Pulsioximetría en el diagnóstico de insuficiencia cardiaca aguda / Pulse oximetry in the diagnosis of acute heart failure

Introducción y objetivos. La saturación de oxígeno mediante pulsioximetría se usa habitualmente en la monitorización de pacientes críticos, pero su utilidad como marcador diagnóstico de insuficiencia cardiaca aguda no ha sido evaluada. Este estudio analiza el papel diagnóstico de la saturación de oxígeno mediante pulsioximetría en una serie de pacientes con infarto agudo de miocardio. Métodos. En un estudio observacional prospectivo, se incluyó a 220 pacientes consecutivos con infarto agudo de miocardio. Se registraron la saturación de oxígeno mediante pulsioximetría basal (sin oxígeno), las constantes fisiológicas, la clase Killip y la puntuación radiológica a la misma hora, durante los primeros 3 días del ingreso. Se siguió a los pacientes durante 1 año. Resultados. Se obtuvieron 612 valoraciones. La saturación de oxígeno mediante pulsioximetría basal disminuyó de forma progresiva respecto a la presencia y la gravedad de la insuficiencia cardiaca, tanto valorada con la clasificación de Killip 1-3 (medias, 95, 92 y 85, respectivamente; p<0,001), como con la puntuación radiológica 0-4 (95, 94, 92, 89 y 83, respectivamente; p<0,001), con un cociente de correlación de 0,66 y 0,63 respectivamente. Las curvas receiver operating characteristic para la saturación de oxígeno mediante pulsioximetría mostraron que el punto de corte <93 tenía la mayor área, con sensibilidad del 65%, especificidad del 90% y precisión diagnóstica del 83%. Los pacientes agrupados según su saturación de oxígeno mediante pulsioximetría más baja, mostraron tasas significativamente distintas de mortalidad o rehospitalización con insuficiencia cardiaca. Conclusiones. La saturación de oxígeno mediante pulsioximetría es útil para establecer el diagnóstico y la gravedad de la insuficiencia cardiaca en situaciones agudas como el infarto de miocardio y puede tener implicaciones pronósticas. El diagnóstico debe sospecharse cuando la saturación de oxígeno mediante pulsioximetría basal es <93 (AU)

Introduction and objectives. Oxygen saturation by pulse oximetry is commonly used for monitoring critical patients, but its utility as a diagnostic marker of acute heart failure has not been assessed. This study analyzed the diagnostic role of oxygen saturation by pulse oximetry in a series of patients with acute myocardial infarction. Methods. In a prospective observational cohort study of 220 consecutive patients with acute myocardial infarction, data collection included baseline oxygen saturation by pulse oximetry (without oxygen), physiologic measurements, Killip class and data from portable chest radiography, recorded at the same hour on each of the first three days after admission. Patients were followed up for one year. Results. There were 612 assessments. Baseline oxygen saturation by pulse oximetry decreased progressively in relation to the presence and the severity of acute heart failure assessed by Killip classes 1 to 3 (mean: 95, 92 and 85, respectively; P<.001) or by radiology score 0 to 4 (95, 94, 92, 89 and 83, respectively; P<.001), with a correlation coefficient of 0.66 and 0.63, respectively. Receiver operating characteristic curves disclosed the cut-off of oxygen saturation by pulse oximetry<93 to have the greatest area, with a sensitivity of 65%, specificity 90%, and overall test accuracy 83%. Patients grouped according to lowest oxygen saturation by pulse oximetry showed significantly different rates of one-year mortality or rehospitalization for heart failure. Conclusions. Baseline oxygen saturation by pulse oximetry is useful in establishing the diagnosis and severity of heart failure in acute settings such as myocardial infarction and may have prognostic implications.The diagnosis may be suspected when baseline oxygen saturation by pulse oximetry is <93 (AU)

Pulse oximetry in the diagnosis of acute heart failure.

INTRODUCTION AND OBJECTIVES: Oxygen saturation by pulse oximetry is commonly used for monitoring critical patients, but its utility as a diagnostic marker of acute heart failure has not been assessed. This study analyzed the diagnostic role of oxygen saturation by pulse oximetry in a series of patients with acute myocardial infarction. METHODS: In a prospective observational cohort study of 220 consecutive patients with acute myocardial infarction, data collection included baseline oxygen saturation by pulse oximetry (without oxygen), physiologic measurements, Killip class and data from portable chest radiography, recorded at the same hour on each of the first three days after admission. Patients were followed up for one year. RESULTS: There were 612 assessments. Baseline oxygen saturation by pulse oximetry decreased progressively in relation to the presence and the severity of acute heart failure assessed by Killip classes 1 to 3 (mean: 95, 92 and 85, respectively; P<.001) or by Radiology Score 0 to 4 (95, 94, 92, 89 and 83, respectively; P<.001), with a correlation coefficient of 0.66 and 0.63, respectively. Receiver operating characteristic curves disclosed the cut-off of oxygen saturation by pulse oximetry<93 to have the greatest area, with a sensitivity of 65%, specificity 90%, and overall test accuracy 83%. Patients grouped according to lowest oxygen saturation by pulse oximetry showed significantly different rates of one-year mortality or rehospitalization for heart failure. CONCLUSIONS: Baseline oxygen saturation by pulse oximetry is useful in establishing the diagnosis and severity of heart failure in acute settings such as myocardial infarction and may have prognostic implications.The diagnosis may be suspected when baseline oxygen saturation by pulse oximetry is <93. Full English text available from:www.revespcardiol.org.

Risk factors for intubation as a guide for noninvasive ventilation in patients with severe acute cardiogenic pulmonary edema.

OBJECTIVE: Noninvasive ventilation may reduce the endotracheal intubation rate in patients with acute cardiogenic pulmonary edema. However, criteria for selecting candidates for this technique are not well established. We analyzed a cohort of patients with severe acute cardiogenic pulmonary edema managed by conventional therapy to identify risk factors for intubation. These factors were used as guide for indications for noninvasive ventilation. DESIGN AND SETTING: Observational cohort registry in the ICU and emergency and cardiology departments in a community teaching hospital. PATIENTS: . 110 consecutive patients with acute cardiogenic pulmonary edema, 80 of whom received conventional oxygen therapy. INTERVENTIONS: Physiological measurements and blood gas samples registered upon admission. MEASUREMENTS AND RESULTS: Twenty-one patients (26%) treated with conventional oxygen therapy needed intubation. Acute myocardial infarction, pH below 7.25, low ejection fraction (<30%), hypercapnia, and systolic blood pressure below 140 mmHg were independent predictors for intubation. Conversely, systolic blood pressure of 180 mmHg or higher showed to be a protective factor since only two patients with this blood pressure value required intubation (8%)], both presenting with a pH lower than 7.25. Considering systolic blood pressure lower than 180 mmHg, patients who showed hypercapnia presented a high intubation rate (13/21, 62%) whereas the rate of intubation in patients with normocapnia was intermediate (6/23, 26%). All normocapnic patients with pH less than 7.25 required intubation. No patient with hypocapnia was intubated regardless the level of blood pressure. CONCLUSIONS: Patients with pH less than 7.25 or systolic blood pressure less than 180 mmHg associated with hypercapnia should be promptly considered for noninvasive ventilation. With this strategy about 40% of the patients would be initially treated with this technique, which would involve nearly 90% of the patients that require intubation.