Life threatening scorpion sting on adult complicated by: acute toxic myocarditis, cardiogenic shock, pulmonary edema, acute kidney injury and toxic hepatitis: a case report

Abstract

Background

Occurrence of life-threatening scorpion sting in adults is a rare entity compared with children. Different cases of organ failure following scorpion sting have been reported but complications, such as acute toxic myocarditis, cardiogenic shock, pulmonary edema, acute kidney injury and toxic hepatitis occurring simultaneously in adult patients is exceedingly rare with no prior documented similar report. This case report explores the unique presentation of these complications occurring simultaneously and their management in resource limited setting.

Case presentation

A 31-year-old Eritrean female came to our emergency room with severe respiratory distress, persistent retching, drenching sweating, generalized pain and unrecordable blood pressure 12 hours after scorpion sting. Electrocardiography revealed signs of diffuse acute myocarditis. The diagnosis of cardiogenic shock and pulmonary edema owing to scorpion sting envenomation was made. The patient also developed acute kidney injury and toxic hepatitis. She recovered well after 10 days of hospital stay and further follow-up, with supportive management and scorpion antivenom. To date, over a period of more than 2 years the patient has no new complaint or complication.

Conclusion

This case report highlights the clinical novelty of multiorgan failure following scorpion sting in adults. The unique presentation of acute toxic myocarditis, cardiogenic shock, pulmonary edema, acute kidney injury and toxic hepatitis in a 31-year-old female underscores the possibility of scorpion sting causing such life threatening envenomation after delayed presentation. This case contributes to the understanding of atypical presentations of scorpion sting in adults.

Background

Scorpions are group of arthropods belonging to the family Buthidae, which are potentially dangerous to humans [1, 2]. Scorpion stings are primarily due to accidental contact with scorpion as scorpions usually try to escape from humans. Scorpion sting can pose a life threatening acute medical emergency and is a neglected public health problem in tropical and subtropical countries, especially in North Africa, Middle East, Latin America, and India [3].

Most scorpion envenomation’s only cause immediate local pain [4]. Clinical and experimental studies have reported that scorpion venom is distributed throughout the body very rapidly; thus, the time between scorpion sting and antivenom management is of critical importance [5]. The clinical signs depend on the dose of poison, patient age, season, and the time between scorpion sting and admittance to hospital [6]. Children are at greater risk of developing severe envenomation, such as cardiac, respiratory, and neurological complications, compared with the adults owing to their lower body surface area [4, 7]. Mortality due to scorpion sting is associated with cardiac dysfunction and pulmonary edema [6]. Myocarditis associated with scorpion envenomation is usually reported in children [8]. Here we report a very rare occurrence with no prior documented similar report, that can contribute to the understanding of atypical complication of scorpion sting envenomation, in which a scorpion sting was complicated by myocarditis, cardiogenic shock, pulmonary edema, acute kidney injury, and toxic hepatitis in an adult female, after which she fully recovered.

