You are in: eMedicine Specialties > Orthopedic Surgery > HAND AND UPPER EXTREMITY High-Pressure Injection InjuriesArticle Last Updated: Feb 19, 2008AUTHOR AND EDITOR INFORMATIONSection 1 of 11
  Author: Jugpal S Arneja, MD, Assistant Professor, Section of Plastic Surgery, Wayne State University School of Medicine; Consulting Staff, Section of Plastic Surgery, Children's Hospital of Michigan, Detroit Medical Center Affiliated Hospitals Jugpal S Arneja is a member of the following medical societies: American Academy of Pediatrics, American Burn Association, American Cleft Palate/Craniofacial Association, American College of Surgeons, American Society of Maxillofacial Surgeons, American Society of Plastic Surgeons, Canadian Medical Association, Canadian Society of Plastic Surgeons, and Royal College of Physicians and Surgeons of Canada Coauthor(s): William Rennie, MD, Professor of Surgery, University of Manitoba; Head, Section of Orthopedic Surgery, Health Sciences Center of Winnipeg; RB Turner, MD, FRCSC, Assistant Professor, Section of Plastic Surgery, University of Manitoba; W Reid Waters, MD, CM, FRCPSC, FACS, Associate Professor of Surgery, University of Manitoba; Former Head of Plastic Surgery Section, Winnipeg Regional Health Authority; Jonathan Toy, MD, Resident, Department of Surgery, Division of Plastic Surgery, University of Alberta Faculty of Medicine and Dentistry Editors: Peter M Murray, MD, Associate Professor of Orthopedic Surgery, Mayo Clinic College of Medicine; Director of Education, Mayo Foundation for Medical Education and Research, Jacksonville; Consultant, Department of Orthopedic Surgery, Mayo Clinic, Jacksonville; Consulting Staff, Nemours Children's Clinic and Wolfson's Children's Hospital; Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine; Thomas R Hunt III, MD, John D Sherrill Professor of Surgery, Director, Division of Orthopedic Surgery, Surgeon in Chief, UAB Upper Extremity Fellowship, UAB Highlands Hospital, University of Alabama at Birmingham School of Medicine; Dinesh Patel, MD, FACS, Associate Clinical Professor of Orthopedic Surgery, Harvard Medical School; Chief of Arthroscopic Surgery, Department of Orthopedic Surgery, Massachusetts General Hospital; Harris Gellman, MD, Consulting Surgeon, Broward Hand Center, Voluntary Clinical Professor of Orthopedic Surgery and Plastic Surgery, Departments of Orthopedic Surgery and Surgery, University of Miami School of Medicine Author and Editor Disclosure Synonyms and related keywords: HPI injury, hand injury, finger injury INTRODUCTIONSection 2 of 11
  History of the ProcedureIn 1937, Rees published the first reported case of a high-pressure injection (HPI) injury to the finger. This injury involved diesel fuel.1 Prior to Rees's report, FrequencyAlthough over 100 case reports of HPI injuries of the hand can be found in the literature, the incidence of these kinds of cases is difficult to assess. Nonetheless, a group from the EtiologyCommon substances involved in HPI injuries include grease, which accounts for 57% of injuries (at pressures of up to 5,000-10,000 pounds per square inch [psi]), paint (up to 5,000 psi), and diesel fuel (accounting for 14% of injuries, with pressures of up to 2,000-6,000 psi).3, 4 In a 1970 report, Kaufman compared the kinetic energy from a grease gun to a 1000-kg weight falling from a height of 25 cm.5 Injuries with compressed air (at pressures of up to 50-300 psi) and high-pressure water injection (up to 6000-8000 psi) are also seen.6, 7, 8, 9 In recent times, a greater variety of substances are being reported to cause HPI injuries, such as paint, wax, molten metal, air, water, paint thinner, and other solvents.10 PathophysiologyHigh-pressure guns emit jet streams at pressures of up to thousands of psi. At these extreme pressures, material is forced through the skin, where diffusion can occur along fascial planes, tendon sheaths, and neurovascular bundles.11 Various mechanisms can be used to explain the clinical picture of HPI injuries. Ischemia, necrosis from high-velocity mechanical impact, the direct toxic effect of the involved chemical, and infection play major roles in these types of injuries.5, 12, 13, 14 Factors contributing to digital ischemia include massive vessel thrombosis from volatilization of the injected material, temporary vascular spasm as a response to trauma, venous outflow obstruction from tissue distention, and digital artery compression.15 The volume of material injected into a closed space and the resultant edema can exacerbate ischemia.16 The chemical properties of the injected material have a considerable effect on clinical injury. With viscous substances, such as grease and oil-based compounds, dispersion is less marked than it is with more fluid materials. These substances tend not to penetrate the flexor sheath, resulting in infiltration of the surrounding neurovascular bundles. Low viscosity solvents, such as paint thinners, may disperse more readily into the soft tissues. Injection pressure is also reported to be a factor in the extent of injury.8 Some have suggested that the predominant mechanism of tissue damage is chemical irritation and that this is more important than ischemia. Ramos et al concluded that an injection of isotonic sodium chloride solution under high pressure into tissue