L Parra1, G Fita, C Gomar, I Rovira, J L Marín. 1. Department of Anaesthesiology, Hospital Clinic i Provincial, University of Barcelona, Barcelona, Spain.
Abstract
BACKGROUND: To determine the changes in magnesaemia in cardiac surgical patients submitted to cardiopulmonary bypass (CPB) and their influence on perioperative morbidity. SETTING: the cardiovascular surgery department of a university hospital. PATIENTS: 60 patients of both sexes, mean age 60+/-12 yrs, operated on consecutively for myocardial revascularization or valve replacement. INTERVENTIONS: 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.
BACKGROUND: To determine the changes in magnesaemia in cardiac surgical patients submitted to cardiopulmonary bypass (CPB) and their influence on perioperative morbidity. SETTING: the cardiovascular surgery department of a university hospital. PATIENTS: 60 patients of both sexes, mean age 60+/-12 yrs, operated on consecutively for myocardial revascularization or valve replacement. INTERVENTIONS: 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: S Dittrich; J Germanakis; I Dähnert; B Stiller; H Dittrich; M Vogel; P E Lange Journal: Intensive Care Med Date: 2003-05-28 Impact factor: 17.440