[Usefulness of transcutaneous carbon dioxide pressure monitoring to measure blood gases in adults hospitalized for respiratory disease]. / Utilidad de la presión transcutánea del anhídrido carbónico en la valoración gasométrica de adultos hospitalizados con enfermedad respiratoria.

OBJECTIVE: To evaluate the usefulness of transcutaneous carbon dioxide pressure (TcPCO2) monitoring in patients hospitalized for respiratory disease. PATIENTS AND METHODS: We used a SenTec TcPCO2 monitor that also determines transcutaneous oxygen saturation (SpO2) by means of a sensor placed behind the ear lobe at a temperature of 42 degrees C. We compared arterial blood gas measurements--PaCO2 and arterial oxygen saturation (SaO2)--with transcutaneous measurements and analyzed the correlation, regression line, and agreement between the 2 methods. RESULTS: Thirty patients (20 men and 10 women) with various respiratory diseases and a mean (SD) age of 71 (13) years were included in the study. The median TcPCO2 was 43.25 mm Hg and the median PaCO2 was 42.6 mm Hg with no significant differences between the 2 measurements. The correlation was significant (rho=0.979; P< .0001) and the corresponding regression equation was TcPCO2=-2.475+1.058 PaCO2. The mean difference was 0.16 mm Hg (95% confidence interval [CI], --0.74 to 1.06). The lower limit of agreement (mean -1.96 SD) was -4.64 mm Hg, and the upper limit (mean +1.96 SD) was 4.96 mm Hg. For SaO2, the median was 94% and for SpO2, 95%. The difference between the 2 medians was significant (P< .004). The correlation was also significant (rho=0.822; P< .0001) with SpO2=4.427+0.97 SaO2. The mean difference was 1.14% (95% CI, 0.381% to 1.899%). The lower limit of agreement (mean -1.96 SD) was --2.93% and the upper limit (mean +1.96 SD) was 5.21% CONCLUSIONS: Transcutaneous determination of carbon dioxide pressure and oxygen saturation is useful for patients hospitalized for respiratory disease in view of its good correlation and agreement, although SpO2 does tend to overestimate SaO2.

Utilidad de la presión transcutánea del anhídrido carbónico en la valoración gasométrica de adultos hospitalizados con enfermedad respiratoria / Usefulness of transcutaneous carbon dioxide pressure monitoring to measure blood gases in adults hospitalized for respiratory disease

Objetivo: Estudiar la utilidad de la medida de la presión transcutánea de anhídrido carbónico (PtcCO2) en pacientes con enfermedad respiratoria hospitalizados. Pacientes y métodos: Utilizamos el analizador de PtcCO2 SenTec®, que también determina la saturación transcutánea de oxígeno (SpO2), mediante un sensor colocado en el lóbulo de la oreja a una temperatura de 42 °C. Se compararon los valores gasométricos ­--presión arterial de anhídrido carbónico (PaCO2) y saturación arterial de oxígeno (SaO2)--­ con los transcutáneos, analizando la correlación, recta de regresión y la concordancia entre ambos métodos. Resultados: Se incluyó a 30 pacientes (20 varones y 10 mujeres) con diversas enfermedades respiratorias, con una media (± desviación estándar [DE]) de edad de 71 ± 13 años. La mediana de la PtcCO2 era de 43,25 mmHg, y la de la PaCO2 de 42,6 mmHg, sin existir diferencias entre ellas. La correlación era significativa (ρ = 0,979; p < 0,0001), siendo la PtcCO2 = -­2,475 + 1,058 PaCO2. La media de las diferencias fue de 0,16 mmHg (intervalo de confianza del 95%, de ­-0,74 a 1,06); la media de las diferencias menos 1,96 DE fue de ­-4,64 mmHg, y más 1,96 DE, de 4,96 mmHg. En cuanto a la SaO2, la mediana era del 94%, y la de la SpO2 del 95%, con diferencias entre ambas (p < 0,004). La correlación fue significativa (ρ = 0,822; p < 0,0001), con SpO2 = 4,427 + 0,97 SaO2. La media de la concordancia era del 1,14% (intervalo de confianza del 95%, 0,381-1,899%); la media menos 1,96 DE era del ­-2,93%, y más 1,96 DE, del 5,21%. Conclusiones: La determinación transcutánea de anhídrido carbónico y de la SaO2 es de utilidad en pacientes con enfermedad respiratoria hospitalizados, dada su buena correlación y concordancia, aunque la SpO2 tiende a sobrevalorar la SaO2

Objective: To evaluate the usefulness of transcutaneous carbon dioxide pressure (TcPCO2) monitoring in patients hospitalized for respiratory disease. Patients and methods: We used a SenTec TcPCO2 monitor that also determines transcutaneous oxygen saturation (SpO2) by means of a sensor placed behind the ear lobe at a temperature of 42ºC. We compared arterial blood gas measurements--PaCO2 and arterial oxygen saturation (SaO2)--with transcutaneous measurements and analyzed the correlation, regression line, and agreement between the 2 methods. Results: Thirty patients (20 men and 10 women) with various respiratory diseases and a mean (SD) age of 71 (13) years were included in the study. The median TcPCO2 was 43.25 mm Hg and the median PaCO2 was 42.6 mm Hg with no significant differences between the 2 measurements. The correlation was significant (ρ=0.979; P<.0001) and the corresponding regression equation was TcPCO2=­-2.475+1.058 PaCO2. The mean difference was 0.16 mm Hg (95% confidence interval [CI], ­-0.74 to 1.06). The lower limit of agreement (mean ­-1.96 SD) was ­-4.64 mm Hg, and the upper limit (mean +1.96 SD) was 4.96 mm Hg. For SaO2, the median was 94% and for SpO2, 95%. The difference between the 2 medians was significant (P<.004). The correlation was also significant (ρ=0.822; P<.0001) with SpO2=4.427+0.97 SaO2. The mean difference was 1.14% (95% CI, 0.381% to 1.899%). The lower limit of agreement (mean ­1.96 SD) was ­-2.93% and the upper limit (mean +1.96 SD) was 5.21% Conclusions: Transcutaneous determination of carbon dioxide pressure and oxygen saturation is useful for patients hospitalized for respiratory disease in view of its good correlation and agreement, although SpO2 does tend to overestimate SaO2