Severe Scorpion Envenomation Research Articles

Hyperglycemia is a risk factor for high-grade envenomations after European viper bites (Vipera spp.) in children

Context: Hyperglycemia has been described in severe scorpion envenomation, we wanted to analyze if it was applicable to viper bites in children. Aim: To describe clinical, biological, and therapeutic characteristics of 83 children bitten by European viper (Vipera spp.) and to confirm that hyperglycemia is a risk factor for high-grade envenomation. Material and methods: A retrospective study was conducted between 2001 and 2014 in the pediatric emergency department of a tertiary level children’s hospital. Collected data were: age and sex of children; day and time of admission; day, time and circumstances of the accident; snake identification; bite location; envenomation severity; presence of fang marks; prehospital care; laboratory abnormalities, use of specific immunotherapy, associated treatments; length of stay; hospital course. Results: Eighty-three children were included (62 boys, 21 girls). The mean age was 7.4 ± 3.9 years. Bites were most often located on the lower extremities (66%). The classification of envenomation was: 83% low grade (absent or minor envenomation) and 17% high grade (moderate to severe envenomation). All high-grade envenomations received specific immunotherapy (ViperfavTM, (Aventis Pasteur, MSD, Lyon, France). Being bitten on an upper extremity (odds ratio [OR] 51.1 95% class interval [CI] [6.1–424], p < 0.0001), during the afternoon (OR 13.4 95% CI [1.7–107.9], p = 0.015), feeling violent pain (OR 4.2 95% CI [1.1–16.5], p = 0.023), and high initial plasma glucose level (6.5 ± 1.7 mmol/L versus 5.0 ± 0.9 mmol/L, p = 0.027) were associated with a significant risk of high-grade envenomation. Conclusion: We have confirmed a potential link between initial hyperglycemia and the risk of progression to high-grade envenomation as well as its association with other published predictive factors.

The role of dorsomedial hypotalamus ionotropic glutamate receptors in the hypertensive and tachycardic responses evoked by Tityustoxin intracerebroventricular injection

The scorpion envenoming syndrome is an important worldwide public health problem due to its high incidence and potential severity of symptoms. Some studies address the high sensitivity of the central nervous system to this toxin action. It is known that cardiorespiratory manifestations involve the activation of the autonomic nervous system. However, the origin of this modulation remains unclear. Considering the important participation of the dorsomedial hypotalamus (DMH) in the cardiovascular responses during emergencial situations, the aim of this work is to investigate the involvement of the DMH on cardiovascular responses induced by intracerebroventricular (icv) injection of Tityustoxin (TsTX, a α-type toxin extracted from the Tityus serrulatus scorpion venom). Urethane-anaesthetized male Wistar rats (n=30) were treated with PBS, muscimol or ionotropic glutamate receptor antagonists, bilaterally in DMH and later, with an icv injection of TsTX, or treated only with PBS in both regions. TsTX evoked a marked increase in mean arterial pressure and heart rate in all control rats. Interestingly, injection of muscimol, a GABAA receptor agonist, did not change the pressor and tachycardic responses evoked by TsTX. Remarkably, the injection ionotropic glutamate receptors antagonists in DMH abolished the pressor and the tachycardic response evoked by TsTX. Our data suggest that the central circuit recruited by TsTX, whose activation results in an array of physiological and behavioral alterations, depend on the activation of DMH ionotropic glutamate receptors. Moreover, our data provide new insights on the central mechanisms involved in the development of symptoms in the severe scorpion envenomation syndrome.

