[Techniques to block the sciatic nerve by a lateral approach through the popliteal fossa]. / Técnicas para bloquear el nervio ciático a nivel del hueco poplíteo por vía lateral.

Lateral approaches to the sciatic nerve through the popliteal fossa have recently been described as useful for providing adequate anesthesia and postoperative analgesia for foot and ankle surgery. Numerous publications have appeared on the approach in recent years, proposing new anatomical landmarks to facilitate location of the nerve, reduce the rate of complications, and increase the rate of success. When the lateral popliteal approach has been compared to other approaches to the sciatic nerve, similar success rates have been observed. However, when this technique is used certain factors must be borne in mind because they can influence both latency time and success. This review describes the lateral popliteal approach, its main variations, the factors that can affect latency time or success, and the possibility of providing continuous analgesia. We also sought to compare this approach to other techniques for blocking the sciatic nerve.

Técnicas para bloquear el nervio ciático a nivel del hueco poplíteo por vía lateral / Techniques to block the sciatic nerve by a lateral approach through the popliteal fossa

El bloqueo del nervio ciático a nivel del hueco poplíteopor vía lateral, es una técnica descrita recientemente,que proporciona una adecuada anestesia y analgesiapostoperatoria en la cirugía del pie y del tobillo. En losúltimos años han aparecido numerosas publicacionesrelacionadas con este abordaje, proponiéndose nuevasreferencias para intentar facilitar al anestesiólogo lalocalización del nervio ciático, disminuir las complicaciones,y aumentar el porcentaje de bloqueos exitosos. Elabordaje poplíteo lateral ha sido comparado con otrosabordajes para bloquear el nervio ciático, obteniéndoseporcentajes de éxitos similares. Sin embargo, con elabordaje poplíteo lateral se deben de tener en cuentauna serie de factores que pueden influenciar tanto en lostiempos de instauración del bloqueo como en el porcentajede éxitos.El objetivo de esta revisión es describir el abordajepoplíteo lateral, sus principales variantes, los factoresque pueden influir en el tiempo de latencia o en el porcentajede bloqueos exitosos, la posibilidad de realizartécnicas de analgesia continua, así como compararlo conotros abordajes para bloquear el nervio ciático

Lateral approaches to the sciatic nerve through thepopliteal fossa have recently been described as useful forproviding adequate anesthesia and postoperative analgesiafor foot and ankle surgery. Numerous publicationshave appeared on the approach in recent years, proposingnew anatomical landmarks to facilitate location ofthe nerve, reduce the rate of complications, and increasethe rate of success. When the lateral popliteal approachhas been compared to other approaches to the sciaticnerve, similar success rates have been observed. However,when this technique is used certain factors must beborne in mind because they can influence both latencytime and success.This review describes the lateral popliteal approach,its main variations, the factors that can affect latencytime or success, and the possibility of providing continuousanalgesia. We also sought to compare this approachto other techniques for blocking the sciatic nerve

[Hemodynamic effects of levosimendan following cardiac surgery]. / Efectos hemodinámicos del levosimendan en el postoperatorio de pacientes sometidos a cirugía cardiaca.

The hemodynamic effect of levosimendan was compared to that of dobutamine in a trial enrolling 30 adults undergoing scheduled cardiac surgery with cardiopulmonary bypass. Fifteen patients were randomly assigned to receive levosimendan in a single dose of 18 microg x kg(-1) followed in 15 to 20 minutes by start of infusion at a rate of 0.2 microg x kg(-1) min(-1) for 24 hours (levosimendan group). Another 15 randomized patients received dobutamine infused at a rate of 7.5 microg x kg(-1) min(-1). Hemodynamic parameters were measured before starting infusion of the drug and after 24 hours of treatment. Changes in the main hemodynamic parameters were as follows. In the levosimendan group heart rate (beats/min) was 87.15 (SD 10.22) at baseline and 87.91 (6.00) at 24 hours; mean arterial pressure (mm Hg) was 83.96 (10.57) at baseline and 86.41 (13.29) after 24 hours; cardiac index (L/min/m2) was 2.21 (0.23) at baseline and 2.53 (0.35) at 24 hours; systemic vascular resistance (dyn/sec(-1)/cm(-5)) was 1436.74 (311.48) at baseline and 1378.35 (320.68) at 24 hours. In the dobutamine group heart rate (beats/min) was 84.28 (2.18) at baseline and 96.02 (9.10) after 24 hours; mean arterial pressure (mm Hg) was 83.59 (9.05) at baseline and 74.29 (6.33) at 24 hours; cardiac index (L/min/m2) was 2.16 (0.28) at baseline and) 3.02 (0.34) at 24 hours; systemic vascular resistance (dyn/sec(-1)/cm(-5)) was 1578.93 (334.88) at baseline and 1136.68 (158.60) at 24 hours. We found that mean arterial pressure and both systemic and pulmonary vascular resistance decreased significantly in the levosimendan group (P < 0.05), but not in the dobutamine group. On the other hand, both heart rate and cardiac index increased in the levosimendan group only (P < 0.05). We conclude that levosimendan improves hemodynamic stability in patients who have undergone cardiac surgery and that it is a good alternative for treating postoperative low cardiac output syndrome.

