The CALORIES trial (UK) compared parenteral nutrition (PN) versus enteral nutrition (EN) initiated via the nasogastric route in ICU patients unable to receive oral feeding. What was its primary conclusion?

• A PN was superior to EN with significantly lower 30-day mortality
• B EN was superior to PN with lower 30-day mortality and significantly fewer infections
• C Early PN (within 24 hours) led to less gut atrophy than EN
• D EN and PN had equivalent 30-day mortality; EN was associated with more hypoglycemia, PN with more infections ✓

Explanation

The CALORIES trial (Harvey et al., NEJM 2014) randomized 2400 ICU patients to early EN versus early PN within 36 hours. The primary outcome (30-day all-cause mortality) was similar: 33.1% EN vs 34.2% PN (not significant). EN was associated with significantly more episodes of hypoglycemia; PN was associated with more infections (though this was secondary). This landmark trial challenged the dogma that EN is always superior to PN in critically ill patients. Current ESPEN guidelines recommend EN as the preferred route but acknowledge that PN should be initiated when EN is insufficient or contraindicated, rather than allowing significant caloric debt.

Reference: Bailey & Love's Short Practice of Surgery, 27th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.