HIGH PRESSURE INJECTION INJURIES | Hand Surgery Resource

Introduction

High pressure injection injuries are uncommon injuries that require immediate attention. Unfortunately, injured individuals can often present late due to the benign appearance of the initial wound. A thorough history regarding timing of injury, substance injected, if the injury was work related, and what safety protocols were employed is key. Extensive surgical debridement is often warranted, with a select few cases being amenable to close observation. Patient education regarding the potential serious nature of these injuries is important.

Intravenous extravasation injuries may also be encountered. Similar principals apply when evaluating these injuries. Treatment is based on whether the extravasated material is an irritant or vesicant. Common irritants, such as saline, may be treated more conservatively, while certain vesicants, such as chemotherapy agents, may require a more specialized treatment.

Similarly, accidental injection of an EpiPen into the digit or hand may be encountered. Although there is concern of low-dose epinephrine causing tissue necrosis of the effected digit, there are currently no documented cases of this occurring⁹. These injuries are often treated with close observation and the occasional use of phentolamine.

Pathophysiology

High pressure injection injuries occur when an object is injected at high pressures into the skin. 100 PSI is often cited as the amount of force necessary to break the skin, although there is no direct study proving this¹. The injected material travels through the path of least resistance, often along neurovascular structures, until hitting a denser object (flexor tendons, pulleys, metacarpal bones, ect.). Injury is thought to be caused from the initial force, distention and compression of local structures, and chemical irritation. Tissue necrosis and vascular thrombosis can be seen as early as 1.5 hours after injection in histology studies⁴.

Related Anatomy

Skin
Flexor tendons
Flexor tendon sheath
Digital nerve
Digital artery

Incidence and Related Conditions

1 in 600 hand traumas
92-99% Male
50-78% Non dominant index finger¹
Extravasation injuries
- Irritant materials (saline, radiographic contrast)
- Vesicant materials (Chemotherapy agents, TPN)

Important Questions To Ask These Patients

Type of material injected
Time of injection
If the injury was work related
- What safety protocols were employed

Differential Diagnosis

High pressure injection injury
- Work related
- Self harm
Extravasation injury
Flexor tenosynovitis

Clinical Presentation Photos and Related Diagrams

INJECTION INJURY

Injection injury (arrow) 36 hours after accident with power washer. Note finger swelling.
Left index grease gun injection injury 36 hours after accident.
Epinephrine injections save lives but accidental injection into a finger can potentially cause tissue damage.
Neglected subcutaneous chemotherapy extravasation with secondary cellulitis.

Symptoms

Early complain of a seemingly minor injury that is painless

Later present skin edema, necrosis and pallor

Later severe pain

Can mimic compartment syndrome of the digits

Typical History

A typical patient is a 40-year-old male laborer presenting after accidental injury of his non-dominant hand at work. The patient was using a high-pressure paint gun when his hand slipped and he accidentally injected his non-dominant index finger. The initial wound appeared benign, and so the patient did not seek immediate treatment. An hour later, the patient began to experience extreme pain, swelling, and erythema of the digit and promptly came to the emergency department.

Positive Tests, Exams or Signs

Work-up Options

Treatment Options

Treatment Goals

Be aware, seemingly innocuous wound can cause significant tissue damage and necrosis
Maintain hand function
Preserve grip and pinch strength
Early I&D to avoid compartment syndrome and/or infection

Conservative

Requires accurate knowledge of material injected, pressure of injection, and time since injection
Close observation, tetanus prophylaxis, and broad-spectrum antibiotics may be considered for injection of animal vaccinations and certain keyboard cleaners^6,8.
Extravasation of irritant materials may be treated with strict elevation and close monitored for worsening of symptoms or signs of compartment syndrome⁵. Any patient with worsening symptoms would be reevaluated and more often than not need surgical treatment.

Operative

Operative intervention should consist of a wide debridement of all tissues, decompression of any violated compartments, and potential exploration of tendon sheaths. The use of loupes or an operative microscope should be considered to fully evaluate neurovascular contamination
During debridement, extra care must be used to protect the nerves and vessels
Negative pressure wound therapy and repeat irrigation and debridement should be strongly considered
Irrigating the wound at the end of debridement to dilute any remaining materials and returning to the operating room the following day can potentially reduce complications of incomplete debridement³
Surgery should be performed as soon as possible for injection of most substances and vesicant extravasation materials^1,5,7
Gault Flush-out Technique⁵
- Inject 1% lidocaine subcutaneously around area of extravasation
- Inject 1,500 U of hyaluronidase subcutaneously into effected area
- Create 4 stab incisions around the periphery of the lesion
- Irrigate each incision with a saline filled syringe
  - A total of 500 mL should be used
- Cover wound with dry, sterile dressing and monitor daily
- Commonly used in pediatric extravasation injuries¹⁰
  - Lack of high-quality studies comparing the effectiveness of the Gault technique to other treatments (ex. observation, surgical I&D)

