BACKGROUND: Despite increasing use of tympanic thermometers in critically ill patients who do not have a pulmonary artery catheter in place, variations in measurements obtained with the thermometers are still a problem. OBJECTIVE: To compare the range of variability between tympanic and oral electronic thermometers. METHODS: Subjects were a convenience sample of 72 patients admitted to a 24-bed adult medical-surgical intensive care unit. For each patient, temperatures were measured concurrently (within a 1-minute period) with an oral (Sure Temp 678) thermometer, a pulmonary artery catheter (Baxter VIP Swan-Ganz Catheter), and 2 tympanic (FirstTemp Genius II and ThermoScan Ear Pro-1) thermometers. Each subject was used up to 3 times for data collection. Measurements obtained with the oral and tympanic thermometers were compared with those obtained with the pulmonary artery catheter. Nonparametric analysis of data was used. RESULTS: The magnitude of error for the ThermoScan tympanic thermometer differed significantly from that of the Genius II tympanic thermometer and the SureTemp oral thermometer (P < .001). Application of the Bland and Altman method to frame the data on the basis of an accuracy tolerance zone of +/-0.5 degrees C indicated variability with both the oral and tympanic methods. The overall degree of variability was lower for the oral thermometer. CONCLUSIONS: Oral thermometers provide less variable measurements than do tympanic thermometers. Use of oral thermometry is recommended as the best practice method for temperature evaluation in critical care patients when measurement of core temperature via a pulmonary artery catheter is not possible.
BACKGROUND: Measurements of central venous pressure are generally obtained through one of the three ports of centrally placed triple-lumen catheters. However, no scientifically based literature is available that guides clinical practice and indicates which of the lumens is most appropriate for obtaining these measurements. OBJECTIVE: To determine if a difference exists between measurements of central venous pressure obtained via the proximal, medial, and distal ports of a triple-lumen catheter. METHODS: Measurements of central venous pressure in 48 adult ICU patients were obtained via each of the three ports of a triple-lumen catheter. Catheters were placed in either the right or left subclavian vein or the right or left internal jugular vein. The flush system was single-transducer, trifurcated pressure tubing system. Data were evaluated for variation among the three ports of the catheter for readings taken at a single point. RESULTS: A repeated-measures analysis of variance showed significant differences across port sites. Post hoc univariate F tests showed significant differences between the proximal and distal ports and between the medial and distal ports. In some patients, the difference between central venous pressure obtained from the distal port and pressure obtained from the proximal or the medial port may be clinically significant. CONCLUSION: Because measurements of central venous pressure may not always be comparable for all three ports of a triple-lumen catheter, care should be taken to distinguish when changes in pressure readings are a result of a change in port site rather than in the patient's condition.