Co-first authorship Ming-Guang Zhang contributed equally as the co-first author.
Preservative-free 0.9% sodium chloride for flushing and locking peripheral intravenous access device: a prospective controlled trial
Version of Record online: 29 NOV 2012
© 2012 Wiley Publishing Asia Pty Ltd and Chinese Cochrane Center, West China Hospital of Sichuan University
Journal of Evidence-Based Medicine
Volume 5, Issue 4, pages 205–208, November 2012
How to Cite
Wang, R., Luo, O., He, L., Li, J.-X. and Zhang, M.-G. (2012), Preservative-free 0.9% sodium chloride for flushing and locking peripheral intravenous access device: a prospective controlled trial. Journal of Evidence-Based Medicine, 5: 205–208. doi: 10.1111/jebm.12004
Funding source Scientific Research Program of Public Health Department of Sichuan Province China (No. 120223).
Conflicts of interest None to declare.
- Issue online: 29 NOV 2012
- Version of Record online: 29 NOV 2012
- Accepted manuscript online: 1 NOV 2012 05:04AM EST
- Received 3 October 2012; accepted for publication 22 October 2012.
- Infusion nursing;
- normal saline;
- heparin saline;
- peripheral intravenous access device
Background and aim: In Mainland China, heparin saline solution is commonly used for flushing and locking peripheral intravenous access devices in clinical practice for a long time. We conducted a prospective controlled trial to compare the effectiveness and safety of preservative-free 0.9% sodium chloride solution versus heparin saline solution as flushing and locking solution for peripheral intravenous access devices.
Methods: Patients with gastroenterological or hepatic diseases were enrolled for this study from August 2011 to October 2011. After non-randomized allocation, preservative-free 0.9% sodium chloride was used as flushing and locking solution in the sodium chloride solution group, while hepatic solution (10 U/mL) was given in the heparin saline solution group. The device related complications and its maintenance duration were compared between two groups. One-way ANOVA, Chi2, or Mantel-Haenszel test were performed using SPSS 13.0 and RevMan 5.0.
Results: Totally, 181 and 178 peripheral intravenous access devices in the sodium chloride solution and heparin saline solution groups were included and analyzed. Results indicated than sodium chloride solution did not increase the risks of occlusion (7.7% vs. 7.9%) and other adverse events of peripheral intravenous access devices (P = 0.163). Sodium chloride solution neither shortened the duration of peripheral intravenous access devices maintenance (3.6 ± 1.1 days vs. 3.7 ± 1.2 days, P = 0.651), nor increased the proportion of abnormal withdrawal (29.3% vs. 31.5%, P = 0.654).
Conclusion: Sodium chloride solution is as effective and safe as conventional heparin saline solution for flushing and locking peripheral intravenous access devices, which results from our evidence-based study and should be transferred to other nurses in China.
In Mainland China, heparin saline solution (HS) is commonly used for flushing and locking peripheral intravenous access devices (PIVADs) in clinical practice for a long time. It means that HS is still accepted as a standard solution to flush and lock PIVADs by nurses in China. Heparin is an anticoagulant that is effective to prevent coagulation and occlusion in PIVADs during an infusion interval by our past knowledge and understanding. If coagulation happens, PIVADs will fail during the normal administration period and have to be changed. Empirically, in China nurses really prefer HS to flush and lock PIVADs concerning the safety.
However, based on relevant studies, US Infusion Nurses Society (INS) has updated its ‘Standards of Practice’ in 2011 and recommended preservative-free 0.9% sodium chloride, the normal saline solution (NS), for flushing and locking PIVADs, while HS has been only recommended for central venous access devices (1). This new conception becomes a great challenge of the daily work of Chinese nurses. As our knowledge showed, in China nurses have been quite a lack of relevant clinical evidence to well understand and accept this new approach before (2). Until 2005, most nurses believed that the effect of HS solution would be better than that of NS solution in locking the catheter, and the higher dose of HS solution would be better than the lower dose (2). Therefore, more attention should be paid to different concentrations of HS solution for locking peripheral intravenous catheter (3, 4). Although NS solution for locking PIVADs has been gradually studied in Chinese nursing field in recent years (5, 6), it has not reached a definite conclusion or come to consensus. Therefore, we designed and conducted a clinical controlled trial to compare the effectiveness and safety between NS and HS for flushing and locking PIVADs.
