Postoperative analgesia with continuous wound infusion of local anaesthesia vs saline: a double-blind randomized, controlled trial in colorectal surgery.

AIM: The aim of this prospective double-blind randomized clinical trial was to determine whether preperitoneal continuous wound infusion (CWI) of the local anaesthetic ropivacaine after either laparotomy or video-assisted laparoscopy for colorectal surgery would reduce patient consumption of morphine. METHOD: Patients scheduled for colorectal surgery randomly received a 48-h preperitoneal CWI of either 0.38% ropivacaine or 0.9% saline at rates of 5 ml/h after laparotomy or 2 ml/h after laparoscopy. The primary end-point was total morphine consumption in surgery and afterwards through a patient-controlled analgesia device. Results in the laparotomy and laparoscopy subgroups were also compared. RESULTS: Sixty-seven patients were included, 33 in the ropivacaine CWI group and 34 in the saline group. Median [interquartile range (IQR)] morphine consumption was lower in the ropivacaine group [23.5 mg (11.25-42.75)] than in the saline group [52 mg (24.5-64)] (P = 0.010). Morphine consumption was also lower in the laparotomy subgroup receiving ropivacaine [21.5 (15.6-34.7)] than in the saline group [52.5 (22.5-65) ml] (P = 0.041). Consumption was statistically similar in laparoscopy patients on ropivacaine or saline. No side effects were observed. Sixteen patients had a surgical wound infection (23.9%); 11 (16.4%) presented wound infection and five (7.5%) organ space infection. Forty-six catheter cultures were obtained; 10 (21.7%) were positive, assessed to be due to contamination. CONCLUSION: Preperitoneal CWI of ropivacaine is a good, safe addition to a multimodal analgesia regimen for colorectal surgery. CWI can reduce morphine consumption without increasing adverse effects.

Postoperative respiratory outcomes in laparoscopic bariatric surgery: Comparison of a prospective group of patients whose neuromuscular blockade was reverted with sugammadex and a historical one reverted with neostigmine / Resultados respiratorios postoperatorios en cirugía bariátrica laparoscópica: comparación entre un grupo prospectivo de pacientes cuyo bloqueo neuromuscular fue revertido con sugammadex frente a uno histórico revertido con neostigmina

Purpose. Bariatric surgery patients are at high risk of perioperative respiratory adverse events. We hypothesized that the use of sugammadex to reverse neuromuscular blockade could improve postoperative respiratory outcomes. Methods. Prospective observational series of consecutive patients scheduled for laparoscopic bariatric surgery in whom neuromuscular blockade was reverted with sugammadex were compared with a historical matched cohort of patients reverted with neostigmines. The necessity of postoperative mechanical ventilation or pathological changes in postoperative chest X-ray were two of the comparisons done. Results. We enrolled 160 patients in each group (Sugammadex - SG and Historical - HG). Two patients (mean, CI 95%), (1.25, 0.34-4.4) in the SG and five patients in the HG (mean, CI 95%), (3.13, 1.34-7.11) required mechanical ventilation immediately after surgery (p = 0.38, chi-square test). Significantly less chest X-ray postoperative changes were observed in the SG: 11 patients (6.9%) versus 26 patients (16.3%) in the HG (Odds ratio OR, CI 95%) (0.36, 0.18-0.8). Conclusion. Requirement of mechanical ventilation is not associated to the reversal agent employed. Less pathological postoperative chest X-ray changes were found in the group of patients whose neuromuscular blockade was reverted with sugammadex (AU)

