Impacto en el manejo diagnóstico/terapéutico de la ecocardiografía básica dirigida a objetivos concretos en una UCI de cirugía cardíaca / Impact of goal directed basic echocardiography on diagnostic and therapeutic management in an ICU of cardiac surgery

OBJETIVO: Pocos estudios han evaluado el impacto en el diagnóstico y tratamiento de la ecocardiografía transtorácica básica en los pacientes postoperados de cirugía cardíaca. El objetivo de nuestro estudio fue valorar el impacto de la ecocardiografía transtorácica básica en el manejo diagnóstico y terapéutico de estos pacientes. DISEÑO: Durante 18 meses se estudiaron prospectivamente todos los pacientes postoperados de cirugía cardíaca que ingresaron en el Servicio de Medicina Intensiva de un hospital universitario. Se realizó una valoración clínica a todos ellos para establecer un diagnóstico y un tratamiento inicial. Se realizó una ecocardiografía transtorácica básica para valoración diagnóstica, que se comparó con la valoración clínica. En caso de discrepancia, se valoró cambiar el tratamiento en función a la ecocardiografía y se evaluó la respuesta terapéutica. Se realizó un análisis descriptivo de los hallazgos. RESULTADOS: Se incluyeron 136 pacientes y se realizaron 203 ecocardiografías. La ecocardiografía transtorácica difería del diagnóstico inicial en 101 (49,8%) ecocardiografías. En 56 de estas (55,44%) se obtuvo un diagnóstico alternativo, lo que comportó un cambio en el tratamiento en 30pacientes (53,6%). Encontramos mejoría clínica significativa en 26 de estos pacientes (86,76%) en los siguientes 30-60min. CONCLUSIONES: La ecocardiografía transtorácica básica es útil en el manejo diagnóstico y terapéutico de los pacientes postoperados de cirugía cardíaca. En la mitad de las ecocardiografías realizadas no se pudo confirmar el diagnóstico clínico. En la mayoría de los pacientes en que observamos cambio en el diagnóstico debido a la ecocardiografía, se observó mejoría clínica tras el cambio de tratamiento

OBJECTIVE: Few studies have evaluated the impact in diagnosis and therapeutic management of basic transthoracic echocardiography in postoperated cardiac surgery. The aim of our study was to evaluate the impact of basic transthoracic echocardiography in the management of this kind of patients. DESIGN: Over an 18-month period, we prospectively studied all patients admitted to a university hospital Intensive Care Unit following heart surgery. We evaluated clinically all of them to establish a diagnosis and an initial treatment. We performed basic transthoracic echocardiography for a diagnosis evaluation that was compared with clinical diagnosis. If they differed, we assessed to change treatment and evaluate the therapeutic response. We performed a descriptive analysis. RESULTS: We included 136 patients and performed 203 echocardiographies. Transthoracic echocardiography differed of initial diagnosis in 101 (49.8%) echocardiographies. In 56 of these echocardiographies (55.44%), we could give an alternative diagnosis with a change in the treatment in 30patients (53,6%). We found clinical improvement in 26 patients (86.76%) in the following 30-60minutes. CONCLUSIONS: Basic transthoracic echocardiography is useful in diagnostic and therapeutic management of postoperative cardiac surgery patients. We could not confirm the clinical diagnosis in half of the performed echocardiographies. In most patients in whom we observe a change in the diagnosis due to echocardiography, we observed a clinical improvement after changing the treatment

Impact of goal directed basic echocardiography on diagnostic and therapeutic management in an ICU of cardiac surgery. / Impacto en el manejo diagnóstico/terapéutico de la ecocardiografía básica dirigida a objetivos concretos en una UCI de cirugía cardíaca.

OBJECTIVE: Few studies have evaluated the impact in diagnosis and therapeutic management of basic transthoracic echocardiography in postoperated cardiac surgery. The aim of our study was to evaluate the impact of basic transthoracic echocardiography in the management of this kind of patients. DESIGN: Over an 18-month period, we prospectively studied all patients admitted to a university hospital Intensive Care Unit following heart surgery. We evaluated clinically all of them to establish a diagnosis and an initial treatment. We performed basic transthoracic echocardiography for a diagnosis evaluation that was compared with clinical diagnosis. If they differed, we assessed to change treatment and evaluate the therapeutic response. We performed a descriptive analysis. RESULTS: We included 136 patients and performed 203 echocardiographies. Transthoracic echocardiography differed of initial diagnosis in 101 (49.8%) echocardiographies. In 56 of these echocardiographies (55.44%), we could give an alternative diagnosis with a change in the treatment in 30patients (53,6%). We found clinical improvement in 26 patients (86.76%) in the following 30-60minutes. CONCLUSIONS: Basic transthoracic echocardiography is useful in diagnostic and therapeutic management of postoperative cardiac surgery patients. We could not confirm the clinical diagnosis in half of the performed echocardiographies. In most patients in whom we observe a change in the diagnosis due to echocardiography, we observed a clinical improvement after changing the treatment.

