Carlos Faria Santos Amaral

Approaches to the treatment of scorpion envenoming

A total of 3866 patients stung by Tityus serrulatus scorpion was admitted to Hospital João XXIII, in Belo Horizonte, Brazil, over a 16-year period (an average of 241 cases per year). Of these, 73% were adults and 27% were children aged less than 14 years. The moderate or benign cases were treated with symptomatic measures and/or i.v. antivenom, whereas 168 severely envenomed children were treated in the Intensive Care Unit. Lung oedema was unilateral in several cases, with the presence of air bronchograms and a peripheral distribution, suggesting that a noncardiogenic factor is also involved in the genesis of lung oedema. The treatment consisted of symptomatic measures, support of vital functions and i.v. antivenom. The mortality was 1% among children and 0.28% for the total number of patients.

Serum levels of cytokines in patients envenomed by Tityus serrulatus scorpion sting.

Seventeen patients stung by Tityus serrulatus scorpion were classified as mild (pain at the site of the sting, n = 6), moderate (local pain and one of the following manifestations: vomiting, psychomotor agitation, prostration, sweating, tachypnea, tachycardia and mild arterial hypertension, n = 10) and severe cases (equal moderate cases plus cardiac failure, pulmonary edema and shock, n = 1). Venous blood was sampled for biochemical and hematological analysis and for IL-1alpha, IL-6, IL-10, TNF-alpha, IFN-gamma and GM-CSF ELISAs at the time of hospital admission, 6 h (moderate and severe cases), and 12, 18, 36 and 72 h (severe case) later. Ten age-matched healthy volunteers were used as control. Increased serum levels of IL-1alpha was noticed in all patients, high levels of IL-6, IFN-gamma and GM-CSF were observed only in a patient with severe envenomation. Our data suggest that a systemic inflammatory response-like syndrome is triggered during severe envenomation caused by T. serrulatus sting and that release of cytokines may be involved in this response.

Acute pulmonary edema after Tityus serrulatus scorpion sting in children

Acute pulmonary edema due to scorpion toxins has been attributed to acute left ventricular failure resulting from massive catecholamine release or myocardial damage induced by the venom.1–3 It has been proposed that pulmonary edema could also result from increased pulmonary vascular permeability produced by vasoactive substances that may be released by the venom.4 This report presents radiologic, electrocardiographic, enzymatic, echocardiographic and histopathologic evidence that support both cardiogenic and noncardiogenic factors in the pathogenesis of acute pulmonary edema after Tityus serrulatus scorpion sting in children.

Renal cortical necrosis following Bothrops jararaca and B. jararacussu snake bite

Out of 22 patients admitted to the Intensive Care Unit of the Hospital das Clínicas, Federal University of Minas Gerais, with acute renal failure following Bothrops snake bite, 7 had renal cortical necrosis. This complication was suspected when the oligoanuric phase ranged from 21 to 28 days or when the patient, in spite of having a polyuric phase, maintained elevated blood levels of urea and creatinine after the interruption of the dialysis program, and was confirmed by a kidney biopsy. Three patients died and in two of them renal cortical necrosis was found at necropsy. Four patients were discharged from the hospital and follow-up was possible in two of them who showed recovery of renal function. Vasospasm, direct nephrotoxicity of Bothrops venom and/or disseminated intravascular coagulation leading to vascular occlusion and renal ischemia are the proposed pathogenetic mechanisms to explain renal cortical necrosis following Bothrops snake bite.

Insuficiência renal aguda secundária a acidentes ofídicos botrópico e crotálico. Análise de 63 casos