Impact of Hydrocortisone Hemisuccinate Use on Outcome of Severe Scorpion-Envenomed Adult Patients

The aim of this study is to analyze if the infusion of hydrocortisone hemisuccinate improve outcome in severe scorpion-envenomated adult patients admitted to intensive care unit (ICU). Pairwise retrospective case-control study with 1:1 matching was designed. Patients were defined as cases when they received hydrocortisone hemisuccinate (as alone steroids) during hospitalization and as controls when they did not received any steroids. Patients were matched according to age, severity factors at admission represented by the presence of pulmonary edema and grades of severity of scorpion envenomation, and scorpion antivenom administration. Eighty-four patients were included as follows: 42 patients in the cases group and 42 patients in the control group. The mean age (±SD) was 40±21 years, ranging from 16 to 90 years. Moreover, 67 (80%) patients have a systemic inflammatory response syndrome on ICU admission. The comparison between cases group and control group showed that age is not significantly different. There were the same proportions of patients with pulmonary edema in 2 groups. Moreover, 23 (54%) patients in case group and 23 (54%) in the control group received scorpion antivenom (P>0.05). The mean temperature on admission was also not significantly different. The presence of systemic inflammatory response syndrome was again not significantly different between 2 groups. The comparison of outcome of the 2 groups showed that the use of mechanical ventilation and its duration, the ICU stay length, and ICU mortality was not significantly different between the 2 groups. Although our study has some limitations, it confirms that the use of hydrocortisone hemisuccinate in severe scorpion-envenomed patients did not improve their outcome.

Sustained Ventricular Tachycardia and Cardiogenic Shock due to Scorpion Envenomation

We describe a case of severe scorpion envenomation in an adult patient, with the presence of very rapid sustained ventricular tachycardia followed by cardiogenic shock, which was reversed by scorpion antivenom administration. Scorpion venom causes cardiac changes that can lead to an environment favoring arrhythmogenesis.

Cardiac involvement and its complications about three cases of severe scorpion envenomation

For several decades, Morocco is confronted to medico-social problem of scorpion stings and envenomations. In 2009, epidemiological data established by the Poison Control Center recorded 29,816 stung patients, with an incidence of 1.1‰ and a fatality rate of 0.18%. The neurotoxins from scorpion venom are potent activators of the autonomic nervous system resulting a physiopathological disorder of vital systems. The most serious clinical manifestations are neurotoxic effects, pulmonary edema and cardiovascular distress. This present work reports the cases of three children (4 years and 6 months, 8 months and 15 days, 4 years), hospitalized in intensive care for an envenomation by Androctonus mauritanicus (the most fatal scorpion specie). The children presented cardiac dysfunction where pulmonary edema and state of shock were complications resultants. Two cases survived after supportive and symptomatic treatment based on dobutamine as primordial treatment in cardiovascular and pulmonary correction and other drugs. The third case died. The objective of this work was to detect the limit of the effectiveness of symptomatic treatment during a severe scorpion envenomation.

The Deciphered Genome of Mesobuthus martensii Uncovers the Resistance Mysteries of Scorpion to Its Own Venom and Toxins at the Ion Channel Level

ancestor (a species of fossil scorpion from Silurian to lower Devonian) [2]. From the fossils of the late Silurian period, scorpions were found to have developed and adapted their venomous systems [1]. Evolving over the past 400 million years, scorpion venoms contain a va riety of compounds, including the more or less potent and selective peptide toxins acting on the diverse and ubiquitous ion channel proteins. The latter are widely distributed in many systems, such as nervous, skeletal and cardiovascular in the scorpion’s prey (or predator). Basically, the severity of scorpion envenomation ranges from local pain and paresthesia to lethal cardiotoxicity and encephalopathy [3]. At present, it is a serious cause of mortality in several Latin countries, in South America, southern and western Asia, and Africa. The number of scorpion stings is estimated to be

