Medidas de contingencia en un servicio de neumonología intervencionista para la realización de procedimientos de broncoscopía rígida durante la pandemia de COVID-19 / Contingency Measures in an Interventional Pulmonology Service for Rigid Bronchoscopy Procedures during the COVID-19 Pandemic

El día 30 de enero de 2020 la Organización Mundial de la Salud (OMS) reconoce la condición de pandemia por el virus SARS-CoV2 responsable de la enfermedad por coronavirus de 2019 (COVID-CoV2 por su denominación en inglés). Se ha demostrado que la vía respiratoria de pacientes infectados por COVID-19 tiene una alta carga viral, especialmente en nariz, garganta y tráquea. Los procedimientos que involucran el tracto aerodigestivo superior, como la broncoscopía, se consideran de alto riesgo de infección. Recomendaciones de diferentes sociedades establecen lineamientos para la realización de estos procedimientos, recomendando medidas de seguridad específicas evitando en lo posible la realización de broncoscopía rígida. Nuestra unidad corresponde a un servicio de neumonología intervencionista del sistema de salud público. Para hacer frente a la demanda de atención, necesidad de realizar procedimientos impostergables y una limitación en infraestructura y recursos, se inició un plan de contingencia y prueba de elementos alternativos orientados a potenciar la seguridad del personal y sus pacientes. Se presentan en este trabajo las medidas generales y nuevos dispositivos incluidos en nuestra secuencia de trabajo con el fin de mejorar la bioseguridad para el personal de salud y el paciente ante la necesidad de continuar realizando procedimientos.

On January 30, 2020, the World Health Organization (WHO) declares the pandemic of SARS-CoV2, responsible for the coronavirus disease of 2019 (COVID-CoV2). It has been shown that the airways of patients infected with COVID-19 have a high viral load, especially in the nose, throat and trachea. Procedures involving the upper aerodigestive tract, such as the bronchoscopy, are considered to carry a high risk of infection. Recommendations from different societies establish certain guidelines for these procedures, suggesting specific safety measures and, where possible, avoiding the performance of rigid bronchospies. Our unit belongs to an interventional pulmonology service of the Public Health System. In order to be able to meet the demand for medical care, the need to perform urgent procedures and the limitation to infrastructure and resources, we began a contingency plan and testing of alternative elements intended to increase the safety of the staff and the patients. This study introduces general measures and new devices included in our work sequence with the purpose of improving biosafety for the health staff and the patient when there is still a need to follow the procedures.

Bilateral lung disease, extensive and diffuse. Diagnosis of pulmonary alveolar proteinosis by bronchoscopic cryobiopsy.

Pulmonary alveolar proteinosis (PAP) is a rare disease characterized by the intra-alveolar accumulation of a proteinaceous phospholipid-laden material called surfactant. Clinically, this disease should be suspected with respiratory failure in association with a crazy paving pattern on high-resolution chest computed tomography. We report a 24-year-old gentleman who was referred to us for a history of respiratory failure, treatment with invasive ventilation and tracheostomy. His blood exams and biochemistry were normal. His infectious and rheumatological panel was negative for a secondary disease. A flexible bronchoscopy with a transbronchial biopsy through a CryoProbe was performed. An anatomopathological analysis was periodic acid-Schiff positive for PAP. A CryoProbe is a recently developed diagnostic tool that improves the diagnostic yield in diffuse lung diseases compared to bronchoscopy with transbronchial biopsy. This method should be considered for patients with diffuse lung disease and PAP.

Severe hypercapnia and outcome of mechanically ventilated patients with moderate or severe acute respiratory distress syndrome.

