[Early determinants of acute kidney injury during experimental intra-abdominal sepsis]. / Determinantes precoces en el desarrollo de injuria renal aguda durante la sepsis abdominal experimental.

BACKGROUND: Sepsis-induced acute kidney injury (AKI) is an early and frequent organ dysfunction, associated with increased mortality. AIM: To evaluate the impact of macrohemodynamic and microcirculatory changes on renal function and histology during an experimental model of intra-abdominal sepsis. MATERIAL AND METHODS: In 18 anaesthetized pigs, catheters were installed to measure hemodynamic parameters in the carotid, right renal and pulmonary arteries. After baseline assessment and stabilization, animals were randomly divided to receive and intra-abdominal infusion of autologous feces or saline. Animals were observed for 18 hours thereafter. RESULTS: In all septic animals, serum lactate levels increased, but only eight developed AKI (66%). These animals had higher creatinine and interleukin-6 levels, lower inulin and para-aminohippurate clearance (decreased glomerular filtration and renal plasma flow), and a negative lactate uptake. Septic animals with AKI had lower values of mean end arterial pressure, renal blood flow and kidney perfusion pressure, with an associated increase in kidney oxygen extraction. No tubular necrosis was observed in kidney histology. CONCLUSIONS: The reduction in renal blood flow and renal perfusion pressure were the main mechanisms associated with AKI, but were not associated with necrosis. Probably other mechanisms, such as microcirculatory vasoconstriction and inflammation also contributes to AKI development.

Determinantes precoces en el desarrollo de injuria renal aguda durante la sepsis abdominal experimental / Early determinants of acute kidney injury during experimental intra-abdominal sepsis

Background: Sepsis-induced acute kidney injury (AKI) is an early and frequent organ dysfunction, associated with increased mortality. Aim: To evaluate the impact of macrohemodynamic and microcirculatory changes on renal function and histology during an experimental model of intra-abdominal sepsis. Material and Methods: In 18 anaesthetized pigs, catheters were installed to measure hemodynamic parameters in the carotid, right renal and pulmonary arteries. After baseline assessment and stabilization, animals were randomly divided to receive and intra-abdominal infusion of autologous feces or saline. Animals were observed for 18 hours thereafter. Results: In all septic animals, serum lactate levels increased, but only eight developed AKI (66%). These animals had higher creatinine and interleukin-6 levels, lower inulin and para-aminohippurate clearance (decreased glomerular filtration and renal plasma flow), and a negative lactate uptake. Septic animals with AKI had lower values of mean end arterial pressure, renal blood flow and kidney perfusion pressure, with an associated increase in kidney oxygen extraction. No tubular necrosis was observed in kidney histology. Conclusions: The reduction in renal blood flow and renal perfusion pressure were the main mechanisms associated with AKI, but were not associated with necrosis. Probably other mechanisms, such as microcirculatory vasoconstriction and inflammation also contributes to AKI development.

[Controversies in massive pulmonary embolism]. / Controversias en tromboembolismo pulmonar masivo.

Massive pulmonary embolism (PE) is associated with high mortality. There is still a broad assortment of severity classifications for patients with PE, which affects the choice of therapies to use. The main clinical criteria for defining a PE as massive is systemic arterial hypotension, which depends on the extent of vascular obstruction and the previous cardiopulmonary status. Right ventricular dysfunction is an important pathogenic element to define the severity of patients and short term clinical prognosis. The recommended treatment is systemic thrombolysis, but in centers with experience and resources, radiological invasive therapies through catheters are useful alternatives that can be used as first choice tools in certain cases.

Controversias en tromboembolismo pulmonar masivo / Controversies in massive pulmonary embolism

Massive pulmonary embolism (PE) is associated with high mortality. There is still a broad assortment of severity classifications for patients with PE, which affects the choice of therapies to use. The main clinical criteria for defining a PE as massive is systemic arterial hypotension, which depends on the extent of vascular obstruction and the previous cardiopulmonary status. Right ventricular dysfunction is an important pathogenic element to define the severity of patients and short term clinical prognosis. The recommended treatment is systemic thrombolysis, but in centers with experience and resources, radiological invasive therapies through catheters are useful alternatives that can be used as first choice tools in certain cases.

