The effect of dexamethasone on post-tonsillectomy nausea, vomiting and bleeding / Efeito da dexametasona sobre sangramento, vômito e náusea pós-amigdalectomia

It has been stated, that the administration of Dexamethasone has an impact on the morbidity following tonsillectomy. OBJECTIVE: To re-calculate the blood values for Dexamethasone when given as fixed doses and to evaluate the effect of Dexamethasone on post-operative nausea, vomiting and bleeding rates following tonsillectomy. MATERIALS AND METHODS: The charts of 272 children (2-15 years) who had undergone tonsillectomy were analyzed. The rates of post-operative nausea, vomiting and bleeding in relation to Dexamethasone were calculated-in general and different doses (0 mg/kg, <0.15 mg/kg, >0.15 mg/kg). STUDY DESIGN: Retrospective cohort study. RESULTS: Dexamethasone was administered in 121 children (43.7 percent) according to the preference of the anesthesist (mean dose: 0.2 +/- 0.12 mg/kg; range: 0.04 - 0.62 mg/kg). There was no significant difference in nausea and vomiting (p=0.953) or bleeding (p=0.827) across groups receiving or not receiving Dexamethasone. Stratification into three different groups of Dexamethasone concentration also did not identify a dose-related risk of postoperative nausea or vomiting (p=0.98) or bleeding (p=0.71). CONCLUSION: At least under common non-controlled conditions in the clinic, Dexamethasone does not appear to have an effect on nausea or vomiting or bleeding following tonsillectomy.

É conhecido o impacto da administração de dexametasona sobre a morbidade no pós-operatório de amigdalectomia. OBJETIVO: Recalcular os valores séricos para dexametasona quando administrada em doses fixas e avaliar seus efeitos sobre as taxas de náusea, vômito e sangramento no pós-operatório de amigdalectomia. MATERIAIS E MÉTODOS: Analisamos os prontuários de 272 crianças (idades entre 2-15 anos) submetidas a amigdalectomias. As taxas de náusea, vômitos e sangramentos foram calculadas para a dexametasona em geral e em diferentes doses (0 mg/kg; <0,15 mg/kg; >0,15 mg/ kg). TIPO DE ESTUDO: Coorte retrospectivo. RESULTADOS: A dexametasona foi administrada em 121 crianças (43,7 por cento), baseado na preferência do anestesista (dose média: 0,2 +/- 0,12 mg/kg; variação: 0,04 - 0,62 mg/kg). Não houve diferença significativa em termos de náuseas e vômitos (p=0,953) ou sangramento (p=0,827) entre os grupos de pacientes que receberam e não receberam dexametasona. Mesmo a estratificação em três grupos de diferentes concentrações de dexametasona não identificou risco dose-dependente de náusea ou vômito pós-operatório (p=0,98) ou sangramento (p=0,71). CONCLUSÃO: Pelo menos sob condições não-controladas normais da clínica, a dexametasona parece não ter efeito sobre a incidência de náuseas, vômito ou sangramento após amigdalectomia.

Adrenalectomy Abolishes Fasting-induced Down-regulation of NADPH-diaphorase in the Rat Paraventricular Nucleus

This study was conducted to define the molecular mechanism of fasting-induced down-regulation of neuronal nitric oxide synthase (nNOS) expression in the hypothalamic paraventricular nucleus (PVN). Rats were adrenalectomized (ADX), and then either underwent food deprivation or received varying doses of dexamethasone for 48 h. The brain tissues were processed for NADPH-diaphorase (NADPH-d) staining, a histochemical marker of nNOS enzyme activity. Both the ADX and the sham operated rats showed a significant weight loss after 48 h of food deprivation. Food deprivation decreased the number of NADPH-d containing cells in the PVN of sham rats, however, not in the ADX rats. Dexamethasone dose- dependently decreased NADPH-d cells in the PVN of ADX rats. The effect of ADX or dexamethasone was limited to the parvocellular subdivision of PVN. These results suggest that the adrenal glucocorticoids may down-regulate nNOS expression in the PVN during food deprivation.