Hyperglycemia is likely to contribute to the negative outcomes associated with TPN in critically ill patients and other hospitalized patients. In surgical patients, hyperglycemia is linked to an increased risk of bloodstream infections (BSI) and sepsis. Patients who receive TPN often develop hyperglycemia because they cannot absorb enough glucose from their intestines to meet their body's needs. The resulting high levels of glucose in the blood stream can increase the risk of developing infections.
In addition to causing hyperglycemia, TPN administration can lead to bacterial overgrowth due to loss of intestinal bacteria. This increases the risk of developing BSI and sepsis. TPN-related BSI are more likely to be caused by gram-negative organisms such as Escherichia coli and Klebsiella pneumoniae. These infections may spread hematogenously to various parts of the body including the lungs, brain, and heart.
TPN use is also linked to an increased risk of developing catheter-associated urinary tract infections (CAUTI). The reason for this link has to do with how TPN tubes function. These tubes are not designed to filter urine; instead, they allow fluid to flow into and out of the patient's body while preventing particles larger than 7 microns from passing through.
The development of hyperglycemia, which occurs in 10–88 percent of hospitalized patients getting TPN therapy, can be linked to the increased risk of problems during TPN therapy, among other variables (4-6). Hyperglycemia is a common problem for any patient receiving intensive care treatment, but it is especially important that health care providers watch patients who are being treated with TPN to prevent these complications from occurring.
Patients who receive TPN often develop hyperglycemia because their body cannot use insulin properly when they are unable to absorb nutrients through their intestines. As a result, they may require higher doses of insulin to control their blood sugar levels. Health care professionals may need to adjust the dose of insulin given via IV or IM injection or put them on a special diet when treating patients with TPN-induced hyperglycemia.
Healthy individuals who receive TPN should have blood tests done regularly to make sure they do not develop complications from the treatment. These tests will help doctors know how well their treatments are working and if they need to change or add anything to the regimen.
Doctors will usually monitor blood glucose levels of patients receiving TPN. If necessary, they can give injections of insulin to lower those levels. Otherwise, they can place patients on a special diet to reduce the amount of food-based sugars entering their bodies while they receive the infusion.
Moore et al. (28) randomly allocated 29 patients to EN and 30 patients to TPN in a trial of nutritional assistance after significant abdominal injuries. The researchers discovered a considerably higher incidence of sepsis among TPN patients. Patients receiving TPN had significantly more infections than those receiving EN.
In conclusion, these findings indicate that the use of TPN is associated with an increased risk of infection. As such, it cannot be recommended for patients who are at risk of developing sepsis.
Source: Can TPN cause sepsis? Published online April 4, 2014.
TPN can lead to the following complications:
TPN is most commonly used for patients with Crohn's disease, cancer, short bowel syndrome, or ischemic bowel disease and can be delivered in the hospital or at home. TPN is also appropriate for severely sick patients who are unable to obtain nourishment orally for more than four days. Finally, TPN is used as a last resort when all other options have been tried.
A patient is a candidate for TPN if he or she is expected to require it for more than seven days. This decision should not be made lightly because the use of TPN has many long-term effects that must be considered. Patients who are candidates for TPN should be referred to a center that specializes in providing this service.
The three main factors that determine how long a patient will need TPN are the type and severity of his or her illness, the age of the patient, and the presence of other health problems. For example, an infant younger than one year old who is diagnosed with gastroenteritis that requires intravenous fluid replacement may be able to recover within seven days and thus would not be a candidate for TPN. An adult in good general health who develops similar symptoms after a severe meal restriction for several days would also be a suitable candidate for TPN.
In addition to determining whether you are a candidate for TPN, your physician will also want to know your opinion on this matter.
TPN is often decreased or stopped before to anesthesia, largely to minimize difficulties caused by high (hyperosmolarity) or fast drop (hypoglycemia) infusion rates in the busy operational arena. However, because sudden cessation might result in severe hypoglycemia, TPN must be progressively reduced. Patients should be made aware of the risk of hypoglycemia and instructed on how to treat it (glucagon, glucose tablets). Once patients are stable on a lower dose for 2-3 days, TPN can be discontinued entirely.
If patient does not receive any glucose for more than 24 hours, he/she will become hypoglycemic and require treatment. The key to prevent this from happening is to continue TPN even after surgery since insulin remains in their body for several days even after stopping the infusion.
In conclusion, TPN administration requires special attention since its interruption or decrease may lead to hyperglycemia or hypoglycemia. Anesthesiologists must be aware of this fact so that they can manage these complications appropriately.
The rate at which TPN is given to a newborn is critical: if given too quickly, there is a danger of fluid overload, which can lead to coagulopathy, liver damage, and reduced pulmonary function as a result of fat overload syndrome. If given too slowly, the TPN will run out before the infant needs it.
Given these concerns, doctors generally do not give TPN faster than 4-6 ml/kg/hr. However, some studies have shown that giving babies TPN at rates as high as 8-10 ml/kg/hr for several days in a row is safe and may be more effective at promoting weight gain. There has been one case report of an infant who received 15 ml/kg/hr for two weeks without any apparent problems. However, most infants will receive TPN for no longer than three days and some for only one day. Therefore, the majority of cases involving TPN at high rates involve only one or two doses rather than a continuous infusion.
When giving TPN at high rates, it is important to monitor the patient for signs of fluid overload such as heavy breathing, flabbiness, blue color of the skin, and rapid heart rate. If these symptoms are noticed, the rate should be slowed down immediately until the effects of the high dose have worn off.