Objetivos. Los pacientes candidatos a cirugía bariátrica presentan mayor riesgo de eventos respiratorios adversos. Nuestra hipótesis fue que la utilización de sugammadex para revertir el bloqueo neuromuscular podría mejorar los resultados postoperatorios desde el punto de vista respiratorio. Métodos. Se comparó una serie prospectiva de pacientes sometidos a cirugía bariátrica laparoscópica revertidos con sugammadex con una cohorte histórica cotejada de pacientes sometidos a la misma cirugía revertidos con neostigmina. Se compararon, entre otros datos, la necesidad de ventilación mecánica postoperatoria y la aparición de cambios radiológicos patológicos tras la operación. Resultados. Se incluyeron 160 pacientes en cada grupo (Sugammadex [SG] e Histórico HG). Dos pacientes (media 1,25%, IC 95% 0,34-4,4) en el SG y 5 en el HG (media 3,13%, IC 95% 1,34-7,11) precisaron ventilación mecánica inmediatamente después de la cirugía (p = 0,38 test chi-cuadrado). Se observaron significativamente menos cambios en la radiografía posoperatoria de tórax en el grupo SG que en el HG: 11 pacientes (6,9%) frente a 26 (16,3%) (odds ratio 0,36, IC 95% 0,18-0,8). Conclusión. Las necesidades de ventilación mecánica no se asocian al agente reversor empleado. Se observaron menos cambios patológicos en la radiografía postoperatoria de tórax en el grupo de pacientes cuyo bloqueo neuromuscular fue revertido con sugammadex (AU)

Postoperative respiratory outcomes in laparoscopic bariatric surgery: comparison of a prospective group of patients whose neuromuscular blockade was reverted with sugammadex and a historical one reverted with neostigmine.

PURPOSE: Bariatric surgery patients are at high risk of perioperative respiratory adverse events. We hypothesized that the use of sugammadex to reverse neuromuscular blockade could improve postoperative respiratory outcomes. METHODS: Prospective observational series of consecutive patients scheduled for laparoscopic bariatric surgery in whom neuromuscular blockade was reverted with sugammadex were compared with a historical matched cohort of patients reverted with neostigmines. The necessity of postoperative mechanical ventilation or pathological changes in postoperative chest X-ray were two of the comparisons done. RESULTS: We enrolled 160 patients in each group (Sugammadex - SG and Historical - HG). Two patients (mean, CI 95%), (1.25, 0.34-4.4) in the SG and five patients in the HG (mean, CI 95%), (3.13, 1.34-7.11) required mechanical ventilation immediately after surgery (p=0.38, chi-square test). Significantly less chest X-ray postoperative changes were observed in the SG: 11 patients (6.9%) versus 26 patients (16.3%) in the HG (Odds ratio OR, CI 95%) (0.36, 0.18-0.8). CONCLUSION: Requirement of mechanical ventilation is not associated to the reversal agent employed. Less pathological postoperative chest X-ray changes were found in the group of patients whose neuromuscular blockade was reverted with sugammadex.

Análisis de los factores de intubación difícil en cirugía bariátrica. Influencia en la elección del bloqueante neuromuscular de la disponibilidad de sugammadex / Analysis of difficult intubation factors in bariatric surgery. Influence of the choice of neuromuscular blocker on the availability of sugammadex

Objetivos. Determinar la incidencia de dificultad de intubación traqueal (DIT) en pacientes obesos operados de cirugía bariátrica y valorar los factores predictivos. El objetivo secundario fue determinar los factores que influyeron en la elección del bloqueante neuromuscular (succinilcolina o rocuronio). Métodos. Estudio observacional, prospectivo en pacientes consecutivos de cirugía bariátrica. Se efectuó la intubación traqueal mediante laringoscopia directa con un tubo traqueal con fiador. Se consideró DIT cuando se observó un grado en la clasificación de Cormack-Lehane III - IV o fue necesario aplicar el algoritmo para DIT (laringoscopia con guía Frova y, en caso de no poder intubar, videolaringoscopio Airtraq). Si con estas medidas no era posible la intubación traqueal, se administró sugammadex en aquellos pacientes con rocuronio y posteriormente se realizó la intubación traqueal con anestesia local y fibroscopio. Resultados. Se incluyó a a 166 pacientes. En un caso se realizó la intubación con fibroscopio. De los 165 pacientes restantes, en 14 pacientes se utilizó la succinilcolina y en 151, el rocuronio. Quince pacientes presentaron DIT (9%): en 4 fue necesario el Airtraq; de ellos, uno requirió sugammadex y fue posteriormente intubado con fibroscopio. La incidencia de intubación con fibroscopio fue del 1,2% (IC 95%; 0,3-4%). La DIT se asoció a los grados de Mallampati 3-4 (odds ratio: 3 [IC 95%; 1,37-6,8], sensibilidad 33%, especificidad 91%) y a la distancia tiromentoniana < 6 cm (odds ratio: 4,8 [IC 95%; 1,45-16]; sensibilidad 53%; especificidad 79%). Conclusión. El protocolo de rescate de DIT con Frova y Airtraq evitó el rescate con sugammadex excepto en un caso (AU)

