Abstract:

Objective To explore the association between plasma volume and blood pressure during hemodialysis in patients undergoing chronic hemodialysis. Methods Thirty-six patients undergoing chronic hemodialysis were divided into normotensive group (n=16) and hypertensive group (n=20) according to blood pressure before hemodialysis. The blood pressure and body weight before hemodialysis and after hemodialysis were recorded, and serum total protein concentrations were measured to determine the changes of plasma volumes (△PV). Statistical analysis was performed with SPSS 13.0 software. Results In normotensive group, the systolic pressure was (123.3±19.9) mmHg (1 mmHg=0.133 kPa) before hemodialysis and (122.3±27.0) mmHg after hemodialysis, the diastolic pressure was (69.6±9.2) mmHg before hemodialysis and (70.9±17.0) mmHg after hemodialysis, and there was no significant difference between systolic pressure and diastolic pressure before hemodialysis and those after hemodialysis (P>0.05). During hemodialysis in normotensive group, the change of body weight was (2.7±1.4) kg, and △PV was (14.7±10.8)%. In hypertensive group, the systolic pressure was (162.6±16.2) mmHg before hemodialysis and （148.2±31.1）mmHg after hemodialysis, the diastolic pressure was (86.6±9.6) mmHg before hemodialysis and (82.1±14.4) mmHg after hemodialysis, the systolic pressure after hemodialysis was significantly lower than that before hemodialysis (P<0.05), while there was no significant difference between diastolic pressure before hemodialysis and that after hemodialysis (P>0.05). During hemodialysis in hypertensive group, the change of body weight was (3.2±1.3) kg, and △PV was (20.4±14.4)%. Correlation analysis revealed that blood pressure before hemodialysis and after hemodialysis in hypertensive group and normotensive group was not significantly related to △PV and changes of body weight during hemodialysis (P>0.05). Conclusion During hemodialysis, changes in plasma volume do not influence changes in blood pressure before hemodialysis and after hemodialysis, and reduction in body weight is insufficient to reflect the changes of plasma volume and may be of limited effect to predict the changes in blood pressure before hemodialysis and after hemodialysis.

Key words: chronic hemodialysis, plasma volume, blood pressure, body weight