Papers by Marcelo Mercado
Respiratory Medicine Case Reports, 2013
Tuberculosis (TB) is an uncommon cause of severe respiratory failure, even in highly endemic regi... more Tuberculosis (TB) is an uncommon cause of severe respiratory failure, even in highly endemic regions. Mortality in cases requiring mechanical ventilation (MV) varies between 60 and 90%. The use of extracorporeal membrane oxygenation (ECMO) is not frequently needed in TB. We report the case of a 24 year old woman diagnosed with bilateral pneumonia that required MV and intensive care, patient was managed with prone ventilation for 48 h, but persisted in refractory hypoxemia. Etiological study was only positive for mycobacterium tuberculosis. As a rescue therapy arterio-venous extracorporeal CO2 removal was started and lased for 4 days, but fails to support the patient due to greater impairment of oxygenation. Veno-venous ECMO was then initiated, thus normalizes gas exchanged and allows lungs to rest. ECMO was maintained for 36 days, with two episodes of serious complication treated successfully. Given the absence of clinical improvement and the lack of nosocomial infection, at 42-day of ICU stay methylprednisolone 250 mg daily for 4 days was started, since secondary organizing pneumonia associated with TB was suspected. Thereafter progressive improvement in pulmonary mechanics and reduction of pulmonary opacities was observed, allowing the final withdrawal of ECMO. Percutaneous tracheostomy was performed and the patient remained connected until her transfer to her base hospital at day 59 of admission to our unit. The tracheostomy was removed prior to hospital discharge, and the patient is today at home. Prolonged ECMO support is a useful and potentially successful tool in catastrophic respiratory failure caused by TB.
Revista médica de Chile (Impresa), Jan 3, 2012
To recognize the etiological agent responsible for severe acute respiratory failure (ARF) in pati... more To recognize the etiological agent responsible for severe acute respiratory failure (ARF) in patients in mechanical ventilation (MV) is important to determine their treatment and prognosis, and to avoid the excessive use of antibiotics. Mini bronchoalveolar lavage (mini BAL) is a blind, non bronchoscopic procedure, used to obtain samples from the lower respiratory tract from patients on mechanical ventilation (MV). To assess the feasibility, complications and preliminary results of mini BAL among patients with severe ARF on MV. Prospective study in 17 patients with acute lung injury (ALI ) or acute respiratory distress syndrome (ARDS) on MV and with negative conventional microbiological studies. Mini BAL was performed using standardized protocols. Hemodynamic and respiratory parameters where measured before and after the procedure. Samples obtained were sent to quantitative cultures. At baseline: APACHE II score of 22 ± 6,7, PaO2/FiO2 ratio was 176.6 ± 48.6 and the oxygenation index...
Revista medica de Chile, 2007
Acute pulmonary edema caused by thiazides is uncommon and of difficult diagnosis. It is considere... more Acute pulmonary edema caused by thiazides is uncommon and of difficult diagnosis. It is considered an idiosyncratic reaction and the physiopathology or cardiac function changes are not well known. We report a 60 year-old female with a thiazide induced acute pulmonary edema who was followed with serial measurements of type B n-terminal natriuretic peptide fraction as marker for cardiac dysfunction. There was a significant elevation of the peptide, not associated to evidences of ventricular dysfunction. Its normalization paralleled the resolution of the clinical picture.
Los pacientes que cursan tromboembolismo, dependiendo de su severidad, pueden recibir variados tr... more Los pacientes que cursan tromboembolismo, dependiendo de su severidad, pueden recibir variados tratamientos no exentos de efectos adversos. Existe, por lo tanto, la necesidad de estratificar riesgo -magnitud- mortalidad con criterios que le permitan al clinico tomar las mejores decisiones. En este articulo se pretende establecer un sistema de aproximacion al tromboembolismo pulmonar de acuerdo a la informacion hasta ahora disponible. (AU)
![Research paper thumbnail of [Hemodynamic impact of positive end expiratory pressure (PEEP) during severe respiratory failure: present view]](https://a.academia-assets.com/images/blank-paper.jpg)
Bedside evaluation of pulmonary mechanics and thoracic computed axial tomography have changed the... more Bedside evaluation of pulmonary mechanics and thoracic computed axial tomography have changed the ventilatory management of patients suffering an acute respiratory failure caused by adult respiratory distress syndrome (ARDS). Mortality has been reduced limiting tidal volumes, which avoids alveolar overdistention and by the use of positive end expiratory pressure (PEEP), that reduces the damage caused by cyclical alveolar collapse-reopening. Nowadays, it is well known that inappropriate mechanical ventilation enhances lung damage caused by the underlying disease. However, the optimal adjustment of PEEP is not yet established. Usually, it is not easy to achieve an equilibrium between an optimal lung recruitment without producing alveolar overdistention and hemodynamic adverse effects such as hypotension and reduction of cardiac output. This paper reviews the interactions between heart and lung.
