Luiz Vicente Garcia

Biochemical and genetic analysis of butyrylcholinesterase (BChE) in a family, due to prolonged neuromuscular blockade after the use of succinylcholine

Butyrylcholinesterase (BChE) is a plasma enzyme that catalyzes the hydrolysis of choline esters, including the muscle-relaxant succinylcholine and mivacurium. Patients who present sustained neuromuscular blockade after using succinylcholine usually carry BChE variants with reduced enzyme activity or an acquired BChE deficiency. We report here the molecular basis of the BCHE gene underlying the slow catabolism of succinylcholine in a patient who underwent endoscopic nasal surgery. We measured the enzyme activity of BChE and extracted genomic DNA in order to study the promoter region and all exons of the BCHE gene of the patient, her parents and siblings. PCR products were sequenced and compared with reference sequences from GenBank. We detected that the patient and one of her brothers have two homozygous mutations: nt1615 GCA > ACA (Ala539Thr), responsible for the K variant, and nt209 GAT > GGT (Asp70Gly), which produces the atypical variant A. Her parents and two of her brothers were found to be heterozygous for the AK allele, and another brother is homozygous for the normal allele. Sequence analysis of exon 1 including 5′UTR showed that the proband and her brother are homozygous for –116GG. The AK/AK genotype is considered the most frequent in hereditary hypocholinesterasemia (44%). This work demonstrates the importance of defining the phenotype and genotype of the BCHE gene in patients who are subjected to neuromuscular block by succinylcholine, because of the risk of prolonged neuromuscular paralysis.

Intravenous clonidine in the induced arterial hypotension technique for tympanoplasty

BACKGROUND AND OBJECTIVES Induced arterial hypotension is an effective technique to decrease surgical bleeding. Clonidine is an a2-agonist with central action which was proven to be safe in anesthesia. This study aimed at evaluating the efficacy of intravenous clonidine as the primary drug for induced arterial hypotension. METHODS Participated in this prospective double-blind study 36 patients of both genders, physical status ASA I and II, who were randomly distributed in three groups of 12 patients receiving the following preanesthetic medication 15 minutes before anesthetic induction: 3 microg.kg-1 clonidine (C3), 5 microg.kg-1 clonidine (C5) or 0.9% saline solution (Control). Anesthesia was maintained with isoflurane in a maximum concentration of 2%. BP and HR were recorded before, 1 and 5 minutes after induction and at every 5 minutes of anesthesia. Patients receiving 2% isoflurane for more than 15 minutes and not presenting SBP below 80 mmHg were administered sodium nitroprusside to induce arterial hypotension. RESULTS Sodium nitroprusside was needed in three C3 group patients (25%), one C5 group patient (8%) and eight control group patients (66%). Total nitroprusside dose to induce arterial hypotension in the control group was higher as compared to groups C3 and C5 (p < 0.01). The incidence of complications was similar among groups. CONCLUSIONS Intravenous clonidine may lead to induced hypotension during tympanoplasties under balanced anesthesia with isoflurane concentration limited to 2%. In the conditions of this study, clonidine has not affected anesthetic quality and emergence time.JUSTIFICATIVA Y OBJETIVOS: A hipotension arterial inducida es una tecnica eficaz para diminuir el sangramiento durante actos quirurgicos. La clonidina es un a2-agonista de acion central que ya se mostro segura en anestesia. El objetivo de este estudio fue verificar la eficiencia de la clonidina por via venosa como droga principal en la hipotension arterial controlada. METODO: Participaron del estudio prospectivo y duplamente encubierto, 36 pacientes de ambos sexos, estado fisico ASA I y II, divididos aleatoriamente en tres grupos de 12 pacientes que recibieron medicacion pre-anestesica: clonidina 3 µg.kg-1 (C3), clonidina 5 µg.kg-1 (C5) o solucion fisiologica a 0,9% (Control) 15 minutos antes de la induccion anestesica. La manutencion anestesica fue hecha con isoflurano hasta la concentracion maxima de 2%. Fueron anotados la PA y la FC antes, con 1 y 5 minutos despues de la induccion y a cada 5 minutos de anestesia. Pacientes a mas de 15 minutos recibiendo isoflurano 2% y que no presentaron PAS menor que 80 mmHg recibieron nitroprusiato de sodio para induccion de la hipotension arterial. RESULTADOS: Tres pacientes (25%) y el grupo C3, un (8%) en el grupo C5 y ocho (66%) en el grupo control necesitaron de nitroprusiato de sodio. La dosis total de nitroprusiato para inducir hipotension arterial en el grupo control fue mayor de que en los grupos C3 y C5 (p < 0,01). La incidencia de complicaciones fue semejante en los tres grupos. CONCLUSIONES: La clonidina por via venosa puede llevar a hipotension arterial inducida en cirugias de timpanoplastia utilizandose tecnica de anestesia balanceada con concentracion de isoflurano limitada en 2%. En las condiciones de este estudio, la clonidina no influencio la calidad anestesica y el tiempo de despertar.