[Analysis of difficult intubation factors in bariatric surgery. Influence of the choice of neuromuscular blocker on the availability of sugammadex]. / Análisis de los factores de intubación difícil en cirugía bariátrica. Influencia en la elección del bloqueante neuromuscular de la disponibilidad de sugammadex.

OBJECTIVE: To determine the incidence of difficult tracheal intubation (DTI), as well as predictive factors for DTI and what influences the choice of the neuromuscular blocking agent (succinylcholine or rocuronium). METHODS: This is an observational, prospective study on consecutive bariatric surgery patients. Tracheal intubation was performed by direct laryngoscopy with a preformed tracheal tube. DTI was considered when there was a Cormack-Lehane classification of iii-iv or when it was necessary to apply the DTI algorithm, which consisted in the use of Frova guide, and Airtraq video-laryngoscope as second choice, and finally awaking the patient and sugammadex reversal if rocuronium was the selected neuromuscular blocking agent. Thereafter, tracheal intubation was performed using an awake fibroscopic technique RESULTS: One hundred and sixty six patients were included. In one case, conscious fiberscope tracheal intubation was performed. Succinylcholine was selected for 14 patients, and rocuronium for 151 patients. Fifteen patients had a DTI (9%): in 4 Airtraq was deemed necessary. One patient received sugammadex to reverse neuromuscular blockade. Conscious tracheal intubation represented 1.2% (95% CI; 0.3-4%). DTI was associated with Mallampati score of 3-4 (odds ratio, 3 [95% CI; 1.37-6.8], sensitivity of 33%, specificity of 91%) and with thyromental distance<6cm (odds ratio, 4.8 [95% CI; 1.45-16]; sensitivity of 53%; specificity of 79%). CONCLUSION: Rescue airway protocol with Frova and Airtraq avoided the use of sugammadex, except in one patient.

[Influence of the severity of obesity on morbidity and mortality after gastric bypass surgery]. / Influencia del grado de obesidad en la morbimortalidad operatoria de la cirugia bariátrica.

OBJECTIVE: To determine the influence of severity of obesity on morbidity and mortality following Roux-en-Y gastric bypass and vertical ringed gastroplasty, with severity classified as morbid obesity (MO) defined by a body mass index (BMI) between 35 and 55 Kg/m2 and super-morbid obesity (SMO) defined by a BMI exceeding 55 Kg/m2. METHOD: A series of patients who underwent the aforementioned type of gastric bypass surgery were followed for 5 years. The patients were classified as to whether they had associated sleep apnea syndrome, alveolar hypoventilation, or "overlap syndrome". RESULTS: A total of 105 patients were enrolled: 70 (66.7%) classified as having MO and 35 (33.3%) classified as having SMO. Distribution by sex was significantly different in the 2 groups, but respiratory diseases were similar. PaO2 was higher in the MO group, PaCO2 was lower, and the alveolar-arterial gradient was smaller. Duration of surgery was shorter in the MO group (120.43 +/- 32.97 vs. 136.76 +/- 28.28 minutes). The percentage of complications was similar in the 2 groups (32.86% and 45.7% in the MO and SMO groups, respectively), although the incidence of respiratory complications was higher in SMO patients (8.57% vs. 20% in the MO and SMO groups, respectively). No differences were observed in the rates of surgical, hemodynamic, or infectious complications. Length of hospital stay was similar (6.44 vs. 6.69 for MO and SMO patients, respectively). CONCLUSIONS: More severe obesity can be associated with preoperative arterial blood gas alterations in patients with concomitant respiratory disease and a higher incidence of respiratory complications in the early phase of recovery from gastric bypass surgery.

