Compassionate-Use of 4% T-EDTA Lock Solution for Central Venous Lines of Pediatric PN Patients

Parenteral nutrition (PN) is a critical treatment for pediatric patients with intestinal failure (IF), defined as those unable to absorb nutrients enterally due to insufficient bowel length or function. Patients who require long term PN have an indwelling central venous line (CVL) for PN delivery. One risk of long-term PN use is the development of catheter occlusions and interruptions to device's patency. Such obstructions can lead to catheter breakage or embolization of the clot into the bloodstream, which can lead to stroke or death. Other complications related to long term use of indwelling CVLs are central line-associated bloodstream infection (CLABSI) and mechanical breakdown of the CVL. This is one of the most common complications of home PN. Among patients with a long-term CVL there are 250,000-500,000 episodes of CLABSI per year and among patients with CVLs for PN a range of 0.87-8.9 CLABSI episodes per 1000 catheter-days has been reported.

As stated, the development of CVL occlusions is a major risk associated with long term PN use. It occurs in as many as 25% of CVLs that are placed. Occlusion can be either partial or complete and has been defined as a decreased ability to infuse solutions into or withdraw solutions from a CVL. Occlusion can decrease flow rates, increase resistance and pressure, and potentially cause complete inability to withdraw and/or infuse fluid. Attempts at dissolving the occlusion may lead to catheter weakening or rupture due to the excessive pressure exerted on the device. Occlusions put a patient at further risk of morbidity and mortality due to delays in treatment and nutritional supplementation, or from fibrin deposition and resulting clot contributing to CLABSI. Additionally, the patient may have to undergo further invasive surgical interventions to replace the catheter.

Furthermore, the presence of occlusions within the CVL can predispose patients to CLABSIs as the clot can serve as reservoir for bacterial colonization. In some instances, the bacteria associated with the majority of CLABSIs are highly thrombogenic and create an environment suitable for the development additional thrombus. In patients with PN related cholestasis, sepsis is the biggest risk factor leading to the most common cause of death in these patients. Moreover, CLABSI is a major contributor to many other comorbidities (i.e., intestinal failure associated liver disease) and, when recurrent, has been recently shown to be a negative predictor in children who achieved enteral autonomy versus those who did not. CLABSI events are also a significant financial burden to both the patient and healthcare system and compromise to quality of life.

Locking solutions have been used in an effort to prevent CVL occlusions and CLABSIs with varying success. In the United States, saline and heparin have been used as the standard of care lock solution for decades. Both lock solutions however have fallen short of protecting patients against CVL complications and heparin has also caused serious systemic side effects as well as promoting biofilm formation within the lumen of CVLs. Compounded lock solutions such as taurolidine, citrate and ethanol and antibiotics have been used in the attempt to reduce CVL complications. Compounded 70% ethanol lock solutions have been used off label to eradicate organisms in biofilms present in CVLs and hence, treat or prevent CLABSIs. Ethanol also decreases the risk of antimicrobial resistance that may occur if concentrated antibiotic locks are used. Since the use of ethanol locks at Boston's Children Hospital (BCH) the CLABSI rate in IF patients dropped from 9.9 to 2.1 per 1000 catheter-days and reduced our morbidity and mortality. Unfortunately ethanol locks may alter the integrity of selected catheter materials, resulting in catheter breakage and leaching of the plasticizer into the bloodstream and frequent catheter occlusions. One meta analysis raised questions about the effect of the ethanol lock on catheter integrity based on the noted increase in catheter repair rates. Moreover, the currently available supply of sterile ethanol that is used to compound the locks has become prohibitively expensive. Homecare companies and retail pharmacies may no longer be able to provide them and it would be a significant out of pocket expense for patients and families if they had to pay for them. This lack of a reliable and affordable source of ethanol for CVL's places these vulnerable patients at a much higher risk of CLABSI and the associated morbidity and mortality.