[Clinical outcomes in cancer patients hospitalized with COVID-19]. / Evolución clínica de pacientes internados con cáncer e infección por COVID-19.

Cancer patients are exposed to more complications from COVID-19 than non-cancer patients. We report a cohort of 74 cancer patients (87.8% with solid neoplasia and 12.2% with hematological diseases) with COVID-19 infection admitted to a tertiary medical cancer center in Argentina. Pulmonary infiltrates were diagnosed at admission in 78.3% (N = 58) of the cases. COVID-19 infection was hospital-acquired in 20 (27.0%) patients. Thirty-nine patients (52.7%) received anticancer therapy within the 30 days prior to COVID-19 diagnosis; one was on radiation therapy. Twenty-four (32.4%) patients were admitted in the intensive care unit (ICU) and 18 (75.0%) required mechanical ventilation. All cause in-hospital mortality was 32.4% (N = 24) and ICU mortality was 62.5% (N = 15). Mortality under mechanical ventilation was 72.2% (N = 13). In the univariate analysis age, neutrophil count, neutrophil/lymphocyte index, D-dimer, ferritin, smoking, and nosocomial acquired infection were associated with in-hospital mortality. There were no statistically significant differences in mortality related to disease stage for solid tumors, neither cancer treatment within 30 days of COVID-19 diagnosis. Age and smoking were associated with mortality in the multivariate analysis. The adjusted odds ratios (95 CI) for age = 65 years and smoking were 8.87 (1.35-58.02) and 8.64 (1.32 - 56.64), respectively. Our experience can be useful for other institutions that assist cancer patients during the pandemic.

Los pacientes con cáncer y COVID-19 tienen más complicaciones que la población general. Comunicamos una cohorte de 74 pacientes con cáncer y COVID-19 internados en una institución oncológica. El 87.8% tenía diagnóstico de tumores sólidos y 12.2% oncohematológicos. Entre los tumores sólidos, el 61.5% presentó enfermedad metastásica. El 78.3% (N = 58) tenía infiltrados pulmonares al diagnóstico de COVID-19. La infección fue intrahospitalaria en 20 pacientes. Habían recibido tratamiento antineoplásico dentro de los 30 días anteriores al diagnóstico 39 pacientes (52.7%); uno se encontraba recibiendo radioterapia. Veinticuatro pacientes (32.4%) se derivaron a terapia intensiva (UTI) y 18 (75%) de ellos requirieron asistencia respiratoria mecánica (ARM). La mortalidad general durante la internación fue 32.4% (N = 24). La mortalidad en UTI fue 62.5% (N = 15). La mortalidad en ARM fue 72.2% (N = 13). La edad, recuento de neutrófilos, índice neutrófilo/linfocito, dímero D, ferritina, tabaquismo y haber adquirido la infección durante la internación resultaron estadísticamente significativos en el análisis univariado para mortalidad. No hallamos diferencias en mortalidad por estadio de enfermedad, en los pacientes con tumores sólidos, ni por haber recibido tratamiento antineoplásico dentro de los 30 días del diagnóstico de COVID-19. En el análisis multivariado con el modelo de regresión logística, solo la edad y el tabaquismo fueron predictores de mortalidad. Los odds ratios (IC 95) ajustados para la edad =65 años y el tabaquismo fueron 8.87 (1.35-58.02) y 8.64 (1.32-56.64), respectivamente. Este trabajo puede resultar de utilidad para instituciones polivalentes que asistan pacientes oncológicos durante la pandemia.

Evolución clínica de pacientes internados con cáncer e infección por COVID-19 / Clinical outcomes in cancer patients hospitalized with COVID-19

Resumen Los pacientes con cáncer y COVID-19 tienen más complicaciones que la población general. Comunicamos una cohorte de 74 pacientes con cáncer y COVID-19 internados en una institución on cológica. El 87.8% tenía diagnóstico de tumores sólidos y 12.2% oncohematológicos. Entre los tumores sólidos, el 61.5% presentó enfermedad metastásica. El 78.3% (N = 58) tenía infiltrados pulmonares al diagnóstico de COVID-19. La infección fue intrahospitalaria en 20 pacientes. Habían recibido tratamiento antineoplásico den tro de los 30 días anteriores al diagnóstico 39 pacientes (52.7%); uno se encontraba recibiendo radioterapia. Veinticuatro pacientes (32.4%) se derivaron a terapia intensiva (UTI) y 18 (75%) de ellos requirieron asistencia respiratoria mecánica (ARM). La mortalidad general durante la internación fue 32.4% (N = 24). La mortalidad en UTI fue 62.5% (N = 15). La mortalidad en ARM fue 72.2% (N = 13). La edad, recuento de neutrófilos, índice neutrófilo/linfocito, dímero D, ferritina, tabaquismo y haber adquirido la infección durante la internación resultaron estadísticamente significativos en el análisis univariado para mortalidad. No hallamos diferencias en mortalidad por estadio de enfermedad, en los pacientes con tumores sólidos, ni por haber recibido tratamiento antineoplá sico dentro de los 30 días del diagnóstico de COVID-19. En el análisis multivariado con el modelo de regresión logística, solo la edad y el tabaquismo fueron predictores de mortalidad. Los odds ratios (IC 95) ajustados para la edad ≥65 años y el tabaquismo fueron 8.87 (1.35-58.02) y 8.64 (1.32-56.64), respectivamente. Este trabajo puede resultar de utilidad para instituciones polivalentes que asistan pacientes oncológicos durante la pandemia.