[Hemodynamics of the cirrhotic patient during liver transplantation. Influence of the preservation of portal and vena cava flow]. / Hemodinamia del paciente cirrótico durante el trasplante hepático. Influencia de la preservación del flujo portal y de la vena cava.

OBJECTIVE: To describe the hemodynamic pattern of patients undergoing liver transplantation with preservation of portocaval flow. PATIENTS AND METHODS: A prospective study of 20 cirrhotic patients who had not previously undergone surgery for portal hypertension or had porto-systemic bypass, both of which have hemodynamic effects in the cirrhotic patient. The patients were transplanted with preservation of inferior vena cava flow and temporary portocaval shunt. RESULTS: The decrease in cardiac output during the anhepatic phase was only 10% and mean blood pressure (77.6 +/- 11 versus 76 +/- 10 mm Hg) and supply pressures (central venous pressure 9.1 +/- 5.5 versus 8.4 +/- 5.3 mm Hg; pulmonary capillary pressure 11.4 +/- 6.1 versus 11.3 +/- 7.4 mm Hg) remained stable. Likewise, no significant increase in systemic vascular resistance (614 +/- 223 versus 676 +/- 306 dyne-sec/cm5) or heart rate (90 +/- 14 versus 97 +/- 17 beats/min). The number of units of packed red cells was 2.7 +/- 2.5 and 35% of the patients required no transfusions. Diuresis was stable throughout the procedure (total diuresis 3.6 +/- 2.4 mL/Kg/h; anhepatic phase 1.3 +/- 1.5 mL/Kg/h). CONCLUSIONS: Creation of a portocaval shunt during the anhepatic phase of liver transplantation allows hemodynamic vital signs to be held stable, decreases the need for transfusion and maintains diuresis.

Hemodinamia del paciente cirrótico durante el trasplante hepático. Influencia de la preservación del flujo portal y de la vena cava / Hemodynamics of the cirrhotic patient during liver transplantation: the effect of preserving portocaval flow

OBJETIVO: Describir el patrón hemodinámico de aquellos pacientes sometidos a trasplante hepático con preservación de flujo caval y portal. PACIENTES Y MÉTODOS: Estudio prospectivo de un grupo de 20 pacientes cirróticos, sin cirugía de la hipertensión portal o derivación portosistémica previa que influya en la hemodinámica del paciente cirrótico, trasplantados según la técnica de preservación de vena cava inferior asociándose anastomosis porto-cava temporal. RESULTADOS: La disminución del gasto cardíaco durante la fase anhepática fue tan sólo del 10 por ciento, manteniéndose estables tanto la presión arterial media (77,6 ñ 11 frente a 76 ñ 10 mm Hg) como las presiones de llenado (presión venosa central: 9,1 ñ 5,5 frente a 8,4 ñ 5,3 mm Hg; presión capilar pulmonar: 11,4 ñ 6,1 frente a 11,3 ñ 7,4 mm Hg). Asimismo no hubo un aumento significativo de las resistencias vasculares sistémicas (614 ñ 223 frente a 676 ñ 306 dinas-s/cm5) ni de la frecuencia cardíaca (90 ñ 14 frente a 97 ñ 17 latidos/min). El requerimiento de concentrados de hematíes fue de 2,7 ñ 2,5 pudiéndose trasplantar el 35 por ciento de los pacientes sin transfusión. La diuresis se mantuvo estable a lo largo del trasplante (diuresis total: 3,6 ñ 2,4 ml/Kg/h; fase anhepática: 1,3 ñ 1,5 ml/Kg/h). CONCLUSIONES: la realización de una anastomosis porto-cava durante la fase anhepática del trasplante hepático permite mantener la estabilidad hemodinámica, así como disminuir los requerimientos transfusionales y mantener la diuresis (AU)

