Table 2.
Observational nutrition studies between 2000 and 2010.
| Publication | Population | Duration | Energy delivery (kcal/day) | Key findings |
|---|---|---|---|---|
| Krishnan et al.[55] | 187 MICU patients with ICU LOS ≥96 h | Up to ICU discharge | NR, median 51 (IQR 32–70)% energy adequacy | Energy adequacy of (1) 33–65% vs. 0–32% associated with ↑ likelihood of spontaneous ventilation prior to ICU discharge and (2) ≥66% vs. 0–32% with ↓ likelihood of hospital discharge alive and spontaneous ventilation prior to ICU discharge. |
| Rubinson et al.[53] | 138 MICU patients without oral intake for ≥96 h | Up to ICU discharge | NR, 49% ± 29% energy adequacy | Energy adequacy of <25% vs. ≥25–49%, 50–74% and ≥75% was associated with ↑ risk of nosocomial bloodstream infections. |
| Villet et al.[47] | 48 SICU patients staying ≥5 days in ICU | Up to 4 weeks | 1090 ± 930 | Cumulative energy balance (−12,600 ± 10,520 kcal) was associated with ↑ ICU LOS, complications, infections, days on antibiotics, length of MV. |
| Petros et al.[48] | 61 MICU patients receiving EN for ≥ 7 days | Until ICU discharge or a maximum of 14 days | NR, 86% ± 30% energy adequacy | Patients who achieved a maximum feed volume of 2000 mL or 25 mL/kg by Day 4 (n = 46, 75%) compared to after Day 10 (n = 15, 25%) had a ↓ in ICU mortality. |
| Dvir et al.[49]. | 50 general ICU patients requiring MV ≥ 96 h | ICU admission | 1512 (range 400–3210) | Maximum negative energy balance (−5805 [range: 0 to −17,274] kcal) was associated with ↑ ARDS, sepsis, renal failure, pressure sores, need for surgery, total complication rate. |
| Hise et al.[56] | 77 SICU/MICU patients with LOS ≥ 5 days | Up to ICU discharge | SICU (n = 41): 991 ± 560 MICU (n = 36): 988 ± 373 |
Nutrition adequacy of <82% vs. ≥82% and <81% and ≥81% was associated with a ↓ ICU LOS and ↓ hospital LOS, respectively. |
| Alberda et al.[51] | 2722 MV patients in the ICU for >72 h | Up to 12 days | 1034 ± 514 | Every 1000 kcal/day provided was associated with ↓ 60-day mortality and ↑ VFDs. |
| Faisy et al.[50] | 38 MICU patients MV for at least 7 days | First 14 days of ICU | 704 ± SEM 42 | A mean energy deficit ≥ 1200 kcal per day of MV after ICU Day 14 was associated with ↑ ICU mortality rate. |
| Singh et al.[54] | 93 respiratory ICU patients MV ≥24 h and ICU LOS ≥48 h | Up to ICU discharge | Survivors (n = 57): 1379 (IQR 1279–1563); non-survivors (n = 36): 1109 (IQR 765–1325) | Mean energy adequacy of ≤50% was associated with ↓ survival probability compared to >70–90% and >90% energy adequacy. |
| Strack van Schijndel et al.[52] | 243 MICU/SICU patients enrolled Day 3–5 if expected to be in ICU for another ≥5–7 days | NR, LOV period used for energy and protein balance calculations | Males: 1730 ± 399 Females: 1536 ± 299 |
Achieving both energy and protein goals compared to not achieving both goals was associated with: Males: ↔ hazard ratio for ICU, 28-day and hospital mortality Females: ↓ hazard ratio for ICU, 28-day and hospital mortality |
Articles were identified via Medline (Ovid) search combining “critical* ill* or Intensive Care Unit or ICU” terms with “energy or nutrition delivery”.
Reported in mean ± standard deviation, unless otherwise stated. Values rounded to the nearest whole number.
↑: statistically significant increase in outcome; ↓: statistically significant decrease in outcome; ↔: no significantly statistical difference in outcome.
ARDS: Acute respiratory distress syndrome, EN: Enteral nutrition; ICU: Intensive care unit; IQR: Interquartile range; LOS: Length of stay; LOV: Length of ventilation; MV: Mechanical ventilation; MICU: Medical intensive care unit; NR: Not reported; OR: Odds ratio; SEM: Standard error of the mean; SICU: Surgical intensive care unit; VFDs: Ventilator-free days.