- 學位論文
使用改良式NUTRIC評分系統評估重症病患的營養狀況及給予不同型式營養支持後對臨床結果的影響
The assessment of nutritional risk by applying modified NUTRIC scoring system and the effects of different types of nutritional feedings on clinical outcomes in critically ill patients
摘要
重症病患急性期熱量給予多寡與預後的關係在近年研究中一直有爭議。早期觀察性研究指出重症病患若有較高的熱量攝取會改善預後；之後幾篇大型隨機分派介入研究中指出熱量攝取與預後無關；但是近期ESPEN (European Society for Clinical Nutrition and Metabolism)重症營養指引卻建議重症病患在急性期時應攝取較低熱量(< 70%預估熱量)。有關重症病患的熱量攝取與臨床結果的相關性需要進一步的確認。重症病患間因有較高的異質性及相異的營養狀況，適當的熱量攝取值可能需要參考病患的營養風險做修正。但是過去研究少有根據重症病患的營養風險，以前瞻隨機分派方式給予不同目標熱量，探討重症病患的熱量攝取。因此，我們以一系列的研究探討重症病患的熱量攝取策略與營養風險及臨床結果的相關性。 第一個研究是以病歷回溯方式比較在加護病房導入以攝取量為基礎的灌食流程(volume-based feeding protocol)前後的臨床結果差異，以及探討熱量的攝取與重症病患臨床結果的相關性。此研究回溯並記錄導入灌食流程前的214位重症病患以及導入灌食流程後的198位重症病患的臨床結果資料。結果顯示雖然重症病患熱量攝取達成率(實際熱量攝取量/預估熱量需求量)從導入灌食流程前的57.7%上升到導入灌食流程後的70.3%，但是灌食流程前後的死亡率卻沒有降低。進一步資料分析後發現不論有無導入灌食流程，只要重症病患的實際熱量攝取量大於預估熱量需求量的65%即可顯著降低加護病房死亡率(odds ratio: 1.6; 95% confidence interval, 1.01 – 2.47)。 足夠的熱量攝取量雖可以改善重症病患的臨床結果，但是重症病患間的異質性極高，給予適合重症病患的熱量攝取量時或許需要考量病患本身的營養狀況。美國腸道靜脈營養學會與重症醫學會發表的重症營養指引建議應以營養風險評估工具[如：nutritional risk screening 2002 (NRS 2002)、營養風險評估量表(Nutrition Risk in the Critically ill score, NUTRIC score)或改良式營養風險評估量表(modified Nutrition Risk in the Critically ill score, mNUTRIC score)]評估重症病患的營養狀況。因此第二個研究以病歷回溯的橫斷面設計評估重症病患的營養風險對熱量攝取與臨床結果關係的影響。以mNUTRIC score回溯評估742位重症病患的營養風險後，75.3%病患屬於高營養風險，183位病患屬於低營養風險。高營養風險病患攝取超過800 kcal/day的熱量時，會顯著降低住院死亡率、14天死亡率與28天死亡率，但是低營養風險病患的熱量攝取與臨床結果並無顯著相關性。高營養風險病患相較低營養風險病患更應注重熱量的攝取。 前述研究雖已確認是高營養風險病患的熱量攝取與臨床結果有顯著相關性，但是不確定何種熱量攝取型態適用於何種營養風險的重症病患。因此第三個前瞻式介入研究是探討不同營養風險的重症病患其熱量攝取型態與臨床結果的相關性。重症病患依照mNUTRIC score的結果分派為高營養風險及低營養風險組別。相同營養風險的重症病患被隨機分派到滋養性灌食或是全熱量灌食組別，共分成四組，分別為高營養風險全熱量灌食(n = 50)、高營養風險滋養性灌食(n = 56)、低營養風險全熱量灌食(n = 24)與低營養風險滋養性灌食(n = 20)。經過6天的不同灌食策略後，結果顯示四組的臨床結果，包含住院死亡率、14天死亡率、28天死亡率、呼吸器使用天數、加護病房留置天數與住院天數皆無顯著差異。四組的熱量與蛋白質攝取量與臨床結果皆無顯著相關性。但是低營養風險病患接受滋養性灌食後的蛋白質攝取量若越高，則其住院天數與加護病房滯留天數也越高。除了熱量攝取外，重症病患的蛋白質攝取量與臨床結果的相關性需要進一步探討。 總結三個研究，回溯研究發現熱量攝取量與重症病患，尤其高營養風險病患，的死亡率有顯著相關性。此外，高營養風險病患若能每天攝取大於800千卡的熱量可以降低住院死亡率、14天死亡率與28天死亡率。但是前瞻性隨機分派介入研究卻顯示不同營養風險病患的熱量攝取型態與臨床結果無顯著相關性。
並列摘要
The appropriate amount of energy delivery in the acute phase of critically ill patients is still controversial. Observational studies have shown that a high energy intake can improve the clinical outcomes of critically ill patients, whereas recent large randomized control trials (RCTs) have shown no difference in clinical outcomes with regards to energy intake in critically ill patients. Moreover, the European Society for Clinical Nutrition and Metabolism (ESPEN) guidelines on clinical nutrition in the intensive care unit (ICU) recommend energy intake less than 70% of estimated energy intake in the acute phase of critically ill patients. Therefore, further studies are needed to identify the relationship between energy intake and clinical outcomes in critically ill patients. Patients’ characteristics are highly heterogeneous, and their nutritional status varies in the ICU. Accordingly, the patient’s individualized nutritional risk should be considered to determine their optimal energy delivery. However, few RCTs have investigated energy delivery based on a patient’s nutritional risk. Herein, we conducted a series of studies to clarify the clinical dilemma regarding individualized energy delivery strategies in patients with different nutritional risk levels. In the first study, we compared differences in clinical outcomes before and after the implementation of a volume-based feeding protocol (pre-FP vs. FP) by retrospectively reviewing medical records. The study enrolled 214 critically ill patients in the pre-FP group and 198 critically ill patients in the FP group. Actual energy intake increased from 57.7% of estimated energy intake in the pre-FP group to 70.3% of estimated energy intake in the FP group. However, there was no