Tranexamic acid reduces the need for allogenic red blood cell transfusions in patients undergoing total hip replacement.

PURPOSE: This prospective randomized double-blind trial evaluates the efficacy of tranexamic acid (TA) to decrease blood losses and red blood cell transfusions in patients undergoing primary unilateral total hip replacement (THR). METHODS: Forty ASA class I to III patients received either iv TA 10 mg.kg(-1) bolus before surgery plus a 1 mg.kg(-1).hr(-1) infusion until wound closure (Group TA) or a placebo (Group P). Red blood cell transfusions were administered according to a standardized protocol. RESULTS: One patient of Group P was excluded because of an erroneous diagnosis at enrollment. Total measured blood losses (Group TA: 1308 +/- 462 mL vs Group P: 1469 +/- 405 mL), preoperative hemoglobin levels (Group TA: 130.4 +/- 12.5 g.L(-1) vs Group P: 131.4 +/- 12.8 vs g.L(-1)), and seven-day postoperative hemoglobin values (Group TA: 97.8 +/- 11.8 g.L(-1) vs Group P: 102.9 +/- 12.2 g.L(-1)) were similar. Autologous whole blood was available in five patients of Group P and seven patients of Group TA. Fewer patients in Group TA required red blood cells (Group TA: 6/20 vs Group P: 13/19; P = 0.026) and allogenic red blood cell transfusions (Group TA: 0/20 vs Group P: 8/19; P = 0.0012). The median number of transfused unit per patient was also significantly less in patients of Group TA (0 unit) than in Group P (2 units; P = 0.03). CONCLUSION: TA did not change measured blood losses but reduced red blood cell transfusion requirements in patients undergoing primary unilateral THR.

The posterior lumbar plexus (psoas compartment) block and the three-in-one femoral nerve block provide similar postoperative analgesia after total knee replacement.

PURPOSE: To compare the efficacy of a continuous posterior lumbar plexus (PSOAS) block to a continuous three-in-one femoral nerve (FEM) block in patients undergoing primary total knee replacement (TKR). METHODS: Sixty patients were randomly allocated to receive iv patient-controlled morphine analgesia (PCA), PCA plus a continuous FEM block with 30 mL ropivacaine 0.5% and epinephrine 1:200,000 bolus followed by an infusion of ropivacaine 0.2% at 12 mL.hr(-1) for 48 hr, or PCA plus a continuous PSOAS block with the same bolus and infusion regimen as the FEM group. Postoperative morphine consumption, verbal analogue scale pain scores at rest and during physiotherapy, and evidence of sensory and motor blockades were noted. RESULTS: Both regional techniques significantly reduced 48 hr morphine consumption (FEM 37.3 +/- 34.7 mg, P = 0.0002; PSOAS 36.1 +/- 25.8 mg, P < 0.0001) compared to PCA (72.2 +/- 26.6 mg). Pain scores at rest, six and 24 hr after TKR were lower in the FEM and PSOAS groups compared to the PCA group (P < 0.0001). Although sensory and motor blockades of the obturator nerve were achieved more often in the PSOAS group than in the FEM group (P < 0.0001), morphine consumption and pain scores did not differ between the two groups. CONCLUSION: Both continuous PSOAS block and continuous three-in-one FEM block provided better analgesia than PCA but no differences were seen between the two regional techniques.

Ropivacaine plasma concentrations are similar during continuous lumbar plexus blockade using the anterior three-in-one and the posterior psoas compartment techniques.

PURPOSE: To compare ropivacaine blood concentrations obtained after a continuous lumbar plexus block performed either by the anterior three-in-one femoral (FEM) technique or the posterior (psoas compartment; PSOAS) technique. METHODS: As a substudy of a larger clinical trial, 24 patients were randomly allocated to receive a bolus of 30 mL of ropivacaine 0.5% plus epinephrine 1:200,000 followed by an infusion of ropivacaine 0.2% at 12 mL.hr(-1) for 48 hr via one of the two continuous lumbar plexus block techniques. Plasma ropivacaine concentrations, up to 48 hr, were measured by high performance liquid chromatography. RESULTS: Mean plasma ropivacaine concentrations were higher in the PSOAS group at 15, 30, and 60 min (two-way analysis of variance, P < 0.0001) but areas under the curve were similar for both groups (FEM 452.4 +/- 253.6 mg.hr(-1).L(-1), PSOAS 433.4 +/- 99.0 mg.hr(-1).L(-1)). Mean maximal plasma concentrations were observed at 48 hr and were comparable for the two techniques (FEM 2630.9 +/- 1470.3 ng.L(-1), PSOAS 2325.1 +/- 604.2 ng.mL(-1)). There was no correlation between blood concentrations at 48 hr and body weight (r2 = 0.085, P = 0.21). One patient in the FEM group achieved a concentration of 6201 ng.mL(-1) at 48 hr. CONCLUSIONS: Although the posterior PSOAS block results in higher early plasma concentrations of local anesthetic than the anterior three-in-one FEM block, both techniques are equivalent with regards to their potential toxicity when a continuous infusion is administered. Local anesthetic accumulation occurs with an infusion of ropivacaine 0.2% at 12 mL.hr(-1) and can lead to potentially dangerous concentrations at 48 hr.

