Discussion
dialysis-induced hypotension, hypovolemia, hemodialysis-induced hypotension, intradialytic hypotension
COMPLICATION OF HEMODIALYSIS, INTRADIALYTIC HYPOTENSION, VASODILATION, HEREDITARY ANGIOEDEMA
In this pilot study, we found that bradykinin BThe lack of vasoconstriction in response to hypovolemia is one of the impaired responses during intradialytic hypotension. Previous studies suggest that vasopressin, nitric oxide, and adenosine are associated with the occurrence of intradialytic hypotension [Bradykinin is a potent vasoactive peptide that results from the cleavage of high molecular kininogen by tissue and plasma kallikreins and causes vasodilation through the activation of the bradykinin BIntradialytic hypotension is a common clinical complication of hemodialysis, and it is associated with increased morbidity and mortality [Bradykinin usually peaks within the first 15 min of hemodialysis, [We have not measured the clearance of icatibant by the dialyzer, however, vitamin B12 has similar biophysical properties compared to icatibant, such as molecular weight and water solubility. In this study, the KoA (dialyzer mass transfer area coefficient) for vitamin B12 was 312 ml/min (at blood and dialysate flow of 300 and 500 mL/min, respectively). Thus, some amount of icatibant may be cleared during hemodialysis and limit its effectiveness. For this reason, icatibant was continuously infused before and during hemodialysis. Nevertheless, further studies should evaluate the clearance of icatibant during hemodialysis.This study has some limitations: First, our study should be considered exploratory since our inclusion criteria did not specifically select patients with a documented history of hemodialysis-induced hypotension, and the primary objective of the study was to study mitochondrial function and blood pressure during hemodialysis, but not intradialytic hypotension. While our results are intriguing, future studies should target patients with a history of dialysis-induced hypotension to confirm our findings. Second, this study included young, predominantly male, and African American patients. Thus, the results of the study may not be generalized to a more diverse population of patients on hemodialysis. There were also numerous exclusion criteria that may limit the generalization of the results. Finally, while we used a cross-over design, our sample size is relatively small, and our results should be interpreted with caution.In conclusion, our study suggests that endogenous bradykinin contributes to the decrease in blood pressure during hemodialysis. Pharmacological therapies that block the effect of bradykinin or inhibit the activation of the kallikrein-kinin system, such as the ones approved for use in hereditary angioedema, represent potential novel treatments for the prevention of intradialytic hypotension.