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Three Part Question

In [adults with hypotension] does the [Trendelenburg position] improve [hemodynamics]?

Clinical Scenario

A 28 year old male with a gunshot wound to the leg presents to the emergency department in hypovolemic shock. Among other things, you place the patient in the Trendelenburg position, with the body tilted so that the feet is higher than the head. You wonder whether this position actually improves hemodynamics.

Search Strategy

Medline and Embase databases searched via OvidSP interface in June 2010.
[shock.mp OR hypovol$.mp OR hypotensi$.mp] AND [trendelenburg.mp OR head-down tilt.mp] LIMIT to English language and humans.

Search Outcome

Two hundred and ninety-four papers were found, of which five were considered relevant to the question

Relevant Paper(s)

Author, date and country	Patient group	Study type (level of evidence)	Outcomes	Key results	Study Weaknesses
Sing RF, et al, 1993, USA	Eight consecutive hypovolemic adults were studied. All patients were postoperative admissions to the surgical ICU	Non-randomized controlled trial	Oxygen Delivery (Supine vs. Trendelenburg)	No significant change	Small sample size. Two patients were given metoprolol and dobutamine for postoperative complications.
			Cardiac Index (l/min/m2)	No significant change
			Mean Arterial Pressure by radial artery catheter	Increased from 64.9–75.6 mm Hg, p<0.05
Miyabe M et al, 1993, Japan	40 Female patients undergoing major gynaecological surgery with spinal anaesthesia. Patients were put in head-tilt position for 10 min following spinal anaesthetic	Observational study	Systolic Blood Pressure (Severe hypotensive patients)	SBP decreased by 24% after the spinal block. There was a non-significant increase in the average blood pressure of the group to 22–24% below the initial level	No control group. Different population from patients presenting to emergency departments
Sibbald WJ, et al, 1976, Canada	61 normotensive and 15 hypotensive patients with acute cardiac illness or sepsis	Non-randomized controlled trial	Mean Arterial Presure (Hypotensive Patients)	No significant increase	Small number of patients with the target condition
			Cardiac Index (Hypotensive Patients)	No significant increase
Reuter DA, et al, 2003, Germany	12 Ventilated patients with hypovolaemia suggested by trans-oesophageal echo were positioned 30° head-down for 15 min	Observational study	MAP and cardiac index as determined by invasive monitoring	No significant difference in either MAP or cardiac index on assuming head-down tilt. There was a significant drop in each on returning the patients to the supine position	Small study with no control group
Taylor and Well, 1967, USA	11 Patients from a single hospital. 54 Patients had significant hypotension due to a variety of reasons, five patients were critically unwell but normotensive at the time	Observational study	Arterial pressure and cardiac index were measured invasively using catheters during a 20 min period of head-down tilt	In six/seven patients with hypotension (one patient tested twice) the arterial pressure decreased. It increased in the other patient. No significant change in the normotensive patients No change in cardiac index on assuming head-tilt but non-significant increase on reverting to horizontal in all patients	Small number of selected patients with different underlying aetiologies for their condition

Comment(s)

The Trendelenburg position was originally described by Freidrich Trendelenburg as a method of improving the surgical field view during laparotomy. It was suggested as a method of improving cardiac output in patients with shock during the First World War by Walter Cannon, although he later decided it was not beneficial. The theory was that gravity would aid the venous return of blood to the central circulation and improve cardiac output. Despite any evidence of benefit and the fact that its original propagator rescinded his recommendation, the idea has remained popular, perhaps because the idea appears logical in a purely mechanical sense. The Trendelenburg position is advocated for hypotensive patients secondary to a wide selection of drug overdoses on the UK Poisons Information Service website, and most first-aid texts advocate leg elevation for patients who have fainted.

Several studies were found that examined the cardiovascular effect of a downward head-tilt position in patients with a compromised vascular system. The studies all involved small numbers of patients who had hypotension due to a variety of aetiologies and all have some methodological flaws. The one thing that all of the included studies has in common is a failure to demonstrate any benefit of the Trendelenburg position on cardiac output. There is some suggestion that it may even have a detrimental effect apparent on returning the patient to a supine position.

Editor Comment

MAP, mean arterial pressure; SBP, systolic blood pressure.

Clinical Bottom Line

There is no evidence of benefit in using the Trendelenburg position for patients with hypotension and this practice is not recommended.

http://www.mayoclinic.com/health/first-aid-fainting/FA00052

http://www.patient.co.uk/doctor/Common-First-Aid-Procedures-in-General-Practice.htm

http://archive.student.bmj.com/issues/05/05/education/183.php

http://toxbase.co.uk/

References

1. Sing RF, O'Hara D, Sawyer MAJ et al. Trendelenburg Position and Oxygen Transport in Hypovolemic Adults. Ann Emerg Med March 1994; 23:564-567.
2. Miyabe M, Namiki A. The Effect of Head-down Tilt on Arterial Blood Pressure After Spinal Anesthesia Anesth Analg 1993;76:549-552.
3. Sibbald WJ, Paterson NA, Holliday RL et al. The Trendelenburg Position: Hemodynamic Effects in Hypotensive and Normotensive Patients. Crit Care Med 1979;7:218-224.
4. Reuter DA, Felbinger TW, Moerstedt, Kilger E et al. Trendelenburg Positioning After Cardiac Surgery: Effects on Intrathoracic Blood Volume Index and Cardiac Performance Eur J Anaesthesiol 2003;20:17-20.
5. Taylor J. Weil MH. Failure of the trendelenburg position to improve circulation during clinical shock. Surg, Gynecol Obstet 1967;124:1005–10.