Analysis and post-exposure management of mammalian bite injuries in the Hungarian Central Military Hospital,

Transcription

1 AARMS Vol. 7, No. 3 (2008) MEDICINE Analysis and post-exposure management of mammalian bite injuries in the Hungarian Central Military Hospital, ANDRÁS FEKETE, LAJOS ZSIROS Department of Orthopaedics, Traumatology and Hand Surgery, Hungarian Central Military Hospital, Budapest, Hungary Bite wounds are frequently located on the limbs, mostly on the hands and legs; injuries inflicted by dogs are most common. Here we summarize the statistical results of 1093 (981 ambulant and 112 hospitalized) cases in our hospital (Hungarian Central Military Hospital, Budapest). The median age was 49.5 years (2 9 ys), gender disparity was equal % of the cases were caused by dogs and mostly the limbs (86%) were injured. However most of the cases were polymicrobic, in cat bites the virulent P. multocida was typically shown. The aim of the treatment is primarily to avoid the inflammation or to cure the already existing infection. The main elements of the treatment are the following: meticulous local wound care combined with appropriate antibiotic coverage, tetanus prophylaxis and prevention of rabies. The extensive and increasing contributions of the Hungarian troops are too in part, provide military health support in international military operations. Based on our collected data and clinical experience this study is offering various guidelines for the treatment of mammalian bite injuries, which occur frequently in war- and peacetime as well. Introduction Animal bites (vulnus morsum) are special types of mechanical wounds, where different ratios of typical characteristics of puncture and lacerated wounds can be observed. There are several types of wounds in these cases. Punctured injuries caused by tooth, particularly by the cuspids, sometimes appear to be banal wounds, though there is the danger of failing to diagnose and provide primary treatment for injury of the deeper tissues. The sudden squeezing of the mandible causes compressive, ripping and tearing forces, which can result in extensive tissue injury and damage combined with defect of tissues. Beside mechanical damage, there is a danger of contamination with pathogens living in the animal s saliva, which increase the risk of transmission of different infections (cat-scratch disease, tularaemia, toxoplasmosis, rabies, brucellosis, etc.) 1 and the Received: October 9, 2008 Address for correspondence: ANDRÁS FEKETE feketeandras@hotmail.com

2 development of inflammatory complications. 2 All bite injuries should be considered as potentially infected or seriously contaminated and this should be kept in mind during the treatment. For this reason the importance of tetanus, rabies and antibiotic prophylaxis should be particularly emphasized. According to the current literature animal bites accounts for 1% of all injuries in the outpatient clinic. 3,4,5,6,7 These are mostly dog bites, followed by cats and other mammals (hamster, rat, horse, monkey, fox and other wild animals). 8,9,10,11 In most cases the biting mammals are owned by, or know to, the victim and are vaccinated and observable. Inveterate wounds are very common, because mostly the patients consult a physician only if the symptoms had already worsened, or inflammation can be observed after injuries appearing banal. Considering the body surface, limb injuries, particularly wounds of hands and lower arm are the most frequent, followed by leg injuries. 1,10,12 In young men dog bites are the most common, since in middle-aged women are affected usually by cats. 8,11,12 The age distribution shows that children 1,9 and the middle-aged group are in the greatest risk. Diagnosis Anamnesis The detailed and correct anamnesis is essential; it basically determines the further treatment. The followings should be documented: the type of injuring animal(s), its health condition, vaccination, attainability, perceptibility, the time between the injury and the firstaid, the general condition of the injured person, additional illnesses, regular medication, symptoms, body temperature, tetanus vaccination and mechanism of the injury. Physical and Radiological Examination During the physical examination of the whole body the following should be examined and documented: localization, extent, contamination of the wound and its neighboring tissues (particularly signs of inflammation), neurovascular status and the function of the locomotor system. During the radiological examination additional fractures and foreign bodies should be observed, in cases of inflammation the penetration into the bones and articulation should be analyzed. 524 AARMS 7(3) (2008)