Transactions of the Royal Society of Tropical Medicine and Hygiene

This paired case-control study examined the safety and efficacy of using hydrocortisone in children with severe scorpion envenomation requiring the intensive care unit (ICU). The study took place in Tunisia, which has an estimated 40,000 scorpion stings per year, with the most severe envenomations caused by the species Androctonus australis and Butus occitanus. The clinical symptoms and signs of scorpion envenomations are caused by massive catecholamine release, direct venom effects, and generalized inflammation. The authors postulate that steroids may reduce the proinflammatory effect of massive cytokine release after scorpion envenomation; however, this is the first study to directly investigate steroid use for scorpion envenomation in children. The investigators reviewed ICU records for a 13-year period and matched patients receiving steroids with control patients who did not receive steroids by age, severity factors, and scorpion antivenom administration. Primary outcome measures were ICU mortality rate, use of mechanical ventilation, duration of ICU stay, and laboratory analysis. A total of 685 children were admitted for scorpion stings, and 92 received steroids with hydrocortisone hemisuccinate (200–300 mg per 24 hours for 48 hours). The 2 groups had the following similar characteristics: 50% received the scorpion antivenom, 79% developed pulmonary edema or cardiogenic shock, and 66% required catecholamines for hemodynamic support. There was no significant difference in mortality rate (8%), the use of mechanical ventilation (35%), or duration of ICU stay (average 2.6 days) between the 2 groups. The steroid group had a higher rate of hyperglycemia and hypokalemia; however, there were no other significant laboratory differences. The investigators concluded that the prognosis of children with severe scorpion envenomation admitted to the ICU was not improved by the use of hydrocortisone. Limitations of the study include that is was a single-site investigation and potential changes in clinical management during the study period. (Trans R Soc Trop Med Hyg. 2013;107:349–355) M Bahloul, A Chaari, R Ammar, et al.

Brainstem Structures Are Primarily Affected in an Experimental Model of Severe Scorpion Envenomation

Severe scorpion envenoming (SSE) is more frequent in children and is characterized by systemic dysfunctions with a mortality rate of up to 9%. Recent evidence shows that the central nervous system (CNS) plays a key role in triggering the cascade of symptoms present in SSE. The age-dependent role of the CNS in SSE lethality may be summarized in 3 hypotheses: (1) the shown increased blood brain barrier permeability of infants to the toxins would especially and primarily compromise neurovegetative control areas, (2) the neurons within these areas have high affinity to the toxins, and (3) the neurovascular interaction is such that SSE metabolically compromises proper function of toxin-targeted areas. A pharmacological magnetic resonance imaging paradigm was used to evaluate localized hemodynamic changes in relative cerebral blood volume (rCBV) for 30 min after the injection of TsTX, the most lethal toxin from the venom of the Tityus serrulatus scorpion. The brainstem showed significant rCBV reduction 1 min after TsTX administration, whereas rostral brain areas had delayed increase in rCBV (confirmed by laser Doppler measurements of cortical cerebral blood flow). Moreover, metabolic activity by 14C-2-deoxyglucose autoradiography showed the highest relative increase at the brainstem. To test whether TsTX has high affinity to brainstem neurons, the lateral ventricle was injected with Alexa Fluor 568 TsTX. Although some neurons showed intense fluorescence, the labeling pattern suggests that specific neurons were targeted. Altogether, these results suggest that brainstem areas involved in neurovegetative control are most likely within the primary structures triggering the cascade of symptoms present in SSE.

Effectiveness of Centruroides scorpion antivenom compared to historical controls

BackgroundEnvenomation by North American scorpions of genus Centruroides is associated with a syndrome of neurotoxicity and respiratory compromise that disproportionately affects rural children. Severe scorpion envenomation is rare, which makes treatment difficult to study using conventional controlled clinical trials; and small-scale placebo-controlled trials conducted in tertiary centers are of limited generalizability to the community setting. Open label studies, although safer and easier to conduct, are of limited value unless a suitable comparator group is used. Historical controls may be appropriate when concurrent controls are not feasible or ethical. MethodsA successful placebo-controlled, double-blind clinical trial design was adapted for community use in Arizona and Mexico. A comparator population was established by replacement of the placebo group with a retrospective cohort and preservation of criteria for inclusion, exclusion, dosing and endpoint assessment. Study endpoints were selected to demonstrate the clearest possible difference between treatment groups, while minimizing confounders. Results were summarized and endpoints were directly compared between groups and with the prior double-blind study. ResultsThe clinical syndrome remained evident in 95.9% of the historical cohort (93/97) 4 h after admission, and their cumulative dose of midazolam given between baseline and discharge was 5.29 ± 8.68 mg/kg (range 0–62.8). Among 78 prospectively treated cases, none received midazolam and only 2 (2.8%) remained symptomatic at 4 h. Venom was detectable in the plasma of all antivenom recipients tested, and it dropped by 90% of baseline in 95% of cases studied. ConclusionsThe results of this pragmatic study strongly support the findings of the double-blind, placebo controlled clinical trial of the same antivenom. Recipients of antivenom at rural sites improved at a rate similar to that in the intensive care (ICU) setting, and historical cases resolved at a rate similar to that for untreated ICU controls. Use of antivenom in the primary care setting appeared to be safe and effective and to eliminate the need for intensive care or for transport to a tertiary care center, in all subjects prospectively studied.

