The accuracy of pulse pressure variation also can be compromised in right heart failure, decreased lung or chest wall compliance, and high respiratory rates.Similar to examining pulse pressure variation, measuring respiratory variation in inferior vena cava diameter as a measure of volume responsiveness has only been validated in patients without spontaneous breaths or arrhythmias.Measuring the effect of passive leg raises on cardiac contractility by echo appears to be the most accurate measurement of volume responsiveness, although it is also subject to limitations.History and physical can often make the diagnosis of hypovolemic shock. For patients with hemorrhagic shock, a history of trauma or recent surgery is present. For hypovolemic shock due to fluid losses, history and physical should attempt to identify possible GI, renal, skin, or third-spacing as a cause of extracellular fluid loss.Although relatively nonsensitive and nonspecific, physical exam can be helpful in determining the presence of hypovolemic shock. Physical findings suggestive of volume depletion include dry mucous membranes, decreased skin turgor, and low jugular venous distention. Tachycardia and hypotension can be seen along with decreased urinary output. Differential diagnosis
While hemorrhage is the most common cause of shock in the trauma patient, other causes of shock are to remain on the differential. Obstructive shock can occur in the setting of tension pneumothorax and cardiac tamponade. These etiologies should be uncovered in the primary survey. In the setting of head or neck trauma, an inadequate sympathetic response, or neurogenic shock, is a type of distributive shock that is caused by a decrease in peripheral vascular resistance.
Patients in shock can appear cold, clammy, and cyanotic.Hypothermia increases the mortality rate of patients with hypovolemic shock. It is advised to keep the patient warm for the sake of maintaining the temperatures of all kinds of fluids inside the patient. Monitoring parameters
Oxygen saturation by pulse oximetry (SpO2). Respiratory rate. Pulse rate. Arterial blood pressure. Pulse pressure. Central venous pressure. Urine output. Base deficit and/or lactic acid. Temperature. Mental state. Changes in the electrocardiogram. Prognosis
If the vital organs are deprived of perfusion for more than just a short time, the prognosis is generally not good. Shock is still a medical emergency characterized by a high mortality rate. Early identification of patients who are likely to succumb to their illness is of utmost importance. Epidemiology
Blood loss
Trauma remains a leading cause of death worldwide with approximately half of these attributed to hemorrhage. In the United States in 2001, trauma was the third leading cause of death overall, and the leading cause of death in those aged 1 to 44 years. While trauma spans all demographics, it disproportionately affects the young with 40% of injuries occurring in ages 20 to 39 years by one countrys account. Of this 40%, the greatest incidence was in the 20 to 24-year-old range.The preponderance of hemorrhagic shock cases resulting from trauma is high. During one year, one trauma center reported 62.2% of massive transfusions occur in the setting of trauma.