[Cardiorespiratory effects of perioperative positioning techniques]

Area of Science:

• Anesthesiology
• Surgical Positioning
• Patient Physiology

Background:

• The supine position is standard in surgery, but alternative positions cause significant physiological changes.
• These alterations can affect anesthetic management and surgical outcomes.
• Hemodynamic stability is a primary concern due to altered blood flow and volume distribution.

Purpose of the Study:

• To review the pathophysiological principles of patient positioning during surgery.
• To discuss the hemodynamic and respiratory effects of various surgical positions.
• To present strategies for avoiding complications associated with non-supine positioning.

Main Methods:

• Literature review of pathophysiological effects of surgical positions.
• Analysis of hemodynamic and respiratory alterations.
• Discussion of adverse events and risk reduction strategies.

Main Results:

• Head-down (Trendelenburg) positions can cause relative hypervolemia but impair pulmonary function and increase intracranial pressure.
• Upright (beach chair) positions lead to relative hypovolemia and reduced cardiac output.
• Prone and lateral decubitus positions generally have minimal impact on homeostasis, though left lateral positioning in Cesarean sections is debated.

Conclusions:

• Non-supine patient positioning necessitates careful consideration of physiological impacts.
• Understanding these effects is crucial for mitigating risks like hemodynamic instability and respiratory compromise.
• Proactive management strategies can help prevent severe adverse events during surgery.