Acute heart failure during spinal surgery in a boy with Duchenne muscular dystrophy.

EditorÐSchmidt and colleagues should be congratulated for their case presentation and the patient's good outcome. We appreciated the detailed discussion on Duchenne muscular dystrophy (DMD) and perioperative complications. It is striking that preoperative echocardiography may not re ̄ect the intraoperative ability of the diseased myocardium to respond to stressÐa situation we are quite often confronted with in clinical scenarios. The authors raise the question of which intraoperative monitoring should be used for detection of cardiac abnormalities and for adjusting therapy. From our point of view the patient was adequately monitored, at least at the beginning of the operation. Nevertheless, we are surprised that the high arteriovenous PCO2 difference of 15 mm Hg, 30 min after induction of anaesthesia (Fig. 2 of Case Report 1) was not mentioned in the discussion. Given a normal ventilatory situation, should this difference not be interpreted as a hallmark of early cardiac decompensation? Carried forward to anaesthetic practice generally, an increased arteriovenous PCO2 difference demands clari®cation, and should be the trigger for more invasive haemodynamic monitoring such as transoesophageal echocardiography, pulmonary artery catheterization or pulse contour analysis.