|Year : 2019 | Volume
| Issue : 2 | Page : 174-179
Role of prazosin in management of scorpion sting in pediatrics: a comparative study
Asmaa H Shoreit, Azza A Eltayeb, Samira S Ali
Pediatrics Department, Faculty of Medicine, Assiut University, Egypt
|Date of Submission||22-Feb-2018|
|Date of Acceptance||20-Mar-2019|
|Date of Web Publication||9-Jul-2019|
Samira S Ali
Pediatrics Hospital, Faculty of Medicine, Assiut University, Assiut
Source of Support: None, Conflict of Interest: None
Scorpion stings represent an important and serious public health problem worldwide owing to their high incidence and potentially severe and often fatal clinical manifestations. Children are at greater risk of developing severe cardiac, respiratory, and neurological complications owing to lesser body surface area. Prazosin, a postsynaptic alpha blocker, is an effective drug in the treatment of serious scorpion envenomation with significant sympathetic symptoms.
Aim of the study
To study the role of prazosin in the management of scorpion envenomation in children at Assuit University Children Hospital.
Patients and methods
The study included 60 patients with scorpion stings admitted to Assuit University Children's Hospital from November 2016 to November 2017. Their ages ranged from 1 to 18 years. Patients were randomized into two groups: group A underwent conventional therapy and prazosin and group B underwent conventional therapy.
Our results showed that addition of prazosin to antivenom induced earlier clinical recovery than in cases treated with conventional therapy. Administration of prazosin is one of the most useful strategies to reduce mortality in scorpion envenomation. A total of 60 cases of scorpion envenomation were observed during the study time period. Male children predominated over female.
Scorpion sting envenomation is an acute life-threatening emergency, and recovery from scorpion sting is hastened by simultaneous administration of scorpion antivenom plus prazosin compared with antivenom alone.
Keywords: antivenom, prazosin, scorpion sting
|How to cite this article:|
Shoreit AH, Eltayeb AA, Ali SS. Role of prazosin in management of scorpion sting in pediatrics: a comparative study. J Curr Med Res Pract 2019;4:174-9
|How to cite this URL:|
Shoreit AH, Eltayeb AA, Ali SS. Role of prazosin in management of scorpion sting in pediatrics: a comparative study. J Curr Med Res Pract [serial online] 2019 [cited 2020 Feb 19];4:174-9. Available from: http://www.jcmrp.eg.net/text.asp?2019/4/2/174/262397
| Introduction|| |
Scorpions are a group of arthropods belonging to the family Buthidae, which are potentially dangerous to humans. Owing to their high incidence, scorpion envenomation is an important and serious health problem in many tropical and subtropical countries with a potential of severe and often fatal clinical manifestations among children. Envenomation of children can cause multiple organ failure and death.
Children are at greater risk of developing severe envenomation like cardiac, respiratory, and neurological complications as compared with the adults. The clinical manifestations of scorpion envenomation are vomiting, profuse sweating, cold extremities, pulmonary edema, and death. The deaths in scorpion sting envenomation are attributed to cardiopulmonary complications like myocarditis and acute pulmonary edema.
Pulmonary edema is a very common manifestation of scorpion sting envenomation in children. Overall, 40% of fatalities have been reported owing to refractory pulmonary edema. As the mortality rates owing to scorpion sting envenomation are as high as this, new treatment modalities have begun to be discussed.
Prazosin, a postsynaptic alpha-1 blocker, counteracts the effects of excessive catecholamines and arrests the development of severe systemic features. It has been found to be an effective drug for scorpion sting envenomation, and it has reduced the mortality rate to 1% as compared with a 30% mortality rate in the pre-prazosin period. The present study was done to observe the outcome and the efficacy of prazosin in scorpion sting envenomation in children who were admitted at tertiary care center.
| Patients and Methods|| |
The study was approved by the ethical committee of Assuit faculty of medicine at Assuit University. A written informed consent was obtained from parents of the enrolled cases. The study was conducted at Emergency Unit, Intermediate Care Unit, and Pediatric intensive care unit at Assuit University Children's Hospital.
The study included 60 patients with scorpion stings admitted to Assuit University Children's Hospital from November 2016 to November 2017. Their ages ranged from 1 to 18 years.
All cases with scorpion sting were admitted to Assuit University Children's Hospital.
All other envenomation cases or poisoning were excluded.
Dose and administration
Prazosin, per oral, 30 μg/kg/dose was administered. In case of vomiting or unconsciousness, prazosin was administered through nasogastric tube with securing of the airway. Blood pressure, pulse rate, respiration rate, and oxygen saturation were monitored every 30 min for 3 h, every hour for next 6 h, and later every 4 h till improvement. Prazosin was repeated in the same dose at the end of 3 h according to clinical response and later every 6 h till extremities were warm and dry and peripheral veins were visible easily. It should not be given as prophylaxis in children when pain is the only symptom. The patient should be kept in a lying posture for approximately 3 h (even while examining the case) to prevent first-dose phenomenon (hypotension) from prazosin.
| Results|| |
The study included 60 cases with scorpion sting, comprising 35 males and 25 females. Their ages ranged from 1 to 18 years. Cases were divided into two groups, i.e. group A and group B, regarding prazosin administration.