Abstract Cancer patients are exposed to more complications from COVID-19 than non-cancer patients. We report a cohort of 74 cancer patients (87.8% with solid neoplasia and 12.2% with hematological diseases) with COVID-19 infection admitted to a tertiary medical cancer center in Argentina. Pulmonary infiltrates were diagnosed at admission in 78.3% (N = 58) of the cases. COVID-19 infection was hospital-acquired in 20 (27.0%) patients. Thirty-nine patients (52.7%) received anticancer therapy within the 30 days prior to COVID-19 diagnosis; one was on radiation therapy. Twenty-four (32.4%) patients were admitted in the intensive care unit (ICU) and 18 (75.0%) required mechanical ventilation. All cause in-hospital mortality was 32.4% (N = 24) and ICU mortality was 62.5% (N = 15). Mortality under me chanical ventilation was 72.2% (N = 13). In the univariate analysis age, neutrophil count, neutrophil/lymphocyte index, D-dimer, ferritin, smoking, and nosocomial acquired infection were associated with in-hospital mortality. There were no statistically significant differences in mortality related to disease stage for solid tumors, neither cancer treatment within 30 days of COVID-19 diagnosis. Age and smoking were associated with mortality in the multivariate analysis. The adjusted odds ratios (95 CI) for age ≥ 65 years and smoking were 8.87 (1.35-58.02) and 8.64 (1.32 - 56.64), respectively. Our experience can be useful for other institutions that assist cancer patients during the pandemic.

Exhalatory dynamic interactions between patients connected to a shared ventilation device.

In this work a shared pressure-controlled ventilation device for two patients is considered. By the use of different valves incorporated to the circuit, the device enables the restriction of possible cross contamination and the individualization of tidal volumes, driving pressures, and positive end expiratory pressure PEEP. Possible interactions in the expiratory dynamics of different pairs of patients are evaluated in terms of the characteristic exhalatory times. These characteristic times can not be easily established using simple linear lumped element models. For this purpose, a 1D model using the Hydraulic and Mechanical libraries in Matlab Simulink was developed. In this sense, experiments accompany this study to validate the model and characterize the different valves of the circuit. Our results show that connecting two patients in parallel to a ventilator always resulted in delays of time during the exhalation. The size of this effect depends on different parameters associated with the patients, the circuit and the ventilator. The dynamics of the exhalation of both patients is determined by the ratios between patients exhalatory resistances, compliances, driving pressures and PEEPs. Adverse effects on exhalations became less noticeable when respiratory parameters of both patients were similar, flow resistances of valves added to the circuit were negligible, and when the ventilator exhalatory valve resistance was also negligible. The asymmetries of driving pressures, compliances or resistances exacerbated the possibility of auto-PEEP and the increase in relaxation times became greater in one patient than in the other. In contrast, exhalatory dynamics were less sensitive to the ratio of PEEP imposed to the patients.

High versus low positive end-expiratory pressure (PEEP) levels for mechanically ventilated adult patients with acute lung injury and acute respiratory distress syndrome.