![Research paper thumbnail of [Physiopathology of acute renal failure during sepsis]](https://attachments.academia-assets.com/76569536/thumbnails/1.jpg)
Medicina intensiva / Sociedad Española de Medicina Intensiva y Unidades Coronarias, 2011
Acute renal failure (ARF) is an independent risk factor associated with increased mortality durin... more Acute renal failure (ARF) is an independent risk factor associated with increased mortality during sepsis. Recent consensus definitions have allowed the standardization of research on the subject. The understanding of the physiopathology of ARF during sepsis is limited by the scarcity of histological studies and the inability to measure renal microcirculatory flows. Historically, ARF during sepsis has been considered to be a consequence of diminished renal blood flow (RBF). Indeed, in early stages of sepsis or in sepsis associated to cardiogenic shock, RBF may decrease. However, recent studies have shown that in resuscitated sepsis, in which cardiac output is characteristically normal or even elevated and there is systemic vasodilatation, RBF is normal or even increased, with no associated histological evidence of significant tubular necrosis. Thus, other factors may participate in the genesis of ARF in sepsis. These include apoptosis, glomerular and medullary microcirculatory disor...
criticalcareshock.org
Purpose: To study inflammatory profile in patients with sepsis, severe sepsis and septic shock wi... more Purpose: To study inflammatory profile in patients with sepsis, severe sepsis and septic shock with regards to organ dysfunction and outcome, and to identify a pattern associated with more catastrophic course of illness, organ failure and risk of death.
Rev Chil Med Intensiv, 2005
![Research paper thumbnail of [Mini bronchoalveolar lavage in patients with severe respiratory failure]](https://attachments.academia-assets.com/69428149/thumbnails/1.jpg)
Revista medica de Chile
To recognize the etiological agent responsible for severe acute respiratory failure (ARF) in pati... more To recognize the etiological agent responsible for severe acute respiratory failure (ARF) in patients in mechanical ventilation (MV) is important to determine their treatment and prognosis, and to avoid the excessive use of antibiotics. Mini bronchoalveolar lavage (mini BAL) is a blind, non bronchoscopic procedure, used to obtain samples from the lower respiratory tract from patients on mechanical ventilation (MV). To assess the feasibility, complications and preliminary results of mini BAL among patients with severe ARF on MV. Prospective study in 17 patients with acute lung injury (ALI ) or acute respiratory distress syndrome (ARDS) on MV and with negative conventional microbiological studies. Mini BAL was performed using standardized protocols. Hemodynamic and respiratory parameters where measured before and after the procedure. Samples obtained were sent to quantitative cultures. At baseline: APACHE II score of 22 ± 6,7, PaO2/FiO2 ratio was 176.6 ± 48.6 and the oxygenation index...