Efectos hemodinámicos del levosimendan en el postoperatorio de pacientes sometidos a cirugía cardiaca / Hemodynamic effects of levosimendan following cardiac surgery

Se compararon 30 pacientes adultos sometidos a cirugía cardiaca programada con circulación extracorpórea al objeto de estudiar el efecto de la dobutamina y levosimendan sobre la hemodinámica. Quince pacientes recibieron levosimendan en dosis bolus de 12 μg kg-1 en 15-20 min seguidos de una infusión de 0,2 μg kg-1 min-1 durante 24 horas (grupo levosimendan). Otros 15 enfermos recibieron una infusión de dobutamina en dosis de 7,5 μg kg-1 min-1. Los parámetros hemodinámicos fueron medidos antes de comenzar la infusión del fármaco y a las 24 horas de tratamiento. La evolución de los principales parámetros hemodinámicos es la siguiente: Grupo dobutamina: Frecuencia cardiaca (latidos /min) 87,15 ± 10,22 (basal) 87,91 ± 6,00 (24 horas); Presión arterial media (mmHg) 83,96 ± 10,57 (basal) 86,41 ± 13,29 (24 horas); Índice cardiaco (l/min/m2): 2,21 ± 0,23 (basal) 2,53 ± 0,35 (24 horas); resistencias vasculares periféricas (dyn seg-1cm-5): 1436,74 ± 311,48 (basal) 1378,35 ± 320,68 (24 horas). Grupo levosimendan: Frecuencia cardiaca (latidos/ min) 84,28 ± 12,18 (basal) 96,02 ± 9,10 (24 horas); Presión arterial media (mm Hg) 83,59 ± 9,05 (basal) 74,29 ± 6,33 (24 horas); Índice cardiaco (l/min/m2): 2,16 ± 0,28 (basal) 3,02 ± 0,34 (24 horas); resistencias vasculares periféricas (dyn seg-1cm-5): 1578,93 ± 334,88 (basal) 1136,68 ± 158,60 (24 horas). Encontramos que las resistencias vasculares y la presión arterial media disminuyen de forma significativa (p<0,05) en el grupo levosimendan, pero no en el grupo dobutamina y que la frecuencia cardiaca y el índice cardiaco aumentan en el grupo levosimendan pero no en el grupo dobutamina. Concluimos que el levosimendan mejora la situación hemodinámica de estos pacientes y es una alternativa en el tratamiento del síndrome de bajo gasto postoperatorio