Severe scorpion envenomation among children: does hydrocortisone improve outcome? A case-control study

To analyse the efficacy and safety of systemic infusion of hydrocortisone hemisuccinate in children admitted to the intensive care unit with severe scorpion envenomation, we assessed the impact on mortality and length of hospital stay. We conducted a pair-wise, case-control study with 1:1 matching, reviewing records over a 13-year period (1990-2002) for the intensive care unit (ICU) of the Habib Bourguiba University Hospital, Sfax, Tunisia. A total of 184 children were included in the study (92 cases and 92 controls); cases received hydrocortisone hemisuccinate during hospitalization and controls received no steroids. Patients were matched according to age (±2 years), severity factors at admission (pulmonary edema and grades of severity of scorpion envenomation) and scorpion antivenom administration. Cases and controls did not differ significantly in age (4.9 ± 5.5 years vs 6.2 ± 3.8 years; p > 0.05), mean temperature on admission (37.2 ± 1.2 vs 37.2 ± 1.06; p = 0.99) or presence of systemic inflammatory response syndrome (SIRS) (77 vs 70; p = 0.198). The proportion of patients with pulmonary edema was similar in the two groups (77 vs 71; p > 0.05), and in each group 46 patients (50%) received scorpion antivenom (p > 0.05). The use of mechanical ventilation, ICU length of stay and ICU mortality was not significantly different between the studied groups. We detected no significant difference between patients receiving steroids and steroid-free patients in terms of mortality and ICU length of stay. The hydrocortisone hemisuccinate regimen described here had a limited effect in critically ill envenomated children and, therefore, we suggest that it should not be recommended.

Clinical Course of Bark Scorpion Envenomation Managed Without Antivenom

Bark scorpion envenomation is potentially life threatening in children and traditionally treated with antivenom (AV). We sought to describe the clinical course, management, complications and outcome of children with severe scorpion envenomation treated with supportive care during a period when AV was unavailable. A retrospective chart review was performed, all children presenting to a referral hospital between September 1, 2004 and July 31, 2006 with severe scorpion envenomation not receiving AV, were included. A standardized data abstraction form was used to record time of symptom onset, time to healthcare facility (HCF), clinical findings, treatment, complications, and length of stay. Eighty-eight patients were included with mean age of 3.7 years (0.33-12). Mean time to symptom onset was 20 min (0-130) and mean time to HCF was 79 min (10-240). Incidence of clinical manifestations include: neuromuscular agitation, 100 %; opsoclonus, 97 %; hypersalivation, 81 %; tachycardia, 82 %; hypertension, 49 %; vomiting, 38 %; fever, 28 %; respiratory distress, 33 %; and hypoxia, 18 %. Complications included rhabdomyolysis in 18 (20 %) and aspiration in 12 (13 %) patients. Intubation was required in 24 % of patients. The most frequently used agents to control symptoms were benzodiazepines (98 %) followed by opioids (69 %). Intravenous fluids were given to 84 %. Mean length of stay was 29 h (range, 6-73 h). There were no deaths. In addition to the classic findings of neuromuscular hyperactivity, opsoclonus, and hypersalivation, a high incidence of hyperadrenergic findings and respiratory compromise are noted in this series. A significant number of patients required mechanical ventilation. Benzodiazpines and opioids were the most common medications used to control symptoms.

