Analgesia, sedación y anestesia para cateterismo diagnóstico y/o terapéutico en pacientes pediátricos con cardiopatías congénitas en el Hospital Clínico de la Pontificia Universidad Católica de Chile: algunas recomendaciones / Analgesia, sedation and anesthesia in diagnostic or therapeutic catheterization in pediatric patients with congenital heart disease

Las presentes recomendaciones han sido elaboradas en base a nuestra experiencia, con el propósito de entregar algunas pautas sobre analgesia, sedación y anestesia para cateterismos diagnósticos y/o terapéuticos en pacientes pediátricos con cardiopatías congénitas, de acuerdo a la clasificación de riesgo de los mismos. El propósito de ésta es contribuir a disminuir la incidencia de eventos adversos asociados a morbilidad y mortalidad.

Recommendations based con clinical experience with analgesia, sedation and anesthesia in diagnostic or therapeutic cardiac catheterization in pediatric patients with congenital heart disease are outlined. These recommendations, based on clinical experience at a single institution (Catholic University Hospital in Santiago, Chile) are intended to help reduce de incidence of adverse effects, morbidity and mortality in this patient population.

Aortic stenosis and acquired von Willebrand disease: lack of association.

OBJECTIVES: The association between aortic stenosis (AS) and acquired von Willebrand disease type 2A has been described. It may be present in up to 90% of patients with AS. Shear stress has been proposed as the underlying mechanism; however, the physiopathology of this condition is not completely understood. No specific treatment has been studied in this specific population besides aortic valve replacement (AVR). As a coadjuvant therapy, some cardiac surgery centers use desmopressin routinely. The authors report the first stage of an ongoing study designed to compare the effects of desmopressin versus placebo in patients with severe AS scheduled for AVR. Because of the different incidences of the acquired von Willebrand type 2A reported in the literature, the first stage was conducted to describe the incidence of this clinical association in the present population, allowing the sample size for the second stage of the study to be obtained. DESIGN: A prospective cohort study. SETTING: A single academic medical center. PARTICIPANTS: Thirteen patients with severe AS scheduled for AVR. INTERVENTION: None. MEASUREMENTS AND MAIN RESULTS: Patients with severe AS scheduled for AVR were studied preoperatively with a von Willebrand laboratory panel. Results were negative for acquired von Willebrand disease type 2A in all patients. The second stage of the trial was stopped. CONCLUSION: Contrary to previous reports, no correlation was found between AS and acquired von Willebrand disease type 2A. Further studies are needed to ascertain whether this lack of association is caused by a specific characteristic of the present population, the small sample size, or other factors.

Reparación endovascular de aneurisma aórtico abdominal: estudio piloto de endoprótesis Ovation™: resultados comparativos / Endovascular repair of abdominal aortic aneurysm: comparative results of a pilot study using the Ovation™ prosthesis

Introducción: Las endoprótesis actuales para tratar aneurismas aórticos (AAA) requieren introductores de alto diámetro (18-25F) y se sustentan excluyendo el aneurisma, mediante la fuerza radial de stents metálicos. Objetivo: prótesis Ovation™ (TriVascular, EEUU) con aquellas disponibles en el mercado. Material y Método: Entre Noviembre 2009 y Agosto 2010 tratamos 47 AAA. En 10 pacientes usamos Ovation™ (Grupo 1). Grupo Control (2): diez pacientes tratados contemporáneamente con endoprótesis comerciales. Ovation™ es tri-modular, de PTFE y nitinol con un stent barbado para fijación supra-renal. Sella bajo las arterias renales mediante 2 anillos llenados con un polímero durante el implante. Usa introductor 13-15F. Usa-Philips-Allura (Best, Holanda). Comparamos: duración del procedimiento, hospitalización y complicaciones. Utilizamos test de Fisher exacto y t de student no pareado. Resultados: Éxito técnico 100 por ciento. Sin diferencia entre grupos (edad, sexo, tamaño AAA, riesgo ASA, laboratorio preoperatorio). Tiempo operatorio (hrs): 2,12 +/- 0,7 vs. 2,0 +/- 0,6 (NS). Estadía postoperatoria (hrs): 44,5 +/- 10,7 vs 49,5 +/- 32,0 (NS). El cuello del AAA y la permanencia en UTI fueron más cortos en grupo 1 (p= 0,035 y 0,0451). Seguimiento (4,5-12 meses) sin eventos adversos, endofugas tipo I ni III, ni re-intervenciones. Conclusiones: Los resultados con Ovation™ a corto plazo son comparables con los de otras endoprótesis, cumpliendo con estándares de eficacia y seguridad. Ovation ™ navega por vasos pequeños, permite un despliegue preciso y sellado efectivo en cuellos > 7 mm, ampliando el tratamiento endovascular del AAA.

