足量蛋白质营养支持可改变低肌肉量重症患者的六个月死亡风险
最佳的蛋白质及能量摄入量可以降低重症监护病房（ICU）机械通气患者的死亡率，然而在不同肌肉量患者中的影响尚不明确。
荷兰阿姆斯特丹自由大学通过腹部CT第3腰椎水平肌肉面积对患者肌肉量进行分类，将687例重症患者分为低肌肉面积组（男性＜170cm²、女性＜110cm²）及正常组。
结果发现，在正常肌肉面积组中，高蛋白质摄入（≥1.2g/kg/d）与低蛋白质摄入（＜1.2g/kg/d）的患者6个月死亡率无统计学差异（P=1.00）。在低肌肉面积组中，高蛋白质摄入患者6个月死亡率（36.6%）明显低于低蛋白质摄入患者（52.6%）。此外，高蛋白质摄入与死亡率呈负相关（P=0.011），而在正常肌肉面积组无统计学意义（P=0.897）。同样，生存曲线显示高蛋白质摄入与低蛋白质摄入患者之间在低肌肉面积组存在统计学差异（P=0.019），但是在正常肌肉面积组无差异（P=0.720）。
因此，在低肌肉量ICU患者中，早期足量蛋白质摄入（≥1.2g/kg/d）可以改善其6个月生存率。
JPEN J Parenter Enteral Nutr. 2017;41(2):267.
Adequate protein nutrition support modifies 6-month mortality risk of low muscle mass in critically ill patients.
Wilhelmus G. P. M. Looijaard WGPM, Ingeborg M. Dekker, Heleen M. Oudemans-van Straaten, Peter J. M. Weijs.
VU University Medical Center Amsterdam, Amsterdam, Netherlands.
PURPOSE: Optimal protein and energy intake have been shown to be relevant for reducing mortality in prospective observational studies in mechanically ventilated patients admitted to the intensive care unit (ICU). However, nutrition status (muscle mass) of patients at admission and its consequences for clinical outcome are largely unknown. Computerized tomography (CT) scans can be used to assess muscle mass as a proxy for body protein mass.
METHODS: This is a retrospective, observational study in patients admitted to the ICU of the VU University Medical Center from September 2003 to April 2013. Patients with an ICU stay of at least 5 days and a CT scan of the abdomen performed between 4 days before up to 4 days after admission to the ICU were included. Data on sex, age, body mass index (BMI), Acute Physiology and Chronic Health Evaluation (APACHE) II score, and protein and energy intake were collected. Protein intake is presented in g/kg on day 4 of ICU admission. Day 4 was chosen as indicator of early intake, in line with the Dutch national nutrition performance indicator. High protein (HP) intake was defined as protein intake ≥1.2 g/kg, in line with current ICU guidelines. Slice-O-Matic software (TomoVision, Montreal, Canada) was used by certified investigators (WL, ID) for CT scan analysis. Muscle area (cm²) was assessed at the third lumbar vertebra level. Low muscle area was defined as <110 cm² for females and <170 cm² for males (PMID: 24410863). Energy intake strata were made based on mean energy intake on days 1–4 expressed as percentage of resting energy expenditure estimated by the Harris-Benedict equation: stratum 1, <80%; stratum 2, 80%–120%; and stratum 3, >120%. In this abstract, we report on stratum 2 (eg, the patients who were well fed based on their energy intake between 80% and 120% of estimated energy requirement). Cox regression analysis was used to determine the hazard ratio (HR) for 6-month mortality for protein intake ≥1.2 g/kg compared with <1.2 g/kg in the group of patients with low muscle mass and the group with normal muscle mass separate, with adjustments for APACHE II score. Kaplan-Meier survival curves with log rank test were made for both low and normal muscle mass groups.
RESULTS: A total of 687 cases was included with complete data: 414 in stratum 1, 221 in stratum 2, and 52 in stratum 3. Stratum 2: male percentage was 63%, mean age was 59 ± 18 years, and mean BMI was 25 ± 4 kg/m². Of the 221 patients, 63% had low muscle area (mean 120 ± 27 cm²) and 37% normal muscle area (mean 171 ± 44 cm²). The normal muscle group showed a 6-month mortality of 18.5%, with no significant difference between protein intake ≥1.2 g/kg vs <1.2 g/kg (18.0% vs 14.3%, P = 1.00). The low muscle group showed a 6-month mortality of 45.3%. Six-month mortality tended to be lower for protein intake ≥1.2 g/kg vs <1.2 g/kg (36.6% vs 52.6%, P = .121). High protein intake was associated with lower 6-month mortality in the low muscle group (HR, 0.49; 0.28–0.88; P = .011), but not in the normal muscle group (HR, 1.09; 0.30–3.98; P = .897). In the low muscle group, survival curves were significantly different between higher protein intake and lower protein intake (log rank P = .019), while this was not the case in the normal muscle group (P = .720).
CONCLUSIONS: In critically ill patients with low muscle mass at ICU admission receiving adequate energy intake, an early high protein intake of ≥1.2 g/kg/d is associated with a lower 6-month mortality. This association was not found in patients admitted with normal muscle mass.
FINANCIAL SUPPORT: Baxter Healthcare.
DOI: 10.1177/0148607116686023