Ferroterapia endovenosa en la optimización de la hemoglobina en el postoperatorio de cirurgía neoplásica colorrectal:

Abstract

Postoperative anemia after colorectal cancer surgery increases morbidity and mortality. Blood transfusions have numerous disadvantages and adverse effects. Clinical guidelines recommend intravenous iron supplementation before and / or after the intervention to reduce transfusion requirements, although there is no robust evidence in this regard. At the time of setting this project, two pharmacological options of IV iron were available in our hospital: iron sucrose for administration of repeated doses every 48 hours, and iron carboxymaltose that allows to administer high single doses and is more expensive. Iron sucrose was prioritized for sustainability reasons at the same time that a "Fast-track" program of early post-surgical discharge in colorectal surgery was implemented. The concern about possible underdosing in patients for whom early discharge prevented receiving the full fractioned dose, and its potential consequences, motivated the review of the available evidence. Because of the lack of comparative data between both iron IV options, a direct comparison was deemed necessary. The absence of previous data recommended to approach the project in two steps: a retrospective study to describe the usual practice and to support the design of the prospective comparison, and a comparative controlled clinical trial. The observational study included 159 patients who underwent surgery in 2013. After surgery for colorectal cancer, 87% of the patients had anemia, and only 34% of the patients who had an IV iron indication received it, with a mean dose of 467 mg. At 30 days after surgery, the prevalence of anemia was 49.7%. Then, a randomized open-label, parallel-group clinical trial compared two treatments: a fractioned dosing with 200 mg / 48 h of iron sucrose upt to cover iron deficiency, and followed by oral iron prescription at patient discharge, and a single iron carboxymaltose dose of 1g, to test whether the single dose improved hemoglobin concentration by 0.75 g / dL or more at 30 days after surgery, as compared to the fractioned dosing. We screened 373 patients of which 101 were included in the trial between September 2015 and May 2018. The iron sucrose regimen was incomplete in 90% of patients, with mean total doses administered of 556 mg vs 995 mg in the group carboxymaltose. The results showed no significant differences in the change of hemoglobin between days 1 and 30 postsurgical, with improvements in both groups about 2.5 g / dL. No differences were observed in a number of secondary efficacy variables. The null hypothesis of absence of differences could not be rejected. There were no adverse effects attributable to iron IV, nor differences in quality of life, although this assessment was made with numerous limitations. There were no differences in the number of transfusions, length of hospital stay or hospital readmissions. However, patients treated with iron sucrose had a higher infection rate than those treated with iron carboxymaltose, although in the context of multiple comparisons not adjusted for multipliciy of analyses. Apparently, the effect of preoperative optimization in patients with iron deficiency, prior to surgery, could be of greater importance than the dose of iron administered to anemic patients in the immediate postoperative period. In summary, we have established that both a fractioned regimen and a single intravenous iron administration regimen are effective in the treatment of postoperative anemia in colorectal cancer surgery. The observed results may question some key aspects of perioperative ferrotherapy.

Date of Award	11 Nov 2019
Original language	Spanish
Supervisor	Caridad Pontes Garcia (Director), Roser Vives Vilagut (Director) & Ignacio Jose Gich Saladich (Tutor)