BACKGROUND: In patients with acute lung injury (ALI) and acute respiratory distress syndrome (ARDS), mortality remains high. These patients require mechanical ventilation, which has been associated with ventilator-induced lung injury. High levels of positive end-expiratory pressure (PEEP) could reduce this condition and improve patient survival. This is an updated version of the review first published in 2013. OBJECTIVES: To assess the benefits and harms of high versus low levels of PEEP in adults with ALI and ARDS. SEARCH METHODS: For our previous review, we searched databases from inception until 2013. For this updated review, we searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, LILACS, and the Web of Science from inception until May 2020. We also searched for ongoing trials (www.trialscentral.org; www.clinicaltrial.gov; www.controlled-trials.com), and we screened the reference lists of included studies. SELECTION CRITERIA: We included randomised controlled trials that compared high versus low levels of PEEP in ALI and ARDS participants who were intubated and mechanically ventilated in intensive care for at least 24 hours. DATA COLLECTION AND ANALYSIS: Two review authors assessed risk of bias and extracted data independently. We contacted investigators to identify additional published and unpublished studies. We used standard methodological procedures expected by Cochrane. MAIN RESULTS: We included four new studies (1343 participants) in this review update. In total, we included 10 studies (3851 participants). We found evidence of risk of bias in six studies, and the remaining studies fulfilled all criteria for low risk of bias. In eight studies (3703 participants), a comparison was made between high and low levels of PEEP, with the same tidal volume in both groups. In the remaining two studies (148 participants), the tidal volume was different between high- and low-level groups. In the main analysis, we assessed mortality occurring before hospital discharge only in studies that compared high versus low PEEP, with the same tidal volume in both groups. Evidence suggests that high PEEP may result in little to no difference in mortality compared to low PEEP (risk ratio (RR) 0.97, 95% confidence interval (CI) 0.90 to 1.04; I² = 15%; 7 studies, 3640 participants; moderate-certainty evidence). In addition, high PEEP may result in little to no difference in barotrauma (RR 1.00, 95% CI 0.64 to 1.57; I² = 63%; 9 studies, 3791 participants; low-certainty evidence). High PEEP may improve oxygenation in patients up to the first and third days of mechanical ventilation (first day: mean difference (MD) 51.03, 95% CI 35.86 to 66.20; I² = 85%; 6 studies, 2594 participants; low-certainty evidence; third day: MD 50.32, 95% CI 34.92 to 65.72; I² = 83%; 6 studies, 2309 participants; low-certainty evidence) and probably improves oxygenation up to the seventh day (MD 28.52, 95% CI 20.82 to 36.21; I² = 0%; 5 studies, 1611 participants; moderate-certainty evidence). Evidence suggests that high PEEP results in little to no difference in the number of ventilator-free days (MD 0.45, 95% CI -2.02 to 2.92; I² = 81%; 3 studies, 1654 participants; low-certainty evidence). Available data were insufficient to pool the evidence for length of stay in the intensive care unit. AUTHORS' CONCLUSIONS: Moderate-certainty evidence shows that high levels compared to low levels of PEEP do not reduce mortality before hospital discharge. Low-certainty evidence suggests that high levels of PEEP result in little to no difference in the risk of barotrauma. Low-certainty evidence also suggests that high levels of PEEP improve oxygenation up to the first and third days of mechanical ventilation, and moderate-certainty evidence indicates that high levels of PEEP improve oxygenation up to the seventh day of mechanical ventilation. As in our previous review, we found clinical heterogeneity - mainly within participant characteristics and methods of titrating PEEP - that does not allow us to draw definitive conclusions regarding the use of high levels of PEEP in patients with ALI and ARDS. Further studies should aim to determine the appropriate method of using high levels of PEEP and the advantages and disadvantages associated with high levels of PEEP in different ARDS and ALI patient populations.

Ventilator-associated pneumonia involving Aspergillus flavus in a patient with coronavirus disease 2019 (COVID-19) from Argentina.

Coronavirus disease 2019 (COVID-19), caused by the novel coronavirus SARS-CoV-2, emerged in Wuhan, China, in December 2019 and rapidly spread around the world. Invasive aspergillosis has been reported as a complication of severe influenza pneumonia among intensive care patients. Similarities between COVID-19 and influenza pneumonia, together with limited published case series, suggest that aspergillosis may be an important complication of COVID-19. This report describes a case of ventilator-associated pneumonia involving Aspergillus flavus in a patient with COVID-19 from Buenos Aires, Argentina.

Is a strategy based on routine endotracheal cultures the best way to prescribe antibiotics in ventilator-associated pneumonia?

OBJECTIVES: The objectives of this study were to evaluate if a strategy based on routine endotracheal aspirate (ETA) cultures is better than using the American Thoracic Society/Infectious Diseases Society of America (ATS/IDSA) guidelines to prescribe antimicrobials in ventilator-associated pneumonia (VAP). METHODS: This was a prospective, observational, cohort study conducted in a 15-bed ICU and comprising 283 patients who were mechanically ventilated for ≥48 h. Interventions included twice-weekly ETA; BAL culture was done if VAP was suspected. BAL (collected at the time of VAP) plus ETA cultures (collected≤7 days before VAP) (n=146 different pairs) were defined. We compared two models of 10 days of empirical antimicrobials (ETA-based vs ATS/IDSA guidelines-based strategies), analyzing their impact on appropriateness of therapy and total antimicrobial-days, using the BAL result as the standard for comparison. RESULTS: Complete ETA and BAL culture concordance (identical pathogens or negative result) occurred in 52 pairs; discordance (false positive or false negative) in 67, and partial concordance in two. ETA predicted the etiology in 62.4% of all pairs, in 74.0% of pairs if ETA was performed≤2 days before BAL, and in 46.2% of pairs if ETA was performed 3 to 7 days before BAL (P=.016). Strategies based on the ATS/IDSA guidelines and on ETA results led to appropriate therapy in 97.9% and 77.4% of pairs, respectively (P<.001). The numbers of antimicrobial-days were 1,942 and 1,557 for therapies based on ATS/IDSA guidelines and ETA results, respectively (P<.001). CONCLUSIONS: The ATS/IDSA guidelines-based approach was more accurate than the ETA-based strategy for prescribing appropriate, initial, empirical antibiotics in VAP, unless a sample was available≤2 days of the onset of VAP. The ETA-based strategy led to fewer days on prescribed antimicrobials.

