Bryan Bledsoe, DO, FACEP, recently asked in his column why we rarely see vacuum mattresses in the U.S.„ While American EMS still uses backboards for most spinal immobilization, EMS providers in other countries use vacuum mattresses for this task.
To understand the concept of a vacuum mattress, think of a giant bean bag. A vinyl/nylon body is filled with polystyrene beads (some manufacturers use similar materials). The patient is placed on the vacuum mattress and strapped in. Then providers, through use of the device, pack the beads up against the patient. At least one manufacturer recommends placing a folded towel under the patient's neck to stabilize it if a cervical collar isn't used. After the patient is strapped and packed, the air is removed from the mattress. Straps are readjusted, and you're ready to move or load onto a stretcher.
Some Scientific Findings
A study published in a 1994 British journal hypothesized that using a vacuum mattress would reduce the "incidence of pressure necrosis and the possibility of further neurological compromise." In the study, researchers at Noble's Hospital on the Isle of Man examined the interface pressures between the sacrum, midlumbar spine and various support surfaces: a backboard, a padded backboard and a vacuum stretcher. Sacrum ischemic pressures were much higher on the two backboards than on the vacuum stretcher. An earlier study demonstrated that pressure-wound incidence is higher the longer a patient spends on a backboard. The researchers also felt the total lack of normal lumbar lordosis support from both backboards could lead to further neurological compromise; the vacuum stretcher supported the lumbar lordosis. This was all hypothesis, but worthy of further examination, in their opinion. They also noted that, in 1993, most European countries were using vacuum stretchers, though the UK and North America were not.(1)
Three different studies published in 1996 volumes of the Journal of Emergency Medicine found patients suffered less pain on vacuum mattresses than they did on backboards. Two of the studies found better immobilization with the vacuum mattress; the third only looked at pain experience.(2,3,4)
One of the 1996 studies, "Comparison of a vacuum splint device to a rigid backboard for spinal immobilization," expressed concern about the rigidity of the vacuum mattress: "Even with all the air removed from the device, they are not rigid enough to serve as an extrication device in some situations."(2)
That issue may have been resolved. The Australian manufacturerNeann states in the "Vacuum Splint" section of its Web site that their vacuum mattress "becomes extremely rigid for up to 24 [hours]" after the air is pumped out.
A 2003 study conducted at Royal Hallamshire Hospital, Sheffield, UK, compared stability between a backboard and vacuum mattress.(6) The researchers tilted volunteers on each device placed on an operating table from 45 degrees head up to 45 degrees head down, and then tilted them 45 degrees laterally. "The mean body movements in the head up position (23.3 v 6.66 mm), head down (40.89 v 8.33mm), and lateral tilt (18.33 v 4.26mm) were significantly greater on the backboard than on the vacuum mattress," they said.(5)
In case you're thinking the harsh conditions you work under may be too much for a plastic mattress to endure, here are a few points from the British Services Everest Expedition in 1992. A Sherpa fell 100 feet into an ice fall, a sloping face of a glacier that's similar to a frozen waterfall. He had a severe head injury and suspected spinal injuries. Rescuers pulled him out with a sledge stretcher and Stifneck extrication collar from Laerdal Medical and an Evac-U-Splint mattress from Hartwell Medical Corp. During the 48 hours before a helicopter could reach him, the group experienced inclement weather and sub-zero temperatures. The group commander credited the vacuum mattress's polystyrene filling for the fact that the patient suffered no ill effects from the cold.
Some American agencies are using vacuum mattresses, such as the Mount Desert (Maine) ambulance service. On Aug. 18, rescuers from this service used a full-body vacuum splint to rescue a Massachusetts woman who was injured when she fell over a cliff in Acadia National Park and landed on the rocks below.
But although a few U.S. services use vacuum mattresses, these devices are still uncommon in the U.S. Let us know atJEMS Connectwhy you think vacuum mattresses are not as common in the U.S. as they are in other countries. Is it because of the cost or lack of exposure? Or do agencies continue to use backboards because of traditional thinking (such as "this is the way we've always done it").
Ann Marie Lindstromis a freelance writer and contributing editor to JEMS.