When I first started my nursing career in the early 1990s, I remember watching my preceptor in the critical care unit reflexively place her patient in the Trendelenburg position during episodes of acute hypotension and shock. She explained that lowering the patient’s head and elevating the legs above the heart helped to move blood from the lower extremities to the heart, brain and other vital organs. It certainly made logical sense and seemed to work, at least transiently. I quickly integrated Trendelenburg into my everyday practice. However, researchers found that the use of Trendelenburg does not improve blood pressure and shock and instead, could have detrimental effects on specific patient populations.

The origins of Trendelenburg trace back to the late 1800s, when Dr. Friedrich Trendelenburg, a surgeon, pioneered this technique to gain better access to pelvic organs during operative procedures. During World War I, the position was utilized in the treatment of shock to increase circulation to the heart, increase cardiac output, and improve blood flow to the vital organs (Shammas & Clark, 2007). Also known as autotransfusion, Trendelenburg became common practice in various healthcare settings such as emergency rooms, operating rooms, post-anesthesia care units, and critical care.  The controversy lies in whether blood moving from the extremities to the central part of the body contributes to hemodynamic stability and whether there are harmful effects that outweigh benefits. Potential adverse effects include increases in intracranial pressure, decreased lung expansion/lung volumes caused by pushing the diaphragm upward, baroreceptor effects promoting a false sensation that blood flow improved which leads to vasodilation, and a decreased response to the hypotensive state (Shammas & Clark, 2007).  

Trendelenburg is currently recommended by the American Society of Anesthesiologists as the optimal position for central line insertion, when clinically appropriate and feasible, to facilitate cannulation and prevent the occurrence of air embolisms. However, while the technique has been widely employed to treat hypotension, medical and nursing societies have not developed guidelines supporting the use of Trendelenburg to treat shock. Shammas and Clark (2007) as well as Bridges and Jarquin-Valdivia (2005) reviewed several studies that evaluated the effects of Trendelenburg positioning. Research findings are summarized below.

• Sibbald, Paterson, Holliday, and Baskerville (1979) found that Trendelenburg did not consistently improve hemodynamic effects in critically ill hypotensive patients. 
• Gentili, Benjamin, Berger, and Iberti (1988) published the one study concluding that Trendelenburg may improve cardiac function by increasing cardiac output (CO), mean arterial pressure (MAP), and central venous pressure. However, they were investigating the safety of the position and included patients who were not hypotensive.
• Ostrow, Hupp and Topjian (1994) found no significant effect on CO, cardiac index (CI), partial pressure of oxygen (PO2), systemic vascular resistance (SVR) or MAP from either Trendelenburg or modified Trendelenburg (legs elevated 30 degrees). 
• Terrai, Anada, Masushima, Shimizu, and Okada (1995) evaluated the effects of a 10-degree head-down-tilt Trendelenburg position on central hemodynamics and flow through the internal jugular vein. Results showed an increase in left ventricular end-diastolic volume (LVEDP), stroke volume (SV), and CO (increased 16%) with a reduced heart rate after 1 minute of 10-degree Trendelenburg position. After 10 minutes, the hemodynamic changes returned to pre-intervention levels. 
• Fahy et al. (1996) studied the effect of Trendelenburg on lung mechanics. They concluded that Trendelenburg did not increase intrathoracic pressures but did affect lung and chest wall movement that resulted in reduced lung volumes. This effect may be due to the shifting of the abdominal organs and contents toward the diaphragm. They surmised that the intervention may have a greater adverse effect on patients with increased body mass index and those with lung disease. 
• Reuter et al. (2003) found that Trendelenburg positioning slightly increased preload volume and caused a small autotransfusion effect but it did not significantly improve cardiac function. 
• Bertolissi, Broi, Soldano, and Bassi (2003) evaluated the use of the passive leg elevation (PLE) technique in coronary artery bypass graft (CABG) patients. They found PLE worsened the condition of patients with a reduced right ventricular end-diastolic volume and therefore concluded that PLE should be used with caution in this patient population.

While these studies consisted of small sample sizes and quasi-experimental designs without randomization or control groups, several strong conclusions can be made (Shammas & Clark, 2007). 

• The research does not support the use of Trendelenburg as an intervention for hypotension.
• Trendelenburg should be avoided until larger studies are conducted as it may increase a patient’s risk for hemodynamic compromise, elevated intracranial pressure, and impaired lung mechanics.
• Specific patient populations should not be placed in Trendelenburg including those with:
  • Decreased RVEF
  • Pulmonary disorders
  • Head injuries
• Interventions that are successful in treating hypotension include vasopressors, inotropic agents, intravascular volume, and cardiac assist devices.

Trendelenburg is no longer a part of my routine practice. It is important for clinicians to stay up to date on the latest research and be sure they are not perpetuating outdated patient management techniques that are potentially harmful to some patients. Further research would be required on the utilization and safety of Trendelenburg before it could be incorporated into practice guidelines and as a standard of care. Are you still using Trendelenburg to treat your hypotensive patients?

References
Bertolissi, M., Broi, U.D., Soldano, F., & Bassi, F. (2003). Influence of passive leg elevation on the right ventricular function of coronary patients. Critical Care, 7(2), 164-170.

Bridges, N. & Jarquin-Valdivia, A.A. (2005). Use of the Trendelenburg position as the resuscitation position: To T or not to T? American Journal of Critical Care, 14(5), 364-368.

Fahy, B.G., Barnas, G.M., Nagle, S.E., Flowers, J.L., Njoku, M.J. & Agarwal, M. (1996). Effects of Trendelenburg and reverse Trendelenburg postures on lung and chest wall mechanics. Journal of Clinical Anesthesia, 8(3), 236-244.

Gentili, D.R., Benjamin, E., Berger, S.R., & Iberti, T.J. (1988). Cardiopulmonary effects of the head-down tilt position in elderly postoperative patients: a prospective study. Southern Medical Journal, 81(10), 1258-1260.

Ostrow, C.L., Hupp, E. & Topjian, D. (1994). The effect of Trendelenburg and modified Trendelenburg positions on cardiac output, blood pressure, and oxygenation: a preliminary study. American Journal of Critical Care, 3(5), 382-386.

Reuter, D.A., Felbinger, T.W., Schmidt, C., Moerstedt, K., Kliger, E., Lamm, P. & Goetz, A.E. (2003). Trendelenburg positioning after cardiac surgery: effects on intrathoracic blood volume index and cardiac performance. European Journal of Anaesthesiology, 20(1), 17-20. 

Shammas, A. & Clark, A. (2007). Legal and Ethical: Trendelenburg positioning to treat acute hypotension: Helpful or harmful? Clinical Nurse Specialist: The Journal for Advanced Nursing Practice, 21(4), 181-187.

Sibbald, W.J., Paterson, N.A., Holliday, R.L. & Baskerville, J. (1979). The Trendelenburg position: hemodynamic effects in hypotensive and normotensive patients. Critical Care Medicine, 7(5), 218-224.

Terrai, C., Anada, H., Masushima, S., Shimizu, S., & Okada, Y. (1995). Effects of Trendelenburg on central hemodynamics and internal jugular vein velocity, cross-sectional area, and flow. American Journal of American Medicine, 13, 255-258.