Effects of analgesic intrathecal sufentanil and 0.25% epidural bupivacaine on oxytocin and cortisol plasma concentration in labor patients

BACKGROUND AND OBJECTIVES: Intrathecal sufentanil provides analgesia comparable to epidural local anesthetics for labor pain. Both techniques decrease some parameters of neuroendocrine response to labor pain and both may mitigate reflex oxytocin release in animals. This study aimed to compare the effect of both techniques on cortisol (CPC) and oxytocin (OPC) plasma concentrations in labor patients. METHODS: Participated in this randomized covered study 30 healthy parturients in spontaneous labor with 4-7 cm cervical dilatation. Group S patients received intrathecal sufentanil (10 mg) and group B received epidural 0.25% bupivacaine. Analgesia was assessed by a visual analogue scale and blood oxytocin and cortisol samples were collected before, 30 and 60 minutes after drug administration. Plasma cortisol and oxytocin concentrations were determined by radioimmunoassay. RESULTS: Group S analgesia was more intense at 30 minutes. OPC and CPC before analgesia were similar for both groups. Group S showed a significant decrease in OPC at 60 minutes and in CPC at 30 and 60 minutes (p<0.05), while for Group B such values remained stable throughout the study. CONCLUSIONS: In the conditions of this study, epidural bupivacaine analgesia was associated to stable plasma cortisol and oxytocin concentrations. Conversely, intrathecal sufentanil promoted a more intense analgesia and decreased OPC and CPC.

Efeitos da analgesia do sufentanil por via subaracnóidea e bupivacaína a 0,25% por via peridural sobre as concentrações plasmáticas de ocitocina e cortisol em gestantes em trabalho de parto

BACKGROUND AND OBJECTIVES: Intrathecal sufentanil provides analgesia comparable to epidural local anesthetics for labor pain. Both techniques decrease some parameters of neuroendocrine response to labor pain and both may mitigate reflex oxytocin release in animals. This study aimed to compare the effect of both techniques on cortisol (CPC) and oxytocin (OPC) plasma concentrations in labor patients. METHODS: Participated in this randomized covered study 30 healthy parturients in spontaneous labor with 4-7 cm cervical dilatation. Group S patients received intrathecal sufentanil (10 mg) and group B received epidural 0.25% bupivacaine. Analgesia was assessed by a visual analogue scale and blood oxytocin and cortisol samples were collected before, 30 and 60 minutes after drug administration. Plasma cortisol and oxytocin concentrations were determined by radioimmunoassay. RESULTS: Group S analgesia was more intense at 30 minutes. OPC and CPC before analgesia were similar for both groups. Group S showed a significant decrease in OPC at 60 minutes and in CPC at 30 and 60 minutes (p<0.05), while for Group B such values remained stable throughout the study. CONCLUSIONS: In the conditions of this study, epidural bupivacaine analgesia was associated to stable plasma cortisol and oxytocin concentrations. Conversely, intrathecal sufentanil promoted a more intense analgesia and decreased OPC and CPC.

