Emerg Radiol DOI 10.1007/s10140-014-1204-6
PICTORIAL ESSAY
High-pressure paint gun injury: clinical presentation and imaging findings Greg Peters & Thomas Learch & Eric White & Deborah Forrester
Received: 12 December 2013 / Accepted: 7 February 2014 # Am Soc Emergency Radiol 2014
Abstract High-pressure paint gun injuries are potentially devastating injuries that require emergent surgical incision and drainage. They result from erroneous equipment operation and accidental injection of a variety of substances at pressures high enough to breach the skin. The largely benign superficial appearance masks the extent of the underlying injury. In the absence of an appropriate history, the radiologist must recognize the characteristic radiographic findings and suggest the diagnosis to the clinician. Keywords Paint gun injuries . Phalanges . Radiography
Introduction High-pressure paint gun injuries are potentially devastating injuries that require emergent surgical incision and drainage. They result from erroneous equipment operation and accidental injection of a variety of substances at pressures high enough to breach the skin [1]. The largely benign superficial
appearance masks the extent of the underlying injury. In the absence of an appropriate history, the radiologist may have to suggest the diagnosis to the clinician. The first reported high-pressure injection injury was in 1925 during the repair of a diesel engine fuel injector [2]. Initial literature description of these injuries was in 1937. Despite a lengthy history of occurrence, many health care workers may be unfamiliar with these injuries and their potential consequences. High-pressure paint gun injuries are essentially rare for any one emergency department, accounting for one in 600 hand injuries [3]. Twenty-eight cases were documented within a 7year span at our urban county hospital. Nearly all reported cases involved male occupational injuries and injury to the nondominant second or third digit [4]. The number of unreported cases is difficult to estimate and may be quite large. Prospective or population-based studies are not available at this time [1].
Pathophysiology and clinical findings G. Peters (*) 37610 College Drive #201, Palm Desert, CA 92211, USA e-mail: [email protected] T. Learch S. Mark Taper Foundation Imaging Center, Cedars-Sinai Medical Center, 8700 Beverly Blvd., Suite M-335, Los Angeles, CA 90048, USA e-mail: [email protected] E. White : D. Forrester USC Radiology Department, Keck School of Medicine, 1500 San Pablo Street, Los Angeles, CA 90033, USA E. White e-mail: [email protected] D. Forrester e-mail: [email protected]
High-pressure paint guns are readily available to the average consumer for do-it-yourself projects and painting (Fig. 1). They are used commercially for painting as well as greasing, cleaning, lubricating, and mass inoculation of animals. A pressure of 100 lbs per square inch (psi) is sufficient to breach the skin surface, and these machines are capable of producing pressures between 2,000 and 12,000 psi [4], much of which results from pressure increases created as material is ejected through apertures between 0.18 and 1.0 mm wide [5] (Fig. 2). These extreme pressures can propel injected material through the skin surface and subcutaneous tissues to the bone or along fascial planes, tendon sheaths, and neurovascular bundles. The most commonly injected materials are paint and grease. Other commonly injected substances include paint solvents
Emerg Radiol
Fig. 1 High-pressure paint gun
and fuel oil, while air, water, cement, and animal vaccines have also been reported [1]. Injection injuries most commonly occur due to inexperience or insufficient training and result from attempts at unclogging a gun nozzle. The injury often occurs in young male workers either painting for seasonal work or as day laborers. However, the authors have encountered a professional painter who was injured and was fully aware of the potential dangers of operating this equipment. The typical scenario occurs when the gun aperture clogs. The operator typically holds the gun with the dominant hand and uses the second or third finger of the nondominant hand to clear debris from the nozzle and aperture. The gun tip need not to be in contact with the skin surface to penetrate it, and injury may even occur through a barrier such as a cloth used to clean the nozzle [6]. Accidental discharge has also been reported while reaching
Fig. 2 Paint gun aperture (thin white arrow) and surrounding tip guard (thick white arrow)
