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High-pressure injection injuries to the hand
High-Pressure Injection Injuries to the Hand DIMITAR VASILEVSKI, MD,* MARK NOORBERGEN, MD,* MICHEL DEPIERREUX, MD,† AND MICHEL LAFONTAINE, MD* High-pressure injection injury hides the true extent of the lesions behind an apparent small and harmless puncture of the finger or the hand. Through clinical description, we wish to point out the need for prompt treatment to avoid mutilating and function-threatening complications. We wish to outline the role of the emergency physician who must be aware of the incidence of high-pressure injection injury and become accustomed to early referral to a surgeon, experienced in extensive surgical exploration, removal of foreign bodies, and rehabilitation. The open-wound technique gives the best results. We also point out that failure to refer may become an increasing focus of negligence claims. (Am J Emerg Med 2000;18:820-824. Copyright r 2000 by W.B. Saunders Company)
First described for fuel oil1,2 and for grease,3 highpressure injection injuries were rare events before the increasingly complex engineering produced by modern industrialization. Many types of hydraulic paint spraying guns and greasing apparatus with a high working pressure have been produced and have led to injuries after breaching the skin from the considerable dissipation of energy and toxic material throughout the tissues. A pressure of about 7 bar (⫽100 psi ⫽ 700 kN/m2 ) can breach the skin4 and most grease guns operate around this pressure. Airless spray-guns work at service pressures around 200 bar/3,000 psi.4,5 The pinpoint nozzle ending the gun shrink the output from 0.18 to 1 mm and fluid may leave at a velocity of 183 m/sec.4,6 A variety of products are now being sprayed through such high-pressure guns, including molten cement, wax, molten metal, hydraulic oil, water, paint, thinner, solvents, and so on. However, many practitioners disregard such injuries, probably on the basis of their initial innocuous appearance. In these cases, delay in adequate management was invariably followed by a worsened functional outcome. We describe two cases, seen in our work-casualties department with various delays since the injury. PATIENTS AND METHODS Case 1 A 37-year-old painter, freelance craftsman, right-handed was admitted to an emergency department (ED), 3 hours From the *Department of Orthopedic Surgery, and the †Department of Anatomopathology, C.H.F.R.—Ce´sar de Paepe, Brussels, Belgium. Manuscript received April 19, 2000, accepted May 4, 2000. Address reprint requests to Dimitar Vasilevski, MD, Avenue Albert, 45 (Forest), B-1190 Brussels, Belgium. E-mail: d.vasilevski@ infonie.be Key Words: Paint gun, high-pressure, injection injury, functional permanent impairment, compartment syndrome of the hand, openwound technique. Copyright r 2000 by W.B. Saunders Company 0735-6757/00/1807-0016$10.00/0 doi:10.1053/ajem.2000.18051 820
after he sustained a work casualty. He was attempting to clean the nozzle of an airless paint gun when he accidentally fired the gun, which operated at a pressure of 200 bar. The gun injected a small amount of one coat acrylic paint, diluted with water. At first, he did not feel any pain. There was a wound on the volar side of the proximal phalanx (P1) of the left thumb, near to the proximal interphalangeal (PIP) joint. Pain grew after about 3 hours and he went to the ED where the physician disregarded this puncture wound, applied a polyvidone iodine dressing, performed a tetanus vaccination and sent him home with some painkillers. The next day the pain worsened and he was admitted to our work-casualties section 28 hours after the initial injury. The thumb was swollen and flexion was impossible because of pain. On the volar aspect of the thumb we could see a small amount of white paint extruding from a puncture wound when we tried to bend the finger. Erythema and induration were prominent from the tip of the thumb to the Thenar prominence and moreover across the volar fold of the wrist. Erythema with no induration extended over the volar aspect of the forearm. There was no evidence of a carpal tunnel involvement or of a compartmental syndrome of the forearm. Plain radiographs showed the dispersion of paint along the proximal phalanx of the thumb (Fig 1). Surgical exploration was performed under general anesthesia and tourniquet procedure. Exsanguination was obtained by surelevation of the limb without the help of an Esmarch’s bandage. We proceeded through a Brunner volar incision for meticulous debridement of the ischemic tissue. White paint tattooed the underlayer of the skin, the tendon sheaths of the flexors longus and brevis of the thumb and surrounded the radial collateral neurovascular bundle. Through a wide opening of the tendon sheaths, we expressed all the white paint. We added a gentle scrubbing and a lavage with a Ringer solution. We took care of the neurovascular bundles and did not try to remove all the pigments from the extremely damaged radial collateral bundle. Anatomopathologic study showed paint infiltrating the tissues, inflammatory response, vessels thrombosis and so on. The tendons sheaths were left open. The edges of the wound were loosely approximated, without tension, over a silicone multitubular drain. We added a bulky dressing, dressed according to the spica pattern to allow gentle mobilization and prevent scar retraction. Rapid mobilization can prevent fibrosis and adherences around the flexors tendons. The patient received antibiotic prophylaxis with clindamycin. The dressing was renewed daily and the patient benefited from a quick rehabilitation program. We used silver sulfadiazine on a sterile fat gauze for the dressings. Cultures were taken at this time and remained sterile. Forearm erythema
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FIGURE 1. Radiology. (A) Plain X-ray film of the thumb showing the distribution of radiodense material in the soft tissues. It helps to delineate the required sites and lengths of surgical incisions and must be obtained each time before surgery. (B) Plain X-ray film of the thumb after surgical debridement. We see the bitubular silicone drain placed in the tendon sheaths of the thumb flexors and going down from the initial wound (located on the volar side of the proximal phalanx) to the thenar prominence.
