Physiological variables of the "metabolic component" of acid-base balance and mortality in intensive care patients / Variables fisiológicas del "componente metabólico" del estado ácido base y mortalidad en pacientes de cuidados intensivos

Abstract Introduction: Metabolic acidosis is a frequent pathophysiological condition in critically ill patients. It can be assessed using different physiological variables, but their prognostic value has not yet been well established. Objective: To evaluate the association between the variables that allow assessing the metabolic component of acid-base balance (ABB) and 28-day mortality in patients admitted to an intensive care unit (ICU) in Bogotá, D.C., Colombia. Materials and methods: Prospective cohort study conducted in 122 patients admitted to an ICU between January and June 2013 and with a stay >24 hours. On admission to the ICU, blood samples were taken, and an arterial blood gas test was performed in order to calculate the following variables: anion gap (AG), corrected anion gap (AGc), standard base excess (BEst), metabolic H+, base excess-unmeasurable anions (BEua), arterial pH, arterial lactate, standard HCO3-st, and strong ion difference (SID). APACHE II and SOFA scores were also calculated. A bivariate analysis was performed in which ORs and their respective 95%CI were calculated, and then a multivariate analysis was conducted using a logistic regression model to identify the variables associated with 28-day mortality; a significance level of p<0.05 was considered. Results: Out of the 122 patients, 33 (27.05%) died at 28 days and 51 (48.80%) were women. Participants' mean age was 46.5 years (±15.7). The following variables were significantly associated with 28-day mortality in the bivariate analysis: SID (OR=1.150; p=0.008), BEua (OR=0.897; p=0.023), AG (OR=1.231; p=0.002), AGc (OR=1.232; p=0.003), blood pH (OR=0.001; p=0.023), APACHE II (OR=1.180; p=0.001), HCO3-st (OR=0.841; p=0.015). In the multivariate analysis, only the APACHE II score variable was significantly associated with 28-day mortality (OR=1.188; p=0.008). Conclusion: The physiological variables that allow assessing the metabolic component of ABB, both from the Henderson model and the Stewart model, were not significantly associated with 28-day mortality.

Resumen Introducción. La acidosis metabólica es una condición fisiopatológica frecuente en pacientes críticamente enfermos. Esta alteración es evaluada mediante diferentes variables fisiológicas; sin embargo, su valor pronóstico aún no está bien definido. Objetivo. Evaluar la asociación entre, por una parte, las variables del componente metabólico que permiten valorar el estado ácido base (EAB) y, por la otra, la mortalidad a 28 días en pacientes hospitalizados en una unidad de cuidados intensivos (UCI) en Bogotá D.C., Colombia. Materiales y métodos. Estudio de cohorte prospectivo realizado en 122 pacientes hospitalizados en una UCI entre enero y junio de 2013 y con una estancia mayor a 24 horas. Se tomaron muestras sanguíneas y gases arteriales de ingreso a UCI para el cálculo de las siguientes variables: anion gap (AG), anion gap corregido (AGc), base exceso estándar (BEst), H+ metabólicos, base exceso-aniones no medibles (BEua), pH arterial, lactato arterial, HCO3-st y brecha de iones fuertes (BIF). También se calcularon el puntaje APACHE II y el puntaje SOFA. Se realizó un análisis bivariado en el que se calcularon OR y sus respectivos IC95%, y luego uno multivariado, mediante un modelo de regresión logística, para identificar las variables asociadas con la mortalidad a 28 días; se consideró un nivel de significancia de p<0.05 Resultados. De los 122 pacientes, 33 (27.05%) fallecieron a 28 días y 51 (48.80%) eran mujeres. La edad promedio fue 46.5 años (±15.7). En el análisis bivariado, las siguientes variables se asociaron significativamente con la mortalidad a 28 días: BIF (OR=1.150; p=0.008), BEua (OR=0.897; p=0.023), AG (OR=1.231; p=0.002), AGc (OR=1.232; p=0.003), pH arterial (OR=0.001; p=0.023), APACHE II (OR=1.180;p=0.001), HCO3-st (OR=0.841;p=0.015). En el análisis multivariado, solo el puntaje APACHE II se asoció significativamente con la mortalidad a 28 días (OR=1.188; p=0.008). Conclusión. Las variables fisiológicas que permiten evaluar el componente metabólico del EAB, tanto las del modelo de Henderson, como las del modelo de Stewart, no se asociaron significativamente con la mortalidad a 28 días.