Traqueobronquitis asociada al ventilador (TAV), implicancias del diagnostico clinico y microbiologico en una cohorte de pacientes en ventilacion mecanica / Ventilator associated tracheobronchitis (VAT), implications of clinical and microbiological diagnosis in a cohort of mechanical ventilated patients

Tratar con antibioticos una TAV, proceso intermedio entre colonizacion y neumonia asociada al ventilador (NAV), reduciria la incidencia de NAV y sus consecuencias. Metodos: seguimiento clinico diario y cultivos cuantitativos rutinarios de aspirado traqueal (CRAT) bisemanales hasta el destete en 323 pacientes en ventilacion mecanica. Cuando se sospecho clinicamente infeccion (2/3 criterios), si habia infiltrado radiografico nuevo, se diagnostico NAV y se practico lavado broncoalveolar (LBA) y sin infiltrado nuevo, se diagnostico TAV, se consideraron los aislamientos del LBA positivos (¡Ý 104 unidades formadoras de colonias (ufc)/ml) para la NAV) y del CRAT positivos (¡Ý 103 y < 106 ufc/ml (bajo recuento) y ¡Ý 106 ufc/ml (alto recuento)) para TAV. Resultados: 443 de 2.309 radiografias mostraban ausencia de infiltrado o infiltrado difuso estable; 92 cumplian criterios de TAV, 13 de estas, 12 con CRAT ¡Ý 106 ufc/ml, tuvieron una NAV en los siguientes 3 dias (12 con cultivo de LBA ¡Ý104 ufc/ml). En estas NAV, 11/15 (73.3%) de los pat¨®genos coincidian con los de la TAV precedente. Desde otro punto de vista, 10 TAVs ocurrieron durante la semana posterior a una NAV, solo 4/12(33.3%) patogenos de estas coincidian con los de la TAV, p=0.045 comparando con TAV precediendo a NAV. Setenta TAVs no tuvieron relacion temporal con NAVs. Discusion: este estudio sugiere que tratar con antibioticos las TAVs podria prevenir una NAV en 14% de los casos, exponiendo a un uso innecesario al 86%, lo cual limitaria fuertemente la conveniencia de tratar las TAVs para prevenir las NAVs.

The ventilator associated tracheobronchitis (VAT) is a process between airway colonization and ventilator-associated pneumonia (VAP). The antimicrobial therapy of VAT wouldreduce the incidence of VAP and its consequences. Methods: Daily follow up and twice a week routine quantitative culture of endotracheal aspirates (CETA) up to weaning were performed in 323 mechanically ventilated patients.When a lower respiratory tract infection was suspected (2/3 clinical criteria), if a new radiographic inf¨ªltrate was present, VAP was diagnosed and a bronchoalveolar lavage (BAL) culture was performed; if a radiographic infiltrate was absent, VAT was diagnosed. The bacteriological criteria for diagnosis were a BAL culture positive (¡Ý 104 colony forming units - cfu/ml) for VAP and a CETA positive culture (low count from ¡Ý 103 to < 106 cfu/ml and high count ¡Ý 106 ufc/ml) for VAT. Results: In 443 of 2,309 radiographs an infiltrate was absent or was diffuse and stable; 92 of them met diagnostic clinical criteria for VAT. In 13 (12 with CETA culture ¡Ý 106 cfu/ml), a VAP episode happened during the following 3 days (12 with BAL culture ¡Ý 104 cfu/ml). In 11/15 (73.3%) VAP cases, the isolated pathogens were the same that had been present in the preceding VAT episode. On the other side, ten episodes of VAT were diagnosed during the 7 days after the VAP. Only 4/12 (33.3%) isolated pathogens were the same than those isolated in the VAT preceding the VAP, p=0.045. Seventy VATs had not any temporal relationship with episodes of VAP. Discusion: This study suggests that antimicrobial therapy could prevent a VAP in 14% of the TAV cases. Therefore, exposure to antibiotics was unnecessary in 86% of cases. This finding could represent a severe limitation to the recommendation of treating TAVs with antibiotics to prevent VAPs.

