Extremely well tolerated Feeding shock
FEEDING DURING CIRCULATORY FAILURE Dr S Omar Chris Hani Baragwanath Hospital Hospital/University of Witwatersrand
Introduction Circulatory shock lack of adequate tissue perfusion to ensure appropriate nutrient and 0 2 supply for normal cellular function. Some treatment may be specific and others, like nutrition -universal. Meta-analysis indicated that early enteral feeding in critically ill patients may reduce mortality. Guidelines recommend hemodynamically stable patients be fed early (24-48h)- functional gut Doig et al. ICM 2009; 35 Kreymann et al. Clinical Nutrition 2006; 25
What about the shocked patient? The GIT is called the motor of MOD during shock states Uncertainty around early feeding in shock: Safety Timing Form
Understanding the risk GIT blood flow is from Celiac/SMA/IMA Small branches enter bowel wall Arterioles enter submucosa Branch to Villi
P0 2 Low P0 2 at tip 20-25% of CO V0 2 high (30%) Susceptibility to hypoxia due to vasoconstriction
But.. Splanchnic blood flow increases after meals More so with fats than CHO Enteral feeds also increase mucosal 0 2 needs Increase CO Redistribution of flow This hyperemic response Cresci et al. Nutrition in Clinical practice. 2008;23
Rat model Enteral formula Controlled hypotension Protected against liver ischemia Endotoxic shock - Benefit not seen Human studies 9 post op cardiac on Dob/NE Enteral feeding increased SV and (at the expense of MAP - SVR) Nutrient absorption increased No pressor change needed McClave et al. Nutrition in Clinical Practice 2003;18
Case series of 4 burns patients Enterally fed during hypotension motility and absorption Abdominal distension Continuous enteral feeding Massive distension At surgical exploration 2 limited bowel ischemia 2 no ischemia McClave et al. Nutrition in Clinical Practice 2003;18
Recent clinical data Khalid et al. early enteral nutrition and outcomes of critically ill patients treated with vasopressors and mechanical ventilation. AJCC. 2010;19
Effect of early enteral nutrition on outcome of critically ill with hemodynamic instability Retrospective analysis of multi-institutional database Primary outcome ICU and Hospital mortality Included: Non surgical ICU admissions MV>48h H/D unstable requiring 1 vasopressors within 1 st 2 d of MV To account for the non randomisation confounder adjustments carried out and propensity score matching for residual bias
Unadjusted mortality <48h 48h
After propensity matching
Early feeding was associated with 34% decreased risk of death
Study conclusion Early enteral feeding in MV hemodynamically unstable patients is associated with reduced mortality Benefit greater in sicker patients, multiple vasopressors No evidence of harm
Mancl et al. Tolerability and safety on enteral nutrition in critically ill patients receiving intravenous vasopressor therapy.2013 JPEN;37
Retrospective database review academic medical center 126 ICU beds Included: Adults Enteral tube feeding Vasopressors 1 patient could have multiple episodes Concomitant episode 24h
Data collected: Vasopressors Type of shock EN- type/rate/caloric density Gastric residuals Promotility / opiods/ NMB etc Emesis/Stools Serial lactate Imaging CT and Abd Xray
1 - EN tolerance No emesis No Gastric residuals 300ml No positive findings on imaging No bowel ischemia/perforation 2 Outcomes Rates of adverse events Vasopressor dosages Mortality
Overall Tolerated Not tolerated
What remained significant: Hours of overlap Mean delivered calories Max dose of NE equivalent Absence of a prokinetic
% tolerance by NE equivalent dose Adrenaline (ug/kg/min : 0.18 0.21 0.25
Mortality data Of 259 patients 64.5% survival at discharge No mortality difference between EN tolerability or no tolerability 2/92 deaths were known to have bowel perforation/ischemia Concomitant EN and vasopressor may have contributed
Reignier et al. Impact of early nutrition and feeding route on outcomes of mechanically ventilated patients with shock: a post hoc marginal structural model study. ICM 2015;41
Observational study Adult MV >72h Shock (SBP<90) within 48h of MV No abdominal surgery within past month Nutrition timing - <48h vs 48h Feeding route PN vs EN (EN or EN +PN) for 1 st 3 days
Early EN and Mortality/ VAP After adjustment for confounders on multivariate analysis VAP risk decreased after D7 upto D28, except in renal failure and liver failure
D2 and D3 delivered calories: 20 vs < 20 kcal/kg/d HR(95% CI) P value D28 mortality 0.96 (0.83-1.12) 0.63 VAP risk by D28 0.9 (0.8-1.01) 0.08 Multivariate analysis
Feeding route (EN vs PN) and Mortality/VAP EN+PN vs PN mortality EN only vs PN mortality For Renal failure Liver failure EN+PN vs PN HR (95% CI) P value 1.07 (0.95-1.20) 0.27 1.18(0.98-1.44) 0.08 1.43 (1.23-1.67) 1.68 (1.34-2.10) <0.001 <0.001 Multivariate analysis
Study conclusion ICU patients with shock on MV benefit from early nutrition (<48h) Route is no different Caloric intake (< or > 20kcal/kg/d) is no different
Summary of feeding in shock based on data presented Bowel ischemia is rare (<1%) but must be anticipated Early EN means-24-48h Early enteral nutrition is likely to be safe and may be associated with mortality benefit The sicker patients the greater the benefit from early EN The dose and type of vasopressor is important to bear in mind There appears to be no difference in the route of early feeding Patients with Renal and Liver failure may benefit from early PN
Some answers, and definitely more questions