Outcomes of the Use of Sodium Bicarbonate (8.4%) Solution as a Catheter Lock Solution to Prevent Hemodialysis Catheter Loss Due to Lumen Clot Formation

A randomized, comparative clinical, open-label trial at Coney Island Hospital, in Brooklyn, NY. The study period was between October 1, 2016 and March 30, 2018, a total of 546 days. All patients provided written informed consent before enrollment. The trial protocol was approved by Maimonides Medical Center Investigational Review Board: Study #2015-06-25-CIH. Patients presenting over the age of 18 requiring hemodialysis via CVCs were eligible. One patient was excluded due to having a poor venous system with inadequate blood flow for appropriate HD. No other patient was excluded from the study.

A total of 451 patients undergoing HD with CVCs were included in the study. Patients had tunneled internal jugular vein (IJV) catheters, non-tunneled IJV catheters, and non-tunneled femoral vein catheters. All patients were randomly assigned based on simple sequential order into one of two groups: NSCLS (n = 226) and SBCLS (n = 225). NSCLS patients were assigned between October 1, 2016 and June 30, 2017. SBCLS patients were assigned between July 1 2017 and March 30, 2018. Recruitment ended based on the similar number of enrolled participants between groups. A primary or co-investigator enrolled the participant into the trial and assigned the participant to the intervention at the time of presentation. Both groups received heparin-free HD treatment. Before each HD treatment, catheters and connections were inspected for leaks, evidence of damage, exit-site infection and tunnel infection. Intraluminal SBCLS or NSCLS lock solution was removed before connecting the HD catheter to a dialysis machine prior to any treatment.

During each treatment, patients were monitored for complications and standard care was provided to every patient. After each treatment, blood was rinsed from dialysis lines with NS solution back to the patient. Upon the conclusion of treatment, all catheters were flushed and locked with 10 mL of NSCLS or SBCLS, respective of their groups. Approximately 2 mL of the injected solution remained locked within the catheter. Catheter exit site dressing changes occurred after each HD treatment.

For patients that had clotted catheters, thrombolytic therapy was not instituted. Risk assessment performed by our hospital's risk management department determined that the net risk of thrombolytic use in their opinion was greater than the risk of catheter replacement by our qualified operators.

CVCs used in the study varied according to the patient's needs and consisted of Mahurkar non-tunneled catheters and Palindrome tunneled catheters. All CVCs were inserted by an expert operator under strict aseptic protocol. Catheter care was performed by trained dialysis staff according to our hospital's Administrative Policy and Procedure Manual. At the end of dialysis, all catheters were flushed and locked with one of two solutions. SBCLS contained 7.5% or 8.4% SB at a pH of 7.0-8.5, and was used to lock SBCLS-group catheters. NSCLS contained 0.9% sodium chloride at a pH 4.5-7.0, and was used to lock NSCLS-group patient catheters. Both are sterile non-pyrogenic solutions.