Traqueobronquitis asociada al ventilador (TAV), implicancias del diagnostico clinico y microbiologico en una cohorte de pacientes en ventilacion mecanica / Ventilator associated tracheobronchitis (VAT), implications of clinical and microbiological diagnosis in a cohort of mechanical ventilated patients

Tratar con antibioticos una TAV, proceso intermedio entre colonizacion y neumonia asociada al ventilador (NAV), reduciria la incidencia de NAV y sus consecuencias. Metodos: seguimiento clinico diario y cultivos cuantitativos rutinarios de aspirado traqueal (CRAT) bisemanales hasta el destete en 323 pacientes en ventilacion mecanica. Cuando se sospecho clinicamente infeccion (2/3 criterios), si habia infiltrado radiografico nuevo, se diagnostico NAV y se practico lavado broncoalveolar (LBA) y sin infiltrado nuevo, se diagnostico TAV, se consideraron los aislamientos del LBA positivos (í¦ 104 unidades formadoras de colonias (ufc)/ml) para la NAV) y del CRAT positivos (í¦ 103 y < 106 ufc/ml (bajo recuento) y í¦ 106 ufc/ml (alto recuento)) para TAV. Resultados: 443 de 2.309 radiografias mostraban ausencia de infiltrado o infiltrado difuso estable; 92 cumplian criterios de TAV, 13 de estas, 12 con CRAT í¦ 106 ufc/ml, tuvieron una NAV en los siguientes 3 dias (12 con cultivo de LBA í¦104 ufc/ml). En estas NAV, 11/15 (73.3%) de los pat¿«genos coincidian con los de la TAV precedente. Desde otro punto de vista, 10 TAVs ocurrieron durante la semana posterior a una NAV, solo 4/12(33.3%) patogenos de estas coincidian con los de la TAV, p=0.045 comparando con TAV precediendo a NAV. Setenta TAVs no tuvieron relacion temporal con NAVs. Discusion: este estudio sugiere que tratar con antibioticos las TAVs podria prevenir una NAV en 14% de los casos, exponiendo a un uso innecesario al 86%, lo cual limitaria fuertemente la conveniencia de tratar las TAVs para prevenir las NAVs. (AU)

The ventilator associated tracheobronchitis (VAT) is a process between airway colonization and ventilator-associated pneumonia (VAP). The antimicrobial therapy of VAT wouldreduce the incidence of VAP and its consequences. Methods: Daily follow up and twice a week routine quantitative culture of endotracheal aspirates (CETA) up to weaning were performed in 323 mechanically ventilated patients.When a lower respiratory tract infection was suspected (2/3 clinical criteria), if a new radiographic inf¿¬ltrate was present, VAP was diagnosed and a bronchoalveolar lavage (BAL) culture was performed; if a radiographic infiltrate was absent, VAT was diagnosed. The bacteriological criteria for diagnosis were a BAL culture positive (í¦ 104 colony forming units - cfu/ml) for VAP and a CETA positive culture (low count from í¦ 103 to < 106 cfu/ml and high count í¦ 106 ufc/ml) for VAT. Results: In 443 of 2,309 radiographs an infiltrate was absent or was diffuse and stable; 92 of them met diagnostic clinical criteria for VAT. In 13 (12 with CETA culture í¦ 106 cfu/ml), a VAP episode happened during the following 3 days (12 with BAL culture í¦ 104 cfu/ml). In 11/15 (73.3%) VAP cases, the isolated pathogens were the same that had been present in the preceding VAT episode. On the other side, ten episodes of VAT were diagnosed during the 7 days after the VAP. Only 4/12 (33.3%) isolated pathogens were the same than those isolated in the VAT preceding the VAP, p=0.045. Seventy VATs had not any temporal relationship with episodes of VAP. Discusion: This study suggests that antimicrobial therapy could prevent a VAP in 14% of the TAV cases. Therefore, exposure to antibiotics was unnecessary in 86% of cases. This finding could represent a severe limitation to the recommendation of treating TAVs with antibiotics to prevent VAPs. (AU)

[Pathophysiology of shock. New perspectives]. / Fisiopatología del shock. Nuevas perspectivas.

