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Solutions for Monitoring Cerebral Oximetry During Orthopedic Beach Chair Position

Concerned about cerebral perfusion during beach chair positioning?

Studies have shown that significant cerebral oxygen desaturation events are not infrequent during beach chair position surgery.1 Desaturation events have been associated with post-operative patient nausea, vomiting, cognitive dysfunction and, in rare instances, catastrophic cerebral injury.2

Nonin's SenSmart Cerebral Oximetry System continuously monitors cerebral oxygen saturation, helping surgeons and anesthesiologists prevent cerebral hypo perfusion while they safely optimize the surgical field in beach chair position surgery. On a cost-per-case basis, the SenSmart System can be your most cost-effective, neuro-protective monitoring tool.

The Art

Studies have found that deliberate or accidental hypotension in beach chair position surgery has the potential to result in periods of serious cerebral oxygen desaturation.3 Cerebral ischemia during surgery is associated with post-operative transient or permanent cognitive decline, and may have the potential to slow rehabilitation progress and prolong length of stay.4 In a few cases, cerebral oxygen desaturation has led to catastrophic outcomes, including death.3

Lowering blood pressure safely to clear the surgical field is a common practice used in beach chair intraoperative patient management, but until now, determining adequate cerebral perfusion has been more of an art than a science:

  • How do you know if the intermittent blood pressure taken from an arm cuff is reflective of the second-to-second cerebral perfusion pressure at the brain?
  • How do you know if a given blood pressure is too low or too high for an individual's proper cerebral oxygenation?
  • How do the surgeon and anesthesiologist "referee" their manipulation of blood pressure?
  • How low is too low for patients who live with hypertension?

Electroencephalography (EEG) and Trans-Cutaneous Doppler (TCD) are the methods to monitor brain activity in, and blood flow to, the brain intra-operatively, but neither provides you knowledge of whether the brain tissue is receiving and extracting adequate oxygen. Cerebral oximetry, on the other hand, is simple to use, provides real-time monitoring, and rapidly responds to changes in oxygen supply and demand, alerting the surgical team to impending cerebral desaturation.

"The high prevalence of significant cerebral oxygen desaturation during shoulder surgery in the upright position underlines the need for close monitoring. NIRS [near-infrared spectroscopy] might constitute a valuable technique to detect cerebral hypo perfusion in this high-risk group of patients." 5

The Science

Cerebral oximetry is already widely used in cardiac surgery to monitor for cerebral ischemia, resulting in reduced postoperative cognitive decline.6 Increasingly, anesthesiologists and orthopedic surgeons who perform beach chair procedures are also turning to cerebral oximetry to quickly, easily and accurately monitor the cerebral perfusion of their patients in the upright position.

Nonin Medical's Cerebral Sensmart Oximetry System is non-invasive and easy to use. Put a sensor on the forehead, turn on the monitor and track hemoglobin oxygen saturation of cerebral cortex tissue. When demand exceeds the body’s ability to deliver sufficient oxygen to the brain, hemoglobin saturation declines and the readings on the monitor reflect that decline (and recovery) quickly. The second-to-second continuous view can serve as a first alert that the patient's brain tissue is becoming hypoxic. What you will see in surgery is a confidence-boosting, reliable signal helping you comfirm that your neuro-protective strategies are working.

Nonin SenSmart offers distinct advantages for the beach chair position:

  • Bright, easy-to-read monitor that is light-weight (<1 kg) and pole-mountable for easy portability
  • Intuitive, easy-to-operate user interface with fast signal acquisition delivering readings within seconds of startup and updating every 1.5 seconds - no patient data entry required
  • Sensor cables that allow for easy placement and function in the beach chair position

"Near-infrared spectroscopy (NIRS), a non-invasive optical technology, can be utilized at the bedside to monitor brain oxygenation to detect tissue hypoxia-ischemia, allowing for early intervention and potential prevention of permanent injury." 7

Evaluate the SenSmart System

Evaluate Nonin's SenSmart Cerebral Oximetry System at no cost in beach chair procedures. Contact your Nonin Medical representative today to discuss a free, no-obligation evaluation: 1.800.356.8874 (toll free US and Canada).


1. Murphy GS, Szokol JW, Marymont JH, et al. Cerebral oxygen desaturation events assessed by near-infrared spectroscopy during shoulder arthroscopy in the beach chair and latacubitus positions. Anesth Analg. 2010;111:496-505.

2. Pohl A, Cullen DJ. Cerebral ischemia during shoulder surgery in the upright position: a case series. J Clin Anesth. 2005;17:463-9.

3. Papadonikolakis A, et al. Avoiding catastrophic complications of stroke and death related to shoulder surgery in the sitting position. J Arthrosc and Rel Surg. 2008;24:481-482.

4. Casati, et al. Monitoring cerebral oxygen saturation in elderly patients undergoing general abdominal surgery: a prospective cohort study. Eur J Anes 2006;24:59-65

5. Moerman AT, De Hert SG, Jacobs TF, et al. Cerebral oxygen desaturation during beach chair position. Eur J Anaesthesiol. 2012;29:82-7.

6. Mohandas BS, Jagadeesh AM, Vikram SB. Impact of monitoring cerebral oxygen saturation on the outcome of patients undergoing open heart surgery. Ann Card Anaesth 2013;16:102-6.

7. Kreeger RN, Ramamoorthy C, Nicolson SC, et al. Evaluation of Pediatric Near-Infrared Cerebral Oximeter for Cardiac Disease. Annals Thoracic Surgery. 2012;94:1527-33.

* Actual case. Data on file at Nonin Medical.

** Model 8004CA sensor. Data on file at Nonin Medical.