Evaluation of intensivist basic training in transthoracic echocardiography in the postoperative period of heart surgery / Evaluación de la formación de intensivistas en ecocardiografía transtorácica básica en el postoperatorio de cirugía cardíaca

Background: Transthoracic echocardiography can significantly change the management of many critical patients, and is being incorporated into many Intensive Care Units (ICU). Very few studies have examined the feasibility and impact of intensivists performing basic transthoracic echocardiography upon the management of critical patients after cardiac surgery. The present study therefore evaluates the quality of acquisition and accuracy of intensivist interpretation of basic transthoracic echocardiograms in the postoperative period of heart surgery. Methods: Over an 8-month period we prospectively studied 148 patients within 24h after admission to a university hospital ICU following heart surgery. We performed basic transthoracic echocardiography to evaluate ventricular function, pericardial effusion, hypovolemia and mitral regurgitation. Cohen's Kappa was used to compare transthoracic echocardiograms obtained by intensivists with basic versus advanced training. Concordance on image acquisition and interpretation was evaluated. Results: We analyzed data of adequate transthoracic echocardiograms in 148 patients (92.5%). Apical four-chamber view and advanced trainees obtained better quality images. Concordance was good for right and left ventricular function (kappa=0.7±0.14 and 0.87±0.05, respectively), and moderate for the remaining parameters. Interpretation concordance between basic and advanced training intensivists was good (kappa=0.73±0.05). Conclusions: Intensivists with basic training in echocardiography are capable of performing and interpreting echocardiograms in most patients during the postoperative period of heart surgery

Objetivo: La ecocardiografía transtorácica puede cambiar significativamente el manejo en muchos pacientes críticos y se está incorporando dentro de muchas unidades de cuidados intensivos (UCI). Pocos estudios han examinado la factibilidad y el impacto de la ecocardiografía transtorácica básica realizada por intensivistas en el manejo de los pacientes críticos después de una cirugía cardíaca. Por ello, nosotros evaluamos la calidad de adquisición y la precisión en la interpretación de la ecocardiografía básica realizada por intensivistas en los pacientes postoperados de cirugía cardíaca. Métodos: Durante 8 meses, estudiamos prospectivamente 148 pacientes postoperados de cirugía cardíaca dentro de las primeras 24h de ingreso en una UCI de un hospital universitario. Realizamos una ecocardiografía transtorácica básica para evaluar función ventricular, líquido pericárdico, hipovolemia y regurgitación mitral. Utilizamos el coeficiente kappa de Cohen para comparar las ecocardiografías transtorácicas realizadas por los intensivistas con formación básica versus avanzada. Evaluamos la concordancia en la adquisición de imágenes y su interpretación. Resultados: Analizamos los datos de las ecocardiografías transtorácicas de 148 pacientes (92,5%). La visión apical cuatro-cámaras y los intensivistas con formación avanzada obtuvieron mayor calidad de imagen. La concordancia fue buena para la función ventricular derecha e izquierda (kappa=0,7±0,14 y 0,87±0,05, respectivamente), y moderada para el resto de parámetros. La concordancia de la interpretación entre los intensivistas con formación básica y avanzada fue buena (kappa=0,73±0,05). Conclusiones: Los intensivistas formados en ecocardiografía transtorácica básica son capaces de obtener e interpretar las ecocardiografías en la mayoría de postoperados programados de cirugía cardíaca

Evaluation of intensivist basic training in transthoracic echocardiography in the postoperative period of heart surgery.