Catastrophic respiratory failure from tuberculosis pneumonia: Survival after prolonged extracorporeal membrane oxygenation support.

Tuberculosis (TB) is an uncommon cause of severe respiratory failure, even in highly endemic regions. Mortality in cases requiring mechanical ventilation (MV) varies between 60 and 90%. The use of extracorporeal membrane oxygenation (ECMO) is not frequently needed in TB. We report the case of a 24 year old woman diagnosed with bilateral pneumonia that required MV and intensive care, patient was managed with prone ventilation for 48 h, but persisted in refractory hypoxemia. Etiological study was only positive for mycobacterium tuberculosis. As a rescue therapy arterio-venous extracorporeal CO2 removal was started and lased for 4 days, but fails to support the patient due to greater impairment of oxygenation. Veno-venous ECMO was then initiated, thus normalizes gas exchanged and allows lungs to rest. ECMO was maintained for 36 days, with two episodes of serious complication treated successfully. Given the absence of clinical improvement and the lack of nosocomial infection, at 42-day of ICU stay methylprednisolone 250 mg daily for 4 days was started, since secondary organizing pneumonia associated with TB was suspected. Thereafter progressive improvement in pulmonary mechanics and reduction of pulmonary opacities was observed, allowing the final withdrawal of ECMO. Percutaneous tracheostomy was performed and the patient remained connected until her transfer to her base hospital at day 59 of admission to our unit. The tracheostomy was removed prior to hospital discharge, and the patient is today at home. Prolonged ECMO support is a useful and potentially successful tool in catastrophic respiratory failure caused by TB.

Tromboembolismo pulmonar: estratificación de riesgo y dilemas terapéuticos / Risk stratification of pulmonary thromboembolism

Background: The prognosis of pulmonary thromboembolism (PE) is related to the cardiopulmonary reserve of the patient and the magnitude of the embolus that impacts pulmonary circulation. The presence of hemodynamic instability (shock) stratifies a group of patients with high mortality, which should be treated with thrombolysis. Patients without shock but with right ventricular dysfunction can have a dismal evolution and should be managed aggressively. CAT scan, echocardiography and serum markers can be of value to define patients with a higher mortality. The available evidence to define the best diagnostic and therapeutic strategy is scanty, controversial and inconclusive. A good combination of clinical, imaging and biological markers should be defined to identify those patients without shock but with a high rate of complications and mortality, that could benefit from aggressive treatments.

Natriuretic peptide type-B can be a marker of reperfusion in patients with pulmonary thromboembolism subjected to invasive treatment.

This study was intended to investigate changes in cardiac biomarkers and pulmonary hemodynamic effects of invasive treatment in patients with intermediate-risk (hemodynamic stability with evidence of right ventricle dysfunction and/or myocardial injury) pulmonary embolism. Also, to also evaluate if natriuretic peptide type-B (NT-proBNP) plasma levels are associated with right ventricle function and pulmonary arterial pressures. Interventional study: Fourteen normotensive adult patients with acute and radiologically massive pulmonary embolism plus positive biomarkers and evidences of right ventricle dysfunction underwent invasive pulmonary angiography for invasive treatment consisting on mechanical thrombus fragmentation and catheter-directed intrathrombus thrombolysis. Angiography was repeated after 12-24 h to reevaluate perfusion status. Plasma biomarkers were monitored before and 8-h after intervention. Biomarkers were initially elevated in all patients. Eleven patients (78.6%) exhibited significant angiographic reperfusion. NT-proBNP and mean pulmonary arterial pressure decreased significantly in all of them [3693 (1803, 8862) to 1951 (1309, 7918) pg/ml; P = 0.008) and 40.0 (24.0, 46.0) to 22.0 (14.0, 27.0) mmHg; P = 0.003, respectively]. No significant variation was observed in troponin-T levels. In patients with high-risk pulmonary embolism, NT-proBNP plasma levels experience rapid and significant reduction after successful invasive treatment. In pulmonary embolism, serial measurements of NT-proBNP could be useful as a tracking tool to assess the success or failure of the thrombolytic treatment.

