The Case:
A 42-year-old right hand dominant male with no known past medical history presents with pain in his right thumb. He works as a painter and was using an industrial paint sprayer when he injected a water-based paint into his right distal thumb pad. He states he had significant pain initially, but it quickly settled to a dull throbbing. He waited five days from the injury to visit his primary care doctor who instructed him to come directly to the ED. His vital signs are within normal limits. There is a small punctate wound on the volar surface of the distal right thumb that is mildly tender to palpation without surrounding erythema, swelling, or drainage. There is no tenderness more proximally. Compartments of the hand and forearm are soft and compressible. The digit is neurovascularly intact excluding an area of decreased sensation at the tip of the thumb. X-ray of the right hand and thumb are shown below.
This is a delayed presentation of a serious injury: high pressure injection injury. What are the most important prognostic features of the history and exam? How would you manage this in the ED? What would be your final disposition for this patient?
High Pressure Injection Injury:
Background
➢ 1/600 hand injuries with 1-4 cases presenting to trauma centers annually1
➢ Surgical emergency with amputation rate ~30%, and as high as 70%2,3
➢ Only 100 PSI of pressure required to break skin4
○ Industrial injectors can apply up to 10,000 PSI
➢ Most commonly an injury of the non-dominant hand
➢ Initial presentation can be misleadingly innocuous
Important Features of History
➢ Type of injected material and time since injury are the most important prognostic factors for amputation
○ Injection with diesel, paint thinner, oil, and paint carry the greatest risk
○ Treatment within 6 hours of injury has best prognosis
Fig 1: Relative risk of amputation based on injected fluid type from Hogan et al., 20032.
➢ Further document handedness, occupation, site of injury, and thorough review of systems to evaluate for potential complications
○ Complications as distant as pneumomediastinum following air injection of the hand have been reported5,6.
➢ PSI does not significantly influence the rate of amputation2,10
Pathophysiology:
➢ Phase 1: Direct mechanical impact that can tear ligaments, tendons, neurovascular structures, and cause osseous lesions
➢ Phase 2: Inflammatory sequela and chemical interactions of injected media with biologic substrates
○ Turpentine (paint thinners) and organic solvents dissolve lipids causing liquefactive necrosis
○ Oil-based paints are associated with inflammatory reactions
○ Grease and wax cause granulomatous inflammation and granulomas chronically
○ Air and water are absorbed and generally skip this phase
➢ Phase 3: Secondary infection
Important features of the Physical Exam
➢ Injury <6 hours may appear benign without pain or significant external soft tissue damage
➢ Injury greater than 6 hours, especially beyond 12, may show signs of necrosis, skin breakdown, limb ischemia, and/or signs of systemic toxicity
➢ General exam of hand:
○ What is the appearance of the skin?
○ What is the resting position of the hand
○ Where is there tenderness? Does it extend beyond injury?
○ Pain with short arcs? Passive and/or active ROM?
➢ Neurovascular exam is paramount
○ Evaluate radial/median/ulnar nerves
○ Assess capillary refill, radial and ulnar pulses
Work up:
➢ X-ray of hand and digit to evaluate spread of radio-opaque materials and osseous lesion
➢ Laboratory investigation not required for acute injury, but may be required if signs of systemic illness
○ Some authors advocate to track inflammatory markers7
Management
➢ Emergent orthopedic surgery consult
○ Surgical debridement required for majority
○ Non-operative therapy can be considered for low risk injections such as water or air
➢ Control pain but AVOID digital blocks due to risk of increasing pressure with extra volume
➢ Initiate broad spectrum antibiotics for gram positive and negative bacteria
➢ Splint and elevate limb
➢ Update tetanus
➢ All acute injuries should be admitted for observation at minimum
➢ Steroids can be considered in mild injury and should only be administered in conjunction with a specialist, though case reports do not support their routine use2
➢ Long-term complications can develop including tumor, granuloma, and loss of function10
A bit more on paint injections:
Determining what type of paint was injected, whether it is water based or otherwise, can greatly change prognosis. Oil based paints consist of a solvent, a pigment, and a transport vehicle or binder that facilitates adherence. The transport vehicles and binders can be unsaturated oils, drying oils, or a synthetic polymer, each of which can cause corrosion and damage to local tissues. In contrast, the vehicles and binders in water-based paints, also known as latex based paints, are made from acrylic latex, which is much less irritating to local tissue. Research suggests that injections with these chemicals, even with presentations delayed up to 24 hours after insult, has very good prognosis with no reported amputations9,10
Resolution of our case
Our patient presented six days after an injection with a water (latex) based paint. There were no signs of infection, compartment syndrome, tissue necrosis, or limb ischemia. X-rays showed radiopaque foreign bodies confined to the distal thumb without fracture. Orthopedics was consulted and recommended outpatient follow up in several days. We further determined that the risks associated with antibiotic treatment were greater than the questionable prophylaxis they may provide at this stage, and did not prescribe a course of PO antibiotic on discharge. The patient followed up in hand clinic where he underwent incision and drainage showing the subcutaneous tissue stained with white paint. He was copiously irrigated. The patient was contacted two weeks following his procedure and states he has minimal pain and no functional or sensory deficit.