PURPOSE: To analyze the relationship between hypercapnia developing within the first 48 h after the start of mechanical ventilation and outcome in patients with acute respiratory distress syndrome (ARDS). PATIENTS AND METHODS: We performed a secondary analysis of three prospective non-interventional cohort studies focusing on ARDS patients from 927 intensive care units (ICUs) in 40 countries. These patients received mechanical ventilation for more than 12 h during 1-month periods in 1998, 2004, and 2010. We used multivariable logistic regression and a propensity score analysis to examine the association between hypercapnia and ICU mortality. MAIN OUTCOMES: We included 1899 patients with ARDS in this study. The relationship between maximum PaCO2 in the first 48 h and mortality suggests higher mortality at or above PaCO2 of ≥50 mmHg. Patients with severe hypercapnia (PaCO2 ≥50 mmHg) had higher complication rates, more organ failures, and worse outcomes. After adjusting for age, SAPS II score, respiratory rate, positive end-expiratory pressure, PaO2/FiO2 ratio, driving pressure, pressure/volume limitation strategy (PLS), corrected minute ventilation, and presence of acidosis, severe hypercapnia was associated with increased risk of ICU mortality [odds ratio (OR) 1.93, 95% confidence interval (CI) 1.32 to 2.81; p = 0.001]. In patients with severe hypercapnia matched for all other variables, ventilation with PLS was associated with higher ICU mortality (OR 1.58, CI 95% 1.04-2.41; p = 0.032). CONCLUSIONS: Severe hypercapnia appears to be independently associated with higher ICU mortality in patients with ARDS. TRIAL REGISTRATION: Clinicaltrials.gov identifier, NCT01093482.

Association between ventilatory settings and development of acute respiratory distress syndrome in mechanically ventilated patients due to brain injury.

PURPOSE: In neurologically critically ill patients with mechanical ventilation (MV), the development of acute respiratory distress syndrome (ARDS) is a major contributor to morbidity and mortality, but the role of ventilatory management has been scarcely evaluated. We evaluate the association of tidal volume, level of PEEP and driving pressure with the development of ARDS in a population of patients with brain injury. MATERIALS AND METHODS: We performed a secondary analysis of a prospective, observational study on mechanical ventilation. RESULTS: We included 986 patients mechanically ventilated due to an acute brain injury (hemorrhagic stroke, ischemic stroke or brain trauma). Incidence of ARDS in this cohort was 3%. Multivariate analysis suggested that driving pressure could be associated with the development of ARDS (odds ratio for unit increment of driving pressure 1.12; confidence interval for 95%: 1.01 to 1.23) whereas we did not observe association for tidal volume (in ml per kg of predicted body weight) or level of PEEP. ARDS was associated with an increase in mortality, longer duration of mechanical ventilation, and longer ICU length of stay. CONCLUSIONS: In a cohort of brain-injured patients the development of ARDS was not common. Driving pressure was associated with the development of this disease.

Nuevos procedimientos broncoscópicos en Argentina: Reducción volumétrica pulmonar endoscópica con válvulas endobronquiales / Bronchoscopic lung volume reduction. New bronchoscopic procedures in Argentina

La Enfermedad Pulmonar Obstructiva Crónica (EPOC) es una enfermedad caracterizada por limitación del flujo aéreo espiratorio donde el atrapamiento aéreo y la hiperinsuflación dinámica conducen a la producción de disnea que muchas veces incapacita al paciente a pesar de un correcto tratamiento farmacológico y de rehabilitación. Los tratamientos quirúrgicos destinados a paliar esta situación como la cirugía de reducción de volumen pulmonar (CRVP) presentan una morbimortalidad que limita su uso. La búsqueda de formas menos invasivas para conseguir el mismo propósito dieron origen a una serie de procedimientos broncoscópicos para la reducción de volumen pulmonar dentro de los cuales, las válvulas endobronquiales (VEB), son las que acumulan mayor desarrollo y experiencia. Si bien los estudios con VEB son heterogéneos y en su conjunto, muestran modestos beneficios en los test de función pulmonar, ejercicio y calidad de vida relacionada con la salud, existe un grupo de pacientes con enfisema pulmonar heterogéneo, cisura interlobar intacta, atrapamiento aéreo severo y baja tolerancia al ejercicio que muestra beneficios estadística y clínicamente significativos. Nuevos estudios se encuentran en desarrollo para dar más peso de evidencia a la acumulada en la actualidad.

Chronic Obstructive Pulmonary Disease (COPD) is characterized by airflow limitation, air trapping and dynamic hyperinflation that lead to disabling dyspnea despite appropriate pharmacologic treatment and pulmonary rehabilitation. Though surgical treatments such as lung transplant surgery and lung volume reduction (LVRS) are available, their high morbidity and mortality limit their use. To avoid these complications multiple procedures for bronchoscopic lung volume reduction have been developed, among which endobronchial valves (EBV) have accumulated the largest amount of evidence. While studies with EBV are heterogeneous and show modest benefits in pulmonary function tests, exercise capacity and quality of life, there is a group of patients with heterogeneous emphysema, intact interlobar fissure, severe air trapping and low exercise tolerance that show a statistically and clinically significant benefits. New studies are under way to further support the growing evidence.

