. The PI's values range from 0.2% for very weak pulse to 20% for extremely strong pulse according to patient's physiological conditions and monitoring sites.

Large increases in lactate (i.e. > 5 mmol/L) usually only occur due to hypoperfusion or muscle activity such as exercise or seizures.

This study will investigate the role of nitroglycerine patch in improving the peripheral perfusion in poly traumatized patient with hemorrhagic shock for the first time.

Inclusion Criteria:

• Age: 20-60 years old. With the patient fully conscious or slightly drowsy.
• Blood pressure: Systolic blood pressure below 90mmhg ,mean blood pressure below70mmhg or decrease of systolic blood pressure 40mmhg below normal value.
• Metabolic acidosis: PH less than 7.35 due to hypoperfusion.
• Capillary refill time > 4 seconds.
• Normal body core temperature.

Exclusion Criteria:

• Age: below 20 and above 60 years old.
• Head trauma with Glasco coma score below 14 due to increased intracranial pressure (stroke, subarachnoid hemorrhage or brain trauma injury).
• Severe hypotension not responding to fluid therapy.
• Patient with bilateral ischemic arm injury.
• Patient with hepatic cell failure
• Patients admitted to the emergency trauma department after 6 hours of the trauma event.
• Preexisting conditions as severe cardiovascular disease, uncontrolled hemorrhage, failure of central venous catheterization, dialytic procedure anticipated during the study period.