High-pressure injection (HPI) injuries occur when substances are accidentally injected by industrial equipment with pressure high enough to break the skin. The injected substance causes extensive tissue damage and sometimes results in amputation.
High-pressure injection injuries are rare but have serious consequences, including loss of a limb.
The affected body part may not be able to function normally, muscles may become permanently stiff, and people may have chronic pain and abnormal sensations.
Prompt diagnosis and treatment are essential to prevent serious consequences.
To diagnose the injury, doctors ask detailed questions about the injury and take x-rays.
Treatment includes antibiotics and surgery.
High-pressure injection (HPI) injuries are usually work-related but occasionally occur in hobbyists or homeowners. Most HPI injuries occur in the nondominant hand of male workers in their 30s.
HPI injuries are rare, even though the use of high-pressure injection apparatus and activities are common in industry. Industrial fluids that may be injected include paints, air, solvents, gasoline, hydraulic fluid, grease, and water. HPI injuries have serious consequences, including loss of a limb.
Symptoms of High-Pressure Injection Injuries
An HPI injury makes a small puncture wound that is not clear cut. The pain and swelling around the wound are slight until hours later.
If fluid is injected into the limbs or hand, the affected muscles may swell so much that they cut off the blood supply, causing compartment syndrome, a serious disorder.
People may eventually lose function in the affected body part. Muscles may shorten and become permanently stiff (called contractures), causing joints to become permanently bent. Contractures limit range of motion.
People with an HPI injury may also have chronic pain, increased sensitivity to pain, and abnormal sensations, such as tingling or a pins-and-needles sensation. Bacterial infections may develop.
Diagnosis of High-Pressure Injection Injuries
A doctor's evaluation
X-rays
HPI injuries are considered an emergency, sometimes requiring immediate surgery. Prompt and correct diagnosis of an HPI injury is essential to prevent serious consequences. However, because the initial symptoms are sometimes slight, their severity is easy to underestimate.
To diagnose an HPI injury, doctors ask detailed questions:
When the puncture wound occurred
How the wound occurred
What equipment was being used
If available, what was the substance in the injector and the pressure of the injection tool
Doctors carefully document the injured body part. X-rays or other imaging tests (such as ultrasonography, CT, or MRI) are done to check for fractures and the injected substance. If the injected substance can be seen on imaging, the result can be used to determine how deep the injury is. Photographs of the injured body part may also be taken.
Prognosis of High-Pressure Injection Injuries
Two factors that determine the prognosis for people with an HPI injury are
The substance injected
Injection pressure
Paints and solvents (liquids that other substances dissolve in) cause the most severe injuries and result in the worst prognosis. Lower injection pressure usually results in less injury, and higher pressure usually results in more extensive injury.
Disability may be permanent.
When solvents are injected, as many as 50 to 80% of people with an HPI injury lose a limb (require amputation).
Treatment of High-Pressure Injection Injuries
Antibiotics given by vein (intravenously)
Prompt surgery
Doctors first gently clean the wound and loosely wrap the injured body part with a sterile dressing, The injured part is elevated.
People with an HPI injury are given antibiotics that treat many infections (broad-spectrum antibiotics) intravenously and, if needed, the tetanus vaccine. Pain relievers are given as needed.
Surgery to examine and evaluate all HPI injuries is done as soon as possible. Surgery is done in a operating room and requires general anesthesia. Surgery is best done by a knowledgeable surgeon experienced in treating HPI injuries. The surgeon removes dead tissue and as much of the injected substance as possible. The incision is usually left open (not stitched up) and allowed to heal, or the surgeon waits to stitch up the incision until later.
Amputation (of finger, toes, or limbs) may be required.
A splint may be applied to the affected limb to avoid stressing the wound so that the wound can heal more quickly.
Physical therapy and occupational therapy can help workers regain function. Sometimes a second operation is needed to improve the function of the limb.