Authored by Adam Roussas, MD, MBA, MSE
Works Cited
Verhoeven N, Hierner R. High-pressure injection injury of the hand: an often underestimated trauma: case report with study of the literature. Strategies Trauma Limb Reconstr. 2008 Apr;3(1):27-33. doi: 10.1007/s11751-008-0029-9. Epub 2008 Feb 2. PMID: 18427921; PMCID: PMC2291478.
Hogan CJ, Ruland RT. High-pressure injection injuries to the upper extremity: a review of the literature. J Orthop Trauma. 2006 Jul;20(7):503-11. doi: 10.1097/00005131-200608000-00010. PMID: 16891944.
Vitale E, Ledda C, Adani R, Lando M, Bracci M, Cannizzaro E, Tarallo L, Rapisarda V. Management of High-Pressure Injection Hand Injuries: A Multicentric, Retrospective, Observational Study. J Clin Med. 2019 Nov 16;8(11):2000. doi: 10.3390/jcm8112000. PMID: 31744068; PMCID: PMC6912633.
Dailiana HZ, Kotsaki D, Varitimidis S, Moka S, Bakarozi M, Oikonomou K, Malizos NK. Injection injuries: seemingly minor injuries with major consequences. Hippokratia. 2008 Jan;12(1):33-6. PMID: 18923762; PMCID: PMC2532970.
Joseph T, Rolando GG. High-Pressure Injection Injury to the Hand With Resulting Pneumomediastinum: A Case Report. The Journal of Emergency Medicine. 2022. ISSN 0736-4679. doi: 10.1016/j.jemermed.2022.05.017.
Temple CL, Richards RS, Dawson WB. Pneumomediastinum after injection injury to the hand. Ann Plast Surg. 2000 Jul;45(1):64-6.
Yıldıran G, Sütçü M, Akdağ O, Tosun Z. High-pressure injection injuries to the upper extremity and the review of the literature. Ulus Travma Acil Cerrahi Derg. 2020 Nov;26(6):899-904. English. doi: 10.14744/tjtes.2020.26751. PMID: 33107958.
Rosenwasser MP, Wei DH. High-pressure injection injuries to the hand. J Am Acad Orthop Surg. 2014 Jan;22(1):38-45. doi: 10.5435/JAAOS-22-01-38. PMID: 24382878.
Lozano-Calderón SA, Mudgal CS, Mudgal S, Ring D. Latex paint-gun injuries of the hand: are the outcomes better? Hand (N Y). 2008 Dec;3(4):340-5. doi: 10.1007/s11552-008-9110-6. Epub 2008 May 28. PMID: 18780017; PMCID: PMC2584224.
Eells AC, McRae M, Buntic RF, Boczar D, Oliver JD, Huayllani MT, Restrepo DJ, Sisti A, Forte AJ. High-pressure injection injury: a case report and systematic review. Case Reports Plast Surg Hand Surg. 2019 Dec 18;6(1):153-158. doi: 10.1080/23320885.2019.1654388. PMID: 32002465; PMCID: PMC6968540.