BACKGROUND: Transthoracic echocardiography can significantly change the management of many critical patients, and is being incorporated into many Intensive Care Units (ICU). Very few studies have examined the feasibility and impact of intensivists performing basic transthoracic echocardiography upon the management of critical patients after cardiac surgery. The present study therefore evaluates the quality of acquisition and accuracy of intensivist interpretation of basic transthoracic echocardiograms in the postoperative period of heart surgery. METHODS: Over an 8-month period we prospectively studied 148 patients within 24h after admission to a university hospital ICU following heart surgery. We performed basic transthoracic echocardiography to evaluate ventricular function, pericardial effusion, hypovolemia and mitral regurgitation. Cohen's Kappa was used to compare transthoracic echocardiograms obtained by intensivists with basic versus advanced training. Concordance on image acquisition and interpretation was evaluated. RESULTS: We analyzed data of adequate transthoracic echocardiograms in 148 patients (92.5%). Apical four-chamber view and advanced trainees obtained better quality images. Concordance was good for right and left ventricular function (kappa=0.7±0.14 and 0.87±0.05, respectively), and moderate for the remaining parameters. Interpretation concordance between basic and advanced training intensivists was good (kappa=0.73±0.05). CONCLUSIONS: Intensivists with basic training in echocardiography are capable of performing and interpreting echocardiograms in most patients during the postoperative period of heart surgery.

Saturación tisular de oxígeno en el paciente crítico / Tissue oxygen saturation in the critically ill patient

Los objetivos de la reanimación hemodinámica van dirigidos a la restauración de variables macrocirculatorias de presión y flujo de marcado carácter global. Sin embargo, a día de hoy, múltiples trabajos han evidenciado que, a pesar de la normalización de estas variables, pueden persistir alteraciones de la perfusión tanto a nivel regional como microcirculatorio, y que dichas alteraciones se han correlacionado de forma independiente con un pronóstico desfavorable del paciente. Esta evidencia ha propiciado un creciente interés por nuevas tecnologías dirigidas a la evaluación de la circulación regional y la microcirculación. La espectroscopia de luz cercana al infrarrojo nos permite monitorizar la saturación tisular de oxígeno, y ha sido propuesta como medida rápida, no invasiva y continua de la circulación regional. La presente revisión trata de exponer la evidencia actual sobre la espectroscopia de luz cercana al infrarrojo y su potencial uso clínico en la reanimación de los pacientes críticos en shock

Hemodynamic resuscitation seeks to correct global macrocirculatory parameters of pressure and flow. However, current evidence has shown that despite the normalization of these global parameters, microcirculatory and regional perfusion alterations can persist, and these alterations have been independently associated with a poorer patient prognosis. This in turn has lead to growing interest in new technologies for exploring regional circulation and microcirculation. Near infra-red spectroscopy allows us to monitor tissue oxygen saturation, and has been proposed as a noninvasive, continuous and easy-to-obtain measure of regional circulation. The present review aims to summarize the existing evidence on near infra-redspectroscopy and its potential clinical role in the resuscitation of critically ill patients in shock

[Tissue oxygen saturation in the critically ill patient]. / Saturación tisular de oxígeno en el paciente crítico.

Hemodynamic resuscitation seeks to correct global macrocirculatory parameters of pressure and flow. However, current evidence has shown that despite the normalization of these global parameters, microcirculatory and regional perfusion alterations can persist, and these alterations have been independently associated with a poorer patient prognosis. This in turn has lead to growing interest in new technologies for exploring regional circulation and microcirculation. Near infra-red spectroscopy allows us to monitor tissue oxygen saturation, and has been proposed as a noninvasive, continuous and easy-to-obtain measure of regional circulation. The present review aims to summarize the existing evidence on near infra-red spectroscopy and its potential clinical role in the resuscitation of critically ill patients in shock.

[Hemodynamic monitoring in the critically patient. Recomendations of the Cardiological Intensive Care and CPR Working Group of the Spanish Society of Intensive Care and Coronary Units]. / Monitorización hemodinámica en el paciente crítico. Recomendaciones del Grupo de Trabajo de Cuidados Intensivos Cardiológicos y RCP de la Sociedad Española de Medicina Intensiva, Crítica y Unidades Coronarias.

Hemodynamic monitoring offers valuable information on cardiovascular performance in the critically ill, and has become a fundamental tool in the diagnostic approach and in the therapy guidance of those patients presenting with tissue hypoperfusion. From introduction of the pulmonary artery catheter to the latest less invasive technologies, hemodynamic monitoring has been surrounded by many questions regarding its usefulness and its ultimate impact on patient prognosis. The Cardiological Intensive Care and CPR Working Group (GTCIC-RCP) of the Spanish Society of Intensive Care and Coronary Units (SEMICYUC) has recently impulsed the development of an updating series in hemodynamic monitoring. Now, a final series of recommendations are presented in order to analyze essential issues in hemodynamics, with the purpose of becoming a useful tool for residents and critical care practitioners involved in the daily management of critically ill patients.

Prognostic implications of tissue oxygen saturation in human septic shock.