Spontaneous pneumomediastinum. case report

ABSTRACT Introduction: Spontaneous pneumomediastinum (SPM) is defined as the presence of air in the mediastinum. It is a rare entity considered benign and self-limiting, which mostly affects young adults. Its diagnosis is confirmed through clinical and radiological studies. Case description: 21-year-old male patient with cough and greenish expectoration for four days, associated with dyspnea, chest pain, fever and bilateral supraclavicular subcutaneous emphysema. Chest X-ray suggested pneumomediastinum, which was confirmed by tomography. The patient was hospitalized for observation and treatment. After a positive evolution, he was discharged on the sixth day. Discussion: SPM is a differential diagnosis in patients with chest pain and dyspnea. Its prevalence is lower than 0.01% and its mortality rate is low. It should be suspected in patients with chest pain and subcutaneous emphysema on physical examination. Between 70 and 90% of the cases can be identified by chest X-ray, while confirmation can be obtained through chest tomography. In most cases it does not require additional studies. Conclusion: SPM is a little known cause of acute chest pain, and rarely considered as a differential diagnosis; it is self-limited and has a good prognosis.

Infected pulmonary infarction case report / Infarto pulmonar infectado. reporte de caso

ABSTRACT Introduction: Pulmonary infarction occurs in 29% to 32% of patients with pulmonary thromboembolism (PTE). The infection of a pulmonary infarction is a complication in approximately 2 to 7% of the cases, which makes it a rare entity. Case Presentation: 49-year-old woman with pleuritic pain in the left hemithorax that irradiated to the dorsal region, associated with dyspnea and painful edema in the left lower limb of two days of evolution. Two weeks prior to admission, the patient suffered from a left knee trauma that required surgical intervention; however, due to unknown reasons, she did not receive antithrombotic prophylaxis. Physical examination showed tachycardia, tachypnea and painful edema with erythema in the left leg. After suspecting a pulmonary thromboembolism, anticoagulation medication was administered and a chest angiotomography was requested to confirm the diagnosis. The patient experienced signs of systemic inflammatory response, and respiratory deterioration. A control tomography was performed, suggesting infected pulmonary infarction. Antibiotic treatment was initiated, obtaining progressive improvement; the patient was subsequently discharged, and continued with anticoagulation medication and follow-up on an outpatient basis. Conclusions: Pulmonary infarction is a frequent complication in patients with PTE. Therefore, infected pulmonary infarction should be suspected in patients with clinical deterioration and systemic inflammatory response. The radiological difference between pulmonary infarction and pneumonia is not easily identified, thus the diagnostic approach is clinical, and anticoagulant and antimicrobial treatment should be initiated in a timely manner.

RESUMEN Introducción El infarto pulmonar ocurre entre un 29 y un 32% de pacientes con tromboembolismo pulmonar (TEP). Por su parte, la infección de un infarto pulmonar complica aproximadamente del 2 al 7% de los casos, lo que hace que el infarto pulmonar infectado sea una entidad poco frecuente. Descripción del caso Mujer de 49 años con dolor pleurítico en hemitórax izquierdo, irradiado a región dorsal, asociado a disnea y edema doloroso de miembro inferior izquierdo de dos días de evolución. Dos semanas antes de su ingreso la paciente sufrió trauma de rodilla izquierda, el cual que requirió intervención quirúrgica; sin embargo, por motivos desconocidos, no recibió profilaxis anti trombótica. En el examen físico se encontró taquicardia, taquipnea y edema doloroso con eritema en pierna izquierda. Al existir alta sospecha de tromboembolia pulmonar se inició anticoagulación y se solicitó angiotomografía de tórax, con la cual fue posible confirmar el diagnóstico. Durante su evolución, la paciente experimentó signos de respuesta inflamatoria sistémica, deterioro respiratorio. Se realizó tomografía de control sugestiva de infarto pulmonar infectado. Se inició antibiótico y la paciente mejoró de forma progresiva; después de esta mejora, fue dada de alta para continuar anticoagulación y seguimiento ambulatorios. Conclusiones El infarto pulmonar es una complicación frecuente en pacientes con TEP. Por lo tanto, debe sospecharse infarto pulmonar infectado en pacientes con deterioro clínico y respuesta inflamatoria sistémica. La diferencia radiológica entre infarto pulmonar y neumonía no es fácil de identificar, su enfoque diagnóstico es clínico y el tratamiento anticoagulante y antimicrobiano debe iniciarse de manera oportuna.