- Contraindication for a continuous peripheral nerve catheter (allergy to local anesthetic, infection at site of injection, elevated coagulation times (international normalized ratio (INR)>1.5, partial thromboplastin time (PTT)>38; these values are drawn as part of routine standard of care and those values will be checked prior to initial catheter insertion), therapeutic dosing of anticoagulation medication, moderate to severe head injury and moderate to severe traumatic brain injury