What is the physiological basis for placing a patient with unilateral lobar consolidation in a lateral decubitus position with the affected side up?

Medical Advisory BoardAll articles are reviewed for accuracy by our Medical Advisory Board
Educational purpose only • Exercise caution as content is pending human review
Article Review Status
Submitted
Under Review
Approved

Last updated: March 10, 2025View editorial policy

Personalize

Help us tailor your experience

Which best describes you? Your choice helps us use language that's most understandable for you.

From the Guidelines

Positioning a patient with unilateral lobar consolidation with the healthy side down (affected side up) is not recommended, instead, a lateral position of about 90° with the healthy side down (good lung down) is suggested to improve gas exchange. This approach is based on the latest guidelines from the expert panel in Intensive Care Medicine 1. The physiological basis for this positioning is to improve ventilation-perfusion matching, which is crucial for optimal oxygenation.

When the healthy lung is positioned downward, gravity directs blood flow toward the healthier, dependent lung, which receives better perfusion. Meanwhile, the consolidated lung, being in the non-dependent position, continues to receive adequate ventilation. This positioning creates a more optimal ventilation-perfusion ratio throughout the lungs, improving overall oxygenation. The use of this positioning strategy is supported by the guideline recommendation 1.5, which suggests performing a lateral position of about 90° with the healthy side down when ventilating patients with unilateral lung damage to improve gas exchange 1.

Additionally, this position can help mobilize secretions from the affected lung through postural drainage, as gravity assists in moving mucus toward the central airways where it can be more effectively coughed up or suctioned out. The technique is particularly beneficial in conditions causing lobar consolidation, such as pneumonia or atelectasis. For implementation, the patient should be positioned at a 90° lateral tilt with the healthy side down for an appropriate duration, ensuring comfort with proper pillow support. This positioning strategy complements other respiratory interventions like deep breathing exercises, incentive spirometry, and appropriate antibiotic therapy when indicated.

Key considerations for positioning include:

  • Regular modification of positioning to avoid the flat supine position, as recommended in guideline 1.6 1
  • Avoiding continuous lateral rotation therapy, as suggested in guideline 1.7 1
  • Carefully examining the areas at risk for pressure ulcers during positioning to minimize the risk of development, as recommended in guideline 2.12 1

From the Research

Physiological Basis for Lateral Decubitus Positioning

The physiological basis for placing a patient with unilateral lobar consolidation in a lateral decubitus position with the affected side up is to improve ventilation-perfusion coupling and reduce secretion burden.

  • The goal of this positioning is to allow the unaffected lung to expand and improve oxygenation, while also helping to reduce the amount of secretions in the affected lung 2.
  • However, studies have shown that the oxygenation response to this maneuver is heterogeneous, and the dependent lung may become derecruited, leading to worsening of the condition 2.
  • In an animal model of mono-lateral pneumonia, positioning the animal in a lateral decubitus position with the healthy lung dependent improved oxygenation, but collapsed the healthy lung, while positioning with the diseased lung dependent further collapsed the diseased lung 2.

Clinical Implications

The clinical implications of lateral decubitus positioning for patients with unilateral lobar consolidation are complex and require careful consideration.

  • Physiotherapists typically rely on lung auscultation and interpretation of chest x-ray (CXR) to inform treatment selection, but these tools lack diagnostic accuracy, which could limit the ability to locate the affected area and select an appropriate treatment position 3.
  • The use of lung ultrasound (LUS) as a reference standard for locating aeration loss has been shown to be more accurate than CXR and lung auscultation, and may be a useful tool for guiding respiratory physiotherapy positioning 3.
  • Studies have shown that physiotherapists do not always deliver appropriate positioning for patients with acute lobar atelectasis, highlighting the need for further education and training on the use of LUS and other diagnostic tools to guide treatment selection 3.

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Appropriateness of respiratory physiotherapy positioning for acute lobar collapse.

Australian critical care : official journal of the Confederation of Australian Critical Care Nurses, 2025

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

Have a follow-up question?

Our Medical A.I. is used by practicing medical doctors at top research institutions around the world. Ask any follow up question and get world-class guideline-backed answers instantly.