Renal function and histology after acute hemorrhage in rats under dexmedetomidine action

PURPOSE: About 50 percent of indications for dialysis in acute renal failure are related to problems originated during the perioperative period. Intraoperative hemodynamic changes lead to renal vasoconstriction and hypoperfusion. Previous studies have not defined the dexmedetomidine renal role in hemorrhage situations. This study evaluated the effect of dexmedetomidine on renal function and histology after acute hemorrhage in rats. METHODS: Covered study with 20 Wistars rats, anesthetized with sodium pentobarbital, 50 mg. kg-1, intraperitoneal, randomized into 2 groups submitted to 30 percent volemia bleeding: DG - iv dexmedetomidine, 3 æg. kg-1 (10 min) and continuous infusion - 3 æg. kg-1. h-1; CG - pentobarbital. For renal clearance estimative, sodium p-aminohippurate and iothalamate were administered. Studied attributes: heart rate, mean arterial pressure, rectal temperature, hematocrit, iothalamate and p-aminohippurate clearance, filtration fraction, renal blood flow, renal vascular resistance, and histological evaluations of the kidneys. RESULTS: DG showed smaller values of heart rate, mean arterial pressure, and renal vascular resistance, but iothalamate clearance and filtration fraction values were higher. There was similarity in p-aminohippurate clearance and renal blood flow. Both groups had histological changes ischemia-like, but dexmedetomidine determined higher tubular dilatation scores. CONCLUSION: In rats, after acute hemorrhage, dexmedetomidine determined better renal function, but higher tubular dilation scores.

OBJETIVO: Cerca de 50 por cento de indicações de diálise em insuficiência renal aguda vêm de problemas do perioperatório. Alterações na hemodinâmica intra-operatória levam a vasoconstrição renal e hipoperfusão. Estudos prévios não definiram o papel renal da dexmedetomidina em hemorragia. Foram estudados os efeitos da dexmedetomidina na função e histologia renais, em ratos, após hemorragia aguda. MÉTODOS: Estudo encoberto com 20 ratos Wistar, anestesiados com pentobarbital sódico intraperitoneal, 50 mg. kg-1, divididos aleatoriamente em 2 grupos sob sangramento de 30 por cento da volemia: GD - dexmedetomidina iv, 3 æg. kg-1 (10 min), e infusão contínua, 3 æg. kg-1. h-1; GC - pentobarbital. Para estimar depuração renal, administraram-se para-aminohipurato e iotalamato de sódio. Atributos estudados: freqüência cardíaca, pressão arterial média, temperatura retal, hematócrito, depuração de para-aminohipurato e iotalamato, fração de filtração, fluxo sangüíneo renal, resistência vascular renal, análise histológica dos rins. RESULTADOS: Em GD, houve valores menores de freqüência cardíaca, pressão arterial média e resistência vascular, mas valores maiores de depuração de iotalamato e fração de filtração. A depuração de para-aminohipurato e o fluxo sangüíneo foram similares nos grupos. As alterações histológicas foram compatíveis com isquemia e houve maior dilatação tubular em GD. CONCLUSÃO: Em ratos, após hemorragia aguda, a dexmedetomidina determinou melhor função renal, porém maior dilatação tubular.

Renal function and histology after acute hemorrhage in rats under dexmedetomidine action.

PURPOSE: About 50 % of indications for dialysis in acute renal failure are related to problems originated during the perioperative period. Intraoperative hemodynamic changes lead to renal vasoconstriction and hypoperfusion. Previous studies have not defined the dexmedetomidine renal role in hemorrhage situations. This study evaluated the effect of dexmedetomidine on renal function and histology after acute hemorrhage in rats. METHODS: Covered study with 20 Wistars rats, anesthetized with sodium pentobarbital, 50 mg.kg(-1), intraperitoneal, randomized into 2 groups submitted to 30% volemia bleeding: DG - iv dexmedetomidine, 3 microg.kg(-1) (10 min) and continuous infusion - 3 microg.kg(-1).h(-1); CG - pentobarbital. For renal clearance estimative, sodium p-aminohippurate and iothalamate were administered. Studied attributes: heart rate, mean arterial pressure, rectal temperature, hematocrit, iothalamate and p-aminohippurate clearance, filtration fraction, renal blood flow, renal vascular resistance, and histological evaluations of the kidneys. RESULTS: DG showed smaller values of heart rate, mean arterial pressure, and renal vascular resistance, but iothalamate clearance and filtration fraction values were higher. There was similarity in p-aminohippurate clearance and renal blood flow. Both groups had histological changes ischemia-like, but dexmedetomidine determined higher tubular dilatation scores. CONCLUSION: In rats, after acute hemorrhage, dexmedetomidine determined better renal function, but higher tubular dilation scores.

