Characteristics and mortality of Mexican patients with COVID-19 and mechanical ventilation.

INTRODUCTION: COVID-19-associated mortality in patients who require mechanical ventilation is unknown in the Mexican population. OBJECTIVE: To describe the characteristics of Mexican patients with COVID-19 who required mechanical ventilation. METHODS: Observational cohort study carried out in an intensive care unit from March 25 to July 17, 2020. Data were obtained from a prospective database and electronic medical records, and were analyzed with the chi-square test, Fisher's exact test or Mann-Whitney's U-test. RESULTS: One hundred patients required mechanical ventilation; median age was 56 years, 31 % were females and 97 % were Latin American. Most common comorbidities were obesity (36 %), diabetes (26 %), hypertension (20 %), and chronic or end-stage kidney disease (10 %). At the end of the analysis, 11 patients remained in the ICU, 31 had been discharged alive and 58 (65.2 %) died; survivors were younger, had lower scores on severity and organ dysfunction scales, lower levels of C-reactive protein at ICU admission, were less likely to receive hemodialysis and vasopressors, and had longer hospital and ICU stays. CONCLUSIONS: This study adds information on the presentation and results of SARS-CoV-2-infected patients who require mechanical ventilation.

INTRODUCCIÓN: La mortalidad por COVID-19 en quienes requieren ventilación mecánica se desconoce en la población mexicana. OBJETIVO: Describir las características de pacientes mexicanos con COVID-19 que requirieron ventilación mecánica. MÉTODOS: Estudio de cohorte observacional en una unidad de terapia intensiva, del 25 de marzo al 17 de julio de 2020. Los datos se obtuvieron de una base de datos prospectiva y de registros clínicos electrónicos; fueron analizados con c2, prueba exacta de Fisher o prueba U de Mann-Whitney. RESULTADOS: Cien pacientes recibieron ventilación mecánica, la edad media fue de 56 años, 31 % era del sexo femenino y 97 %, latinoamericano. Las comorbilidades más comunes fueron obesidad (36 %), diabetes (26 %), hipertensión (20 %) y enfermedad renal crónica o renal terminal (10 %). Al término del análisis, 11 pacientes permanecían en la UCI, 31 egresaron vivos y 58 (65.2 %) fallecieron; los sobrevivientes fueron más jóvenes, con menores puntuación en las escalas de gravedad y disfunción orgánica, menores niveles de proteína C reactiva al ingreso a la UCI, menor propensión a hemodiálisis, necesidad de, necesidad de vasopresores y con mayor estancia hospitalaria y en la UCI. CONCLUSIONES: Este estudio agrega información sobre la presentación y resultados de pacientes con ventilación mecánica infectados con SARS-CoV-2.

Mechanical ventilator as a shared resource for the COVID-19 pandemic.

COVID-19, the causative agent of which is a new type of coronavirus called SARS-CoV-2, has caused the most severe pandemic in the last 100 years. The condition is mainly respiratory, and up to 5% of patients develop critical illness, a situation that has put enormous pressure on the health systems of affected countries. A high demand for care has mainly been observed in intensive care units and critical care resources, which is why the need to redistribute resources in critical medicine emerged, with an emphasis on distributive justice, which establishes the provision of care to the largest number of people and saving the largest number of lives. One principle lies in allocating resources to patients with higher life expectancy. Mechanical ventilator has been assumed to be an indivisible asset; however, simultaneous mechanical ventilation to more than one patient with COVID-19 is technically possible. Ventilator sharing is not without risks, but the principles of beneficence, non-maleficence and justice prevail. According to distributive justice, being a divisible resource, mechanical ventilator can be shared; however, we should ask ourselves if this action is ethically correct.

COVID-19, cuyo agente causal es un nuevo tipo de coronavirus denominado SARS-CoV-2, ha provocado la pandemia más grave en los últimos 100 años. La afección es principalmente respiratoria y hasta 5 % de los pacientes desarrolla enfermedad crítica, lo cual ha producido una enorme presión sobre los sistemas de salud de los países afectados. Principalmente se ha observado alta demanda de atención en las unidades de cuidados intensivos y de recursos de atención vital. De ahí la necesidad de redistribuir los recursos en medicina crítica, con énfasis en la justicia distributiva, la cual establece atender al mayor número de personas y salvar el mayor número de vidas. Un principio estriba en asignar los recursos a pacientes con mayores expectativas de vida. Se ha dado por hecho que el ventilador mecánico es un bien indivisible; sin embargo, técnicamente es posible la ventilación mecánica simultánea a más de un paciente con COVID-19. La acción de compartir el ventilador no está exenta de riesgos, pero prevalecen los principios de beneficencia, no maleficencia y justicia. Conforme la justicia distributiva, al ser un bien divisible, el ventilador mecánico puede ser compartido, sin embargo, cabe preguntarse si esta acción es éticamente correcta.