[Risk stratification of pulmonary thromboembolism]. / Tromboembolismo pulmonar: estratificación de riesgo y dilemas terapéuticos.

The prognosis of pulmonary thromboembolism (PE) is related to the cardiopulmonary reserve of the patient and the magnitude of the embolus that impacts pulmonary circulation. The presence of hemodynamic instability (shock) stratifies a group of patients with high mortality, which should be treated with thrombolysis. Patients without shock but with right ventricular dysfunction can have a dismal evolution and should be managed aggressively. CAT scan, echocardiography and serum markers can be of value to define patients with a higher mortality. The available evidence to define the best diagnostic and therapeutic strategy is scanty, controversial and inconclusive. A good combination of clinical, imaging and biological markers should be defined to identify those patients without shock but with a high rate of complications and mortality, that could benefit from aggressive treatments.

Resultados preliminares y factibilidad del mini lavado bronco-alveolar en pacientes cursando falla respiratoria severa / Mini bronchoalveolar lavage in patients with severe respiratory failure

Background: To recognize the etiological agent responsible for severe acute respiratory failure (ARF) in patients in mechanical ventilation (MV) is important to determine their treatment and prognosis, and to avoid the excessive use of antibiotics. Mini bronchoalveolar lavage (mini BAL) is a blind, non bronschoscopic procedure, used to obtain samples from the lower respiratory tract from patients on mechanical ventilation (MV). Aim: To assess the feasibility, complications and preliminary results of mini BAL among patients with severe ARF on MV. Material and Methods: Prospective study in 17 patients with acute lung injury (ALI ) or acute respiratory distess syndrome (ARDS) on MV and with negative conventional microbiological studies. Mini BAL was performed using standardized protocols. Hemodynamic and respiratory parameters where measured before and after the procedure. Samples obtained were sent to quantitative cultures. Results: At baseline: APACHE II score of 22 ± 6,7, PaO2/FiO2 ratio was 176.6 ± 48.6 and the oxygenation index was 9.74 ± 3.78. All procedures were performed by an ICU resident. Thirty five percent of the procedures had positive cultures and no complications related to the procedures were reported. The procedure lasted an average of 12 minutes and the instilled and rescued volume were 60 ml and 19.6 ml, respectively. There were no significant differences between hemodynamic and respiratory variables before and after the procedure. Conclusions: Mini BAL is a safe, fast and easy technique for obtaining samples from the inferior airway in patients with ALI or ARDS on MV.

[Mini bronchoalveolar lavage in patients with severe respiratory failure]. / Resultados preliminares y factibilidad del mini lavado bronco-alveolar en pacientes cursando falla respiratoria severa.

BACKGROUND: To recognize the etiological agent responsible for severe acute respiratory failure (ARF) in patients in mechanical ventilation (MV) is important to determine their treatment and prognosis, and to avoid the excessive use of antibiotics. Mini bronchoalveolar lavage (mini BAL) is a blind, non bronchoscopic procedure, used to obtain samples from the lower respiratory tract from patients on mechanical ventilation (MV). AIM: To assess the feasibility, complications and preliminary results of mini BAL among patients with severe ARF on MV. MATERIAL AND METHODS: Prospective study in 17 patients with acute lung injury (ALI ) or acute respiratory distress syndrome (ARDS) on MV and with negative conventional microbiological studies. Mini BAL was performed using standardized protocols. Hemodynamic and respiratory parameters where measured before and after the procedure. Samples obtained were sent to quantitative cultures. RESULTS: At baseline: APACHE II score of 22 ± 6,7, PaO2/FiO2 ratio was 176.6 ± 48.6 and the oxygenation index was 9.74 ± 3.78. All procedures were performed by an ICU resident. Thirty five percent of the procedures had positive cultures and no complications related to the procedures were reported. The procedure lasted an average of 12 minutes and the instilled and rescued volume were 60 ml and 19.6 ml, respectively. There were no significant differences between hemodynamic and respiratory variables before and after the procedure. CONCLUSIONS: Mini BAL is a safe, fast and easy technique for obtaining samples from the inferior airway in patients with ALI or ARDS on MV.

