Aim: Critical ill patients experience catabolic stress which results in the systemic inflammatory response. The inflammatory response is associated with increased complications including infection, multi-organ dysfunction, increased length of ICU stays, and mortality. L-Carnitine supplementation may play an important role in these patients by regulating inflammatory cell function. The purpose of the present study was to investigate the effect of L-Carnitine supplementation on clinical status, inflammatory markers, and mortality rate in critically ill patients admitted in the intensive care unit(ICU) Methods: This randomized, double-blind, placebo-controlled trial was performed on critically ill patients. Subjects were randomly assigned into placebo (n=27) and L-Carnitine (n=27) groups. L-Carnitine (3000mg/day) was administered via nasogastric tube for the intervention group for 7 days while the other group received a placebo for the same duration. Serum levels of inflammatory markers including C-reactive protein (CRP) and interleukin-6 (IL-6) were measured. Nutritional status and the acute physiology and chronic health evaluation (APACHE) score, sequential organ failure assessment (SOFA) score, and 28-day mortality were also recorded. Results: Fifty-one critically ill patients completed the study. L-Carnitine supplementation significantly reduced the levels of CRP (mean change± SE: -34.9 ± 6.5) and IL-6 (mean change ±SE: -10.64 ± 2.16) compared to the baseline, which are both statistically significant compared with the control group (p<0.05). The SOFA and APACHE scores were significantly reduced in the L-Carnitine group compared with the placebo group (p=0.02 and p<0.001, respectively). Conclusions: L-Carnitine supplementation has substantial beneficial effects on inflammatory and clinical outcomes of critically ill patients.

Enteral immunomodulatory nutrition is suggested as an adjuvant therapy for patients admitted in intensive care units (ICU), but its effectiveness remains debated. The aim of this systematic review and meta-analysis is to examine the effect of dietary immunomodulatory formula on the clinical outcomes and risk of overall mortality in critically ill patients. PubMed, Scopus and ISI web of Knowledge databases were searched until September 2019. Randomized Controlled Trials (RCTs) that used immunomodulatory diet containing omega-3 fatty acid, γ-linolenic acid and antioxidants in ICU were included. Ten RCTs including 1166 participants were included in the meta-analysis. Immunomodulatory diet containing omega-3 fatty acid, γ-linolenic acid and antioxidants led to significantly reduce the duration of ICU stays (WMD: −2.97 days; 95%CI: -5.59, -0.35), duration of mechanical ventilation (WMD = -2.20 days, 95%CI: -4.29, -0.10), SOFA (sequential organ failure assessment) and MOD (multiple organ dysfunction) score (Hedge’s g: -0.42 U/L; 95% CI: -0.74, -0.11). The 28 days’ overall mortality was remarkably decreased following Immunomodulatory supplement in critically ill patients (RR = 0.74, 95% CI: 0.58, 0.91) and extended the ICU- free days (WMD: 4.06 days, 95%CI: 0.02, 8.09). However, immunomodulatory formula had no significant effect on length of hospital stays, ventilator- free days and level of oxygenation.Immunomodulatory diet containing omega-3 fatty acid, γ-linolenic acid and antioxidants might have beneficial effects for the patient’s residing in ICU; However, further well-designed RCTs with larger sample size are recommended to confirmed its effect.