High-Pressure Hand Injury


Background

High-pressure injection injuries occur when a high-pressure injection device such as a paint or grease gun injects into the operator. Commonly, this injury occurs in the dominant hand and the index finger of the operator. [1However, cases involving the arms, feet, abdomen, and even cervical spine have been reported. [23Often, the injury may initially appear insignificant or benign. Future disability may be hidden behind a small, punctuate sore on the finger. [45 The clinical effects of the high-pressure injection injury depend upon a number of variables, including the pressures involved, chemical toxicity, and the quantity of material injected and its temperature. [6]

A high-pressure injection injury should be considered a surgical emergency. Immediate decompression and thorough cleansing of the offending material from the tissue is required to preserve optimal function.

Pathophysiology

Acute injury is caused by introduction of a foreign material, under high pressure between 2,000 and 10,000 psi, into the poorly distensible digital or palmar tissues. The pathophysiology involves direct trauma that may result in local tissue damage, acute and chronic inflammation, and foreign body granuloma formation. Damage results from the impact, ischemia due to vascular compression, chemical inflammation, and secondary infection. Highly viscous substances (eg, grease) require higher injection pressures than paint or solvents.

Hydrocarbon-based substances such as fuel, paint thinners, and organic solvents lead to the most severe inflammatory response with a high incidence of subsequent amputation. [7Grease- and oil-based compounds may lead to oleogranulomas with chronic fistula formation, scarring, and eventual loss of digit function.

Air and water injections also occur and are generally thought to be less serious because there is less resultant inflammation.

Epidemiology

Overall incidence of amputation approaches 48%. [8Morbidity is dependent to a large degree upon the material injected. Paint solvents appear to cause the greatest damage and result in amputation in 60-80% of the cases. Grease, the more common injectant, causes a less severe inflammatory response. Amputation is necessary in about 25% of these patients. [9]

These injuries are rare in women. High-pressure hand injuries usually occur in young men while working, most often to their nondominant index finger. The average age at time of injury in one large review was 35 years (range, 16-65 y). These injuries occurred to the nondominant hand 76% of the time.



History

The injection typically occurs to the fingertip when the operator is trying to wipe clear a blocked nozzle or to the palm when the operator is attempting to steady the gun with a free hand during the testing or operation of equipment. [1011]

The left hand (usually nondominant) is involved in about two thirds of cases.

The most common site of injury is the index finger.

The palm and long finger are the next most frequently injured.

Physical

The innocuous appearance of the wound may hide the severity of the injury. [128]

With time, edema and intense pain develop and the digit may appear erythematous or cold.

Causes

Most injuries have resulted from grease guns, paint sprayers, or diesel fuel injectors. The cause of injury in one case report was from a high-pressure paint gun. 



Laboratory Studies

Routine laboratory evaluation is unlikely to add useful information to the diagnosis of patients with high-pressure injection injuries. Diagnosis is clinical and based largely on patient history. However, secondary to the surgical nature of these injuries, routine preoperative evaluation may be initiated in the emergency department. Laboratory tests may include complete blood cell (CBC) count, electrolyte values and renal function, cardiography, and chest radiography.

Imaging Studies

Radiographs may facilitate the surgical strategy by localizing subcutaneous air, debris, or unanticipated fractures.


Approach Considerations

Initial treatment of high-pressure injection injury includes tetanus prophylaxis, broad-spectrum antibiotics, and consultation with a hand surgeon. Injections with air, gas, or small amounts of veterinary vaccines can usually be managed with observation and serial examinations if there is no concern about compartment syndrome. Injections with other liquid materials may require emergent surgical débridement, with the best results when the injury is treated within 6 hours. Wide surgical irrigation and debridement of necrotic tissues should be performed under general or regional anesthesia. Organic and caustic materials are associated with a higher amputation rate, and decreasing the time from injury to surgery improves the prognosis.

[14]

Emergency Department Care

Emergency department care for high-pressure hand injuries includes the following:

  • Obtain radiographs.

  • Prescribe broad-spectrum prophylactic antibiotics.

  • Update tetanus and administer parenteral analgesics.

  • Splint the extremity and keep it elevated.

  • Several authors report that steroids may be beneficial in selected cases, especially when an intense inflammatory response develops or treatment is delayed.

Consultations

Emergent consultation with an experienced hand surgeon is required. Prompt surgical debridement optimizes tissue salvage.



Medication Summary

The goal of therapy is to prevent infections. Prophylactic broad-spectrum antibiotics are indicated.

Antibiotics

Class Summary

Therapy must cover all likely pathogens in the context of the clinical setting.

Cefazolin (Ancef, Kefzol, Zolicef)

DOC; first-generation semisynthetic cephalosporin which, by binding to one or more penicillin-binding proteins, arrests bacterial cell wall synthesis and inhibits bacterial growth. Primarily active against skin flora, including Staphylococcus aureus.

Trimethoprim/sulfamethoxazole (Bactrim, Bactrim DS)

Inhibits bacterial synthesis of dihydrofolic acid by competing with para-aminobenzoic acid, inhibiting folic acid synthesis and thus bacterial growth. Antibacterial activity of TMP-SMZ includes common urinary tract pathogens except Pseudomonas aeruginosa.

Clindamycin (Cleocin)

Lincosamide useful as treatment against serious skin and soft-tissue infections caused by most staphylococci strains. Also effective against aerobic and anaerobic streptococci, except enterococci.

Tetracycline (Sumycin)

Treats susceptible bacterial infections of both gram-positive and gram-negative organisms, as well as infections caused by Mycoplasma, Chlamydia, and Rickettsia species. Inhibits bacterial protein synthesis by binding with 30S and possibly 50S ribosomal subunit(s) of susceptible bacteria.

Amoxicillin (Amoxil, Biomox, Trimox)

Interferes with synthesis of cell wall mucopeptide during active multiplication, resulting in bactericidal activity against susceptible bacteria.


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