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The maintenance of totally implanted venous access devices: When the difference is made by the nursing practice
European Journal of Oncology Nursing 21 (2016) 272e273
Contents lists available at ScienceDirect
European Journal of Oncology Nursing journal homepage: www.elsevier.com/locate/ejon
Correspondence
The maintenance of totally implanted venous access devices: When the difference is made by the nursing practice Correspondence about the paper “Normal saline versus heparin solution to lock totally implanted venous access devices: Results from a multicenter randomized trial” by Dal Molin et al. (EJON 19;2015:638e643)
Keywords: Flushing Heparin Indwelling catheter Normal saline Nursing
The paper written by Dal Molin et al. (2015) about the use of normal saline (NS) versus heparin solution to lock totally implanted venous access devices concludes that: “our study did not find significant evidence of a difference between heparin solution and saline solution, but it failed in demonstrating non-inferiority of saline solution” (Dal Molin et al., 2015). Two years before, Goossens et al. (2013) reported that “Normal Saline is a safe and effective locking solution in implantable ports if combined with a strict protocol for device insertion and maintenance”, as result of a randomized study where 802 patients were enrolled. This study confirmed the results found in a retrospective study conducted by Bertoglio et al. (2012) one year before. A reflection on that should be made before starting with an additional large prospective study as suggested by the authors of the last work. All these studies highlight that the incidence of occlusions in the normal saline arm varies from 3.7% (Goossens et al., 2013) to 6.9% (Dal Molin et al., 2015). In the retrospective study 6.2% of patients even experienced the removal of the port as a result of irreversible occlusion (Bertoglio et al., 2012). A deep reading of the methods shows that all investigators chose 10 ml of NS to wash ports excepted in case of transfusion or parenteral nutrition administration where, in one study (Goossens et al., 2013), 20 ml were administered at the end of them. Dal Molin et al. (2015) affirmed that they chose to wash port with 20 ml of NS, but they used syringe of 10 ml. In this way they did not produce a 20 ml positive pressure, moreover changing the syringe to enrich 20 ml of NS caused an interruption of the flushing. It could appear as a detail but in the study of Milani et al. (2016) the incidence of partial occlusion was 1% and no total occlusion was reported on 4057 observations using 20 ml of NS maintaining positive pressure. A possible explanation could be found in a mechanical mechanism. http://dx.doi.org/10.1016/j.ejon.2016.02.005 1462-3889/© 2016 Elsevier Ltd. All rights reserved.
Totally implanted venous access devices are composed by a catheter connected to a reservoir. When a blood sample is collected, blood flows from the vein to the collecting tube, passing through the catheter and filling up the reservoir where, if not adequately washed, little amounts of blood could remain facilitating the occlusions. Considering this aspect and the significant difference in occlusions incidence when 20 ml of normal saline are used instead of 10 ml, the reasonable conclusion could be that a syringe of 20 ml is necessary to obtain the adequate pressure useful to cause a swirl able to remove all residual blood. There is enough literature that investigates the better solution in the maintenance of ports but too little about nurses’ clinical reasoning on what is the best practice to flush the totally implanted venous access devices. It is possible that when interpreting the results, investigators focused on the variables considered relevant in the context of the study, neglecting other variables crucial for the process and not explicitly considered in the design (Cherubini et al., 2003). For many years, in the prevention of the totally implanted venous access devices occlusions, nurses flushed port with heparin learning that the solution inserted in the catheter acts in the prevention of occlusions. As Mazzocco and Cherubini (2010) affirmed, “the outcome of a previous single case can be overweighted in the process of making a later decision about a similar case, to the point that information on outcome alone can modify a decision that the health provider originally thought to be optimal, according to his or her experience and the available evidence”. Accordingly, the outcome “occlusion” is wrongly interpreted to judge the efficacy of the process. All studies discussed here could show that nurses and their practice are the decisive key in the prevention of the occlusions where the normal saline solution is safer and more effective when administered maintaining a 20 ml of continuous positive pressure. No potential conflict of interest relevant to this letter was reported. References Bertoglio, S., Solari, N., Meszaros, P., et al., 2012. Efficacy of normal saline versus heparinized saline solution for locking catheters of totally implantable longterm central vascular access devices in adult cancer patients. Cancer Nurs. 35
Correspondence / European Journal of Oncology Nursing 21 (2016) 272e273 (4), E35eE42. Cherubini, P., Mazzocco, K. e, Rumiati, R., 2003. Rethinking the focusing effect in decision making. Acta Psychol. 113, 67e81. Dal Molin, A., Clerico, M., Baccini, M., Guerretta, L., Sartorello, B., Rasero, L., 2015. Normal saline versus heparin solution to lock totally implanted venous access devices: results from a multicenter randomized trial. Eur. J. Oncol. Nurs. 19 (6), 638e643. Goossens, G.A., Jerome, M., Janssens, C., et al., 2013. Comparing normal saline versus diluted heparin to lock non valved totally implantable venous access devices in cancer patients: a randomized, non inferiority, open trial. Ann. Oncol. 24 (7), 1892e1899. Mazzocco, K., Cherubini, P., 2010. The effect of outcome information on health professionals' spontaneous learning. Med. Educ. 44 (10), 962e968. Milani, A., Mazzocco, K., Gandini, S., Pravettoni, G., Libutti, L., Zencovich, C., et al., 2016. Incidence and determinants of port occlusions in cancer outpatients: a prospective cohort study. Cancer Nurs. (in press).
