From the Guidelines
The Trendelenburg position is not recommended for routine use in critically ill patients due to its potential to worsen respiratory function and increase intracranial pressure, and instead, the anti-Trendelenburg position is suggested for upper body elevation in patients with elevated intraabdominal pressure or at its risk. The Trendelenburg position, where the patient lies supine with their head lower than their feet at a 15-45 degree angle, was traditionally used to improve central blood flow during hypotension and shock, but current evidence does not support this practice 1. In fact, it may worsen respiratory function by pushing abdominal contents against the diaphragm, potentially decreasing lung capacity and oxygenation. For hypotension management, fluid resuscitation, vasopressors, and treating the underlying cause are more effective approaches.
Clinical Applications
The Trendelenburg position does retain utility in specific clinical scenarios, including:
- Central venous catheter placement (by distending neck veins)
- Certain surgical procedures (to improve visualization of pelvic structures)
- Occasionally to assist with the reduction of air embolism by trapping air in the right ventricle When implementing this position, clinicians should limit duration to minimize respiratory compromise, continuously monitor vital signs, ensure proper padding to prevent nerve compression, and avoid use in patients with increased intracranial pressure, respiratory distress, or certain cardiac conditions.
Physiological Effects
The physiological effects of this position include increased venous return from the lower extremities, but this benefit is often offset by compensatory vascular responses and the negative respiratory effects. The recent guideline on positioning and early mobilisation in the critically ill by an expert panel suggests avoiding upper body elevation with flexion of the knees and hips in patients with elevated intraabdominal pressure or at its risk and favouring the anti-Trendelenburg position for upper body elevation 1.
Recommendations
In summary, the anti-Trendelenburg position is preferred over the Trendelenburg position for upper body elevation in critically ill patients, especially those with elevated intraabdominal pressure or at its risk, due to its potential to improve respiratory function and reduce the risk of complications 1. Clinicians should carefully consider the individual patient's needs and medical condition before using the Trendelenburg position, and prioritize alternative positioning strategies that promote optimal respiratory and hemodynamic function.
From the Research
Trendelenburg Position Efficacy
The Trendelenburg position is a surgical posture that has been widely used to improve access to pelvic pathology and to treat shock. The efficacy of this position has been studied in various contexts, including its ability to detect bleeding points and prevent postoperative complications.
- The study by 2 found that the Trendelenburg position is superior to the Valsalva manoeuvre in identifying bleeding vessels at haemostasis, with a significantly greater number of bleeding vessels detected in the Trendelenburg position.
- However, the study by 3 suggests that the Trendelenburg position may be potentially harmful in certain circumstances, such as in patients with cardiac, pulmonary, ocular, and central nervous system pathology.
- A meta-analysis by 4 found that the steep Trendelenburg position does not seem to affect postoperative complications, including venous thromboembolism, cardiac, and cerebrovascular complications.
- The study by 5 provides an overview of the historical background and clinical applications of the Trendelenburg position, including its effects on physiological functions and strategies for preventing and managing associated complications.
- The study by 6 found that the reverse Trendelenburg position may reduce intraoperative blood loss during endoscopic sinus surgery, although the presence of polyp, non-fungal sinusitis, and use of microdebrider may exhibit a significant higher blood loss rate.
Factors Influencing Efficacy
Several factors may influence the efficacy of the Trendelenburg position, including:
- Patient physiology and underlying medical conditions 3, 4
- Surgical procedure and technique 2, 6
- Angle and duration of tilt 2, 4
- Use of adjunctive measures, such as hemostatic agents 6
Clinical Applications
The Trendelenburg position has various clinical applications, including: