Ethanol lock therapy ineffective in treating, preventing central venous catheter infections
The use of ethanol lock therapy did not reduce treatment failure of central line-associated bloodstream infections (CLABSIs) in patients with cancer or haematological disorders, but was associated with an increased risk of catheter occlusion, a recent study found.
“Ethanol lock therapy works in the laboratory to kill even tough-to-eradicate bacterial communities called biofilm,” said first author Dr Joshua Wolf from the Department of Infectious Diseases, St Jude Children’s Research Hospital in Memphis, Tennessee, US. “We knew anecdotally that ethanol lock therapy is used at many hospitals in an effort to prevent new or recurring [CLABSIs] in children with cancer,” he said, though until now, there has been little evidence to prove the effectiveness of this method.
“Based on these results, ethanol lock therapy should not be routinely used in children with cancer or haematologic disorders,” said Wolf.
The double-blind trial conducted in two paediatric hospitals in the US and Australia involved 94 patients aged 6 months to 24 years with cancer, haematological disorders, or undergoing haemopoietic stem cell transplantation who were newly diagnosed with CLABSI. They were randomized to receive ethanol lock therapy (70 percent ethanol; n=48) or placebo (heparinized saline; n=46) for 2–4 hours/lumen/day for 5 days (treatment phase) followed by up to 3 non-consecutive days/week for 24 weeks (prophylaxis phase). All participants also received systemic antibiotics for 10–14 days.
The incidence of treatment failure – a composite of catheter removal or death due to infection, new infection, persistent infection (>72 hours), requirement for additional lock therapy during treatment, and recurrent CLABSI during the prophylaxis phase – was comparable between patients assigned to ethanol lock therapy and placebo (44 percent vs 43 percent, relative risk [RR], 1.0, 95 percent confidence interval [CI], 0.6–1.6; p=0.98). [Lancet Infect Dis 2018;doi:10.1016/S1473-3099(18)30267-6]
Patients on ethanol lock therapy had a higher risk of developing catheter occlusion requiring thrombolytic therapy compared with those on placebo (58 percent vs 33 percent, RR, 1.8, 95 percent CI, 1.1–2.9; p=0.012), which appeared to be more common among patients with external catheters than ports (p=0.0025).
Infusion reactions were also more common among patients on ethanol lock therapy than placebo though the findings were not significant (19 percent vs 9 percent; p=0.23), while incidence of treatment discontinuation due to AEs or patient request was comparable between groups (n=9 vs 10; p=0.72).
CLABSI is a common complication faced by children with cancer and is associated with catheter-related occlusion and venous thrombosis, hospitalization, sepsis, subsequent surgery for catheter removal, and even death, said the researchers.
While antibiotic therapy is commonly used to treat CLABSI, [Clin Infect Dis 2009;49:1-45; Pediatr Infect Dis J 2013;32:905-910] ethanol lock therapy, which involves introducing an antimicrobial solution into the catheter, is thought to reduce the risk of treatment failure, they said.
Among the theories put forth to explain the results of this study were that antibiotic therapy administered through all catheter lumens was potentially adequate to treat biofilm-related CLABSI or that certain bloodstream infections in this patient population were not associated with central line use, rendering ethanol lock therapy ineffective.
The researchers also pointed to the presence of residual ethanol in the lumen even after flushing with saline, which may have had a role to play in the incidence of occlusion, they added.
“[E]thanol can precipitate plasma proteins and heparin flushes used between locks or might interact adversely with microbial biofilm,” they said. Occlusion has also been associated with bloodstream infection in children with cancer, they added. [PLoS One 2013;8:e84869; J Clin Oncol 2006;24:4575-4580]