Parenteral nutrition in the ICU

Parenteral nutrition (PN) is a technique of artificial nutrition support, which consists of the intravenous administration of macronutrients, micronutrients, and water. PN has become integrated into intensive care unit (ICU) patient management with the aim of preventing energy deficits and preserving lean body mass. The addition of PN to enteral nutrition is known as supplemental PN. Parenteral feeding should be considered whenever enteral nutritional support is contraindicated, or when enteral nutrition alone is unable to meet energy and nutrient requirements. International guidelines differ considerably regarding the indications for PN. Thus, the ESPEN guidelines recommend initiating PN in critically-ill patients who do not meet caloric goals within 2–3 days of commencing EN, while the Canadian guidelines recommend PN only after extensive attempts to feed with EN have failed. The ASPEN guidelines advocate administering PN after 8 days of attempting EN unsuccessfully. Several studies have demonstrated that parenteral glutamine supplementation may improve outcome, and the ESPEN guidelines give a grade A recommendation to the use of glutamine in critically-ill patients who receive PN. Studies on IV omega-3 fatty acids have yielded promising results in animal models of acute respiratory distress syndrome and proved superior to solutions with omega -6 compositions. The discrepancy between animal models and clinical practice could be related to different time frames.

Enteral nutrition in the ICU

Enteral nutrition (EN) is an integral part of the patient care in the intensive care unit (ICU) in order to maintain gut integrity, to modulate stress and the systemic immune response, and to attenuate disease severity. The timing of commencing EN in critically-ill patients depends on patient status and should be initiated as soon as the patient is stabilized. The energy and protein targets should be estimated and the feed prescription should match the nutritional target. The rate of EN dose increment or the addition of supplemental parenteral nutrition (PN) to reach the nutritional target is still debatable and ranges between 3 days (ESPEN approach) and up to 8 days (ASPEN approach). Micronutrients should be supplemented to all patients. The role of pharmaconutrition is controversial due to recent negative trials, but the use of EN with supplemental omega-3 and GLA for acute respiratory distress syndrome patients is still advocated by ESPEN and ASPEN guidelines.

Damage of Central Catheters in Home Parenteral Nutrition Patients

According to the ESPEN and ASPEN guidelines, in the case of a long-term (>3-month) parenteral nutrition should be administered via a subcutaneous central venous catheter (CVC). There are three types of mechanical complications of tunnelled central catheter: catheter rupture, occlusion by TPN depositing and thrombofibrotic occlusion.was to analyse the incidence of complications central catheter in a group of patients receiving HPN.Between January 2010 and June 2014, HPN was conducted in 584 patients (306 women and 278 men), ninety-nine patients were enrolled in the study: 67 women and 32 men in whom mechanical complications of central catheters were found.Among 99 patients, 71 used the tunnelled Broviac catheter. Groshong catheters were placed only in patients receiving parenteral nutrition due to cancer. Analyses have shown differences between the older and younger in the number of mechanical complications. Younger patients were found to have a larger number of catheter complications (1.6 ± 1.1) in comparison with older patients (1.3 ± 0.7). The catheter that was most commonly damaged was the Broviac catheter 76.8%. The most frequent type of mechanical complications was catheter rupture 64.81%.Mechanical complications of tunnelled central catheters in HPN patients can be repaired in an outpatient setting in half of the cases, which enables continuation of parenteral nutrition without the need to hospitalise the patient. The centres that conduct HPN should offer 24-hour care and help in case of problems with the central venous line to the patients.