Recorded data about laboratory and imaging study of cases with scorpion stings on admission showed that no abnormalities were detected in complete blood count and kidney function and impaired values of creatine kinase level, blood gases, serum electrolyte, and ECG, with no significant difference between group A and group B [Table 1], [Table 2],[Table 3] and [Figure 1], [Figure 2], [Figure 3].
|Table 2: Variables of symptoms and signs of case with scorpion stings among the studied cases at the time of admission, at 3-h follow-up, and after 24 h of admission|
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|Table 3: Recorded data about outcome of cases with scorpion stings according to prazosin administration|
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| Discussion|| |
Scorpion envenomation is an important public health problem in many tropical and subtropical countries. Envenomation by scorpions can result in a wide range of clinical effects including cardiotoxicity, neurotoxicity, and respiratory dysfunction. Prazosin, a competitive postsynaptic alpha-1, adrenergic receptor antagonist, should be the first line of management after antivenom therapy. Prazosin by blocking alpha receptors corrects the abnormal hemodynamic and metabolic effects of circulating catecholamines.
In our study, male children predominated over females, where 35 (58.3%) cases were males and 25 (41.7%) cases were females. Arivoli and Ganesh found that the numbers of stings in boys were higher than in girls, with 61.7% in male and 38.3% in female.
In our study, the distribution of age was more common in the age group 1–6 years, with 33 (21.7%) cases. This may be related to the careless behavior such as walking barefoot, lifting up stones, and putting on clothes and shoes without checking them. Accordingly, Saminathan et al.showed the percentage of cases among age group in 1–3 years was 42%, 4–6 years was 34%, 7–9 years was 12%, and older than 10 years was 12%.
Regarding the geographical distribution, 53 (88.3%) cases were from rural areas and seven (11.7%) cases from urban areas. Accordingly, Konca et al. had similar study that showed the rural areas were presented in 28 (84.8%) cases and the urban areas were presented in five (15.2%) scorpion sting cases.
Regarding the site of sting in our study, 22 (36.7%) cases were stung in the upper limbs, whereas 31 (51.7%) cases were stung in the lower limbs and seven (11.6%) cases were stung in the head, neck, and trunk. Extremities were the most common part affected by scorpion sting in our study, which is also reported in other studies. People are stung by scorpions on their extremities because it is the part that is presented most commonly to the scorpion. Moreover, the incidence depends on the agricultural habits in rural areas such as wearing sandals, walking barefoot, putting on shoes without preshaking, and lifting up stones in a careless manner.
In our study, the symptoms and signs among the studied cases at the time of admission showed that all patients have pain at the site of sting in 60 (100%) cases, vomiting in 58 (96.7%) cases, cold extremities in 60 (100%) cases, salivation in 34 (56.7%) cases, swelling in 18 (30%) cases, difficult of breathing in six (10%) cases, sweating in 34 (56.7%) cases, priapism in 10 (16.7%) cases, tachycardia in 15 cases, and bradycardia in three (5%) cases. Accordingly Ganesh and Kumaravel showed similar study results, where pain was present at the site of sting in 66 (100%) cases, salivation in 26 (36%) cases, vomiting in 34 (47%) cases, dyspnea in 23 (32%) cases, swelling in 28 (39%) cases, and diaphoresis in 57 (79%) cases. Moreover, Arivoli and Ganesh presented that pain at the site of sting was seen in 79.4%, swelling in 10.2%, salivation in 36.7%, vomiting in 41.1%, priapism in 30.9%, diaphoresis in 70.5%, cold extremities in 83.8%, hypotension in 66%, bradycardia in 10%, and tachycardia in 55%.
The systemic manifestations are owing to the release of neurotransmitters in response to the actions of the toxin on sodium channels causing an adrenergic or cholinergic syndrome leading to a range of clinical pictures according to the species of scorpion. The unopposed effects of alpha-receptor stimulation can lead to suppression of insulin secretion causing hyperglycemia and liberation of free radicals causing injury to the myocardium. Clinical features can be localized (pain, hyperemia, edema, and numbness) and systemic effects (hyperthermia, nausea and vomiting, tachycardia, shivering). Severe scorpion envenomation can result in cardiovascular, pulmonary, and neurological manifestations and may be life-threatening owing to myocardial dysfunction, shock, pulmonary edema, or hypertensive encephalopathy.
Regarding the manifestations, after 3 h, there was improvement of some clinical symptoms and signs. Vomiting was seen in 16.7% in group A compared with 46.7% in group B, with significant P value of 0.026. Moreover, cold extremities were seen in 30.0% in group A compared with 80% in group B, with significance P value less than 0.001. Moreover, sweating was seen in 13.3% in group A compared with 60.0% in group B, with significant P value of 0.001, and hypothermia was seen in 16.7% in group A compared with 46.7% in group B, with significant P value of 0.026. After 3 h, three new cases developed pulmonary edema in group B. Accordingly Khalaf et al., showed that rewarming of extremities after prazosin occurred after 7.2 ± 3.26 h in group A and 12.75 ± 5.10 h in group B.