Association of independent risk factors with post-extubation failure in patients undergoing mechanical ventilation weaning.

INTRODUCTION: Even with an adequate mechanical ventilation weaning (MVW) protocol, the procedure fails in 15 to 30 % of cases. OBJECTIVE: To assess the association between independent risk factors (IRFs) and post-extubation failure in patients undergoing MVW in an intensive care unit. METHOD: Longitudinal, prospective, analytical cohort study in patients on mechanical ventilation for more than 24 hours and who were extubated. Pre-extubation reports of hemoglobin, albumin, phosphorus, waist-hip ratio and SOFA score were obtained. Extubation failure was defined as resumption of mechanical ventilation within 48 hours or less. RESULTS: 123 patients were extubated, out of whom 74 were males (60 %); average age was 50 ± 18 years. Extubation failure occurred in 37 (30 %). Hypoalbuminemia was associated as an independent risk factor in 29 (23.8 %, RR = 1.43, 95 % CI = 1.11-1.85) and hypophosphatemia was in 18 (14.6 %, RR = 2.98, 95 % CI = 1.66-5.35); two or more IRFs were observed in 22.7 % (RR = 1.51, 95 % CI = 1.14-2.00). CONCLUSIONS: Identifying independent risk factors prior to MVW can help reduce the risk of extubation failure and associated morbidity and mortality. INTRODUCCIÓN: Aun con adecuado protocolo de desconexión de la ventilación mecánica (DVM), el procedimiento falla en 15 a 30 % de los casos. OBJETIVO: Evaluar la asociación entre factores de riesgo independientes y fracaso posextubación en pacientes con DVM en una unidad de cuidados intensivos. MÉTODO: Estudio de cohorte, longitudinal, prospectivo, analítico, que incluyó pacientes sometidos a ventilación mecánica por más de 24 horas y que fueron extubados. Se obtuvieron reportes preextubación de hemoglobina, albúmina, fósforo, índice cintura-cadera y puntuación SOFA. Se definió como fracaso de extubación al reinicio de la ventilación mecánica en 48 horas o menos. RESULTADOS: Se extubaron 123 pacientes, 74 hombres (60 %); la edad promedio fue de 50 ± 18 años. Ocurrió fracaso de extubación en 37 (30 %). Como factores de riesgo independentes se asoció hipoalbuminemia en 29 (23.8 %, RR = 1.43, IC 95 % = 1.11-1.85) e hipofosfatemia en 18 (14.6 %, RR = 2.98, IC 95 % = 1.66-5.35); se observaron dos o más factores de riesgo independientes en 22.7 % (RR = 1.51, IC 95 % = 1.14-2.00). CONCLUSIONES: Identificar los factores de riesgo independentes antes de la DVM puede ayudar a reducir el fracaso de la extubación y la morbimortalidad asociada.

Simultaneous mechanical ventilation of several patients with a single ventilator.

INTRODUCTION: Simultaneous mechanical ventilation of several patients with a single ventilator might reduce the deficit of these devices for the care of patients with acute respiratory failure due to Covid-19. OBJECTIVE: To communicate the results of a mechanical ventilation exercise with a ventilator in a lung simulator, and simultaneously in two and four. RESULTS: No statistically significant differences were observed between programmed, recorded and measured positive end-expiratory pressure, mean airway pressure and peak pressure, except when simultaneously ventilating four lung simulators. CONCLUSIONS: Simultaneous mechanical ventilation should be implemented by medical personnel with experience in the procedure, be restricted to two patients and carried out in the intensive care unit.