Background. Current endografts used in treatment of abdominal aortic aneurysm (AAA), use large (18-25F) delivery systems. Graft fixation and aneurysm sealing is obtained by a proximal stent, requiring an aortic neck >15 mm. Objective. To compare the efficacy and safety of Ovation™ endograft (TriVascular, USA) with standard endografts. Methods. Between November 2009 and August 2010 we treated 47 AAA. In 10 patients we used Ovation™ (Group 1). Ten patients treated during the same period with commercially available endografts were used as controls (Group (2). The Ovation™ endo-prosthesis is tri-modular, made of PTFE andnitinol with low profile (13-15F) and has a barbed suprarenal stent for fixation. Sealing is obtained independently through 2 inflatable rings filled with a biocompatible polymer during the procedure. Implantation followed the standard procedure through femoral exposure, using the Philips Allura imaging equipment (Best, Netherlands). Procedure duration, length of stay (LOS) and complications were compared between groups. Fisher exact test and unpaired Student’s t test were used for comparisons. Results. Results. Technical success was 100 percent. We observed no difference between groups (age, sex, AAA size, ASA risk, preoperative lab work). Procedure time (hrs) was 2,12 +/- 0,7 vs. 2,0 +/- 0,6 (NS), LOS (hrs) was 44,5 +/- 10,7 vs. 49,5 +/- 32,0 (NS) in Groups 1 and 2, respectively. Aneurysm neck length and ICU stay were shorter in Group 1 (p= 0,035 and 0,0451 respectively). During a 12 month follow up no adverse events, type I or III endoleak, or secondary interventions have occurred. Conclusion. Results with Ovation™ are comparable to other endografts currently available, achieving the same standards of efficacy and safety. Its highly flexible delivery system allows navigation through small vessels, easy deployment and effective sealing of AAA with necks > 7 mm, broadening the span of patients suitable for endovascular treatment.

Decreased nitric oxide products in the urine of patients undergoing cardiac surgery.

OBJECTIVE: Renal vasoconstriction has been blamed as a cause of perioperative renal dysfunction after cardiac surgery. Endothelial function is a critical determinant of vascular tonus, including vasoconstriction. The objective of this study was to establish whether the release of the endothelial vasodilator nitric oxide (NO) or NO products is altered in patients undergoing surgery with cardiopulmonary bypass in 3 different clinical conditions. DESIGN: Observational and randomized prospective study. SETTING: University hospital. PARTICIPANTS: Adults and pediatric patients undergoing elective cardiac surgery with cardiopulmonary bypass. INTERVENTIONS: Three groups of patients were studied: group 1, 10 patients undergoing elective coronary artery surgery; group 2, 20 patients undergoing elective coronary artery surgery randomized to 2 hematocrit values during cardiopulmonary bypass, high (27%) and low (23%); and group 3, 10 pediatric patients undergoing surgical repair of noncyanotic cardiac defects. MEASUREMENTS AND MAIN RESULTS: NO products (NO2 + NO3) and cyclic guanosine monophosphate (cGMP) in urine were measured before, during hypo- and normothermic cardiopulmonary bypass, and 1 hour postoperatively. Filtration fraction was calculated. The glomerular filtration rate and effective renal plasma flow were measured with inulin and (131)I-hippuran clearances, respectively. Urinary alpha glutathione s-transferase was measured pre- and postoperatively in groups 1 and 3. NO products, as well as cGMP, decreased significantly during hypo- and normothermic cardiopulmonary bypass in all groups. This was not because of urine dilution or the degree of hemodilution. Age did not appear to alter this response. Filtration fraction decreased during cardiopulmonary bypass. Alpha glutathione s-transferase was normal pre-and postoperatively. CONCLUSIONS: Cardiac surgery with cardiopulmonary bypass is associated with a significant decrease of NO products. In the absence of kidney damage, decreased NO products could represent a physiologic response to cardiopulmonary bypass; however, endothelial dysfunction cannot be excluded.

