Effect of Repeated Exposure to Sevoflurane on Electroencephalographic Alpha Oscillation in Pediatric Patients Undergoing Radiation Therapy: A Prospective Observational Study.

BACKGROUND: Pharmacological tolerance is defined as a decrease in the effect of a drug over time, or the need to increase the dose to achieve the same effect. It has not been established whether repeated exposure to sevoflurane induces tolerance in children. METHODS: We conducted an observational study in children younger than 6 years of age scheduled for multiple radiotherapy sessions with sevoflurane anesthesia. To evaluate the development of sevoflurane tolerance, we analyzed changes in electroencephalographic spectral power at induction, across sessions. We fitted individual and group-level linear regression models to evaluate the correlation between the outcomes and sessions. In addition, a linear mixed-effect model was used to evaluate the association between radiotherapy sessions and outcomes. RESULTS: Eighteen children were included and the median number of radiotherapy sessions per child was 28 (interquartile range: 10 to 33). There was no correlation between induction time and radiotherapy sessions. At the group level, the linear mixed-effect model showed, in a subgroup of patients, that alpha relative power and spectral edge frequency 95 were inversely correlated with the number of anesthesia sessions. Nonetheless, this subgroup did not differ from the other subjects in terms of age, sex, or the total number of radiotherapy sessions. CONCLUSIONS: Our results suggest that children undergoing repeated anesthesia exposure for radiotherapy do not develop tolerance to sevoflurane. However, we found that a group of patients exhibited a reduction in the alpha relative power as a function of anesthetic exposure. These results may have implications that justify further studies.

Uso de opioides en pacientes paliativos oncológicos al momento de fallecer: “el mito de la morfina” / Use of opioids in palliative cancer patients at the time of his death: the myth of morphine

Objetivos: determinar cuáles fueron los opioides usados al momento de morir, tiempo de uso e incremento de dosis. Materiales y Métodos: Pacientes paliativos ingresados el año 2008 al Instituto Nacional del Cáncer. Los datos fueron obtenidos del libro de ingresos y registro informático de recetas. Resultados: Ingresaron 456 pacientes, de éstos fallecieron 170 (37 por ciento), con mediana de edad de 66 años (16-97) y 53 por ciento mujeres. Al momento del fallecimiento, un 14 por ciento no estaba recibiendo opioides. Los opioides utilizados fueron codeína, 11,7 por ciento; tramadol, 32,4 por ciento; oxicodona, 0,7 por ciento; morfina, 37,2 por ciento; metadona, 4,8 por ciento; buprenorfina TTS, 10,3 por ciento; y fentanilo TTS, 2,8 por ciento. En todos, las dosis promedio fueron bajas (morfina, 26,9 mg/día; metadona, 17,9 mg/ día; tramadol, 142,8 mg/día; buprenorfina, 19 ug/h; y fentanilo, 19,5 ug/h). No se evidenció un incrementosignificativo en las dosis. El tiempo promedio de uso desde el último cambio de opioide fue 41,3 DE+63,5 días con una mediana de 26 días (1 a 366). No se encontró diferencia entre los opioides. Discusión: La mitad de los pacientes fallecidos estaban en OMSIII. De los usuarios de opioides potentes, solo un 37 por ciento estaba con morfina. Las dosis promedio de todosfueron bajas. El tiempo transcurrido entre el inicio del opioide y la muerte no difirió entre opioides. En suma, no todos los pacientes paliativos en nuestra población falleció recibiendo morfina, no se evidenciaron diferencias en el tiempo de uso del opioide ni un aumento de la dosis, lo cual desmitifica dos creencias: “si uso morfina me voy a morir antes” y “si uso morfina deberé aumentar las dosis y me haré dependiente”.

Objectives: to determine which were the opioids used at the time of death, time usage and increasing doses. Materials and Methods: Palliative patients admitted to the National Cancer Institute in 2008. Data were obtained from the book income and prescription computer records. Results: 456 patients were treated, 170 died (37 percent), with median age of 66 (16-97) and 53 percent women. At death time, 14 percent was not receiving opioids. Used opioids were 11.7 percent codeine; 32.4 percent tramadol; 0.7 percent oxycodone; 37.2 percent morphine; 4.8 percent methadone; 10.3 percent TTS buprenorphine and 2.8 percent TTS fentanyl. All average doses were low (morphine 26,9 mg/day, methadone 17,9 mg/ day, tramadol, 142,8 mg/ day, buprenorphina 19 ug/h and fentanyl 19,5 ug/h). A significant increase in dose was not observed. Average time since the last change of opiode was 41.3 DE+63.5 days with a median of 26 days (1-366), no difference was found between different opioids. Discussion: Half of the patients who died were in OMSIII. Only 37 percent of strong opioids users was using morphine. The average doses of all were low. Time between start opioid use and death was no different for different opioids. So not all palliative patients died using morphine, and no differences were observed in opioids time of use, or increasing doses which demystifies two beliefs: “If I use morphine I will die prematurely” and “If I use morphine, I will increase dose and I will be dependent ”.