Alligator attacks,Caiman's bite

CASE REPORT

Year : 2018  |  Volume : 3  |  Issue : 1  |  Page : 24-26

Thoracic trauma by black caiman's bite in the Amazon region

João José Corrêa Bergamasco, Raquel Magalhães Pereira, Juan Eduardo Rios Rodriguez, Brígida Thaine Fernandes Cabral
Department of General Surgery, Getúlio Vargas University Hospital – HUGV, Federal University of Amazonas, Manaus, Amazonas, Brazil

Date of Web Publication

20-Dec-2018

Correspondence Address:

João José Corrêa Bergamasco

Department of General Surgery, Getúlio Vargas University Hospital – HUGV, Federal University of Amazonas, Manaus, Amazonas 
Brazil

Abstract

Alligator attacks are rare, being mostly by accidental causes, for lack of care in regions where the presence of these animals is confirmed or by provocation of them. There are few reports of accidents by these animals. The reported species hereafter is the Melanosuchus niger from the Amazon rainforest. The patient aged 32 years, coming from the countryside of Amazonas, was admitted to the emergency room 3 days after the accident with black caiman's bite. Alligator attacks of the species M. niger are very severe, due to its size around 6 m of length and overwhelming strength, being capable to cause extensive and deep lacerations with its bite. Cases like this are not easy to conduct. Since the injury was on an atypical place, the severity of the symptoms was increased, leading to dyspnea and huge blood loss.

Keywords: Bites and stings, penetrating, wounds, wounds and injuries

Introduction

Alligator attacks are rare, even in the Amazon region, being mostly by accidental causes, for lack of care in regions where the presence of these animals is confirmed or by provocation of them. We must consider that the Amazon region has two species of different genera that are passing through an intense moment of population recovering for the last two decades after a period of predatory exploitation, and they are still the most abundant crocodilians on the region being them the spectacled caiman (Caiman crocodilus) and the black caiman (Melanosuchus niger).^[1] There are few reports of accidents by these animals, most related to smaller species, such as Caiman yacare (Yacare caiman) and Caiman latirostris (broad-snouted caiman). However, the reported species hereafter is the M. niger, or the black caiman, from the Amazon rainforest, it presents a large size compared to the others, and it attacks humans for predation, not being considered just accidents as with other species.^[2],[3] Another important factor to be quoted is the seasonal period of alligator appearance, mostly present on low water level periods of the river, facilitating attacks on the surface; moreover, it is a common period of animals' egg's incubation. At this time of year, there are many other species that feed on these eggs, which increase the rate of aggressive alligators on the surroundings.^[4]

Case Report

The patient, a 32-year-old man, coming from the countryside of Amazonas, was admitted to the emergency room 3 days after the accident with black caiman's bite (M. niger). According to the reports, the victim was fishing in a river near his city on a canoe, followed by his wife on another canoe, when the animal with approximately 5 m length got on the patient's boat, attacking his chest, releasing him only because his wife attacked the alligator with wood pieces. In his admission, he appeared to be slightly dyspneic and has chest pain, respiratory rate of 22 rpm, heartbeat of 106, and normal values of blood pressure.

The physical examination showed extensive lacerations at the left hemithorax [Figure 1] and [Figure 2], with loss of soft parts at the thoracic wall, rib fractures, lung parenchyma exposure, and muscular tissue wounds. The first step was inserted a chest drain of 28 French inside a wound to drain a severe purulent fluid. The leukogram showed a raise of leukocytes rate (20,451).

Figure 1: Thoracic region with wounds sutured or not Click here to view

Figure 2: Extensive thoracic lesions Click here to view

The patient was immediately forwarded to surgery center, where was performed a left anterolateral thoracotomy showing pleural adhesions at the chest wall, pleural cavity cleaning, partial pulmonary decortication, cleaning and debridement of the thoracic wall muscles, partial excision of the ribs (ribs 7/8/9), and a closed chest drain with water seal, associated with collagenase dressing. After 24 h of evolution at intensive care, the vital signals were stable, blood pressure levels were 90/50 mmHg, cardiac frequency: 72 bpm, saturation: 96%, and temperature: 36.5°C, accepting oral diet, without pulmonary symptoms, but with chest tube inserted. Thorax radiography showed opacity at left lung, more intense between superior and inferior lobe [Figure 3]. At the 3^rd day after the surgery, the levels of blood in chest drain had an important decrease but still with bubbles and serous liquid, without smell. At 10 day of postoperatory, thorax radiography was solicited, with a residual opacification between superior and inferior lung lobe [Figure 4]. After 11 days, the drainage tube had no bubbles or serous liquid and was removed after this.

