Patient Safety

Safe in bed

Patient safety is the key element in the design of hospital beds. Middle East Health looks at US FDA guidelines to avoid patient entrapment in hospital beds.


The US FDA has issued a series of guidelines on appropriate hospital bed design to avoid patient entrapment, which, in the United States alone, has resulted in hundreds of deaths and injuries in the past two decades.

Patients may have problems with memory, sleeping, incontinence, pain, uncontrolled body movement. They may try get out of bed and walk unsafely without assistance. These events can lead to patients injuring themselves if they fall from the bed or fall when trying to walk without assistance. Historically, physical restraints such as vest, ankle or wrist restraints were used to prevent patients injuring themselves. However, these have generally been done away with and replaced with bed rails.

Bed rails, themselves have benefits and risks and the FDA encourages healthcare providers to assess patients’ needs and to provide patient care without restraints.

The FDA says that most patients can be kept in bed without bed rails and asks healthcare workers to consider the following:
● Use beds that can be raised and lowered close to the floor to accommodate both patient and healthcare worker needs
● Keep the bed in the lowest position with wheels locked
● When the patient is at risk of falling out of bed, place mats next to the bed, as long as this does not create a greater risk of accident
● Use transfer or mobility aids
● Monitor patients frequently
● Anticipate the reasons patients get out of bed such as hunger, thirst, going to the bathroom, restlessness and pain; meet these needs by offering food and fluids, scheduling ample toileting, and providing calming interventions and pain relief.

When bed rails are used the FDA recommends that one or more sections of the bed rail, such as the foot rail, be lowered; a mattress with raised foam edges should be used to prevent patients from being trapped between the mattress and rail; and gaps between the mattress and rail should be reduced.

The FDA’s guidelines entitled Hospital Bed System Dimensional and Assessment Guidance to Reduce Entrapment identifies special issues associated with hospital bed systems and provides design recommendations for manufacturers of new hospital beds and suggestions for healthcare facilities on ways to assess existing beds. The guidance characterises the body parts at risk for entrapment, identifies the locations of hospital bed openings that are potential entrapment areas, recommends dimensional criteria for new hospital bed systems, provides information about reporting entrapment adverse events and includes a description of recommended test methods for assessing gaps in hospital bed systems.

On the Web

● The document – Hospital Bed System Dimensional and Assessment Guidance to Reduce Entrapment – is available online here:

● The document – Clinical guidance for the assessment and implementation of bed rails in hospitals, long term care facilities, and home care settings – can be downloaded here:

● Several FDA documents related to hospital bed safety are available here:
Key body parts at risk

Three key body parts at risk for life-threatening entrapment in the seven zones of a hospital bed system discussed in this guidance are the head, neck, and chest. International anthropometric data references have been used to determine the relative sizes of these body parts for the population at greatest risk for entrapment and to provide a guide for the dimensional limits that would reduce their risk of entrapment.


To reduce the risk of head entrapment, openings in the bed system should not allow the widest part of a small head (head breadth measured across the face from ear to ear) to be trapped. Country-specific anthropometric data show that a 1st percentile female head breadth may be as small as 95 mm. A dimension of 120 mm encompasses the 5th percentile female head breadth in all data sources used to develop these recommendations, and includes 1st percentile female head breadth as reported in some data sources.  FDA is therefore using a head breadth dimension of 120 mm as the basis for its dimensional limit recommendations. This dimension is consistent with the dimensions recommended by the Hospital Bed Safety Workgroup (HBSW).


To reduce the risk of neck entrapment, openings in the bed system should not allow a small neck to become trapped.

Data show a 1st percentile female neck diameter of 79 mm [5th percentile = 83 mm]. Several factors, such as neck compressibility, loss of muscle mass in the neck when people age, and the asymmetrical shape of the neck, support the use of a reduced measurement. For example, one published estimate for compressibility of neck tissue is 25% of the uncompressed measure. Reducing the 79 mm measure by approximately 25% to account for tissue compression gives a measure of 60 mm. The HBSW recommend a dimensional limit of 60 mm to prevent neck entrapment. Consistent with these recommendations, FDA is recommending 60 mm as an appropriate dimension for neck diameter.


The openings in a bed system should be wide enough not to trap a large chest through the opening between split rails. For purposes of the recommendations in this guidance, a 95th percentile male chest depth is used to represent the largest chest measure. Although one would assume that the largest chest size belongs to women, breast tissue is compressible and diminishes in size as aging occurs. Male chests, however, have less compressible tissue and do not diminish as significantly in size with aging. A 95th percentile male chest depth of 318 mm, measured from the nipple to the back, including the pectoral muscles, is used to represent the largest chest measure.

● Source: Hospital Bed System Dimensional and Assessment Guidance to Reduce Entrapment - Guidance for Industry and FDA Staff  

ate of upload: 16th May 2009

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