PURPOSE: To analyze the prognostic value of tissue oxygen saturation (StO(2)) in septic shock patients with restored mean arterial pressure (MAP). METHODS: This was a prospective observational study of patients admitted to the ICU in the early phase of septic shock, after restoration of MAP. Demographic data, severity score, hemodynamics, blood lactate, acid-base status, and StO(2) were measured at inclusion followed by a transient vascular occlusion test (VOT) to obtain the StO(2)-deoxygenation (DeOx) and StO(2)-reoxygenation (ReOx) rates. Sequential organ failure assessment (SOFA) score was measured at inclusion and after 24 h. RESULTS: Thirty-three patients were studied. StO(2) was 76 ± 10%, DeOx -12.2 ± 4.2%/min, and ReOx 3.02 ± 1.70%/s. MAP showed a significant correlation with VOT-derived slopes (r = -0.4, p = 0.04 for DeOx; and r = 0.55, p < 0.01 for ReOx). After 24 h, 17 patients (52%) had improved SOFA scores. Patients who did not improve their SOFA showed less negative DeOx values at inclusion. The association between DeOx and SOFA evolution was not affected by MAP. Both DeOx and ReOx impairment correlated with longer ICU stay (r = 0.44, p = 0.05; and r = -0.43, p = 0.05, respectively). CONCLUSIONS: In a population of septic shock patients with restored MAP, impaired DeOx was associated with no improvement in organ failures after 24 h. Decrements in DeOx and ReOx were associated with longer ICU stay. DeOx and ReOx were linked to MAP, and thus, their interpretation needs to be made relative to MAP.

Objetivos de la reanimación hemodinámica / Objectives of hemodynamic resuscitation

La insuficiencia cardiovascular o shock, de cualquier etiología, se caracteriza por la inadecuada perfusión de los tejidos del organismo, produciendo una situación de desequilibrio entre el aporte y la demanda de oxígeno. La disminución de la disponibilidad de oxígeno en el área celular se traduce en un aumento del metabolismo anaerobio, con producción de lactato e hidrogeniones, derivando en la acidosis láctica. El grado de hiperlactatemia y acidosis metabólica va a correlacionarse directamente con el desarrollo de fracaso orgánico y mal pronóstico del individuo.La llegada de oxígeno a los tejidos depende fundamentalmente de una presión de perfusión del tejido suficiente y de un transporte de oxígeno adecuado. La adecuación de estos dos parámetros fisiológicos va a posibilitar la restauración del equilibrio entre aporte y demanda celular de oxígeno, revirtiendo el proceso de anaerobiosis. La monitorización de variables como el lactato y las saturaciones venosas de oxígeno (central o mixta) durante la fase aguda del shock serán útiles en la determinación de persistencia o resolución de la hipoxia tisular. En los últimos años, han aparecido nuevas tecnologías capaces de evaluar la perfusión local y la microcirculación, como la tonometría gástrica, la espectroscopia en el límite de la luz infrarroja y la videomicroscopia. Aunque la monitorización de parámetros de carácter regional ha demostrado su valor pronóstico, no se dispone de evidencia suficiente que le otorgue utilidad en la guía del proceso de reanimación. En conclusión, a la espera de disponer de parámetros capaces de proporcionarnos información útil de perfusión local, la reanimación hemodinámica sigue basada en la (..)(AU)

Cardiovascular failure or shock, of any etiology, is characterized by ineffective perfusion of body tissues, inducing derangements in the balance between oxygen delivery and consumption. Impairment in oxygen availability on the cellular level causes a shift to anaerobic metabolism, with an increase in lactate and hydrogen ion production that leads to lactic acidosis. The degree of hyperlactatemia and metabolic acidosis will be directly correlated tothe development of organ failure and poor outcome of the individuals. The amount of oxygen available at the tissues will depend fundamentally on an adequate level of perfusion pressure and oxygen delivery. The optimization of these two physiologic parameters can re-establish the balance between oxygen delivery and consumption on the cellular level, thus, restoring the metabolism to its aerobic paths. Monitoring variables such as lactate and oxygen venous saturations (either central or mixed) during the initial resuscitation of shock will be helpful to determine whether tissue hypoxia is still present or not. Recently, some new technologies have been developed in order to evaluate local perfusion and microcirculation, such as gastric tonometry, near-infrared spectroscopy and video microscopy. Although monitoring these regional parameters has demonstrated its prognostic value, there is a lack of evidence regarding to its usefulness during the resuscitation process. In conclusion, hemodynamic resuscitation is still based on the rapid achievement of adequate levels of perfusion pressure, and then on the modification of oxygen delivery variables, in order to restore physiologic values of ScvO2/SvO2 and resolve lactic acidosis and/or hyperlactatemia (AU)

[Objectives of hemodynamic resuscitation]. / Objetivos de la reanimación hemodinámica.