INTRODUCCIÓN: La ventilación mecánica simultánea a varios pacientes con un solo ventilador podría disminuir el déficit de esos dispositivos para atender a los enfermos con insuficiencia respiratoria aguda por Covid-19. OBJETIVO: Comunicar los resultados de un ejercicio de ventilación mecánica con un ventilador en un simulador de pulmón, y simultáneamente en dos y cuatro. RESULTADOS: No se observaron diferencias estadísticamente significativas entre la presión positiva al final de la espiración, presión media de la vía aérea y presión pico programadas, registradas y medidas, excepto al ventilar simultáneamente cuatro simuladores de pulmón. CONCLUSIONES: La ventilación mecánica simultánea debe ser instaurada por personal médico con experiencia en el procedimiento, restringirse a dos pacientes y ser realizada en la unidad de cuidados intensivos.

At 50 years of the description of acute respiratory distress syndrome. / A 50 años de la descripción del síndrome de insuficiencia respiratoria aguda.

In 1967, Ashbaugh et al. published in the Lancet the description of a new entity, for which they coined the name "adult respiratory distress syndrome". On that article, they thoroughly described 12 patients who had respiratory distress with bilateral pulmonary infiltrates and oxygen therapy-refractory hypoxemia. For its management, emphasis was made on the importance of intubation and mechanical ventilation with positive end-expiratory pressure. At 50 years of its first publication, great advances on the knowledge of this condition have been achieved, which has influenced on patient management and survival. To celebrate this 50th anniversary, the National Academy of Medicine of Mexico organized a symposium with the purpose to spread the knowledge about this condition, recognize the researchers who made the original description and those who over the course of 50 years of history have contributed to its better understanding. The symposium addressed the topics of lung-kidney interaction, molecular bases of the disease and therapeutic advances.

En 1967, Ashbaugh et al. publicaron en Lancet la descripción de una nueva entidad para la que acuñaron el nombre "síndrome de distress respiratorio del adulto". En ese artículo describieron minuciosamente a 12 enfermos que presentaban insuficiencia respiratoria, con infiltración pulmonar bilateral e hipoxemia resistente a oxigenoterapia. Para su manejo se hizo énfasis en la importancia de la intubación y la ventilación mecánica con presión positiva al final de la espiración. A 50 años de la publicación se han logrado grandes avances en el conocimiento de esta enfermedad, lo que ha influido en el manejo y supervivencia de los pacientes. Para celebrar este cincuentenario, la Academia Nacional de Medicina de México organizó un simposio que tuvo como objetivos difundir el conocimiento de esta enfermedad, reconocer a los personajes que hicieron la descripción original y a quienes en 50 años de historia han contribuido a su mejor entendimiento. El simposio abordó los temas de interacción pulmón-riñón, bases moleculares de la enfermedad y avances en el tratamiento.

Quality of the aetiological diagnosis of ventilator-associated pneumonia in Spain in the opinion of intensive care specialists and microbiologists.

INTRODUCTION: Current guidelines for the microbiological diagnosis of ventilator-associated pneumonia (VAP) are imprecise. Based on data provided by intensive care specialists (ICS) and microbiologists, this study defines the clinical practices and microbiological techniques currently used for an aetiological diagnosis of VAP and pinpoints deficiencies. METHODS: Eighty hospitals in the national health network with intensive care and microbiology departments were sent two questionnaires, one for each department, in order to collect data on VAP diagnosis for the previous year. RESULTS: Out of the 80 hospitals, 35 (43.8%) hospitals participated. These included 673 ICU beds, 32,020 ICU admissions, 173,820 ICU days stay, and generated 27,048 lower respiratory tract specimens in the year. A third of the hospitals (35%) had a microbiology department available 24/7. Most samples (83%) were tracheal aspirates. Gram stain results were immediately reported in around half (47%) of the hospitals. Quantification was made in 75% of hospitals. Molecular techniques and direct susceptibility testing were performed in 12% and one institution, respectively. Mean turnaround time for a microbiological report was 1.7 (SD; 0.7), and 2.2 (SD; 0.6) days for a negative and positive result, respectively. Telephone/in-person information was offered by 65% of the hospitals. Most (89%) ICS considered microbiological information as very useful. No written procedures were available in half the ICUs. CONCLUSIONS: Both ICS and microbiologists agreed that present guidelines for the diagnosis of VAP could be much improved, and that a new set of consensus guidelines is urgently required. A need for guidelines to be more effectively implemented was also identified in order to improve outcomes in patients with VAP.

