Vasopressors and Nutrition Therapy: Safe Dose for the Outset of Enteral Nutrition?

Table 1

Included articles and their main findings.

Author, year	Objective	Most common symptoms of EN intolerance (%)	Vasopressor drug used	Dose used	Mesenteric ischemia reported (%)	Main results
Reignier et al.	To investigate whether early ENT had beneficial clinical effects compared with early PN in patients requiring invasive mechanical ventilation and vasopressor support for shock	Vomiting (34%) and diarrhea (36%)	Adrenaline; Dobutamine; Noradrenaline	NR	Yes (2%)	In critically ill adults with shock, early isocaloric enteral nutrition did not reduce mortality or the risk of secondary infections but was associated with a greater risk of digestive complications compared with early isocaloric parenteral nutrition
Merchan et al.	To evaluate the tolerability of ENT in patients with septic shock who require vasopressor support and determine factors associated with tolerance of ENT	Gastric residuals >250 mL (74%)	Norepinephrine-equivalent	≤0.14 μg/kg/min	No	Early EN may be tolerated and safely administered in patients with septic shock who are adequately fluid resuscitated and receive doses of <0.14 mg/kg/min of norepinephrine
Bruns et al.	To discuss the safe initiation of ENT concomitant with the use of vasopressors	NR	Norepinephrine; Epinephrine; Dobutamine; Phenylephrine	NR	NR	Most postoperative patients requiring vasopressor therapy can likely be safely initiated and advanced on ENT. Administration of nutrition early in the course of critical illness is associated with improved outcomes and should be a primary goal in the treatment of these patients
Brisard et al.	To assess the hypothesis that early first-line ENT, as compared to early first-line PN, decreases day 28 all-cause mortality in patients receiving IMV and vasoactive drugs for shock	NR	Epinephrine; Dobutamine; Norepinephrine	NR	NR	In progress
Marik et al.	To provide an evidence-base assessment of factors leading to inadequate enteral nutrition support in critically ill patients	NR	NR	NR	NR	The benefits of early EN were greatest in the sickest patients and those receiving multiple vasopressor
Yang et al.	To summarize the effect of ENT and vasoactive agents on gastrointestinal blood flow and perfusion in critically ill patients, based on evidence	NR	NR	NR	NR	Current knowledge of EEN in critically ill patients with hemodynamic instability is still incomplete
Mancl et al.	To evaluate the tolerability and safety of ENT in critically ill patients receiving intravenous (IV) vasopressor therapy	Rising serum lactate (30.6%), elevated gastric residuals (14.5%), emesis (9.0%)	Norepinephrine	<12.5 μg/min	Yes (0.9%)	EN is relatively well tolerated in patients receiving IV vasopressor support equivalent to 12.5 mcg/min of norepinephrine or less. Tolerability was less likely in patients receiving higher doses of IV vasopressors and in those receiving dopamine or vasopressin
Allen et al.	To review the effects of vasoactive substances such as pressors and inotropes on the gastrointestinal tract, as well as their use in combination with ENT	NR	Dopamine	3–10 μg/g/kg/min	NR	The use of vasoactive substances should not entirely preclude clinicians from using the enteral route to supply nutrition. The evidence suggests that EN may be safely delivered to patients requiring vasoactive substances for hemodynamic support
			Dobutamine	12 μg/kg/min or 200–800 mcg/min
			Norepinephrine	6–25 mcg/min
			Epinephrine	Doses not related to conclusion
			Phenylephrine
			Vasopressin
Wells et al.	To review the effects of vasopressors on gastrointestinal blood flow, discuss complications associated with vasopressor use during ENT, and propose important considerations to determine the safety of ENT in hemodynamically unstable patients requiring vasopressor support	2 consecutive gastric aspirate volume (GAV) measurements between 150 and 500 mL, 1 GAV measurement	Dopamine	<5 μg/kg/min	No	In the majority of ICU patients, administration of EN into the stomach during the provision of low, stable doses of pressors with close monitoring for signs of intolerance or worsening hemodynamic stability poses very little risk for bowel necrosis
			Epinephrine	0.3 μg/kg/min
			Norepinephrine	0.9 μg/kg/min
			Phenylephrine	0.5 μg/kg/min
			Vasopressin	—
Khalid et al.	To determine the effect of early enteral feeding on the outcome of critically ill medical patients whose hemodynamic condition is unstable	NR	Norepinephrine, epinephrine, dopamine, or phenylephrine	NR	No	Early enteral nutrition may be associated with reduced intensive care unit and hospital mortality in patients whose hemodynamic condition is unstable