[Prevalence of severe sepsis in intensive care units. A national multicentric study]. / Prevalencia de sepsis grave en las Unidades de Cuidado Intensivo. Primer estudio nacional multicéntrico.

BACKGROUND: Severe sepsis (SS) is the leading cause of death in the Intensive Care Units (ICU). AIM: To study the prevalence of SS in Chilean ICUs. MATERIAL AND METHODS: An observational, cross-sectional study using a predesigned written survey was done in all ICUs of Chile on April 21st, 2004. General hospital and ICU data and the number of hospitalized patients in the hospital and in the ICU at the survey day, were recorded. Patients were followed for 28 days. RESULTS: Ninety four percent of ICUs participated in the survey. The ICU occupation index was 66%. Mean age of patients was 57.7+/-18 years and 59% were male, APACHE II score was 15+/-7.5 and SOFA score was 6+/-4. SS was the admission diagnosis of 94 of the 283 patients (33%) and 38 patients presented SS after admission. On the survey day, 112 patients fulfilled SS criteria (40%). APACHE II and SOFA scores were significantly higher in SS patients than in non SS patients. Global case-fatality ratio at 28 days was 15.9% (45/283). Case-fatality ratio in patients with or without SS at the moment of the survey was 26.7% (30/112) and 8.7% (17/171), respectively p <0.05. Thirteen percent of patients who developed SS after admission, died. Case-fatality ratios for patients with SS from Santiago and the other cities were similar, but APACHE II score was significantly higher in patients from Santiago. In SS patients, the independent predictors of mortality were SS as cause of hospital admission, APACHE II and SOFA scores. Ninety nine percent of SS patients had a known sepsis focus (48% respiratory and 30% abdominal). Eighty five patients that presented SS after admission, had a respiratory focus. CONCLUSIONS: SS is highly prevalent in Chilean ICUs and represents the leading diagnosis at admission. SS as cause of hospitalization, APACHE II and SOFA scores were independent predictors of mortality.

[Thiazide induced acute pulmonary edema: report of one case]. / Edema pulmonar agudo por uso de tiazidas, ¿existe falla cardíaca?: Comunicación de un caso.

Acute pulmonary edema caused by thiazides is uncommon and of difficult diagnosis. It is considered an idiosyncratic reaction and the physiopathology or cardiac function changes are not well known. We report a 60 year-old female with a thiazide induced acute pulmonary edema who was followed with serial measurements of type B n-terminal natriuretic peptide fraction as marker for cardiac dysfunction. There was a significant elevation of the peptide, not associated to evidences of ventricular dysfunction. Its normalization paralleled the resolution of the clinical picture.

[Comparison of cardiac output measurement in critical patients using transesophageal Doppler or thermodilution: a preliminary report]. / Determinación y análisis comparativo de gasto cardíaco en enfermos críticos mediante Doppler transesofágico y termodilución en bolos: experiencia preliminar.

BACKGROUND: Cardiac output can be measured non invasively by transesophageal Doppler. This is an alternative to measure it by thermodilution with a catheter in the pulmonary artery. AIM: To compare both methods of cardiac output measurement. MATERIAL AND METHODS: Simultaneous measurement of cardiac output by transesophageal Doppler and thermodilution with a catheter in the pulmonary artery in four male critical patients, aged 60+/-12 years, hospitalized in a University Hospital. The Bland and Altman method to compare the concordance between two measurements, was used. RESULTS: Forty measurements were performed. The results of both methods had a correlation coefficient of 0.98. According to the Bland and Altman method, the difference between both methods was -0.5 L with a precision of 0.52 L/min (95% confidence interval -1.51 to 0.52 L/min). Considering that a change between two sequential measurements is considered significant when the difference is more than 15%, both measurements agreed in 83% of cases, that there was a change in cardiac output. CONCLUSIONS: Transesophageal Doppler is a promising non invasive technique to measure cardiac output in critical care patients. It becomes a valid alternative to the thermodilution technique. This preliminary experience must be confirmed in a larger series.

