背景：許多研究評估各種前負荷指標、心搏量變異率與心輸出指數的相關性，但所得結果不一。 本研究目的是探討使用呼吸器病人的(1) 全心舒張末期容積指數、(2) 胸內血容積指數、(3) 中心靜脈壓、(4) 心搏量變異率與心輸出指數的相關性。
方法：本研究為前瞻性相關性研究。於台灣北部一醫學中心內科加護病房收案60 位使用呼吸器及 心肺容積監視器病人。透過中心靜脈導管獲得中心靜脈壓。利用經肺式熱稀釋法由心肺容 積監視器獲得全心舒張末期容積指數、胸內血容積指數、心搏量變異率和心輸出指數。
結果：36 位男性和24 位女性病患，平均年齡68.15 歲。研究結果發現心搏量變異率和心輸出指數 呈負相關(r = - .281, p = .03)；而全心舒張末期容積指數、胸內血容積指數、中心靜脈壓和 心輸出指數皆無顯著相關。
結論：使用呼吸器的內科病人，在監測心輸出指數且考量是否需輸液時，心搏量變異率具參考價值；但這結果不能應用於心律不整以及正接受血液透析的病人。

Background: Many studies have evaluated the relationships among various preload indicators, stroke volume variation (SVV), and cardiac index (CI); however, the results have been inconsistent. The purposes of the study were to explore the relationships among (1) global end-diastolic volume index (GEDVI) and CI, (2) intrathoracic blood volume index (ITBVI) and CI, (3) central venous pressure (CVP) and CI, and (4) stroke volume variation (SVV) and CI in patients receiving mechanical ventilation.
Methods: This was a prospective correlational study design. The study was performed in a medical intensive care unit (ICU) of a medical center in northern Taiwan. Sixty patients receiving mechanical ventilation and pulse-induced contour cardiac output (PiCCO) were included. The CVP value was obtained by connecting the central line to the bedside monitor. GEDVI, ITBVI, SVV, and CI were determined via transpulmonary thermodilution measurements.
Results: There were 36 males and 24 females with a mean age of 68.15 years. SVV was significantly and negatively related to CI (r = - .281, p = .03). However, GEDVI, ITBVI, and CVP were not significantly related to CI.
Conclusions: For medical patients receiving mechanical ventilation, SVV could be used as a reference when monitoring cardiac index and considering if fluid infusion is needed. These results could not apply to patients with arrhythmias or receiving hemodialysis.