What Does TPN Look Like?
Here is a bag of Charlie's TPN
The contents of the TPN solution are determined based on the age, weight, height, and the medical condition of the individual. All solutions contain sugar (dextrose) for energy and protein (amino acids). Fats (lipids) may also be added to the solution. Electrolytes such as potassium, sodium, calcium, magnesium, chloride, and phosphate are also included, as these are essential to the normal functioning of the body. Trace elements such as zinc, copper, manganese and chromium are also needed. Vitamins can be included in the TPN solution, and insulin, a hormone that helps the body use sugar, may need to be added. The TPN Central Line is used only for nutrients; medications are not added to the solution, If Charlie was to require IV medication would be given via a separate lumen.
The TPN solution is infused slowly at first to prevent fluid imbalances, then the rate is gradually increased. The infusion time varies between 12-24hrs. For Charlie he is currently on 16hrs, this includes a 3 hour ramp down towards the end to prevent his blood sugars from plummeting.
On a weekly basis Charlie has his bloods taken to monitor his hydration status, renal function, risk of re-feeding syndrome, and both electrolyte deficiencies and excesses. Responding appropriately to this, in turn, will help to minimise the risk of complications. Electrolytes (Sodium, Potassium & Magnesium), bone profile (Calcium & Phosphate), infection markers (such as C Reactive Protein and white blood cells) and liver function tests are also taken.
Initially Charlie's Cholesterol and triglycerides were reviewed weekly and then they were reduced to 3 monthly once he was stable and no longer at risk of hyperlipidaemia. Trace elements (zinc, copper, selenium and manganese) and vitamins (A, D, E, B12, Folate) are also checked at baseline if there is evidence of malnutrition then this should be repeated 3 monthly. Charlie's urinary electrolytes (sodium and potassium) is also monitored, I take in samples of his urine pre & post TPN along to his 3 monthly clinic reviews.