Case presentation

This 31-year-old Eritrean female patient presented to our emergency department on 1 June 2022 after being stung by a scorpion on her right toe while she was walking barefoot preparing dinner in her compound 12 hours before emergency arrival. The patient immediately noticed the scorpion and it was killed by her family. Immediately after the stung she experienced extreme local pain, which became generalized involving the whole body accompanied by paresthesia. This was followed by persistent vomiting and profuse sweating about 1 hour after of the sting. She later started to have progressive shortness of breath. Patient had no personal or family history of cardiac disease or known chronic illness. She had no history of consumption of alcohol, tobacco, or illicit drugs. She is a mother of two, housewife who cannot read or write, and lives in a small arid village at the outskirt of Teseney town, in a hut. Her husband is a farmer and she occasionally helps him at the farm where their income is mainly from. No prior similar incident or sting was reported by the patient. No history of medication intake nor intervention was done for other medical conditions prior to the envenomation. Presentation to our hospital was delayed as seriousness of her condition was initially overlooked in addition to transport unavailability on that rainy night. On arrival to the emergency department, she was agitated in severe respiratory distress, persistently retching, and drenched sweating all over her body. Vital signs measured revealed unrecordable blood pressure, pulse rate of 140 beats/minute, respiratory rate of 56 breaths/minute, Spo₂ of 90% in room air, and temperature of 37.1 °C. Chest examination revealed bilateral decreased air entry with fine basal crepitation’s. There was no bronchial breath sound or wheezing and chest was resonant to percussion throughout. On cardiovascular system examination jugular venous pressure was elevated and measured 4 cm above the sternal angle measured at 30°. S1 and S2 was well heard, no murmur or gallops were observed. There was no peripheral edema. Peripheral pulses were faintly palpable in their respective areas and had pale, noncyanotic icy cold extremity with skin moistened in sweat. There was no palpable enlarged organ or tenderness on abdominal examination. There was no swelling, erythema, or other local changes on examination of the area that was stung. Central nervous system exam revealed confused patient with Glasgow coma score (GCS) of 14/15, no sensory or motor deficit, normo-reflexia, with intact cranial nerve examination. Meningeal signs were negative. With the assessment of pulmonary edema and cardiogenic shock owing to grade IV scorpion sting envenomation, the patient was supported with oxygen given via nonrebreather mask from oxygen cylinder. As there were only four beds in the emergency room and no special care unit in the setup she was transferred to general medical ward after infiltration of the stung area with 3 ml of lidocaine hydrochloride injection USP 2% while receiving two vials of scorpion antivenom dissolved in 50 ml 5% dextrose solution over 30 minutes. Diazepam at 10 mg was intravenously administered to manage the agitation. Patient was then started on dopamine infusion in the ward. Chest radiography showed bilateral bat wing shaped interstitial and alveolar infiltrates compatible with pulmonary edema and cardiothoracic ratio of 47%. Electrocardiography (ECG) done on day of admission showed extreme tachycardia,165 beats per minute with ST segment depression on leads II, III, aVF, and V1–V6 and ST segment elevation on leads aVR and aVL(Fig. 1). At 5 hours after admission patient became febrile with temperature of 38.1 °C, which was being managed with warm compresses. Complete blood count showed white blood cell (WBC) count of 5200/μL, platelet of 213,000/μL, and hemoglobin of 13.1 g/dL, and blood film test was negative for malaria parasites. The patient was catheterized and had urine output of 90 ml/6 hours (0.3 ml/kg/hour). Blood chemistry done on 2nd day of admission showed mild elevation in creatinine, alanine transaminase, aspartate transaminase, and uric acid (Table 1) indicating acute kidney injury and acute toxic hepatitis despite initially being normal. From 2nd day of admission, she regained full consciousness without any neurological abnormality. The respiratory rate, pulse rate, and oxygen saturation were also improving steadily and dopamine was discontinued on 3rd day of admission after the patient started to maintain blood pressure above 90/60 and urine output of 600 ml/24 hours (0.5 ml/kg/hour). Furosemide at 20 mg administered intravenously twice per day was then initiated increasing the urine output to 0.9 ml/kg/hour. Chest X-ray revealed marked improvement of pulmonary edema (Fig. 2). ECG repeated on 3rd day of admission revealed improved ST segment changes and tachycardia compared with the previous ECG and further improved on ECG done on 7th day of admission (Fig. 3). After gradual weaning from oxygen support, the patient’s condition improved over hospital stay of 10 days’ and furosemide was discontinued after 10th day of follow-up. Follow-up assessment on 10th day revealed a fully recovered walking, neurologically fit patient who was doing her previous daily chores without any difficulty. Blood chemistry also showed normalization of previously elevated markers (Table 1). Monthly follow-up for 1 year thereafter revealed a healthy adult female with no further complaints. To date the patient has no complaints or complications, and has been discharged from follow up after 3 monthly uneventful follow-ups for a year. Table 2 shows a of timeline of events and progression of the patient’s recovery (Table 2).

Fig. 1

Electrocardiography on day of admission showing 165 beats per minute with ST segment depression on leads II, III, aVF, and V1–V6 and ST segment elevation on leads aVR and aVL

Table 1 Serial blood chemistry of the patient

Fig. 2

Chest radiography on day 4 showing increased pulmonary vascular marking, improved pulmonary edema and normal cardiothoracic ratio

Fig. 3

Electrocardiography on 7th day of admission showing 104 beats per minute, ST segment normalization on leads I, III, V1, aVR, and aVL and improved ST segment depression on leads aVF and V2–V6

Table 2 Timeline of events and progression of the patient’s recovery

Discussion

Scorpion sting envenomation is an acute life threatening, time-limiting, and serious public health medical emergency worldwide [7]. Scorpion stings cause envenomation ranging from local pain to severe cardiopulmonary distress and death. A prospective study undertaken in India to elucidate the clinical profile of 82 adult patients with scorpion sting reported the percentages of clinical features among the patients as: pain (87.5%), sweating (81.25%), tingling and numbness (77.5%), tachycardia (75%), cold clammy extremities (62.5%), hypertension (55%), restlessness (52.5%), swelling at the site of sting (45%), pulmonary edema (30%), shortness of breath (35%), hypotension (25%), vomiting (18.75%), altered sensorium (10%), bradycardia (7.5%), and death (3.75%) [2]. A retrospective study done in Morocco among 163 children with scorpion sting reported the percentages of clinical features among the patients as: pain (81.6%), vomiting (73%), sweating (63.8%), hyperemia(55.8%), priapism (50% of the males; 51 out of the 102 males), tachycardia (42.9%), restlessness (36.2%), shivering (32.2%), tachypnea (30.7%), fever (28.8%), collapse (26.4%), bradypnea (25.2%), confusion (22.7%), rhinorrhea (17.2%), acute pulmonary edema (15.3%), hypersialorrhea (11.7%), hypothermia (10.4%), lacrimation (10.4%), convulsion (8%), bradycardia (8%), abdominal pain (6.1%), coma (5.5%), myosis (3.1%), and diarrhea (1.8%) [9].

