According to a recent Cochrane review, heparin use is NOT more effective than saline flushes. Thanks to Ben Gold for providing this reference.
Bradford NK, Edwards RM, Chan RJ. Link: Normal saline (0.9% sodium chloride) versus heparin intermittent flushing for the prevention of occlusion in long-term central venous catheters in infants and children. Cochrane Database Syst Rev. 2020;4(4):CD010996. doi: 10.1002/14651858.CD010996.pub3.
- The four trials (n=255) directly compared the use of normal saline and heparin; the studies all used different protocols for the intervention and control arms, however, and all used different concentrations of heparin.
- The estimated RR for CVC occlusion per 1000 catheter days between the normal saline and heparin groups was 0.75 (95% CI 0.10 to 5.51; 2 studies, 229 participants; very low certainty evidence).
- The estimated RR for CVC‐associated blood stream infection was 1.48 (95% CI 0.24 to 9.37; 2 studies, 231 participants; low‐certainty evidence).
- The duration of catheter placement was reported to be similar for the two study arms in one study (203 participants; moderate‐certainty evidence), and not reported in the remaining studies.
- This is in agreement with another updated Cochrane review assessing the effectiveness and safety of intermittent locking of CVCs with heparin vs. normal saline to prevent occlusion in adults (11 studies; N=2,392). The pooled analysis did show fewer occlusions with heparin than with normal saline (RR 0.70, 95% CI 0.51 to 0.95; P = 0.02; 1672 participants; 1025 catheters from 10 studies; I² = 14%), but it is based on a very low-quality of evidence given the differences in methodology, unclear allocation concealment, imprecision, and suspicion of publication bias. (López-Briz E, Ruiz Garcia V, Cabello JB, et al. Heparin versus 0.9% sodium chloride locking for prevention of occlusion in central venous catheters in adults. Cochrane Database Syst Rev. 2018;7(7):CD008462. doi: 10.1002/14651858.CD008462.pub3)
My take: This review found there was not enough evidence to determine which solution, saline or heparin, is more effective for reducing complications.
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