Anesthesia Considerations 

Beach Chair Position

 

 

Background

 

• Beach chair or sitting positioning

• Used for post fossa craniotomy, post c-spine surgery, shoulder surgery

 

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Physiologic Effects of Sitting Position ​

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• CNS

  • ↓  cerebral perfusion

    • correct MAP for hydrostatic diffn b/w BP cuff  & brain; place transducer @ level of external auditory meatus if art line

      • 1 cm rise = 0.75 mmHg drop in MAP

    • Compounded by effects of GA & sitting position on cerebral autoregulation

  • Possible cerebral O2 desaturation (unrelated to hemodynamics)

• CVS

  • Venous pooling in lower extremities -->  ↓ preload, SV, MAP, CO (~20%), & CPP

    • Mitigated w/ IV fluids, flexing hips w/ legs elevated, compression stockings, gradual head elevation

• Respiratory

  • ↑ FRC, lung compliance

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Potential Complications 

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• Nerve injuries

  • Brachial plexus, ulnar nv, & sciatic nv can be stretched/compressed

  • Spinal cord injury - if sig neck flexion

• Pressure injury over ischial tuberosity

• Excessive neck flexion - vascular obstruction in neck, kinking/obstruction of ETT/SGD, tongue/oropharyngeal swelling

• Venous air embolism

• Pneumocephalus

• Stroke, ischemic brain injury, and death

 

References

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• Breyer, KEW, Roth, S. (2020) Chapter 34: Patient Positioning and Associated Risks. In Miller’s Anesthesia, 9th Ed. Elsevier. p1079-1112.e6