Post‐procedural considerations

Ongoing care

Administration sets should always be changed every 24 hours (Loveday et al. [91], NICE [119], O'Grady et al. [132]). Existing injection sites on the administration set should never be used to give additional medications as parenteral nutrition is incompatible with numerous medications. Drugs may bind to the nutrients or the parenteral nutrition bag, reducing their availability. If any additional medications, blood products or central venous pressure (CVP) readings are required then they should be given or taken via a separate lumen or via an alternative device (NCEPOD [110]).
A volumetric infusion pump must be used to ensure accurate delivery of parenteral nutrition. No bag should be used for longer than 24 hours (BNF [23]).
If the infusion must be discontinued, the catheter should be flushed to maintain patency. The risk of infection increases if the infusion is disconnected from the central venous device; therefore, it is not advisable to disconnect parenteral nutrition until the whole daily requirement has been administered (NCEPOD [110]).
During intravenous feeding, monitoring is necessary to detect and minimize complications. Once feeding is established and the patient is biochemically stable then the frequency of monitoring may be reduced if the clinical condition of the patient permits (Table 8.19).
Table 8.19  Monitoring in nutrition support
ParameterFrequency of monitoringRationaleInterpretation
Catheter entry siteDailySigns of infection or inflammationInterpret with knowledge of infection control
Skin over insertion site and tip of cannula or midline catheterDailySigns of thrombophlebitis 
General conditionDailyTo check tolerance of feed and that feed and route continue to be appropriate 
Temperature/blood pressureDaily, then as neededSign of infection, fluid balance 
Sodium, potassium, urea, creatinineBaseline, then daily until stable, then one or two times a weekAssessment of renal function, fluid statusInterpret with knowledge of fluid balance and medication; urinary sodium may be helpful in complex cases with gastrointestinal fluid loss
GlucoseBaseline, then one or two times daily until stable (more if needed), then weeklyGlucose intolerance is commonGood glycaemic control is necessary
Magnesium, phosphateBaseline, then daily if risk of refeeding syndrome, then three times a week until stable, then weeklyDepletion is common and under‐recognizedLow concentrations indicate poor status
Liver function testsBaseline, then twice weekly until stable, then weeklyAbnormalities common during PNComplex; may be due to sepsis, other disease or nutritional intake
Calcium, albuminBaseline, then weeklyLow or high levels may occurCorrect measured serum calcium concentration for albumin; hypocalcaemia may be secondary to magnesium deficiency; low albumin reflects disease, not protein status
C‐reactive proteinBaseline, then two or three times a week until stableAssists interpretation of protein, trace element and vitamin resultsTo assess the presence of an acute‐phase reaction; the trend of results is important
Zinc, copperBaseline, then every 2–4 weeks depending on resultsDeficiency is common, especially with increased lossesPatients are most at risk when anabolic zinc decreases and copper increases in acute‐phase reaction
SeleniumBaseline if risk of depletion, further testing depending on thisDeficiency is likely in severe illness and sepsis, and in long‐term nutrition supportDecreases in acute‐phase reaction; long‐term status better assessed by glutathione peroxidase
Full blood countBaseline, then one or two times a week until stable, then weeklyAnaemia due to iron or folate deficiency is commonEffects of sepsis may be important
Iron, ferritinBaseline, then every 3–6 monthsIron deficiency is common in long‐term PNIron status is difficult to assess in acute‐phase reaction; iron decreases while ferritin increases
Folate, vitamin B12Baseline then every 2–4 weeksIron deficiency is commonSerum folate/B12 sufficient with full blood count
ManganeseEvery 3–6 months if on home PNExcess provision to be avoided, more likely in liver diseaseRed blood cell or whole blood better measure of excess than plasma
Vitamin DSix‐monthly if on long‐term PNLow levels if houseboundRequires normal kidney function for effect
Bone densitometryOn starting home PN, then every 2 yearsDiagnosis of metabolic bone diseaseTogether with lab tests for metabolic bone disease
PN, parenteral nutrition.
Source: Adapted from NCCAC ([108]) with permission of NICE.

Home parenteral nutrition

There are a few indications for home parenteral nutrition. It may be necessary in patients who have complete intestinal failure or insufficient bowel function to maintain an adequate nutritional status via the enteral route, for example short bowel syndrome due to Crohn's disease or a high‐output fistula. It may also be required if it is not possible to access the gastrointestinal tract, although all possible enteral routes should be explored.
This is a complicated and specialist treatment, requiring 24‐hour access to advice and support, and should be co‐ordinated through a specialist intestinal failure centre.
No patient should be considered for home parenteral nutrition without a multidisciplinary discussion with the patient and the formulation of a clear management plan. If continuation of hospital‐initiated parenteral nutrition is considered essential, the implications must be discussed with the multiprofessional team, including the medical consultant, dietetics, pharmacy, intravenous therapy team, complex discharge co‐ordinator and patient (BAPEN [12]).
Patients require an extensive period of specialized training to manage parenteral nutrition in the home environment. This should only be undertaken by specialist intestinal failure units or home parenteral nutrition (HPN) designated units with a multidisciplinary nutrition support team with the appropriate expertise (BAPEN [12]).
It is important that all members of the multidisciplinary team, including the dietician, nurse, doctor, pharmacist and community services, are involved in the patient's nutritional care to ensure a thorough and co‐ordinated approach to nutritional management.

Termination of parenteral nutrition

Parenteral nutrition should not be terminated until oral or enteral tube feeding is well established (NICE [123]). Parenteral nutrition may require weaning at a reduced rate if there is concern about rebound hypoglycaemia or management of concurrent insulin, as well as to ensure adequate nutritional intake via an alternative route. It is important that all members of the multidisciplinary team are involved in the decision to terminate parenteral nutrition and that enteral intake is monitored sufficiently.