Monday, March 13, 2017

1873: The Trendelenburg position is born

Figure 1 --FredrichTrendelenburg (1844-1924) (3)
Probably just about every person in the medical profession is familiar with the trendelenburg position.  It's where you set the patient flat on his back (prone position) and lower the head of the bed so that his hips are higher than the head (see figure 2).

This is done for therapeutic reasons.  Respiratory therapists do it to aid in the drainage of secretions during chest physiotherapy.  Chest physiotherapy is where the therapist cups his hands and bangs on the patients chest to a rapid rhythm. Vibrations supposedly help knock sections from the lungs.

By placing the patient in trendelenburg, this allows the now loose secretions to flow to the upper airway, where they can be coughed up or suctioned out.  Patients who require such therapy are any patients with thick, tenacious secretions, such as bronchiectasis or cystic fibrosis.  Sometimes it's done for COPD patients too, and maybe even some asthmatic patients.

Another use for trendelenburg is to help drain blood to the brain to increase blood pressure.  It seems that one of the first reactions when it's determined a person's blood pressure is critically low is to have the patient lie back and set the bed in trendelenburg.  Yet one might wonder: does this really work to lower blood pressure?

Figure 2 --Trendelenburg position for surgery (2)
The Trendelenburg position was first used in the mid 19th century by German physician and surgeon Fredrich Trendelenburg, according to AMargo A. Halm in her 2012 article in American Journal of Critical Care, "Trendelenburg Position: 'Put to Bed' or Angled Toward Use in Your Unit."  (1, page 449)

Halm explains that Trendelenburg used the "technique known in the Middle Ages as the "head-down position."  In his surgical text of 1873, Trendelenburg recognized that raising the patient's hips caused the bulk of abdominal viscera to slide toward the diaphragm, providing a less cluttered operative field for lower abdominal and pelvic procedures." (1, page 449)

It wasn't until the early 20th century that the position was used by physiologist Walter Cannot to "displace blood from the lower extremities to enhance venous return in the treatment of hemorrhagic shock. This action was thought to cause an 'autotranfusion' to the central circulation, increasing right and left ventricular preloads, stroke volume, and cardiac output (CO)."  It would, thus, increase a patients blood pressure.  (1, page 449)

Use of Trendelenburg for raising blood pressure was questioned during the 1950s, but it became widespread anyway as a "mainstay of resuscitation."  Recently there have been studies that show the position does increase blood pressure, although the effect is only short term.  (1, page 449)

Figure 3 -- Old depiction of trendelenburg (2)
Halm notes that most studies conclude that "Trendelenburg position does not lead to beneficial changes in blood pressure or CO/CI (cardiac output, cardiac index, which are more technical terms for blood pressure).  As a result, this position is probably not useful in rescue efforts.  The associated hemodynamic effects are small and unsustained and thus are unlikely to have a clinically significant impact on hypotensive patients."

The study results, Halm writes, conclude that it's better to use other methods of increasing blood pressure, such as:
  • Fluid boluses
  • Pharmacological therapies
  • Other devices targeted to the cause of hypotension
Yet like any other procedure used by the medical profession, physicians aren't going to stop using something they've been doing for a long time.  Regardless of the evidence, physicians are going to continue doing what they were taught, especially when it's as easy as pushing a button, and especially if it makes them feel they are doing something productive.

Yet Halm notes that this might not be such a good idea, because trendelenburg position can be "associated with harmful cardiopulmonary, neurological, and vascular effects, especially in the presence of disease." (1, page 451)

Side effects of trendelenburg include:
  • Anxiety
  • Restlessness
  • Onset of pounding headache
  • Progressive dyspnea
  • Loss of cooperation
  • Hostile patient
  • Struggling efforts to sit upright
Although, it would seem that many of these side effects would result in a ticked off patient, something that would almost assuredly increase blood pressure.  I once had a doctor order BiPAP for a patient just because he thought it would tick the patient off, thereby raising his blood pressure. It didn't work, but it must have made him feel important. I'm being facetious here, but sometimes that's just how it is in the medical profession.

Halm notes that "the position should be used with caution even when immediate/transient benefits are desired."  And I would have to add that the ethics of doing something that has no proven long term effect may work to the disadvantage of therapy.

Usually, however, for the patients I've seen put in trendelenburg, they are usually so sick they don't care; they just want the nurses and doctors to do what they think is necessary to get them feeling better.

I personally think the only time the position would be harmful is when you have a patient in respiratory distress with a low blood pressure.  The temporary rise of blood pressure may come at the expense of making breathing exceedingly more difficult and uncomfortable. But that's just a side thought.

All this said, I have never had a patient complain about being in this position, and usually there sick enough, or medicated enough, not to care.  So chances are pretty good, if you end up in a hospital with a low blood pressure, you'll be asked to lie back, and your bed will be put in trendelenburg.

  1.  Halm, Margo A., RN, "Trendelenbug Position: 'Put to Bed' or Angled Toward Use in Your Unit," American Journal of Critical Care, November, 2012, Volume 21, No. 6, page 449-452,
  2. "Trendelenburg Position,",, accessed 2/24/2016
  3. "Fredrich Trendelenburg,", accessed 2/24/16

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