Cardiovascular failure or shock, of any etiology, is characterized by ineffective perfusion of body tissues, inducing derangements in the balance between oxygen delivery and consumption. Impairment in oxygen availability on the cellular level causes a shift to anaerobic metabolism, with an increase in lactate and hydrogen ion production that leads to lactic acidosis. The degree of hyperlactatemia and metabolic acidosis will be directly correlated to the development of organ failure and poor outcome of the individuals. The amount of oxygen available at the tissues will depend fundamentally on an adequate level of perfusion pressure and oxygen delivery. The optimization of these two physiologic parameters can re-establish the balance between oxygen delivery and consumption on the cellular level, thus, restoring the metabolism to its aerobic paths. Monitoring variables such as lactate and oxygen venous saturations (either central or mixed) during the initial resuscitation of shock will be helpful to determine whether tissue hypoxia is still present or not. Recently, some new technologies have been developed in order to evaluate local perfusion and microcirculation, such as gastric tonometry, near-infrared spectroscopy and videomicroscopy. Although monitoring these regional parameters has demonstrated its prognostic value, there is a lack of evidence regarding to its usefulness during the resuscitation process. In conclusion, hemodynamic resuscitation is still based on the rapid achievement of adequate levels of perfusion pressure, and then on the modification of oxygen delivery variables, in order to restore physiologic values of ScvO(2)/SvO(2) and resolve lactic acidosis and/or hyperlactatemia.

[Limitation of therapeutic effort: a "question for professionals or for patients as well?"]. / Limitación del esfuerzo terapéutico: "cuestión de profesionales o también de enfermos?"

Limitation of therapeutic effort (LTE) is a medical term that is not free of polemic. Thus, some hold that limitation is an expression that could be considered pejorative and believe it would be more appropriate to speak of "adjustment", in order to avoid "negative" considerations concerning patient care. Because it is not a case of "ceasing to act" but of adopting a proactive attitude that includes adding or modifying measures according to the therapeutic aims of the moment. There are numerous definitions of LTE. They usually coincide in referring to not starting or withdrawing a certain treatment in which no benefits to the patient are generated, in situations where the latter is able or unable to decide for himself. Its justification is found facing a perception of disproportion between therapeutic ends and means. Nowadays, LET is fully accredited. Its use is very frequent in the field of critical care, with positions adopted by different scientific societies that endorse it to the point of considering it a standard of quality. LTE has been dealt with from numerous perspectives in many articles and forums of debate, so it would initially seems difficult to contribute something novel concerning the issue. However, there is one question that does not seem to have been sufficiently explored: Does the decision on LTE have a purely technical character, that is to say, is it the responsibility of the professional, or should the patient also intervene, or if he/she is unable to, his/her representative?

Limitación del esfuerzo terapéutico: “cuestión de profesionales o ¿también de enfermos?” / Limitation of therapeutic effort: a “question for professionals or for patients as well?”

Limitación del esfuerzo terapéutico (LET) es untérmino médico no exento de polémica. Así, algunosestiman que limitación es una expresión que podríaconsiderarse peyorativa y creen que sería más adecuadohablar de “ajuste” para evitar consideraciones“negativas” sobre la atención al paciente. Porque nose trata solo de “dejar de hacer” sino de adoptar unaactitud proactiva que incluye añadir o modificarmedidas de acuerdo a los objetivos terapéuticos delmomento.Existen múltiples definiciones de LET. Suelen coincidiren referirse a no iniciar o retirar un determinadotratamiento, en el que no se generan beneficios alpaciente, tanto en situaciones en las que éste puede ono puede decidir por sí mismo. Su justificación se daante la percepción de desproporción entre los fines ymedios terapéuticos. Hoy en día la LET está plenamenteacreditada siendo muy frecuente en el ámbito de cuidadoscríticos, con posicionamientos de diferentessociedades científicas que la avalan hasta considerarlaun estándar de calidad.La LET ha sido tratada en muchos artículos y forosde debate desde múltiples perspectivas, por lo que deentrada puede parecer difícil aportar algo novedososobre la cuestión. Sin embargo, hay una cuestión queparece insuficientemente explorada: ¿La decisión deLET es sólo de carácter técnico, es decir, compete únicamenteal profesional o deben intervenir también elpaciente, o en su defecto, su representante?

