title: Plasma magnesium in patients submitted to cardiac surgery and its influence on perioperative morbidity.
abstract: BACKGROUND
  To determine the changes in magnesaemia in cardiac surgical patients submitted to cardiopulmonary bypass (CPB) and their influence on perioperative morbidity.
  
  
  METHODS
  
  
  
  METHODS
  the cardiovascular surgery department of a university hospital.
  
  
  METHODS
  60 patients of both sexes, mean age 60+/-12 yrs, operated on consecutively for myocardial revascularization or valve replacement.
  
  
  METHODS
  plasma Mg2+ levels were measured preoperatively, during CPB, postCPB and throughout the first 24 hrs after operation. Preoperative plasma Mg2+ levels of these patients were compared with those of 15 non-cardiac surgical patients and 11 healthy volunteers.
  
  
  RESULTS
  Mean values of Mg2+ similar in the three populations although in the group of cardiac patients the number of hypomagnesaemic patients was significantly higher (16 patients=26.6%). In these 16 patients, preoperative hypomagnesaemia had a statistically significant relationship with the preoperative treatment with beta-blockers and previous history of arrhythmias (p<0.05). A progressive statistically significant decrease of Mg2+ was observed throughout the surgery that remained low at 24 hours postoperatively (p<0.05). Normomagnesemic patients needed significantly more shocks and electrical energy to obtain heart defibrillation after CPB. The incidence of both postoperative arrhythmias and postoperative low cardiac index (<2.5 L.m2) was statistically significantly more frequent in hypomagnesaemic patients (p<0.05).
  
  
  CONCLUSIONS
  Preoperative hypomagnesaemia was more frequent in this small sample of cardiac surgical patients than in non-cardiac surgical patients and was related to preoperative treatment with b-blockers. Hypomagne-saemia caused by CPB persisted 24 hrs after operation and was associated with higher incidence of both postoperative arrhythmias and low cardiac index.
authors: Department of Anaesthesiology, Hospital Clinic i Provincial, University of Barcelona, Barcelona, Spain.
authors: L
authors: L
authors: Parra
authors: G
authors: G
authors: Fita
authors: C
authors: C
authors: Gomar
authors: I
authors: I
authors: Rovira
authors: J L
authors: JL
authors: Marín
mesh_terms: D000319:Adrenergic beta-Antagonists / Q000627:therapeutic use; D000328:Adult; D001145:Arrhythmias, Cardiac / Q000097:blood / Q000209:etiology / Q000628:therapy; D002302:Cardiac Output; D006348:Cardiac Surgical Procedures; D002315:Cardiopulmonary Bypass; D004554:Electric Countershock; D005260:Female; D006801:Humans; D007431:Intraoperative Complications / Q000097:blood* / Q000628:therapy; D008274:Magnesium / Q000097:blood*; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000097:blood*; D012121:Respiration, Artificial
chemical_list: D000319:Adrenergic beta-Antagonists; D008274:Magnesium