Sessenta e tres pacientes com insuficiencia renal aguda secundaria a acidente ofidico foram tratados no CTI do Hospital das Clinicas da UFMG. Em 32 pacientes (51%) o acidente foi produzido por serpentes do genero Bothrops (grupo bio-tropico) e em 32 pacientes (49%) pela cascavel sul-americana (grupo crotalico). As principais complicacoes apresentadas pelos pacientes foram a uremia (100% dos casos), hiperpotassemia (89% dos casos), anemia (78% dos casos), infeccao urinaria (37% dos casos), hiper-hidratacao (17% dos casos), parada cardiaca (14% dos casos) e edema agudo dos pulmoes (11% dos casos). Cinco pacientes do grupo crotalico (16%) tiveram insuficiencia respiratoria aguda atribuida a acao neurotoxica do veneno, quatro dos quais se recuperaram completamente. Sete pacientes do grupo botropico (22%) tiveram necrose cortical renal diagnosticada em cinco atraves da biopsia renal e em dois na necropsia. Quarenta e cinco pacientes (71%) foram tratados com dialise peritoneal e a hemodialise foi necessaria em dois pacientes, um dos quais havia sido submetido a dialise peritoneal. Em 17 pacientes (27%) o tratamento foi conservador. Cinquenta e cinco pacientes receberam alta hospitalar, quatro dos quais com insuficiencia renal cronica secundaria a necrose cortical renal e oito (13%) faleceram. Os obitos foram atribuidos a edema pulmonar agudo em quatro pacientes, a estado de choque em dois pacientes e a coma e infeccao respiratoria apos parada cardiaca em dois pacientes.Sessenta e tres pacientes com insuficiencia renal aguda secundaria a acidente ofidico foram tratados no CTI do Hospital das Clinicas da UFMG. Em 32 pacientes (51%) o acidente foi produzido por serpentes do genero Bothrops (grupo bio-tropico) e em 32 pacientes (49%) pela cascavel sul-americana (grupo crotalico). As principais complicacoes apresentadas pelos pacientes foram a uremia (100% dos casos), hiperpotassemia (89% dos casos), anemia (78% dos casos), infeccao urinaria (37% dos casos), hiper-hidratacao (17% dos casos), parada cardiaca (14% dos casos) e edema agudo dos pulmoes (11% dos casos). Cinco pacientes do grupo crotalico (16%) tiveram insuficiencia respiratoria aguda atribuida a acao neurotoxica do veneno, quatro dos quais se recuperaram completamente. Sete pacientes do grupo botropico (22%) tiveram necrose cortical renal diagnosticada em cinco atraves da biopsia renal e em dois na necropsia. Quarenta e cinco pacientes (71%) foram tratados com dialise peritoneal e a hemodialise foi necessaria em dois pacientes, um dos quais havia sido submetido a dialise peritoneal. Em 17 pacientes (27%) o tratamento foi conservador. Cinquenta e cinco pacientes receberam alta hospitalar, quatro dos quais com insuficiencia renal cronica secundaria a necrose cortical renal e oito (13%) faleceram. Os obitos foram atribuidos a edema pulmonar agudo em quatro pacientes, a estado de choque em dois pacientes e a coma e infeccao respiratoria apos parada cardiaca em dois pacientes.

Electrocardiographic, enzymatic and echocardiographic evidence of myocardial damage after tityus serrulatus scorpion poisoning

Abstract The cardiovascular manifestations after a Tityus serrulatus scorpion sting consist of arterial hypertension or hypotension, heart failure, pulmonary edema, shock and electrocardiographic changes. 1 Pulmonary edema evoked by scorpion toxin has been attributed to left ventricular failure induced by the venom or to increased pulmonary vascular permeability produced by vasoactive substances that might be released by the venom. 2 The demonstration of myocardial damage and depressed left ventricular systolic function in patients with pulmonary edema following scorpion sting could support the hypothesis that this severe complication is cardiogenic in origin. This report describes results of electrocardiographic, enzymatic and echocardiographic studies in 5 patients with severe envenomation after a Tityus serrulatus scorpion sting.

Immunotherapy for scorpion envenoming in Brazil

Using the ELISA we have shown that in rats subcutaneously injected with Tityus serrulatus scorpion venom there is a fast absorption rate, a fast and high distribution of venom to tissues, a great affinity of the venom for the tissues and a slow elimination half-life. Because of these experimental data, i.v. immunotherapy should be given to patients stung by scorpions as soon as possible after hospital admission. The severity of scorpion envenoming is related to plasma venom concentration (ELISA). The high levels of plasma scorpion venom antigens (ELISA) were cleared 1 h after the infusion of antivenom (5-30 ml of Fab2 fragment) and high concentrations of circulating antivenom persisted for at least 24 h, confirming the efficacy of immunotherapy to neutralise circulating venom. Some symptoms (e.g. local pain and vomiting) decreased 1 h after the starting of immunotherapy, whereas the other symptoms disappeared from 12-48 h later. Using our tripartite approach of treating scorpion envenoming (symptomatic measures, support of vital functions and serotherapy), the mortality rate was very low (0.28%).

