Imagine you’re working on one of your machines, sleuthing for a leak in the hydraulic system, poking around in a bundle of hoses. You suddenly feel a sharp pain at the base of a finger, as if something bit you, or as if you got poked by an exposed wire.
Now you have what looks like a fairly innocent puncture wound. It doesn’t hurt terribly, so you just “shake it off” and keep working. That decision may have just cost you a part of your hand.
What you have may be a hydraulic injection injury – generally regarded by doctors as an emergency requiring surgery. Damage to tissue may already be occurring. In time your hand will begin to throb and swell. If you delay treatment, enough damage may occur to require amputation of one or more fingers.
What happened?
Evidence indicates that hydraulic injection injuries are rare, but their severity demands that they be given attention. A Fluid Power Safety Institute (FPSI) study found that 99 percent of people who service, repair and troubleshoot hydraulic systems “have been subjected to the exact dynamics that trigger a high-pressure injection injury.”
But apparently in most cases it happens that the stream is aimed away from the person or is being deflected, so that it does not harm.
People at risk of these injuries could include you and your employees, if you work on your own equipment. How do these injuries happen? You know that hydraulic systems operate under high pressure. Fluid escaping from a source such as a pinhole leak in a hydraulic line can act like a “liquid bullet,” penetrating deep into tissue.
The fluid does damage on the way in, but that is only the beginning. Many fluids are caustic and quickly kill more tissue. The fluid then migrates through the fingers, hand and wrist, doing still more damage. Infections from bacteria in dead tissue often occur. Further, having been injected under pressure, the fluid can cause pressure buildup within “compartments” of the hand, damaging tendons, blood vessels, muscles and nerves.
Doctors generally consider taking these injuries straight to the operating room for surgery to relieve the pressure, remove the injected fluid, and trim away dead tissue. More surgeries may be needed a day or two later to re-examine for foreign matter or more tissue damage.
The injury’s severity depends on what kind of material was injected, how much of it, where it struck, and how soon the person gets medical attention. One problem with treatment is that doctors in a medical office or emergency room may misdiagnose the injury and send the person home with antibiotics or painkillers, or simply with instructions to keep the wound clean and rest.
Hard to detect
A scary aspect of these injuries is that the fluid can strike under such pressure that even heavy-duty work gloves provide little or no defense. The best protection is to keep hands and arms completely away from possible sources of fluid leaks.
When working on hydraulic systems, mechanics often run their hands over lines suspected of leaking, unknowingly putting themselves at risk. In other cases, they try to open or tighten lines, not realizing that pressure is still stored inside the system. Opening a line can cause a high-pressure release of fluid. Similarly, overtightening a fitting can lead to a split or crack through which fluid can escape.
Even when equipment is shut down, the FPSI says, hydraulic systems can retain pockets of high pressure. This can happen even after the pumps are shut off and the control levers are cycled to dissipate residual pressure.
Taking precautions
Leaks can be so small that they are not easily visible; in some cases all that shows is the fluid that accumulates on the ground or on a machine part. In addition, the source of a leak may be hidden within a hose bundle or behind other machine components. A technician who moves components while searching for a leak may actually end up aiming the high-pressure fluid stream at himself.
Experts say technicians should never use their hands to look for leaks. If necessary, they can place an object like a piece of cardboard, wood or steel in the path of a suspected leak. They should also use similar objects, rather than their hands, to move hoses or other obstacles.
The FPSI recommends following best practices for investigating fluid leaks. They include wearing personal protective equipment (PPE) that includes safety glasses and a full-face shield, de-energizing all hydraulic system zones that could store energy, and making sure everything is de-energized. Once that is done, a technician can run gloved hands over hoses searching for possible leaks and can safely loosen connectors.
Finding out more
In the event someone sustains a suspected injection injury, the person should be taken to a hospital emergency room or trauma center. Ideally, ice or a cold pack should be applied to the site to suppress swelling. It is helpful to show caregivers the name of the substance injected and the approximate pressure at which the injury occurred.
To advance the cause of properly treating these wounds, the FPSI offers a 15-minute DVD program, “The Lethal Strike: Procedures for Properly Managing Injection Injuries.” It covers what to do if someone suffers such an injury, what NOT to do, how to make sure the person gets proper medical treatment, and the responsibilities of everyone involved: the victim, the supervisor, the company owner or safety director, medical first responders, and physicians.
Bonus features include interviews with a hand surgeon and a medical director. You can watch a preview at www.fluidpowersafety.com/dvdintro.html.