for a dropped gun [6]. Even when turned off, these highpressure systems remain a danger until the pressure has dissipated. Complete safety manuals are multilingual, but quick start guides are not. In the authors’ experience, sales personnel have limited knowledge about both operation and safety. Clinical presentation is highly dependent on both the type of injectate as well as time to presentation. The injection pressure, volume, and anatomical level also contribute to injury severity [2]. The wound begins as an innocuous pinpoint entry site with mild symptoms of swelling, allowing for underestimation of its potential for debilitation by both patients and physicians [4] (Fig. 3). Even small amounts of material can lead to compartment syndrome, poor perfusion, and closed space infections resulting in tissue necrosis [2]. Direct tissue damage results from the high-velocity injury, and spread of the injectate follows the path of least resistance. Contaminant most easily spreads locally and from distal to proximal along a digit within tissue planes. Anatomic studies show variation of spread based on the tissues encountered [2]. Deflection off the more superficial fibrous flexor tendon sheaths results in local spread. This usually occurs when injectate encounters the rigid fibrous sheath overlying the phalanges also known as the A (annular) pulley. Injections occurring at the level of either the distal interphalangeal or proximal interphalangeal joints often encounter the more
Fig. 3 A 28-year-old male with pinpoint penetration injury to the volar aspect of the second digit at the distal interphalangeal joint level (arrow)
Emerg Radiol
flexible C (cruciform) pulley and penetrate through to the synovial tendon sheath (Fig. 4). When contaminant reaches the deeper synovial tendon sheaths, it may spread as far as the metacarpophalangeal joint level in the second, third, and fourth digits. If injected into either the first or fifth digit, it may follow the tendon sheaths retrograde to communications with either the radial or ulnar bursae within the hand [7].
Radiographic findings Radiography is the imaging test of choice and does well to identify radiopaque materials (Fig. 5) but may underestimate the extent of dispersion of foreign material [8]. Both latex and the less common oil-based paints are easily seen. Grease may be radiolucent or radiopaque depending on its lead content.
Differential diagnosis With an appropriate history, the diagnosis is easily made. In the absence of an appropriate history, one might consider calcinosis cutis or soft tissue calcifications in the setting of connective tissue disease such as scleroderma or dermatomyositis (Fig. 6). These patients are however more often female and older in age with involvement of multiple fingers. If the injectate is gas, water, or even grease, radiopaque material will be absent, but soft tissue gas will be present with or without an obvious soft tissue laceration or soft tissue swelling.
Fig. 5 a, b A 39-year-old male with paint gun injection injury to the third digit (arrows). The surgeon found an intact flexor tendon sheath, though it is difficult to tell from the radiographs that there was no spread within the tendon sheath
broad-spectrum antibiotics, limb elevation, and referral to orthopedics for immediate debridement [2]. Local anesthetics, including digital blocks, are contraindicated as they may raise compartment pressures [2, 9]. All nonviable tissue should be
Treatment and follow-up Prompt recognition with early surgical debridement and decompression are mandatory [2]. Treatment in the emergency department includes tetanus prophylaxis, administration of
Fig. 4 Anatomic sketch of the digit flexor tendons and associated tendon pulleys. FDP flexor digitorum profundus; FDS flexor digitorum superficialis; PIP proximal interphalangeal joint; DIP distal interphalangeal joint
Fig. 6 A 46-year-old female. A case for comparison to Fig. 4, with calcinosis cutis in a patient with scleroderma (arrows)
Emerg Radiol
excised, while all viable tissue should be copiously irrigated, and wounds should be left open for possible further debridement [9]. It is not unusual for foreign material to remain, especially foreign material that is adherent to neurovascular bundles [2]. An analysis of 435 cases occurring between 1966 and 2003 showed that steroid administration did not impact the rate of amputation or incidence of infection [10]. The overall rate of amputation was 30 % and particularly related to the location of injury and type of material injected [10]. The amputation risk associated with latex paint was 5 % versus 60 % with oilbased paints [10]. Optimal time for wide surgical debridement was within 6 h of injury [2, 10, 11], although it is difficult to establish a benchmark. Other studies have documented an amputation rate of approximately 40 % when surgery is performed within 6 h and an amputation rate of 57 % when surgery is delayed beyond 6 h [3, 10–12]. The amputation risk is as high as 87 % without treatment or if treatment is further delayed. Due to the initial benign injury appearance, patients will often delay their initial presentation. An accurate and timely diagnosis is crucial to outcomes. In the absence of amputation, the potential for long-term debilitation is significant. A study of 23 patients followed for an average of 8.5 years after initial injury recorded several complaints affecting activities of daily living and reintegration into the workforce. Neurologic impairments such as cold intolerance, hypersensitivity, paresthesias, and constant pain were the most common. Patients had mild reduction of range of motion and grip strength as well [2]. The permanent partial impairment varies from 4 % for those treated within 6 h versus 17 % for those treated after 6 h [2]. Despite chronic complications of high-pressure injection injury, up to 92 % of workers have returned to their prior jobs [13].