Clonidina por via venosa na técnica de hipotensão arterial induzida para timpanoplastias

BACKGROUND AND OBJECTIVES Induced arterial hypotension is an effective technique to decrease surgical bleeding. Clonidine is an a2-agonist with central action which was proven to be safe in anesthesia. This study aimed at evaluating the efficacy of intravenous clonidine as the primary drug for induced arterial hypotension. METHODS Participated in this prospective double-blind study 36 patients of both genders, physical status ASA I and II, who were randomly distributed in three groups of 12 patients receiving the following preanesthetic medication 15 minutes before anesthetic induction: 3 microg.kg-1 clonidine (C3), 5 microg.kg-1 clonidine (C5) or 0.9% saline solution (Control). Anesthesia was maintained with isoflurane in a maximum concentration of 2%. BP and HR were recorded before, 1 and 5 minutes after induction and at every 5 minutes of anesthesia. Patients receiving 2% isoflurane for more than 15 minutes and not presenting SBP below 80 mmHg were administered sodium nitroprusside to induce arterial hypotension. RESULTS Sodium nitroprusside was needed in three C3 group patients (25%), one C5 group patient (8%) and eight control group patients (66%). Total nitroprusside dose to induce arterial hypotension in the control group was higher as compared to groups C3 and C5 (p < 0.01). The incidence of complications was similar among groups. CONCLUSIONS Intravenous clonidine may lead to induced hypotension during tympanoplasties under balanced anesthesia with isoflurane concentration limited to 2%. In the conditions of this study, clonidine has not affected anesthetic quality and emergence time.JUSTIFICATIVA Y OBJETIVOS: A hipotension arterial inducida es una tecnica eficaz para diminuir el sangramiento durante actos quirurgicos. La clonidina es un a2-agonista de acion central que ya se mostro segura en anestesia. El objetivo de este estudio fue verificar la eficiencia de la clonidina por via venosa como droga principal en la hipotension arterial controlada. METODO: Participaron del estudio prospectivo y duplamente encubierto, 36 pacientes de ambos sexos, estado fisico ASA I y II, divididos aleatoriamente en tres grupos de 12 pacientes que recibieron medicacion pre-anestesica: clonidina 3 µg.kg-1 (C3), clonidina 5 µg.kg-1 (C5) o solucion fisiologica a 0,9% (Control) 15 minutos antes de la induccion anestesica. La manutencion anestesica fue hecha con isoflurano hasta la concentracion maxima de 2%. Fueron anotados la PA y la FC antes, con 1 y 5 minutos despues de la induccion y a cada 5 minutos de anestesia. Pacientes a mas de 15 minutos recibiendo isoflurano 2% y que no presentaron PAS menor que 80 mmHg recibieron nitroprusiato de sodio para induccion de la hipotension arterial. RESULTADOS: Tres pacientes (25%) y el grupo C3, un (8%) en el grupo C5 y ocho (66%) en el grupo control necesitaron de nitroprusiato de sodio. La dosis total de nitroprusiato para inducir hipotension arterial en el grupo control fue mayor de que en los grupos C3 y C5 (p < 0,01). La incidencia de complicaciones fue semejante en los tres grupos. CONCLUSIONES: La clonidina por via venosa puede llevar a hipotension arterial inducida en cirugias de timpanoplastia utilizandose tecnica de anestesia balanceada con concentracion de isoflurano limitada en 2%. En las condiciones de este estudio, la clonidina no influencio la calidad anestesica y el tiempo de despertar.

Clonidina por vía venosa en la técnica de hipotensión inducida para timpanoplastias

