Modulation of aldosterone release by epidural analgesia impacts brain natriuretic peptide: a link to stress cardiomyopathy? Pilot study

OBJECTIVE: Data pertaining to whether stress-induced aldosterone release is associated with cardiac disorders are lacking. This study was designed to compare whether the modulation of intra-operative aldosterone release by epidural analgesia had an effect on the brain natriuretic peptide (BNP) levels. DESIGN, PATIENTS, MEASUREMENTS: A study was pilot prospective, open label randomized one. Patients were randomized to one of two anaesthesia protocols: group 1 included 13 patients who received general anaesthesia, and group 2 included 12 patients who received combined general anaesthesia and epidural analgesia. Study protocol was by completed 25 male patients, median age 56 years, without significant comorbidities, who underwent radical cystectomy because of urinary bladder tumour. Serum aldosterone, BNP, cortisol (measured by radioimmunoassay), adrenocorticotropine hormone (ACTH) (by solid-phase ELSA), blood chemistry, complete blood count and vital signs were compared preoperatively, intra-operatively and at postoperative days (POD) 1 and 7. RESULTS: Hemodynamics was stable in both groups. Group 1 showed threefold serum aldosterone, (P = 0·001) 20-fold ACTH (P = 0·003) and twofold cortisol (P = 0·001) increases intra-operatively, unlike group 2. Both groups had a twofold BNP increase in POD 1 that remained above normal on POD 7 only in group 1 (P = 0·02; P = 0·019 vs group 2). CONCLUSION: Alleviation of aldosterone release by epidural analgesia modulated the postoperative serum BNP pattern in patients with a low risk for cardiac diseases who underwent noncardiac surgery.