title: Evaluation of intradialytic hypotension using impedance cardiography.
abstract: BACKGROUND
  Hypotension during hemodialysis is frequent in patients with cardiovascular disease who have a limited physiological compensatory response. Recent advances in technology allow non-invasive monitoring of cardiac output and derived hemodynamic parameters. This prospective study evaluated episodes of intradialytic hypotension using clinical data and continuous non-invasive hemodynamic monitoring by impedance cardiography.
  
  
  METHODS
  Forty-eight chronic hemodialysis patients, with prevalence for intradialytic hypotensive episodes, underwent evaluation with non-invasive impedance cardiography (Physioflow) before, during and after a regular dialysis session.
  
  
  RESULTS
  During continuous non-invasive cardiac monitoring, a fall of systolic arterial blood pressure of 20% or more at least once during hemodialysis was detected in 18 patients (37.5%)--thereafter identified as the "Unstable" group. In 30 patients--thereafter called the "Stable" group, the blood pressure did not change significantly. During hypotension, a decrease in cardiac output was found in 11 of the 18 unstable patients, and a significant fall in peripheral resistance in the remaining 7. End-diastolic filling ratio was significantly lower in the unstable group. The most significant predictors associated with intradialytic hypotension were the presence of ischemic heart disease (P = 0.05), and medication with beta blockers (P = 0.037) and calcium channel blockers (P = 0.018).
  
  
  CONCLUSIONS
  Hemodynamic changes in dialysis patients with hypotensive episodes included decreased cardiac output or decreased peripheral resistance. A lower end-diastolic filling ratio may be regarded as a marker for reduced preload in these patients. Non-invasive impedance cardiography may be used to evaluate risk factors for hypotension in dialysis patients.
authors.affiliation: Medical Intensive Care Unit, Division of Medicine, Hadassah-University Medical Centre, Ein Kerem, Jerusalem 91120, Israel.
authors.forename: Abed
authors.initials: A
authors.lastname: Bayya
authors.forename: Dvora
authors.initials: D
authors.lastname: Rubinger
authors.forename: David Michael
authors.initials: DM
authors.lastname: Linton
authors.forename: Sigal
authors.initials: S
authors.lastname: Sviri
mesh_terms: D000319:Adrenergic beta-Antagonists / Q000009:adverse effects; D002121:Calcium Channel Blockers / Q000009:adverse effects; D002307:Cardiography, Impedance; D005260:Female; D006439:Hemodynamics / Q000502:physiology*; D006801:Humans; D007022:Hypotension / Q000209:etiology* / Q000503:physiopathology*; D007676:Kidney Failure, Chronic / Q000628:therapy; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic / Q000379:methods; D017202:Myocardial Ischemia / Q000150:complications; D011446:Prospective Studies; D006435:Renal Dialysis / Q000009:adverse effects*; D018709:Statistics, Nonparametric
chemical_list: D000319:Adrenergic beta-Antagonists; D002121:Calcium Channel Blockers
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