Thursday, June 5, 2008

High Pressure Injection Hand Injuries

Thankfully high-pressure injection injuries to the hand are uncommon because they have the potential to cause devastating consequences. To complicate things, these injuries often look innocuous with their initial presentation. Despite this innocuous looking injury, these accidents should be treated as limb-threatening injuries and immediately referred to a hand surgeon. (photo credit)

The three most common devices responsible for these injuries are:

1) grease guns -- A force of 100 to 200 psi (pounds per square inch) is generated by air compressors to propel the grease through the lubricating mechanism. The actual force is amplified by a pump and a reducing nozzle, so that a pressure of 5000 to 10,000 psi is generated.

2) spray guns -- A hydraulic pump forces paint through the spray gun at pressures up to 5000 psi.

3) diesel fuel injectors -- Pressures from 2000 to 6000 psi

The most commonly injected substances are automotive grease, diesel oil, paint, and varnish. Other substances reported include paint thinners, oil, molding plastic, cement, wax, air with rust, water with sand, and sealers (ref 6). There are reported injuries due to the solvents (ref 4) in the garment dry cleaning industry (isoparaffinic hydrocarbons, methoxypropanol, and dichlorofluoroethane) and also with Freon. Typically, paint and paint thinner injuries have much worse outcomes than grease gun injuries.

Injuries occur most often in men. The left hand (usually the non-dominant) is involved in nearly 2/3's of the cases. The most commonly injured site is the index finger, followed by the palm and the long finger. Direct contact with the skin is not necessary for injury. The jet may penetrate through gloves and other protective garments.

Mason and Queen in 1941 divided the clinical findings into three states:

Acute --

  • The immediate symptoms result from the injection of the foreign material are swelling, numbness, and vascular insufficiency.
  • This distention of the tissues may cause a pressure buildup that exceeds hydrostatic pressure, limiting tissue perfusion similar to that in compartment syndrome.
  • The chemical injury caused by the substance itself may result in tissue destruction and an inflammatory reaction (which leads to more swelling, which may further compromise the tissue perfusion)
  • Infection may occur in the necrotic tissue or from contamination from the substance injected.
  • Initially, the patient may complain only of mild pain and may even continue working, leading to a delay of care. The injured area may at first seem inconspicuous, presenting as a small pinprick, and caregivers who may not be familiar with this injury may regard it as insignificant. The finger eventually becomes painful, numb, bloated, edematous, tense, pale, and cold.
  • Radiographs may help assess the extent of the spread of the injected material, which may present as air in the soft tissue, or as radiopaque material in other cases.

Intermediate

  • Oleomas often develop following the acute phase. These are nodular "tumors" that develop as a result of a foreign body reaction to the injected material.
  • Oleomas may remain unchanged for years, but fibrosis often occurs with them, leading to loss of function. Because of this, oleomas should be excised completely along with any fibrosis associated with them.

Late

  • Skin overlying the untreated oleoma may breakdown. This may lead to ulcer and draining sinus formation.
  • The skin becomes thick and pitted.
  • The ulcers and draining sinuses may become infected.
  • Development of squamous epithelioma in the sinuses have been reported.

The following guidelines are suggested for optimal treatment:

1. Early medical evaluation, including radiographic studies.

2. Prompt surgical consultation. Patients treated properly within 10 hours of injury had much better outcomes than those treated in a delayed fashion.

3. Administration of tetanus prophylaxis and intravenous antibiotics.

4. Elevation and splinting before and after surgical exploration. Do not use cooling packs to control edema because their use may further compromise tissue perfusion.

5. Surgical exploration using general anesthesia or axillary block. Digital and local blocks may contribute to tissue edema and are associated with worse outcomes.

6. Use of an extremity tourniquet to establish a bloodless operative field after exsanguinating the arm by elevation. Esmarch bandage exsanguination may cause further spread of the injected toxins into tissue planes or compartments.

7. Wide surgical exploration, including decompression of tissue compartments, debridement of nonviable tissue, and high-volume saline irrigation. Particular attention should be directed toward fluid tracking around neurovascular bundles. Flexor tendon sheaths are less likely to be involved. (photo credit, at 48 hrs post injury)

8. Wound cultures when appropriate to direct antibiotic therapy.

9. Consider leaving the wound open, with a planned second look operative irrigation and debridement.

10. Consider early amputation of a cool or poorly perfused digit.

11. If edema is significant, consider administering 100 mg of hydrocortisone intravenously every 6 hours until improvement is observed. Change to 25 mg of oral prednisone daily and taper over 3 to 5 days. Restart hydrocortisone if edema, erythema, or pain worsens. [Controversial.]

12. Frequent postoperative reassessment and return to the operating room if indicated.

13. Early postoperative hand therapy to maximize functional outcome.

Prevention of these injuries is the best.

(photo credit, same hand as second photo)

REFERENCES

1. High-Pressure Injection Injuries of the Hand; Plastic & Reconstructive Surgery. 45(3):221-226, March 1970; Ramos, Hernando M.D.; Posch, Joseph L. M.D.; Lie, Kim K. M.D.

2. Conservative management of a high pressure injection injury to the hand; Plastic & Reconstructive Surgery. 72(5):742, November 1983; Kelleher, John C.; Kendrick, R. W; Colville, J.

3. UPPER EXTREMITY: Emergency management of high pressure injection injuries of the hand; Plastic & Reconstructive Surgery. 83(2):403, February 1989; El, Helaly M.; Beheri, Gamal E.

4. High-Pressure Hand Injection Injuries Caused by Dry Cleaning Solvents: Case Reports, Review of the Literature, and Treatment Guidelines; Plastic & Reconstructive Surgery. 111(1):174-177, January 2003; Gutowski, Karol A. M.D.; Chu, Jason M.D.; Choi, Mihye M.D.; Friedman, David W. M.D.

5. Long-Term Follow-Up of High-Pressure Injection Injuries to the Hand; Plastic & Reconstructive Surgery. 117(1):186-189, January 2006; Wieder, Anat M.D.; Lapid, Oren M.D.; Plakht, Ygal M.Med.Sc.; Sagi, Amiram M.D.

6. High Pressure Injection Injuries; Hand Clinics 2 (3), 1986: pp 547-552; B Thomas Harter Jr MD and Kathleen C Harter MD

7. Grease gun injuries to the hand: Pathology and Treatment of Injuries (oleomas) following the injection of grease under high pressure.; Quarterly Bulleting of Northwestern Medical School, 15:122, 1941; Mason, M. L. and Queen, F. B.

8. High-Pressure Injection Injuries; eMedicine, Feb 19, 2008; Jugpal S Arneja MD and others

2 comments:

noble pig said...

Whoa, what a picture!

Dean said...

I think you just try to gross me out on purpose. :)

Actually, a very interesting and eye-opening post. I have had occasion to use the mentioned high-pressure devices in the past. I will be much more careful in the future. Thanks.