Conclusion High-pressure paint gun injuries are rare but potentially devastating injuries despite the initial benign presentation. They are characterized by a small, punctate skin lesion with potentially severe subcutaneous tissue damage [2]. Radiographs have typical appearances with a limited differential diagnosis. The radiologist should be familiar with the possibility of occult spread along the digit and even into the hand, and alert the often unsuspecting or less experienced surgeon [14]. An immediate wide surgical exploration, debridement, and decompression must be carried out with attempts to remove all foreign material and necrotic tissue [13, 15]. Time to surgical treatment (less than 6 h) and chemical composition of the
injected material are the only factors which are consistently associated with prognosis [3, 6, 10–12]. High-pressure paint guns are potentially very dangerous. Workers, however, continue to use these devices with inadequate training and dangerous technique leading to the ongoing occurrence of injuries. Occupational injury prevention campaigns for communities at risk may decrease the incidence of injury. Given the inconsistent clinical experiences among providers with these types of injuries and the patients’ tendency to underestimate the injury, the radiologist may be required to make the diagnosis. Conflict of interest The authors declare that they have no conflict of interest.
References 1. Dailiana HZ, Kotsaki D, Varitimidis S, Moka S, Bakarozi M, Oikonomou K, Malizos NK (2008) Injection injuries: seemingly minor injuries with major consequences. Hippokratia 12:33–36 2. Harter BT, Harter KC (1986) High pressure injection injuries. Hand Clin 2:547–552 3. Schoo MJ, Scott FA, Boswick JA Jr (1980) High-pressure injection injuries of the hand. J Trauma 20:229–238 4. Hart RG, Smith GD, Haq A (2006) Prevention of high-pressure injection injuries to the hand. Am J Emerg Med 24:73–76 5. Waters WR, Penn I, Ross HM (1967) Airless paint gun injuries of the hand: a clinical and experimental study. Plast Reconstr Surg 39:613– 618 6. Gillespie CA, Rodeheaver GT, Smith S, Edgerton MT, Edlich RF (1974) Airless paint gun injuries: definition and management. Am J Surg 128:383–391 7. Kaufman HD (1968) The anatomy of experimentally produced high pressure injection injuries of the hand. Br J Surg 55:340–344 8. O’Reilly RJ, Blatt G (1975) Accidental high-pressure injection gun injuries of the hand. J Trauma 15:24–31 9. Gonzalez R, Kasdan ML (2006) High pressure injection injuries of the hand. Clin Occup Environ Med 5:407–411 10. Hogan CJ, Ruland RT (2006) High pressure injection injuries to the upper extremity: a review of the literature. J Orthop Trauma 20:503– 511 11. Schnall SB, Mirzayan R (1999) High pressure injection injuries of the hand. Hand Clin 15:245–248 12. Stark HH, Ashworth CR, Boyes JH (1967) Paint-gun injuries of the hand. J Bone Joint Surg Am 49:637–647 13. Hayes CW, Pan HC (1982) High pressure injection injuries to the hand. South Med J 75:1491–1498 14. Lozano-Calderon SA, Mudgal CS, Mudgal S, Ring D (2008) Latex paint-gun injuries of the hand: are the outcomes better? Hand (N Y) 3:340–345. doi:10.1007/s11552-008-9110-6 15. Verhoeven N, Hierner R (2008) High-pressure injection injury of the hand: an often underestimated trauma: case report with study of the literature. Strateg Trauma Limb Reconstr 3:27–33. doi:10.1007/ s11751-008-0029-9
PICTORIAL ESSAY
High-pressure paint gun injury: clinical presentation and imaging findings Greg Peters & Thomas Learch & Eric White & Deborah Forrester
Received: 12 December 2013 / Accepted: 7 February 2014 # Am Soc Emergency Radiol 2014
Abstract High-pressure paint gun injuries are potentially devastating injuries that require emergent surgical incision and drainage. They result from erroneous equipment operation and accidental injection of a variety of substances at pressures high enough to breach the skin. The largely benign superficial appearance masks the extent of the underlying injury. In the absence of an appropriate history, the radiologist must recognize the characteristic radiographic findings and suggest the diagnosis to the clinician. Keywords Paint gun injuries . Phalanges . Radiography
Introduction High-pressure paint gun injuries are potentially devastating injuries that require emergent surgical incision and drainage. They result from erroneous equipment operation and accidental injection of a variety of substances at pressures high enough to breach the skin [1]. The largely benign superficial
