I have recently finished a four month rotation in ITU which taught me many things, how to put a central line in, how to walk into a cardiac arrest and properly take control of someone’s airway and how to put an NG into a ventilated patient (sometimes with great difficulty).
As soon as patients arrived on our unit we thought about feeding them, within hours of admission suitable patients were started on a NG feeding rota. During the twice daily reviews we would look at how much aspirated was coming back from the NG and was this patient absorbing their feed. And twice daily in the notes the FLATHUG was documented – F for feeding and fluids. When patients weren’t absorbing feed or couldn’t be fed by this route we would get the nutrition team involved very quickly for the inevitable discussion – should we start this patient on parenteral nutrition and when should we do this?
Casaer et al carried out a randomised control trial in seven different intensive care units to address the question of when we should be starting parenteral nutrition in critically ill adult patients. Over 4,000 patients we recruited into this trial and all had a nutritional risk screening score of 3 or more (therefore all patients were deemed nutritionally at risk). Patients were randomised into two groups, early or late parenteral. All patients who were unable to eat by day 2 of their ITU admission received enteral nutrition, however if they failed to meet their nutritional target the group in the early parenteral treatment arm started to receive this within 48 hours.
Those in the late group however did not receive any parenteral nutrition until their 8th ITU day. In both groups continuous insulin infusions were used to maintain normoglycaemia.
The primary endpoint was the duration of dependency on intensive care, i.e. the number of days spent on intensive care and the time to discharge from intensive care. Secondary endpoints included new infections, duration of antibiotic therapy, time to final weaning from mechanical ventilators support and the rate of acute kidney injury.
The results were very interesting. The median ITU stay was 1 day shorter in the late-initiation group compared to the early-initiation group, a relative increase in 6.3% in the likelihood of early discharge alive from ITU (hazard ratio 1.06′ 95% CI 1.00 to 1.13 p=0.04).
With regards to secondary outcomes fewer patients in the late initiation group acquired a new infection during their intensive care stay and the duration of renal-replacement therapy and mechanical ventilation were shorter in the late initiation group (see paper for details and for the full list of secondary outcomes.
The author’s conclusions:
In conclusion, the early initiation of parenteral nutrition to supplement insufficient enteral nutrition during the first week after ICU admission in severely ill patients at risk for malnutrition appears to be inferior to the strategy of withholding parenteral nutrition until day 8 while providing vitamins, trace elements, and minerals. Late parenteral nutrition was associated with fewer infections, enhanced recovery, and lower health care costs.
I look forward to discussing this paper at 8pm BST on Sunday and discussion points for this will be posted shortly