Lipid rescue for treatment of delayed systemic ropivacaine toxicity from a continuous thoracic paravertebral block

Abstract

A 66-year-old man underwent a left minithoracotomy for pleural biopsies and thoracentesis. A left T3 paravertebral catheter was placed prior to induction of general anaesthesia, and a total of 20 mL of bupivacaine 0.25% administered. Postoperatively, ropivacaine 0.2% infusion was commenced at 10 mL/hour. Thirty-seven hours after the initial block, the patient developed convulsions without loss of consciousness. The ropivacaine infusion rate was unchanged and no further boluses had been given. He reported of perioral tingling, a burning sensation in his legs and penis and agitation. Ropivacaine infusion was ceased and a bolus of lipid emulsion (Intralipid 20%) administered, followed by an infusion. His symptoms (aside from mild agitation) resolved within an hour of cessation of the local anaesthetic and commencement of lipid rescue. The total serum concentration of ropivacaine during the event was 2.1 mg/L compared with a published toxic level of 2.2 mg/L in healthy human volunteers.

Local Anesthetic Systemic Toxicity

“…Local anesthetic systemic toxicity events occurred in the: hospital (80%), office (11%), 12,19,33 and at home (9%). 6,28 In the hospital setting, 67% occurred in the operating room (OR), 14% in postanesthesia recovery unit (PACU), 8% on the wards, 13,21,22 8% in the emergency department, 5,17,37 and 3% (1 case) in the intensive care unit. 20…”

“…5,9,11,17,23,[32][33][34] The remaining cases resulted from neuraxial (13%: 4 of the 6 were epidural, 2 were described specifically as caudal injections), 16,20,26,29,30,38 paravertebral blocks (8.5%), 15,21,22,30 lower (8.5%) 6,7,13 and upper (8.5%) 6,31,36,39 extremity blocks, head and neck blocks (8.5%) (maxillary nerve, peribulbar), 14,19 topical, 28,35,37 transabdominis plane blocks, 8 and intravenous administration. 18 Seven cases (15%) involved continuous infusions of local anesthetic.…”

“…18 Seven cases (15%) involved continuous infusions of local anesthetic. 6,13,20,21,30 The block types associated with LAST are summarized in Figure 1.…”

“…There were 5 cases (11%) with onset of LAST ranging from 24 hours to 4 days, all involving continuous infusions of local anesthetic (interscalene, femoral/sciatic (2), epidural, paravertebral). 6,13,20,21 Presenting Features…”

“…Isolated CNS presenting features occurred in 45% (21/47), followed by combined CNS/CV toxicity 32% (15/47) and CValone 23% (11/47). Among the subgroup (15 of 47 cases) that had combined toxicity, CNS signs occurred first in 12 (75%) of the patients, 5,7,11,12,14,17,21,24,36,37,39 and CV signs occurred first in 3 (25%). 9,25,28 In 1 of these 3 cases, the patient was under general anesthesia when CV signs were noticed; therefore, the presence or absence of CNS toxicity is uncertain.…”