Coordinación de Nutrición Clínica, Departamento de Áreas Críticas, Instituto Nacional de Enfermedades Respiratorias, Mexico City, Mexico.
Sección de Estudios de Posgrado e Investigación, Escuela Superior de Medicina, Instituto Politécnico Nacional, Mexico City, Mexico.
JPEN J Parenter Enteral Nutr. 2024 Nov;48(8):974-981. doi: 10.1002/jpen.2685. Epub 2024 Sep 22.
Phase angle (PhA) obtained by bioelectrical impedance analysis (BIA) works as a predictor of clinical outcomes. Specific cutoff values for longitudinal changes and their relationship with clinical outcomes are still undetermined for patients with critical illness. Thus, the aim of this study was to analyze the association between longitudinal changes in PhA during intensive care unit (ICU) stay and all-cause 90-day mortality in patients critically ill with COVID-19.
This was a retrospective cohort study of adults critically ill with COVID-19 undergoing invasive mechanical ventilation with a length of stay >14 days. BIA was performed at ICU admission and at days 7 and 14 of ICU stay; PhA and hydration parameters were collected. Differences between survivors and nonsurvivors were assessed. Longitudinal changes were evaluated using repeated-measures analysis of variance. A receiver operating characteristics curve for PhA declined (%) during the first 14 days, and all-cause 90-day mortality was performed. Survival probability was reported using hazard ratios (HR).
One-hundred nine patients were included. The change in the value of PhA was close to 17.1%. Nonsurvivors had a higher prevalence of individuals with a decrease in PhA >22.2% (area under the curve = 0.65) in the first 14 days in comparison with survivors (70% vs 34.8%, P < 0.01). PhA decrease >22.2% at 14 days was a significant predictor of all-cause 90-day mortality (HR = 2.2, 95% CI 1.71-3.6, P = 0.04).
Changes in PhA are associated with all-cause 90-day mortality. Future studies should be directed to interventions to prevent changes in this nutrition marker.
生物电阻抗分析（BIA）获得的相位角（PhA）可作为临床结局的预测指标。对于危重病患者，纵向变化的特定临界值及其与临床结局的关系仍未确定。因此，本研究旨在分析 ICU 住院期间 PhA 的纵向变化与 COVID-19 危重病患者全因 90 天死亡率之间的关系。
这是一项回顾性队列研究，纳入了接受有创机械通气且 ICU 住院时间>14 天的 COVID-19 危重病成年患者。在 ICU 入院时和 ICU 住院第 7 天和第 14 天进行 BIA；收集 PhA 和水合参数。评估幸存者和非幸存者之间的差异。使用重复测量方差分析评估纵向变化。进行 PhA 下降（%）在最初 14 天的受试者工作特征曲线分析，并进行全因 90 天死亡率分析。使用危险比（HR）报告生存概率。
共纳入 109 例患者。PhA 值的变化接近 17.1%。与幸存者相比，非幸存者中 PhA 下降>22.2%（曲线下面积=0.65）的患者比例更高（70% vs 34.8%，P<0.01）。在第 14 天，PhA 下降>22.2%是全因 90 天死亡率的显著预测因素（HR=2.2，95%CI 1.71-3.6，P=0.04）。
PhA 的变化与全因 90 天死亡率相关。未来的研究应针对干预措施，以防止这种营养标志物的变化。