La resección es un buen tratamiento del hepatocarcinoma sobre el hígado cirrótico en pacientes seleccionados / Resection is an effective treatment for hepatocarcinoma in selected cirrhotic patients

Introducción. La resección quirúrgica del hepatocarcinoma sobre cirrosis es una indicación discutida debido a su alta morbilidad y recidiva tumoral. No obstante, debido a la edad de presentación del tumor y el alargamiento de las listas de espera de trasplante, es la única alternativa para muchos pacientes. El objetivo de este estudio es analizar la supervivencia, recidiva y factores pronóstico de la resección del hepatocarcinoma en pacientes seleccionados. Pacientes y métodos. Se analizó una serie de 53 pacientes con cirrosis durante un período de 11 años a los que se realizó una resección hepática por hepatocarcinoma. Se intervinieron 45 varones y 8 mujeres con una edad media de 65,4 (8,4 años). Se indicó la cirugía en tumores de 5 cm o menores, con función hepática óptima y sin evidencia de hipertensión portal. En el 55 por ciento de los casos se realizó una segmentectomía, en el 36 por ciento bisegmentectomía y en el 9 por ciento una resección hepática mayor. Resultados. La mortalidad perioperatoria fue del 2 por ciento. Se confirmó que la presencia de hipertensión portal está directamente relacionada con la aparición de descompensación ascítica y la mortalidad a los 12 meses. La supervivencia fue del 86, el 64 y el 59 por ciento al año, tres y 5 años respectivamente, objetivando que la biloburidad, los nódulos satélite y la ausencia de cápsula son factores de mal pronóstico. La tasa de recidiva fue del 17, el 42 y el 60 por ciento a uno, tres y 5 años, siendo los nódulos satélite y la invasión vascular micro y macroscópica factores directamente relacionados con la recidiva. Conclusiones. La resección es un buen tratamiento del hepatocarcinoma sobre hígado cirrótico en pacientes seleccionados (AU)

[Changes in the bispectral index and the spectral edge frequency 90 during different phases of anesthesia with sevoflurane]. / Cambios del índice biespectral y del límite espectral 90% (LE90) en las distintas fases de la anestesia con sevoflurano en la cirugía abdominal.

INTRODUCTION: Electroencephalographic monitoring is one of the techniques used to measure hypnosis during anesthesia. Efforts to find a means to apply this monitoring function are justified by cases of intraoperative awakening and are in the interest of guaranteeing patient welfare and controlling anesthesia. OBJECTIVES: To determine the changes in two electroencephalographic parameters, the bispectral index (BIS) and the spectral edge frequency 90 (SEF90), during the different phases of anesthesia. Patients and method. Forty-eight patients undergoing abdominal surgery were studied prospectively. Anesthesia was induced by propofol, fentanyl or sevoflurane. Anesthesia was maintained with sevoflurane and O2/N2O at a concentration of 70% to maintain BIS between 40 and 60. Variables monitored were heart rate, blood pressure, arterial oxygen saturation (with a pulse oximeter), expired CO2 partial pressure, inspired and expired sevoflurane partial pressure, esophageal temperature, SEF90 (defined as the frequency below which 90% of the power in the electroencephalogram resides) and BIS. All variables were recorded during three phases: induction, maintenance and recovery from anesthesia. We then performed an analysis of variance, with p < 0.05 considered significant. RESULTS: During induction mean BIS decreased from 95.6 to 34.7 after intubation, while SEF90 fell from 20.5 Hz to 11.9 Hz. During maintenance BIS, SEF90 and expired sevoflurane partial pressure remained constant. During recovery mean BIS increased from 59.2 to 92.3 upon extubation, and SEF90 went from 15.1 to 22.2 Hz; although heart rate increased, blood pressure did not. The mean electroencephalographic values recorded when movement occurred were 77 for BIS (range 58-96) and 18 for SEF90 (range 13-18). CONCLUSION: Electroencephalographic monitoring is useful for distinguishing between states of consciousness and unconsciousness during anesthesia, and is valid for the phases of induction and recovery. BIS values over 58 and SEF90 values over 13 may indicate inadequate hypnosis.

