Flushing and locking of intravenous catheters are thought to be essential in the prevention of occlusion. The clinical sign of an occlusion is catheter malfunction and flushing is strongly recommended to ensure a well-functioning catheter. Therefore fluid dynamics, flushing techniques, and sufficient flushing volumes are important matters in adequate flushing in all catheter types. If a catheter is not in use, it is locked. For years, it has been thought that the catheter has to be filled with an anticoagulant to prevent catheter occlusion. Heparin has played a key role in locking venous catheters. However, the high number of risks associated with heparin forces us to look for alternatives. A long time ago, 0.9% sodium chloride was already introduced as locking solution in peripheral cannulas. More recently, a 0.9% sodium chloride lock has also been investigated in other types of catheters. Thrombolytic agents have also been studied as a locking solution because their antithrombotic effect was suggested as superior to heparin. Other catheter lock solutions focus on the anti-infective properties of the locks such as antibiotics and chelating agents. Still, the most effective locking solution will depend on the catheter type and the patient’s condition.

Heparin has been used for years as a locking solution in totally implantable venous access devices. Normal saline (NS) might be a safe alternative for heparin. However, evidence of non-inferiority of NS versus heparin is lacking. We randomly allocated 802 cancer patients with a newly inserted port either to heparin lock (300 U/3 ml) or to NS lock groups in a 1:1 assignment ratio. The primary outcome was the number of functional complications, which was defined as ‘easy injection, impossible aspiration’ at port access. Secondary outcomes included all functional problems and catheter-related bacteraemia. We hypothesised that NS locks do not cause more functional problems and catheter-related bacteraemia than heparin locks. Non-inferiority is established if the upper limit of the confidence interval (CI) for the relative risk of NS versus heparin is <1.4. Three hundred and eighty-two patients from the NS group and 383 from the heparin lock group were included in the analysis. The incidence rate of our primary outcome (easy injection, impossible aspiration) was 3.70% (95% CI 2.91%–4.69%) and 3.92% (95% CI 3.09%–4.96%) of accesses in the NS and heparin groups, respectively. The relative risk was 0.94% (95% CI 0.67%–1.32%). Catheter-related bloodstream infection was 0.03 per 1000 catheter days in the NS group and 0.10 per 1000 catheter days in the heparin group. NS is a safe and effective locking solution in implantable ports if combined with a strict protocol for device insertion and maintenance.

Objectives To assess the effect on needed nursing time for dressing change. Design, setting, participants A parallel-group, open-label, randomised controlled trial in patients who are in need for a peripherally inserted central catheter insertion in one teaching hospital in Belgium. The follow-up lasted 180 days or until catheter removal, whatever came first. A computer generated table was used to allocate devices. Randomised patients were 105 adults (StatLock, n=53; SecurAcath, n=52) and primary analysis was based on all patients (n=92) with time measurements (StatLock, n=43; SecurAcath, n=49). Interventions StatLock which has to be changed weekly versus SecurAcath which could remain in place for the complete catheter dwell time. Main outcome measure Needed time for the dressing change at each dressing change (SecurAcath) or at each dressing change combined with the change of the securement device (StatLock). Results Median time needed for dressing change was 7.3 min (95% CI 6.4 min to 8.3 min) in the StatLock group and in the SecurAcath group 4.3 min (95% CI 3.8 min to 4.9 min) (P<0.0001). The time in the SecurAcath group was reduced with 41% (95% CI 29% to 51%). Incidence rates of migration, dislodgement and catheter-related bloodstream infection were comparable across groups. Pain scores were higher with SecurAcath than with StatLock at insertion (P=0.02) and at removal (P<0.001) and comparable during dressing change (P=0.38) and during dwell time (P=0.995). User-friendliness was scored at insertion and removal. All statements regarding the user-friendliness were scored significantly higher for StatLock than for SecurAcath (P<0.05). Only for the statement regarding the recommending routine use of the device, which was asked at removal, no difference was found between the two devices (P=0.32). Conclusion Use of SecurAcath saves time during dressing change compared with StatLock. Training on correct placement and removal of SecurAcath is critical to minimise pain. Trial registration number NCT02311127; Pre-results.