3 Therapy The therapy of bite injuries largely depends on the type of wound: non-infectious or infectious, inveterate. In the first case the major aim is to prevent the inflammation complications, while in the second case the treatment focuses on the therapy of the inflammation and infection. In all cases the best functional and cosmetic results should be aimed for. Most cases can be treated ambulant, but in cases of extensive injury to several parts of the body, or large tissue-surface and/or in inflammatory complications clinical admission could also be needed. Wound care The most important elements of the treatment are based on the asepsis-antisepsis theory of Friedrich, using atraumatic techniques, appropriate anesthesia and in case of limb injuries the tourniquet. The steps of the wound care are as follows: mechanical cleansing, excisional debridement of crushed and devitalized tissues and foreign bodies and irrigation to achieve decontamination by physiologic saline solution, H 2 O 2, solution containing antibiotics. During the treatment special care should be taken to ensure that no closed cavities are left, because the fluid remaining in them is a good soil for the pathogenic bacteria. If such cavities cannot be avoided, they should be carefully drained. It is advisable to treat bite injuries openly, because of increased risk of infection; delayed primary closure can be performed at hours. In case of injury of extensive soft tissues, secondary closure can be applied combined with skin transplantation if necessary. Mildly contaminated and lacerated wounds on the face and hairy scalp are exceptions, because the blood supply of these surfaces is very good and offers total recovery. In these cases primary closure can be performed, but the patient s strict observation under clinical circumstances is also advised, while the mental and social status of the patient should be also taken into consideration. The wound care can be performed in local, regional or total anesthesia depending on the localization and extent of the injury. The primary treatment should be definitive, the additional vascular, neural, tendineal injuries or fractures have to be treated as well by a qualified, experienced specialist. In case of any signs of inflammation operative exploration is advised. Restoration of the lost function can be later performed if it is needed. Beside the primary wound care, the relief of the injured part is also an important element of the prevention of inflammation. AARMS 7(3) (2008) 525

4 Prophylaxis Tetanus: The prophylaxis and vaccination for tetanus caused by the anaerobe Clostridium tetani is the duty of the doctor performing the primary care: active and/or passive immunization with tetanus toxoid and/or human anti-tetanus immunoglobulin according to the current protocols. Lyssa (Rabies): The carriers of rabies virus are wild animals in most cases, but domestic ones can also be involved. The contamination is usually caused by the saliva of the infected animal, so it is very important to prevent the development of the illness in bite injuries. In most cases the injuring animal is known and vaccinated against rabies. In these situations the documents of vaccination should be registered, the animal should be kept under observation by the local veterinarian. If the animal shows symptoms indicating rabies, strays, or dies, the vaccination against rabies should be promptly begin according to the current protocol. If the injuring animal is not known, the same procedure should be performed. It is very important to mention that two independent and diffrent genotypes of lyssaviruses European bat lyssavirus (EBLV) type 1 and type 2 are present in many European countries including in Hugary which can cause fatal disease in humans. 13 According of the data of the National Center of Epidemiology the number of infected animals by lyssa definitively reduced (1216 cases in 1995, 3 in 2006) in Hungary owing to the administration of oral vaccination of foxes. 14 Antimicrobial prophylaxis: According to the current literature antimicrobial prophylaxis significantly reduces the development of inflammation complications in case of bite injuries. 12,15,16,17,18 Even so some groups suggest that antibiotic prophylaxis should be administrated only in the high-risk group of patients. 9,10,19,20 It is generally agreed that the antibiotics should be chosen based on the sensitivity of most common pathogens in animal saliva, which are shown in Table 5. All in all, the first antibiotic group to choose is the β-lactamase-stable penicillin: amoxicillin-clavulanate 1 or ampicillin-sulbactam. 21,22,23 In case of penicillin allergy cephalosporins or clindamycin or ciprofloxacin can be used. Inflammatory complications and their treatment In case of animal bites inflammations are very common because of the penetration of several pathogens through the animal saliva, particularly in lately-treated, inveterate cases. Regarding the risk of development of infectious complications, the injuries can be divided into low-, and high-risk groups. 22,24,25 (See Table 8.) It is important to note that infection can often develop despite only small outward signs. Cat bites on the hands are one of the most risky injuries, with bite or claw marks 526 AARMS 7(3) (2008)