The hemodynamic effect of levosimendan was compared to that of dobutamine in a trial enrolling 30 adults undergoing scheduled cardiac surgery with cardiopulmonary bypass. Fifteen patients were randomly assigned to receive levosimendan in a single dose of 18 µg.kg-1 followed in 15 to 20 minutes by start of infusion at a rate of 0.2 µg.kg-1min-1 for 24 hours (levosimendan group). Another 15 randomized patients received dobutamine infused at a rate of 7.5 µg.kg-1min-1. Hemodynamic parameters were measured before starting infusion of the drug and after 24 hours of treatment. Changes in the main hemodynamic parameters were as follows. In the levosimendan group heart rate (beats/min) was 87.15 (SD 10.22) at baseline and 87.91 (6.00) at 24 hours; mean arterial pressure (mm Hg) was 83.96 (10.57) at baseline and 86.41 (13.29) after 24 hours; cardiac index (L/min/m2) was 2.21 (0.23) at baseline and 2.53 (0.35) at 24 hours; systemic vascular resistance (dyn/sec-1/cm-5) was 1436.74 (311.48) at baseline and 1378.35 (320.68) at 24 hours. In the dobutamine group heart rate (beats/min) was 84.28 (2.18) at baseline and 96.02 (9.10) after 24 hours; mean arterial pressure (mm Hg) was 83.59 (9.05) at baseline and 74.29 (6.33) at 24 hours; cardiac index (L/min/m2) was 2.16 (0.28) at baseline and) 3.02 (0.34) at 24 hours; systemic vascular resistance (dyn/sec-1/cm-5) was 1578.93 (334.88) at baseline and 1136.68 (158.60) at 24 hours. We found that mean arterial pressure and both systemic and pulmonary vascular resistance decreased significantly in the levosimendan group (P<0.05), but not in the dobutamine group. On the other hand, both heart rate and cardiac index increased in the levosimendan group only (P<0.05). We conclude that levosimendan improves hemodynamic stability in patients who have undergone cardiac surgery and that it is a good alternative for treating postoperative low cardiac output syndromeThe hemodynamic effect of levosimendan was compared to that of dobutamine in a trial enrolling 30 adults undergoing scheduled cardiac surgery with cardiopulmonary bypass. Fifteen patients were randomly assigned to receive levosimendan in a single dose of 18 μg.kg-1 followed in 15 to 20 minutes by start of infusion at a rate of 0.2 μg.kg-1min-1 for 24 hours (levosimendan group). Another 15 randomized patients received dobutamine infused at a rate of 7.5 μg.kg-1min-1. Hemodynamic parameters were measured before starting infusion of the drug and after 24 hours of treatment. Changes in the main hemodynamic parameters were as follows. In the levosimendan group heart rate (beats/min) was 87.15 (SD 10.22) at baseline and 87.91 (6.00) at 24 hours; mean arterial pressure (mm Hg) was 83.96 (10.57) at baseline and 86.41 (13.29) after 24 hours; cardiac index (L/min/m2) was 2.21 (0.23) at baseline and 2.53 (0.35) at 24 hours; systemic vascular resistance (dyn/sec-1/cm-5) was 1436.74 (311.48) at baseline and 1378.35 (320.68) at 24 hours. In the dobutamine group heart rate (beats/min) was 84.28 (2.18) at baseline and 96.02 (9.10) after 24 hours; mean arterial pressure (mm Hg) was 83.59 (9.05) at baseline and 74.29 (6.33) at 24 hours; cardiac index (L/min/m2) was 2.16 (0.28) at baseline and) 3.02 (0.34) at 24 hours; systemic vascular resistance (dyn/sec-1/cm-5) was 1578.93 (334.88) at baseline and 1136.68 (158.60) at 24 hours. We found that mean arterial pressure and both systemic and pulmonary vascular resistance decreased significantly in the levosimendan group (P<0.05), but not in the dobutamine group. On the other hand, both heart rate and cardiac index increased in the levosimendan group only (P<0.05). We conclude that levosimendan improves hemodynamic stability in patients who have undergone cardiac surgery and that it is a good alternative for treating postoperative low cardiac output syndrome

[Comparison of 4 techniques for internal saphenous nerve block]. / Estudio comparativo de 4 abordajes para el bloqueo del nervio safeno interno.

OBJECTIVE: To assess the efficacy of 4 techniques for internal saphenous nerve block with 10 mL of 1.5% mepivacaine. METHODS: Eighty ASA I-II patients scheduled for foot (hallux valgus) surgery with combined sciatic and saphenous nerve blocks were randomized to receive the saphenous nerve block by one of the following techniques: a paravenous approach (n = 20), a transsartorial approach (n = 20), a femoral nerve approach in the inguinal region using a nerve stimulator (n = 20), and by subcutaneous infiltration between the tibial tuberosity and the internal gastrocnemius muscle (n = 20). A pressure cuff was placed 10 cm below the knee of all patients. Success was assessed by pin prick inside the ankle 30 minutes after initiation of the block. Tolerance of the pressure cuff and discomfort during performance of the technique were also assessed. RESULTS: The 4 groups were similar as to distribution of males and females and mean weight, age, and height. Blocking the saphenous nerve by way of the femoral nerve in the inguinal region was the most effective approach (success in 95% of patients), significantly better than the other 3 techniques (P < 0.05). The paravenous approach was successful in 60% of cases, the transsartorial approach in 50%, and the subcutaneous infiltration technique in 45%. The pressure cuff was well tolerated by all patients (100%) in whom the femoral nerve approach was used. The cuff was tolerated by 70% in the paravenous approach group, by 65% in the transsartorial approach group, and by 60% in the subcutaneous infiltration group. Patients reported more discomfort during initiation of the blockade in the paravenous approach and subcutaneous infiltration groups than in the femoral nerve or transsartorial approach groups (P < 0.05). CONCLUSION: The femoral nerve approach in the inguinal region, with nerve stimulator, to block the internal saphenous nerve led to a larger number of successful blocks than did the paravenous or transsartorial approaches, or the technique of subcutaneous infiltration between the tibial tuberosity and internal gastrocnemius muscle.