Clonidina como droga adjuvante no tratamento da síndrome de abstinência alcoólica em unidade de terapia intensiva: relato de caso / Clonidine as adjuvant therapy for alcohol withdrawal syndrome in intensive care unit: case report

JUSTIFICATIVA E OBJETIVOS: A sedação de dependentes de álcool e drogas em Unidades de Terapia Intensiva (UTI) é um desafio pela elevada incidência de tolerância às drogas sedativas e da elevada freqüência de síndromes de abstinência. O objetivo deste relato é mostrar um caso de paciente jovem admitido na UTI que desenvolveu síndrome de abstinência alcoólica e tolerância às drogas sedativas, solucionadas somente após o uso de clonidina. RELATO DO CASO: Paciente do sexo masculino, 18 anos, dependente de álcool, tabaco, cocaína e maconha, vítima de acidente por arma de fogo, foi admitido na UTI no 1º dia de pós-operatório de enterectomia, após aspiração de conteúdo gástrico durante reintubação traqueal. Evolução clínica: drogas vasoativas até o 4º dia de internação e broncopneumonia bilateral com derrame pleural e necessidade de ventilação artificial até o 15º dia. O esquema de sedação inicial utilizado foi a associação de midazolam e fentanil. A partir do 4º dia, o paciente apresentou vários episódios de agitação psicomotora, mesmo com a associação de lorazepam no 6º dia. No 9º dia, o paciente recebeu as maiores doses dos fármacos, mas permanecia agitado. Optou-se pela associação de dexmedetomidina, que reduziu as doses das outras drogas em 35 por cento e diminuiu a agitação. No 12º dia, o midazolam e a dexmedetomidina foram substituídos pela infusão de propofol, com piora do quadro. No 13º dia, foi associada clonidina ao esquema de sedação, com resolução do quadro de agitação. No 14º dia, o propofol foi suspenso, sendo mantida a infusão de fentanil e reintroduzida a infusão de midazolam, com doses respectivamente 75 por cento e 65 por cento menores em relação ao pico de uso destas drogas. No 15º dia, o paciente foi extubado e teve alta da UTI. CONCLUSÕES: A droga de escolha para o tratamento da síndrome de abstinência alcoólica é o benzodiazepínico...

BACKGROUND AND OBJECTIVES: Sedation of patients with past history of alcohol and drug abuse in Intensive Care Units (ICU) is a challenge due to the high incidence of sedative drugs tolerance and withdrawal syndromes. This report aimed at describing a case of a young patient admitted to the ICU who developed alcohol withdrawal syndrome and tolerance to sedatives, resolved only after clonidine administration. CASE REPORT: Male patient, 18 years old, alcohol, tobacco, cocaine and marijuana abuser, victim of firearm accident, who was admitted to the ICU in the first post-enterectomy day, after gastric content aspiration during tracheal re-intubation. Clinical evolution was: vasoactive drugs up to the 4th day; bilateral bronchopneumonia with pleural effusion and need for artificial ventilation up to the 15th day. Initial sedation scheme was the association of midazolam and fentanyl. As from the 4th day, patient presented with several psychomotor agitation episodes, even after the association of lorazepam in the 6th day. In the 9th day, patient received the largest doses but remained agitated. Dexmedetomidine was associated, which has decreased other drug doses in 35% and has improved agitation. In the 12th day, midazolam and dexmedetomidine were replaced by propofol infusion with worsening of agitation. In the 13th day, clonidine was associated to the sedation scheme with total resolution of agitation. Propofol was withdrawn in the 14th day, fentanyl was maintained and midazolam infusion was restarted, with doses 75% and 65% lower as compared to peak doses of such drugs. Patient was extubated in the 15th day and was discharged from ICU. CONCLUSIONS: Benzodiazepines should remain the drugs of choice for the treatment of acute alcohol withdrawal syndrome...