5 appearing banal. Mostly superficial cellulites or abscesses develop, but purulent arthritis and tendovaginitis is also quite common. In some cases osteomyelitis 26 or very rarely lethal sepsis, 27 meningitis, 28 community-acquired pneumonia 29 can occur as well. In the case of superficial inflammatory processes and abscesses, septic exploration with the removal of the inflamed and devitalized tissues and open treatment is advised. After the disappearance of the inflamed signs the wound can be closed. In the case of tendovaginitis or inflammation which penetrates to the articulation, drainage and regular antibiotic lavage is recommended for 4 5 days. Relief of the injured part is important in all cases. First empirical antibiotic administration is proposed, and then a targeted antibiotic depending on the sensitivity of the pathogen is suggested on the basis of microbiological culture. Patient characteristics The statistical results of our ward (Hungarian Central Military Hospital, Department of Orthopaedics, Traumatology and Hand Surgery, Budapest) correlate well with international data. In the 10 years between October, 1995 and 2005 ambulant treatment in 981 of cases (98 cases/year) were performed because of mammalian animal bites (1.35%). The median age was 44.1 years (range 2 93 ys), (children are treated mostly in special pediatric wards!). The number of patients hospitalized because of animal injuries was 112 out of (0.44%) patients (11 cases/years), median age 54.9 years (22 93 ys). The gender, the inflicting animal and the body surface distribution is showed in Tables 1 4. Table 1. Gender distribution of animal injuries Outpatient-clinic (981 cases) In the ward (112 cases) Female 43.5% (427) 50.9% (57) Male 56.5% (554) 49.1% (55) Table 2. Distribution by inflicting animal Outpatient-clinic (981 cases) In the ward (112 cases) Dog 80.53% (790) 83.93% (94) Cat 12.84% (126) 16.07% (18) Other animals 6.63% (65) 0% (0) AARMS 7(3) (2008) 527

6 Table 3. Distribution by body surface Outpatient-clinic (981 cases) In the ward (112 cases) Limbs 86.75% (851) 86.61% (97) Head/face 5.5% (54) 3.57% (4) Others 1.12% (11) 0% (0) Combination 6.63% (65) 9.82% (11) Table 4. Distribution of limb injuries Outpatient-clinic (981 cases) In the ward (112 cases) Upper limb hand 47.71% (468) 55.36% (62) lower arm 12.64% (124) 6.25% (7) upper arm 2.45% (24) 3.57% (4) Lower limb thigh 6.93% (68) 1.78% (2) leg 12.84% (126) 19.64% (22) foot 4.18% (41) 0% (0) In our ward there has been one lethal case of mammalian caused injuries in the last 10 years. A 63-year old man died after four days of Capnocytophaga canimorsus severe sepsis, DIC and multiorgan failure induced by a dog-bite. According to the current literature in most cases the contamination is polymicrobic, it contains aerobic and anaerobic pathogens as well. In cat bites mostly Pasteurella species (including P. multocida) can be isolated. 12 In dog bites the less virulent P. canis and P. stomatis can be shown. Streptococcus and Staphylococcus species are also common (mostly S. aureus), or among anaerobs Fusobacterium and Bacteroides species are present Table 5. Tables 6 7 show the most common pathogens in the wounds of septic patients operated in our ward. Table 5. The most common pathogens in dog and cat bites Aerobic bacteria Pasteurella sp. P. multocida P. canis P. stomatis Streptococcus sp. S. mitis S. mutans Staphylococcus sp. S. aureus S. epidermidis Neisseria sp. Corynebacterium sp. Moraxella sp. Anaerobic bacteria Fusobacterium sp. Bacteroides sp. Porphyromonas sp. Prevotella sp. Propionibacterium sp. Peptostreptococcus sp. 528 AARMS 7(3) (2008)

