To the Editor,
Ischaemic colitis (IC) is a disease with an increasing incidence in haemodialysis (HD) patients, due to their changing profile (significantly older, with more cardiovascular disease and with increased survival in relation to the past)1. Despite the fact that IC can be secondary to vascular thrombosis or mesenteric vasospasm, the most frequent aetiology in HD patients is low output, which occurs during the session usually as a consequence of a lowering of blood pressure.
The case published by Gutiérrez-Sánchez et al.2, despite concerning a patient who had only been on HD for two months, presented many of the classic characteristics of patients with non-occlusive ischaemic colitis: high vascular risk patient with hypotensive episode who developed rectorrhagia and abdominal pain2. In the study recently published by our group involving the most cases of non-occlusive IC in HD, the factors associated with suffering this disease were older age, diabetes mellitus (DM), cardiovascular history (such as peripheral vascular disease), time on dialysis and resistance to erythropoietin. This last parameter is shown to be an independent predictor in multivariate analysis (together with DM and time on HD), demonstrating the association of this symptom with inflammation and, consequently, with atherosclerosis3. In a published study that included incident patients on dialysis (HD and peritoneal dialysis), the risk factors associated with suffering from non-occlusive IC were similar, apart from time on dialysis. However, on studying the various techniques, the authors found that the patients on peritoneal dialysis had a 1.5 times increased risk of suffering from this condition, despite being younger and having less comorbidity, which they associated with exposure to solutions with a high dextrose content4.
In this case series, the authors found 80 % mortality; this contrasts to our study in which mortality in the acute episode was 59 %. However, we performed a case-control study with patients who survived the acute episode over an average of 56 months (± 69). We found that the patients with non-occlusive IC had significantly lower survival, attributable to the condition being the result of these patients’ high cardiovascular risk. In fact, the causes of death were divided into infectious and cardiovascular. To date, the only study that compared survivors of non-occlusive IC with patients on HD was that by Bassilios et al., which showed identical survival in both groups, probably because it only included in the analysis those patients who survived more than three months5.
As regards treatment, as was the case in the abovementioned study, it is usual to administer wide-spectrum antibiotic therapy and have a wait-and-see approach; surgery is opted for in the minority of cases (only 33 % in our study), which is likely due to the patients’ profile (elderly, with cardiovascular risk, etc.). In fact, our results only revealed significant differences in age (younger) when we compared candidates for surgery with those in which a conservative approach was maintained. Previous studies have shown that the delay in carrying out surgery following diagnosis is associated with an increase in mortality6.
As a result, it seems reasonable to establish a more conservative ultrafiltration profile in patients at high risk of suffering from non-occlusive IC, due to its harmful consequences in HD patients.
Conflicts of interest
The authors declare that they have no conflicts of interest related to the contents of this article.
