Peritoneal membrane characteristics in patients on peritoneal dialysis.

Peritoneal dialysis (PD) is a well-established modality for treatment of patients with end-stage renal disease, giving excellent patient and technique survival rates. In Saudi Arabia, data collected by the Saudi Center for Organ Transplantation showed that in 2008, patients on PD accounted for a mere 4.8% of total patients on renal replacement therapy, including hemodialysis and renal transplantation. This study was conducted to identify the characteristics of membrane permeability in the Saudi population and to assess the role of various factors affecting solute transport across the peritoneal membrane. We followed up a total of 52 patients on Continuous Ambulatory Peritoneal Dialysis (CAPD) as well as Automated Peritoneal Dialysis (APD), being treated in the PD unit of the King Khalid University Hospital, Riyadh. There were 30 female and 22 male patients; 14 patients were using CAPD while 38 patients were on APD. The mean age of the patients was 50.5 years, with a range of 14-86 years. The average body mass index (BMI) was 27.1 kg/m² and the mean body surface area (BSA) of the study patients was 1.71 m². A standardized PET test was performed on all patients, 4-6 weeks after initiation of regular PD. The Kt/V and creatinine clearance measured 6-8 weeks after initiation of dialysis were 1.96 and 56.59 L/week, respectively. Residual renal function was assessed on the basis of daily urine output, using 24-hour urine collection. The mean serum urea con-centration was 16.91 mmol/L and mean serum creatinine was 702 µmol/L. According to the Peritoneal Equilibration Test (PET), 8% of the subjects belonged to the high trans-porter category, 44% patients belonged to the high-average transport group, 46% to the low-average category and 2% came in the low transporter category. Our study suggests that the patient characteristics and demographic para-meters seen in the Saudi population are comparable to those seen in other studies from the Middle East and worldwide, including data collected from Canada, New Zealand and Mexico.

Electrocardiography and serum potassium before and after hemodialysis sessions.

This study was undertaken to assess potassium level and electrocardiographic (ECG) changes post hemodialysis and whether fall in potassium level during dialysis may potentiate cardiac arrythemia. We studied 21 chronic hemodialysis (HD) patients who had their serum electrolytes measured before and immediately after dialysis session, and ECG performed at the same time. The patients included 14 females and 7 males with a mean age of 53.1+/-15.6 years and range from 26 to 81 years; 9 (43%) patients were diabetics. All the patients had been on dialysis for a minimum of 6 months each Pre-HD serum potassium levels had no correlation with any ECG parameters except a negative correlation with the T wave amplitude r=-0.5, p=0.021. ECG parameters significantly changed post-HD; the T wave amplitude decreased, and the R wave amplitude increased. A comparatively higher R wave significantly decreased the T to R wave ratio post dialysis. The QRS duration and QTc interval also increased significantly. The patients with post-HD serum potassium of < or = 3.5 -in comparison to those with levels > 3.5 mmol/L -had a higher R wave amplitude and a significantly less T to R wave ratio (11.8+/-9.7 vs 6.4+/-5.1, p=0.045 and 0.4+/-0.38 vs 1.0+/-0.97, p=0.049, respectively. In patients with serum potassium decrement of > 2.0 mmol/L, the T to R wave ratio decreased significantly, 0.32+/-0.21 vs 0.85 +/-0.26, p=0.023; The T wave amplitude decreased more than the rise in R wave. Multiple regression analysis did not reveal any relationship of pre or post HD ECG changes and serum potassium, serum calcium or net change in serum potassium post-HD. We conclude that post-HD serum potassium decrement results in a decrease in T to R wave ratio on ECG; this change may have an arrhythmogenic potential.