Narcotic Analgesics
Posted by admin on November 18th, 2009Narcotic analgesics have been the traditional mainstay of postopera¬tive pain control. However, before ordering a narcotic, the physician should consider its effect and side effects. The same dose given to a young adull and an older adult will have a stronger effect on the older one. In older patients, important clinical side effects are usually dose related and include sedation, confusion, respiratory depression, and constipation. Despile these concerns, by far the most common error in narcotic use is undermedication.
Intramuscular injections produce initially high plasma drug levels that can cause undesirable side effects; then the levels rapidly decline, lead¬ing to <i recurrence of pain. Thus, patients are alternately overdosed and uncomfortable. In an alerl older person, meticulous titration of nar¬cotic in the recovery room followed by patient-controlled analgesia pro¬vides excellent pain relief. Patient-controlled analgesia provides a more stable blood level of medication, avoiding the roller-coaster effects of IM dosing.
Unfortunately, not every elderly patient is a candidate for patient-controlled analgesia. A confused or demented patient cannot safely or effectively use this method. If regional techniques and nonsteroidal ?inli-inflammatory drugs are ineffective or inappropriate, a continuous narcotic infusion may be useful. Fentanyl is an appropriate choice be¬cause of its relative lack of hemodynamic side effects. However, hepatic clearance of the drug is decreased in the elderly. Also, the drug is lipophilic, and Ihe increased proportion of body fat in the elderly leads to an increased volume of distribution. These factors increase the elimination lime in the elderly. Because the volume of distribution and clearance of a drug cannot he precisely determined for an individual patient, the proper loading dose and infusion rale must be estimated. In the recovery room, patienlscan be given fentanyl 15 to 25 ?g IV q 5 min until the desired analgesic effect is reached. The goal is to avoid exces¬sive sedation or respiratory depression while maintaining blood pres¬sure and pulse within acceptable limits. Once a patient is made com¬fortable with a loading dose of I’cnlanyf in the recovery room, an infusion can be started at ! ^g/kg/h. The patient should then be moni¬tored in the recovery room for at least 2 h, so that the infusion can be adjusted. On the surgical unit, hourly nursing assessments of vital signs, respirations, mental status, and arousability should be per¬formed. Often, such intense monitoring is available only in a step-down or intensive care unit
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