In our study, the symptoms and signs after 24 h of admission showed improvement of tachycardia seen in 16.7% in group A compared with 43.3% in group B, with significant P value of 0.049 and also arrhythmia was seen in 6.7% in group A compared with 26.7% in group B, with significant P value of 0.038. Our results showed that addition of prazosin to antivenom induced earlier clinical recovery than in cases treated with conventional therapy only. Most of them needed only one dose of prazosin for clinical recovery. These results were in agreement with other studies, such as by Khalaf et al. who showed that normalization of heart rate occurred after 20.64 ± 9.49 h in group A and 46.5 ± 12.29 h in group B.
Regarding laboratory and imaging study of cases with scorpion stings on admission, it showed that no abnormalities were detected in complete blood count and kidney function and there were impaired values of creatine kinase level, blood gases, serum electrolyte, and ECG, with no significance difference between group A and group B. These results are in agreement with Arivoli and Ganesh who showed that abnormal results in chest radiography (pulmonary edema) were found in six (8.8%) cases and abnormal ECG sinus tachycardia was found in 42 (61.7%) cases with use of prazosin.
The present study showed that the complications among the studied cases at time of admission were cardiogenic shock in 10 (16.7%) cases, hypovolemic shock in three (5%) cases, pulmonary edema in six (10%) cases, and myocarditis in 11 (18.3%) cases, with no significance difference between group A and group B. Accordingly, Bosnak et al. had similar results, with pulmonary edema in five (9.6%) cases, hypotension in two (3.8%) cases, and tachycardia in 19 (36.5%) cases. Moreover, Bawaskar showed that in patients with severe envenomation by Mesobuthus tamulus admitted at Mahad, pulmonary edema was seen in 27% and tachycardia with hypotension in 18%. In addition, Rathod and Tamba had similar study who showed that pulmonary edema was found in three (25%) cases in group B only.
In our study, the complications among the studied cases at 3-h follow-up showed that three cases developed pulmonary edema and one case developed cardiogenic shock in group B with no deterioration in group A.
After 24 h of admission, the patients showed improvement of pulmonary edema in 6.7% in group A compared with 16.7% in group B, with no significance difference between group A and group B. Bawaskar and Bawaskar concluded that scorpion antivenom is no more effective at alleviating or reversing the cardiovascular effects of scorpion venom in severe cases when compared with prazosin, which prevents and reverses the cardiovascular manifestations of severe scorpion envenomation. Accordingly, Khalaf et al. showed that normalization of blood pressure occurred after 12.48 ± 2.4 h in group A and 28.5 ± 8.62 h in group B. Moreover, Natu et al. performed a similar study which showed that patients with prazosin showed early recovery than in the other group.
After 48 h of admission, the patients showed improvement of cardiogenic shock in 6.7% in group A compared with 10% in group B, with no significant difference between group A and group B. Moreover, improvement of pulmonary edema was seen in 3.3% in group A compared with 13.3% in group B with no significant difference between group A and group B. Accordingly, Peker et al. showed that the patient symptoms had fully resolved within 36 h. Respiratory difficulty had disappeared, and the patients were discharged 48 h after admission.
Regarding the outcome, cases with scorpion stings showed that five (8.3%) cases died [one (3.3%) case in group A and four (13.3%) cases in group B] and 55 (91.7%) cases improved [29 (96.7%) cases in group A and 26 (86.7%) cases in group B]. Prazosin has been found to improve scorpion sting envenomation. Accordingly, Bahloul et al. reported that the mortality rate was reduced to 1% as compared with a 30% mortality rate in the pre-prazosin period. In addition, Koseoglu showed that impressive reductions in mortality from Mesobuthus tamulus sting have also been observed with the use of prazosin, from 26% in 1961 to 6% in 1980, and less than 1% in 2006. In addition, Rathod and Tamba, 2013, performed a similar study with recovery rate of 50% in group A and 25.0% in group B.
Regarding the need for respiratory support, 9 cases (15%) needed mechanical ventilation, with 4 cases (13.3%) in group A and 5 cases (16.7%) in group B. Accordingly, Arivoli and Ganesh showed that 14.7% needed CPAP/MV with use of prazosin.
In our study, the duration of hospital stay was less in group A in comparison with group B. Patients in group A showed early recovery than in the group B. This is in accordance with Arivoli and Ganesh who found that 82.3% stayed for < 3 days and 17.6% stayed for > 3–5 days with the use of prazosin. Moreover, Rathod andTambashowed that the time for recovery was better in cases treated with prazosin.
| Conclusion|| |
Our results showed that addition of prazosin to antivenom induced earlier clinical recovery than in cases treated with conventional therapy only. Most of the patient needed only one dose of prazosin for clinical recovery.
The time interval between sting and arrival to health care should be recorded.
Duration between the time of sting and prazosin administration should be recorded.
Comparison between three group (antivenom only, prazosin only, and antivenom and prazosin) should be done.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3]
[Table 1], [Table 2], [Table 3]