Limitation of therapeutic effort (LTE) is a medicalterm that is not free of polemic. Thus, some hold thatlimitation is an expression that could be consideredpejorative and believe it would be more appropriate tospeak of “adjustment”, in order to avoid “negative”considerations concerning patient care. Because it isnot a case of “ceasing to act” but of adopting a proactiveattitude that includes adding or modifying measuresaccording to the therapeutic aims of the moment.There are numerous definitions of LTE. Theyusually coincide in referring to not starting orwithdrawing a certain treatment in which no benefitsto the patient are generated, in situations where thelatter is able or unable to decide for himself. Itsjustification is found facing a perception ofdisproportion between therapeutic ends and means.Nowadays, LET is fully accredited. Its use is veryfrequent in the field of critical care, with positionsadopted by different scientific societies that endorse itto the point of considering it a standard of quality.LTE has been dealt with from numerousperspectives in many articles and forums of debate, soit would initially seems difficult to contribute somethingnovel concerning the issue. However, there is onequestion that does not seem to have been sufficientlyexplored: Does the decision on LTE have a purelytechnical character, that is to say, is it the responsibilityof the professional, or should the patient also intervene,or if he/she is unable to, his/her representative?

Volume expansion using pentastarch does not change gastric-arterial CO2 gradient or gastric intramucosal pH in patients who have sepsis syndrome.

OBJECTIVE: In hypovolemic patients with sepsis syndrome, to determine the effects of colloid volume infusion using 10% pentastarch on abnormal gastric tonometer measurements (gastric intramucosal CO2 tension, gastric intramucosal-arterial PCO2 gradient, and gastric intramucosal pH [pHi]) and on cardiac index, global oxygen delivery, and hemoglobin. DESIGN: Prospective prepost intervention study. SETTING: Tertiary care, university-affiliated 15-bed general systems intensive care unit. PATIENTS: Patients were studied who had sepsis syndrome, who had pulmonary arterial catheters in place, who were hypovolemic (pulmonary arterial occlusion pressure [PAOP] <15 mm Hg), and who had a gastric arterial PCO2 gradient >10 mm Hg. INTERVENTIONS: Baseline measurements of gastric intramucosal CO2 tension, gastric intramucosal-arterial PCO2 gradient, and pHi, as well as arterial lactate, pulmonary arterial occlusion, central venous and systemic arterial pressures, thermodilution cardiac output, and temperature. Boluses of 500 mL pentastarch were administered to a total of 1,000 mL or until PAOP was >18 mm Hg. Measurements were repeated at 30 mins and 120 mins postinfusion of pentastarch. MAIN RESULTS: Volume infusion using pentastarch did not change gastric PCO2, gastric-arterial PCO2 gradient, or pHi. Volume expansion with pentastarch significantly increased cardiac index, global oxygen delivery, and PAOP. Administration of pentastarch decreased hemoglobin and arterial lactate at 30 mins but not at 120 mins. CONCLUSIONS: Volume expansion using a colloidal solution of 10% pentastarch does not change abnormal intramucosal CO2 tension, gastric-arterial PCO2 gradient, or pHi in critically ill hypovolemic patients who have sepsis syndrome despite increasing cardiac index, oxygen delivery, and pulmonary artery occlusion pressure.

Effect of acute moderate changes in PaCO2 on global hemodynamics and gastric perfusion.

OBJECTIVE: To describe global hemodynamics and splanchnic perfusion changes in response to acute modifications in Paco2 in hemodynamically stable patients. DESIGN: Prospective, randomized crossover study. SETTING: Medical-surgical intensive care unit at a community hospital (400,000 inhabitants). PATIENTS: Ten critically ill patients who were sedated, paralyzed, and mechanically ventilated. INTERVENTIONS: Hypercapnia and hypocapnia were obtained by increasing and reducing instrumental deadspace in random order. After each intervention, patients returned to the basal condition. Each period lasted 80 min: 20 min to achieve stable Paco2 and 60 min for tonometer equilibration. In each period, global hemodynamic variables and tonometric data were collected. The periods were compared using analysis of variance. MEASUREMENTS AND MAIN RESULTS: Acute hypercapnia (Paco2 from 40+/-3 to 52+/-3 torr, p<.05) increased cardiac index (3.43+/-0.37 vs. 3.97+/-0.43 mL/min/m2, p<.05), heart rate (95+/-6 vs. 105+/-3 beats/min, p<.05), and mean pulmonary artery pressure (21+/-1 vs. 24+/-1 mm Hg, p<.05) and reduced systemic vascular resistance (992+/-98 vs. 813+/-93 dyne x sec/ cm5, p<.05) and oxygen extraction ratio (27+/-3% vs. 22+/-2%, p<.05). Standardized intramucosal Pco2 increased from 49+/-2 to 61+/-3 torr (p<.05) with an associated decrease in calculated intramucosal pH ([pHi] 7.35+/-0.03 vs. 7.25+/-0.02, p<.05), but the gastro-arterial Pco2 gradient (deltaPco2) did not change. Acute hypocapnia (Paco2 from 41+/-3 to 34+/-3 torr, p<.05; pH 7.41+/-0.01 to 7.47+/-0.02, p<.05) induced slight increments in systemic vascular resistance (995+/-117 vs. 1088 +/- 160 dyne x sec/cm5, p<.05) and oxygen extraction ratio (28+/-2% vs. 30+/-2%, p<.05). Standardized intramucosal Pco2 decreased (50+/-4 vs. 44+/-3 torr, p<.05), pHi increased (7.33+/-0.03 vs. 7.36+/-0.02; p<.05), but deltaPco2 did not change. CONCLUSIONS: In this small group of stable patients, moderate acute variations in Paco2 had a significant effect on global hemodynamics, but splanchnic perfusion, assessed by deltaPco2, did not change. In these conditions, the use of pHi to evaluate gastric perfusion appears unreliable.