appearance masks the extent of the underlying injury. In the absence of an appropriate history, the radiologist may have to suggest the diagnosis to the clinician. The first reported high-pressure injection injury was in 1925 during the repair of a diesel engine fuel injector [2]. Initial literature description of these injuries was in 1937. Despite a lengthy history of occurrence, many health care workers may be unfamiliar with these injuries and their potential consequences. High-pressure paint gun injuries are essentially rare for any one emergency department, accounting for one in 600 hand injuries [3]. Twenty-eight cases were documented within a 7year span at our urban county hospital. Nearly all reported cases involved male occupational injuries and injury to the nondominant second or third digit [4]. The number of unreported cases is difficult to estimate and may be quite large. Prospective or population-based studies are not available at this time [1].
Pathophysiology and clinical findings G. Peters (*) 37610 College Drive #201, Palm Desert, CA 92211, USA e-mail: [email protected] T. Learch S. Mark Taper Foundation Imaging Center, Cedars-Sinai Medical Center, 8700 Beverly Blvd., Suite M-335, Los Angeles, CA 90048, USA e-mail: [email protected] E. White : D. Forrester USC Radiology Department, Keck School of Medicine, 1500 San Pablo Street, Los Angeles, CA 90033, USA E. White e-mail: [email protected] D. Forrester e-mail: [email protected]
High-pressure paint guns are readily available to the average consumer for do-it-yourself projects and painting (Fig. 1). They are used commercially for painting as well as greasing, cleaning, lubricating, and mass inoculation of animals. A pressure of 100 lbs per square inch (psi) is sufficient to breach the skin surface, and these machines are capable of producing pressures between 2,000 and 12,000 psi [4], much of which results from pressure increases created as material is ejected through apertures between 0.18 and 1.0 mm wide [5] (Fig. 2). These extreme pressures can propel injected material through the skin surface and subcutaneous tissues to the bone or along fascial planes, tendon sheaths, and neurovascular bundles. The most commonly injected materials are paint and grease. Other commonly injected substances include paint solvents
Emerg Radiol
Fig. 1 High-pressure paint gun
and fuel oil, while air, water, cement, and animal vaccines have also been reported [1]. Injection injuries most commonly occur due to inexperience or insufficient training and result from attempts at unclogging a gun nozzle. The injury often occurs in young male workers either painting for seasonal work or as day laborers. However, the authors have encountered a professional painter who was injured and was fully aware of the potential dangers of operating this equipment. The typical scenario occurs when the gun aperture clogs. The operator typically holds the gun with the dominant hand and uses the second or third finger of the nondominant hand to clear debris from the nozzle and aperture. The gun tip need not to be in contact with the skin surface to penetrate it, and injury may even occur through a barrier such as a cloth used to clean the nozzle [6]. Accidental discharge has also been reported while reaching
Fig. 2 Paint gun aperture (thin white arrow) and surrounding tip guard (thick white arrow)
for a dropped gun [6]. Even when turned off, these highpressure systems remain a danger until the pressure has dissipated. Complete safety manuals are multilingual, but quick start guides are not. In the authors’ experience, sales personnel have limited knowledge about both operation and safety. Clinical presentation is highly dependent on both the type of injectate as well as time to presentation. The injection pressure, volume, and anatomical level also contribute to injury severity [2]. The wound begins as an innocuous pinpoint entry site with mild symptoms of swelling, allowing for underestimation of its potential for debilitation by both patients and physicians [4] (Fig. 3). Even small amounts of material can lead to compartment syndrome, poor perfusion, and closed space infections resulting in tissue necrosis [2]. Direct tissue damage results from the high-velocity injury, and spread of the injectate follows the path of least resistance. Contaminant most easily spreads locally and from distal to proximal along a digit within tissue planes. Anatomic studies show variation of spread based on the tissues encountered [2]. Deflection off the more superficial fibrous flexor tendon sheaths results in local spread. This usually occurs when injectate encounters the rigid fibrous sheath overlying the phalanges also known as the A (annular) pulley. Injections occurring at the level of either the distal interphalangeal or proximal interphalangeal joints often encounter the more