Type of injury	Signs	Treatment
Water soluble materials (Saline, water-based acrylic paint), Air	Small entry wound. Erythema and swelling.	Close observation, tetanus prophylaxis, antibiotics, elevation. Monitor for compartment syndrome, especially if large volumes were injected
Animal vaccines (chicken, fish)	Small entry wound. Erythema and swelling.	If no oil emulsion adjuvant Close monitoring, tetanus prophylaxis, antibiotics, elevation. If Oil adjuvant (ex. Mineral oil) Immediate surgical debridement, broad spectrum antibiotics, tetanus prophylaxis
EpiPen Injection Irritant extravasation (Saline, radiographic contrast)	Cool, pale digit, paresthesia Swelling, +/- erythema. Moderate tenderness	Close monitoring, warm compress, +/- phentolamine, +/- Nitropaste Close observation, elevation.
Vesicant extravasation (TPN, arginine, phenytoin)	Swelling, erythema, blistering. Severe tenderness	Gault flush-out technique, +/- surgical debridement.
Oil based materials, industrial solvents (paint thinner, hydraulic fluid), insecticides	Small entry wound. Bloated, tense, pale extremity with late presentation. +/-tissue necrosis.	Immediate surgical debridement, foreign body removal, broad spectrum antibiotics, repeat debridement, delayed closure

Chemotherapy Extravasation Treatment
Extravasate	Treatment
Plant alkaloids (Vinblastine/vincristine)	1-6 mL of 150 U/mL solution of hyaluronidase injected into area (1 mL of solution per mL of extravasate)
Antrhacyclines (Doxorubicin, Daunorubicin)	IV dexrazoxane into the opposite extremity (1,000 within 6 hours of the event, then 1,00 units on day 2, 500 U on day 3)
Mechlorethamine	Inject a mixture of 4mL of 10% sodium thiosulfate and 6 mL locally (2mL for each mg of extravasate)

Complications

Non operative management of oils and other cytotoxic materials can lead to an amputation rate of 88%¹
Stiff digit with significant loss of range of motion and pinch/grip strength is common even after early surgery

Outcomes

Amputation rates range from 16-38% with early debridement
A delay in debridement > 6 hours is associated with an amputation rate of up to 58%¹
Stiffness and hypersensitivity of hand is common after injury
- Hand therapy is essential to minimize these complications

Key Educational Points

Exam the patient’s extremity for potential entry and exit wounds
Full extent of injury is often not apparent until debridement
Consider obtaining serial X-ray’s to look for air in soft tissue and residual material after debridement³
Most injuries require immediate, formal operative debridement
Delay in surgical treatment increases morbidity and amputation rates
Organic solvents (paint thinner) and oil-based materials carry the highest amputation risk
Patient’s treated with Gault-flush out technique should be monitored daily. Formal irrigation and debridement should be done if there are any signs of compartment syndrome or skin necrosis

References

Pappou IP, Deal DN. High-pressure injection injuries. J Hand Surg Am. 2012;37(11):2404-7. PMID: 22999384.
Buchman MT. Upper extremity injection of household insecticide: a report of five cases. J Hand Surg Am. 2000;25(4):764-7. PMID: 10913221.
Barr ST, Wittenborn W, Nguyen D, Beatty E. High-pressure cement injection injury of the hand: a case report. J Hand Surg Am. 2002;27(2):347-9. PMID: 11901397.
Failla JM, Linden MD. The acute pathologic changes of paint-injection injury and correlation to surgical treatment: a report of two cases. J Hand Surg Am. 1997;22(1):156-9. PMID: 9018630.
Hannon MG, Lee SK. Extravasation injuries. J Hand Surg Am. 2011;36(12):2060-5. PMID: 22123049.
Kovachevich R, Kaplan FT. Animal injection injuries. J Hand Surg Am. 2012;37(11):2408-11. PMID: 22995697.
Devulapalli C, Han KD, Bello RJ, et al. Inadvertent Intra-Arterial Drug Injections in the Upper Extremity: Systematic Review. J Hand Surg Am. 2015;40(11):2262-2268.e5. PMID: 26409581.
Craig EV. A new high-pressure injection injury of the hand. J Hand Surg Am. 1984;9(2):240-2. PMID: 6715833.
Fitzcharles-Bowe C, Denkler K, Lalonde D. Finger injection with high-dose (1:1,000) epinephrine: Does it cause finger necrosis and should it be treated?. Hand (N Y). 2007;2(1):5-11.
Little M, Dupré S, Wormald JCR, Gardiner M, Gale C, Jain A. Surgical intervention for pediatric infusion-related extravasation injury: a systematic review. BMJ Open. 2020;10(8):e034950. Published 2020 Aug 6.

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