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Trendelenburg position

Trendelenburg position is a biology topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Trendelenburg position rather than just read about it. In short: In the Trendelenburg position (), the body is lain supine, or flat on the back on a 15–30 degree incline with the feet elevated above the head. The reverse Trendelenburg position, similarly, places the body supine on an incline but with the head now being elevated.

Trendelenburg position — main illustration
Trendelenburg position — illustration

Key takeaways

  • Trendelenburg position belongs to biology; place it in that map before memorising details.
  • Learn the definition first, then one example that makes the definition concrete.
  • Connect Trendelenburg position to a quantity you can measure, compute or draw — that is where exam questions come from.
  • Reproduce the core statement of Trendelenburg position from memory before moving on to harder problems.

Reference excerpt

In the Trendelenburg position (), the body is lain supine, or flat on the back on a 15–30 degree incline with the feet elevated above the head. The reverse Trendelenburg position, similarly, places the body supine on an incline but with the head now being elevated. The Trendelenburg position is used in surgery, especially of the abdomen and genitourinary system. It allows better access to the pelvic organs as gravity pulls the intra-abdominal organs away from the pelvis. Evidence does not support its use in hypovolaemic shock, with concerns for negative effects on the lungs and brain. The position was named for the German surgeon Friedrich Trendelenburg (1844–1924).

Typical use

The Trendelenburg position can be used to treat a venous 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 embolise. Most recently, the reverse Trendelenburg position has been used in minimally invasive glaucoma surgery, also known as MIGS. This position is commonly used for a superior sitting surgeon that uses a combination of downward patient tilt, of approximately 30 to 35 degrees, microscope tilt towards themselves at the same angle and an intraoperative goniolens or prisms that allows them to visualise the inferior trabecular meshwork. Some joysticking of the globe may be required with an appropriate goniolens to bring the meshwork into view.

The Trendelenburg position along with the Valsalva maneuver, termed as modified-Valsalva maneuver, can also be 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 catheter in the internal jugular or subclavian vein. The Trendelenburg position uses gravity to assist in the filling and distension of the upper central veins, as well as the external jugular vein. It plays no role in the placement of a femoral central venous catheter. The Trendelenburg position can also be 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. The Trendelenburg position is reasonable in those with a cord prolapse who are unable to achieve a knee-to-chest position. It is a temporary measure until a cesarean section can be performed. If a patient in a Fowler's position or semi-Fowlers position has sunk too far down into the bed, they may temporarily be put in a Trendelenburg position while staff reposition them. This does not have a direct therapeutic action but rather provides a mechanical advantage

Controversial use

People with hypotension (low blood pressure) have historically been placed in the Trendelenburg position in hopes of increasing blood flow 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 can also be used in the treatment of scuba divers with decompression sickness or arterial gas embolism. Many experienced divers still believe this position is appropriate, but 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 in the recovery position.

See also Fowler's position High Fowler's position Recovery position Semi-Fowler's position Trendelenburg gait Trendelenburg's sign

References

External links

Illustration of position in comparison to other positions Archived 2018-01-18 at the Wayback Machine Human Kinetics' Victim Positioning According to The Canadian Journal of Anesthesia

Illustrations

Trendelenburg position: Medical mannequin placed in the Trendelenburg position
Medical mannequin placed in the Trendelenburg position
Trendelenburg position: Trendelenburg position
Trendelenburg position
Trendelenburg position: Reverse Trendelenburg
Reverse Trendelenburg
Trendelenburg position: A historic depiction of the Trendelenburg position
A historic depiction of the Trendelenburg position

Worked examples

Example 1 — a first encounter with Trendelenburg position

Start with the simplest possible case. Write down what Trendelenburg position claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In biology, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Trendelenburg position before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Trendelenburg position ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Trendelenburg position

In research
Trendelenburg position appears in biology research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry
Engineering practice reuses Trendelenburg position in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom
Trendelenburg position is common in secondary-school and first-year university syllabi. It links to neighbouring topics Gynaecology, Human positions, Surgery, so understanding it makes those chapters shorter.
In everyday life
Look for Trendelenburg position outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Trendelenburg position in 20 minutes

  1. Read the reference excerpt below once, without taking notes.
  2. Close the page and write down what Trendelenburg position means in your own words.
  3. Compare your version with the excerpt and mark what you missed.
  4. Work through the three examples above with pen and paper.
  5. Explain Trendelenburg position out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Trendelenburg position in simple terms?

In the Trendelenburg position (), the body is lain supine, or flat on the back on a 15–30 degree incline with the feet elevated above the head. The reverse Trendelenburg position, similarly, places the body supine on an incline but with the head now being elevated.

Why does Trendelenburg position matter?

Because it connects several biology ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Trendelenburg position?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Trendelenburg position.

Tags

  • Gynaecology
  • Human positions
  • Surgery

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