disappeared in 24 hours after surgery. A central necrose of the wound occurred around the initial puncture injury. Twice a week we repeated iterative debridement and excision of necrotic tissue and tattooed fibrosis. It led to complete excision of the flexor tendons sheaths, tanned by paint. The wound progressively granulated over the excised regions and closure was complete by the 28th postinjury day, allowing the dressings to be stopped. Despite early mobilization, the PIP joint remained stiff with a complete loss of flexion. The thumb suffered a loss of 5° extension in the metacarpophalangeal (MP) joint. Opposition of the thumb was achievable across the tip of the fifth finger but was impossible across the distal interphalangeal (DIP) fold of the fifth finger. Sixth months after injury, the patient complained of hypoesthesia of the scar and radial side of the proximal phalanx of the thumb. He also complained of a loss of strength in holding a hammer and of a loss in his ability to achieve precise acts. The scar remained depressed and adherent. The patient had partially resumed his professional activities on the 28th day after the trauma and completely on the 45th day. He still wore a custom-made silicone dressing
over his thumb when working. His permanent partial impairment (PPI) is estimated at 8%. Case 2 A 43-year-old man, occupied as tramway-engineer, was using a high-pressure grease-spraying gun when the hose of the grease-spraying installation tore itself off, and grease was injected under a pressure of 200 bars into the palm of the distal phalanx (P2) of his right thumb. He was first examined in the ED of a nearby hospital where disinfection was performed. The patient was quickly discharged and sent back home. Pain worsened over the following hours and the patient referred himself to an academic hospital where the practitioner in the ED renewed the dressing and added antibiotics. Finally, the patient came to our work casualties-section where he arrived 8 hours after the accident. Physical examination revealed a diffusely swollen extremity with a small puncture wound over the volar aspect of his right thumb distal phalanx. There was hypoesthesia and impaired vascularity of the thumb, with marked pain on attempted
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extension of the thumb. Plain radiographs revealed extensive deposition of radiodense material and subcutaneous emphysema of the distal part of the thumb. The patient benefited from a complete surgical decompression of the volar aspect of the thumb, extending from the distal phalanx to the metacarpophalangeal volar fold. Postoperatively, the patient presented infection of the operative wound, which necessitated a wide opening of the wound and intravenous antibiotics. The wound was left open under a fat gauze dressing, renewed daily. The patient was discharged to office follow-up on the eighth day after injury. The wound was closed on the 60th day after injury and the patient resumed his work. Eight months after injury, he developed a cheloı¨d and retractile scar, with an oleogranuloma and a secondary fistula. He complained of pain on percussion of the radial collateral nervous bundle of the thumb. Exploratory surgery was performed. An oleagranuloma and a nevroma were excised under magnification. The postoperative course was unremarkable. One year after the injury, the patient still complained of barometric pain and hypoesthesia of the radial side of the distal phalanx of the right thumb. The opposition between the thumb and the other fingers was achievable. The nail and the distal pulp were atrophic but painless under digital pressure. The grip strength was restored. The key pinch was evaluated at 12 kg and was normal. The mobility of the trapezometacarpal joint was assessed and preserved. The flexion of the MP joint was symmetric to the contralateral joint, measured at 68°. The flexion of the PIP joint was limited to 55° (75° on the left thumb). Complete extension of the MP and PIP joint was possible. The patient still wore a custom-made silicone dressing to protect the scar at work. A PPI of 6% was proposed by the insurance company. DISCUSSION Guidelines for Treatment Although high-pressure injection injuries are recognized by traumatologists as serious injuries despite their innocuous initial presentation, their potential morbidity is too frequently unrecognized by the physician in the ED. The reputation of high-pressure injection injuries for being associated with infection, inflammation, fibrosis, disability, and an amputation rate as high as 60% to 80%7-13 must lead us to the following concept: a report of highpressure injection injuries, whatever the initial clinical presentation must be considered as an emergency, widely explored, debrided, and cleaned. We must regard all patients with high-pressure injection injuries of the digits as potential amputees at the time of injury. Therefore most investigators propose that early aggressive treatment by the open wound technique4,9,10,13,14,15 will improve the outcome after highpressure injection injuries. Such an attitude suggests that all patients with high-pressure injection injuries should be referred immediately to surgeons experienced in treatment of work casualties.4,9,10 The surgical technique included wide exposure through a Bruner or mid-lateral incision, an exploration of the tendon sheaths, their eventual partial resection,13,16,17 the debridement of all devitalized tissue and injected material, the
careful preservation of the neurovascular bundles (although the paint cannot be completely removed10,13,18 ), lavage, irrigation, gentle scrubbing, open packing or loose approximation of the edges of the wound, daily renewal of the dressings,4 iterative debridement, early physical therapy program, and reconstructive surgery if needed.4,7,8,9,11,13,14,19 Surgery should be performed under general anesthesia or brachial plexus block. Ring blocks of the finger should be avoided because of the possibility of causing further vascular compression and vasospasm.7 A tourniquet should be applied after the arm has been elevated for 5 minutes.4,7 The Esmarch bandage should never be used for exsanguination of the arm4,7,14,16,20 to avoid further spreading of the injection material along the tendon sheaths and neurovascular bundles. Antibiotics should be added to prevent infection.4,7,10,13,15,20,21 For the first patient we used not only systemic antibiotics (clindamycin) but also Flamazine for its local antiseptic action and the stimulation of granulation offered by such a fat and moist dressing. Some investigators started an anticoagulant therapy in the operating room using heparin I.V., to prevent the extension of the thrombosis of the digital blood vessels.13,22 We can possibly add stellate ganglion blocks to prevent ischaemia caused by vasospasm.16,21 Several investigators reported that steroids may be beneficial when there is an intense inflammatory response or a delay in treatment.15 We did not use steroids in these cases. Anatomic Considerations The site of injury is essential in determining the prognosis.14 Kaufman25 injected hands of cadavers with fine jets of wax emitted from a high-pressure injection gun. He concluded that spread of the injected