Chapter 54. Regional Anesthesia in Patients with Trauma
Which of the following is true regarding the use of continuous perineural catheters after trauma?
A. Continuous catheters should be removed at 48 hours to prevent infection.
B. Catheters can be used for both background analgesia and for surgical anesthesia.
C. Infection rates for catheters may depend on the type of catheter used.
D. The maximum combined rate of 0.2% ropivacaine for all catheter infusions should not exceed 8 mL/hr.
B is correct. Continuous perineural catheters are an excellent technique for analgesia following polytrauma. They can provide targeted analgesia that is virtually devoid of side effects for days to weeks. In patients who are returning to the operating room every 2–3 days for repeated procedures (eg, debridements), the catheter(s) can be maintained with a background infusion of a low- concentration solution for analgesia (eg, 0.1%–0.2% ropivacaine), and then bolused with a higher-concentration solution (eg, 0.5% ropivacaine) for surgical anesthesia.
A is incorrect. Catheters may be left in place for days to weeks, depending on the indication, the anatomical site, and the estimated risk of infection vs. benefit of the catheter. In trauma patients, the risk for infection starts to rise at about 48 hours, but the overall risk is still low with only 0%–3% of all catheters showing evidence of infection.
C is incorrect. Catheter type may play a role in the development of infection. Lai et al reported a case series of two superficial and four deep infections, in which the deep infections requiring operative incision and drainage were associated with stimulating catheter use. The authors hypothesized that repetitive movements of a catheter with an internal metal coil could result in microhematoma formation, providing a rich culture medium for hematogenously spread bacteria. In trauma patients it may be prudent to use catheter kits that lack a coiled metal tip.
D is incorrect. Common clinical practice, supported by long-term studies in military patients receiving multiple infusions, is to limit the overall rate of 0.2% ropivacaine to approximately 12–14 mL/hr. This is clearly patient- and clinician-dependent and individual circumstances will dictate clinical practice, but 14 mL/hr appears to be a safe overall limit.
The femoral head is innervated by all of the following except:
D. Lateral femoral cutaneous nerve
D is correct. The femoral head is not innervated by the lateral femoral cutaneous nerve. The lateral femoral cutaneous ...