ELISA for the detection of toxic antigens in experimental and clinical envenoming by Tityus serrulatus scorpion venom.

An ELISA was developed for identification of circulating toxic antigens from Tityus serrulatus scorpion venom. The toxic fraction from the scorpion venom was purified by Sephadex G-50 chromatography and immunoaffinity techniques were used for identifying antibodies that reacted with this fraction. These antibodies were used to develop a sandwich-type ELISA. The specificity of the assay was demonstrated by its capacity for identifying mice that were experimentally inoculated with T. serrulatus venom from those inoculated with Phoneutria nigriventer spider venom, Apis mellifera bee venom and Bothrops atrox, Crotalus durissus terrificus, Lachesis muta muta and Micrurus frontalis snake venoms. Measurable absorbance signals were obtained with 0.1 ng of venom per assay. The ELISA also detected antigens in the sera of patients systemically envenomed by T. serrulatus. Therefore, this ELISA could be a valuable tool for clinicians and epidemiologists, owing to its sensitivity and specificity.

Brazilian medical students’ attitudes towards patient-centered care

Background: The doctor-patient relationship is essencial to medical care (Engel 1980; Balint 1984), however, medical schools focus mainly on biomedical subjects and don’t give the necessary attention to communication skills, humanistic attitudes, and professional values (Haidet et al. 2001, 2002). Methods: Attitudes of medical students towards the doctor-patient relationship have been examined and the Patient-Practitioner Orientation Scale (PPOS) has been used to measure students’ and practitioners’ patient-centered beliefs, first in USA (Haidet et al. 2002), and then in several other countries (Choi & Moon 2005; Tsimtsiou et al. 2005; Shankar et al. 2006). This study aimed to examine the attitudes of Brazilian medical students towards the doctor-patient relationship by using the PPOS. The scale was translated into Portuguese and was administered to approximately 800 students in their first, fifth, seventh, ninth, tenth and twelfth semesters of medical school along with a socio-demographic questionnaire. Results: A total of 738 students (>90%) completed data collection. For the entire cohort, female gender (p < 0.000), later semester in medical school (p < 0.000), primary-care specialty choice (p < 0.02) and lower familial income (p < 0.03) were significantly associated with more patient-centered attitudes. Sharing sub-scores, measuring beliefs about power and information between physician and patient, were significantly more patient-centered for twelfth semester male students than for first semester males (p < 0.000), but not for female students. Caring sub-scores, which measure beliefs about attending to patients emotions and lifestyle, did not change with the years of school. In general, Caring scores were considerably higher than Sharing scores. Total PPOS scores in Brazil are comparable to those found among medical students in the United States, however they are considerably higher than PPOS total scores in Nepal, Greece, and Korea. Conclusions: Communication skills and patient care needs to be critically examined by Brazilian teachers and students aiming to change attitudes toward the doctor-patient relationship to be more patient-centered attitudes.

Children with adrenergic manifestations of envenomation after Tityus serrulatus scorpion sting are protected from early anaphylactic antivenom reactions.

The incidence of early anaphylactic reactions to scorpion antivenom given i.v. after Tityus serrulatus scorpion sting was evaluated in 103 children aged up to 15 years in Belo Horizonte, Brazil. Patients without adrenergic manifestations (Group 1, n = 28) were compared with those who presented systemic involvement that included adrenergic manifestations (Group 2, n = 75). Data were recorded on a proforma and the presence or absence of early anaphylactic reaction was cross-tabulated according to clinical features, sex, age and volume of antivenom used in the treatment. Unpaired Students t-test was used to calculate significance of differences in age and volume of antivenom used. Multivariate logistic regression was used to determine the effects of clinical features and volume of antivenom as predictors of early anaphylactic reaction to antivenom treatment. Twelve (42.9%) of 28 children included in Group 1 presented early anaphylactic reactions compared with 6 (8%) of 75 children of Group 2 (OR = 8.63; 95% CI: 2.88, 25.7). The reactions were more severe in Group 1. There were no significant differences with respect to age and sex. After adjusting for clinical form, volume of antivenom was not significantly associated with presence of reactions (OR = 1.11; 95% CI: 0.70, 2.80 for each 5.0 ml of antivenom administered). The results show that children with adrenergic manifestations after T. serrulatus scorpion sting had significantly lower anaphylactic reactions to antivenom than those without these manifestations.