material depends on the different strengths of the tissue encountered and continued to enter tissues in the line of fire until encountering resistant structures. The flexor sheath is not uniform in consistency. The C-pulleys, overlying the interphalangeal joints are flexible and thin. They allow penetration of the sheath, surrounding of the tendons by the injected material and a worsening of the functional impairment.23 Injections over the middle segments of the fingers encountered the A-pulleys, rigid and fibrous structures overlying the centers of the phalanx and inducing deflection and lateral spread of the injected material in the superficial tissues encircling the digit. They will enhance cutaneous necrosis. Moreover, a peculiar risk encountered by our case 1 patient was the location across the thumb whose synovial sheaths extend proximally into the radial bursae and can lead to a compartment syndrome of the forearm or to a median nerve entrapment at the carpal tunnel site.19,24 Fortunately and because of the relatively quick surgical approach, our patient limited the lesions to the thumb and did not need median nerve release or forearm fasciotomy.19,24 The same matter is encountered at the little finger, where injected material can easily spread retrograde into the ulnar bursa.14,19,23 Injections in less distensible compartments are more risky as also in the fingertips where injections lead more frequently to partial amputation than in palm injuries, presumably because the palm is more expansible and allows a greater dispersion of the material.8,14,23
VASILEVSKI ET AL 䊏 HIGH-PRESSURE INJECTION HAND INJURY
Injection Location The injury typically occurs to the fingertip of the nondominant index finger (D2)7,9,15,19 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 of equipment.4,9 The left hand is at least twice as likely to be involved than the right one.9,19 The next most likely sites are thumb, the first interdigital space and the third digit.9,14,19 The palm is involved in less than 10% of cases.9,19 Contribution of Radiographic Evaluation Plain radiography must be obtained before any surgical approach. It will document the injury and delineate the extent of the spread of foreign body. It will lead us in our surgical planing,15,24,25 helping delineate the required sites and lengths of surgical incisions. Radiography reveals varying distributions of radio-opaque density associated with paint or grease injections, and air density (subcutaneous emphysema) after air or water injection.4,7,10,15,19 The extent of lead-based paint spread is well shown. About the half of the commercially used greases contain lead as a thickening agent to prevent dissolution of the lubrication film under high compression loads. It allows a radiographic visualization of the injected material. Grease and Paint Specificity Fuel and paint injection lead to the most severe inflammatory response with a high amputation rate. Grease and oil-based compounds are more viscous and require higher injection pressures than paint or solvents.4,24 Moreover, grease causes a less severe inflammatory response and leads to oleogranulomas with chronic fistulae formation, scarring and eventual loss of digit function.4,24 The amputation rate is lower, reaching 25% against 60% to 80% for paint or thinner injections.4,10,24 Solvents and thinners are more damaging because of their low viscosity which allows an easier spread of the injected material.14 Paint may contain some high-irritant compounds such as Soya alkyl, which can explain the more intense inflammatory reaction.4 In summary, the paint contains 4 components: a binder, solvents, pigments, and additives. The binder or resin is the solid bulk of the paint and includes various materials such as asphaltics, rubber, epoxies, or acrylics. The pigments are hard, colored particles, including iron oxide, black carbon and phtalocyanine. Binders and pigments essentially form particulate foreign bodies. The solvent makes the paint flowable and additives are chemicals used to achieve properties such as viscosity, hardness, or gloss.18 These chemicals and the basic pH of paint, in the 8 to 9 range, are probably locally toxic and essentially cause a chemical burn. For the same reasons, we avoid the use of solvents for cleansing the wounds.24 In case 1, the paint injected was a water-based paint. Water-based paints include latex, tempera and poster paints (data from industry). They are the less irritating to skin and mucous membranes. Although they are nontoxic, some contain appreciable concentration (5% to 10%) of glycols
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which may lead to potential systemic poisoning. Since 1990 and the prohibition of phenylmercuric acetate as a preservative they have no longer contained mercury. Spray Gun Specificity Airless spray guns became available in the 1950s and quickly gained widespread use.4 Now airless paint guns are commonly used by commercial painters and favored for their properties of high-spray velocity, minimal mist development and the possibility of even dispersal of high viscosity paint.13 The pressure is generated by a hydraulic membrane pump system which creates pressure over 250 bar (25.000 kN/ m2 ).4,8,9,13,19 Paint is forced through a tiny hole in the gun’s nozzle, with a diameter from 0.18 to 1 mm.14,19 Paint leaves the pinpoint nozzle with an excess velocity higher than 180 m/sec.4,7 This spread is close to the muzzle velocity of a rifle7,24 and is sufficient to drive fluids through gloves, coveralls, and skin.7,13 The fluid is injected in relatively nondistensible digital or palmar compartments, in the nondistensible fingertips or in the relatively more distensible dorsal compartments of the hand and forearm.24 In these undistensible compartments, the sudden rise of pressure can be compared with a local blast syndrome propagated in a liquid environment where incompressibility of the environment leads to overpressure by loss of pressure softening. The difference of acceleration observed through tissues of variable densities leads to a sudden compression of the thinnest tissues by the thickness ones. The quick return to the initial balance can lead to avulsions or compressions between tissues.26,27 This is the cause of vascular dilaceration, ischemic necrosis, and gangrene.7 We must also point out the fact that lesions are created by dispersion of kinetic energy through tissues. Following the physical equation, Energy ⫽ 1⁄2 ⫻ Weight ⫻ Speed2, we can easily see that a small amount of fluid with a high speed will quickly increase its kinetic energy. A weight twice as much as the initial one will increase the kinetic energy by two but a speed twice as much as the initial one will increase the kinetic energy by four. This is the cause of the lesions achieved by spray guns, injecting small amounts of paint at a very high speed. Tissue damage, necrosis, and vascular dilaceration will compromise the microcirculation, causing severe ischemic pain and disturbance of sensibility, like a compartment syndrome.19 Without prompt debridement, this stage will end with ischemic gangrene and finger loss. How to Improve the Prognosis Table 1 summarizes the factors that determine the severity of the injury. TABLE 1.
