Comparación preoperatoria entre pruebas de coagulación y tromboelastografía en pacientes con cirrosis hepática sometidos a trasplante hepático / Thromboelastography and classical coagulation tests in the preoperative period of liver transplantation

Background: Compared to standard coagulation essays (SCE), such as international normalized ratio (INR), prothrombin activated partial thromboplastin time (aPTT), or platelet count, thromboelastograhy (TEG) offers precise and real-time information about hemostasis. TEG tests both platelet function and coagulation by assaying several parameters of clot formation dynamically in whole blood. Aim: To evaluate hemostasis in cirrhotic patients undergoing liver transplantation and determine the positive and negative predictive values of SCE for alterations of TEG. Material and Methods: Preoperative SCE and TEG were prospectively analyzed in 25 patients. Results were categorized as normal, laboratory alteration or clinical alteration. SCE results were compared with TEG parameters to determine positive (PPV) and negative predictive values (NPV). Results: Hemostasis was abnormal and laboratory abnormalities were observed in all patients. One patient had clinical signs of excessive bleeding. SCE were abnormal in all patients and TEG was normal in nine patients. The most common alteration in TEG was hypocoagulability, in some cases associated with hypercoagulability and hyperfibrinolysis. Two patients had solely hypercoagulability. PPV of INR, aPTT, platelet count and fibrinogenemia were 0, 0, 0.5 and 0.17 respectively. NPV of the same tests were 1, 1, 0.34 and 1 respectively. Conclusions: Hypocoagulability was the most common laboratory alteration, however, clinical signs of coagulopathy were rarely present. SCE had a poor predictive value to diagnose o discard hemostatic abnormalities.

Disminución de la presión venosa central: efecto sobre el gasto cardíaco / Reduction of central venous pressure: effect on cardiac output

Introducción: La disminución de la presión venosa central (PVC) a menos de 5mmHg ha sido recomendada para disminuir el sangrado durante la cirugía hepática. No se conoce el efecto de esto en el llenado ventricular e índice cardíaco (IC). Objetivo: Medir el efecto en el volumen de fin de diástole del ventrículo izquierdo indexado (VFDVII) e IC de la disminución a 3-4mmHg de la PVC. Método: Se estudiaron pacientes sometidos a cirugía general en los cuales se monitorizó presión arterial directa, PVC, y ecocardiografía transesofágica (ETE). Posterior a la inducción anestésica, y después de 5min de estabilidad hemodinámica, se midieron VFDVII e IC, los cuales se repitieron 5 min después de disminuir la PVC a 3-4 mmHg. Resultados: Se estudiaron 32 pacientes; 12 cumplían criterios de disfunción diastólica (DD). Los valores basales y posteriores a la reducción de la PVC de VFDVII e IC fueron respectivamente 49,4 ± 13 y 40,1 ±13 ml/m², y 2,8 ± 0,56 y 2,5 ± 0,7 l/m² (ambos p < 0,01). Todas las variaciones fueron mayores en los pacientes con DD. Conclusiones: La disminución de la PVC a los niveles recomendados para disminuir el sangrado produce una moderada pero significativa reducción del IC. Esto debe ser considerado en pacientes con condiciones que pudieran hacer más importante el efecto de la disminución de la PVC.

Introduction: The reduction of central venous pressure (CVP) below 5mmHg has been recommended to decrease bleeding during hepatic surgery. The effect of this practice on cardiac function has not been quantified. Objective: To measure the repercussion of the decrease of CVP on left ventricular end diastolic volume (LVEDV) and cardiac index (CI). Method: Patients undergoing general anaesthesia for major surgery were studied. Monitoring included direct arterial pressure, CVP, and transesophageal echocardiography (TEE). During a stable period of anaesthesia, all of these parameters were measured before and after lowering CVP to 3-4mmHg. Results: Thirty-two patients were studied. Twelve patients met TEE diagnostic criteria for diastolic dysfunction (DD). Basal and post CVP reduction values of LVEDVI and CI were 49.4 ± 13 and 40.1 ±13ml/m², 2.8±0.56 and 2.5±0.7l/m² respectively (both P< .01). All these variations were greater in patients with DD. Conclusions: Reduction of CVP produced a moderate but significant decrease in LVEDV and CI This should be considered in patients with conditions that may increase the effect of decreasing the CVP.

Experiencia clínica con el bloqueador bronquial de ARNDT en pacientes pediátricos / Clinical experience with Arndt bronchial blocker in pediatric patients

Describir la experiencia con el bloqueador bronquial de Arndt (BBA) y determinar los efectos de la ventilación monopulmonar (VMP) en el intercambio gaseoso en pacientes pediátricos. Método: El BBA se utilizó en 11 pacientes que requirieron VMP. Cuando el diámetro del tubo traqueal impedía el uso del BBA como originalmente estaba descrito, éste fue colocado en la tráquea previo a la intubación traqueal quedando por fuera del tubo traqueal. El BBA fue posicionado con ayuda de un fibrobroncoscopio introducido a través del adaptador del bloqueador. Se estandarizaron la modalidad deventilación y las maniobras destinadas a restablecer la oxigenación en caso de desaturación. Se controlaron gases arteriales, presión de vía aérea y CO2 de fin de espiración (EtCO2) ventilando ambos pulmones y en VMP. Resultados: El BBA fue correctamente posicionado en todos los pacientes, obteniéndose un pulmón desinflado en todos ellos. La relación pO2 /FiO2 promedio en decúbito lateral ventilando ambos pulmones y en VMP fue 287 (rango 100-424) y 199 (rango 62-332), p = 0,0108. La diferencia pCO2-EtCO2 mostró un comportamiento variable, aumentando en algunos e incluso haciéndose negativa en otros. Conclusión: El BBA permitió realizar VMP en todos los pacientes. La relación paO2/FiO2 disminuyó en todos los pacientes pero la saturación arterial de oxígeno pudo ser mantenida en niveles seguros. La capnografía mostró ser un indicador poco confiable de la efectividad de la ventilación durante VMP...