does not produce a significant inflammatory reaction.17, 14 Clinically, Pai et al noted that injected water did not induce extensive soft-tissue destruction, even when the injury was treated conservatively.18 Paint thinners lead to more extensive damage and may cause lipid dissolution and destruction of tissues, even when not injected under high pressure.12, 19 Also, paints and paint thinners produce the most severe inflammatory responses, leading to high amputation rates.11, 20 Grease has been shown to be associated with oleogranulomata formation (a reaction to foreign bodies), fistula formation, fibrosis, and poor functional outcomes.13, 19, 21 Joint contractures and ankylosis are also seen.3 ClinicalMost frequently, the site of injury is a small puncture wound on the terminal segment of the index finger of the nondominant hand. The average age of the patient at injury is 28.4 years, with an age range of 16-47 years.17 The left hand is twice as likely to be damaged as the right hand.3, 12, 22 A common explanation for this pattern is that, sometimes, inexperienced workers clean the end of a pressure gun with the tip of a finger. The injection can be painless, and the individual may continue to work11, 23; however, these substances may be systemically absorbed and, within hours of injury, may result in fever, leukocytosis, and lymphadenitis.20, 24 The entrance site from HPI injuries is often deceptively small. The injected material acts as a projectile. The physician must look for possible exit sites as well.8 This seemingly benign appearance may lead some clinicians to send the patient home with analgesia and reassurance.25 Invariably, the patient returns to the hospital experiencing excruciating pain and unable to move the involved finger or hand. Depending on the volume and materials injected, the finger may be distended, swollen, and tender on palpation. If vessels in the involved digit have been thrombosed or compressed, the digit may be pale, anesthetic, or even ischemic.17 In the case of an air-injection injury, associated crepitus and subcutaneous emphysema are possible.16 Interestingly, Temple et al reported a case of pneumomediastinum after an injection injury to the hand.26 The severity of the injury is dependent on many factors, including the type, toxicity, temperature, amount, and viscosity of the material injected; the pressure of injection; the involvement of synovial sheaths; the anatomy and distensibility of the injection site; secondary infection; and the time interval between injury and surgery.12, 27 With paint and other solvents, factors affecting dispersion of the material include the pressure of injection, the elasticity of tissue, and the viscosity of the substance itself.24, 28 In addition, the site of penetration can influence the extent of injury.27 Kaufman performed experiments on cadaver hands in which he injected wax at 750 psi.29 By varying the site of injection, he discovered that injection over the fibrous tendon sheath resulted in the injected materials collecting in the tissues around the sheath, rather than within the sheath itself. When the membranous portion of the sheath was involved, the result was filling of the sheath with the injected material. The former situation resulted in extensive neurovascular damage, with spread of the substance through loose subcutaneous tissues and into fascial planes; the latter situation caused the injected material to travel long distances. In some cases, the proximal elbow may be reached along the flexor tendon sheath.29 Injected material may also travel into the deep spaces of the hand.21 Infection following HPI injuries is more commonly seen in digits that have not been treated. Ischemia and necrotic tissue are a haven for the proliferation of microbes. Coincidentally, many materials injected have antimicrobial properties.3, 16 Amputation rates range from 16-55% for HPI injuries.3, 12, 17, 27 A complete history should be obtained that includes the mechanism of injury, the nature of the materials injected, the timeline, and, if possible, the pressure of the machine at the time of injury.23 Following a physical examination of the involved upper extremity that notes circulation in the digit and evaluates for compartment syndrome, further investigations, such as radiographs, may be helpful. Related eMedicine topics: Related Medscape topics: INDICATIONSSection 3 of 11
HPI injuries involving grease and paint are considered surgical emergencies, whereas HPI injuries with other substances require careful clinical evaluation and/or surgical intervention. RELEVANT ANATOMYSection 4 of 11
CONTRAINDICATIONSSection 5 of 11
Clean water and air injuries may result in good functional outcomes with simple monitoring and conservative management (see Intraoperative details). Generally, surgeons should have a low threshold for surgical management of HPI injuries because they are surgical emergencies. WORKUPSection 6 of 11
Lab Studies
Imaging Studies
TREATMENTSection 7 of 11
