Incidence of vein thrombosis in peripheral intravenous nutrition: effect of fat emulsions

Peripheral parenteral nutrition in surgery - a systematic review and meta-analysis

BACKGROUND

Peripheral parenteral nutrition (PPN) refers to the delivery of artificial nutrition via a peripheral intravenous cannula. As a nutritional intervention it remains under-utilised in peri-operative care. This is despite purported advantages which includes avoiding the risks associated with central venous lines and preventing potential delays to the initiation of nutrition support. This systematic review and meta-analysis will detail the available evidence for PPN use in surgery.

METHODS

A comprehensive search of the EMBASE and Medline databases was undertaken to identify randomised control trials (RCTs) involving PPN use in surgical patients published until July 30th 2022. Three domains of PPN use were reviewed including: PPN compared to crystalloid intravenous fluids on nutritional and clinical outcomes; PPN compared to Central PN (CPN) on nutritional outcomes and complications; and strategies to prevent thrombophlebitis associated with PPN.

RESULTS

The meta-analysis included 8 studies which included 698 patients. Use of PPN led to reduced post-operative weight loss (% body weight change) with a mean difference of -1.45% (95% CI -2.9 to -0.01, p = 0.05). There was no statistically significant difference in terms of length of stay, infectious/non-infectious complications, surgical site infections or phlebitis. 42 RCTs were included in the systematic review. 14 RCTs compared PPN to crystalloid infusion. There was significant heterogeneity in the trial populations, interventions and measured outcomes. Most trials found that PPN may improve nitrogen balance and positively impact nutritional markers. Quality of life and post-operative complications were either improved or no difference found in trials assessing these outcomes. Four RCTs showed that PPN is a safe and feasible alternative to CPN. 22 RCTs reported on measures that may impact on thrombophlebitis rates associated with PPN. These included lower osmolality of PPN solution, cyclical PPN delivery, use of a small gauge polyurethane cannula in an upper limb vein, addition of heparin/hydrocortisone to PPN solutions and placement of a GTN patch over infusion sites.

CONCLUSION

PPN is a safe and effective mode of delivery of peri-operative nutrition. It is a feasible short-term alternative to central-line delivered PN. There are a number of strategies to reduce thrombophlebitis associated with PPN use. Further high-quality RCTs are required to assess the use of PPN in contemporary surgical practice.

New Parenteral Lipid Emulsions for Clinical Use

Routine use of parenteral lipid emulsions (LE) in clinical practice began in 1961, with the development of soybean oil (SO) - based LE. Although clinically safe, experimental reports indicated that SO-based LE could exert a negative influence on immunological functions. Those findings were related to its absolute and relative excess of omega-6 polyunsaturated fatty acids (PUFA) and the low amount of omega-3 PUFA and also to its high PUFA content with an increased peroxidation risk. This motivated the development of new LE basically designed along the reduction of omega-6 PUFA and the omega-3 PUFA addition in order to obtain balanced levels of the omega-6/omega-3 ratio. The new LE for clinical use (available in Europe and South America) are differentiated by their content in polyunsaturated (omega-6 and omega-3), monounsaturated, and saturated fatty acids (FA), as well as FA source of their origin, including soy, coconut, olive, and fish oil. This article presents the new LE nutrition and energy functions but also its biochemical, metabolic, and immunomodulating aspects, according to their FA content. LE at 20% when infused from 1.0 to 2.0 g/kg body weight/day rates, either alone or in association with amino acids and glucose, are safe and well tolerated in routine clinical practice. LE combining SO with medium-chain triglycerides and/or olive oil have less omega-6 PUFA and are better metabolized, with less inflammatory and immunosuppressive effects than in relation to pure SO-based LE. The omega-3 PUFA used alone or as component of a new and complex LE (soy, MCT, olive and fish oil) has demonstrated anti-inflammatory and immunomodulatory effects.

Intravenous Lipid Emulsion for the Treatment of Drug Toxicity

Intravenous lipid emulsion (ILE) has emerged as a powerful antidote for the treatment of drug toxicity in the past decade. Initial efficacy of ILE was shown in the setting of local anesthetic systemic toxicity (LAST), but recent case reports suggest its consideration in a variety of other drug toxicities. In this review, we will summarize the experimental evidence as well as the clinical experience in using ILE as an antidote. Specifically, we will look at the evidence for using ILE in LAST as well as toxicity due to beta-blockers, calcium-channel blockers, and tricyclic antidepressants. We will also review the current dosing recommendations as well as potential side effects of ILE as an antidote.

The composition of oil phase modulates venous irritation of lipid emulsion-loaded diallyl trisulfide

INTRODUCTION

In this study, a nanoemulsion system (LE) was investigated for intravenous delivery of diallyl trisulfide (DT), which was a lipophilic and venous irritant drug for systemic therapy of bacterial and fungal infection.

METHODS

Egg phospholipid was chosen as the only emulsifier, soybean oil, medium chain triglyceride (MCT), and olive oil were used as the oil phases, forming stable DT LEs (o/w) with small particle sizes. The venous irritation of DT LEs was evaluated by in vitro human umbilical cord endothelial cells (HUV-EC CRL 1730) tolerance model with the intracellular ATP and GTP concentrations as the indices.

RESULTS

The intracellular ATP and GTP reduction changed with the incorporation of a variety of oils, which were strongly related with the free DT concentration of DT LEs.

DISCUSSION

It was deduced that the free DT concentrations of LEs made of various oils depended on the particle sizes of the DT LEs. In conclusion, the oil phases modulated the free DT concentrations by forming DT LEs with different particle sizes, and optimization of the oil phase was an effective method to alleviate the venous irritation of DT LEs.

Emulsifiers' composition modulates venous irritation of the nanoemulsions as a lipophilic and venous irritant drug delivery system

In this study, a nanoemulsion (NE) system was investigated for intravenous delivery of lipophilic and venous irritant drugs. NEs were prepared to deliver diallyl trisulfide (DT) for systemic therapy of bacterial and fungal infection, egg phospholipid was chosen as the main emulsifier, and two co-emulsifiers were also incorporated, including Poloxamer 188 (P188) and Solutol HS 15 (S15). Soybean oil was used as the dispersed phases, forming stable DT NEs with small particle sizes. The venous irritation of DT NEs was evaluated by in vitro human umbilical cord endothelial cells (CRL 1730) compatibility model with the intracellular adenosine triphosphate (ATP) and guanosine triphosphate (GTP) concentrations as the indices. The intracellular ATP and GTP reduction changed with the incorporation of a variety of co-emulsifiers, which varied in a free DT concentration-dependent manner. It was deduced that the free DT concentrations of NEs containing co-emulsifiers were determined by the partition coefficient of DT between oil and surfactant buffer solution. In conclusion, NE was an appropriate delivery system for lipophilic and venous irritant drug, and optimization of the composition of emulsifiers was an effective method to alleviate the venous irritation of DT NEs.