Clonidine
DrugClonidine will be administered to preterm infants in need of analgesia and sedation; either as the primary drug for comfort and light sedation or as an "add-on" drug to opioids according to an algorithm based on pain and sedative scoring results. Opioids are mostly given to postoperative patients. These drugs (morphine or fentanyl) will not be studied, but a baseline PK sample will be taken to correlate to the baseline aEEG.