Cambios del índice biespectral y del límite espectral 90 por ciento (le90) en las distintas fases de la anestesia con sevoflurano en la cirugía abdominal / Changes in the bispectral index and the spectral edge frequency 90 during different phases of anesthesia with sevoflurane

INTRODUCCIÓN. La monitorización electroencefalográfica es uno de los métodos utilizados como medida de la hipnosis durante la anestesia. La búsqueda de un monitor con esta función se justifica por los casos de despertar intraoperatorio y para ofrecer al paciente garantías de bienestar y control. OBJETIVOS. Determinar los cambios en los valores de dos parámetros electroencefalográficos, el índice biespectral (BIS) y del límite espectral 90 por ciento (LE90), durante las distintas fases del acto anestésico. PACIENTES Y MÉTODO. Se estudiaron de forma prospectiva 48 pacientes intervenidos de cirugía abdominal. La inducción anestésica se realizó con propofol, atracurio, fentanilo y sevoflurano. El mantenimiento anestésico se realizó con sevoflurano y O2/N2O al 70 por ciento con el objetivo de mantener un valor de BIS entre 40-60. Se monitorizó la frecuencia cardíaca, la presión arterial, la pulsioximetría, la fracción espirada de CO2, la fracción inspirada y espirada de sevoflurano, la temperatura esofágica cl LE90 (frecuencia espectral que deja por debajo el 90 por ciento de la potencia del electroencefalograma) y el BIS. Las variables fueron analizadas en tres fases: la inducción, el mantenimiento y la recuperación anestésica. El análisis estadístico se realizó mediante el análisis de la variancia y se consideró significativa una p < 0,05. RESULTADOS. En la fase de inducción los valores medios del BIS pasaron de 95,6 a 34,7 después de la intubación, y los de la LE90 de 20,5 a 11,9 Hz. En la fase de mantenimiento anestésico, los valores del BIS y de la LE90 y de la fracción espirada de sevofluorano se mantuvieron constantes. En la fase de recuperación el BIS pasó desde valores medios de 59,2 a 92,3 en la extubación, y la LE90 de 15,1 a 22,2 Hz; la frecuencia cardíaca aumentó, pero no la presión arterial. Los valores electroencefalográficos medios registrados durante la aparición de movimiento fueron para el BIS de 77 con un rango de 58 a 96 y para la LE90 de 18 con un rango de 13 a 18.CONCLUSIÓN. La monitorización electroencefalográfica es útil para diferenciar la situación de consciencia-inconsciencia durante el acto anestésico, lo cual es válido para la inducción anestésica y para la fase de recuperación anestésica. Valores del BIS por encima de 58 y de la LE90 por encima de 13 pueden indicar una inadecuada hipnosis (AU)

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[Percutaneous femoro-porto-jugular venovenous shunt in orthotopic liver transplantation]. / Derivación venovenosa percutánea fémoro-porto-yugular en el trasplante ortotópico de hígado.

Veno-venous bypass (VVB) by the percutaneous introduction of cannulas in the right internal jugular vein during liver transplantation may reduce the complications derived from the classical method of axillary vein dissection. The results and complications observed over a two and a half year period in 126 consecutive patients submitted to liver transplantation in whom preparation for femoral-portal-jugular veno-venous bypass was carried out are reported. Twelve complications (9.5%) were observed in the 126 patients. All the complications were due to jugular cannulation and were divided as follows: in 7 patients (5.5%) some of the guide introductions were unsuccessful following multiple punctures; in 2 patients (1.6%) the right carotid artery was punctured; 2 hemothorax (1.6%) were observed and one pneumothorax (0.8%). Forty patients required veno-venous bypass. The blood flows obtained during VVB were suffice in all the cases with a mean +/- standard deviation of 2.21 +/- 0.44 l/min-1. The technique of femoral-portal-jugular veno-venous bypass is a good alternative to the classical method of the axillary approach. It has advantages such as in the speed of installation of VVB and the utility of the large jugular vein during the remainder of the surgery for rapid fluid transfusions. Although the number of complications is low, they may be important thereby hindering intra management and post operative of the patients.