Embolia por líquido amniótico: una puesta al día a propósito de un caso / Amniotic fluid embolism: a case report and update

Se presenta el caso clínico de una mujer de 17 años de edad, cursando un embarazo de 33 semanas, que ingresa al hospital por trabajo de parto prematuro. Se descartó infección de la unidad feto-placentaria y materna. Se manejo mediante inhibición del trabajo de parto con fenoterol e inducción de madurez pulmonar con corticoides. Evolucionó satisfactoriamente. En el puerperio inmediato, la madre presenta cuadro de insuficiencia respiratoria aguda, por lo que debe ser trasladada a Unidad de Cuidados Intensivos donde es estabilizada inicialmente con oxígeno 100 por ciento por mascarilla de recirculación, diuréticos e infusión continua de nitroglicerina. Se realizó angiografía pulmonar por tomografía axial computarizada, que evidenció la presencia de imágenes compatibles con embolia por líquido amniótico. El diagnóstico se planteó una vez excluidos sistemáticamente los diagnósticos de edema pulmonar agudo cardiogénico, tromboembolismo pulmonar, aspiración bronquial y neumonía. La paciente evolucionó satisfactoriamente, disminuyendo paulatinamente sus requerimientos de oxígeno, siendo dada de alta días más tarde, asintomática.

Utilidad del ecocardiograma y de marcadores séricos en la estratificación de riesgo en pacientes cursando con embolia pulmonar submasiva / Utility of echocardiogram and serum markers in the risk stratification in patients attending with submassive pulmonary embolism

Los pacientes que cursan tromboembolismo, dependiendo de su severidad, pueden recibir variados tratamientos no exentos de efectos adversos. Existe, por lo tanto, la necesidad de estratificar riesgo -magnitud- mortalidad con criterios que le permitan al clínico tomar las mejores decisiones. En este artículo se pretende establecer un sistema de aproximación al tromboembolismo pulmonar de acuerdo a la información hasta ahora disponible.

[Hantavirus cardiopulmonary syndrome: utility of the PICCO(Pulse contour cardiac output) system for monitoring]. / Síndrome cardiopulmonar por Hantavirus: utilidad de la monitorización con el sistema PiCCO.

We report a 68 years old man, farmer from the metropolitan region, admitted with a Hantavirus Cardiopulmonary Syndrome. The diagnosis was made using serologic test and was later confirmed by the Public Health Institute. He evolved to an early multiple organ failure, requiring high concentrations of oxygen and invasive ventilatory assistance, vasopressor drugs and renal replacement therapy. Swan Ganz and PiCCO were used simultaneously for hemodynamic monitoring. Treatment consisted in global support therapy, antimicrobial therapy and systemic corticosteroids. Intrathoracic blood volume was a more reliable parameter than pulmonary capillary wedge pressure for the assessment of preload. As expected in situations of increased vascular permeability, there was an increase in extravascular lung water. There was a good correlation between extravascular lung water and oxygenation parameters (PaO2/FiO2 and oxygenation index). PiCCO system may become a helpful tool in the management of patients with Hantavirus Cardiopulmonary Syndrome.

[Hemodynamic impact of positive end expiratory pressure (PEEP) during severe respiratory failure: present view]. / Impacto hemodinámico de la presión positiva de fin de espiración (PEEP) durante la falla respiratoria grave: visión actual.

Bedside evaluation of pulmonary mechanics and thoracic computed axial tomography have changed the ventilatory management of patients suffering an acute respiratory failure caused by adult respiratory distress syndrome (ARDS). Mortality has been reduced limiting tidal volumes, which avoids alveolar overdistention and by the use of positive end expiratory pressure (PEEP), that reduces the damage caused by cyclical alveolar collapse-reopening. Nowadays, it is well known that inappropriate mechanical ventilation enhances lung damage caused by the underlying disease. However, the optimal adjustment of PEEP is not yet established. Usually, it is not easy to achieve an equilibrium between an optimal lung recruitment without producing alveolar overdistention and hemodynamic adverse effects such as hypotension and reduction of cardiac output. This paper reviews the interactions between heart and lung.