significant difference in hospital mortality before and after implementation of the feeding protocol. In further statistical analysis, we observed that an energy intake greater than 65% of estimated energy intake reduced ICU mortality regardless of whether the feeding protocol had been implemented (odds ratio: 1.6; 95% confidence interval, 1.01 – 2.47). Critically ill patients are highly heterogeneous. Although sufficient energy intake may improve their clinical outcomes, their individual nutritional status should also be considered to provide optimal energy delivery. According to the recommendations of the American Society for Parenteral and Enteral Nutrition (ASPEN)/ Society of Critical Care Medicine (SCCM) guidelines for the provision and assessment of nutritional support therapy in critically ill adult patients, the nutritional risk of all ICU patients should be evaluated by using tools such as the Nutritional Risk Screening 2002, (NRS 2002), Nutrition Risk in the Critically Ill (NUTRIC) score, or modified Nutrition Risk in the Critically Ill (mNUTRIC) score. We thus conducted a second retrospective cohort study to investigate the effects of nutritional status of critically ill patients on the association between energy intake and clinical outcomes. The mNUTRIC score was retrospectively applied to stratify patients into high and low nutritional risk groups. There were 559 patients (75.3%) in the high nutritional risk group and 183 patients in the low nutritional risk group. Hospital mortality, 14-day mortality and 28-day mortality significantly reduced if the energy intake was greater than 800 kcal/day in the patients with a high nutritional risk. However, this finding was not seen in the patients with a low nutritional risk. This suggests that critically ill patients at high nutritional risk should have an energy intake of at least 800 kcal/day. Previous studies have shown promising results on the association between energy intake and clinical outcomes. However, it is not clear which energy delivery strategy is most suitable for critically ill patients with different nutritional risk levels. The third study was a prospective intervention study which investigated the association between either full or trophic energy intake with clinical outcomes in patients with high or low nutritional risk. All eligible patients were assigned to either a high or low nutritional risk group based on their mNUTRIC score, and were then randomized to receive either trophic feeding or full feeding. The four study groups were therefore: high nutritional risk with full feeding (n = 50), high nutritional risk with trophic feeding (n = 56), low nutritional risk with full feeding (n = 24), and low nutritional risk with trophic feeding (n = 20). The results showed that there were no significant differences in hospital mortality, 14-day mortality, 28-day mortality, ventilator dependency, days of ICU stay and days of hospital stay among the four groups. In further statistical analysis, we observed that protein intake was positively associated with days of ICU stay and hospital stay in the low nutritional risk with trophic feeding group. Further studies are warranted to investigate the relationship between protein intake and clinical outcomes in critically ill patients. In conclusion, the two retrospective studies revealed that high energy intake was associated with lower ICU mortality, especially in patients at high nutritional risk. An energy intake greater than 800 kcal/day in patients at high nutritional risk reduced hospital mortality, 14-day mortality and 28-day mortality. However, the prospective randomized interventional study showed no differences in clinical outcomes between different energy intake strategies in patients at either high or low nutritional risk.