Nursing workload and adherence to non-pharmacological measures in the prevention of ventilator-associated pneumonia. A pilot study. / Carga de trabajo y cumplimiento por parte de las enfermeras de las medidas no farmacológicas para la prevención de la neumonía asociada a la ventilación mecánica. Estudio piloto.

OBJECTIVE: To analyse whether adherence to non-pharmacological measures in the prevention of ventilator-associated pneumonia (VAP) is associated with nursing workload. METHODS: A prospective observational study performed in a single medical-surgical ICU. Nurses in charge of patients under ventilator support were assessed. VARIABLES: knowledge questionnaire, application of non-pharmacological VAP prevention measures, and workload (Nine Equivalents of Nursing Manpower Use Score). Phases: 1) the nurses carried out a educational programme, consisting of 60-minute lectures on non-pharmacological measures for VAP prevention, and at the end completed a questionnaire knowledge; 2) observation period; 3) knowledge questionnaire. RESULTS: Among 67 ICU-staff nurses, 54 completed the educational programme and were observed. A total of 160 observations of 49 nurses were made. Adequate knowledge was confirmed in both the initial and final questionnaires. Application of preventive measures ranged from 11% for hand washing pre-aspiration to 97% for the use of a sterile aspiration probe. The Nine Equivalents of Nursing Manpower Use Score was 50±13. No significant differences were observed between the association of the nurses' knowledge and the application of preventive measures or between workload and the application of preventive measures. CONCLUSIONS: Nurses' knowledge of VAP prevention measures is not necessarily applied in daily practice. Failure to follow these measures is not subject to lack of knowledge or to increased workload, but presumably to contextual factors.

Time of elevation of head of bed for patients receiving mechanical ventilation and its related factors. / Tiempo de elevación del cabezal de la cama del paciente con ventilación mecánica y factores relacionados.

INTRODUCTION: The semirecumbent position is a widespread recommendation for the prevention of pneumonia associated with mechanical ventilation. AIMS: To identify the time of elevation of head of bed for patients under mechanical ventilation and the factors related to such elevation in an intensive care unit. MATERIALS AND METHODS: An observational, descriptive cross-sectional study. Conducted in an intensive care unit of a tertiary hospital from April to June 2015. The studied population were mechanically ventilated patients. Daily hours in which patients remained with the head of the bed elevated (≥30°), socio-demographic data and clinical variables were recorded. RESULTS: 261 head elevation measurements were collected. The average daily hours that patients remained at ≥30° was 16h28' (SD ±5h38'), equivalent to 68.6% (SD ±23.5%) of the day. Factors related to elevations ≥30° for longer were: enteral nutrition, levels of deep sedation, cardiac and neurocritical diagnostics. Factors that hindered the position were: sedation levels for agitation and abdominal pathologies. Sex, age and ventilation mode did not show a significant relationship with bed head elevation. CONCLUSIONS: Although raising the head of the bed is an easy to perform, economical and measurable preventive measure, its compliance is low due to specific factors specific related o the patient's clinical condition. Using innovations such as continuous measurement of the head position helps to evaluate clinical practice and allows to carry out improvement actions whose impact is beneficial to the patient.

Enteral nutrition volume is not correlated with lower respiratory tract infection in patients on mechanical ventilation.

OBJECTIVE: To evaluate the effect of enteral nutrition volume, gastrointestinal function and the type of acid suppressive drug upon the incidence of lower respiratory tract infections in critically ill patients on mechanical ventilation (MV). DESIGN: A retrospective secondary analysis was carried out. SETTING: The Intensive Care Unit of a University Hospital. PATIENTS OR PARTICIPANTS: Patients≥18-years-old expected to need MV for more than four days, and receiving enteral nutrition by nasogastric tube within 24h of starting MV. INTERVENTIONS: We correlated enteral nutrition volume administered during the first 10 days, gastrointestinal function and the type of acid suppressive therapy with the episodes of lower respiratory tract infection up until day 28. Cox proportional hazards ratios in univariate and adjusted multivariate models were used. Statistical significance was considered for p<0.05. MAIN VARIABLES OF INTEREST: Lower respiratory tract infection episodes. RESULTS: Sixty-six out of 185 patients (35.7%) had infection; 27 patients had ventilator-associated pneumonia; and 39 presented ventilator-associated tracheobronchitis. Uninfected and infected groups were similar in terms of enteral nutrition volume (54±12 and 54±9mL/h; p=0.94) and caloric intake (19.4±4.9 and 19.6±5.2kcal/kg/d; p=0.81). The Cox proportional hazards model showed neurological indication of MV to be the only independent variable related to infection (p=0.001). Enteral nutrition volume, the type of acid suppressive therapy, and the use of prokinetic agents were not significantly correlated to infection. CONCLUSIONS: Enteral nutrition volume and caloric intake, gastrointestinal dysfunction and the type of acid suppressive therapy used were not associated to lower respiratory tract infection in patients on MV.