Factors Determining the Severity of the Injury
Type, toxicity, temperature, and viscosity of the injected material Amount of material injected Velocity of the injectant and pressure of appliance Anatomy and distensibility of the injection site Interval between injury and treatment Secondary infection Spread of the injected material
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We can only act on a few factors: the interval before surgery and the prevention of complications such as infection. Moreover we always remember the potential of such injuries for functional impairment and amputation despite prompt aggressive treatment.4,7,8,19 We must point out that amputations become more likely if the delay before debridement reaches 6 hours.4,8 To improve the results, we advocate a rapid diagnosis, prompt surgical management, including an aggressive and extensive approach by the open-wound technique, loose dressings, aggressive and prompt physical therapy, repeated operations.10
disregards the harmful aspect of high-pressure injuries of the hand. We must regard all patients who report digital injection as potential amputees at the time of injury. Such an incident must then lead the patient urgently to the operating room for debridement. The best solution to avoid complications and claims, is an increased understanding of the hazards of these devices by the individuals using them and by emergency staff. REFERENCES
Incidence of Injuries Industry provides many opportunities for these types of injury. Although not rare, these injuries are seen less frequently than many other hand injuries. In 1980 Schoo et al12 reported an estimated incidence of one in 600 injuries seen at their ED. In 1991 Moutet et al9 reported an incidence of 4 cases seen each year in a busy department specialized in hand casualties. Those mostly involved are young male workers, aged from 20 to 40 years.7,14,15 Medicolegal Pitfalls Even with early recognition, this harmful injury leads to significant impairment. Amputation is more likely if debridement is delayed more than 6 hours, especially with low viscosity substances.8,9,19 Amputation rates vary from 16%11 to 55%.4,7,8,9,12 Although fuel, paint, thinner, or solvents injected cause a severe fibrosis leading to 70% amputations,8,24 grease injection mostly cause oleagranulomas, chronic fistulas, and functional loss of the finger without amputation.19,24 The average permanent partial impairment, about 15% in spray-gun injuries is relatively high, especially those injected with paint, thinner and/or solvents.8 Pneumatic hoses injecting air or oil do not cause a significant PPI, less than 2%.8 Hydraulic fluid injuries result in an average PPI of 6%.8 The PPI vary with the mechanism involved in the injury (average PPI of 14% for paint gun and of 6% for hydraulic line), with the site of injection (average PPI of 11% for the digits and of 6% for the palm) and with the delay before surgical decompression (4% PPI if delay is less than 6 hours against 17% if delay is more than 6 hours).8 Because of this, it is important that emergency staff stay aware of the potential dangers of high pressure injuries and the worsening effect of delay before surgery. It must be brought to physicians attention that failure to refer early is becoming an increasing focus of negligence claims.4 The open-wound technique appears to be the most effective, salvaging 84% of the fingers, and restoring normal hand function in more than 60% of patients.9,10 Work loss ranges from 6 to 26 weeks.8,9 Of the patients 92% return to their previous jobs.8 These indications may be useful for the practitioner in estimating the prognosis of such injuries, especially for young and freelance workers. CONCLUSION The true extent of the injury is often hidden behind a tiny skin mark and is not recognized by the physician, who
1. Hesse E: Die chirurgische und gerechtlich-medizinische Bedeutung der Ku¨nstlich hervorgerufenen Erkrankungen. Arch Klin Chir 1925;136:277 2. Rees CE: Penetration of tissue by fuel oil under high-pressure from diesel engine. JAMA 1937;109:866 3. Smith FH: Penetration of tissue by grease under pressure of 7000 Pounds. JAMA 1939;118:907 4. Neal NC, Burke FD: High-pressure injection injuries. Injury 1991;22:467-470 5. Scott AR: Occupational high-pressure injection injury: Pathogenesis and prevention. J Soc Occup Med 1983;33:56 6. McClinton MA, Wright S: High-pressure tool injection injuries. MD Med J 1985;34:289-291 7. Flotre M: High-pressure injection injuries of the hand. Am Fam Phys 1992;45:2230-2234 8. Hayes CW, Pan HC: High-pressure injection injuries of the hand. South Med J 1982;75:1491-1498 9. Moutet F, Lantuejoul JP, Guinard D, et al: Caracte`re d’urgence et de gravite´ des le´sions dues aux injections a` haute pression au niveau de la main. Ann Chir Main 1991;10:476-481 10. Pinto MR, Turkula-Pinto LD, Cooney WP, et al: High-pressure injection injuries of the hand: Review of 25 patients managed by open wound technique. J Hand Surg Am 1993;18:125-130 11. Ramos H, Posch JL, Lie KK: High-pressure injection injuries of the hand. Plast Reconstr Surg 1970;45:221-226 12. Schoo MJ, Scott FA, Boswick JA: High-pressure injection injuries of the hand. J Trauma 1980;20:229-238 13. Vente JP, Bolhuis RJ: Airless paint-gun injuries of the hand: A report of three cases. Injury 1984;16:91-93 14. Harter BT, Harter KC: High-pressure injection injuries. Hand Clin 1986;2:547-552 15. Pai CH, Wei DC, Hou SP: High-pressure injection injuries of the hand. J Trauma 1991;31:110-112 16. Scher C, Schuh FD, Shand HJ: High-pressure paint gun injuries of the hand, a report of two cases. Br J Plast Surg 1973;26:167 17. Starck HH, Ashworth CR, Boyes JH: Paint gun injuries of the hand. J Bone Joint Surg Am 1967;49:637 18. 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 1997;22:156-159 19. Kartlbauer A, Gasperschitz F: High-pressure injection injury: A hand-threatening emergency. J Emerg Med 1987;5:375-379 20. Kaufman HD: The clinico-pathological correlation of highpressure injection injuries. Br J Surg 1968;55:214 21. Nahigian SH: Airless spray gun, a new hand hazard. JAMA 1966;195:688 22. Poldermans LJ: Handverwondingen door hoge druk pistolen. Ned Tijdschr Geneeskd 1977;121:741 23. Kaufman HD: High-pressure injection injuries: The problems, pathogenesis and management. Hand 1970;2:63 24. Geller ER, Gursel E: A unique case of high-pressure injection injury of the hand. J Trauma 1986;26:483-485 25. Pick RY: The roentgenographic appearance of lead paint as a foreign body. Clin Orthop Rel Res 1980;305-306 26. Cudennec YF: Blast, in Carli P, Riou B (eds): Urgences me´dico-chirurgicales de l’adulte. Paris, Arnette, 1991, p 691 27. Lilis R, Green SM, Field J, et al: Paint spray gun injury of the hand. JAMA 1981;246:1233-1235