Single lung ventilation (SLV) and knowledge of its effects in pediatric patients has been limited by the lack of suitable double lumen tubes (DLT). The bronchial blocker (BB) described by Arndt allows SLV without a DLT, even in small children. Objective: Describe the experience with the Arndt’s BB, and the effects of SLV on gas exchange in children. Design: Observational study. Setting and patients: Eleven children requiring SLV using a BB were studied at a University Hospital. Interventions: A BB was used for SLV. When the internal diameter of the ET didn’t allow the use of the BB as originally described, it was inserted into the trachea before tracheal intubation, leaving the BB next to the ET. A FOB inserted through the multi-portal adapter of the BB guided it to the desired position. Ventilatory pattern and maneuvers to restore arterial oxygen saturation (SatO2) were standardized. Main outcome measures: Arterial blood gases, airway pressure, and EtCO2 were obtained in lateral decubitus position while both lungs were ventilated and during SLV. Results: Ages were between seven months and four years. In 10 patients, the BB was inserted alongside the tracheal tube. In all cases the lung was quiet and deflated. In 2 patients, surgical manipulation dislodged the BB. In one it could not be replaced and thoracotomy was required. Arterial pO2decreased in all patients, but SatO2was maintained above 90%. No significant changes in pCO2 and airway pressure were observed, and pCO2 -EtCO2 relationship was unpredictable. Conclusion: Arndt’s BB allowed SLV in all patients. Even though arterial pO2 decreased in all children, SatO2 could be maintained at an acceptable level...

"Systolic anterior motion"(SAM): una causa infrecuente de hipotensión severa en el perioperatorio de cirugía no cardiaca / Systolic anterior motion: A report of two cases

Background: Systolic anterior motion describes the anterior displacement of one or both mitral valve leaflets, obstructing the outflow tract of the left ventricle. It can be a cause of severe hypotension during the intraoperative and postoperative period of non-cardiac surgery. The diagnosis is made with echocardiography. We report two patients with this problem. The first was a 74-year-old male subjected to an incisional hernia repair who presented severe hypotension in the intraoperative period. A transesophageal echocardiography revealed an anterior displacement of the mitral valve anterior leaflet. Epinephrine was discontinued and Norepinephrine and a volume expander were administered, with good response. The second patient was a 64-year-old male undergoing a right liver lobectomy. In the postoperative period, he suffered severe hypotension. A transesophageal echocardiography revealed an anterior displacement of the mitral valve anterior leaflet. Dobutamine was discontinued, volume was administered, and a Norepinephrine infusion was started with good response.

Aporte de volumen en el perioperatorio: ¿debemos modificar nuestro enfoque? / Transesophageal echocardiography to monitor fluid administration during the perioperative period

Background: During the perioperative period an adequate intravascular volume must be maintained. Current recommendations overestimate perioperative volume requirements. Aim: To compare perioperative volume administration using standard monitoring methods or guided by left ventricular filling parameters. Material and Methods: Twenty-four patients subjected to colon resection were randomized to monitoring by electrocardiography, blood and central venous pressure, or by transesophageal echocardiography. In the latter, volume administration was adjusted to maintain basal values of left ventricular end diastolic volume and cardiac index. Results: Patients with the standard monitoring system and transesophageal echocardiographic monitoring received 21.1±12 and 6.3 ± 2 ml/kg/h of fluids during the perioperative period, respectively (p < 0.01). Conclusions: The use of transesophageal echocardiography significantly reduced the perioperative fluid administration.

Casos clínicos: ecocardiografía transesofágica y monitorización hemodinámica en cirugía no cardiaca / Trans-esophageal echocardiography in non-cardiac surgery: Report of four illustrating cases

Transesophageal echocardiography can assess ventricular filling ana contraction ana detect motility disturbances secondary to ischemia. In non-cardiac surgery it can be extremely helpful to monitor complexpatients. We report a 69-year-old mole subjected to a hepatic lobectomy, a 59-year-old mole with hepatorenal syndrome, a 52-year-old femóle subjected to a gastric bypass, and a 54-year-old mole subjected to a thyroidectomy. In these four cases, left ventricular motility and preload were evaluated with transesophageal echocardiography, and itwas ofgreat aid in decision-making during anesthesia.

Riesgo perioperatorio en pacientes con cirrosis hepática / Perioperative risk among patients with cirrhosis

Ten percent of cirrhotic patients with severely compromised liver function will require a surgical procedure. This article reviews the surgical risk associated with liver damage and surgery. The most important prognostic factor is the degree of functional impairment of the liver. It is evaluated using the Child-Pugh score, which has limitations that have been partially overcome by the Model for End Stage Liver Disease (MELD) score. Cardiac surgery has the highest risk, while extra-thoracic and extra-abdominal procedures have the lowest risk. The mortality for abdominal surgery fluctuates between 11 and 76 percent. Biliary surgery is associated with frequent complications and mortality, which seem to decrease when the procedures are laparoscopic. There are few series that evaluate risk in Child C patients. In liver resective surgery, liver function impairment and magnitude of the excision determine the risk. A high serum creatinine, cardiac failure and emergency surgery are independent risk factors. Although MELD score is useful to predict surgical risk, decision-making must be based on an individualized evaluation of each patient and careful planning of surgical procedures.