Update on traumatic acute spinal cord injury. Part 2. / Actualización en lesión medular aguda postraumática. Parte 2.

The aim of treatment in acute traumatic spinal cord injury is to preserve residual neurologic function, avoid secondary injury, and restore spinal alignment and stability. In this second part of the review, we describe the management of spinal cord injury focusing on issues related to short-term respiratory management, where the preservation of diaphragmatic function is a priority, with prediction of the duration of mechanical ventilation and the need for tracheostomy. Surgical assessment of spinal injuries based on updated criteria is discussed, taking into account that although the type of intervention depends on the surgical team, nowadays treatment should afford early spinal decompression and stabilization. Within a comprehensive strategy in spinal cord injury, it is essential to identify and properly treat patient anxiety and pain associated to spinal cord injury, as well as to prevent and ensure the early diagnosis of complications secondary to spinal cord injury (thromboembolic disease, gastrointestinal and urinary disorders, pressure ulcers).

Mechanical ventilation in acute respiratory distress syndrome: The open lung revisited.

Acute respiratory distress syndrome (ARDS) is still related to high mortality and morbidity rates. Most patients with ARDS will require ventilatory support. This treatment has a direct impact upon patient outcome and is associated to major side effects. In this regard, ventilator-associated lung injury (VALI) is the main concern when this technique is used. The ultimate mechanisms of VALI and its management are under constant evolution. The present review describes the classical mechanisms of VALI and how they have evolved with recent findings from physiopathological and clinical studies, with the aim of analyzing the clinical implications derived from them. Lastly, a series of knowledge-based recommendations are proposed that can be helpful for the ventilator assisted management of ARDS at the patient bedside.

Mechanical ventilation in patients subjected to extracorporeal membrane oxygenation (ECMO). / Ventilación mecánica en pacientes tratados con membrana de oxigenación extracorpórea (ECMO).

Mechanical ventilation (MV) is a crucial element in the management of acute respiratory distress syndrome (ARDS), because there is high level evidence that a low tidal volume of 6ml/kg (protective ventilation) improves survival. In these patients with refractory respiratory insufficiency, venovenous extracorporeal membrane oxygenation (ECMO) can be used. This salvage technique improves oxygenation, promotes CO2 clearance, and facilitates protective and ultraprotective MV, potentially minimizing ventilation-induced lung injury. Although numerous trials have investigated different ventilation strategies in patients with ARDS, consensus is lacking on the optimal MV settings during venovenous ECMO. Although the concept of "lung rest" was introduced years ago, there are no evidence-based guidelines on its use in application to MV in patients supported by ECMO. How MV in ECMO patients can promote lung recovery and weaning from ventilation is not clear. The purpose of this review is to describe the ventilation strategies used during venovenous ECMO in clinical practice.

Compliance-guided versus FiO2-driven positive-end expiratory pressure in patients with moderate or severe acute respiratory distress syndrome according to the Berlin definition.

