Ethanol flush for the prevention of catheter occlusion

Ethanol locks for the prevention of catheter-related infection in patients with central venous catheter: A systematic review and meta-analysis of randomized controlled trials

Background

The widespread use of central venous catheters (CVCs) has exposed patients to a high risk of catheter-related infection (CRI), which is linked to substantial morbidity and mortality. Several strategies for preventing CRI, including ethanol lock prophylaxis, have been explored. This study aimed to provide a comprehensive summary of randomized controlled trials (RCTs) assessing the efficacy and safety of ethanol locks for preventing CRI in patients with CVC.

Methods

We searched six electronic databases, earlier relevant meta-analyses and the reference lists of the included studies for RCTs that assessed the effects of ethanol locks on CRI in patients with CVC versus a control group. Two authors independently assessed the methodological quality of the included studies using the Cochrane Risk of Bias tool and extracted relevant information according to a predesigned extraction form. Data were analyzed using the Cochrane Collaboration’s RevMan 5.3.

Results

Nine studies involving 2451 patients were included. Although limited in power, the results of the meta-analysis indicated a positive effect of ethanol lock prophylaxis on reducing catheter-related bloodstream infection (CRBSI) compared to heparin alone [OR = 0.53, 95% CI 0.34, 0.82, P = 0.004]. The effects on other outcomes, such as exit site infection, catheter dysfunction, catheter removal, thrombosis and mortality, were not statistically significant (P > 0.05). Moreover, although the effect of ethanol on CRBSI was in the expected direction compared to 0.9% NaCl locks, this effect was not statistically significant (P > 0.05).

Conclusions

The present data indicate that ethanol lock prophylaxis is a potential candidate for the prevention of CRBSI in patients with CVC. However, more attention should be paid to the uniform ethanol lock procedure and toxic effects after long-term ethanol lock exposure.

Use of Ethanol Lock Therapy to Reduce the Incidence of Catheter-Related Bloodstream Infections in Home Parenteral Nutrition Patients

BACKGROUND

Catheter-related bloodstream infection (CRBSI) is a serious complication for home parenteral nutrition (HPN) patients. To reduce the incidence of infection in frequently infected HPN patients, prophylactic ethanol lock therapy (ELT) was initiated.

METHODS

Nine patients were selected as candidates for ELT because of their history of recurrent CRBSI. Diagnosis of CRBSI was determined by symptoms correlating with positive peripheral and access device blood cultures. Medical-grade ethyl alcohol 25%-70% was instilled into the central venous access device and allowed to dwell for 2-4 hours. The incidence of CRBSI and catheter changes was compared before and after initiation of ELT.

RESULTS

Nine patients experienced 81 CRBSIs (8.3 per 1,000 catheter-days) before starting ELT vs 9 infections (2.7 per 1,000 catheter-days: relative risk [RR], 0.325; confidence interval [CI] 95%, 0.17-0.64) after ELT. Catheter changes were also reduced from 69 (7.0 per 1000 days) before ELT to 1 (0.3 per 1,000 days: RR, 0.043; CI 95%, 0.01-0.25) after ELT. No significant adverse effects were noted, although some patients complained of transient dizziness and nausea.

CONCLUSIONS

ELT shows promise in reducing the incidence of CRBSI in the frequently infected HPN population. Further studies are warranted.

The Effects of Prolonged Ethanol Exposure on the Mechanical Properties of Polyurethane and Silicone Catheters Used for Intravascular Access

Background:

Products containing alcohol are commonly used with intravascular devices at insertion, to remove lipids from occluded intravascular devices used during parenteral nutrition, and increasingly for the prevention and treatment of intravascular device-related bloodstream infection. The effects of alcohol on the integrity of intravascular devices remain unknown.

Methods:

Two types of widely used commercial peripherally inserted central catheters, one made of polyether-urethane and one made of silicone, were exposed to a 70% etha-nol lock solution for up to 10 weeks. Mechanical testing was performed to identify force-at-break, stress, strain, modulus of elasticity, modulus of toughness, and wall area of ethanol-exposed and control catheters.

Results:

No significant differences between exposed and unexposed catheters were identified for any of the mechanical parameters tested except for a marginal reduction in the modulus of elasticity for both polyetherurethane and silicone catheters and minor increases in the wall area of polyetherurethane catheters.

Conclusions:

These data indicate that exposure to a 70% ethanol lock solution does not appreciably alter the integrity of selected commercial polyetherurethane and silicone catheters. Given the greatly expanded use of alcoholic solutions with intravascular devices of all types, we believe that manufacturers would be well advised to subject their catheters and other intravascular devices to formal testing of the type employed in this study.