Acute small bowel pseudo-obstruction due to AL amyloidosis: a case report and literature review.

Amyloidosis may uncommonly present with intestinal pseudo-obstruction. Previous reports have described an acute presentation with AA amyloid and a more chronic syndrome with AL amyloid. We report the case of a 78-yr-old man who presented with clinical and radiographic features of an acute small bowel obstruction and who, at laparotomy, was found to have intestinal pseudo-obstruction due to AL amyloidosis. We believe this case represents the first report of acute pseudo-obstruction from AL amyloidosis; awareness of this presentation may facilitate earlier diagnosis.

Inhaled nitric oxide does not improve cardiac or pulmonary function in patients with an exacerbation of chronic obstructive pulmonary disease.

OBJECTIVE: To determine whether inhaled nitric oxide (NO) improves right ventricular function in mechanically ventilated patients with severe chronic obstructive pulmonary disease (COPD). DESIGN: Open, prospective, controlled trial. SETTING: General intensive care unit of a community hospital. PATIENTS: Twelve patients with acute respiratory failure caused by acute exacerbation of COPD requiring mechanical ventilation. INTERVENTIONS: Insertion of a pulmonary artery catheter modified with a rapid response thermistor and a radial arterial catheter. Nitric oxide was then administered to the patient via a T piece placed between the Y piece of the ventilator and the endotracheal tube. MEASUREMENTS AND MAIN RESULTS: Hemodynamic and gasometric variables were recorded before NO inhalation, during administration of inhaled NO (20 ppm, 20 mins), and 20 mins after NO discontinuation. Inhaled NO reduced pulmonary artery pressure from 26 +/- 6 to 22 +/- 5 mm Hg (p = .0004), but arterial oxygenation, cardiac output, and right ventricular ejection fraction remained unmodified (41% +/- 9% vs. 41% +/- 8%; not significant). Calculated pulmonary vascular resistance decreased from 453 +/- 233 to 348 +/- 108 dyne x sec/cm5 x m2 (p = .02), and right ventricular volumes did not change. Subsequently, right ventricular end-systolic pressure/volume ratio decreased from 0.52 +/- 0.22 to 0.44 +/- 0.19 mm Hg/mL/m2 (p = .01). No significant correlation was observed between the changes of pulmonary artery pressure (or pulmonary vascular resistance) and changes of right ventricular ejection fraction. CONCLUSION: Inhalation of NO does not seem to improve either right ventricular function or arterial oxygenation in patients with acute respiratory failure caused by acute exacerbation of COPD.

Effect of ranitidine on gastric intramucosal pH in critically ill patients.

