Feeding the Hemodynamically Unstable Adult Patient
VBMC TRAUMA CARE SERVICES GUIDELINE
Feeding
the Hemodynamically Unstable Adult Patient
Summary and Background
The gastrointestinal (GI) tract plays an important role in regulating the
body’s inflammatory response and immune function, in addition to the absorption
of nutrients. In critical illness, patients can experience a massive
pro-inflammatory response from the gut, leading to oxidative tissue damage,
apoptosis, and an impaired immune response towards infectious pathogens.
Additionally, increased mucosal permeability can occur, increasing the risk of
infection via bacterial translocation into the bloodstream. 30-50% of ICU
patients are malnourished upon admission, a factor that can further predispose
patients to these consequences of GI impairment.
Early initiation of enteral nutrition (EN) can be greatly beneficial in
supporting proper GI function in critically ill patients. Providing as little
as 20% of a patient’s total nutritional goals enterally can lower inflammation,
reduce oxidative stress, support the humoral immune response, restore
microbiome composition, and decrease insulin resistance. The 2016 ASPEN/SCCM
guidelines state, “In setting of hemodynamic compromise or instability, EN
should be withheld until patient is fully resuscitated and/or stable,” due to
the risk of nonocclusive bowel necrosis (NOBN). The largest study supporting
the concern for NOBN stems is the NUTRIREA-2 study that investigated 2410
mechanically ventilated patients requiring vasopressor support, randomized to
early enteral nutrition or parenteral nutrition. Patients in the enteral
nutrition group experienced increased bowel ischemia over the parenteral
nutrition group. Of note, the study’s patient population had an elevated mean
vasopressor requirement of 0.53 ug/mg/min of norepinephrine.
The effect of vasopressors on gut perfusion and the risk of NOBN seems to
be dose related. Thus, recommendations for a safe dose range and vasopressor
selection for initiation of enteral nutrition would be of utility. These
guidelines seek to increase the administration of early enteral nutrition in
appropriate clinical scenarios, as well as provide guidance in higher-risk
situations where enteral nutrition should be restricted to a reduced rate or
withheld.
Prior to initiation of EN, assess
patient for resuscitation and hemodynamic stability markers:
-Lactate
normalized (≤ 2.0) or correcting rapidly
-Mean
arterial pressure (MAP) maintained >65 (with or without vasopressors)
-Vasopressor
requirements decreasing or stable (e.g.: Norepi @ 0.2mcg/kg/min with other
stable parameters listed here)
-Fluid requirements stabilizing (patient is not actively requiring
boluses for blood pressure maintenance)
-No ongoing or active
bleeding
-The primary team will initiate the
tube feeding based on resuscitation and hemodynamic stability markers and using
the guidelines below (Table 1)
-The RD will be responsible for
completing a Nutrition Evaluation note with tube feeding recommendations within
24 hr of the placement of the Nutrition Consult order
References
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