OBJECTIVE: To study the effect of setting positive end-expiratory pressure (PEEP) in an individualized manner (based on highest static compliance) compared to setting PEEP according to FiO2 upon mortality at 28 and 90 days, in patients with different severity acute respiratory distress syndrome (ARDS). SETTING: A Spanish medical-surgical ICU. DESIGN: A post hoc analysis of a randomized controlled pilot study. PATIENTS: Patients with ARDS. INTERVENTIONS: Ventilation with low tidal volumes and pressure limitation at 30cmH2O, randomized in two groups according to the method used to set PEEP: FiO2-guided PEEP group according to FiO2 applied and compliance-guided group according to the highest compliance. PRIMARY VARIABLES OF INTEREST: Demographic data, risk factors and severity of ARDS, APACHE II and SOFA scores, daily Lung Injury Score, ventilatory measurements, ICU and hospital stay, organ failure and mortality at day 28 and 90 after inclusion. RESULTS: A total of 159 patients with ARDS were evaluated, but just 70 patients were included. Severe ARDS patients showed more organ dysfunction-free days at 28 days (12.83±10.70 versus 3.09±7.23; p=0.04) and at 90 days (6.73±22.31 vs. 54.17±42.14, p=0.03), and a trend toward lower 90-days mortality (33.3% vs. 90.9%, p=0.02), when PEEP was applied according to the best static compliance. Patients with moderate ARDS did not show these effects. CONCLUSIONS: In patients with severe ARDS, individualized PEEP selection based on the best static compliance was associated to lower mortality at 90 days, with an increase in organ dysfunction-free days at 28 and 90 days.

Preemptive hemodynamic intervention restricting the administration of fluids attenuates lung edema progression in oleic acid-induced lung injury.

OBJECTIVE: A study is made of the influence of preemptive hemodynamic intervention restricting fluid administration upon the development of oleic acid-induced lung injury. DESIGN: A randomized in vivo study in rabbits was carried out. SETTING: University research laboratory. SUBJECTS: Sixteen anesthetized, mechanically ventilated rabbits. VARIABLES: Hemodynamic measurements obtained by transesophageal Doppler signal. Respiratory mechanics computed by a least square fitting method. Lung edema assessed by the ratio of wet weight to dry weight of the right lung. Histological examination of the left lung. INTERVENTIONS: Animals were randomly assigned to either the early protective lung strategy (EPLS) (n=8) or the early protective hemodynamic strategy (EPHS) (n=8). In both groups, lung injury was induced by the intravenous infusion of oleic acid (OA) (0.133mlkg-1h-1 for 2h). At the same time, the EPLS group received 15mlkg-1h-1 of Ringer lactate solution, while the EPHS group received 30mlkg-1h-1. Measurements were obtained at baseline and 1 and 2h after starting OA infusion. RESULTS: After 2h, the cardiac index decreased in the EPLS group (p<0.05), whereas in the EPHS group it remained unchanged. Lung compliance decreased significantly only in the EPHS group (p<0.05). Lung edema was greater in the EPHS group (p<0.05). Histological damage proved similar in both groups (p=0.4). CONCLUSIONS: In this experimental model of early lung injury, lung edema progression was attenuated by preemptively restricting the administration of fluids.

Effect of FiO2 in the measurement of VO2 and VCO2 using the E-COXV metabolic monitor. / Efecto de la FiO2 sobre la medición del VO2 y la VCO2 con el monitor metabólico E-COVX.

OBJECTIVE: We evaluated the effect of changes in FiO2 on the bias and accuracy of the determination of oxygen consumption (V˙O2) and carbon dioxide production (V˙CO2) using the E-COVX monitor in patients with mechanical ventilation. DESIGN: Descriptive of concordance. SETTING: Intensive Care Unit. PATIENTS OR PARTICIPANTS: Patients with mechanical ventilation. INTERVENTIONS: We measured V˙O2 and V˙CO2 using the E-COVX monitor. Values recorded were the average in 5min. Two groups of 30 patients. We analyzed: 1) the reproducibility in the measurement of V˙O2 and V˙CO2 at FiO2 0.4, and 2) the effect of the changes in FiO2 on the measurement of V˙O2 and V˙CO2. Statistical analysis was performed using Bland and Altman test. VARIABLES OF MAIN INTEREST: Bias and accuracy. RESULTS: 1) FiO2 0.4 reproducibility: The bias in the measurement of V˙O2 and V˙CO2 was 1.6 and 2.1mL/min, respectively, and accuracy was 9.7 to -8.3% and 7.2 to -5.2%, respectively, and 2) effect of FiO2 on V˙O2: The bias of V˙O2 measured at FiO2 0.4 and 0.6 was -4.0mL/min and FiO2 0.4 and 0.8 was 5.2mL/min. Accuracy between FiO2 0.4 and 0.6 was 11.9 to -14.1%, and between FiO2 0.4 and 0.8 was 43.9 to -39.7%. CONCLUSIONS: The E-COVX monitor evaluates V˙O2 and V˙CO2 in critical patients with mechanical ventilation with a clinically acceptable accuracy until FiO2 0.6.

