Hypotensive resuscitation( also known as Permissive hypotension): It is a recent evolving approach towards trauma patients by limiting or delaying intravenous fluid resuscitation preoperatively in those with uncontrollable hemorrhage (e.g. pt. with penetrating torso injuries), even if there is hypoperfusion.
The traditional practices of giving liberal IV fluid infusions to all major trauma patients with suspected or known major hemorrhage are now being questioned & not recommended anymore in many current studies.
The recent evidences:- aggressive fluid resuscitation before haemostasis leads to additional bleeding through hydraulic acceleration of hemorrhage, dissolution of soft clots , & dilution of clotting factors.
Although, aggressive pre-op IV fluid infusion is still considered appropriate for unconscious individuals with no palpable blood pressure or for those pt. with controllable hemorrhage (e.g. isolated extremity/head injury); the latest recommendations are different in those with uncontrollable hemorrhage.
Studies have shown that decreasing the amount of fluids during the initial resuscitation period (by following a strategy of hypotensive resuscitation) may improve trauma outcomes.
Hypotensive resuscitation(Permissive hypotension)
–a safe strategy for use in the trauma patients,
-results in a significant reduction in blood product transfusions & overall IV fluid administration.
-resuscitating patients with a target, minimum MAP= 50 mm Hg, (& not 65 mm Hg), significantly decreases postoperative coagulopathy & minimizes the risk of early postoperative death.
– by providing O2 delivery with slow, limited infusion, & new Hb-based O2 carriers can help to resolve the current dilemma limiting the preoperative resuscitation for the pt. with risk of uncontrolled hemorrhage.
Hypotensive resuscitation/Permissive hypotension-a hot topic in trauma circles now-a-days
-In the late 20th century, the early management of a truma pt: 2 large-bore IV lines, running wide open.
-The current trend: in ambulances & ER, limited fluid resuscitation, at least, until bleeding controlled – by natural hemostasis, external pressure, angiography or surgery.
*-Rates of bleeding from an arterial injury corresponds to changes in MAP
-early aggressive fluid resuscitation in trauma pt. can increase total amount of bleeding.
-Despite resumption of bleding from the site of injury, delaying fluid resuscitation leads to the best hemodynamic parameters.
Some other terms:
“Deliberate hypotension” (also called “controlled hypotension”, used intraoperatively),
“Delayed resuscitation” (where the hypotensive period is intentionally prolonged until operative intervention) &
“Permissive hypotension” (where restrictive fluid therapy increases systemic pressure without reaching normal BP).