Medical therapyFollowing a thorough history, physical examination, and additional workup, tetanus prophylaxis, analgesia, and intravenous broad-spectrum antibiotic therapy should be administered.10 Clean water and air injuries may result in good functional outcomes with simple monitoring and conservative management (see Intraoperative details). Surgical therapyHPI injuries are considered surgical emergencies. Surgical consultation should be obtained quickly. Pai et al suggested that the time interval from injury to treatment is a determinant of the eventual result.18 Preoperative detailsAs with other hand injuries, the extremity should be elevated and splinted. With HPI injuries, ice should not be used as a treatment because it promotes vasoconstriction and further exacerbates poor circulation.10 Intraoperative detailsGrease, paint, and other chemicals Following the above procedures, wide surgical decompression with timely debridement of necrotic tissue and foreign material is essential. The patient should be under general anesthesia. Affected digits should be opened using a Brunner incision or midlateral incision through its entire length.11, 20 If material is adherent to the neurovascular bundles and cannot be removed, it should be left in place.23 Intraoperatively, an Esmarch bandage should be avoided for hemostasis because the increased pressure spreads injected materials deeper into the subcutaneous tissues. The use of solvents other than isotonic sodium chloride solution for irrigation of a wound is not recommended.29, 30 Furthermore, digital or local nerve blocks are contraindicated because they increase compartment pressures and are associated with poorer outcomes.31 Returning to the operating room for further irrigation and debridement is recommended, and the wound should be left open.10 Amputation rates range from 16-55% for HPI injuries.3, 12, 17 Some physicians advocate amputation if the damage is severe and paint was injected into a digit. If a digit is initially cool or poorly perfused, consider early amputation.12, 21, 32 Because inflammation plays a key role in the extent of damage following HPI injuries, using steroids as an adjunct has been suggested for severe cases. Bottoms described using dexamethasone as an adjunct.33 Since then, others have concurred with the use of high-dose systemic corticosteroids for HPI injuries, despite the theoretically increased risk of sepsis resulting from immunosuppression. Lewis et al recommended that "steroids should be used with antibiotic coverage in all cases, with the exception of grease gun injuries with minimal tissue extension." Lewis et al argued that the organic chemicals usually injected generally do not support bacterial growth.12 Clean water and air In contrast to HPI injuries with materials such as paint, grease, and other solvents, clean water and air injuries may result in good functional outcomes with simple monitoring and conservative management. In a 1991 report, Peters suggested that, because of the clean and relatively nonirritating nature of the water supply in the city where the injuries were reported, aggressive surgical debridement was not warranted; however, if water from a polluted source is involved, immediate surgical exploration is warranted. HPI injuries with air have also been described as having a benign course.6 Postoperative detailsWith all HPI injuries, physiotherapy in the early postinjury period is imperative for a good functional outcome. Along with this treatment, swelling was found to respond well to the application of intermittent custom-made pressure garments.25 Follow-upFollow-up care should revolve around physical and occupational therapy, social work, and the psychosocial services team, in addition to close follow-up by the hand surgeons. Once maximum physical and occupational therapy and splinting have been achieved by the patient, secondary surgical procedures should be considered. Capsulotomy, neurolysis, tenolysis, and soft-tissue reconstruction are all procedures that can be considered to restore maximal function.12 For excellent patient education materials, see eMedicineHealth's Hand, Wrist, Elbow, and Shoulder Center and the patient education articles Finger Injuries, Hand Injuries, and Puncture Wound. COMPLICATIONSSection 8 of 11
The complications associated with HPI injuries include infection, tenodesis, contracture, amputation, chronic pain, wound healing, abnormal scarring, and limb dysfunction. OUTCOME AND PROGNOSISSection 9 of 11
HPI injuries often manifest as innocuous lesions on the fingertip of a patient's nondominant hand. Depending on the substance involved, these injuries may follow a benign clinical course (for air and clean water) or may be deceptively destructive and lead to soft-tissue necrosis and amputation (for grease and paint). Proper triage and management of HPI injuries of the hand is imperative; the attending physician should recognize grease and paint injuries as surgical emergencies. A delay in treatment may result in inferior functional outcomes.12 In the digits, amputation rates are as high as 48%.3, 12, 17 Overall, HPI injuries result in significant impairment of function and reintegration into the work force, as well as aesthetic damage. The most common long-term impairments include cold intolerance and hypersensitivity; however, grip strength, pinch, range of motion, and 2-point discrimination are also affected.34, 35 MULTIMEDIASection 10 of 11
REFERENCESSection 11 of 11
High-Pressure Injection Injuries excerpt Article Last Updated: Feb 19, 2008 | |||||||||||||||||||||||||||||||||||||||||||||||