[Renal function during cardiac surgery with extracorporeal circulation]. / Función renal en cirugía cardíaca con circulación extracorpórea: Pacientes valvulares y coronarios.

BACKGROUND: Patients with valvular heart disease are at high risk of acute renal failure after surgery with extracorporeal circulation. AIM: To describe changes in renal function parameters during surgery with extracorporeal circulation in patients with valvular heart disease and compare them with those found in patients undergoing elective coronary surgery. MATERIAL AND METHODS: Two groups of patients were studied. Group 1 was composed by twelve patients undergoing elective coronary surgery and group 2 was composed by eleven patients undergoing surgery for heart valve replacement. Glomerular filtration rate and effective renal plasma now were estimated from inulin and the 131 I-hippuran clearance respectively, at five different times, during surgery and the postoperative period. Sodium filtration fraction and fractional excretion were calculated. Alpha and pi-glutathione s-transferase in urine were measured as markers of tubular damage in the pre and postoperative periods. RESULTS: Effective renal plasma flow was reduced in both groups before induction of anesthesia, did not change during surgery and decreased significantly in patients with valvular disease in the postoperative period. Glomerular filtration rates were normal during all the study period. There was a non significant reduction of filtration fraction during extracorporeal circulation. Alpha and pi glutathione s-transferases were normal and did not change. Fractional excretion of sodium increased significantly postoperatively. CONCLUSIONS: In patients with valvular disease undergoing surgery with extracorporeal circulation, renal function does not deteriorate. No significant difference was found when compared with patients undergoing coronary surgery. No evidence of functional and cellular renal disfunction or damage was found in both study groups.

Función renal en cirugía cardíaca con circulación extracorpórea: Pacientes valvulares y coronarios / Renal function during cardiac surgery with extracorporeal circulation

Background: Patients with valvular heart disease are at high risk of acute renal failure after surgery with extracorporeal circulation. Aim: To describe changes in renal function parameters during surgery with extracorporeal circulation in patients with valvular heart disease and compare them with those found in patients undergoing elective coronary surgery Material and Methods: Two groups of patients were studied. Group 1 was composed by twelve patients undergoing elective coronary surgery and group 2 was composed by eleven patients undergoing surgery for heart valve replacement. Glomerular filtration rate and effective renal plasma now were estimated from inulin and the 131 I-hippuran clearance respectively, at five different times, during surgery and the postoperative period. Sodium filtration fraction and fractional excretion were calculated. Alpha and pi-glutathione s-transferase in urine were measured as markers of tubular damage in the pre and postoperative periods. Results: Effective renal plasma flow was reduced in both groups before induction of anesthesia, did not change during surgery and decreased significantly in patients with valvular disease in the postoperative period. Glomerular filtration rates were normal during all the study period. There was a non significant reduction of filtration fraction during extracorporeal circulation. Alpha and pi glutathione s-transferases were normal and did not change. Fractional excretion of sodium increased significantly postoperatively Conclusions: In patients with valvular disease undergoing surgery with extracorporeal circulation, renal function does not deteriorate. No significant difference was found when compared with patients undergoing coronary surgery. No evidence of functional and cellular renal disfunction or damage was found in both study groups.