First described for fuel oil1,2 and for grease,3 highpressure injection injuries were rare events before the increasingly complex engineering produced by modern industrialization. Many types of hydraulic paint spraying guns and greasing apparatus with a high working pressure have been produced and have led to injuries after breaching the skin from the considerable dissipation of energy and toxic material throughout the tissues. A pressure of about 7 bar (⫽100 psi ⫽ 700 kN/m2 ) can breach the skin4 and most grease guns operate around this pressure. Airless spray-guns work at service pressures around 200 bar/3,000 psi.4,5 The pinpoint nozzle ending the gun shrink the output from 0.18 to 1 mm and fluid may leave at a velocity of 183 m/sec.4,6 A variety of products are now being sprayed through such high-pressure guns, including molten cement, wax, molten metal, hydraulic oil, water, paint, thinner, solvents, and so on. However, many practitioners disregard such injuries, probably on the basis of their initial innocuous appearance. In these cases, delay in adequate management was invariably followed by a worsened functional outcome. We describe two cases, seen in our work-casualties department with various delays since the injury. PATIENTS AND METHODS Case 1 A 37-year-old painter, freelance craftsman, right-handed was admitted to an emergency department (ED), 3 hours From the *Department of Orthopedic Surgery, and the †Department of Anatomopathology, C.H.F.R.—Ce´sar de Paepe, Brussels, Belgium. Manuscript received April 19, 2000, accepted May 4, 2000. Address reprint requests to Dimitar Vasilevski, MD, Avenue Albert, 45 (Forest), B-1190 Brussels, Belgium. E-mail: d.vasilevski@ infonie.be Key Words: Paint gun, high-pressure, injection injury, functional permanent impairment, compartment syndrome of the hand, openwound technique. Copyright r 2000 by W.B. Saunders Company 0735-6757/00/1807-0016$10.00/0 doi:10.1053/ajem.2000.18051 820
after he sustained a work casualty. He was attempting to clean the nozzle of an airless paint gun when he accidentally fired the gun, which operated at a pressure of 200 bar. The gun injected a small amount of one coat acrylic paint, diluted with water. At first, he did not feel any pain. There was a wound on the volar side of the proximal phalanx (P1) of the left thumb, near to the proximal interphalangeal (PIP) joint. Pain grew after about 3 hours and he went to the ED where the physician disregarded this puncture wound, applied a polyvidone iodine dressing, performed a tetanus vaccination and sent him home with some painkillers. The next day the pain worsened and he was admitted to our work-casualties section 28 hours after the initial injury. The thumb was swollen and flexion was impossible because of pain. On the volar aspect of the thumb we could see a small amount of white paint extruding from a puncture wound when we tried to bend the finger. Erythema and induration were prominent from the tip of the thumb to the Thenar prominence and moreover across the volar fold of the wrist. Erythema with no induration extended over the volar aspect of the forearm. There was no evidence of a carpal tunnel involvement or of a compartmental syndrome of the forearm. Plain radiographs showed the dispersion of paint along the proximal phalanx of the thumb (Fig 1). Surgical exploration was performed under general anesthesia and tourniquet procedure. Exsanguination was obtained by surelevation of the limb without the help of an Esmarch’s bandage. We proceeded through a Brunner volar incision for meticulous debridement of the ischemic tissue. White paint tattooed the underlayer of the skin, the tendon sheaths of the flexors longus and brevis of the thumb and surrounded the radial collateral neurovascular bundle. Through a wide opening of the tendon sheaths, we expressed all the white paint. We added a gentle scrubbing and a lavage with a Ringer solution. We took care of the neurovascular bundles and did not try to remove all the pigments from the extremely damaged radial collateral bundle. Anatomopathologic study showed paint infiltrating the tissues, inflammatory response, vessels thrombosis and so on. The tendons sheaths were left open. The edges of the wound were loosely approximated, without tension, over a silicone multitubular drain. We added a bulky dressing, dressed according to the spica pattern to allow gentle mobilization and prevent scar retraction. Rapid mobilization can prevent fibrosis and adherences around the flexors tendons. The patient received antibiotic prophylaxis with clindamycin. The dressing was renewed daily and the patient benefited from a quick rehabilitation program. We used silver sulfadiazine on a sterile fat gauze for the dressings. Cultures were taken at this time and remained sterile. Forearm erythema
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FIGURE 1. Radiology. (A) Plain X-ray film of the thumb showing the distribution of radiodense material in the soft tissues. It helps to delineate the required sites and lengths of surgical incisions and must be obtained each time before surgery. (B) Plain X-ray film of the thumb after surgical debridement. We see the bitubular silicone drain placed in the tendon sheaths of the thumb flexors and going down from the initial wound (located on the volar side of the proximal phalanx) to the thenar prominence.