Metabolic activity can be down-regulated throughout the reduction of mitochondrial population. Lowering O2 demand in cardiogenic, hemorrhagic and septic shock is here examined through clinical observations and trials. A decrease in the availability of O will be followed by reductions in mitochondrial population and, therefore, in a decrease in O2 demand. This response may lessen or prevent the acquisition of an O2 debt; until now, cornerstone in the pathophysiology of shock. The cost of this adaptation is less energy production, and the resulting energy deficit has been linked to multiple organ failure (MOF), a complication of acute inflammatory processes and shock. MOF is better tolerated than anaerobic metabolism and is potentially reversible if the triggering causes are reversed and the energy level is re-established through mitochondrial biogenesis.Decoupling of mitochondrial oxidative phosphorylation occurs in both experimental models and in clinical septic shock. In critical patients this phenomenon may be detected by an inordinate increase in VO2 in response to a therapeutically increased DO. This hipermetabolic stage can be mistakenly interpreted as the repayment phase of an O2 debt.

Fisiopatología del shock: Nuevas perspectivas / Pathophysiology of shock: New perspectives

La actividad metabólica puede modificarse mediante la regulación de la población mitocondrial en distintas enfermedades críticas. A través de observaciones y ensayos clínicos examinamos esta adaptación metabólica en el shock cardiogénico, hemorrágico y séptico. La caída de la disponibilidad de O2 (DO2) llevaría a una reducción de la población mitocondrial y consecuentemente a una disminución del consumo de O2 (VO2). Esta secuencia permite atenuar y aun evitar la adquisición de una deuda de O2, considerada hasta hoy base fundamental de la fisiopatología del shock. El costo de esta adaptación mitocondrial es menor energía disponible y el déficit energético resultante ha sido relacionado con la falla orgánica múltiple (FOM), importante complicación de diversos procesos inflamatorios agudos y estados de shock. La FOM es mejor tolerada que el metabolismo anaeróbico y es potencialmente reversible si se revierten las causas desencadenantes y se reestablece el nivel energético por medio de la biogénesis mitocondrial.El desacople de la fosforilación oxidativa mitocondrial ocurre tanto en diversos modelos experimentales de shock como así también en el shock séptico en el hombre. Esta alteración mitocondrial puede ser detectada por un aumento desmesurado del VO2 en respuesta al incremento terapéutico de la DO2. Este aumento de la actividad metabólica puede ser equívocamente interpretado como la fase de repago de una deuda de O2.

Metabolic activity can be down-regulated throughout the reduction of mitochondrial population. Lowering O2 demand in cardiogenic, hemorrhagic and septic shock is here examined through clinical observations and trials. A decrease in the availability of O2 will be followed by reductions in mitochondrial population and, therefore, in a decrease in O2 demand. This response may lessen or prevent the acquisition of an O2 debt; until now, cornerstone in the pathophysiology of shock. The cost of this adaptation is less energy production, and the resulting energy deficit has been linked to multiple organ failure (MOF), a complication of acute inflammatory processes and shock. MOF is better tolerated than anaerobic metabolism and is potentially reversible if the triggering causes are reversed and the energy level is re-established through mitochondrial biogenesis.Decoupling of mitochondrial oxidative phosphorylation occurs in both experimental models and in clinical septic shock. In critical patients this phenomenon may be detected by an inordinate increase in VO2 in response to a therapeutically increased DO2. This hipermetabolic stage can be mistakenly interpreted as the repayment phase of an O2 debt.

Interrelationship between oxygen-related variables in patients with acute myocardial infarction: an interpretative review.

The high mortality rate of cardiogenic shock in acute myocardial infarction (AMI) implies that debate over the correct haemodynamic management is still unresolved. The purpose of this review is to re-evaluate the reciprocal relationships between oxygen-related variables and response to treatment in a large number of patients with AMI. A MEDLINE search of reports published between 1970 and 2008 was performed. Twelve clinical reports including 453 patients with AMI and 989 sets of oxygen delivery and oxygen consumption expressed in ml min⁻¹ m⁻² and oxygen extraction ratio were selected. While processing this data, we found an early down-regulation in oxygen demand linked to a decrease in oxygen supply. This mechanism is also supported in some studies by a critically low oxygen uptake that was not associated with lactic acidosis.

[Death in an intensive care unit. Influence of life support withholding and withdrawal]. / La muerte en un servicio de terapia intensiva. Influencia de la abstención y retiro del soporte vital.

The influence of life support withholding and withdrawal on the deaths which occurred in an Intensive Care Unit (ICU) over a period of 32 months was analysed. Of 2640 patients admitted in ICU, one of the following five mutually exclusive categories was registered on the 548 patients who died: (i) complete treatment; (ii) complete treatment with non-resuscitation order (NRO); (iii) withholding of life-sustaining treatment; (iv) withdrawal of life-sustaining treatment; and (v) brain death. There was therapeutic limitation of life support in 45.6% of cases (n = 250), with an important majority of withholding (NRO and withholding) in 32.6% of cases, in comparison to withdrawal of life support (8.2% of cases). The comparative analysis with other statistic information suggests the existence of a similar global therapeutic limitation mean in communities with similar cultural background, even if there is a lower influence of life support withdrawal (8.2%) when compared to other countries regardless of their attitude towards the need to establish different degrees of control over technological resources applied to the critically ill. Further research should analyze the influence that moral perception of withdrawal as inconvenient in our society, has over our findings.