Ethanol causes protein precipitation--new safety issues for catheter locking techniques

OBJECTIVE

The ethanol lock technique has shown great potential to eradicate organisms in biofilms and to treat or prevent central venous catheter related infections. Following instillation of ethanol lock solution, however, the inherent density gradient between blood and ethanol causes gravity induced seepage of ethanol out of the catheter and blood influx into the catheter. Plasma proteins so are exposed to highly concentrated ethanol, which is a classic agent for protein precipitation. We aimed to investigate the precipitating effect of ethanol locks on plasma proteins as a possible cause for reported catheter occlusions.

METHODS

Plasma samples were exposed in-vitro to ethanol (concentrations ranging from 7 to 70 v/v%) and heparin lock solutions. In catheter studies designed to mimic different in-vivo situations, the catheter tip was placed in a plasma reservoir and the material contained within the catheter was analyzed after ethanol lock instillation. The samples underwent standardized investigation for protein precipitation.

RESULTS

Protein precipitation was observed in plasma samples containing ethanol solutions above a concentration of 28%, as well as in material retrieved from vertically positioned femoral catheters and jugular (subclavian) catheters simulating recumbent or head down tilt body positions. Precipitates could not be re-dissolved by dilution with plasma, urokinase or alteplase. Plasma samples containing heparin lock solutions showed no signs of precipitation.

CONCLUSIONS

Our in-vitro results demonstrate that ethanol locks may be associated with plasma protein precipitation in central venous catheters. This phenomenon could be related to occlusion of vascular access devices locked with ethanol, as has been reported. Concerns should be raised regarding possible complications upon injection or spontaneous gravity induced leakage of such irreversibly precipitated protein particles into the systemic circulation. We suggest limiting the maximum advisable concentration of ethanol to 28 v/v% in catheter lock solutions.

Complementary mass spectrometric approaches and scanning electron microscopy to study the structural stability of polyurethane tunneled dialysis catheters after exposure to ethanol solutions

RATIONALE

Ethanol lock is an emerging therapeutic option for preventing and/or controlling catheter-associated infection. A previous study of silicone catheters showed they underwent no polymer degradation when kept in 60% ethanol for 15 days at 37 °C. The stability of the more widely used polyurethane catheters was studied here in the same way.

METHODS

A qualitative and quantitative study of the stability of Carbothane® catheters was performed following their immersion at 37 °C in different solvents (0.9% sodium chloride as control medium and 40%, 60%, 95% ethanol solutions) for different periods of time (from 5 min to 15 days) using scanning electron microscopy and complementary mass spectrometry techniques.

RESULTS

Electron ionization analysis of the 95% ethanol storage solutions revealed the release of about 45 products (8 of which were major) subdivided into two groups according to their fragmentation patterns. Combining all the mass spectrometric data made it possible to propose structures. Group I (major) originated from the polycarbonate diol component (soft segment) and group II (minor) from the dicyclohexylmethane-4,4'-diisocyanate component (rigid segment). Semi-quantitative gas chromatography/mass spectrometry (GC/MS) analysis showed that no significantly higher release was observed after immersion for 30 min at 37 °C in 40% ethanol (mean ratio = 0.677 ± 0.068) than after immersion in reference 0.9% sodium chloride solution for 15 days (0.837 ± 0.127).

CONCLUSIONS

A 30 min-40% (v/v) ethanol solution can be considered as safe for preventing the infectious complications of Carbothane® dialysis catheters, and a 30 min-60% (v/v) ethanol treatment can be occasionally used to eradicate established biofilm.

Ethanol locks to prevent catheter-related bloodstream infections in parenteral nutrition: a meta-analysis

OBJECTIVE

Patients with pediatric intestinal failure (IF) depend on parenteral nutrition for growth and survival, but are at risk for complications, such as catheter-related bloodstream infections (CRBSIs). CRBSI prevention is crucial, as sepsis is an important cause of IF-associated liver disease and mortality. We aim to estimate the pooled effectiveness and safety of ethanol locks (ELs) in comparison with heparin locks (HLs) with regard to CRBSI rate and catheter replacements for pediatric IF patients with chronic parenteral nutrition dependence.

METHODS

A systematic review without language restriction was performed on Medline (1948-2010), Embase (1980-2010), and conference programs and trial registries up to December 2010. Search terms included "Catheter-Related Infections," "Catheter," "Catheters, Indwelling," "alcohol," "ethanol," and "lock." Two authors identified 4 retrospective studies for the pediatric IF population. Double, independent data extraction using predefined data fields and risk of bias assessment (Newcastle-Ottawa scale) was performed.