disappeared in 24 hours after surgery. A central necrose of the wound occurred around the initial puncture injury. Twice a week we repeated iterative debridement and excision of necrotic tissue and tattooed fibrosis. It led to complete excision of the flexor tendons sheaths, tanned by paint. The wound progressively granulated over the excised regions and closure was complete by the 28th postinjury day, allowing the dressings to be stopped. Despite early mobilization, the PIP joint remained stiff with a complete loss of flexion. The thumb suffered a loss of 5° extension in the metacarpophalangeal (MP) joint. Opposition of the thumb was achievable across the tip of the fifth finger but was impossible across the distal interphalangeal (DIP) fold of the fifth finger. Sixth months after injury, the patient complained of hypoesthesia of the scar and radial side of the proximal phalanx of the thumb. He also complained of a loss of strength in holding a hammer and of a loss in his ability to achieve precise acts. The scar remained depressed and adherent. The patient had partially resumed his professional activities on the 28th day after the trauma and completely on the 45th day. He still wore a custom-made silicone dressing
over his thumb when working. His permanent partial impairment (PPI) is estimated at 8%. Case 2 A 43-year-old man, occupied as tramway-engineer, was using a high-pressure grease-spraying gun when the hose of the grease-spraying installation tore itself off, and grease was injected under a pressure of 200 bars into the palm of the distal phalanx (P2) of his right thumb. He was first examined in the ED of a nearby hospital where disinfection was performed. The patient was quickly discharged and sent back home. Pain worsened over the following hours and the patient referred himself to an academic hospital where the practitioner in the ED renewed the dressing and added antibiotics. Finally, the patient came to our work casualties-section where he arrived 8 hours after the accident. Physical examination revealed a diffusely swollen extremity with a small puncture wound over the volar aspect of his right thumb distal phalanx. There was hypoesthesia and impaired vascularity of the thumb, with marked pain on attempted
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extension of the thumb. Plain radiographs revealed extensive deposition of radiodense material and subcutaneous emphysema of the distal part of the thumb. The patient benefited from a complete surgical decompression of the volar aspect of the thumb, extending from the distal phalanx to the metacarpophalangeal volar fold. Postoperatively, the patient presented infection of the operative wound, which necessitated a wide opening of the wound and intravenous antibiotics. The wound was left open under a fat gauze dressing, renewed daily. The patient was discharged to office follow-up on the eighth day after injury. The wound was closed on the 60th day after injury and the patient resumed his work. Eight months after injury, he developed a cheloı¨d and retractile scar, with an oleogranuloma and a secondary fistula. He complained of pain on percussion of the radial collateral nervous bundle of the thumb. Exploratory surgery was performed. An oleagranuloma and a nevroma were excised under magnification. The postoperative course was unremarkable. One year after the injury, the patient still complained of barometric pain and hypoesthesia of the radial side of the distal phalanx of the right thumb. The opposition between the thumb and the other fingers was achievable. The nail and the distal pulp were atrophic but painless under digital pressure. The grip strength was restored. The key pinch was evaluated at 12 kg and was normal. The mobility of the trapezometacarpal joint was assessed and preserved. The flexion of the MP joint was symmetric to the contralateral joint, measured at 68°. The flexion of the PIP joint was limited to 55° (75° on the left thumb). Complete extension of the MP and PIP joint was possible. The patient still wore a custom-made silicone dressing to protect the scar at work. A PPI of 6% was proposed by the insurance company. DISCUSSION Guidelines for Treatment Although high-pressure injection injuries are recognized by traumatologists as serious injuries despite their innocuous initial presentation, their potential morbidity is too frequently unrecognized by the physician in the ED. The reputation of high-pressure injection injuries for being associated with infection, inflammation, fibrosis, disability, and an amputation rate as high as 60% to 80%7-13 must lead us to the following concept: a report of highpressure injection injuries, whatever the initial clinical presentation must be considered as an emergency, widely explored, debrided, and cleaned. We must regard all patients with high-pressure injection injuries of the digits as potential amputees at the time of injury. Therefore most investigators propose that early aggressive treatment by the open wound technique4,9,10,13,14,15 will improve the outcome after highpressure injection injuries. Such an attitude suggests that all patients with high-pressure injection injuries should be referred immediately to surgeons experienced in treatment of work casualties.4,9,10 The surgical technique included wide exposure through a Bruner or mid-lateral incision, an exploration of the tendon sheaths, their eventual partial resection,13,16,17 the debridement of all devitalized tissue and injected material, the
careful preservation of the neurovascular bundles (although the paint cannot be completely removed10,13,18 ), lavage, irrigation, gentle scrubbing, open packing or loose approximation of the edges of the wound, daily renewal of the dressings,4 iterative debridement, early physical therapy program, and reconstructive surgery if needed.4,7,8,9,11,13,14,19 Surgery should be performed under general anesthesia or brachial plexus block. Ring blocks of the finger should be avoided because of the possibility of causing further vascular compression and vasospasm.7 A tourniquet should be applied after the arm has been elevated for 5 minutes.4,7 The Esmarch bandage should never be used for exsanguination of the arm4,7,14,16,20 to avoid further spreading of the injection material along the tendon sheaths and neurovascular bundles. Antibiotics should be added to prevent infection.4,7,10,13,15,20,21 For the first patient we used not only systemic antibiotics (clindamycin) but also Flamazine for its local antiseptic action and the stimulation of granulation offered by such a fat and moist dressing. Some investigators started an anticoagulant therapy in the operating room using heparin I.V., to prevent the extension of the thrombosis of the digital blood vessels.13,22 We can possibly add stellate ganglion blocks to prevent ischaemia caused by vasospasm.16,21 Several investigators reported that steroids may be beneficial when there is an intense inflammatory response or a delay in treatment.15 We did not use steroids in these cases. Anatomic Considerations The site of injury is essential in determining the prognosis.14 Kaufman25 injected hands of cadavers with fine jets of wax emitted from a high-pressure injection gun. He concluded that spread of the injected