OBJECTIVE: To determine whether ranitidine a) increases the values of gastric intramucosal pH (pHi) in critically ill patients, as determined by tonometry; b) reduces the variability of these measurements. DESIGN: Prospective, double blind, randomized, placebo-controlled study. SETTING: General Intensive Care Unit of a teaching hospital. PATIENTS: Twenty-five critically ill, mechanically ventilated patients requiring arterial catheter and nasogastric tube. INTERVENTIONS: Tonometer placement; blind, random administration of intravenous ranitidine (50 mg) or placebo. MEASUREMENTS AND MAIN RESULTS: Tonometer saline PCO2 (PCO2i), arterial blood gases, gastric juice pH and pHi were determined immediately before, and 2, 4, 6 and 8 h after, ranitidine (12 patients) or placebo (13 patients). Ranitidine significantly increased gastric juice pH, but did not affect PCO2i or pHi; pHi was 7.34 +/- 0.14 before ranitidine, and 7.30 +/- 0.12, 7.31 +/- 0.11, 7.31 +/- 0.14 and 7.31 +/- 0.12-2, 4, 6 and 8 h, respectively, after ranitidine administration (p = 0.55). Ranitidine did not modify the coefficients of variation of PCO2i or pHi, either. No significant changes in gastric juice pH, PCO2i or pHi were observed in the placebo group. CONCLUSIONS: In critically ill patients, ranitidine has no effect on pHi values, and does not increase the reproducibility of pHi measurements.

Effect of sucralfate on gastric intramucosal pH in critically ill patients.

OBJECTIVE: To determine whether sucralfate administration affects the tonometric measurement of gastric intramucosal pH (pHi). DESIGN: Non-randomized observational study. SETTING: General intensive care unit of a teaching hospital. PATIENTS: Twenty critically ill, mechanically ventilated, consecutively admitted patients requiring an arterial catheter and nasogastric tube. INTERVENTIONS: Tonometer placement and sucralfate administration. MEASUREMENTS AND MAIN RESULTS: We simultaneously determined tonometer saline PCO2 (PCO2i), arterial blood gases, pH of gastric juice and pHi. These parameters were evaluated immediately before sucralfate administration, and 2 h and 4 h after. We did not detect any change in either PCO2i or pHi after sucralfate administration (PCO2i: basal 6.4 +/- 1.7, 2 h 6.3 +/- 1.7, 4 h 6.3 +/- 1.7; pHi: basal 7.35 +/- 0.13, 2 h 7.36 +/- 0.12, 4 h 7.36 +/- 0.12). CONCLUSIONS: Sucralfate does not affect the tonometric measurement of PCO2i and pHi.

Hemodynamic and gas exchange responses to inhalation of nitric oxide in patients with the acute respiratory distress syndrome and in hypoxemic patients with chronic obstructive pulmonary disease.

OBJECTIVE: Inhalation of nitric oxide (NO) can improve oxygenation and decrease mean pulmonary artery pressure (MPAP) in patients with the acute respiratory distress syndrome (ARDS). It is not known whether inhaled NO exerts a similar effect in hypoxemic patients with chronic obstructive pulmonary disease (COPD). DESIGN: Prospective clinical study. SETTING: General intensive care unit in Sabadell, Spain. PATIENTS: Nine mechanically ventilated COPD patients (mean age 72 +/- 2 years; forced expiratory volume in 1 s 0.91 +/- 0.11 l) and nine ARDS patients (mean age 57 +/- 6 years; mean lung injury score 2.8 +/- 0.1). MEASUREMENTS AND RESULTS: We measured hemodynamic and gas exchange parameters before NO inhalation (basal 1), during inhalation of 10 ppm NO (NO-10), and 20 min after NO was discontinued (in basal 2) in the ARDS group. In the COPD group, these parameters were measured before NO inhalation (basal 1), during different doses of inhaled NO (10, 20, and 30 ppm), and 20 min after NO was discontinued (basal 2). A positive response to NO was defined as a 20% increment in basal arterial partial pressure of oxygen (PaO2). MPAP and pulmonary vascular resistance (PVR) decreased significantly, while other hemodynamic parameters remained unchanged after NO-10 in both groups. Basal oxygenation was higher in the COPD group (PaO2/FIO2 (fractional inspired oxygen) 190 +/- 18 mmHg) than in the ARDS group (PaO2/FIO2 98 +/- 12 mmHg), (p < 0.01). After NO-10, PaO2/FIO2 increased (to 141 +/- 17 mmHg, p < 0.01) and Qva/Qt decreased (39 +/- 3 to 34 +/- 3%, p < 0.01) in the ARDS group. There were no changes in PaO2/FIO2 and Qva/Qt when the NO concentration was increased to 30 ppm in the COPD group. In both groups, a correlation was found between basal MPAP and basal PVR, and between the NO-induced decrease in MPAP and in PVR. The NO-induced increase in PaO2/FIO2 was not correlated with basal PaO2/FIO2. In the ARDS group, six of the nine patients (66%) responded to NO and in the COPD group, two of nine (22%) (p = 0.05). CONCLUSIONS: NO inhalation had similar effects on hemodynamics but not on gas exchange in ARDS and COPD patients, and this response probably depends on the underlying disease.