The number of injections does not influence local anesthetic absorption after paravertebral blockade.

PURPOSE: The aims of this study are to determine if the injection of a single large dose of local anesthetics into the paravertebral space increases the risks of inducing toxicity compared with multiple small injections and to describe ropivacaine plasma concentrations resulting from paravertebral blockade. METHODS: Paravertebral blockade was performed using a solution of 10 mL ropivacaine 0.75%, 10 mL lidocaine CO2 2% plus 0.1 mL epinephrine 1:1000 either by a single injection at T3 or T4 (Group S, n = 6) or by five injections of 4 mL each at T2 to T6 (Group M, n = 8). Blood samples were taken at zero, five, ten, 15, 20, 30, 45, 60 and 90 min and at two, three, four, five, six and eight hours. Ropivacaine and lidocaine plasma concentrations were measured by high performance liquid chromatography. RESULTS: Maximal plasma concentrations were comparable for lidocaine: 2.6 +/- 1.3 (S) vs 2.6 +/- 0.8 microg x mL(-1) (M) and for ropivacaine: 1.3 +/- 0.2 (S) vs 1.3 +/- 0.1 microg x mL(-1) (M). Area under the plasma concentration-time curve was higher in Group M for lidocaine: 577.6 +/- 146.1 vs 401.7 +/- 53.2 mg x min(-1) x mL(-1) (P = 0.04) but similar for ropivacaine: 381.1 +/- 95.4 (M) vs 363.1 +/- 85.3 mg x min(-1) x L(-1) (S). CONCLUSIONS: The injection of a single large bolus of local anesthetics into the paravertebral space does not increase its absorption. Maximal ropivacaine plasma concentrations resulting from paravertebral blockade are similar to those reported with equivalent doses of bupivacaine.

Alteraciones nutricias en las enfermedades hepáticas / Nutritive alterations in the liver diseases

La prevalencia y la mortalidad provocadas por la enfermedad hepática grave constituyen un problema relevante de salud. El efecto del factor nutricio en la progresión de la lesión hepática no se ha estudiado con exhaustividad. Las personas con hepatopatía crónica, con frecuencia, sufren de múltiples anormalidades en el metabolismo de las proteínas y de la energía y otro tipo de complicaciones (encefalopatía, sepsis e inmunosupresión). El paciente con enfermedad hepática avanzada, generalmente, presenta desnutrición. Contenido del trabajo: 1) Prevalencia. 2) Patogenia. 3) Recomendaciones: energía; proteínas; proteínas vegetales; hidratos de carbono; lípidos; vitaminas; nutrimentos inorgánicos; zinc; selenio; cobre; hierro. 4) Alimentación enteral y parenteral: fórmulas convencionales de proteínas y aminoácidos; aminoácidos de cadena ramificada; hidratos de carbono y lípidos. 5) Consideraciones nutricias en la falla hepática fulminante

Marcadores serológicos de hepatitis viral / Serum markers in viral hepatitis

En las últimas tres décadas se han desarrollado conocimientos de biología, historia natural y serología que permiten detectar con precisión a los diferentes virus productores de hepatitis viral; gracias a ello es posible detectar el estado agudo o crónico de la infección, los niveles de replicación, la respuesta terapéutca e incluso intuir el pronóstico. Los métodos serológicos habituales son técnicamente sencillos, rápidos y de fácil interpretación. Nuevos avances en biología molecular han permitido la detección de mutantes y serotipos virales diferentes y la determinación de marcadores a niveles genómicos, sugiriendo que estamos en el umbral de una nueva etapa de conocimiento en hepatopatía viral.