Summary High-Pressure Injection Injuries are a traumatic condition characterized by extensive soft tissue damage associated with a benign high-pressure entry wound. Diagnosis requires obtaining a careful history and inspection of the digit involved. Treatment involves emergent surgical debridement. Epidemiology Incidence relatively rare, 1 in 600 hand traumas Demographics most common in young male laborers in industry using paint, automotive grease, solvents and diesel oil Anatomic location the non-dominant index finger is the most commonly affected digit >50% Etiology Pathophysiology mechanism of injury injection force delievered from 3,000 to 10,000 PSI and up to 400 MPH 100 PSI is enough force to break the skin pathophysiology 4 main components initial injury chemical irritation inflammation secondary infection pathoanatomy leads to dissection along planes of least resistance (along neurovascular bundles) vascular occlusion may lead to local soft tissue necrosis Presentation History important to document duration since event time to physician evaluation averages nearly 9 hours material injected Symptoms minimal or no pain at injection site pain and paresthesias eventually occur Physical exam inspection entry wound often benign looking only 1 in 4 initially present to ED eventually finger becomes bloated, edematous, tense, pale, and cold Imaging Radiographs may be useful to detect spread of radio-opaque dyes or paint Diagnosis Clinical diagnosis is made with careful history and physical examination Treatment Nonoperative tetanus prophylaxis, parenteral antibiotics, limb elevation, early mobilization, monitoring for compartment syndrome indications for injection of air, water, or chicken vaccine outcomes 50% of injuries treated nonoperatively will ultimately require an operation delayed surgical management associated with higher reoperation rates and postoperative complications Operative irrigation & debridement, foreign body removal and broad-spectrum antibiotics indications most cases require immediate surgical debridement outcomes higher rates of amputation are seen when surgery is delayed greater than 10 hours after injury 48% of finger injuries require amputation Technique Tetanus prophylaxis, parenteral antibiotics, limb elevation, early mobilization, monitoring for compartment syndrome considerations tetanus prophylaxis parenteral antibiotics gram-negative and gram-positive coverage limb elevation early mobilization pain control avoid digital blocks and ice to prevent decreased perfusion monitor for compartment syndrome Irrigation & debridement, foreign body removal and broad-spectrum antibiotics approach Bruner palmar digital incisions midaxial incision full exposure to zone of injury technique wide debridemeent of all involved tissues decompression of tissue compartments exploration and incision of tendon sheaths removal of all injected material saline irrigation repeat I&D at 24 to 72-hours complications postoperative infection 42% have positive cultures, most polymicrobial Complications Amputation amputation rates approach 50% with oil-based paint injection injuries Infection delayed treatment increases risk of postoperative infection necrotic tissue is a good culture medium for bacterial growth might be lower with organic solvent injections as they do not support bacterial growth Prognosis Up to 50% amputation rate for organic solvents (paint, paint thinner, diesel fuel, jet fuel, oil) Prognostic variables time from injury to treatment force of injection volume injected composition of material grease, latex, chloroflourocarbon & water based paints are less destructive industrial solvents & oil based paints cause more soft tissue necrosis