The nurse should first call the attention of the attending physician. Fentanyl administration for the next doses must be cancel.Respiratory depression is one of the adverse drug effects of fentanyl. Patient with altered respiration can affect the level of oxygen and carbon dioxide. Caution must be given in patients that have respiratory problems such as COPD, asthma and other. Patients with severe respiratory depression can be given analgesic antagonist such as naloxone.