Laboratory test | When on PN | When on full enteral feeds |
CBC with RBC indices/differential, reticulocyte count | Every 1 to 3 months or as clinically indicated (More frequent monitoring with blood loss, microcytic anemia, abnormal iron studies, or parenteral iron use) | After PN is discontinued¶, then every 6 to 12 months (More frequent monitoring with blood loss, microcytic anemia, abnormal iron studies, or enteral iron use) |
Iron studies (iron, ferritin, TIBC, transferrin saturation), with CRP* | ||
PN profile:
(May use a comprehensive metabolic panel instead of a PN profile) | When PN is initiated, weekly until stable, and then with significant changes in PN formulation or volume For patients on stable PN, these labs should be monitored every 1 to 3 months | After PN is discontinued¶, then every 6 to 8 months, depending on clinical status |
Hepatic panel:
| When PN is initiated, then weekly until stable For patients on stable PN, monitor every 1 to 3 months | Annually for patients with history of IFALD |
Copper, zinc, selenium (measure in conjunction with CRP) | Measure 30 days after PN initiation, then every 6 months (If level is low, or if making changes to dosing of these trace minerals in PN, repeat every 2 to 3 months. Monitor more frequently in patients with persistent neutropenia or anemia) Measure copper and ceruloplasmin with CRP and CBC in patients with signs of copper deficiencyΔ | Measure zinc after PN is discontinued¶, then at least annually Measure copper and ceruloplasmin with CRP in patients with signs of copper deficiencyΔ |
PT, INR (as an index of vitamin K sufficiency)◊ | Every 6 months (Monitor more frequently in patients with gastrointestinal bleeding, bacterial overgrowth, or cholestasis) | After PN is discontinued¶, then at least annually (Monitor more frequently in patients with gastrointestinal bleeding, bacterial overgrowth, or cholestasis) |
Monitor fat-soluble vitamin status:
| Annually (Check every 3 to 6 months in patients with evidence of deficiency, on enteral supplementation, or with chronic liver disease or cholestasis) | After PN is discontinued¶, then at least annually (Check every 3 to 6 months in patients with evidence of deficiency, those on enteral supplementation, or those with chronic liver disease or cholestasis) |
Serum vitamin B12 | Annually | After PN is discontinued¶, then every 6 to 12 months, especially in patients who had resection of the distal ileum or persistent macrocytic anemia§ |
Essential fatty acid panel | Measure every 3 to 6 months in patients on lipid restriction (ie, total fat intake ≤1 g/kg/day for >10 to 14 days) | Measure if there are clinical signs of essential fatty acid deficiency such as poor growth or rash |
Aluminum, carnitine profile | Measure 30 days after PN initiation, then every 6 months | Not necessary |
Alpha-fetoprotein level | Annually for patients with a history of cirrhosis related to IFALD | Annually for patients with history of cirrhosis related to IFALD |
Chromium, manganese | Annually (Measure more frequently in patients with poor glycemic control [which may be caused by chromium deficiency]) | Generally not necessary |
Urine sodium | Consider every 6 months or more frequently in patients with poor weight gain, those with high ostomy output, or those on enteral NaCl supplementation | Consider every 6 months or more frequently in patients with poor weight gain, those with high ostomy output, or those on enteral NaCl supplementation |
PN: parenteral nutrition; CBC: complete blood count; RBC: red blood cell; TIBC: total iron-binding capacity; CRP: C-reactive protein; BUN: blood urea nitrogen; AST: aspartate aminotransferase; ALT: alanine aminotransferase; GGTP: gamma-glutamyl transpeptidase; IFALD: intestinal failure-associated liver disease; PT: prothrombin time; INR: international normalized ratio; NaCl: sodium chloride; MMA: methylmalonic acid.
* Serum ferritin is an index of iron stores but is also increased in the setting of inflammation. Measurement of CRP concurrently with iron studies helps to determine if an acute phase response is present and permits accurate interpretation of the results. An acute phase response also tends to increase serum concentrations of copper and decrease serum concentrations of zinc.
¶ Measure vitamin and mineral/trace element levels 4 to 8 weeks after PN is discontinued and then a second time 4 to 6 months after PN is discontinued.
Δ Signs of copper deficiency include a microcytic anemia unresponsive to iron intake, neutropenia, or osteopenia.
◊ For patients with elevated PT/INR, measurement of PIVKA-II is helpful to assess for vitamin K deficiency.
§ Vitamin B12 levels should be monitored particularly closely in patients who have had the distal ileum resected and are on partial or full enteral feeds. Concentrations of MMA also reflect vitamin B12 deficiency, and measurements of MMA in urine or serum may be useful for patients with abnormal vitamin B12 levels, those with distal ileal resection, or those on treatment for vitamin B12 deficiency.Do you want to add Medilib to your home screen?