Revista médica de Chile, 2011
Mini bronchoalveolar lavage in patients with severe respiratory failure Background: To recognize ... more Mini bronchoalveolar lavage in patients with severe respiratory failure Background: To recognize the etiological agent responsible for severe acute respiratory failure (ARF) in patients in mechanical ventilation (MV) is important to determine their treatment and prognosis, and to avoid the excessive use of antibiotics. Mini bronchoalveolar lavage (mini BAL) is a blind, non bronschoscopic procedure, used to obtain samples from the lower respiratory tract from patients on mechanical ventilation (MV). Aim: To assess the feasibility, complications and preliminary results of mini BAL among patients with severe ARF on MV. Material and Methods: Prospective study in 17 patients with acute lung injury (ALI) or acute respiratory distess syndrome (ARDS) on MV and with negative conventional microbiological studies. Mini BAL was performed using standardized protocols. Hemodynamic and respiratory parameters where measured before and after the procedure. Samples obtained were sent to quantitative cultures. Results: At baseline: APACHE II score of 22 ± 6,7, P a O 2 /F i O 2 ratio was 176.6 ± 48.6 and the oxygenation index was 9.74 ± 3.78. All procedures were performed by an ICU resident. Thirty fi ve percent of the procedures had positive cultures and no complications related to the procedures were reported. The procedure lasted an average of 12 minutes and the instilled and rescued volume were 60 ml and 19.6 ml, respectively. There were no signifi cant differences between hemodynamic and respiratory variables before and after the procedure. Conclusions: Mini BAL is a safe, fast and easy technique for obtaining samples from the inferior airway in patients with ALI or ARDS on MV.
Revista médica de Chile, 2003
We report a 68 years old man, farmer from the metropolitan region, admitted with a Hantavirus Car... more We report a 68 years old man, farmer from the metropolitan region, admitted with a Hantavirus Cardiopulmonary Syndrome. The diagnosis was made using serologic test and was later confirmed by the Public Health Institute. He evolved to an early multiple organ failure, requiring high concentrations of oxygen and invasive ventilatory assistance, vasopressor drugs and renal replacement therapy. Swan Ganz and PiCCO were used simultaneously for hemodynamic monitoring. Treatment consisted in global support therapy, antimicrobial therapy and systemic corticosteroids. Intrathoracic blood volume was a more reliable parameter than pulmonary capillary wedge pressure for the assessment of preload. As expected in situations of increased vascular permeability, there was an increase in extravascular lung water. There was a good correlation between extravascular lung water and oxygenation parameters (PaO2/FiO2 and oxygenation index). PiCCO system may become a helpful tool in the management of patient...
Revista médica de Chile, 2005
Cardiac output can be measured non invasively by transesophageal Doppler. This is an alternative ... more Cardiac output can be measured non invasively by transesophageal Doppler. This is an alternative to measure it by thermodilution with a catheter in the pulmonary artery. To compare both methods of cardiac output measurement. Simultaneous measurement of cardiac output by transesophageal Doppler and thermodilution with a catheter in the pulmonary artery in four male critical patients, aged 60+/-12 years, hospitalized in a University Hospital. The Bland and Altman method to compare the concordance between two measurements, was used. Forty measurements were performed. The results of both methods had a correlation coefficient of 0.98. According to the Bland and Altman method, the difference between both methods was -0.5 L with a precision of 0.52 L/min (95% confidence interval -1.51 to 0.52 L/min). Considering that a change between two sequential measurements is considered significant when the difference is more than 15%, both measurements agreed in 83% of cases, that there was a change ...
Revista médica de Chile, 2007
Background: Severe sepsis (SS) is the leading cause of death in the Intensive Care Units (ICU). A... more Background: Severe sepsis (SS) is the leading cause of death in the Intensive Care Units (ICU). Aim: To study the prevalence of SS in Chilean ICUs. Material and methods: An observational, cross-sectional study using a pre-designed written survey was done in all ICUs of Chile on April 21st, 2004. General hospital and ICU data and the number of hospitalized patients in the hospital and in the ICU at the survey day, were recorded. Patients were followed for 28 days. Results: Ninety four percent of ICUs participated in the survey. The ICU occupation index was 66%. Mean age of patients was 57.7±18 years and 59% were male, APACHE II score was 15±7.5 and SOFA score was 6±4. SS was the admission diagnosis of 94 of the 283 patients (33%) and 38 patients presented SS after admission. On the survey day, 112 patients fulfilled SS criteria (40%). APACHE II and SOFA scores were significantly higher in SS patients than in non SS patients. Global case-fatality ratio at 28 days was 15.9% (45/283). Case-fatality ratio in patients with or without SS at the moment of the survey was 26.7% (30/112) and 8.7% (17/171), respectively p <0.05. Thirteen percent of patients who developed SS after admission, died. Case-fatality ratios for patients with SS from Santiago and the other cities were similar, but APACHE II score was significantly higher in patients from Santiago. In SS patients, the independent predictors of mortality were SS as cause of hospital admission, APACHE II and SOFA scores. Ninety nine percent of SS patients had a known sepsis focus (48% respiratory and 30% abdominal). Eighty five patients that presented SS after admission, had a respiratory focus. Conclusions: SS is highly prevalent in Chilean ICUs and represents the leading diagnosis at admission. SS as cause of hospitalization, APACHE II and SOFA scores were independent predictors of mortality (Rev Méd Chile 2007; 135: 620-30).
