Permissive Hypotension

Excerpt

Permissive hypotension, commonly known as hypotensive resuscitation, is the method of deliberately allowing the patient's mean arterial pressure (MAP) to remain lower than normal physiological levels. This technique is commonly employed to address acute hemorrhagic volume depletion arising from severe trauma. Hemorrhagic shock is one of the most common causes of mortality in trauma patients. Permissive hypotension serves only as a temporizing measure before hemorrhage control or surgery can be performed. Hemodynamic parameters should be corrected to normal ranges when blood products and improved hemorrhage control measures are available.

Hypotensive resuscitation's role in patients with penetrating trauma was initially investigated by Bickell WH et al, though the concept dates back to World War I. Various studies have described a mortality reduction when blood pressures are adjusted below the normal physiologic range. Postoperative recovery time is also shorter when permissive hypotension is put into practice, as opposed to immediately normalizing an individual's blood pressure.

However, data do not support any specific algorithmic pressure stabilization approaches in patients with different confounding factors, such as age, preexisting health conditions, and injury mechanisms. Given the methods of performing this intervention, the challenge of hypotensive resuscitation lies in how low one should set the limiting threshold.