Fluids, Electrolytes, Acid-Base Disorders, and Nutrition Support

vii.

It is common clinical practice to withhold copper and manganese in the PN formulation

for patients with hepatobiliary/cholestatic liver disease or a direct (conjugated) bilirubin

concentration greater than 2 mg/dL. With this practice, the multitrace elements (MTE) product

is omitted from the PN solution, and zinc and selenium are added separately. However, with

the MTE product reformulation in 2020, which substantially reduced the dose of copper

and manganese, and the growing body of literature describing micronutrient deficiencies

in critically ill patients, it is unclear whether this practice is warranted for all patients with

hyperbilirubinemia (refer to previous section on copper for more information).

viii.

Some clinicians withhold selenium for patients with significant renal disease who do not

receive hemodialysis or CRRT, though data in support of this practice are lacking. This can be

accomplished by providing the desired trace element ingredients individually.

Shortages of PN ingredients

Numerous global and national events have resulted in critical shortages of almost every PN

ingredient over the last several decades. This has led to errors and substandard practice for PN

management (JPEN J Parenter Enteral Nutr 2012;36:44S-7S).

ii.

Considerations for management of PN shortages are published by ASPEN and should be

referenced during times of shortages (www.nutritioncare.org/ProductShortages/).

Should supplemental PN (SPN) be administered to patients intolerant of EN:

Casaer/EPaNIC study (N Engl J Med. 2011;365:506-517) of mostly surgical patients, randomized

controlled trial: EN only for 7 days; then PN initiated (hypertonic dextrose solutions for 2 days;

then PN) versus SPN in addition to whatever patients receiving EN could tolerate during the first

7 days

Worsened survival expressed as discharged alive from the ICU within 8 days (72% vs 75%),

more infections (26% vs 23%), ICU length of stay greater than 3 days (51% vs 48%) with early

SPN

ii.

The patient population was limited because patients who were malnourished (BMI less than 17

kg/m2) were excluded. In addition, about 60% of the population were cardiac surgery patients,

for whom the indication for PN is questionable; 50% of patients were extubated by ICU day

2; and 70% of patients had an ICU length of stay of only 3 or 4 days (which would imply a

questionable severity of critical illness). Finally, only 58% of patients in the early PN group

were even administered PN (for 1 or 2 days), and only 25% patients in the late PN group ever

received PN.

controlled trial: Patients who received less than 60% target from EN by day 3 with an anticipated

ICU stay greater than 5 days received SPN or EN alone. SPN was discontinued by day 8.

SPN group had decreased infections (27% vs 38%).

ii.

Smaller study than the Casaer study. Not all patients had REE measured (some were predicted

REE). Protein target was only 1.2 g/kg/d. No difference in ICU/hospital length of stay, mortality

ASPEN (2022) (JPEN J Parenter Enteral Nutr. 2022;46:12-41). For adult critically ill patients

receiving EN, it is recommended that SPN not be initiated before day 7 of ICU admission. This

is a departure from the 2016 guidelines, which suggested initiation of SPN after 7 to 10 days if

patients were unable to meet at least 60% of energy and energy requirements (JPEN J Parenter

Enteral Nutr. 2016;40:159-211). Of note, the studies evaluated in the 2022 guidelines did not include

patients with malnutrition.

categorized as high nutrition risk (according to NRS-2002) with poor tolerance to EN after major

abdominal surgery. Early SPN (day 3; E-SPN) was compared with late SPN (day 8; L-SPN).

Increased energy delivery and fewer nosocomial infections were observed in patients in the E-SPN

group with no differences in other complications. Application to clinical practice may be limited

by the homogeneity of study patients (primarily male, Chinese), who were relatively healthy (most