Anestesia y cirugía en revascularización coronaria en un paciente trasplantado cardiaco: reporte de un caso / Anesthesia and coronary revascularization surgery in a cardiac transplanted patient: a case report

Dado el aumento de la sobrevida de los pacientes trasplantados cardiacos es cada vez más frecuente que se sometan a otras cirugías, tanto cardíacas, como no cardíacas. En este artículo se presenta un caso clínico de un paciente trasplantado cardíaco sometido a una cirugía de revascularización coronaria, y posteriormente una revisión de la literatura y discusión del caso.

[Endovascular repair of abdominal aortic aneurysm. Results in 80 consecutive patients]. / Tratamiento endovascular de aneurisma aórtico abdominal: resultados en 80 pacientes consecutivos.

BACKGROUND: Endovascular repair of abdominal aortic aneurysms (AAA) avoids laparotomy, shortens hospital stay and reduces morbidity and mortality related to surgical repair, allowing full patient recovery in less time. AIM: To report short and long term results of endovascular repair of AAA in 80 consecutive patients treated at our institution. PATIENTS AND METHODS: Between September 1997 and February 2005, three women and 77 men with a mean age 73.6+/-7.7 years with AAA 5.8+/-1.0 cm in diameter, were treated. The surgical risk of 38% of patients was grade III according to the American Society of Anesthesiologists classification. Each procedure was performed in the operating room, under local or regional anesthesia, with the aid of digital substraction angiography. The endograft was deployed through the femoral artery (83.7% bifurcated, 16.3% tubular graft). A femoro-femoral bypass was required in 11.3% of cases. Follow-up included a spiral CT scan at 1, 6 and 12 months postoperatively, and then annually. RESULTS: Endovascular repair was successfully completed in 79/80 patients (98.7% technical success). The procedures lasted 147+/-71 min. Length of stay in the observation unit was 20.6+/-13.5 h. Blood transfusion was required in 10%. Sixty two percent of the patients were discharged before 72 h. One patient died 8 days after surgery due to a myocardial infarction (1.3%). During follow-up (3-90 months), 1 patient developed late AAA enlargement due to a type I endoleak, requiring a new endograft. No AAA rupture was observed. Survival at 4 years was 84.2% (SE =9.2). Endovascular re-intervention free survival was 82.7% (SE =9.5). CONCLUSION: Endovascular surgery allows effective exclusion of AAA avoiding progressive enlargement and/or rupture and is a good alternative to open repair. Close and frequent postoperative follow up is mandatory.

Renal function and cardiopulmonary bypass in pediatric cardiac surgical patients.

We studied prospectively the perioperative changes of renal function in nine children undergoing cardiac surgery with cardiopulmonary bypass (CPB). Glomerular filtration rate (GFR) and effective renal plasma flow (ERPF) were measured with inulin and (131)I-hippuran clearances before CPB, during hypo and normothermic CPB, following sternal closure and 1 h postoperatively. Urinary alpha glutathione S-transferase (alpha GS-T) was measured pre- and postoperatively as a marker for tubular cellular damage. Plasma and urine creatinine and electrolytes were measured. Free water, osmolal and creatinine clearances, as well as fractional excretion of sodium (FeNa) and potassium transtubular gradient (TTKG) were calculated. GFR was normal before and after surgery. ERPF was low before and after surgery; it increased significantly immediately after CPB. Filtration fraction (FF) was abnormally elevated before and after surgery; however, a significant decrease during normothermic CPB and sternal closure was found. Alpha GS-T presented a moderate, but nonsignificant increase postoperatively. FeNa also increased in this period, but not significantly. Creatinine, osmolal, free water clearances, as well as TTKG, were normal in all patients pre- and postoperatively. We conclude that there is no evidence of clinically significant deterioration of renal function in children undergoing repair of cardiac lesions under CPB. Minor increases of alpha GS-T in urine postoperatively did not confirm cellular tubular damage. There was no tubular dysfunction at that time.

