INS and pneumonia: Important postoperative complications probably occurring independent of fluctuations in plasma sodium concentration were meningitis (n = 4), septicemia (n = 2), pneumonia (n = 1), cellulitis (n = 1), urinary tract infection (n = 3), fever of unknown origin treated with antibiotics (n = 4), postoperative anemia requiring (multiple) blood transfusion(s) (n = 2) and hyperglycaemia requiring insulin therapy (n = 2).