Spirometry parameters in patients undergoing hemodialysis with bicarbonate and acetate dialysates

End-stage renal disease causes impairment of all body organs including the heart and the lung. The main problems in the afflicted patients are pulmonary edema due to increased permeability of the capillaries, intravascular and interstitial volume overload, hypertension, and congestive heart failure. These changes cause altered physiologic and mechanical function of the lungs and subsequently increase in airway resistance. We aimed to study the impact of hemodialysis on spirometry parameters.

In a cross-sectional study performed on 41 patients on maintenance hemodialysis, spirometry was done before and after the dialysis session. The patients were on either acetate or bicarbonate hemodialysis with the same method, dialysis machine, and duration of dialysis. Alterations in spirometry parameters including forced expiratory volume in the first second (FEV1), forced vital capacity (FVC), FEV1/FVC ratio, and maximal midexpiratory flow rate were determined and their relation with serum electrolytes, serum creatinine, blood urea nitrogen, and hemoglobin were analyzed.

Twenty-nine patients undergoing dialysis with bicarbonate dialysate and 21 on dialysis with acetate were compared. Improvement in spirometry parameters was only significant in patients undergoing dialysis with bicarbonate dialysate. All spirometry parameters showed significant increases in the bicarbonate group except for the FEV1/FVC ratio. Furthermore, significant increase in these parameters was only prominent in the men. Postdialysis weight reduction and laboratory indexes had no significant correlation with improvement of spirometry parameters.

Dialysis with bicarbonate dialysate causes significant improvement in spirometry parameters in men on maintenance dialysis. This effect might be independent of the effect of removing the volume overload by dialysis.