Práctica transfusional en pacientes adultos sometidos a cirugía cardíaca con circulación extracorpórea: experiencia de la Pontificia Universidad Católica de Chile / Prediction of blood transfusion need in patients undergoing open heart surgery: the experience of Catholic University Hospital, Chile

Antecedentes: La cirugía cardíaca se asocia a un alto consumo de sangre homóloga. Si conocemos los factores quepredicen una mayor necesidad de transfusión, podremos implementar mejores estrategias de ahorro sanguíneo. Objetivo: Describir la práctica transfusional en pacientes adultos sometidos a cirugía con circulación extracorpórea (CEC) en la Pontificia Universidad Católica de Chile. Materiales y métodos: Se recolectaron en forma retrospectiva los datos de 194 pacientes adultos sometidos a cirugía cardíaca con CEC, entre octubre de 2003 y marzo de 2004. Se realizó una descripción de la práctica transfusional y un análisis de riesgo uni y multivariado. Resultados: El 61,8 por ciento de los pacientes se transfundieron durante la hospitalización. La transfusión intraoperatoria se relacionó con sangrado y la transfusión postoperatoria con la corrección de un hematocrito bajo. Los factores predictores de transfusión fueron cirugía de urgencia, tiempo prolongado de CEC, edad avanzada y un menor hematocrito al momento de ingresar a la unidad de cuidado postoperatorio. El hematocrito bajo al inicio de la cirugía, una menor temperatura durante CEC y un mayor sangrado en el postoperatorio predijeron el uso de más de dos unidades de glóbulos rojos (GR).Los pacientes que recibieron más de 2 unidades de GR presentaron en forma significativa mayor incidencia de neumonía, insuficiencia respiratoria y sepsis. Conclusiones: La transfusión sanguínea en cirugía cardíaca se relaciona directamente con la complejidad de los pacientes y los procedimientos. Las técnicas de ahorro de sangre deben dirigirse hacia la disminución del sangrado, la hemodilución y a estrictos criterios de transfusión intra y postoperatorios.

Background: Cardiac surgery is associated with frequent use of homologous blood. The knowledge of factors that influence the need for transfusion might help us implement strategies to avoid unnecessary blood administration. Objective: To describe the current transfusion practices in adults undergoing open cardiac surgery with extra corporeal circulation (ECC) at the Pontificia Universidad Católica of Chile Hospital. To identify factors that predict the use of transfusion. Methods: Data from 194 adult patients submitted to cardiac surgery with ECC between October 2003 and March 2004 were obtained retrospectively. Transfusional practices were identified. Uni and multivariate risk analysis was used to predict the need for transfusion.Results: 61,8 percent of patients were transfused during their hospital stay. Intraoperative transfusion was related to bleeding while post operative transfusion was performed to correct a low hematocrit value. Factors predicting transfusion were: emergency surgery, prolonged EEC time, older age and lower hematocrit value when entering the ICU. Preoperative hematocrit, lower temperature during ECC and post operative bleeding predicted the use of more than 2 red blood cell (RBC) packs. Patients receiving more than 2 RBC packs had a significantly higher incidence of pneumonia, sepsis and respiratory failure. Conclusion: Blood transfusion during cardiac surgery is directly related to complexity of procedures and severeness of patient illness. Blood saving techniques must be directed to reducing the amount of bleeding, allowing hemodilution and defining strict criteria for intra and post operative transfusions.

[Extracorporeal membrane oxygenation (ECMO): consolidation of a neonatal-pediatric program in Chile and report of three cases]. / Oxigenación con membrana extracorpórea en pacientes pediátricos: comunicación de los 3 primeros casos tratados.

Extracorporeal membrane oxygenation (ECMO) improves survival in neonatal and pediatric patients with reversible severe respiratory or cardiac failure, in whom intensive treatment fails. Since 1999, a multidisciplinary team is trained to form the first neonatal-pediatric ECMO center in Chile, according to the norms of the Extracorporeal Life Support Organization (ELSO). During 2003 the first three patients were admitted to the program: a male newborn with pulmonary hypertension, a 38 days old female operated for a total anomalous pulmonary venous connection and a 3 months old male with a severe pneumonia caused by respiratory syncytial virus. They remained in ECMO for five, seven and nine days respectively and all survived to the procedure. No neurological complications were observed after one and a half year of follow up. This consolidates the first national neonatal-pediatric ECMO program, associated to ELSO. Up to date, twelve patients have been admitted to the program.