7 Table 6. Pathogens in dog bites of patients in our ward according to its prevalence Species Staphylococcus aureus Staphylococcuc coagulase negativ Escherchia coli Enterococcus faecalis Enterobacter cloacae Strepococcus G csoport Pasteurella multocida Staphylococcus haemolyticus Steptococcus alpha-haemolyticus Klebsiella sp. Leuconostoc sp. Clostridium perfingens Table 7. Pathogens in cat bites of patients in our ward according to its prevalence Species Pasteurella multocida Enterococcus faecalis Staphylococcus aureus Leuconostoc sp. Table 8. Influencing factors of inflammatory complications Low risk High risk Wound lacerated wounds punctured wounds Localisation head/face hand, wrist, leg, articulation Patient young healthy elderly other diseases : postsplenectomy, diabetes mellitus, immunosuppressive condition, chronic diseases, alcoholism, peripheral vascular disease, malignancy etc. Mammals mostly dog cat Injury new inveterate Table 9 shows the distribution of the patients admitted to our ward in the last 10 years because of inflammatory complications after animal bites. Table 9. Prevalence of inflammatory complications In the ward (81/112 cases) Superficial inflammation 48.15% (39) Tendovaginitis purulenta 30.86% (25) Septic arthritis 11.11% (9) Abscess 7.41% (6) Sepsis 2.47% (2) AARMS 7(3) (2008) 529

8 Discussion Bite wounds are frequently located on the limbs, mostly on the hands and legs; injuries inflicted by dogs are most common. On the hands cat bites are also frequent. In most cases the primary treatment leads to total recovery without any further problems. In inveterate cases the pathogens penetrating with the animal saliva can cause infectious complications. Cat bites are more serious injuries because of the sharp incisive teeth of cats. The primary treatment should be definitive, the additional vascular, neural, tendineal injuries or fractures have to be treated as well. In case of signs of inflammation operative exploration is advised. Restoration of the lost function can be later performed if it is needed. The aim of the treatment is primarily to avoid the inflammation or to cure the already existing infection. The main elements of the treatment are the following: meticulous local wound care combined with appropriate antibiotic coverage, tetanus prophylaxis and prevention of rabies especially in a war zone where the mammalian animals are frequently involved by rabies virus. Based on the current literature and the statistical evaluation of the large population treated in our ward antibiotic prophylaxis as primer care seems to be obviously advisable in all cases of animal bite injuries to avoid later complications and to further improve wound healing. The extensive and increasing contributions of the Hungarian troops are too in part, provide military health support in international military operations. Based on our collected data and clinical experience this study is offering various guidelines for the treatment of mammalian bite injuries, which occur frequently in war- and peacetime as well. References 1. J. PALACIO, M. LEON, S. GARCIA-BELEGUER: Epidemiological aspects of dog bites. Gaceta Sanitaria, 19(1) (2005) J. B. EPSTEIN, C. SCULLY: Mammalian bites: risk and management. American Journal of Dentistry, 5(3) (1992) E. J. GOLDSTEIN, G. A. RICHWALD: Human and animal bite wounds. American Family Physician, 36(1) (1987) R. E. GALLOWAY: Mammalian bites. The Journal of Emergency Medicine, 6(4) (1988) R. D. GRIEGO, T. ROSEN, I. F. ORENGO, J. E. WOLF: Dog, cat, and human bites: a review. Journal of the American Academy of Dermatology, 33(6) (1995) S. DINMAN, D. A. JAROSZ: Managing serious dog bite injuries in children. Pediatric Nursing, 22(5) (1996) I. MEDERIOS, H. SACONATO: Antibiotic prophylaxis for mammalian bites. Cochrane Database of Systematic Reviews, 2 (2001) CD AARMS 7(3) (2008)

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