Higher Calorie Delivery, Increased Gastric Residual Volume in Critical Illness

Nurse filling a bottle of enteral nutrition, Palliative Care, Conceptual Image, horizontal composition
Researchers examined the relationship between enteral calorie delivery and gastrointestinal dysfunction in adults who are critically ill.

Higher calorie delivery with enteral nutrition is associated with increased rates of gastric residual volume (GRV) and prokinetic administration, but not diarrhea, abdominal distension, or vomiting or regurgitation among patients with critical illness, according to a study in Clinical Nutrition.

Researchers conducted a systematic review and meta-analysis to assess the relationship between enteral calorie delivery and specific gastrointestinal (GI) dysfunction outcomes in critical illness.

Researchers searched for relevant randomized controlled trials (RCTs) in the MEDLINE, EMCARE, EMBASE, and CINAHL databases from January 1, 2000, to August 11, 2021. Eligible studies were parallel group RCTs with adult patients with critical illness (aged ≥16 years); enteral nutrition (EN) delivered for at least 2 days, with a difference in calorie delivery between higher and lower calorie groups; and any outcome related to GI dysfunction.

The primary outcome was the incidence of a large GRV (≥300 mL).

The analysis included 13 studies with 6824 patients — 3402 in the higher calorie group and 3422 in the lower calorie group. The study interventions were hypocaloric EN (n=7), energy-dense EN (n=2), delayed EN (n=2), fat-modified EN (n=1), and intermittent EN (n=1).

The higher calorie group had a mean calorie delivery of 1673±468 kcal/d compared with 1121±312 kcal/d in the lower calorie group. The unweighted pooled mean difference was 552 (95% CI, 572-532) kcal/d (P <.0001).

A total of 5 studies reported the number of patients with a GRV of at least 300 mL (n=4478 total patients). Higher calorie delivery significantly increased the risk of having a GRV greater than or equal to 300 mL (risk ratio [RR], 1.40; 95% CI, 1.09-1.80; P =.009), with no evidence of heterogeneity (I2=17%; P =.31).

A total of 739 patients across 8 studies reported vomiting or regurgitation. Higher calorie delivery was not associated with vomiting or regurgitation (RR, 0.93; 95% CI, 0.58-1.49; P =.76), with no evidence of heterogeneity (I2=32%; P =.17).

A total of 2029 patients across 4 studies reported receiving prokinetics. Higher calorie delivery was associated with increased administration of prokinetics (RR, 1.18; 95% CI, 1.11-1.27; P <.001), with no evidence of heterogeneity (I2=0%; P =.69).

A total of 80 patients across 4 studies reported abdominal distension. Higher calorie delivery did not affect the incidence of abdominal distension (RR, 0.71; 95% CI, 0.49-1.04; P =.08), with no evidence of heterogeneity (I2=0%; P =.47).

A total of 5150 patients across 6 studies reported diarrhea. Higher calorie delivery had no effect on diarrhea (RR, 1.12; 95% CI, 0.93-1.35; P =.22), with no evidence of heterogeneity (I2=36%; P =.17).

Study limitations include using strategies for dichotomizing calorie delivery that may have different effects on measures of GI dysfunction and limited synthesis due to using diverse and nonstandardized definitions of GI dysfunction.

“The routine use of strategies aimed at delivering greater calorie doses, such as calorie-dense enteral formulae, should be carefully considered in clinical practice balancing any perceived benefit of augmented energy delivery with potential harm,” the study authors noted.

Reference

Murthy TA, Plummer MP, Tan E, Chapman MJ, Chapple LS. Higher versus lower enteral calorie delivery and gastrointestinal dysfunction in critical illness: a systematic review and meta-analysis. Clin Nutr. 2022;41(10):2185-2194. doi:10.1016/j.clnu.2022.08.011