[Comparative study between continuous and bolus subarachnoid administration of 2% lidocaine]. / Estudio comparativo entre la administración subaracnoidea continua o en bolos de lidocaína al 2%.

OBJECTIVE: To compare anesthesia with lidocaine 2% by bolus or by continuous perfusion through a subarachnoid catheter. PATIENTS AND METHODS: Thirty-one patients undergoing surgery on a lower limb were studied prospectively. Patients were divided into two groups: 14 received subarachnoid anesthesia in continuous perfusion (group CP) while 17 were given subarachnoid anesthesia in bolus form (group B). An 18G Tuohy needle was used with a 20 G catheter. An initial bolus of 20 mg (1 ml) was administered in group CP and followed by continuous perfusion at a rate of 16 mg/h (0.8 ml/h). In group B an initial 20 mg bolus was followed by additional ones of 10 mg (0.5 ml). The optimum sensory level was T 10. RESULTS: The two groups were homogeneous with respect to age, weight, height and medical history. Fewer boluses were needed with continuous perfusion. Seven patients (50%) in group CP required additional boluses. The ratio of total drug dose administered in mg to time of surgery was significantly higher in group CP. The sensory and motor blockade levels obtained were similar in the two groups. One case of hypotension and one of bradycardia were recorded. Two cases of minor headache were recorded in group B. Sedation was used in 7 patients (50%) in group CP and in 13 (76%) in group B. CONCLUSION: Subarachnoid administration of lidocaine 2% in continuous perfusion affords the same sensory and motor blockade as administration in bolus form and does not reduce the overall amount of lidocaine used.

[Utilization of veno-venous bypass in orthotopic liver transplantation]. / Utilización de derivación venovenosa en el trasplante ortotópico de hígado.

AIMS: The aim of the present study was to evaluate the hemodynamic effects of venovenous bypass (VVB) and its possible protective action during the clamping of the hepatic vessels carried out in the anhepatic phase of the orthotopic liver transplantation. PATIENTS AND METHODS: Forty-one liver transplant patients, 15 of whom were operated with VVB, were studied. VVB consisted of a bridge from the primitive iliac veins and the portal vein to the left axillary vein. The hemodynamic, metabolic and biologic variables as well as the components of reposition and the drugs administered were measured. The results obtained in both groups were statistically compared and analyzed. RESULTS: During the anhepatic phase the values of cardiac output did not modify in the patients operated with VVB, while these values significantly decreased in other patients. Peripheral resistances increased less in the VVB group. During the reperfusion phase there were no significant differences between the hemodynamic parameters of either group. The decrease in temperature during the anhepatic phase was significantly greater in the VVB group. CONCLUSIONS: Venovenous bypass offers greater hemodynamic stability during the anhepatic phase of orthotopic liver transplantation.

[Usefulness of pulse oximetry in thoracic surgery]. / Utilidad de la pulsioximetría en cirugía torácica.

Saturation of hemoglobin in arterial blood was simultaneously measured by co-oximetry (SaO2) and by pulse oximetry (SpO2) in 228 samples from 42 patients undergoing general anesthesia for thoracic surgery. Data was referred to SaO2 obtained with arterial catheterization. We found a significant correlation (r: 0.949 and p less than 0.001) and the mean differences were 0.77 +/- 1.84. The correlation between PaO2 and the difference among both methods was significantly negative (r: -0.20; p less than 0.001). Although there was a significant correlation, the method loses reliability and accuracy in patients with hypoxemia. In these patients oximetric values are slightly lower than those obtained with arterial cannulation. We emphasize the clinical usefulness of this technique since it is instantaneous and allowed immediate therapeutic actions.