The accuracy of transcutaneous PCO2 in subjects with severe brain injury: a comparison with end-tidal PCO2.

BACKGROUND: In patients suffering from brain injury, end-tidal PCO2 (PETCO2 ) monitoring is controversial, but transcutaneous PCO2 (PtcCO2 ), which is noninvasive and utilizes immediate display, may be an alternative method. We hypothesized that PtcCO2 would be more accurate than PETCO2 for monitoring PaCO2 in patients with severe brain injury. METHODS: A prospective observational study included consecutive mechanically ventilated adult subjects who had acute brain injury and an arterial catheter in place. When an arterial blood gas analysis was required, the PETCO2 and PtcCO2 values were simultaneously recorded. The agreement between the PETCO2 , PtcCO2 , and PaCO2 measurements (reference) was determined using the Bland-Altman method. The number of outliers defined by the formula ([PETCO2 or PtcCO2 ] - PaCO2 ) > ± 4 mm Hg indicated the proportion of measurements that were considered clinically unacceptable. RESULTS: A total of 25 subjects were included in the study, and 85 simultaneous measurements of PaCO2 , PtcCO2 , and PETCO2 were obtained. The bias and precision between PaCO2 and PtcCO2 were -0.75 and 6.23 mm Hg, respectively. The limits of agreement ranged from -12.97 to 11.47 mm Hg. The bias and precision between PaCO2 and PETCO2 were 0.68 and 5.82 mm Hg, respectively. The limits of agreement ranged from -10.72 to 12.08 mm Hg. There were 34 (40%) outliers for the PtcCO2 sensor and 34 (40%) outliers for the PETCO2 sensor (P > .99). CONCLUSIONS: The accuracy of PtcCO2 was not superior to that of PETCO2 for assessing PCO2 levels and should not be used to monitor these levels in subjects with severe brain injury.

Hand rub dose needed for a single disinfection varies according to product: a bias in benchmarking using indirect hand hygiene indicator.

BACKGROUND: The 3ml volume currently used as the hand hygiene (HH) measure has been explored as the pertinent dose for an indirect indicator of HH compliance. A multicenter study was conducted in order to ascertain the required dose using different products. METHOD: The average contact duration before drying was measured and compared with references. Effective hand coverage had to include the whole hand and the wrist. Two durations were chosen as points of reference: 30s, as given by guidelines, and the duration validated by the European standard EN 1500. Each product was to be tested, using standardized procedures, by three nosocomial infection prevention teams, for three different doses (3, 2 and 1.5ml). RESULTS: Data from 27 products and 1706 tests were analyzed. Depending on the product, the dose needed to ensure a 30-s contact duration in 75% of tests ranging from 2ml to more than 3ml, and to ensure a contact duration exceeding the EN 1500 times in 75% of tests ranging from 1.5ml to more than 3ml. The aftermath interpretation is the following: if different products are used, the volume utilized does not give an unbiased estimation of the HH compliance. Other compliance evaluation methods remain necessary for efficient benchmarking.