material depends on the different strengths of the tissue encountered and continued to enter tissues in the line of fire until encountering resistant structures. The flexor sheath is not uniform in consistency. The C-pulleys, overlying the interphalangeal joints are flexible and thin. They allow penetration of the sheath, surrounding of the tendons by the injected material and a worsening of the functional impairment.23 Injections over the middle segments of the fingers encountered the A-pulleys, rigid and fibrous structures overlying the centers of the phalanx and inducing deflection and lateral spread of the injected material in the superficial tissues encircling the digit. They will enhance cutaneous necrosis. Moreover, a peculiar risk encountered by our case 1 patient was the location across the thumb whose synovial sheaths extend proximally into the radial bursae and can lead to a compartment syndrome of the forearm or to a median nerve entrapment at the carpal tunnel site.19,24 Fortunately and because of the relatively quick surgical approach, our patient limited the lesions to the thumb and did not need median nerve release or forearm fasciotomy.19,24 The same matter is encountered at the little finger, where injected material can easily spread retrograde into the ulnar bursa.14,19,23 Injections in less distensible compartments are more risky as also in the fingertips where injections lead more frequently to partial amputation than in palm injuries, presumably because the palm is more expansible and allows a greater dispersion of the material.8,14,23
VASILEVSKI ET AL 䊏 HIGH-PRESSURE INJECTION HAND INJURY
Injection Location The injury typically occurs to the fingertip of the nondominant index finger (D2)7,9,15,19 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 of equipment.4,9 The left hand is at least twice as likely to be involved than the right one.9,19 The next most likely sites are thumb, the first interdigital space and the third digit.9,14,19 The palm is involved in less than 10% of cases.9,19 Contribution of Radiographic Evaluation Plain radiography must be obtained before any surgical approach. It will document the injury and delineate the extent of the spread of foreign body. It will lead us in our surgical planing,15,24,25 helping delineate the required sites and lengths of surgical incisions. Radiography reveals varying distributions of radio-opaque density associated with paint or grease injections, and air density (subcutaneous emphysema) after air or water injection.4,7,10,15,19 The extent of lead-based paint spread is well shown. About the half of the commercially used greases contain lead as a thickening agent to prevent dissolution of the lubrication film under high compression loads. It allows a radiographic visualization of the injected material. Grease and Paint Specificity Fuel and paint injection lead to the most severe inflammatory response with a high amputation rate. Grease and oil-based compounds are more viscous and require higher injection pressures than paint or solvents.4,24 Moreover, grease causes a less severe inflammatory response and leads to oleogranulomas with chronic fistulae formation, scarring and eventual loss of digit function.4,24 The amputation rate is lower, reaching 25% against 60% to 80% for paint or thinner injections.4,10,24 Solvents and thinners are more damaging because of their low viscosity which allows an easier spread of the injected material.14 Paint may contain some high-irritant compounds such as Soya alkyl, which can explain the more intense inflammatory reaction.4 In summary, the paint contains 4 components: a binder, solvents, pigments, and additives. The binder or resin is the solid bulk of the paint and includes various materials such as asphaltics, rubber, epoxies, or acrylics. The pigments are hard, colored particles, including iron oxide, black carbon and phtalocyanine. Binders and pigments essentially form particulate foreign bodies. The solvent makes the paint flowable and additives are chemicals used to achieve properties such as viscosity, hardness, or gloss.18 These chemicals and the basic pH of paint, in the 8 to 9 range, are probably locally toxic and essentially cause a chemical burn. For the same reasons, we avoid the use of solvents for cleansing the wounds.24 In case 1, the paint injected was a water-based paint. Water-based paints include latex, tempera and poster paints (data from industry). They are the less irritating to skin and mucous membranes. Although they are nontoxic, some contain appreciable concentration (5% to 10%) of glycols
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which may lead to potential systemic poisoning. Since 1990 and the prohibition of phenylmercuric acetate as a preservative they have no longer contained mercury. Spray Gun Specificity Airless spray guns became available in the 1950s and quickly gained widespread use.4 Now airless paint guns are commonly used by commercial painters and favored for their properties of high-spray velocity, minimal mist development and the possibility of even dispersal of high viscosity paint.13 The pressure is generated by a hydraulic membrane pump system which creates pressure over 250 bar (25.000 kN/ m2 ).4,8,9,13,19 Paint is forced through a tiny hole in the gun’s nozzle, with a diameter from 0.18 to 1 mm.14,19 Paint leaves the pinpoint nozzle with an excess velocity higher than 180 m/sec.4,7 This spread is close to the muzzle velocity of a rifle7,24 and is sufficient to drive fluids through gloves, coveralls, and skin.7,13 The fluid is injected in relatively nondistensible digital or palmar compartments, in the nondistensible fingertips or in the relatively more distensible dorsal compartments of the hand and forearm.24 In these undistensible compartments, the sudden rise of pressure can be compared with a local blast syndrome propagated in a liquid environment where incompressibility of the environment leads to overpressure by loss of pressure softening. The difference of acceleration observed through tissues of variable densities leads to a sudden compression of the thinnest tissues by the thickness ones. The quick return to the initial balance can lead to avulsions or compressions between tissues.26,27 This is the cause of vascular dilaceration, ischemic necrosis, and gangrene.7 We must also point out the fact that lesions are created by dispersion of kinetic energy through tissues. Following the physical equation, Energy ⫽ 1⁄2 ⫻ Weight ⫻ Speed2, we can easily see that a small amount of fluid with a high speed will quickly increase its kinetic energy. A weight twice as much as the initial one will increase the kinetic energy by two but a speed twice as much as the initial one will increase the kinetic energy by four. This is the cause of the lesions achieved by spray guns, injecting small amounts of paint at a very high speed. Tissue damage, necrosis, and vascular dilaceration will compromise the microcirculation, causing severe ischemic pain and disturbance of sensibility, like a compartment syndrome.19 Without prompt debridement, this stage will end with ischemic gangrene and finger loss. How to Improve the Prognosis Table 1 summarizes the factors that determine the severity of the injury. TABLE 1.