Diabody Mixture Providing Full Protection against Experimental Scorpion Envenoming with Crude Androctonus australis Venom

Androctonus australis is primarily involved in envenomations in North Africa, notably in Tunisia and Algeria, and constitutes a significant public health problem in this region. The toxicity of the venom is mainly due to various neurotoxins that belong to two distinct structural and immunological groups, group I (the AahI and AahIII toxins) and group II (AahII). Here, we report the use of a diabody mixture in which the molar ratio matches the characteristics of toxins and polymorphism of the venom. The mixture consists of the Db9C2 diabody (anti-group I) and the Db4C1op diabody (anti-AahII), the latter being modified to facilitate in vitro production and purification. The effectiveness of the antivenom was tested in vivo under conditions simulating scorpion envenomation. The intraperitoneal injection of 30 μg of the diabody mixture protected almost all the mice exposed to 3 LD(50) s.c. of venom. We also show that the presence of both diabodies is necessary for the animals to survive. Our results are the first demonstration of the strong protective power of small quantities of antivenom used in the context of severe envenomation with crude venom.

Response Letter to the Article: “Scorpion Sting Envenomation in Children: Factors Affecting the Outcome”

Sir, We read the article “Scorpion sting envenomation in children: Factors affecting the outcome.”ByRajniti Prasad, Omprakash Mishra, Nisha Pandey and Tej Bali Singh [1] with interest. Authors mention that “although species specific antivenom is the treatment of choice in scorpion sting envenomation, but it is not available in our part and is very costly.” Haffkine biopharma, Mumbai has developed scorpion antivenom against mesobuthus tamulus and is being marketed since 1997. The cost of one vial is Rs. 350/and maximum dose for pediatric patient is 5 vials which would come to around Rs. 1750/. The cost of monitoring the patient in ICU for 24 h is much higher. The recovery time with anti-venom is just 4 h. We would like to share with the readers that we have done a pioneering work in scorpion antivenom. The RCT done in 2006–2007 comparing the usefulness of Scorpion antivenom, Scorpion antivenom + prazosin as against prazosin alone in severe scorpion sting is published in JPGM Oct 2010 [2]. Dr. Bawaskar who earlier had observed ineffectiveness of antivenom, [3] now after our research admits in BMJ [4] that anti-venom + prazosin is superior to prazosin alone. It is mentioned in the BMJ citing our study that in severe scorpion envenomation the dose of antivenom required is much higher. In fact the dose of scorpion antivenom is the only changed component in his study which has hastened the recovery. The adequate additional doses as suggested by Ismail M [5] would have shortened the recovery time as seen in our study [2]. Depending upon the severity of scorpion envenomation the dose of antivenom will vary and increase. This was not adequately studied in prior studies which were inconclusive for the efficacy of scorpion antivenom. Principle findings of our study [2] were as follows:

Meta-analysis of controlled studies on immunotherapy in severe scorpion envenomation

BackgroundDespite conflicting evidence, specific serotherapy is recommended for scorpion envenomation.MethodsA meta-analysis of prospective or observational controlled studies, comparing intravenous scorpion antivenin (SAV) with control, was performed. Binary outcomes are reported...

Efficacy of anti-scorpion venom serum over prazosin in severe scorpion envenomation

Efficacy of anti-scorpion venom serum over prazosin in severe scorpion envenomation

Scorpion envenomation among children: clinical manifestations and outcome (analysis of 685 cases).

