The Critical Care Nutrition (CCN) Systematic Review process is an ongoing effort to provide the most up-to-date evidence through collecting, evaluating, and analyzing randomized controlled trials (RCTs) related to nutrition in critically ill patients for the critical care nutrition community.
We have included all RCTs of nutritional interventions involving critically ill patients examining clinically important outcomes published since 1980 (see our protocol below). The included studies have undergone a formal review by our review committee and data have been extracted in duplicate.
Starting 2022, we will update the systematic review by topics (not by year anymore). We will update the systematic review of a certain topic once that topic has newly published RCTs that warrants an update. This update will be announced in our Twitter and the publication date will be revised on this page to reflect the update. Please follow our Twitter account @CriticalCareNu1 for the latest update!
We are hoping you find these summaries of evidence updates helpful in your day-to-day practice. Also, we wanted to offer a thank you to our collaborators, past and present, who work on this ongoing activity. This would not be possible without a full team effort
Review Committee:
Dr. Daren Heyland
Zheng-Yii Lee, PhD
Charles Chin Han Lew, PhD
Luis Alfonso Ortiz Reyes, MSc
Dr. Jayshil Patel
Dr. Christian Stoppe
Ellen Dresen, PhD
Dr Aileen Hill
Lauren Tweel
For those interested in citing these systematic reviews, we encourage you to use the following citation:
Heyland DK, Lee Z-Y, Lew CCH, Ortiz LA, Patel J, Stoppe C. [insert the systematic review title]. [insert date of publication]. Critical Care Nutrition.com [insert date accessed].
| Protocol (updated May 2021) |
| 2018 Systematic Reviews |
| No | Topic | Publication Date |
| 1.0 | Indirect calorimetry vs. Predictive equations | July 2021 |
| 2.0 | The use of Enteral vs Parenteral Nutrition | Feb 2021 |
| 3.0 | Enteral Nutrition (EN) | |
| 3.1 | Early vs Delayed EN | May 2021 |
| 3.2 | EN Energy Dose | |
| 3.2a | Achieving Target Dose of EN | Feb 2021 |
| 3.2b | EN: Trophic vs Full Feeds | Feb 2021 |
| 3.2c | Hypocaloric EN | Feb 2021 |
| 4.0 | EN Composition | |
| 4.1 | Pharmaconutrition | |
| 4.1a | Composition of EN: Arginine and Other Nutrients | Feb 2021 |
| 4.1b(i) | Composition of EN: Fish oils, Borage oils and other Antioxidants | Mar 2021 |
| 4.1b(ii) | Composition of EN: Fish oils alone | Feb 2021 |
| 4.1c | Composition of EN: Glutamine | Mar 2021 |
| 4.1d | Composition of EN: Ornithine Ketoglutarate (OKG) | Mar 2021 |
| 4.2 | Composition of Macronutrients | |
| 4.2a | Composition of EN: CHO/Fat: High Fat/Low CHO | Mar 2021 |
| 4.2b | Composition of EN: CHO/Fat: Low Fat/High CHO | Mar 2021 |
| 4.2c | Composition of EN: High vs Low Protein (Published paper Jul 2021) | July 2021 |
| 4.3 | Modification of Macronutrients | |
| 4.3a | Composition of EN: Protein/Peptides | Mar 2021 |
| 4.3b | Composition of EN: Fat Modified | Mar 2021 |
| 4.4 | Composition of EN: pH | Mar 2021 |
| 4.5 | Composition of EN: Fiber | Mar 2021 |
| 4.6 | Composition of EN: Prebiotics/Probiotics/Synbiotics (Published paper Apr 2023) | Apr 2021 |
| 4.7 | Composition of EN: HMB | Mar 2021 |
| 5.0 | EN Feeding Protocols | |
| 5.1 | Feeding protocols (overall or components) | |
| 5.1a | Feeding Protocols | Mar 2021 |
| 5.1b | Body Position | Mar 2021 |
| 5.1c | Fasting | Mar 2021 |
| 5.2 | Motility Agents vs Intestinal Feeding | |
| 5.2a | Use of Motility Agents | Apr 2021 |
| 5.2b | Motility Agents vs Intestinal Feeding | Mar 2021 |
| 5.3 | Gastric Residual Volumes (GRVs) | |
| 5.3a | GRVs Thresholds (New topic) | Mar 2021 |
| 5.3b | GRVs Monitoring (New topic) | Feb 2021 |
| 5.3c | GRVs Frequency (New topic) | Mar 2021 |
| 5.3d | GRVs Discarding | Feb 2021 |
| 6.0 | EN Administration | |
| 6.1 | EN: Closed vs. Open Systems | Mar 2021 |
| 6.2 | EN: Small Bowel vs. Gastric Feeding | May 2021 |
| 6.3 | EN: Continuous vs. Other Methods of Administrations | Apr 2021 |
| 6.4 | EN: Gastrostomy vs. Nasogastric Feeding | Mar 2021 |
| 7.0 | Enteral and Parenteral Nutrition | |
| 7.1 | Combination EN + PN | May 2021 |
| 7.2 | Early vs. Delayed Supplemental PN | Mar 2021 |
| 8.0 | Parenteral Nutrition (PN) | |
| 8.1 | PN vs. Standard Care | Mar 2021 |
| 9.0 | PN Composition | |
| 9.1a | Composition of PN: Protein and Amino Acids (Published paper Jul 2021) | July 2021 |
| 9.1b | Composition of PN: Branched Chain Amino Acids | Apr 2021 |
| 9.2a | Composition of PN: PN Glutamine | Apr 2021 |
| 9.2b | Composition of PN: PN+EN Glutamine | Mar 2021 |
| 9.2c | Composition of PN: PN vs EN Glutamine | Mar 2021 |
| 9.3 | Composition of PN: Type of Lipids (Published paper Jan 2022) | Jan 2022 |
| 10.0 | Strategies to Optimize PN | |
| 10.1 | Strategies to optimize PN: Hypocaloric vs. Standard PN | Mar 2021 |
| 10.2 | Strategies to optimize PN: Use of lipids vs No lipids | Mar 2021 |
| 10.3 | Strategies to optimize PN: Mode of lipid delivery | Mar 2021 |
| 11.0 | Glycemic Control | |
| 11.1 | Optimal glucose control: Insulin therapy | Mar 2021 |
| 11.2 | Optimal glucose control: Carbohydrate restricted formula + insulin therapy | Mar 2021 |
| 12.0 | Micronutrients | |
| 12.1 | Antioxidant Nutrients: Combined Vitamins and Trace Elements | Mar 2021 |
| 12.2 | Parenteral Selenium (alone or in combination) | Feb 2022 |
| 12.3 | Parenteral Zinc (alone or in combination) | Mar 2021 |
| 12.4 | Parenteral Vitamin C (Published paper: 1) monotherapy [Mar 2023]; 2) combination [Mar 2022]) | Nov 2021 |
| 12.5 | Vitamin D (Published paper Sept 2022) | coming soon |
| 12.6 | Thiamine | Mar 2021 |
| 13.0 | Combined High Protein and Early Physical Rehabilitation | Sept 2022 |
| 14.0 | Specific Population | |
| 14.1 | Specific Population: Burn-Glutamine | Apr 2023 |
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