Title:
IS HYPERTENSION OR HYPOTENSION THE TRUE PROBLEM IN PATIENTS ON EXTRACORPOREAL DIALYSIS (RDT)?

GIOVANNI CALABRESE¹ ;GIOVANNI CALABRESE¹ ;GIOVANNI CALABRESE¹ ;GIOVANNI CALABRESE¹

1. RENAL UNIT - OSPEDALE S. SPIRITO - CASALE MONFERRATO -ITALY

E-mail address corresponding author:
dialisi@asl21.piemonte.it

Background:
Arterial hypertension (systolic BP>150 or diastolic BP>85 mmHg) is estimated to affect 75% of RDT patients and to be controlled adequately in only 30%. These data prompted us to evaluate the behaviour of BP in the population on extracorporeal RDT for at least 4 months in our Unit.

Methods:
All patients (n 71, F 29, age 66±15 yrs, BW 70±15 kg, dialytic age 65±58 mo) underwent on-line HDF, 47 (66%) in postdilution (exchanging 18±2 l/session) and 24 (34%) in predilution mode (27±6 l/session) using 1.4, 1.7 or 2.1 m2 high flux Polyamide m. QB was 300-400, QD 500 ml/min, session duration 260±13 min, 3 times/wk. 14 pts (20%) were diabetic, 9 pts (13%) had a residual diuresis and received furosemide (1±0.5 g) in the interdialytic days. Dialysate Na level (136±3 mMol/l, range 131-143) was adjusted inversely to BP, however with the strict goal of avoiding thirst. UF was arranged in order to achieve the targetted dry BW, which was reevaluated frequently; with this goal 5 pts underwent 4 sessions/wk for 1 or 2 weeks before the present observation. The pts were strongly recommended to follow a poor-salt diet, to limit fluid intake based upon thirst, and to avoid soft drinks. In 12 pts (17%) carvedilol (12.7 ± 8 mg/day) was given to correct hypertension. Supine pre-postdialytic (BD, AD) BP was evaluated at each session during one winter month period.

Results:
No patient complained of thirst. The interdialytic weight gain was 3.1±0.9% of BW, being > 4% (4.3±0.2) in 10 pts (14%). Predialytic systolic BP was “high” (BD 161±7 / 78±6, AD 134±11 / 66 ±5 mmHg) in 8 pts (11%), 3 of whom were diabetic, 5 older than 80 yrs (84±1) and 3 on antihypertensive therapy; BP was normal (BD 134±8 / 72±6, AD 122±13 / 66±8) in 42 pts (59%), 9 of whom were on therapy; it was “low” (BD 110±7 / 60±5, AD 104±10 / 57±7) in 21 pts (30%). In the 12 pts on therapy, BP was: BD 143±12 / 79±3, AD 136±11 / 74±6.

Conclusion:
In RDT patients hypertension can be prevented or corrected with the achievement and strict control of dry BW obtained by adjusting sodium in the dialysate and extracellular fluid volume, whereas an emerging problem is the high prevalence of critical pts with low BP (predialytic systolic BP < 120 mmHg).

Subject:
Complications

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