The Beach Chair Position (BCP) is a modification of the standard supine position, placing the patient in a semi-recumbent, seated posture for specific surgical procedures. This technique involves elevating the patient’s torso, shifting the body from lying flat to a reclined sitting position. The BCP, sometimes referred to as the semi-Fowler position, is employed to enhance the surgeon’s access and visibility to the operative area. The vertical orientation of the body introduces unique physiological considerations for patient safety during the operation.
Visualizing the Position and Patient Setup
The physical setup of the Beach Chair Position mimics a reclined chair, with the patient’s torso typically elevated between 30 and 70 degrees. The hips and knees are usually flexed, often with the feet supported by a foot bar for stability. A specialized surgical table or attachment is used to achieve this seated posture, ensuring the head, neck, and torso are maintained in neutral alignment. Meticulous padding is required beneath the calves, knees, and elbows to prevent pressure injuries to nerves and skin. The patient’s head is secured with a headrest, and the trunk is secured with safety belts or tape to maintain a steady position throughout the surgery.
Primary Surgical Applications
The Beach Chair Position is most frequently adopted for orthopedic procedures, particularly those involving the shoulder. For surgeries like shoulder arthroscopy or open rotator cuff repairs, this seated position provides superior visualization of the joint. Gravity assists the surgeon by causing the arm to hang naturally, which helps to distract the joint and improve the working space. The upright posture also allows the surgeon to easily examine the shoulder’s range of motion during the operation to assess the repair. Beyond shoulder procedures, the BCP is also used in certain facial, cranial, and cervical spine surgeries, where the elevated position can improve venous drainage and reduce bleeding.
Managing Hemodynamics in the Beach Chair Position
One of the unique challenges of the Beach Chair Position is managing the patient’s cardiovascular system, specifically blood pressure and cerebral perfusion. When the patient moves to a seated position, the vertical distance between the heart and the brain increases significantly. This height difference creates a hydrostatic pressure gradient, meaning the blood pressure measured at the arm is higher than the actual pressure perfusing the brain. For example, because the brain is elevated 10 to 30 centimeters above the arm cuff, the brain’s mean arterial pressure (MAP) can be 8 to 24 mmHg lower than the measured arm pressure. This difference can lead to cerebral hypoperfusion, where blood flow to the brain is inadequate, especially when combined with the blood pressure-lowering effects of general anesthesia.
Anesthesia providers must rigorously monitor and manage blood pressure to ensure adequate cerebral perfusion pressure (CPP). To accurately reflect the pressure reaching the brain, the blood pressure measurement site, such as the arm cuff or an invasive arterial line, is often leveled with the external acoustic meatus (ear canal). Maintaining the brain’s blood pressure above a predetermined threshold, often 70 mmHg, helps to prevent cerebral desaturation events. The use of medications to support blood pressure is common, and continuous monitoring of cerebral oxygenation with near-infrared spectroscopy (NIRS) is recommended to detect any drops in oxygen saturation early.