Effect of hemodialysis on respiratory mechanics in acute kidney injury patients

Introduction: Hemodialysis (HD) is one treatment for acute kidney injury (AKI) patients. Studies have shown that this dialysis modality may lead to changes in pulmonary function with an impact on prognosis. The aim of our study was to evaluate changes in respiratory mechanics and oxygenation of AKI patients admitted to an intensive care unit who were undergoing intermittent mechanical ventilation (IMV) and daily HD. Methods: This prospective cohort study evaluated 94 AKI patients and 234 HD sessions. Pulmonary static compliance (Pcs), resistance (Rsr), and arterial partial pressure of oxygen and the fraction of inspired oxygen (PaO 2 /FiO 2 ) ratio were assessed during the initial three-day period of daily HD therapy. Findings: Psc increased progressively during HD sessions, from 39.4 ± 21.4 mL/cm H 2 O prior to the initial dialysis to 55.5 ± 25.2 at the end of the last dialysis during the study period (P = 0.04). Similarly, Rsr and PaO 2 /FiO 2 ratio also improved, from 11.1 ± 6.3 cm H 2 O/L/s prior to the initial dialysis to 8.8 ± 4.2 at the end of the last dialysis (P =0.0027) and from 228 ± 85 prior to the initial dialysis to 312.1 ± 111.5, P < 0.001, to the end of the last dialysis, respectively. Conclusion: This study showed that AKI patients undergoing IMV and daily HD improve their respiratory mechanics and oxygenation.