In this trial, we prospectively enrolled the patients with gastroenterological or hepatic diseases concurrently admitted in the Department of Gastroenterology, West China Hospital, from August 2011 to October 2011. The patients with acute massive GI bleeding, severe acute pancreatitis, and hepatic diseases of Child grade C were excluded in this study.
Those patients were nonrandomly allocated into two nursing groups. Two researchers (Wang R and Luo O) completed flushing and locking PIVADs procedures. In the NS group (Wang R), preservative-free 0.9% sodium chloride was used as flushing and locking solution, while hepatic solution (10 U/mL) was given in the HS group (Luo O). The manipulation technique of flushing and locking PIVADs was strictly according to the INS Standard of Practice 2011 (1). Flushing with positive pressure and impulsive locking PIVAD catheters was regarded as the critical technique. Both BD-22 and BD-24 (Becton, Dickinson and Company, USA) two types of PIVADs were used in this study.
The catheter-related complications or adverse events were observed and recorded, including catheter occlusion, dropout, itch, leakage and phlebitis, among which catheter occlusion was most associated with locking solution. The withdrawal rates of PIVADs due to abnormal causes were compared between the two groups. The duration of PIVADs maintenance (days) was considered for comparison, and the proportion of PIVADs maintained at least 96 hours.
Sample size was calculated using equal efficacy model, as reported in a Chinese study that the rates of successful maintenance more than three days were 93.1% and 64.9% in HS and NS groups respectively (6). Therefore, the size in each group was expected to be at least 60 patients. In this study, we planned to expand the size up to 180 patients in each group, which was three times the expectancy.
The duration length of PIVADs maintenance, the incidence of PIVADs complications and the causes of PIVADs withdrawal were observed and analyzed using statistic software SPSS 13.0 (SPSS, Chicago, IL, USA) and RevMan 5.0 (The Nordic Cochrane Center, Cochrane Collaboration, Copenhagen, Denmark). One-way ANOVA test was used to compare means of continuous data. For dichotomous data, Chi2 test or Fisher's exact test was used to compare frequencies. Mantel-Haenszel (M-H) method was used to calculate the risk difference (RD) and its 95% confidence interval (CI) of dichotomous data. P value of less than 0.05 (two-sided) was considered significant.
Totally, 181 and 178 PIVADs were included for analysis in the NS and HS groups, respectively. Baseline characteristics of the two groups were comparable without significant differences (Table 1), such as gender (P = 0.156), age (P = 0.375) and diseases category (P = 0.341). The BD-24 PIVAD was applied less in the NS group, without significant difference (50.8% vs. 59.6%, P = 0.097).
|Group||N (PIVADs)||Gender (n)||Age (Mean ± SD, year)||Disease||Type of PIVADs|
|NS group||181||109||72||55.1 ± 16.2||71||99||8||3||89||92|
|HS group||178||120||58||53.5 ± 17.5||63||95||16||4||72||106|
Device related complications
Complications of PIVADs involved occlusion, dropout, itch, leakage, and phlebitis. The leakage of PIVADs was the most commonly seen complication in both the NS and HS groups (16.0% vs. 13.5%, respectively). Occlusion of PIVADs was the secondary (7.7% vs. 7.9%, respectively). The comparison of complication risks did not show any statistical difference between the two groups (P = 0.163; Table 2, Fig1).
|Group||N (PIVADs)||Duration of PIVADs maintenance, n (%)||Complications of PIVADs, n (%)||Causes of PIVADs withdrawal, n (%)a|
|<96 hours||≥96 hours||Dropout||Itch||Leakage||Occlusion||Phlebitis||Abnormal||Normal|
|NS group||181||75 (41.4%)||106 (58.6%)||3 (1.7%)||0 (0)||29 (16.0%)||14 (7.7%)||7 (3.9%)||53 (29.3%)||128 (70.7%)|
|HS group||178||80 (44.9%)||98 (55.1%)||1 (0.6%)||3 (1.7%)||24 (13.5%)||14 (7.9%)||14 (7.9%)||56 (31.5%)||122 (68.5%)|
These complications were the abnormal causes of PIVADs withdrawal, accounting for 29.3% versus 31.5% in the NS and HS groups, respectively (P = 0.654; Table 2). Besides, the results also indicated that the duration of PIVADs maintenance of the two groups was nearly the same (NS vs. HS, 3.6 ± 1.1 days vs. 3.7 ± 1.2 days, P = 0.651). The proportion of PIVADs maintained at least 96 hours were 58.6% and 55.1% in the NS and HS groups, respectively (P = 0.502; Table 2). However, the RDs between the two groups did not show any statistical significance (Fig 1).
