Suicide attempt by the intravenous injection of rattlesnake venom.

Abstract: A 14-year-old male milked the venom from a rattlesnake and injected it with a syringe into his right antecubital vein in a suicide attempt. He immediately developed severe pain and vomiting, then hypotension, swollen lips and tongue, and coma. The injection site did not have the considerable tissue damage seen with severe rattlesnake envenomation. Critical hematological abnormalities, gastrointestinal bleeding, and hematuria developed over 24 hours. He received crotalidae polyvalent immune fab (ovine) antivenom and was discharged after 5 days without sequela. This patient's clinical findings were similar to those seen in patients bitten by rattlesnakes with rare intravenous envenomation.

Key Words: snake, injection, IV, venom, suicide

Case Report

A 14-year-old male was seen vomiting on the side of the road and emergency medical services (EMS) were dispatched. On EMS arrival, the patient stated he had "injected snake into myself" in an apparent suicide attempt. He had killed one of his stepfather's rattlesnakes and removed its head. Based on his description and location, it was probably a western diamondback rattlesnake, Crotalus atrox. He then milked the venom, drew up an unknown amount into a syringe, and injected it into his right antecubital vein. The patient states he had immediate severe pain and began vomiting. Past medical history included attention deficit hyperactivity disorder, oppositional-defiant disorder, and illicit drug use. His parents suspected IV drug use but the patient denied it. He had two recent suicide attempts with a benzodiazepine overdose and laceration of his right wrist. He was currently taking no medications.

The patient was transported to a local hospital emergency department. At arrival, he was confused and agitated, had severe swelling of the lips and tongue, and had marked cyanosis of his hands and feet. His initial blood pressure could not be determined but he did have palpable femoral pulses. He received endotracheal intubation and a normal saline IV bolus. Dopamine 2.5 [micro]g/kg/min was initiated and was increased to 5 [micro]g/kg/min after 10 minutes. Following this, blood pressure was 138/85 mmHg and pulse was 118 beats/min. Physical examination showed an adolescent male who weighed about 70 kg. His skin was cool and diaphoretic. He had normal breath sounds and no abnormal heart sounds. His abdomen was soft and nontender. His right arm bad no swelling or blisters but he did have an area of ecchymosis with several pinpoint petechiae surrounding the puncture site. Initial laboratory results showed an elevation in white blood cell count (19,300/mm) and hemoconcentration (hemoglobin was 21.7 g/dL and hematocrit was 62.8). Platelets were low (52,000/mm). PT was 98.3 seconds and INR was 8.9. Arterial blood gases showed a pH of 7.38, PC[O.sub.2] 25 mm Hg, P[O.sub.2] of 566 mm Hg, and a bicarbonate of 14.3 mmol/L. Urinalysis revealed pinktinged urine with a specific gravity of 1.015 and 10 to 20 red blood cells per high powered field. Four vials of crotalidae polyvalent immune fab (ovine) antivenom were administered over one hour.

Three hours after the venom injection, he had received 7 L of fluid and he had a blood pressure of 111/51mm Hg and a pulse of 78 beats/min. Physical examination was remarkable for epistaxis, minimally reactive pupils, coffee-ground emesis, and he was incontinent with melena. Chest x-ray and computed tomography of the head were normal. Creatine kinase was normal and cardiac enzymes were negative. Fibrinogen level was decreased at 118 mg/dL, fibrin split products were elevated at greater than 40 [micro]g/mL, and D-dimer was normal.

Due to the active gastrointestinal bleeding, 2 U of fresh frozen plasma and 6 U of platelets were administered. During the first 24 hours, the patient received a total of 18 vials of crotalidae polyvalent immune fab (ovine). He was kept sedated and paralyzed using lorazepam, morphine, and vecuronium. His coagulation panel, platelets, and fibrinogen level all returned within normal range by his 48th hour of admission. The local minimal reaction in the right antecubital fossa showed no signs of necrosis and resolved after several days. Sedation was slowly weaned off and the patient extubated himself on the third day. After psychiatric consultation, he was transferred five days after admission to a psychiatric facility. No additional complications were noted.

Discussion

Patients with suicidal ideation have intentionally injected many unusual substances intravenously (IV) including insecticide, (1) bleach, (2) mercury, (3) lamp oil, (4) cyanide and arsenic. (5) The self-injection of snake venom with a syringe by suicidal patients is uncommon but not unique. Two separate case reports described adult men who died after injecting venom from African snakes into SC tissue. (6-7) The only previously published report of IV self-injection of rattlesnake venom presented an adult man who injected venom milked from an eastern diamondback rattlesnake (Crotalus adamanteus). (8) He rapidly lost consciousness and then developed hematemesis, gross hematuria, melena, and bleeding from the injection site. He also had severe hematological abnormalities which resolved after 15 vials of antivenin (crotalidae) polyvalent (equine origin), and he survived.

