RESUMEN
BACKGROUND: The infusion of dextrose in patients receiving epidural and light general anesthesia or general anesthesia alone failed to achieve a positive protein balance. We sought to verify the hypothesis that nutritional supplementation with i.v. amino acids induced a greater protein balance in patients receiving epidural blockade compared with those receiving general anesthesia. METHODS: Sixteen patients were randomly assigned to receive either general anesthesia with desflurane (control group) or general anesthesia combined with epidural analgesia (EDA group). A primed constant infusion of stable isotope tracers L-[1-(13)C]leucine and [6,6-(2)H2]glucose was started after a 32-h fast before surgery, (3 h of fasted state), and continued for 3 h during surgery during which amino acids were infused i.v. (fed state). RESULTS: Compared with the fasted state, the endogenous rate of appearance of leucine decreased to a similar extent in both groups, and protein synthesis increased, with no difference between the two groups. Leucine oxidation did not change in either group. After amino acids infusion, endogenous glucose production remained unchanged and glucose clearance decreased in both groups. Blood glucose, plasma cortisol, serum insulin, and glucagon concentrations increased to the same extent in both groups. CONCLUSIONS: Epidural anesthesia provided no additional benefit beyond the anabolism obtained with amino acids.
Asunto(s)
Anestesia Epidural , Anestesia General , Leucina/farmacocinética , Proteínas/metabolismo , Adulto , Anciano , Presión Sanguínea , Femenino , Glucosa/metabolismo , Frecuencia Cardíaca , Humanos , Infusiones Intravenosas , Leucina/administración & dosificación , Masculino , Persona de Mediana Edad , Proteínas Musculares/metabolismoRESUMEN
BACKGROUND: Net loss of body protein is a prominent feature of the catabolic response to surgical tissue trauma. Epidural analgesia with hypocaloric dextrose has been demonstrated to attenuate leucine oxidation but was unable to make protein balance positive. The current study was set to determine whether an infusion of amino acids on the second day after colon surgery would revert the catabolic state and promote protein synthesis while maintaining glucose homeostasis in patients receiving epidural analgesia as compared with patient-controlled analgesia with morphine (PCA). METHODS: Sixteen patients undergoing colorectal surgery were randomly assigned to receive epidural blockade or PCA as analgesic techniques and underwent a 6-h stable isotope infusion study (3 h fasted, 3 h fed) on the second postoperative day. Whole body glucose kinetics and protein turnover were measured using [6,6-2H2]glucose and l-[1-13C]leucine as tracer. RESULTS: The infusion of amino acids caused a decrease in endogenous glucose rate of appearance in both groups (P < 0.05), with greater changes in the PCA group (P < 0.05). Administration of amino acids suppressed the appearance of leucine from protein breakdown in both groups (P < 0.05), although the decrease was greater in the PCA group (P < 0.05). Leucine oxidation increased in both groups (P < 0.05), with greater change in the epidural group (P < 0.05). Protein synthesis increased to the same extent in both groups (P < 0.05). Protein balance became positive after the infusion of amino acids, and the effect was greater in the PCA group (P < 0.05). CONCLUSIONS: Infusion of amino acids decreased the endogenous glucose production and induced a positive protein balance independent of the type of anesthesia provided, although such effects were greater in the PCA group.
Asunto(s)
Aminoácidos/administración & dosificación , Aminoácidos/uso terapéutico , Analgesia , Cuidados Posoperatorios , Proteínas/metabolismo , Adulto , Anciano , Aminoácidos/farmacocinética , Analgesia Epidural , Anestesia , Análisis de los Gases de la Sangre , Glucemia/metabolismo , Colon/cirugía , Femenino , Gastroscopía , Hormonas/sangre , Humanos , Infusiones Intravenosas , Leucina/sangre , Leucina/farmacocinética , Masculino , Persona de Mediana Edad , Dimensión del Dolor , Ácidos Pentanoicos/sangre , Tamaño de la MuestraRESUMEN
BACKGROUND AND OBJECTIVES: This study was set up to assess whether postoperative suppression of gluconeogenesis by dextrose infusion would be influenced by continuous peripheral nerve block (CPNB) with local anesthetics, in comparison with epidural and with intravenous analgesia. METHODS: Twenty-seven patients, undergoing elective primary total knee arthroplasty for osteoarthritis, were randomly allocated to one of the three groups of 9 patients each: patient controlled analgesia (PCA) with i.v. morphine, epidural with bupivacaine 0.1% and fentanyl 3mug/ml, or continuous femoral and sciatic blocks with ropivacaine 0.2%. Endogenous glucose production, an index of gluconeogenesis, and glucose clearance, an index of whole body glucose uptake, were assessed on the second postoperative day by measuring [6,6-(2)H(2)]glucose kinetics after an overnight fast (fasted state), and during a 3-h period infusion of dextrose at 4 mg/kg/min (fed state). Visual analog scale (VAS) at rest and at knee flexion, use of morphine, mobilization, nutritional intake, and bowel function were also collected. RESULTS: Endogenous glucose production was totally suppressed by 3 h of dextrose infusion in all 3 groups (P < .001) while glucose clearance was unchanged. Blood glucose and insulin increased (P < .001), while glucagon decreased, with the greatest change in the epidural group (P < .05). VAS at rest and at knee flexion was significantly lower in patients receiving epidural and CPNB compared to i.v. morphine (P < .05). Restoration of bowel function, assessed as return of bowel movements, was faster in the CPNB group (P < .05). CONCLUSION: Excellent analgesia was achieved in the epidural and continuous nerve block groups. Postoperative gluconeogenesis was totally suppressed by dextrose infusion independent of the analgesia technique with no change in glucose utilization.