La muerte en un servicio de terapia intensiva: influencia de la abstencion y retiro del soporte vital / Death in an intensive care unit: influence of life support withholding and withdrawal

Se estudió la influencia de la abstención y retiro del soporte vital en la muerte ocurrida en un servicio de Terapia Intensiva durante un período de 32 meses. Sobre 2640 pacientes ingresados se registró la conducta terapéutica en 548 muertos, clasificando la misma en cinco categorías: (i) tratamiento completo, (ii) tratamiento completo con orden de no resucitación (ONR), (iii) abstención de soporte vital, (iv) retiro de soporte vital y (v) muerte cerebral. Hubo limitación terapéutica de soporte vital en el 45.6% (n= 250) con unpredominio importante de la abstención (ONR y abstención) en el 32.6% respecto del retiro de soporte vital (8.2%). Del estudio comparativo con otras estadísticas surge el hallazgo de un porcentaje global de limitación terapéutica media cercana a comunidades con una cultura similar, aunque con una incidencia de retiro (8.2%) manifiestamente inferior a la registrada en todos los países cualesquiera fuera su actitud frente a la necesidad de establecer diversos grados de control sobre el recurso tecnológico en el paciente crítico. Deberá indagarse la influencia que tiene la percepción moral del dejar de actuar, como un proceder inconveniente en nuestra sociedad, en los resultados observados.

The influence of life support withholding and withdrawal on the deaths which occurred in an Intensive Care Unit (ICU) over a period of 32 months was analysed. Of 2640 patients admitted in ICU, one of the following five mutually exclusive categories was registered on the 548 patients who died: (i) complete treatment; (ii) complete treatment with non-resuscitation order (NRO); (iii) withholding of life-sustaining treatment; (iv) withdrawal of life-sustaining treatment; and (v) brain death. There was therapeutic limitation of life support in 45.6% of cases (n=250), with an important majority of withholding (NRO and withholding) in 32.6% of cases, in comparison to withdrawal of life support (8.2% of cases). The comparative analysis with other statistic information suggests the existence of a similar global therapeutic limitation mean in communities with similar cultural background, even if there is a lower influence of life support withdrawal (8.2%) when compared to other countries regardless of their attitude towards the need to establish different degrees of control over technological resources applied to the critically ill. Further research should analyze the influence that moral perception of withdrawal as inconvenient in our society, has over our findings.

La muerte en un servicio de terapia intensiva: influencia de la abstencion y retiro del soporte vital / Death in an intensive care unit: influence of life support withholding and withdrawal

Se estudió la influencia de la abstención y retiro del soporte vital en la muerte ocurrida en un servicio de Terapia Intensiva durante un período de 32 meses. Sobre 2640 pacientes ingresados se registró la conducta terapéutica en 548 muertos, clasificando la misma en cinco categorías: (i) tratamiento completo, (ii) tratamiento completo con orden de no resucitación (ONR), (iii) abstención de soporte vital, (iv) retiro de soporte vital y (v) muerte cerebral. Hubo limitación terapéutica de soporte vital en el 45.6% (n= 250) con unpredominio importante de la abstención (ONR y abstención) en el 32.6% respecto del retiro de soporte vital (8.2%). Del estudio comparativo con otras estadísticas surge el hallazgo de un porcentaje global de limitación terapéutica media cercana a comunidades con una cultura similar, aunque con una incidencia de retiro (8.2%) manifiestamente inferior a la registrada en todos los países cualesquiera fuera su actitud frente a la necesidad de establecer diversos grados de control sobre el recurso tecnológico en el paciente crítico. Deberá indagarse la influencia que tiene la percepción moral del dejar de actuar, como un proceder inconveniente en nuestra sociedad, en los resultados observados.(AU)

The influence of life support withholding and withdrawal on the deaths which occurred in an Intensive Care Unit (ICU) over a period of 32 months was analysed. Of 2640 patients admitted in ICU, one of the following five mutually exclusive categories was registered on the 548 patients who died: (i) complete treatment; (ii) complete treatment with non-resuscitation order (NRO); (iii) withholding of life-sustaining treatment; (iv) withdrawal of life-sustaining treatment; and (v) brain death. There was therapeutic limitation of life support in 45.6% of cases (n=250), with an important majority of withholding (NRO and withholding) in 32.6% of cases, in comparison to withdrawal of life support (8.2% of cases). The comparative analysis with other statistic information suggests the existence of a similar global therapeutic limitation mean in communities with similar cultural background, even if there is a lower influence of life support withdrawal (8.2%) when compared to other countries regardless of their attitude towards the need to establish different degrees of control over technological resources applied to the critically ill. Further research should analyze the influence that moral perception of withdrawal as inconvenient in our society, has over our findings.(AU)