RESULTS

In comparison with HLs, ELs reduced the CRBSI-rate per 1000 catheter days by 7.67 events and catheter replacements by 5.07. EL therapy decreased the CRBSI rate by 81% and replacements by 72%. One hundred eight to 150 catheter days of EL exposure were necessary to prevent 1 CRBSI and 122 to 689 days of exposure avoided 1 catheter replacement. Adverse events were rare and included thrombotic events.

CONCLUSIONS

In pediatric patients with IF, EL is a more effective alternative to HL. Adverse events include thrombotic events.

Ethanol lock therapy to reduce the incidence of catheter-related bloodstream infections in home parenteral nutrition patients with intestinal failure: preliminary experience

BACKGROUND

Catheter-related bloodstream infections (CRBSI) cause morbidity and mortality in patients with intestinal failure dependent on parenteral nutrition. Ethanol lock of central venous catheters may decrease CRBSI, but limited pediatric data are available.

METHODS

Home parenteral nutrition patients with at least one previous CRBSI were initiated on a 70% ethanol lock protocol for a minimum of 4 hours. Infection rates (per 1000 catheter days) before and after initiation of ethanol locks were compared using a paired t test.

RESULTS

Ten patients (4 girls; median age, 44 months [range, 31-129 months]) began ethanol lock therapy after a total of 91 CRBSIs (37 gram-positive, 30 gram-negative, and 24 fungal) with a mean of 10.2 ± 6.2 per 1000 catheter days. Patients received ethanol lock for an average of 227 ± 64 days with only 3 CRBSI occurring (CRBSI rate of 0.9 ± 1.8 per 1000 catheter days [P = .005]). Central venous catheter replacements decreased from 5.6 per 1000 days to 0.3 per 1000 days posttherapy (P = .038). Ethanol lock was discontinued in 2 of 10 patients because of catheter thrombosis.

CONCLUSION

Preliminary results demonstrate a significant decrease in CRBSI with a 70% ethanol lock protocol. Catheter thrombosis may be a limitation that needs to be addressed. With such a dramatic therapeutic effect, a randomized trial is feasible and should be performed.

Central venous port systems as an integral part of chemotherapy

BACKGROUND

Port systems are easy to implant on an in- or outpatient basis and provide reliable, long-lasting central venous access. They are used mainly for cancer patients.

METHODS

This article is based on a selective literature review, the guidelines of the German Society for Nutrition Medicine and of the European Society for Clinical Nutrition and Metabolism, and the recommendations of the German Society for Pediatric Oncology and Hematology.

RESULTS

In modern oncology, central venous port systems are increasingly replacing short-term and permanently tunneled central venous catheters. They are indicated for patients who need long-term intravenous treatment involving, e.g., the repeated administration of chemotherapeutic drugs, parenteral nutrition, transfusions, infusions, injections, and/or blood sample collection. Port systems can markedly alleviate the burden of intravenous therapy and thereby improve these patients' quality of life. The planning, preparation, and performance of port system implantation require meticulous attention to detail. The rate of implantation-associated complications is less than 2% in experienced hands; overall complication rates have been reported from 4.3% to as high as 46%. The proper postoperative use and care of the port system are of decisive importance to the outcome. Reported infection rates during port system use range from 0.8% to 7.5% in current clinical studies.

CONCLUSION

The treatment, follow-up care, and rehabilitation of cancer patients are interdisciplinary tasks. Optimal treatment and complication avoidance require a collaborative effort of all of the involved specialists-not just the physician implanting the port system, but also the oncologists, nutritionists, visiting nurses, and other home health care providers. Continuing medical education, too, plays a role in improving outcomes.

Lock method using sodium hydroxide solution to clear occluded central venous access devices

Occlusion of central venous access devices (CVADs) is not an uncommon problem duringlong-term parenteral nutrition. A number of techniques have been developed to deal with obstructed CVADs. This study investigated the effectiveness of the sodium hydroxide (NaOH) lock method for gradual CVAD occlusion. When a progressively declining flow was noticed, 0.1 N NaOH solution was injected into the CVAD and locked. Nineteen CVAD occlusions in 11 home parenteral nutrition patients were treated Sixteen of 19 trials cleared the occlusions, whereas 3 of 19 failed. One of the failures was due to a mechanical occlusion and the other two were able to be restored by using ethanol. There were no significant complications. The benefits of this method are: (1) a shorter treatment time and a lower dose than NaOH infusion therapy, (2) it does not require hospital admission and (3) it does not result in bursting of the catheter.