Management and outcome of mechanically ventilated patients after cardiac arrest.

INTRODUCTION: The aim of this study was to describe and compare the changes in ventilator management and complications over time, as well as variables associated with 28-day hospital mortality in patients receiving mechanical ventilation (MV) after cardiac arrest. METHODS: We performed a secondary analysis of three prospective, observational multicenter studies conducted in 1998, 2004 and 2010 in 927 ICUs from 40 countries. We screened 18,302 patients receiving MV for more than 12 hours during a one-month-period. We included 812 patients receiving MV after cardiac arrest. We collected data on demographics, daily ventilator settings, complications during ventilation and outcomes. Multivariate logistic regression analysis was performed to calculate odds ratios, determining which variables within 24 hours of hospital admission were associated with 28-day hospital mortality and occurrence of acute respiratory distress syndrome (ARDS) and pneumonia acquired during ICU stay at 48 hours after admission. RESULTS: Among 812 patients, 100 were included from 1998, 239 from 2004 and 473 from 2010. Ventilatory management changed over time, with decreased tidal volumes (VT) (1998: mean 8.9 (standard deviation (SD) 2) ml/kg actual body weight (ABW), 2010: 6.7 (SD 2) ml/kg ABW; 2004: 9 (SD 2.3) ml/kg predicted body weight (PBW), 2010: 7.95 (SD 1.7) ml/kg PBW) and increased positive end-expiratory pressure (PEEP) (1998: mean 3.5 (SD 3), 2010: 6.5 (SD 3); P <0.001). Patients included from 2010 had more sepsis, cardiovascular dysfunction and neurological failure, but 28-day hospital mortality was similar over time (52% in 1998, 57% in 2004 and 52% in 2010). Variables independently associated with 28-day hospital mortality were: older age, PaO2 <60 mmHg, cardiovascular dysfunction and less use of sedative agents. Higher VT, and plateau pressure with lower PEEP were associated with occurrence of ARDS and pneumonia acquired during ICU stay. CONCLUSIONS: Protective mechanical ventilation with lower VT and higher PEEP is more commonly used after cardiac arrest. The incidence of pulmonary complications decreased, while other non-respiratory organ failures increased with time. The application of protective mechanical ventilation and the prevention of single and multiple organ failure may be considered to improve outcome in patients after cardiac arrest.

Impact of sedation and analgesia during noninvasive positive pressure ventilation on outcome: a marginal structural model causal analysis.

PURPOSE: There are limited data available about the role of sedation and analgesia during noninvasive positive pressure ventilation (NPPV). The objective of study was to estimate the effect of analgesic or sedative drugs on the failure of NPPV. METHODS: We studied patients who received at least 2 h of NPPV as first-line therapy in a prospective observational study carried out in 322 intensive care units from 30 countries. A marginal structural model (MSM) was used to analyze the association between the use of analgesic or sedative drugs and NPPV failure (defined as need for invasive mechanical ventilation). RESULTS: 842 patients were included in the analysis. Of these, 165 patients (19.6%) received analgesic or sedative drugs at some time during NPPV; 33 of them received both. In the adjusted analysis, the use of analgesics (odds ratio 1.8, 95% confidence interval 0.6-5.4) or sedatives (odds ratio 2.8, 95% CI 0.85-9.4) alone was not associated with NPPV failure, but their combined use was associated with failure (odds ratio 5.7, 95% CI 1.8-18.4). CONCLUSIONS: Slightly less than 20% of patients received analgesic or sedative drugs during NPPV, with no apparent effect on outcome when used alone. However, the simultaneous use of analgesics and sedatives may be associated with failure of NPPV.

Evolution of mortality over time in patients receiving mechanical ventilation.

