Role 3 Treatment of Pain

Regional anesthesia procedures should be performed in a monitored setting where nursing staff is available to help with patient care and provide appropriate recovery services for the patients. The APMS (discussed extensively above) should maintain and provide input for standing orders to include:

- Continuous epidural and peripheral nerve catheter infusion and single injection epidural or intrathecal narcotics.
- Intravenous PCA Orders. Fentanyl, hydromorphone, and morphine are the narcotic agents of choice. (Meperidine (Demerol) is not an approved compound for repeated PCA dosing as the metabolite normeperidine reduces the seizure threshold.)

Low dose ketamine infusions have profound analgesic effects with very minimal side effects. The anti- inflammatory effects of ketamine may also attenuate the systemic inflammatory response seen in trauma.13,23,24 Ketamine binds the N-methyl-D-aspartate receptor and in addition to having direct analgesic properties, it also decreases the total dose of narcotics needed for adjuvant pain control.

Ketamine infusions should be made as follows:

- 250 mg of Ketamine in 250 ml of normal saline.
- For patients who are 70 kg or greater and less than 60 years old, start infusions at 10 mg per hour in the setting of acute and neuropathic pain.
- Patients > 60-year-old or <70kg should receive 100 micrograms/kg/hour of ketamine in the setting of acute or neuropathic pain.
- Custom orders may be titrated by the attending anesthesiologist or critical care physician.