Infusion therapy is a great progress and achievement in medical practice. Vascular access is one of the most important parts of infusion therapy and peripheral intravenous assess is the most common approach for infusion therapy. Flushing and locking are two important procedures of infusion nursing and influence both the effectiveness and safety of infusion. Flushing is the act of moving fluids, drugs, blood, blood products, and nutrients out of a vascular access device into the blood stream, ensuring delivery of those components and verifying device patency. Locking is the instillation of a solution into a vascular access device to maintain device patency. Therefore, the choice of solutions for flushing and locking should be always paid attention to by infusion nurses.
Traditionally, in China, heparin solution is regularly used for flushing and locking PIVADs, which means the opinion and knowledge may be lagged behind the INS Standard of Practice (2011) (1). The results of this study proved that preservative-free 0.9% sodium chloride solution was as effective and safe as the conventional agent, heparin solution. Preservative-free 0.9% sodium chloride as a flushing and locking solution didn't increase the risks of occlusion and other adverse events of PIVADs. In addition, it neither shortened the duration of PIVADs maintenance, nor increased the proportion of abnormal withdrawal.
Actually, since 1980s, the value of HS for locking peripheral intravenous catheter has already been questioned in western countries (7, 8). A following research indicated that heparinized saline was not required to maintain the patency of a peripheral intravenous catheter, and the use of saline solution alone was less irritating, causing less phlebitis as well as saving nursing time (9). A latest research also showed that the use of heparin was unnecessary for the maintenance of IV access devices in neonates (10). Another research even concluded that switching from heparinized solution to normal saline for catheter intermittent lock of totally implantable long-term central vascular access device ports in adult patients seemed a safe procedure (11, 12). By now, literature search in foreign databases and systematic review has concluded that insufficient evidence supported heparin solution might be more effective than saline solution to flushing catheters (13, 14).
However, there was still different opinion among Chinese infusion nursing researchers. A latest meta-analysis based on Chinese population included 15 studies and totally 1594 patients (15). The results of this meta-analysis showed that two kinds of locking catheter solutions, heparin saline or normal saline alone, were significantly different in catheter occlusion rate. HS seemed to be better to maintain the patency (OR = 0.36, 95% CI 0.20 to 0.66, P = 0.0008), although the incidence of phlebitis and the average catheter maintenance duration were similar (15). Therefore, the result of comparison conducted in China was quite different from that conducted in foreign countries in catheter patency. Accordingly, using heparin saline as a flushing and locking solution to maintain the patency of peripheral intravenous catheter was kept in usual practice among Chinese nurses. However, to be strict, the previous relevant Chinese clinical studies were generally of poor methodological quality, in despite of some labeled as random allocation, which were mislabeled in fact and might potentially involve selection bias, performance bias or observation bias. The present evidences may not only be exactly a challenge for Chinese nursing practice, but also an evidence-based chance to transform our recognition of infusion nursing in China in the future. Further large-scaled high-qualified multi-centre randomized controlled trials based on Chinese population must be expected by Chinese nursing researchers to resolve the controversy on whether heparin is really necessary in flushing and locking PIVADs.
The authors thank for the kind academic support from Y-L Luo, Infusion Nursing IV Team, West China Hospital, Sichuan University, China, and also for the methodological support from Dr. X-Z Chen, Department of Gastrointestinal Surgery, West China Hospital, Sichuan University, China.
- 1Infusion Nurses Society. Infusion nursing standards of practice. Journal of Infusion Nursing 2011; 34(1 Suppl): S1–110.
- 2Development of sealing technique for venous catheter. Journal of Nursing Science 2005; 20(9): 78–81 (in Chinese)., .
- 4Influence of different doses of heparin in sealing-tube fluids on bleeding and blood coagulation mechanisms of old patients. Chinese Nursing Research 2007; 21(8A): 2013–4 (in Chinese)., , , , .
- 5Comparison of the sealing effects of vein permanent needle between normal saline and natrium heparin. Nursing Practice and Research 2009; 6(2): 32–3 (in Chinese)..
- 6Effectiveness of two kinds locking solution for peripheral intravenous catheter. Jilin Medical Journal 2009; 30(14): 1427–8 (in Chinese)., , .
- 14Heparinised saline or normal saline Journal of Perioperative Practice 2008; 18(10): 440–1.
- 15Efficacy and safety of two kinds of tube-sealing solution for intravenous catheter needle. Journal of Nursing 2012; 19(7B): 39–43 (in Chinese)., , , .