Organ donor management: Eight common recommendations and actions that deserve reflection.

Despite major advances in our understanding of the physiopathology of brain death (BD), there are important controversies as to which protocol is the most appropriate for organ donor management. Many recent reviews on this subject offer recommendations that are sometimes contradictory and in some cases are not applied to other critically ill patients. This article offers a review of the publications (many of them recent) with an impact upon these controversial measures and which can help to confirm, refute or open new areas of research into the most appropriate measures for the management of organ donors in BD, and which should contribute to discard certain established recommendations based on preconceived ideas, that lead to actions lacking a physiopathological basis. Aspects such as catecholamine storm management, use of vasoactive drugs, hemodynamic objectives and monitoring, assessment of the heart for donation, and general care of the donor in BD are reviewed.

[A first step towards safer sedation and analgesia: A systematic evaluation of outcomes and level of sedation and analgesia in the mechanically ventilated critically ill patient]. / Un primer paso hacia una analgosedación más segura: evaluación sistemática de objetivos y grado de analgesia y sedación en el paciente crítico con ventilación mecánica.

INTRODUCTION: Safe analgesia and sedation strategies are necessary in order to avoid under or over sedation, as well as improving the comfort and safety of critical care patients. OBJECTIVES: To compare and contrast a multidisciplinary protocol of systematic evaluation and management of analgesia and sedation in a group of critical care patients on mechanical ventilation with the usual procedures. MATERIALS AND METHODS: A cohort study with contemporary series was conducted in a tertiary care medical-surgical ICU February to November during 2013 and 2014. The inclusion criteria were mechanical ventilation ≥ 24h and use of sedation by continuous infusion. Sedation was monitored using the Richmond agitation-sedation scale or bispectral index, and analgesia were measured using the numeric rating scale, or behavioural indicators of pain scale. The study variables included; mechanical ventilation time, weaning time, ventilation support time, artificial airway time, continuous sedative infusion time, daily dose and frequency of analgesic and sedative drug use, hospital stay, and ICU and hospital mortality, Richmond agitation-sedation scale, bispectral index, numeric rating scale, and behavioural indicators of pain scale measurements. Kruskal Wallis and Chi2, and a significance of p<.05 were used. RESULTS: The study included 153 admissions, 75 pre-intervention and 78 post-intervention, with a mean age of 55.7±13 years old, and 67% men. Both groups showed similarities in age, reason for admission, and APACHE. There were non-significant decreases in mechanical ventilation time 4 (1.4-9.2) and 3.2 (1.4-8.1) days, respectively; p= 0.7, continuous sedative infusion time 6 (3-11) and 5 (3-11) days; p= 0.9, length of hospital stay 29 (18-52); 25 (14-41) days; p= 0.1, ICU mortality (8 vs. 5%; p= 0.4), and hospital mortality (10.6 vs. 9.4%: p= 0.8). Daily doses of midazolam and remifentanil decreased 347 (227-479) mg/day; 261 (159-358) mg/day; p= 0.02 and 2175 (1427-3285) mcg/day; 1500 (715-2740) mcg/day; p= 0.02, respectively. There were increases in the use of remifentanil (32% vs. 51%; p= 0.01), dexmedetomidine (0 vs.6%; p= 0.02), dexketoprofen (60 vs. 76%; p= 0.03), and haloperidol (15 vs.28%; p= 0.04). The use of morphine decreased (71 vs. 54%; p= 0.03). There was an increase in the number of measurements and Richmond agitation-sedation scale scores 6 (3-17); 21 (9-39); p< 0.0001, behavioural indicators of pain scale 6 (3-18); 19(8-33); p< 0.001 and numeric rating scale 4 (2-6); 8 (6-17); p< 0.0001. CONCLUSIONS: The implementation of a multidisciplinary protocol of systematic evaluation of analgesia and sedation management achieved an improvement in monitoring and adequacy of dose to patient needs, leading to improved outcomes.

Psychometric validation of the behavioral indicators of pain scale for the assessment of pain in mechanically ventilated and unable to self-report critical care patients.