BACKGROUND AND OBJECTIVES Induced arterial hypotension is an effective technique to decrease surgical bleeding. Clonidine is an a2-agonist with central action which was proven to be safe in anesthesia. This study aimed at evaluating the efficacy of intravenous clonidine as the primary drug for induced arterial hypotension. METHODS Participated in this prospective double-blind study 36 patients of both genders, physical status ASA I and II, who were randomly distributed in three groups of 12 patients receiving the following preanesthetic medication 15 minutes before anesthetic induction: 3 microg.kg-1 clonidine (C3), 5 microg.kg-1 clonidine (C5) or 0.9% saline solution (Control). Anesthesia was maintained with isoflurane in a maximum concentration of 2%. BP and HR were recorded before, 1 and 5 minutes after induction and at every 5 minutes of anesthesia. Patients receiving 2% isoflurane for more than 15 minutes and not presenting SBP below 80 mmHg were administered sodium nitroprusside to induce arterial hypotension. RESULTS Sodium nitroprusside was needed in three C3 group patients (25%), one C5 group patient (8%) and eight control group patients (66%). Total nitroprusside dose to induce arterial hypotension in the control group was higher as compared to groups C3 and C5 (p < 0.01). The incidence of complications was similar among groups. CONCLUSIONS Intravenous clonidine may lead to induced hypotension during tympanoplasties under balanced anesthesia with isoflurane concentration limited to 2%. In the conditions of this study, clonidine has not affected anesthetic quality and emergence time.JUSTIFICATIVA Y OBJETIVOS: A hipotension arterial inducida es una tecnica eficaz para diminuir el sangramiento durante actos quirurgicos. La clonidina es un a2-agonista de acion central que ya se mostro segura en anestesia. El objetivo de este estudio fue verificar la eficiencia de la clonidina por via venosa como droga principal en la hipotension arterial controlada. METODO: Participaron del estudio prospectivo y duplamente encubierto, 36 pacientes de ambos sexos, estado fisico ASA I y II, divididos aleatoriamente en tres grupos de 12 pacientes que recibieron medicacion pre-anestesica: clonidina 3 µg.kg-1 (C3), clonidina 5 µg.kg-1 (C5) o solucion fisiologica a 0,9% (Control) 15 minutos antes de la induccion anestesica. La manutencion anestesica fue hecha con isoflurano hasta la concentracion maxima de 2%. Fueron anotados la PA y la FC antes, con 1 y 5 minutos despues de la induccion y a cada 5 minutos de anestesia. Pacientes a mas de 15 minutos recibiendo isoflurano 2% y que no presentaron PAS menor que 80 mmHg recibieron nitroprusiato de sodio para induccion de la hipotension arterial. RESULTADOS: Tres pacientes (25%) y el grupo C3, un (8%) en el grupo C5 y ocho (66%) en el grupo control necesitaron de nitroprusiato de sodio. La dosis total de nitroprusiato para inducir hipotension arterial en el grupo control fue mayor de que en los grupos C3 y C5 (p < 0,01). La incidencia de complicaciones fue semejante en los tres grupos. CONCLUSIONES: La clonidina por via venosa puede llevar a hipotension arterial inducida en cirugias de timpanoplastia utilizandose tecnica de anestesia balanceada con concentracion de isoflurano limitada en 2%. En las condiciones de este estudio, la clonidina no influencio la calidad anestesica y el tiempo de despertar.

Efectos de la analgesia del sufentanil por vía subaracnóidea y bupivacaína a 0,25% por vía peridural sobre las concentraciones plasmáticas de ocitocina y cortisol en embarazadas en trabajo de parto

BACKGROUND AND OBJECTIVES: Intrathecal sufentanil provides analgesia comparable to epidural local anesthetics for labor pain. Both techniques decrease some parameters of neuroendocrine response to labor pain and both may mitigate reflex oxytocin release in animals. This study aimed to compare the effect of both techniques on cortisol (CPC) and oxytocin (OPC) plasma concentrations in labor patients. METHODS: Participated in this randomized covered study 30 healthy parturients in spontaneous labor with 4-7 cm cervical dilatation. Group S patients received intrathecal sufentanil (10 mg) and group B received epidural 0.25% bupivacaine. Analgesia was assessed by a visual analogue scale and blood oxytocin and cortisol samples were collected before, 30 and 60 minutes after drug administration. Plasma cortisol and oxytocin concentrations were determined by radioimmunoassay. RESULTS: Group S analgesia was more intense at 30 minutes. OPC and CPC before analgesia were similar for both groups. Group S showed a significant decrease in OPC at 60 minutes and in CPC at 30 and 60 minutes (p<0.05), while for Group B such values remained stable throughout the study. CONCLUSIONS: In the conditions of this study, epidural bupivacaine analgesia was associated to stable plasma cortisol and oxytocin concentrations. Conversely, intrathecal sufentanil promoted a more intense analgesia and decreased OPC and CPC.