273
Alessandra Milani* European Institute of Oncology (IEO), Milan, Italy University of Milan, Italy *
Cascina Brandezzata (IEO), Via Ripamonti 428, 20141 Milano, Italy. E-mail address: [email protected]. 18 January 2016
Contents lists available at ScienceDirect
European Journal of Oncology Nursing journal homepage: www.elsevier.com/locate/ejon
Correspondence
The maintenance of totally implanted venous access devices: When the difference is made by the nursing practice Correspondence about the paper “Normal saline versus heparin solution to lock totally implanted venous access devices: Results from a multicenter randomized trial” by Dal Molin et al. (EJON 19;2015:638e643)
Keywords: Flushing Heparin Indwelling catheter Normal saline Nursing
The paper written by Dal Molin et al. (2015) about the use of normal saline (NS) versus heparin solution to lock totally implanted venous access devices concludes that: “our study did not find significant evidence of a difference between heparin solution and saline solution, but it failed in demonstrating non-inferiority of saline solution” (Dal Molin et al., 2015). Two years before, Goossens et al. (2013) reported that “Normal Saline is a safe and effective locking solution in implantable ports if combined with a strict protocol for device insertion and maintenance”, as result of a randomized study where 802 patients were enrolled. This study confirmed the results found in a retrospective study conducted by Bertoglio et al. (2012) one year before. A reflection on that should be made before starting with an additional large prospective study as suggested by the authors of the last work. All these studies highlight that the incidence of occlusions in the normal saline arm varies from 3.7% (Goossens et al., 2013) to 6.9% (Dal Molin et al., 2015). In the retrospective study 6.2% of patients even experienced the removal of the port as a result of irreversible occlusion (Bertoglio et al., 2012). A deep reading of the methods shows that all investigators chose 10 ml of NS to wash ports excepted in case of transfusion or parenteral nutrition administration where, in one study (Goossens et al., 2013), 20 ml were administered at the end of them. Dal Molin et al. (2015) affirmed that they chose to wash port with 20 ml of NS, but they used syringe of 10 ml. In this way they did not produce a 20 ml positive pressure, moreover changing the syringe to enrich 20 ml of NS caused an interruption of the flushing. It could appear as a detail but in the study of Milani et al. (2016) the incidence of partial occlusion was 1% and no total occlusion was reported on 4057 observations using 20 ml of NS maintaining positive pressure. A possible explanation could be found in a mechanical mechanism. http://dx.doi.org/10.1016/j.ejon.2016.02.005 1462-3889/© 2016 Elsevier Ltd. All rights reserved.
Totally implanted venous access devices are composed by a catheter connected to a reservoir. When a blood sample is collected, blood flows from the vein to the collecting tube, passing through the catheter and filling up the reservoir where, if not adequately washed, little amounts of blood could remain facilitating the occlusions. Considering this aspect and the significant difference in occlusions incidence when 20 ml of normal saline are used instead of 10 ml, the reasonable conclusion could be that a syringe of 20 ml is necessary to obtain the adequate pressure useful to cause a swirl able to remove all residual blood. There is enough literature that investigates the better solution in the maintenance of ports but too little about nurses’ clinical reasoning on what is the best practice to flush the totally implanted venous access devices. It is possible that when interpreting the results, investigators focused on the variables considered relevant in the context of the study, neglecting other variables crucial for the process and not explicitly considered in the design (Cherubini et al., 2003). For many years, in the prevention of the totally implanted venous access devices occlusions, nurses flushed port with heparin learning that the solution inserted in the catheter acts in the prevention of occlusions. As Mazzocco and Cherubini (2010) affirmed, “the outcome of a previous single case can be overweighted in the process of making a later decision about a similar case, to the point that information on outcome alone can modify a decision that the health provider originally thought to be optimal, according to his or her experience and the available evidence”. Accordingly, the outcome “occlusion” is wrongly interpreted to judge the efficacy of the process. All studies discussed here could show that nurses and their practice are the decisive key in the prevention of the occlusions where the normal saline solution is safer and more effective when administered maintaining a 20 ml of continuous positive pressure. No potential conflict of interest relevant to this letter was reported. References Bertoglio, S., Solari, N., Meszaros, P., et al., 2012. Efficacy of normal saline versus heparinized saline solution for locking catheters of totally implantable longterm central vascular access devices in adult cancer patients. Cancer Nurs. 35
Correspondence / European Journal of Oncology Nursing 21 (2016) 272e273 (4), E35eE42. Cherubini, P., Mazzocco, K. e, Rumiati, R., 2003. Rethinking the focusing effect in decision making. Acta Psychol. 113, 67e81. Dal Molin, A., Clerico, M., Baccini, M., Guerretta, L., Sartorello, B., Rasero, L., 2015. Normal saline versus heparin solution to lock totally implanted venous access devices: results from a multicenter randomized trial. Eur. J. Oncol. Nurs. 19 (6), 638e643. Goossens, G.A., Jerome, M., Janssens, C., et al., 2013. Comparing normal saline versus diluted heparin to lock non valved totally implantable venous access devices in cancer patients: a randomized, non inferiority, open trial. Ann. Oncol. 24 (7), 1892e1899. Mazzocco, K., Cherubini, P., 2010. The effect of outcome information on health professionals' spontaneous learning. Med. Educ. 44 (10), 962e968. Milani, A., Mazzocco, K., Gandini, S., Pravettoni, G., Libutti, L., Zencovich, C., et al., 2016. Incidence and determinants of port occlusions in cancer outpatients: a prospective cohort study. Cancer Nurs. (in press).
273
Alessandra Milani* European Institute of Oncology (IEO), Milan, Italy University of Milan, Italy *
Cascina Brandezzata (IEO), Via Ripamonti 428, 20141 Milano, Italy. E-mail address: [email protected]. 18 January 2016