Factors Determining the Severity of the Injury
Type, toxicity, temperature, and viscosity of the injected material Amount of material injected Velocity of the injectant and pressure of appliance Anatomy and distensibility of the injection site Interval between injury and treatment Secondary infection Spread of the injected material
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We can only act on a few factors: the interval before surgery and the prevention of complications such as infection. Moreover we always remember the potential of such injuries for functional impairment and amputation despite prompt aggressive treatment.4,7,8,19 We must point out that amputations become more likely if the delay before debridement reaches 6 hours.4,8 To improve the results, we advocate a rapid diagnosis, prompt surgical management, including an aggressive and extensive approach by the open-wound technique, loose dressings, aggressive and prompt physical therapy, repeated operations.10
disregards the harmful aspect of high-pressure injuries of the hand. We must regard all patients who report digital injection as potential amputees at the time of injury. Such an incident must then lead the patient urgently to the operating room for debridement. The best solution to avoid complications and claims, is an increased understanding of the hazards of these devices by the individuals using them and by emergency staff. REFERENCES
Incidence of Injuries Industry provides many opportunities for these types of injury. Although not rare, these injuries are seen less frequently than many other hand injuries. In 1980 Schoo et al12 reported an estimated incidence of one in 600 injuries seen at their ED. In 1991 Moutet et al9 reported an incidence of 4 cases seen each year in a busy department specialized in hand casualties. Those mostly involved are young male workers, aged from 20 to 40 years.7,14,15 Medicolegal Pitfalls Even with early recognition, this harmful injury leads to significant impairment. Amputation is more likely if debridement is delayed more than 6 hours, especially with low viscosity substances.8,9,19 Amputation rates vary from 16%11 to 55%.4,7,8,9,12 Although fuel, paint, thinner, or solvents injected cause a severe fibrosis leading to 70% amputations,8,24 grease injection mostly cause oleagranulomas, chronic fistulas, and functional loss of the finger without amputation.19,24 The average permanent partial impairment, about 15% in spray-gun injuries is relatively high, especially those injected with paint, thinner and/or solvents.8 Pneumatic hoses injecting air or oil do not cause a significant PPI, less than 2%.8 Hydraulic fluid injuries result in an average PPI of 6%.8 The PPI vary with the mechanism involved in the injury (average PPI of 14% for paint gun and of 6% for hydraulic line), with the site of injection (average PPI of 11% for the digits and of 6% for the palm) and with the delay before surgical decompression (4% PPI if delay is less than 6 hours against 17% if delay is more than 6 hours).8 Because of this, it is important that emergency staff stay aware of the potential dangers of high pressure injuries and the worsening effect of delay before surgery. It must be brought to physicians attention that failure to refer early is becoming an increasing focus of negligence claims.4 The open-wound technique appears to be the most effective, salvaging 84% of the fingers, and restoring normal hand function in more than 60% of patients.9,10 Work loss ranges from 6 to 26 weeks.8,9 Of the patients 92% return to their previous jobs.8 These indications may be useful for the practitioner in estimating the prognosis of such injuries, especially for young and freelance workers. CONCLUSION The true extent of the injury is often hidden behind a tiny skin mark and is not recognized by the physician, who
1. Hesse E: Die chirurgische und gerechtlich-medizinische Bedeutung der Ku¨nstlich hervorgerufenen Erkrankungen. Arch Klin Chir 1925;136:277 2. Rees CE: Penetration of tissue by fuel oil under high-pressure from diesel engine. JAMA 1937;109:866 3. Smith FH: Penetration of tissue by grease under pressure of 7000 Pounds. JAMA 1939;118:907 4. Neal NC, Burke FD: High-pressure injection injuries. Injury 1991;22:467-470 5. Scott AR: Occupational high-pressure injection injury: Pathogenesis and prevention. J Soc Occup Med 1983;33:56 6. McClinton MA, Wright S: High-pressure tool injection injuries. MD Med J 1985;34:289-291 7. Flotre M: High-pressure injection injuries of the hand. Am Fam Phys 1992;45:2230-2234 8. Hayes CW, Pan HC: High-pressure injection injuries of the hand. South Med J 1982;75:1491-1498 9. Moutet F, Lantuejoul JP, Guinard D, et al: Caracte`re d’urgence et de gravite´ des le´sions dues aux injections a` haute pression au niveau de la main. Ann Chir Main 1991;10:476-481 10. Pinto MR, Turkula-Pinto LD, Cooney WP, et al: High-pressure injection injuries of the hand: Review of 25 patients managed by open wound technique. J Hand Surg Am 1993;18:125-130 11. Ramos H, Posch JL, Lie KK: High-pressure injection injuries of the hand. Plast Reconstr Surg 1970;45:221-226 12. Schoo MJ, Scott FA, Boswick JA: High-pressure injection injuries of the hand. J Trauma 1980;20:229-238 13. Vente JP, Bolhuis RJ: Airless paint-gun injuries of the hand: A report of three cases. Injury 1984;16:91-93 14. Harter BT, Harter KC: High-pressure injection injuries. Hand Clin 1986;2:547-552 15. Pai CH, Wei DC, Hou SP: High-pressure injection injuries of the hand. J Trauma 1991;31:110-112 16. Scher C, Schuh FD, Shand HJ: High-pressure paint gun injuries of the hand, a report of two cases. Br J Plast Surg 1973;26:167 17. Starck HH, Ashworth CR, Boyes JH: Paint gun injuries of the hand. J Bone Joint Surg Am 1967;49:637 18. 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 1997;22:156-159 19. Kartlbauer A, Gasperschitz F: High-pressure injection injury: A hand-threatening emergency. J Emerg Med 1987;5:375-379 20. Kaufman HD: The clinico-pathological correlation of highpressure injection injuries. Br J Surg 1968;55:214 21. Nahigian SH: Airless spray gun, a new hand hazard. JAMA 1966;195:688 22. Poldermans LJ: Handverwondingen door hoge druk pistolen. Ned Tijdschr Geneeskd 1977;121:741 23. Kaufman HD: High-pressure injection injuries: The problems, pathogenesis and management. Hand 1970;2:63 24. Geller ER, Gursel E: A unique case of high-pressure injection injury of the hand. J Trauma 1986;26:483-485 25. Pick RY: The roentgenographic appearance of lead paint as a foreign body. Clin Orthop Rel Res 1980;305-306 26. Cudennec YF: Blast, in Carli P, Riou B (eds): Urgences me´dico-chirurgicales de l’adulte. Paris, Arnette, 1991, p 691 27. Lilis R, Green SM, Field J, et al: Paint spray gun injury of the hand. JAMA 1981;246:1233-1235