La muerte en un servicio de terapia intensiva: influencia de la abstencion y retiro del soporte vital / Death in an intensive care unit: influence of life support withholding and withdrawal

Se estudió la influencia de la abstención y retiro del soporte vital en la muerte ocurrida en un servicio de Terapia Intensiva durante un período de 32 meses. Sobre 2640 pacientes ingresados se registró la conducta terapéutica en 548 muertos, clasificando la misma en cinco categorías: (i) tratamiento completo, (ii) tratamiento completo con orden de no resucitación (ONR), (iii) abstención de soporte vital, (iv) retiro de soporte vital y (v) muerte cerebral. Hubo limitación terapéutica de soporte vital en el 45.6% (n= 250) con unpredominio importante de la abstención (ONR y abstención) en el 32.6% respecto del retiro de soporte vital (8.2%). Del estudio comparativo con otras estadísticas surge el hallazgo de un porcentaje global de limitación terapéutica media cercana a comunidades con una cultura similar, aunque con una incidencia de retiro (8.2%) manifiestamente inferior a la registrada en todos los países cualesquiera fuera su actitud frente a la necesidad de establecer diversos grados de control sobre el recurso tecnológico en el paciente crítico. Deberá indagarse la influencia que tiene la percepción moral del dejar de actuar, como un proceder inconveniente en nuestra sociedad, en los resultados observados.(AU)

The influence of life support withholding and withdrawal on the deaths which occurred in an Intensive Care Unit (ICU) over a period of 32 months was analysed. Of 2640 patients admitted in ICU, one of the following five mutually exclusive categories was registered on the 548 patients who died: (i) complete treatment; (ii) complete treatment with non-resuscitation order (NRO); (iii) withholding of life-sustaining treatment; (iv) withdrawal of life-sustaining treatment; and (v) brain death. There was therapeutic limitation of life support in 45.6% of cases (n=250), with an important majority of withholding (NRO and withholding) in 32.6% of cases, in comparison to withdrawal of life support (8.2% of cases). The comparative analysis with other statistic information suggests the existence of a similar global therapeutic limitation mean in communities with similar cultural background, even if there is a lower influence of life support withdrawal (8.2%) when compared to other countries regardless of their attitude towards the need to establish different degrees of control over technological resources applied to the critically ill. Further research should analyze the influence that moral perception of withdrawal as inconvenient in our society, has over our findings.(AU)

Cancer patients with septic shock: mortality predictors and neutropenia.

GOALS OF WORK: To study outcome and its predictive factors in cancer patients admitted to the ICU with septic shock, and the implications of neutropenia as a risk factor in this advanced stage of systemic inflammatory response. PATIENTS AND METHODS: A prospective consecutive observational cohort study was conducted in 73 adults with cancer and septic shock admitted to the ICU at the Cancer Medical Center associated with the University of Buenos Aires. MAIN RESULTS: The mortality rate from septic shock was 53.4% (95%CI 41.9 to 64.8%). The mean Acute Physiology and Chronic Health Evaluation (APACHE) II score on admission, the mean number of organ dysfunctions on admission or during the ICU stay, liver dysfunction, respiratory dysfunction, and the need for mechanical ventilation were predictive of mortality in a univariate analysis. Neutropenia was not associated with a worse prognosis in terms of mortality (56%) or mean days of ICU stay (6.64 days) in comparison with nonneutropenic patients (52.1% and 6.8 days) in the univariate analysis. In the logistic regression model only the need for mechanical ventilation and liver dysfunction remained independent predictors of mortality. CONCLUSIONS: Septic shock among cancer patients admitted to the ICU has a mortality rate similar to that reported for mixed populations, and it is particularly increased when hepatic or respiratory dysfunction develop. Neutropenia on admission does not seem to modify outcome.

[Acute respiratory distress syndrome. Role of steroids]. / Síndrome de distrés respiratorio agudo. Utilidad de los corticoides.

The acute respiratory distress syndrome (ARDS) represents 7.7% of the intensive care population, and is associated with great morbidity and mortality (58%). Frequently, the mortality can be attributed to more than one cause. Refractory hypoxemia is uncommon (15%) and most of the patients also have multiple organic dysfunction, sepsis or septic shock. Although there are many publications concerning series of cases and clinical trials using steroids as a part of the treatment of ARDS, this issue remains controversial. In this article the role of steroids in the ARDS is evaluated by analysis of the available literature. We conclude that steroids are useful in a subgroup of patients with unresolving ARDS, after ruling out an active infection or after treatment with antibiotics.