Inhaled sedation in acute brain injury patients

Editor—Thanks for the chance to respond to the letter by Badenes and Bilotta. We appreciate their interest in our article1 and fully agree that tight management of the arterial partial pres sure of carbon dioxide ðPaCO2 Þ is crucial for avoiding increases in intracerebral pressure (ICP) resulting from hypercapnic vasodila tory effects. However, in our study increases in ICP have occurred not only in response to PaCO2 increases, but also independently, and at times these were fairly delayed after switching to the anaesthetic conserving device (ACD).1 Prompt increases in ICP are usually not expected after a more gradual increase in PaCO2 , but rather after sudden increases of PaCO2 , which might indeed occur directly after switching to the ACD in the absence of com pensatory mechanisms