[From dialysate temperature to thermal balance].
The observations concerning the role of temperature in cardiovascular (CV) stability date back to the early 1980s. Since then, many studies have corroborated the original findings on the hemodynamic benefits of what is known as 'cold' as opposed to 'warm' or standard hemodialysis (HD). While the assumptions and conclusions remain fully valid, more recent experience has led to a review of the way the treatments have been defined. The fact that the patient gains or loses heat is not only the consequence of dialysis fluid temperature, but is the result of the interrelationships between dialysis-related factors and patient characteristics. Among the former, blood flow, arterovenous temperature difference in the extracorporeal blood, length and layout of the hematic lines, environmental temperature, and a possible cytokine-mediated pyrogenic effect are all factors that, directly or indirectly, can decisively influence the thermal balance of the dialysis session. Among the latter, the greater the ultrafiltration (UF) rate the greater the buildup of body heat. Finally, there is a considerable variability in body temperature within and between individual uremic patients, and it is especially the subgroup of hypothermic patients who benefit from cold dialysis. These considerations have led to the conclusion that the thermal balance of the dialytic treatment should be tailored to the specific characteristics of the patient and should be adjusted automatically in the course of the dialytic treatment. On these grounds, it is preferable to define thermal variations induced by HD based on physiological effects induced in the patient. Therefore, dialytic treatments can be defined as isothermic, hypo or hyperthermic, depending on the variations in body temperature produced. Isothermic HD combines better benefits in terms of CV stability with fewer unwanted side effects. There are several commonly used therapies of symptomatic hypotension, but they have not been directly compared in the same group of patients. Comparison studies could offer a rational and a most effective approach to treating symptomatic hypotension.
Pizzarelli
F
F
U.O. Nefrologia Dialisi, Ospedale S.M. Annunziata, Florence. fpizzarelli@yahoo.com
D001831:Body Temperature / Q000502:physiology*; D002320:Cardiovascular Physiological Phenomena; D015314:Dialysis Solutions; D006801:Humans; D006435:Renal Dialysis / Q000379:methods*; D013696:Temperature
D015314:Dialysis Solutions