In the Trendelenburg position, the body is laid flat on the back (supine position) with the feet higher than the head by 15-30 degrees, in contrast to the reverse Trendelenburg position, where the body is tilted in the opposite direction. Trendelenburg is a standard position used in abdominal and gynecological surgery. It allows better access to the pelvic organs as gravity pulls the intestines away from the pelvis. It was named after the German surgeon Friedrich Trendelenburg.
In the past, Trendelenburg position was used for patients in hypovolemic shock, with the thought that it would help maintain blood flow to the brain. This is no longer recommended because research shows it to be counterproductive.
- The Trendelenburg position is used to treat a surgical air embolism by placing the right ventricular outflow tract inferior to the right ventricular cavity, causing the air to migrate superiorly into a position within the right ventricle from which air is less likely to embolize. 
- The Trendelenburg position along with the Valsalva maneuver, termed as modified-Valsalva maneuver, is used for the cardioversion of supraventricular tachycardia
- The Trendelenburg position is helpful in surgical reduction of an abdominal hernia.
- The Trendelenburg position is also used when placing a central venous line. The Trendelenburg position uses gravity to assist in the filling and distension of the upper central veins when placing a central line in the internal jugular or subclavian veins. It is also used in the placement of an external jugular peripheral line for the same reason. It plays no role in the placement of a femoral central venous line.
- The Trendelenburg position is also used in respiratory patients to create better perfusion.
- The Trendelenburg position has occasionally been used to produce symptomatic relief from septum posticum cysts of the subarachnoid space in the spinal cord, but does not bring about any long term benefits.
- The Trendelenburg position may be used for drainage images during endoscopic retrograde cholangiopancreatography. 
- People with hypotension (low blood pressure) have historically been placed in the Trendelenburg position in hopes of increasing their cerebral perfusion pressure (the blood pressure to the brain). A 2005 review found the "Literature on the position was scarce, lacked strength, and seemed to be guided by 'expert opinion.'" A 2008 meta-analysis found adverse consequences to the use of the Trendelenburg position and recommended it be avoided. However, the passive leg raising test is a useful clinical guide to fluid resuscitation and can be used for effective autotransfusion.
- The Trendelenburg position used to be the standard first aid position for shock.
- The Trendelenburg position was used for injured scuba divers. Many experienced divers still believe this position is appropriate, but current scuba first aid professionals no longer advocate elevating the feet higher than the head. The Trendelenburg position in this case increases regurgitation and airway problems, causes the brain to swell, increases breathing difficulty, and has not been proven to be of any value. "Supine is fine" is a good, general rule for victims of submersion injuries unless they have fluid in the airway or are breathing, in which case they should be positioned on the side.
- Trendelenburg gait
- Trendelenburg's sign
- Fowler's position
- High Fowlers position
- Recovery position
- Semi-Fowlers position
- Lift chair
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