Revista médica de Chile, 2005
Comparison of cardiac output measurement in critical patients using transesophageal D oppler or t... more Comparison of cardiac output measurement in critical patients using transesophageal D oppler or thermodilution. A preliminary report Background: Cardiac output can be measured non invasively by transesophageal Doppler. This is an alternative to measure it by thermodilution with a catheter in the pulmonary artery. Aim: To compare both methods of cardiac output measurement. Material and methods: Simultaneous measurement of cardiac output by transesophageal Doppler and thermodilution with a catheter in the pulmonary artery in four male critical patients, aged 60±12 years, hospitalized in a University Hospital. The Bland and Altman method to compare the concordance between two measurements, was used. Results: Forty measurements were performed. The results of both methods had a correlation coefficient of 0.98. According to the Bland and Altman method, the difference between both methods was-0.5 L with a precision of 0.52 L/min (95% confidence interval-1.51 to 0.52 L/min). Considering that a change between two sequential measurements is considered significant when the difference is more than 15%, both measurements agreed in 83% of cases, that there was a change in cardiac output. Conclusions: Transesophageal Doppler is a promising non invasive technique to measure cardiac output in critical care patients. It becomes a valid alternative to the thermodilution technique. This preliminary experience must be confirmed in a larger series (Rev Méd Chile 2005; 133: 761-6).
Critical Care, 2008
In order to find out the frequency rates of domestic and wild animal bites as well as the evaluat... more In order to find out the frequency rates of domestic and wild animal bites as well as the evaluation of the prevalence rates of rabies disease in the human population in the Province of Kerman, a retrospective study was designed to analyze statistically the collected recorded data related to this project. Methods This study was conducted within the framework of MPVM student research projects by means of collaboration
Critical Care, 2008
In order to find out the frequency rates of domestic and wild animal bites as well as the evaluat... more In order to find out the frequency rates of domestic and wild animal bites as well as the evaluation of the prevalence rates of rabies disease in the human population in the Province of Kerman, a retrospective study was designed to analyze statistically the collected recorded data related to this project. Methods This study was conducted within the framework of MPVM student research projects by means of collaboration
Revista médica de Chile, 2003
Revista médica de Chile, 2012
The prognosis of pulmonary thromboembolism (PE) is related to the cardiopulmonary reserve of the ... more The prognosis of pulmonary thromboembolism (PE) is related to the cardiopulmonary reserve of the patient and the magnitude of the embolus that impacts pulmonary circulation. The presence of hemodynamic instability (shock) stratifies a group of patients with high mortality, which should be treated with thrombolysis. Patients without shock but with right ventricular dysfunction can have a dismal evolution and should be managed aggressively. CAT scan, echocardiography and serum markers can be of value to define patients with a higher mortality. The available evidence to define the best diagnostic and therapeutic strategy is scanty, controversial and inconclusive. A good combination of clinical, imaging and biological markers should be defined to identify those patients without shock but with a high rate of complications and mortality, that could benefit from aggressive treatments.
Revista médica de Chile, 2013
Massive pulmonary embolism (PE) is associated with high mortality. There is still a broad assortm... more Massive pulmonary embolism (PE) is associated with high mortality. There is still a broad assortment of severity classifications for patients with PE, which affects the choice of therapies to use. The main clinical criteria for defining a PE as massive is systemic arterial hypotension, which depends on the extent of vascular obstruction and the previous cardiopulmonary status. Right ventricular dysfunction is an important pathogenic element to define the severity of patients and short term clinical prognosis. The recommended treatment is systemic thrombolysis, but in centers with experience and resources, radiological invasive therapies through catheters are useful alternatives that can be used as first choice tools in certain cases. (Rev Med Chile 2013; 141: 486-494).
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Papers by Marcelo Mercado