Our objective was to characterize both epidemiologically and clinically manifestations after severe scorpion envenomation and to define simple factors indicative of poor prognosis in children. We performed a retrospective study over 13 years (1990-2002) in the medical intensive care unit (ICU) of a university hospital (Sfax-Tunisia). The diagnosis of scorpion envenomation was based on a history of scorpion sting. The medical records of 685 children aged less than 16 years who were admitted for a scorpion sting were analyzed. There were 558 patients (81.5%) in the grade III group (with cardiogenic shock and/or pulmonary edema or severe neurological manifestation [coma and/or convulsion]) and 127 patients (18.5%) in the grade II group (with systemic manifestations). In this study, 434 patients (63.4%) had a pulmonary edema, and 80 patients had a cardiogenic shock; neurological manifestations were observed in 580 patients (84.7%), 555 patients (81%) developed systemic inflammatory response syndrome (SIRS), and 552 patients (80.6%) developed multi-organ failure. By the end of the stay in the ICU, evolution was marked by the death in 61 patients (8.9%). A multivariate analysis found the following factors to be correlated with a poor outcome: coma with Glasgow coma score ≤ 8/15 (odds ratio [OR] = 1.3), pulmonary edema (OR = 2.3), and cardiogenic shock (OR = 1.7). In addition, a significant association was found between the development of SIRS and heart failure. Moreover, a temperature > 39°C was associated with the presence of pulmonary edema, with a sensitivity at 20.6%, a specificity at 94.4%, and a positive predictive value at 91.7%. Finally, blood sugar levels above 15 mmol/L were significantly associated with a heart failure. In children admitted for severe scorpion envenomation, coma with Glasgow coma score ≤ 8/15, pulmonary edema, and cardiogenic shock were associated with a poor outcome. The presence of SIRS, a temperature > 39°C, and blood sugar levels above 15 mmol/L were associated with heart failure.

Efficacy of anti-scorpion venom serum over prazosin in the management of severe scorpion envenomation

Scorpion venoms cause a massive release of neurotransmitters. Either anti-scorpion venom serum (AScVS) or prazosin has been used in the management of severe scorpion envenomation. To compare the time taken for clinical recovery by patients with severe scorpion envenomation after AScVS therapy with that following prazosin therapy. A prospective, open-labeled clinical trial was undertaken to compare the effects of the AScVS and/or prazosin on clinical recovery in scorpion-stung patients. Eighty-one patients from rural districts of Maharashtra presenting with severe scorpion envenomation were assigned to three treatment groups (AScVS: n = 28; prazosin: n = 25; AScVS + prazosin: n = 28). Severity of scorpion envenomation was graded using a proposed composite clinical scoring system to assess the therapeutic efficacy. AScVS was administered as an intravenous slow bolus, ranging from 40 to 100 ml, depending on the severity of envenomation. Prazosin was given as 1 mg every 3 h. The non-parametric "Kruskal-Wallis" test was used in the statistical analysis and a P-value of 0.05 was considered significant. Mean composite scores of patients from the three groups at the time of admission were comparable. Complete clinical recovery was noted in 4.14 ± 1.6 h and 19.28 ± 5.03 h in the subjects who were administered AScVS and prazosin, respectively (P < 0.001). There was no incidence of anaphylactic reaction to AScVS. Intravenous slow bolus of AScVS given based on the clinical severity of envenomation leads to early recovery than prazosin alone and is well tolerated.

Severe scorpion envenomation in children: Management in pediatric intensive care unit

Scorpion envenomation is a common public health problem worldwide and children are at greater risk of developing severe cardiac, respiratory and neurological complications. The aim of this study was to evaluate the effects of antivenin and/or prazosin use on prognosis of scorpion-envenomed children admitted to pediatric intensive care unit (PICU). The standardized medical records of 45 children hospitalized with severe scorpion sting in PICU were retrospectively evaluated. General characteristics of the children, clinical and laboratory findings, treatment approaches and prognosis were evaluated. The mean age of the patients were 6.1 +/- 4.1 years ranging between 4 month and 15 years. Male to female ratio was 1.8. Thirty-three (71.1%) cases of scorpion stings came from rural areas. Twenty-six (57.8%) of the patients were stung by Androctonus crassicauda. The most common sting localization was the foot-leg (55.6%). The mean duration from the scorpion sting to hospital admission was 4.5 +/- 2.6 hours. The most common findings at presentation were cold extremities (95.5%), excessive sweating (91.1%) and tachycardia (77.7%). The mean leukocyte count, and serum levels of glucose, lactate dehydrogenase, creatine phosphokinase and international normalized ratio were found above the normal ranges. Prazosin was used in all patients, dopamine in 11 (24.4%) and Na-nitroprusside in 4 (8.8%) patients. Two children died (4.4%) due to pulmonary oedema. These children, in poor clinical status at hospital admission, needed mechanical ventilation, and death occurred despite use of antivenin and prazosin in both of them. The current management of children with severe scorpion envenomation consists of administration of specific antivenom and close surveillance in a PICU, where vital signs and continuous monitoring enable early initiation of therapy for life-threatening complications. The aggressive medical management directed at the organ system specifically can be effective. Our data indicated that when admission to hospital is late, the beneficial effect of antivenom and/or prazosin is questionable in severe scorpion stings.