Scorpion venom contains multiple mixtures, of which the neurotoxin part is of greatest importance. The toxin acts by opening sodium channels at presynaptic nerve terminals and inhibiting calcium dependent potassium channels [7]. Activation of parasympathetic nervous system leads to a cholinergic (or muscarinic) syndrome manifested by hypersecretion syndrome. This syndrome is usually short lived and shows that there is circulating scorpion venom, which can be neutralized by scorpion antivenom before it is masked later by overstimulation of the sympathetic system, which increases blood levels of catecholamine’s, resulting in a characteristic “adrenergic (autonomic) storm” [10]. Thus, the time from the sting to arrival at the hospital is a factor in patient’s presentation [8]. Initially our patient developed vomiting and sweating as a manifestation of parasympathetic activation. Antivenom administration at this point might have mitigated the progression of symptoms to sympathetic activation manifested as tachycardia, hyperthermia, tachypnea, and agitation in our patient. Clinical pictures from studies have shown that patients initially develop hypotension and bradycardia as part of cholinergic syndrome, which later becomes overwhelmed by hypertension and tachycardia owing to adrenergic storm, before they progress to hypotension and/or pulmonary edema which shows the severity of the sting [6]. Owing to delayed presentation our patient had passed the sympathetic hypertensive episode, then presented with unrecordable blood pressure and pulmonary edema. Hyperthermia was managed with warm compresses by nursing staff and family and it only lasted for 1 day. Hyperthermia is more commonly seen in children than in adults. Its prompt management to control body temperature is essential to prevent dissociation of temperature sensitive enzymes and progression to multiorgan failure and death [11].

Myocarditis is one the most important and rare features of scorpion envenomation [8, 12]. It is caused by a complex interplay of hemodynamic, metabolic, and myocardial variables leading to myocardial dysfunction. The most common ECG changes were ST changes, sinus tachycardia, atrial ectopic beat, bradycardia, and ventricular ectopic beat as reported by Al et al. [13] A systematic review by Fereidooni et al. also reported that the most common ECG findings were sinus tachycardia (82%) followed by ST-T changes (64.6%) [8]. Our patient showed extreme tachycardia with ST segment changes as signs of diffuse myocarditis. In addition to this ECG findings, our patient also developed cardiogenic shock and pulmonary edema as a result of the severe cardiac dysfunction.

Inotropes as well as diuretics are used to treat in almost all cardiogenic shock and pulmonary edema associated with scorpion sting, as was shown in a systematic review of 703 cases from 30 case reports and 34 case series. Dobutamine was the most widely used [8]. We used dopamine to manage our patient, an acceptable alternative as dobutamine was out of stock. With proper supportive management, in most uncomplicated cases, clinical improvement starts soon and regression of pulmonary edema and shock is expected to occur within 48 to 96 hours [8]. Our patient started to improve after 72 hours of admission with dopamine infusion. We continued with diuretics until follow-up. Similar to our case report, different case reports have shown that total pre-envenomation condition of the patient returned with such supportive management [8, 14].

The patient also developed oligo uric acute kidney injury. Several pathophysiology mechanisms have been proposed to acute kidney injury in scorpion sting. Our patient had persistent vomiting and profuse sweating, which could lead to hypovolemia in addition to the cardiogenic shock and nephrotoxic nature of the venom to cause AKI similar from other reported cases [4, 15]. Her kidney function returned to normal levels during her hospital stay.

The patient’s liver enzymes increased during the patient’s initial course. Elevated liver enzymes show the degree of hepatocellular damage and might be a prognostic tool [16, 17]. Cytotoxic effect of the venom, increased catecholamine, cytokines, and inflammatory mediators are proposed mechanism [18]. Histopathologic changes in the liver and liver enzyme elevation are statistically dependent to the time after envenomation as was experimented by injecting rats with scorpion venom [19]. Similarly, our patient developed elevated liver enzymes, which was linked to post envenomation time and later started to normalize during her hospital stay and follow-up, as in other cases [18].

Different cases of organ failure following scorpion sting have been reported but our case highlights the extremely rare occurrence of acute toxic myocarditis, cardiogenic shock, pulmonary edema, acute kidney injury, and toxic hepatitis, all in one adult patient. A table of different case reports has been added to give a glance of different presentations, complications, and management of scorpion sting (Table 3). Our case also shows the recovery of such patient, despite the challenge of managing such intensive care needy patient in resource limited setting. Availability of high dependency unit or cardiac care unit, echocardiography, cardiac MRI, cardiac markers, arterial blood gases, and prazosin would have had positive value in the management.

Table 3 Different case reports of organ failure following scorpion sting

Conclusion

Our case report underscores multiorgan failure from scorpion sting. Different cases of organ failure following scorpion sting have been reported but our case adds to existing literature that scorpion sting can cause acute toxic myocarditis, cardiogenic shock, pulmonary edema, acute kidney injury, and toxic hepatitis, all in one adult patient with no prior documented similar report. This very unusual manifestation happened after delayed hospital visit following a sting, which necessitated prolonged hospitalization.