A bed-bound resident is an individual unable to change their position independently, remaining confined to a bed for extended periods. Repositioning is the systematic practice of moving this individual into a different orientation to redistribute body weight. This fundamental intervention is a core component of preventive care, designed primarily to maintain skin integrity and promote healthy circulation.
Understanding the Two-Hour Standard
The standard protocol for most bed-bound individuals is repositioning at least every two hours, a schedule often referred to as “q2h.” This timing is based on the physiological limits of human tissue under sustained pressure. The primary mechanism driving this schedule is the concept of capillary closing pressure, the external force required to collapse the smallest blood vessels.
Healthy tissue requires a continuous supply of oxygen and nutrients. When sustained external pressure exceeds the arterial capillary pressure, typically cited around 32 millimeters of mercury (mm Hg), the blood flow is cut off. If this pressure is not relieved, the cells become starved of oxygen, a condition known as cellular hypoxia. This lack of blood flow can lead to cell death and tissue necrosis, which marks the beginning of a pressure injury. Repositioning every two hours acts as a baseline to ensure the pressure is relieved before irreversible tissue damage occurs.
The Science of Tissue Damage (Pressure Injuries)
Inadequate repositioning results in a Pressure Injury (commonly known as a pressure ulcer or bedsore). These injuries develop from two main forces: direct pressure and shearing. Pressure is the vertical force of body weight compressing the tissue between a bony prominence and the external surface of the bed.
Shearing occurs when the skin remains stationary against the sheet while the underlying bone and muscle slide in the direction of gravity, such as when the head of the bed is elevated. This sliding action stretches and tears the blood vessels, causing localized tissue damage. Muscle tissue is particularly vulnerable and is often damaged before the visible skin layers show signs of injury.
Pressure injuries tend to form over areas where bone is close to the skin surface, as there is less protective tissue to distribute the force. High-risk anatomical areas include the sacrum (tailbone), the heels, the hips (trochanters), the elbows, and the back of the head (occiput). A Stage 1 Pressure Injury is characterized by intact skin with non-blanchable redness; in darker skin tones, the area may appear a different color, such as purple or brown. A Stage 2 injury involves a partial-thickness loss of the epidermis and dermis, presenting as a shallow open ulcer or a fluid-filled blister. These visible stages indicate that the current repositioning schedule or technique is insufficient to protect the tissue.
Techniques for Safe Repositioning
Safe repositioning focuses on minimizing friction and shear forces. Caregivers should always lift the resident rather than drag or pull them across the bed linens. Mechanical aids, such as draw sheets or slide sheets, should be placed beneath the resident to facilitate this lifting action.
A highly recommended technique is the 30-degree lateral side-lying position. This angle positions the body on a fleshy part of the hip and shoulder, effectively offloading pressure from the prominent bony areas like the greater trochanter and the sacrum. Wedges or pillows are used to maintain this angle and prevent the resident from rolling onto a 90-degree position, which places direct pressure on the hip bone.
Ensure the heels are completely offloaded from the mattress in any position, as they are a frequent site of injury. Pillows or specialized heel protectors can elevate the lower legs to suspend the heels in the air. Comprehensive documentation of the exact time and position change (e.g., “30-degree right lateral tilt”) must be charted to ensure the schedule is consistently maintained.
When Repositioning Frequency Must Change
The two-hour standard serves as a minimum, but a resident’s clinical status may necessitate a more frequent schedule. Individuals with existing Stage 1 or Stage 2 pressure injuries, poor nutritional status, dehydration, or conditions like diabetes and vascular disease have severely compromised tissue tolerance. For these residents, repositioning may need to occur hourly to prevent injury progression.
Conversely, some modern support surfaces can safely extend the time between position changes. Specialized pressure-redistributing mattresses (such as low-air-loss or alternating pressure surfaces) continuously adjust pressure points. A clinical assessment may determine that a three- or four-hour repositioning interval is acceptable. However, these devices are a supplement to, not a replacement for, regular turning.