[Changes in whole blood ionized magnesium concentration during cardiac surgery employing St. Thomas' cardioplegic solution].

BACKGROUND: Although there is growing evidence to suggest that magnesium supplementation to patients undergoing cardiac surgery is beneficial, the way to administer magnesium is not established. Moreover in Japan St Thomas' cardioplegic solution, containing a high level of magnesium is widely used and the effect of such magnesium-rich cardioplegic solutions on blood magnesium concentration has not been well defined. METHODS: We measured ionized magnesium concentrations (iMg) during cardiac surgery employing St Thomas' solution. Patients were divided into four groups. Group 1 patients were adults and group 2 were children, both of whom received St. Thomas' solution. Group 3 patients underwent cardiopulmonary bypass but did not receive any cardioplegic solution. Group 4 patients underwent off-pump coronary artery bypass grafting. RESULTS: In cardioplegia group (group 1 and 2) iMg was higher than the normal reference range at periods of rewarming, immediately postbypass, and at the end of the operation. iMg at immediately postbypass was related to the total amount of cardioplegic solution. In non-cardioplegia group (group 3 and 4) progressive decrease of iMg was observed throughout the operation. CONCLUSION: Because magnesium in cardioplegic solutions has substantial effect on perioperative iMg, it is crucial to measure iMg to avoid overdose of magnesium when magnesium-rich cardioplegic solutions are employed.

[Anesthetic management of a patient with lymphangioleiomyomatosis who developed respiratory failure post-operatively].

A 34-year old female underwent lung biopsy under video assisted thoracoscopic surgery for lymphangioleiomyomatosis (LAM). She had obstructive lung disease, and had a large amount of ascites. We did not treat her lung disease pre-operatively because her pulmonary symptom was not severe. During operation, anesthesia was uneventful even during one lung ventilation period. After surgery, she showed hypoxemia and fell into respiratory failure. We suspect that respiratory failure was induced by ascites in this case. Respiratory failure would have come from restrictive ventilatory impairment caused by a large amount of ascites in addition to the obstructive ventilatory impairment. Care should be taken on respiratory function in case of LAM with ascites during perioperative period.