Asymmetric pulmonary edema after scorpion sting: a case report

A 12-year-old boy was referred with acute asymmetric pulmonary edema (APE) four-hour after scorpion sting to Emergency department. On admission, the main clinical manifestations were: dyspnea, tachypnea, and tachycardia. Chest x-ray revealed APE predominantly on the right hemithorax. The patient was treated with oxygen, intravenous frusemide and digoxin and discharged on the sixth hospital day in a good condition. This case report emphasizes the occurrence of asymmetric pulmonary edema after severe scorpion envenomation within few hours immediately after the sting.

Epidemiological, clinical characteristics and outcome of severe scorpion envenomation in South Tunisia: Multivariate analysis of 951 cases

The aim of this retrospective descriptive study was to describe both epidemiologically and clinically manifestations following severe scorpion envenomation and to define simple predictive factors which can be used in routine practice in general Intensive Care Units (ICU) as an indicator of poor prognosis. Cases were collected from hospital patients' files during 13-year (1990–2002) period in the medical Intensive Care Unit of a university hospital (Sfax – Tunisia). The diagnosis of scorpion envenomation was based on a history of scorpion sting. Nine hundred fifty-one patients, who were admitted for a scorpion sting, were analyzed. There were 769 patients (80.8%) in the grade III group (with cardiogenic shock and/or pulmonary edema or severe neurological manifestation (coma and/or convulsion)) and 182 patients (19.2%) in the grade II group (with systemic manifestations). Scorpion envenomation is more frequent in summer; indeed 82.3% of our patients were admitted between June and September. The mean age (±SD) was 14.7 ± 17.4 years, ranging from 0.5 to 90 years. In this study 739 patients (77.8%) had neuromuscular signs, 700 patients (73.6%) had gastrointestinal signs and 585 patients (61.5%) had a pulmonary edema, while 195 patients (20.5%) had a cardiogenic shock. The mean blood sugar on admission was at 11.32 ± 5.66 mmol/l, a high blood sugar level (>11 mmol/l) was observed in 39% of cases. The mean blood urea was at 7.1 ± 3.2 mmol/l, it was above 10 mmol/l in 10.7% of cases. The mean of leucocytes was at 17 418 ± 7833 cells/mm 3, it was above 11 000/mm 3 in 80% of cases. In the end of the stay in ICU, evolution was marked by the improvement of 879 patients (92.5%) while 72 patients (7.5%) died. A multivariate analysis found the following factors to be correlated with a poor outcome: age less than 5 years (OR = 2.27), fever >38.5 °C (OR = 2.79), coma with Glasgow coma score ≤8/15 (OR = 9.87), pulmonary edema (OR = 8.46), leucocytes >25 000 cells/mm 3 (OR = 2.35) and blood urea >8 mmol/l (OR = 4.02). Moreover, in children group, a significant association was found between PRISM score and mortality rate, this model had a high discriminative power with an area under the ROC curve at 0.93. In the adult patients a significant association was found between SAPS II score and mortality rate, this model had a high discriminative power with an area under the ROC curve at 0.82. In summary, in severe scorpion envenomation, age less than 5 years, fever >38.5 °C, coma with Glasgow coma score ≤8/15, pulmonary edema, leucocytes >25 000 cells/mm 3 and blood urea >8 mmol/l were associated with a poor outcome.