• 作者：M. S&#225 ; nchez Casado<sup>asup><sup> ; sup><sup>marcel55@terra.essup> ; M. Quintana Dí ; az<sup>bsup> ; D. Palacios<sup>asup> ; V. Hortigü ; ela<sup>asup> ; C. Marco Schulke<sup>asup> ; J. Garcí ; a<sup>csup> ; A. Canabal<sup>asup> ; M.J. Pé ; rez Pedrero<sup>asup> ; A. Velasco Ramos<sup>asup> ; M.A. Arrese<sup>asup>
• 关键词：Gradiente alveolo-arterial de oxí ; geno ; PaFi ; PaO2/FiO2 ; Da&ntilde ; o pulmonar
• 刊名：Medicina Intensiva
• 出版年：2012
• 期刊代码：pca255_02105691
• 类别：med
• 出版时间：June-July, 2012
• 卷：36
• 期：5
• 页码：329-334
• 文件大小：469 K

lass="h4">Objectives

To determine whether the alveolar-arterial oxygen gradient (Grad[A-a]O<sub>2sub>) helps confirm the influence of PEEP on PaFi (PaO<sub>2sub>/FiO<sub>2sub>).

lass="h4">Design

Observational study; we used linear regression to perform a multivariate study to improve the PaFi formula by taking PEEP into account.

lass="h4">Setting

Tertiary hospital.

lass="h4">Patients

We included all patients who were admitted to the intensive care unit, regardless of pulmonary damage.

lass="h4">Variables

We recorded personal history, clinical judgment, intensive care data, severity scores on the first day and progression. Two calculated variables: PaFi and Grad(A-a)O<sub>2sub>.

lass="h4">Results

A total of 956 patients were included: 63.9%men; median age 68 years. On the first day, 31.8%did not have mechanical ventilation (MV), 13.1%had non-invasive MV and 55.1%had invasive MV. PaFi values: 32.9%0-200, 32.2%201-300, and 34.8%>300. PEEP values: 0-5 69.8%, 6-10 27.5%and >10 2.6%. We observed a correlation (Pearson) between Grad(A-a)O<sub>2sub> and PaFi of -0.84 (p &lt; 0.001). On performing multiple regression (dependent variable: Grad[A-a]O<sub>2sub>), the following variables were included in the model: PaFi, PEEP, APACHE IV and SOFA; coefficient of determination (R<sup>2sup>) of 0.62 without PEEP and 0.72 with PEEP. We changed the PaFi formula, referring to it as PaFip (PaFi plus PEEP): Ln (PaFi/[PEEP + 12]). Correlation index between PaFip and Grad(A-a)O<sub>2sub>: -0.9 (p &lt; 0.001). We performed linear regression (dependent variable: Grad[A-a]O<sub>2sub>) and used PaFip instead of PaFi. Only PaFi remained in the model, and was discretely complemented by APACHE IV; R<sup>2sup> = 0.8.

lass="h4">Conclusions

By adding PEEP to the PaFi model (PaFip), we clearly improve the latter, as reflected by a better goodness of fit.