Ward David R, Moist Louise M, MacRae Jennifer M, Scott-Douglas Nairne, Zhang Jianguo, Tonelli Marcello, Lok Charmaine E, Soroka Steven D, Hemmelgarn Brenda R
Department of Medicine, University of Calgary, 1403 29th St NW, Calgary, AB T2N 2 T9 Canada.
London Health Sciences Center, University of Western Ontario, London, Ontario Canada.
Can J Kidney Health Dis. 2014 Jul 8;1:15. doi: 10.1186/2054-3581-1-15. eCollection 2014.
We previously reported a reduction in central venous catheter (CVC) malfunction when using once-weekly recombinant tissue-plasminogen activator (rt-PA) as a locking solution, compared with thrice-weekly heparin.
To identify risk factors for CVC malfunction to inform a targeted strategy for rt-PA use.
Retrospective analysis.
Canadian hemodialysis (HD) units.
Adults with newly placed tunnelled upper venous system CVCs randomized to a locking solution of rt-PA(1 mg/mL) mid-week and heparin (5000 u/ml) on the other HD sessions, or thrice-weekly heparin (5000 u/ml).
CVC malfunction (the primary outcome) was defined as: peak blood flow less than 200 mL/min for thirty minutes during a HD session; mean blood flow less than 250 mL/min for two consecutive HD sessions; inability to initiate HD.
Cox regression was used to determine the association between patient demographics, HD session CVC-related variables and the outcome of CVC malfunction.
Patient age (62.4 vs 65.4 yr), proportion female sex (35.6 vs 48.4%), and proportion with first catheter ever (60.7 vs 61.3%) were similar between patients with and without CVC malfunction. After multivariate analysis, risk factors for CVC malfunction were mean blood processed < 65 L when compared with ≥ 85 L in the prior 6 HD sessions (HR 4.36; 95% CI, 1.59 to 11.95), and mean blood flow < 300 mL/min, or 300 - 324 mL/min in the prior 6 HD sessions (HR 7.65; 95% CI, 2.78 to 21.01, and HR 5.52; 95% CI, 2.00 to 15.23, respectively) when compared to ≥ 350 mL/min.
This pre-specified post-hoc analysis used a definition of CVC malfunction that included blood flow, which may result in an overestimate of the effect size. Generalizability of results to HD units where trisodium citrate locking solution is used may also be limited.
HD session characteristics including mean blood processed and mean blood flow were associated with CVC malfunction, while patient characteristics were not. Whether targeting these patients at greater risk of CVC malfunction with rt-PA as a locking solution improves CVC longevity remains to be determined.
我们之前报道过，与每周三次使用肝素相比，每周一次使用重组组织型纤溶酶原激活剂（rt-PA）作为封管液可减少中心静脉导管（CVC）故障。
确定CVC故障的危险因素，为rt-PA的使用制定针对性策略。
回顾性分析。
加拿大血液透析（HD）单位。
新置入隧道式上肢静脉系统CVC的成年人，随机分为在透析周中使用rt-PA（1mg/mL）封管液，其他透析时段使用肝素（5000u/ml），或每周三次使用肝素（5000u/ml）。
CVC故障（主要结局）定义为：血液透析期间30分钟内峰值血流量低于200mL/分钟；连续两次血液透析期间平均血流量低于250mL/分钟；无法开始血液透析。
采用Cox回归确定患者人口统计学特征、血液透析时段CVC相关变量与CVC故障结局之间的关联。
发生CVC故障和未发生CVC故障的患者之间，患者年龄（62.4岁对65.4岁）、女性比例（35.6%对48.4%）以及首次使用导管的比例（60.7%对61.3%）相似。多因素分析后，CVC故障的危险因素为：与前6次血液透析中≥85L相比，平均处理血量<65L（风险比4.36；95%置信区间，1.59至11.95）；与≥350mL/分钟相比，前6次血液透析中平均血流量<300mL/分钟或300 - 324mL/分钟（风险比分别为7.65；95%置信区间，2.78至21.01和风险比5.52；95%置信区间，2.00至15.23）。
这项预先设定的事后分析使用了包含血流量的CVC故障定义，这可能导致对效应大小的高估。结果对使用枸橼酸钠封管液的血液透析单位的可推广性也可能有限。
血液透析时段特征，包括平均处理血量和平均血流量，与CVC故障相关，而患者特征无关。使用rt-PA作为封管液针对这些CVC故障风险较高的患者是否能提高CVC使用寿命仍有待确定。