Rattlesnakes inject venom through hollow fangs usually into the skin and SC tissue of their victims. (9) This causes the severe local reaction of swelling, pain, ecchymosis, and blisters near the bite site. Rarely, a fang penetrates a superficial vein causing both SC and IV envenomation. (10) Reports of at least 5 patients with suspected IV envenomation by rattlesnakes have been published. (10-12) All these patients developed severe systemic symptoms with only minor or moderate local reactions to the bites. Although all were treated with antivenin (crotalidae) polyvalent (equine origin), two died. (11-12) The others were discharged within a few days. Reports of IV envenomation usually note immediate (within a few minutes) findings of vomiting, swelling of lips and face, coma, and hypotension. Over the next few hours, these patients develop bleeding from several sites, increased PTT, decreased platelet count, generalized fasciculations, and fecal incontinence.

Our patient had minimal local findings around the injection site, but had severe systemic effects. This suggests that the patient did indeed inject the venom IV rather than SC or IM. In addition, our patient had immediate vomiting, swelling of the lips, decreased sensorium, and hypotension. He developed gastrointestinal bleeding, gross hematuria, fecal incontinence, and severe hematological abnormalities. However, our patient was unique in that he was an adolescent, the venom was probably from a western diamondback rattlesnake, and he was treated with crotalidae polyvalent immune fab (ovine) antivenom. This antivenom has only been commercially available in the USA since 2000.

Pit viper (including rattlesnake) bites with IV injection of venom probably occur more often than is reported. The physician should be aware that an IV envenomation of rattlesnake venom may not have the severe local reactions seen with the typical SC and IM envenomations. (9) Unfortunately, antivenom treatment is frequently determined by the amount of local reaction only. However, patients who develop the life-threatening symptoms of lip and tongue swelling, hypotension, and coma within a few minutes require antivenom regardless of the local reaction. (9) In addition, the hypotension usually responds to large amounts of IV saline solution. These patients usually undergo endotracheal intubation due to the initial facial and tongue swelling and coma. This swelling is also typically treated with steroids and antihistamines, but the effectiveness of this treatment in these patients is unknown.

References

1. Goldberg LH, Shupp D, Weitz HH, et al. Injection of household spray insecticide. Ann Emerg Med 1982;11:626-629.

2. Morgan DL. Intravenous injection of household bleach. Ann Emerg Med 1992;21:1394-1395.

3. Winker R, Schaffer AW, Konnaris C, et al. Health consequences of an intravenous injection of metallic mercury. Int Arch Occup Environ Health 2002;75:581-586.

4. Houben MH, Drent M, Jacobs JA, et al. Multiple organ dysfunction syndrome (MODS) after an intravenous injection of lamp oil (liquid paraffin). Intensive Care Med 1998;24:87-88.

5. DiNapoli J, Hall AH. Drake R, et al. Cyanide and arsenic poisoning by intravenous injection. Ann Emerg Med 1989;18:308-311.

6. Knight B, Barclay A, Mann R. Suicide by injection of snake venom. Forensic Science 1977;10:141-145.

7. Yadlowski JM, Tu AT, Garriott JC, et al. Suicide by snake venom injection. J Forensic Sciences 1980;25:760-764.

8. Weston MW. Lovelorn and snakebit. Hospital Practice 1986;21:140-143.

9. Gold BS, Dart RC, Barish RA. Bites of venomous snakes. N Engl J Med 2002;347:347-356.

10. Davidson TM. Intravenous rattlesnake envenomation. West J Med 1988;148:45-47.

11. Banner W, Russell F, Barton B, et al. Fatal rattlesnake bite in a child (abstract). Vet Hum Toxicol 1984;26:400.

12. Curry SC, Kraner JC, Kunkel DB, et al. Noninvasive vascular studies in management of rattlesnake envenomations to extremities. Ann Emerg Med 1985;14:1081-1084.</p> <pre> Happiness is spiritual, born of truth and love. It is unselfish; therefore it cannot exist alone, but requires all mankind to share it. --Mary Baker Eddy </pre> <p>David L. Morgan, MD, Hollie W. Blair, RPH, and Ryan P. Ramsey, MD

From the Central Texas Poison Center, and the Department of Emergency Medicine, Texas A & M University Health Sciences Center, Temple, TX.

Reprint requests to: David L. Morgan, MD, Department of Emergency Medicine, Scott and White Memorial Hospital, 2401 South 31st Street, Temple, TX 76508. Email: [e-mail]

Accepted December 2, 2005.

RELATED ARTICLE: Key Points

* Suicidal patients may inject unusual substances intravenously.

* Clinical findings of self-inflicted rattlesnake venom injected intravenously appear similar to those of the rare intravenous (IV) envenomation from a rattlesnake bite.

* IV envenomation of rattlesnake venom causes immediate vomiting, coma, hypotension, and swelling of the face, followed by severe hematological abnormalities and bleeding.

* Antivenom administration should focus on the systemic findings, not on the local reaction.