RATIONALE: Baseline characteristics and management have changed over time in patients requiring mechanical ventilation; however, the impact of these changes on patient outcomes is unclear. OBJECTIVES: To estimate whether mortality in mechanically ventilated patients has changed over time. METHODS: Prospective cohort studies conducted in 1998, 2004, and 2010, including patients receiving mechanical ventilation for more than 12 hours in a 1-month period, from 927 units in 40 countries. To examine effects over time on mortality in intensive care units, we performed generalized estimating equation models. MEASUREMENTS AND MAIN RESULTS: We included 18,302 patients. The reasons for initiating mechanical ventilation varied significantly among cohorts. Ventilatory management changed over time (P < 0.001), with increased use of noninvasive positive-pressure ventilation (5% in 1998 to 14% in 2010), a decrease in tidal volume (mean 8.8 ml/kg actual body weight [SD = 2.1] in 1998 to 6.9 ml/kg [SD = 1.9] in 2010), and an increase in applied positive end-expiratory pressure (mean 4.2 cm H2O [SD = 3.8] in 1998 to 7.0 cm of H2O [SD = 3.0] in 2010). Crude mortality in the intensive care unit decreased in 2010 compared with 1998 (28 versus 31%; odds ratio, 0.87; 95% confidence interval, 0.80-0.94), despite a similar complication rate. Hospital mortality decreased similarly. After adjusting for baseline and management variables, this difference remained significant (odds ratio, 0.78; 95% confidence interval, 0.67-0.92). CONCLUSIONS: Patient characteristics and ventilation practices have changed over time, and outcomes of mechanically ventilated patients have improved. Clinical trials registered with www.clinicaltrials.gov (NCT01093482).

Lung function and organ dysfunctions in 178 patients requiring mechanical ventilation during the 2009 influenza A (H1N1) pandemic.

INTRODUCTION: Most cases of the 2009 influenza A (H1N1) infection are self-limited, but occasionally the disease evolves to a severe condition needing hospitalization. Here we describe the evolution of the respiratory compromise, ventilatory management and laboratory variables of patients with diffuse viral pneumonitis caused by pandemic 2009 influenza A (H1N1) admitted to the ICU. METHOD: This was a multicenter, prospective inception cohort study including adult patients with acute respiratory failure requiring mechanical ventilation (MV) admitted to 20 ICUs in Argentina between June and September of 2009 during the influenza A (H1N1) pandemic. In a standard case-report form, we collected epidemiological characteristics, results of real-time reverse-transcriptase--polymerase-chain-reaction viral diagnostic tests, oxygenation variables, acid-base status, respiratory mechanics, ventilation management and laboratory tests. Variables were recorded on ICU admission and at days 3, 7 and 10. RESULTS: During the study period 178 patients with diffuse viral pneumonitis requiring MV were admitted. They were 44 ± 15 years of age, with Acute Physiology And Chronic Health Evaluation II (APACHE II) scores of 18 ± 7, and most frequent comorbidities were obesity (26%), previous respiratory disease (24%) and immunosuppression (16%). Non-invasive ventilation (NIV) was applied in 49 (28%) patients on admission, but 94% were later intubated.Acute respiratory distress syndrome (ARDS) was present throughout the entire ICU stay in the whole group (mean PaO2/FIO2 170 ± 25). Tidal-volumes used were 7.8 to 8.1 ml/kg (ideal body weight), plateau pressures always remained < 30 cmH2O, without differences between survivors and non-survivors; and mean positive end-expiratory pressure (PEEP) levels used were between 8 to 12 cm H2O. Rescue therapies, like recruitment maneuvers (8 to 35%), prone positioning (12 to 24%) and tracheal gas insufflation (3%) were frequently applied. At all time points, pH, platelet count, lactate dehydrogenase assay (LDH) and Sequential Organ Failure Assessment (SOFA) differed significantly between survivors and non-survivors. Lack of recovery of platelet count and persistence of leukocytosis were characteristic of non-survivors. Mortality was high (46%); and length of MV was 10 (6 to 17) days. CONCLUSIONS: These patients had severe, hypoxemic respiratory failure compatible with ARDS that persisted over time, frequently requiring rescue therapies to support oxygenation. NIV use is not warranted, given its high failure rate. Death and evolution to prolonged mechanical ventilation were common outcomes. Persistence of thrombocytopenia, acidosis and leukocytosis, and high LDH levels found in non-survivors during the course of the disease might be novel prognostic findings.