Fig. 7.
Burn injury–induced tolerance to narcotics and sedatives. A 17-yr-old male sustained 90% flame burn injury requiring mechanical ventilation, multiple surgeries, and anesthetics. The graph indicates the mg · kg−1 · h−1 doses of morphine and midazolam administered over time after burn starting from week 1 to week 25. At one stage, the intravenous morphine and midazolam doses required exceeded 55 mg/hr of each. During procedures (e.g., dressing changes) additional doses of ketamine, dexmedetomidine, fentanyl, and/or propofol were administered pro re nata. More recently, when the doses of morphine and midazolam exceed 0.5 ml · kg−1 · h−1, we institute dexmedetomidine or ketamine infusions as sedative and change the opioid from morphine to fentanyl or vice versa (see also table 5).