OBJECTIVE: To assess the psychometric properties of the behavioral indicators of pain scale (ESCID) when applied to a wide range of medical and surgical critical patients. DESIGN: A multicentre, prospective observational study was designed to validate a scale measuring instrument. SETTING: Twenty Intensive Care Units of 14 hospitals belonging to the Spanish National Health System. PARTICIPANTS: A total of 286 mechanically ventilated, unable to self-report critically ill medical and surgical adult patients. PROCEDURE: Pain levels were measured by two independent evaluators simultaneously, using two scales: ESCID and the behavioral pain scale (BPS). Pain was observed before, during, and after two painful procedures (turning, tracheal suctioning) and one non-painful procedure. MAIN VARIABLES: ESCID reliability was measured on the basis of internal consistency using the Cronbach-α coefficient. Inter-rater and intra-rater agreement were measured. The Spearman correlation coefficient was used to assess the correlation between ESCID and BPS. RESULTS: A total of 4386 observations were made in 286 patients (62% medical and 38% surgical). High correlation was found between ESCID and BPS (r=0.94-0.99; p<0.001), together with high intra-rater and inter-rater concordance. ESCID was internally reliable, with a Cronbach-α value of 0.85 (95%CI 0.81-0.88). Cronbach-α coefficients for ESCID domains were high: facial expression 0.87 (95%CI 0.84-0.89), calmness 0.84 (95%CI 0.81-0.87), muscle tone 0.80 (95%CI 0.75-0.84), compliance with mechanical ventilation 0.70 (95%CI 0.63-0.75) and consolability 0.85 (95%CI 0.81-0.88). CONCLUSION: ESCID is valid and reliable for measuring pain in mechanically ventilated unable to self-report medical and surgical critical care patients. CLINICALTRIALS.GOV: NCT01744717.

Diastolic dysfunction in the critically ill patient.

Left ventricular diastolic dysfunction is a common finding in critically ill patients. It is characterized by a progressive deterioration of the relaxation and the compliance of the left ventricle. Two-dimensional and Doppler echocardiography is a cornerstone in its diagnosis. Acute pulmonary edema associated with hypertensive crisis is the most frequent presentation of diastolic dysfunction critically ill patients. Myocardial ischemia, sepsis and weaning failure from mechanical ventilation also may be associated with diastolic dysfunction. The treatment is based on the reduction of pulmonary congestion and left ventricular filling pressures. Some studies have found a prognostic role of diastolic dysfunction in some diseases such as sepsis. The present review aims to analyze thoroughly the echocardiographic diagnosis and the most frequent scenarios in critically ill patients in whom diastolic dysfunction plays a key role.

Effectiveness and predictors of failure of noninvasive mechanical ventilation in acute respiratory failure.

OBJECTIVE: To assess the effectiveness and identify predictors of failure of noninvasive ventilation. DESIGN: A retrospective, longitudinal descriptive study was made. SETTING: Adult patients with acute respiratory failure. PATIENTS: A total of 410 consecutive patients with noninvasive ventilation treated in an Intensive Care Unit of a tertiary university hospital from 2006 to 2011. PROCEDURES: Noninvasive ventilation. MAIN VARIABLES OF INTEREST: Demographic variables and clinical and laboratory test parameters at the start and two hours after the start of noninvasive ventilation. Evolution during admission to the Unit and until hospital discharge. RESULTS: The failure rate was 50%, with an overall mortality rate of 33%. A total of 156 patients had hypoxemic respiratory failure, 87 postextubation respiratory failure, 78 exacerbation of chronic obstructive pulmonary disease, 61 hypercapnic respiratory failure without chronic obstructive pulmonary disease, and 28 had acute pulmonary edema. The failure rates were 74%, 54%, 27%, 31% and 21%, respectively. The etiology of respiratory failure, serum bilirubin at the start, APACHEII score, radiological findings, the need for sedation to tolerate noninvasive ventilation, changes in level of consciousness, PaO2/FIO2 ratio, respiratory rate and heart rate from the start and two hours after the start of noninvasive ventilation were independently associated to failure. CONCLUSIONS: The effectiveness of noninvasive ventilation varies according to the etiology of respiratory failure. Its use in hypoxemic respiratory failure and postextubation respiratory failure should be assessed individually. Predictors of failure could be useful to prevent delayed intubation.