POST PRANDIAL BLOOD PRESSURE CHANGES IN PATIENTS WITH CHRONIC RENAL FAILURE DURING HEMODIALYSIS

Hypotension is a recognized complication of hemodialysis (HD), and many factors had been implicated one of which is eating before or during hemodialysis. Postprandial hypotension (PPH) was first recognized in 1977 by Seyer Hanseen. PPH is defined as decrease in systolic blood pressure or diastolic blood pressure of 20mmhg or more and 10mmhg or more respectively. The mechanisms of PPH are not fully understood but factors such as Impairment of baroreflex function, Inadequate postprandial increase in cardiac output, Impaired peripheral vasoconstriction, Insulin induced vasodilatation and Release of vasodilatory gastrointestinal peptides with attendant splanchnic blood pooling have been implicated. This study investigates the effect of food on blood pressure of patients during hemodialysis, with the view of proffering advice about meals during HD. The study was carried out over a six weeks period in St. Nicholas hospitals, Lagos, a privately owned 50-bedded hospital with a well developed renal transplant unit and a state of the art dialysis centre. There is also an efficient catering unit. Sixty one subjects were studied, 31 sessions being test session and 30 being controls. Of the 31 test sessions, 18 (58%) were males; and 13 (42%) were females while 18 (60%) of the controls were males and 12(40%) females, with age ranging from 15-79 years.  The nature of the study was explained to the patients and consent obtained. Those who wished to eat were given a standard meal of their choice. Before the start of HD or eating, initial BP was taken. Freizinus(R)  4008 HD machines and bicarbonate dialysate fluid were used for all patients. Blood pressure was monitored hourly for 4 hours. The patients who took antihypertensives before hemodialysis or had cause to take them during HD were excluded from the study. Those who did not eat were used as controls. There was Postprandial hypotension in 7 (23%); 6(86%) Diastolic Blood Pressure only, 1 (14%) both Systolic blood pressure and Diastolic Blood Pressure. All the patients were monitored for symptoms of weakness, dizziness, and chest pain.