Interpretación de gases arteriovenosos. Una guía práctica. Revisión de tema / Interpretation of arteriovenous gases. A practical guideline. A review

La evaluación del estado ácido base y de la oxigenación de un paciente es fundamental en cualquier escenario clínico, sea en consulta externa, en un servicio de urgencias, hospitalización, en cirugía o en la unidad de cuidado intensivo. El conocimiento de las bases fisiopatológicas es de suma importancia para el entendimiento y adecuada interpretación de estas condiciones. El objetivo de esta revisión es proveer las bases de conocimiento necesarias para el abordaje adecuado de los gases arteriovenosos y proponer un modelo para la compresión e interpretación de estos. Este artículo aborda las bases fisiopatológicas de las alteraciones ácido base, los modelos existentes en su compresión, el modelo propuesto para su abordaje diagnóstico, sus diagnósticos diferenciales, el enfoque de la hipoxemia, la interpretación de los gases arteriovenosos y las variables que se pueden obtener de estos, el enfoque de la acidosis láctica y unos ejemplos del modelo propuesto.

The evaluation of the acid-base status and the oxygenation of a patient is fundamental in any clinical setting, be it in an outpatient clinic, in an emergency service, hospitalization, in surgery or in the intensive care unit. Knowledge of the pathophysiological bases is of the utmost importance for the understanding and adequate interpretation of these conditions. The objective of this review is to provide the necessary knowledge for the adequate understanding of arteriovenous gases and to propose a model for their comprehension and interpretation. This article addresses the pathophysiological bases of acid-base disorders, the existing models in their comprehension, the model proposed for their diagnostic approach, their differential diagnoses, the diagnostic approach to hypoxemia, the interpretation of arteriovenous gases and the variables that can be obtained from them, the diagnostic approach of lactic acidosis and some examples of the proposed model.

Actinomyces in the mediastinum. Surprise is key in all art.

Introduction: Actinomycosis is an unusual chronic granulomatous infectious disease. They are commensals in various sites of the human body but with little pathogenicity. Actinomyces israelii is the most prevalent species but more than 30 species have been described. Infection of the lower respiratory tract is unusual, the involvement of mediastinum being even rarer. Case report: A 63-year-old man, previously healthy and living in a rural area, presented with a 5-month history of hemoptysis, pleuritic pain, weight loss, and night sweats. Community-acquired pneumonia with a mediastinal mass was documented, for which he received antibiotic management. Thoracoscopy was carried out for diagnosis and resection of the mediastinal mass due to inconclusive findings in the percutaneous biopsy. Pathology reported the presence of filamentous Gram-positive bacteria visible in Grocott staining. Due to the pathology findings, and the fact that no other infectious agents were identified, a diagnosis of actinomycosis was established. Treatment with oral amoxicillin 1g TID for 6 months was initiated. Conclusions: As far as we are aware, we present the sixth case of mediastinal actinomycosis. We present this case to bring attention to this rare but clinically relevant presentation to be considered as a differential diagnosis of mediastinal masses and to emphasize the need for specific anaerobic cultures to improve the diagnostic yield.

Hafnia alvei pneumonia: from bees to human beings.

INTRODUCTION: Hafnia alvei is an enterobacteria that is a common inhabitant of the gastrointestinal flora of bees, birds, fish, and mammals. In humans this enterobacteria has been recovered from the oropharynx and the gastrointestinal tract but it has been rarely reported as a pathogen and usually identified as hospital-acquired enterobacteria. CASE REPORT: We describe a case of a 57-year-old woman, previously healthy, with a 7-day history of cough with brown sputum, sudden onset of chills, subjective fever, malaise, and pleuritic pain in the right hemithorax. A diagnosis of community-acquired pneumonia (CAP) was suspected and empiric antibiotic treatment was started. However, the patient showed no response and developed hemoptysis. A diagnosis of CAP by Hafnia alvei was confirmed with bronchoalveolar lavage and the patient was treated with i.v. cefepime 2 g TID with a good response. CONCLUSIONS: We presented a case of community-acquired pneumonia by Hafnia alvei in a previously healthy patient that, as far as our knowledge reaches, is the third reported case of CAP secondary to this pathogen.

Lemierre's syndrome by Bacillus circulans, Fusobacterium nucleatum and Staphylococcus aureus with involvement of the internal and external jugular vein.

INTRODUCTION: Lemierre's syndrome refers to the septic thrombophlebitis of the internal jugular vein, secondary to a pharyngeal infection. Although it mainly affects the internal jugular vein, isolated cases have been described of involvement of the external jugular vein. The main etiological agent is Fusobacterium necrophorum. CASE REPORT: A 27-year-old male, previously healthy, presented with a 7-day history of sore throat and fever. He was diagnosed with Lemierre's syndrome, coinfection by Bacillus circulans, F. nucleatum and Staphylococcus aureus with an atypical presentation due to the involvement of the external jugular vein and the internal jugular vein. CONCLUSIONS: As far as we are aware, we present the first case of Lemierre's syndrome with these characteristics.

Subarachnoid racemose neurocysticercosis with cerebellar involvement: an old friend in an infrequent location?

Taenia solium is the most common parasitic infection of the central nervous system and it can cause parenchymal or extra-parenchymal lesions. Subarachnoid cysticercosis is a type of extra-parenchymal infection in which the prevalence is not known and racemose NC with cerebellar involvement has been rarely reported. The diagnosis is challenging because of its similarity to other infectious diseases or to subarachnoid involvement of systemic malignancies. Treatment usually requires cysticide drugs, however, there are no randomized studies concerning the anti-parasitic treatment in subarachnoid NC. We present a case of racemose NC in the cerebellar hemisphere to draw attention to this pathology, endemic in many parts of the world; and highlight all the current gaps in our understanding of this entity.

Enfermedad de Behçet frente a la enfermedad inflamatoria intestinal. Diferencias en la presentación clínica / Behçet's disease compared with inflammatory bowel disease. Differences in their clinical presentation

Resumen La enfermedad de Behçet es una enfermedad poco frecuente con un compromiso sistémico cuyas principales manifestaciones abarcan el sistema gastrointestinal, neurológico, vascular y articular, además de la piel y los ojos. Por su compromiso multisistémico, es frecuente confundirlo con otras entidades como la enfermedad inflamatoria intestinal, con la cual comparte gran parte de su presentación clínica, por lo que se describe un caso clínico y se aborda una revision narrativa desde el punto de vista epidemiológico de las manifestaciones clínicas con el fin de tener un mayor conocimiento para identificarla a tiempo.

Abstract Behçet's disease is a rare disease with systemic involvement whose main manifestations include the gastrointestinal, neurological, vascular, and articular systems, as well as the skin and eyes. Due to its multisystemic nature, it is often mistaken for other entities such as inflammatory bowel disease since they share multiple characteristics in their clinical presentation. A clinical case is described, and an epidemiological review of clinical manifestations is discussed to have better knowledge that allow identifying it on time.