Fig. 3 A 28-year-old male with pinpoint penetration injury to the volar aspect of the second digit at the distal interphalangeal joint level (arrow)
Emerg Radiol
flexible C (cruciform) pulley and penetrate through to the synovial tendon sheath (Fig. 4). When contaminant reaches the deeper synovial tendon sheaths, it may spread as far as the metacarpophalangeal joint level in the second, third, and fourth digits. If injected into either the first or fifth digit, it may follow the tendon sheaths retrograde to communications with either the radial or ulnar bursae within the hand [7].
Radiographic findings Radiography is the imaging test of choice and does well to identify radiopaque materials (Fig. 5) but may underestimate the extent of dispersion of foreign material [8]. Both latex and the less common oil-based paints are easily seen. Grease may be radiolucent or radiopaque depending on its lead content.
Differential diagnosis With an appropriate history, the diagnosis is easily made. In the absence of an appropriate history, one might consider calcinosis cutis or soft tissue calcifications in the setting of connective tissue disease such as scleroderma or dermatomyositis (Fig. 6). These patients are however more often female and older in age with involvement of multiple fingers. If the injectate is gas, water, or even grease, radiopaque material will be absent, but soft tissue gas will be present with or without an obvious soft tissue laceration or soft tissue swelling.
Fig. 5 a, b A 39-year-old male with paint gun injection injury to the third digit (arrows). The surgeon found an intact flexor tendon sheath, though it is difficult to tell from the radiographs that there was no spread within the tendon sheath
broad-spectrum antibiotics, limb elevation, and referral to orthopedics for immediate debridement [2]. Local anesthetics, including digital blocks, are contraindicated as they may raise compartment pressures [2, 9]. All nonviable tissue should be
Treatment and follow-up Prompt recognition with early surgical debridement and decompression are mandatory [2]. Treatment in the emergency department includes tetanus prophylaxis, administration of
Fig. 4 Anatomic sketch of the digit flexor tendons and associated tendon pulleys. FDP flexor digitorum profundus; FDS flexor digitorum superficialis; PIP proximal interphalangeal joint; DIP distal interphalangeal joint
Fig. 6 A 46-year-old female. A case for comparison to Fig. 4, with calcinosis cutis in a patient with scleroderma (arrows)
Emerg Radiol
excised, while all viable tissue should be copiously irrigated, and wounds should be left open for possible further debridement [9]. It is not unusual for foreign material to remain, especially foreign material that is adherent to neurovascular bundles [2]. An analysis of 435 cases occurring between 1966 and 2003 showed that steroid administration did not impact the rate of amputation or incidence of infection [10]. The overall rate of amputation was 30 % and particularly related to the location of injury and type of material injected [10]. The amputation risk associated with latex paint was 5 % versus 60 % with oilbased paints [10]. Optimal time for wide surgical debridement was within 6 h of injury [2, 10, 11], although it is difficult to establish a benchmark. Other studies have documented an amputation rate of approximately 40 % when surgery is performed within 6 h and an amputation rate of 57 % when surgery is delayed beyond 6 h [3, 10–12]. The amputation risk is as high as 87 % without treatment or if treatment is further delayed. Due to the initial benign injury appearance, patients will often delay their initial presentation. An accurate and timely diagnosis is crucial to outcomes. In the absence of amputation, the potential for long-term debilitation is significant. A study of 23 patients followed for an average of 8.5 years after initial injury recorded several complaints affecting activities of daily living and reintegration into the workforce. Neurologic impairments such as cold intolerance, hypersensitivity, paresthesias, and constant pain were the most common. Patients had mild reduction of range of motion and grip strength as well [2]. The permanent partial impairment varies from 4 % for those treated within 6 h versus 17 % for those treated after 6 h [2]. Despite chronic complications of high-pressure injection injury, up to 92 % of workers have returned to their prior jobs [13].