Figure 3: Chest radiography (before surgery) Click here to view

Figure 4: Chest radiography (14 days after surgery) Click here to view

He remained hospitalized for 15 days with parenteral antibiotic therapy (6 days of cefepime +8 days of meropenem) because of extensive and unspecific microbiota of alligator jaws. He evolved well at postoperative, with radiological and drainage volume control, withdrawn at the 14^th day after surgery and decrease of leukocytes levels. Received discharge clinically well with residual pulmonary opacification at the left hemithorax.

Discussion

Alligator attacks of the species M. niger are very severe, due to its size around 6 m of length and overwhelming strength, being capable to cause extensive and deep lacerations with its bite, lethal against children and small-sized people. The main complications due an attack of this kind are tissue lesions that depending on the affected region may compromise functions or losing limbs; blood loss, due the wound depth, hits blood vessels, leading to hypovolemic shock in cases, like the one related above; and infection, due the bacterial flora present in the alligator's mouth.^[5],[6],[7] The most attacked anatomic parts are the inferior limbs, being able to lead to amputation if the initial medical care takes too long.

The early debridement and the hypovolemic and infectious states stabilization are the initial goals on this situation because they are the main causes of death.^[8] It is important to mention that great thoracic traumas are very complicated to handle due the vital organs and easily traumatized when submitted to high strength, like an alligator bite, that can be ranged from 217 to 13,172 N, leading to an increase of the mortality in similar cases, which tends to be the focus of researches in the next years.^[9],[10]

Acknowledging few published reports by trustful sources, a case like the reported above fits in every way like a hard situation to care. Since the injury was on an atypical place (the thorax), the severity of the symptoms was increased, leading to dyspnea and huge blood loss. Added to this, there is the difficulty of the Amazon region, mostly on the riverside communities, which does not have a good emergency support in cases of this magnitude, needing to go to a specialized center, most of the time in Manaus to receive a proper care. So, considering infectious factors, prognosis was poor due to the late beginning of antibiotics and surgical cleaning of the wounds (on the third day after trauma), what makes this case even more relevant for its favorable outcome.

 

References

1.	Vasconcelos WR. Genetic Diversity and Structure Population of Crocodilians Genetic Age and Structure Population of Crocodilians Jacaré-Açú (Melanosuchus niger) and Jacaré-Tinga (Caiman crocodilus) of the Amazon - Dissertation. Manaus - Amazonas National Research Institute of Amazonia.; 2005. p. 1-97.
2.	Langley RL. Alligator attacks on humans in the United States. Wilderness Environ Med 2005;16:119-24.
3.	de Neto MC, Stolf H, Haddad Junior V. Alligator attack on fisherman in the Pantanal of Mato Grosso (Brazil): Case report Diagn Trat 2013;18:21-3.
4.	Torralvo K, Botero-Arias R, Magnusson WE. Temporal variation in black-caiman-nest predation in Varzea of central Brazilian Amazonia. PLoS One 2017;12:e0183476.
5.	Brook I. Management of human and animal bite wound infection: An overview. Curr Infect Dis Rep 2009;11:389-95.
6.	Haddad V, Fonseca WC. Fatal attack on a child by a black caiman (Melanosuchus niger). Wilderness Environ Med 2011;22:62-4.
7.	Sartain SE, Steele RW. An alligator bite. Clin Pediatr (Phila) 2009;48:564-7.
8.	Doering EJ, Fitts CT, Rambo WM, Bradham GB. Alligator bite. JAMA 1971;218:255-6.
9.	Erickson GM, Lappin AK, Parker T, Vliet KA. Comparison of bite-force performance between long-term captive and wild American alligators (Alligator mississippiensis). J Zool 2004;262:21-8.
10.	Grubmüller M, Kerschbaum M, Diepold E, Angerpointner K, Nerlich M, Ernstberger A, et al. Severe thoracic trauma – Still an independent predictor for death in multiple injured patients? Scand J Trauma Resusc Emerg Med 2018;26:6.

Figures

  [Figure 1], [Figure 2], [Figure 3], [Figure 4]