Managing Perfusion During Procedures in the Beach Chair Position

Managing Perfusion During Procedures in the Beach Chair Position

The beach chair position is widely used in upper extremity surgeries, such as shoulder arthroscopy and rotator cuff repair, for its surgical advantages—improved shoulder exposure, reduced risk of brachial plexus injury, and better airway access for anesthesiologists. However, the semi-upright nature of the beach chair position (typically 45–70° incline) introduces significant perfusion challenges, especially during general anesthesia1.

Under anesthesia, the body’s natural blood pressure regulation mechanism, the autonomic baroreceptor response, is suppressed. When patients move from lying flat to sitting up, blood pools in their lower extremities, reducing blood flow to the brain. This decrease in pressure between the heart and brain (the hydrostatic gradient) can lead to cerebral desaturation events (CDEs), which are brief but potentially dangerous periods of reduced brain oxygenation1.

Though uncommon, severe neurologic complications including stroke, brain death, vision loss, and death have occurred as a result of insufficient perfusion during surgeries in the beach chair position. A systematic review by Salazar et al. found these complications most frequently occur with hypotensive anesthesia, a technique used to reduce bleeding that can dangerously compromise brain perfusion when positioning is not appropriately considered1.

Standard brachial cuff measurements overestimate cerebral perfusion pressure due to the “waterfall effect” (the vertical distance between brain and heart), producing a discrepancy that makes it challenging to detect dangerously low brain perfusion levels1. Therefore, to monitor perfusion in the beach chair position, near-infrared spectroscopy (NIRS) offers real-time, noninvasive monitoring of brain oxygenation by measuring changes in hemoglobin 2.5 cm below the scalp. Reflecting mostly venous saturation (~70–75% of cerebral blood volume), NIRS is an FDA-approved, cost-effective technique widely used in high-risk surgeries to detect cerebral ischemia2.

To optimize perfusion in patients under anesthesia in the beach chair position, clinicians can employ three main strategies: hemodynamic management, ventilation adjustments, and careful anesthetic technique and positioning.

Hemodynamic management during surgery in this position relies on a combination of fluid therapy and vasopressor support. Preemptive fluid administration, such as fixed-volume intravenous boluses, helps maintain adequate preload, thereby improving cardiac output and mean arterial pressure (MAP) through volume expansion3. Vasopressors like phenylephrine can complement this by increasing MAP via vasoconstriction; however, they may reduce cardiac output through reflex bradycardia, sometimes necessitating inotropic support. Evidence suggests that combining fluid and vasopressor boluses is more effective at sustaining optimal MAP, cardiac output, and stroke volume than either intervention alone3. Ventilation strategies also play a key role. Elevating inspired oxygen concentration and end-tidal CO₂ enhances regional cerebral oxygenation, independent of the anesthetic regimen4,5.

Ultimately, perfusion management in the beach chair position demands more than standard monitoring. Integrating NIRS for real-time cerebral oxygenation tracking, along with tailored fluid, vasopressor, and ventilation strategies, is essential for reducing the risk of cerebral ischemia and optimizing patient outcomes.

References

  1. Salazar DH, Davis WJ, Ziroğlu N, Garbis NG. Cerebral desaturation events during shoulder arthroscopy in the beach chair position. JAAOS Glob Res Rev. 2019;3(8):e007. doi:10.5435/JAAOSGlobal-D-19-00007
  2. Pant S, Bokor DJ, Low AK. Cerebral oxygenation using near-infrared spectroscopy in the beach-chair position during shoulder arthroscopy under general anesthesia. Arthroscopy. 2014;30(11):1520-1527. doi:10.1016/j.arthro.2014.05.042
  3. Frey S, de Wild M, Hautz WE, et al. Prophylactic fluid boluses in the beach chair position: a randomized controlled trial. J Anesth. 2020;34(5):697–706. doi:10.1007/s00540-020-02782-3.
  4. Picton W, Rajakulendran Y, Mavrovi E, et al. Near-infrared spectroscopy in the beach-chair position: a prospective observational study. Bone Joint J. 2020;102-B(6):735–741. doi:10.1302/0301-620X.102B6.BJJ-2019-1402.R1.
  5. Gilotra M, O’Brien MJ, Srikumaran U, et al. Hypotensive bradycardic events during shoulder arthroscopy in the beach-chair position: a prospective analysis of frequency and associated factors. J Shoulder Elbow Surg. 2013;22(10):e1–e6. doi:10.1016/j.jse.2013.03.009.