Conclusion High-pressure paint gun injuries are rare but potentially devastating injuries despite the initial benign presentation. They are characterized by a small, punctate skin lesion with potentially severe subcutaneous tissue damage [2]. Radiographs have typical appearances with a limited differential diagnosis. The radiologist should be familiar with the possibility of occult spread along the digit and even into the hand, and alert the often unsuspecting or less experienced surgeon [14]. An immediate wide surgical exploration, debridement, and decompression must be carried out with attempts to remove all foreign material and necrotic tissue [13, 15]. Time to surgical treatment (less than 6 h) and chemical composition of the
injected material are the only factors which are consistently associated with prognosis [3, 6, 10–12]. High-pressure paint guns are potentially very dangerous. Workers, however, continue to use these devices with inadequate training and dangerous technique leading to the ongoing occurrence of injuries. Occupational injury prevention campaigns for communities at risk may decrease the incidence of injury. Given the inconsistent clinical experiences among providers with these types of injuries and the patients’ tendency to underestimate the injury, the radiologist may be required to make the diagnosis. Conflict of interest The authors declare that they have no conflict of interest.
References 1. Dailiana HZ, Kotsaki D, Varitimidis S, Moka S, Bakarozi M, Oikonomou K, Malizos NK (2008) Injection injuries: seemingly minor injuries with major consequences. Hippokratia 12:33–36 2. Harter BT, Harter KC (1986) High pressure injection injuries. Hand Clin 2:547–552 3. Schoo MJ, Scott FA, Boswick JA Jr (1980) High-pressure injection injuries of the hand. J Trauma 20:229–238 4. Hart RG, Smith GD, Haq A (2006) Prevention of high-pressure injection injuries to the hand. Am J Emerg Med 24:73–76 5. Waters WR, Penn I, Ross HM (1967) Airless paint gun injuries of the hand: a clinical and experimental study. Plast Reconstr Surg 39:613– 618 6. Gillespie CA, Rodeheaver GT, Smith S, Edgerton MT, Edlich RF (1974) Airless paint gun injuries: definition and management. Am J Surg 128:383–391 7. Kaufman HD (1968) The anatomy of experimentally produced high pressure injection injuries of the hand. Br J Surg 55:340–344 8. O’Reilly RJ, Blatt G (1975) Accidental high-pressure injection gun injuries of the hand. J Trauma 15:24–31 9. Gonzalez R, Kasdan ML (2006) High pressure injection injuries of the hand. Clin Occup Environ Med 5:407–411 10. Hogan CJ, Ruland RT (2006) High pressure injection injuries to the upper extremity: a review of the literature. J Orthop Trauma 20:503– 511 11. Schnall SB, Mirzayan R (1999) High pressure injection injuries of the hand. Hand Clin 15:245–248 12. Stark HH, Ashworth CR, Boyes JH (1967) Paint-gun injuries of the hand. J Bone Joint Surg Am 49:637–647 13. Hayes CW, Pan HC (1982) High pressure injection injuries to the hand. South Med J 75:1491–1498 14. Lozano-Calderon SA, Mudgal CS, Mudgal S, Ring D (2008) Latex paint-gun injuries of the hand: are the outcomes better? Hand (N Y) 3:340–345. doi:10.1007/s11552-008-9110-6 15. Verhoeven N, Hierner R (2008) High-pressure injection injury of the hand: an often underestimated trauma: case report with study of the literature. Strateg Trauma Limb Reconstr 3:27–33. doi:10.1007/ s11751-008-0029-9