JUSTIFICATIVA Y OBJETIVOS: La sedación de dependientes de alcohol y drogas en Unidades de Terapia Intensiva (UTI) es un desafío por la elevada incidencia de tolerancia a las drogas sedativas y de la elevada frecuencia de síndromes de abstinencia. El objetivo de este relato es mostrar un caso de un paciente joven admitido en la UTI que desarrolló síndrome de abstinencia alcohólica y tolerancia a las drogas sedativas, solucionadas solamente después del uso de clonidina. RELATO DEL CASO: Paciente del sexo masculino, 18 años, dependiente de alcohol, tabaco, cocaína y mariguana, víctima de accidente por arma de fuego, fue admitido en la UTI en el 1º día de post-operatorio de enterectomía, después de aspiración de contenido gástrico durante reintubación traqueal. Evolución clínica: drogas vasoactivas hasta el 4º día de internación y broncopneumonia bilateral con derrame pleural y necesidad de ventilación artificial hasta el 15º día. El esquema de sedación inicial utilizado fue la asociación de midazolan y fentanil. A partir del 4º día, el paciente presentó varios episodios de agitación psicomotora, mismo con la asociación de loracepam en el 6° día. En el 9° día, el paciente recibió las mayores dosis de los fármacos, más permanecía agitado. Se optó por la asociación de dexmedetomidina, que redujo las dosis de las otras drogas en 35% y diminuyó la agitación. En el 12° día, el midazolan y la dexmedetomidina fueron substituidos por la infusión de propofol, con empeoramiento del cuadro. En el 13° día, fue asociada clonidina al esquema de sedación, con resolución del cuadro de agitación. En el 14° día, el propofol fue suspenso, siendo mantenida la infusión de fentanil y reintroducida la infusión de midazolan, con dosis respectivamente 75% y 65% menores en relación al pico de uso de estas drogas. En el 15° día, el paciente fue extubado y tuvo alta de la UTI. CONCLUSIONES: La droga escogida para el tratamiento del síndrome de abstinencia alcohólico es el benzodiazepínico...

[Clonidine as adjuvant therapy for alcohol withdrawal syndrome in intensive care unit: case report.]. / Clonidina como droga adjuvante no tratamento da síndrome de abstinência alcoólica em unidade de terapia intensiva: relato de caso.

BACKGROUND AND OBJECTIVES: Sedation of patients with past history of alcohol and drug abuse in Intensive Care Units (ICU) is a challenge due to the high incidence of sedative drugs tolerance and withdrawal syndromes. This report aimed at describing a case of a young patient admitted to the ICU who developed alcohol withdrawal syndrome and tolerance to sedatives, resolved only after clonidine administration. CASE REPORT: Male patient, 18 years old, alcohol, tobacco, cocaine and marijuana abuser, victim of firearm accident, who was admitted to the ICU in the first post-enterectomy day, after gastric content aspiration during tracheal re-intubation. Clinical evolution was: vasoactive drugs up to the 4th day; bilateral bronchopneumonia with pleural effusion and need for artificial ventilation up to the 15th day. Initial sedation scheme was the association of midazolam and fentanyl. As from the 4th day, patient presented with several psychomotor agitation episodes, even after the association of lorazepam in the 6th day. In the 9th day, patient received the largest doses but remained agitated. Dexmedetomidine was associated, which has decreased other drug doses in 35% and has improved agitation. In the 12th day, midazolam and dexmedetomidine were replaced by propofol infusion with worsening of agitation. In the 13th day, clonidine was associated to the sedation scheme with total resolution of agitation. Propofol was withdrawn in the 14th day, fentanyl was maintained and midazolam infusion was restarted, with doses 75% and 65% lower as compared to peak doses of such drugs. Patient was extubated in the 15th day and was discharged from ICU. CONCLUSIONS: Benzodiazepines should remain the drugs of choice for the treatment of acute alcohol withdrawal syndrome. However in this report, only adjuvant clonidine was able to adequately treat the patient.

Effect of high-dose fentanyl on renal function in dogs

Our objective was to determine the effects of high-dose fentanyl on canine renal function (RF). We anesthetized with sodium pentobarbital (SP) 16 dogs, randomly divided into 2 groups:in G1, SP was given alone, and in G2, combined with 0.05 mg.kg(-1) fentanyl. All animals were ventilated artificially and had catheterized left and righ femoral veins and left femoral artery for fluid infusion, drug administration, blood collection, and hemodynamic measurement. Urine was collected throughout the experiment. Attributes of RF were studied. SP did not alter RF, which was significantly altered by fentanyl. In G2, slower heart rates, mean arterial pressure, creatinine clearance, urinary output, osmolar clearance and fractional excretion of sodium and potassium were observed. G1 had a behavior attributed to extracellular volume expansion and no RF alterations. In G2, we observed significant decreases in RF due to opioid-induced hemodynamic changes, not discarding the possible action of aldosterone.