Mass spectrometry and scanning electron microscopy study of silicone tunneled dialysis catheter integrity after an exposure of 15 days to 60% ethanol solution

Anti-infectious lock is an emerging therapeutic option for preventing and/or controlling catheter-associated infection. Ethanol has widespread bactericidal activity, limited side effects, and low risk of inducing antimicrobial resistance. However, concerns have been raised about ethanol-induced catheter structural degradation. In this study, silicone catheters were immersed at 37 degrees C in three different solvents: 0.9% sodium chloride, 60% ethanol, and 95% ethanol for 4 h, 15 days and 15 days after a first storage of 4 h. Scanning electron microscopy (magnification 1000-20 000 times) of the inner surface of the catheter revealed no damage to the lumen surfaces of catheters immersed in 95% ethanol for 15 days compared with the reference catheter. Gas chromatography/mass spectrometry (GC/MS) and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS) analysis of the storage solutions revealed a significant release of polydimethylsiloxanes having a number of dimethylsiloxane units lower than 30 in the 95% ethanol solution and a structure highly consistent with a cyclic structure. Most release occurred within the first 4 h of exposure. In contrast, there was no difference in the small amounts of silicone released in 0.9% sodium chloride as reference and 60% ethanol solution, whatever the exposure time. These results should allow the development of clinical trials to assess the efficacy of the 60% ethanol lock technique in preventing or controlling the infectious complications of silicone dialysis catheters.

Complications of long-term home total parenteral nutrition: their identification, prevention and treatment

The purpose of this review is to describe the most common complications of home total parenteral nutrition, their identification, treatment and prevention. Data sources were manuscripts and abstracts published in the English literature since 1968. Studies were selected for summarization in this review on the basis of clinical relevance to the practicing clinician. Home total parenteral nutrition is a relatively safe, life-saving method for nutrient delivery in patients with compromised gastrointestinal function. However, numerous complications, with associated morbidity and mortality, involving the delivery system and the gastrointestinal, renal, and skeletal systems may develop. Catheter-related complications are often preventable and treatable when they occur, although renal and bone abnormalities have elusive etiologies.

Review article: artificial nutritional support for improved patient care

Malnutrition is common and undiagnosed in the majority of affected hospital patients; it is associated with impaired organ function, morbidity, and increased length of hospital stay. Artificial nutritional support in malnourished patients leads to improvement in nutritional status and clinical outcome. Nutritional support is required in malnourished patients, patients who are unable to take normal diet and patients with intestinal failure. Gastroenterologists are required to supervise patients with intestinal failure, to insert endoscopic feeding devices, and increasingly to participate in, or lead, nutritional support teams. Major developments in nutrient delivery have included percutaneous endoscopic feeding devices, the recognition that enteral feeding is possible in patients with gastric stasis, and that nutrient needs can be met by peripheral parenteral nutrition. There is much interest in the use of new substrates, or substrates delivered in pharmacological doses such as glutamine and arginine, to manipulate the response to disease. Many hospitals lack an organized approach to artificial nutritional support. Patients continue to suffer from a lack of treatment or the consequences of inappropriate or inadequate treatment. This article reviews the current status of artificial nutritional support and provides guidelines for patient management.

Treatment of central venous catheter occlusions with ethanol and hydrochloric acid

BACKGROUND

Occluded central venous lines (CVLs) is a major problem in pediatric patients.

METHODS

To relieve obstructed catheters, infusions of ethanol (up to 3 mL of a 70% solution) for presumed lipid occlusions and hydrochloric acid (HCl, 0.1 N, up to 3 mL) for presumed mineral and drug precipitates were given in an attempt to relieve obstructed catheters.

RESULTS

Patency was restored in 34 of 39 occluded catheters over an 18-month period.

CONCLUSIONS

Clearing occluded CVLs with ethanol and HCl is not only beneficial to the patient but also offers considerable cost savings compared to CVL replacement.

Auditing the effect of experience and change on home parenteral nutrition related complications

A prospective record of all patients receiving home parenteral nutrition (HPN) in Tayside since 1980 has been used to audit the effect of experience and specific policy changes on HPN related complications. Total HPN related complications fell significantly over the years from 1.59 complications per treatment year during the initial 5 years of HPN experience to the current rate of 0.36 complications per treatment year. Specific policy changes, such as modification of the glucose concentration of feed, could also be shown to produce a significant benefit in the reduction of complications. Increasing experience with HPN results in a fall in complication rates, however, continuous audit of HPN is essential to determine the effect of policy changes on complication rates.

Home parenteral nutrition in Tayside 1980-1992

The experience of Home Parenteral Nutrition (HPN) in Tayside over the last 13 years has been reviewed with particular reference to the indications for, complications of, and quality of life whilst receiving HPN. The observed complication rate has been compared with that of the UK experience, and the observed complication rate for the first seven years of HPN experience has been compared with the subsequent six years. The Tayside experience equates broadly with that of the UK, although there was a different pattern of complications. Increasing experience with HPN has resulted in a fall in HPN related complications to 1 per 3.4 treatment years in Tayside, a rate as low as that of the most experienced HPN centre in the UK.