RESUMEN
BACKGROUND: Aspiration is a serious clinical concern in patients with long-term artificial airways. The purpose of this study was to determine the reliability of a bedside colored dye assessment of aspiration in tracheostomized patients and to determine its comparability to a more sophisticated videofluoroscopic study. METHODS: This was a prospective, blinded comparison study conducted in a large, urban, university teaching hospital. We studied 20 consecutive patients who underwent tracheostomy for bronchial hygiene needs and who were referred for videofluorographic evaluation for suspected oropharyngeal dysphagia and possible aspiration. Excluded were patients unable to follow verbal commands and those requiring mechanical ventilatory support. All patients were brought to the videofluorography suite for colored dye assessment for aspiration and videofluorographic assessment of oropharyngeal swallow. A nurse, blinded to the results of videofluorographic swallow study, performed colored dye assessments for aspiration. Speech-language pathologists, blinded to the results of the colored dye assessments, interpreted simultaneous (preliminary) and subsequent complete (final) videofluorographic evaluations of swallow. RESULTS: The colored dye aspiration assessments and the videofluoroscopic studies were compared for the frequency of aspiration detection. Sensitivity and specificity were determined using standard methods. Seven patients showed no aspiration on either the colored dye test or videofluoroscopic examination. Eight patients were judged to aspirate by videofluorography but not by the colored dye test. Five patients were judged to aspirate by both the colored dye test and videofluorography. The data indicate that the colored dye test for aspiration carries a low sensitivity of 38% (95% confidence interval = +/- 7%), but a high specificity of 100%. The videofluoroscopic study detected a significantly greater frequency of aspiration than did the colored dye test (p < 0.01). CONCLUSIONS: The colored dye test for aspiration can provide useful information when positive, but because there is a significant false negative rate, decisions made on the basis of a negative test must be made with caution.
Asunto(s)
Inhalación , Sistemas de Atención de Punto , Traqueostomía , Adulto , Anciano , Femenino , Fluoroscopía , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Sensibilidad y EspecificidadRESUMEN
Critically ill patients often have cardiopulmonary perturbations that require rapid and frequent assessment for optimal care, including cardiac output determinations, measurement of cardiac filling pressures, and arterial and mixed venous blood gas determinations. We evaluated the performance of a rapid, on-demand bedside blood gas monitor to determine arterial and mixed venous blood gas values. The blood gas monitor uses fluorescent optode technology to directly measure Po2, Pco2, and pH. This measurement is accomplished by aspirating blood from the artery or vein into a sampling chamber where it interfaces with the fluorescent optode. After approximately 90 s of equilibration, the blood gas values are reported. Since the blood is drawn into the sampling chamber, it can be returned to the patient, thus eliminating the need for phlebotomy. We studied 15 critically ill patients requiring systemic and pulmonary arterial catheterization. Conventional blood gas analysis was performed simultaneously. The results obtained from the blood gas monitor were compared with those obtained via traditional blood gas analysis using Bland-Altman plots and examination of bias and precision. The results were well within the expected clinical variance. During the study period, there was no interference with patient care or adverse events related to the use of the monitoring system. In conclusion, the blood gas monitor can provide rapid, accurate determinations of arterial and mixed venous blood gases allowing optimal therapeutic interventions in critically ill patients.
Asunto(s)
Análisis de los Gases de la Sangre/instrumentación , Sistemas de Atención de Punto , Arteria Pulmonar , Adulto , Anciano , Anciano de 80 o más Años , Estudios de Evaluación como Asunto , Femenino , Humanos , Masculino , Persona de Mediana EdadRESUMEN
OBJECTIVES: To compare microbial contamination of two different blood conservation devices; to determine if there was an association between contamination of the blood conservation devices and clinical infections; to determine if there was a significant user preference for either of the two devices. DESIGN: Prospective, randomized trial. SETTING: Medical, neurosurgical, and spinal cord intensive care units of an urban, university hospital. PATIENTS: Forty patients who required clinically indicated intrafierial catheters placed at new sites. INTERVENTIONS: The two most widely available blood conservation devices at the time of the study (Venous Arterial blood Management Protection system [VAMP], Baxter Edwards Critical-Care, Irvine, CA; and Safe Draw, Ohmeda, Madison, WI) were chosen for comparison. After the normal 48 to 72 hrs of device use, the blood conservation systems were removed and semi-quantitative and quantitative cultures were taken from comparable sites of the two devices. Positive cultures from the patients were recorded and correlated with cultures obtained from the devices. In order to assess preference for either device, a survey tool was administered to the nursing staff who participated in the study. MEASUREMENTS AND MAIN RESULTS: Quantitative cultures from all sites cultured in both groups demonstrated mean colony counts of < 10(3) colony-forming units (cfu)/mL. There were no statistically significant differences in the colony counts at any of the sites compared between the two groups. There were no statistically significant relationships between positive cultures and patient age, gender, duration of device utilization, frequency of device entry, or the intensive care unit in which the study was conducted. In no circumstance did positive cultures from any of the blood conservation devices correlate with positive culture results from any sites of clinical infection. The clinical survey demonstrated a statistically significant preference for the VAMP system, which persisted despite increased experience with the Safe Draw system. CONCLUSIONS: The levels of microbial contamination noted in these devices were not consistent with clinical infection (defined as 10(3) cfu/mL on quantitative cultures). There was no significant difference in degree or pattern of contamination between the two devices. When utilized and changed according to the Centers for Disease Control guidelines, blood conservation devices are not harbors of infection in the critical care setting. Blood conservation devices can be used as part of a comprehensive blood conservation program in the critical care setting without undue concern for exacerbating infectious processes.