Complications of Regional Anesthesia Nabil M Elkassabany MD MSCE Assistant Professor Director; Orthopedic Anesthesia Section Department of Anesthesiology and Critical Care University of Pennsylvania Health System
Clin Orthop Relat Res. 1997 Nov;(344):188-206. Update on nerve palsy associated with total hip replacement. Schmalzried TP , Noordin S , Amstutz HC . J Bone Joint Surg Am. 1991 Aug;73(7):1074-80. Nerve palsy associated with total hip replacement. Risk factors and prognosis. Schmalzried TP , Amstutz HC , Dorey FJ .
Femoral nerve block before TKA is not a harmless intervention. We recommend postoperative protocols be modified for patients who have FNB to account for decreased quadriceps function in the early postoperative period, which can lead to falls .
The effects of femoral nerve blockade in conjunction with epidural analgesia after total knee arthroplasty
29% of patients who received FNB had buckling
because of decreased quadriceps strength, whereas only 3% of patients who did not receive FNB had buckling
YaDeau JT et al, Anesth Analg. 2005 Sep;101(3):891-5
Falls associated with lower-extremity-nerve blocks: a pilot investigation of mechanisms.
Muraskin SI , Conrad B , Zheng N , Morey TE , Enneking FK
Anesth Analg. 2010 Dec;111(6):1552-4. Epub 2010 Oct 1. The association between lower extremity continuous peripheral nerve blocks and patient falls after knee and hip arthroplasty. Ilfeld BM , Duke KB , Donohue MC .
incidence of severe neurologic injuries of 4.3% after 417 total shoulder arthroplasty procedures
Only 11% were related to the anesthetic technique whereas the remaining 89% were a result of the surgical procedure
J Shoulder Elbow Surg. 1996 Jan-Feb;5(1):53-61 . Neurologic complications after total shoulder arthroplasty. Lynch NM , Cofield RH , Silbert PL , Hermann RC . Department of Orthopedic Surgery, Mayo Clinic and Mayo Foundation, Rochester, Minnesota, USA. Three hundred sixty-eight patients underwent 417 total shoulder arthroplasties between 1975 and 1989. Seventeen patients with 18 operated shoulders had a neurologic deficit after surgery.
We found reports of fourteen shoulders that had a complication involving the peripheral nerve or the brachial plexus following total shoulder-replacement arthroplasty. Most of these injuries involved a neurapraxia, and non-operative treatment yielded good results. However, in two shoulders, the mechanism of neural injury involved a laceration of the axillary nerve, which occurred in a heavily scarred operative field. While most of these complications involved the axillary nerve (six shoulders), injury of the ulnar nerve (three shoulders), the musculocutaneous nerve (two shoulders), the median nerve (one shoulder),and the brachial plexus (two shoulders) was also reported. Seven of these injuries resolved completely, two resolved incompletely, one did not resolve at all,and the status of four was not mentioned .
. Neuropraxic lesions, which damage the myelin sheath but preserve the axon, are typically associated with compressive or stretch injuries and are perhaps more likely to resolve.
Conversely, if the axon is completely disrupted, recovery is slower and more likely to be incomplete.
The double crush theory
Nerve injury theory suggests that more than 1 insult is often necessary to cause damage. Peripheral nerve injury appears to require the breach of connective tissue barriers such as the perineurium that surrounds individual nerve fascicles and protects them from the external mi-lieu. Disruption of the perineurium from needle or catheter trauma is remarkably difficult to accomplish
. Animal studies and experience with ultra-sound-guided nerve localization has shown that nerves tend to move away from approaching needles. When nerves are impaled, the needle may pass harmlessly into or through connective tissue, which constitutes up to 70% of a nerve's cross-sectional area.
However, if the fascicle is penetrated, neurons are exposed to local anesthetics that can cause time- and concentration-dependent injury. Vasoconstrictors play a role by limiting local anesthetic clearance and thereby enhancing the time-dependent component of injury. Decreased neural blood flow from edema or mass effect can also potentiate cytotoxicity.
Sunderland : Proposed a five- grade classification system
Axontomesis:. Neurotemesis Neuropraxia
Seddon Sunderland Structural and functional processes Neuropraxia 1 Myelin damage, conduction slowing Axonotmesis 2 Loss of axonal continuity, endoneurium intact, no conduction 3 Loss of axonal and endoneurial continuity, perineurium intact, no conduction 4 Loss of axonal and endoneurial and perineural continuity, epineurium intact, no conduction Neurotmesis 5 Entire nerve trunk separated; no conduction
Fanelli et al reported paresthesias in 14% subjects.
Univariate analysis failed to demonstrate paresthesia as a risk factor.
Nerve stimulator and multiple injection technique for upper and lower limb blockade.: Failure rate, Patient acceptance, and neurologic complications. Fanelli G et al; Anesthesia Analgesia: 1999 : 88: 847-52.
Can pain or paresthesias be used to prevent neurologic injury .
Auray et al found that neurologic injuries occurred after paresthesias ensued even though the injection was stopped when pain was reported.
Serious complications related to regional anesthesia.: results of a prospective survey in france.Auroy Y et al; Anesthesiology. 1997: 87,479-86
Never inject local anesthetic when abnormal pressure on injection is present.
Never inject when patient complains of severe pain or has a withdrawal reaction.
Never inject when there is abnormal resistance.
Vasoconstructive agent Least toxic drug Recommended doses Site of injection Resuscitation equipment And drugs Monitoring Avoid forceful and Fast injections Frequent aspiration Verbal contact Slow injection Precautions
Evaluation of Nerve Injury after Regional Anesthesia
Weinberg et al ----- Intravenous lipid infusion in rats
Increased the dose of bupivacaine to produce asytole.
Successfully resuscitated all dogs with lipid infusions following bupivacaine induced cardiac arrest.
1 ml/kg bolus of lipid emulsion 20% over 1 min.
The dose can be repeated every 3-5 mins upto a maximum of 3 ml/kg.
At conversion to sinus rhythm continue the infusion at 0.25 ml/kg/min until hemodynamic recovery.
Weinberg G, VadeBoncouer T, Ramaraju GA, Garcia-Amaro MF, Cwik M: Pretreatment or resuscitation with a lipid infusion shifts the dose-response to bupivacaine-induced asystole in rats. Anesthesiology 1998; 88:1071-5
Rosenblatt et al reported the first case of successful resuscitation after a prolonged cardiac arrest following interscalene block.
Successful use of 20% lipid emulsion to resuscitate a patient after a presumed bupivacaine related cardiac arrest. Rosenblatt et al Anesthesiology July 2006 ; Volume 105( 1); 217-18