Current evidence is not in support of lipid rescue therapy in local anaesthetic systemic toxicity

Nanotherapeutics for Alleviating Anesthesia-Associated Complications

Current management of anesthesia-associated complications falls short in terms of both efficacy and safety. Nanomaterials with versatile properties and unique nano-bio interactions hold substantial promise as therapeutics for addressing these complications. This review conducts a thorough examination of the existing nanotherapeutics and highlights the strategies for developing prospective nanomedicines to mitigate anesthetics-related toxicity. Initially, general, regional, and local anesthesia along with the commonly used anesthetics and related prevalent side effects are introduced. Furthermore, employing nanotechnology to prevent and alleviate the complications of anesthetics is systematically demonstrated from three aspects, that is, developing 1) safe nano-formulization for anesthetics; 2) nano-antidotes to sequester overdosed anesthetics and alter their pharmacokinetics; 3) nanomedicines with pharmacodynamic activities to treat anesthetics toxicity. Finally, the prospects and challenges facing the clinical translation of nanotherapeutics for anesthesia-related complications are discussed. This work provides a comprehensive roadmap for developing effective nanotherapeutics to prevent and mitigate anesthesia-associated toxicity, which can potentially revolutionize the management of anesthesia complications.

Sodium bicarbonate reverts electrophysiologic cardiotoxicity of ropivacaine faster than lipid emulsions in a porcine model

Ropivacaine has been described as a safer local anaesthetic (LA); however, serious cardiotoxic accidents have been reported. Intravenous-lipid-emulsion (ILE) therapy during LA intoxication seems to act as an antidote. Sodium bicarbonate is the standard treatment for sodium channel blocker drug toxicity. We compared both antidotes on the reversion of electrophysiologic toxicity induced by ropivacaine. Ropivacaine 5 mg kg^-1 was administered in 24 pigs, and 3 min later, the animals received ILE: 1.5 ml kg^-1  + 0.25 ml kg^-1  min^-1 (ILE group); sodium bicarbonate: 2 mEq kg^-1  + 1 mEq kg^-1  h^-1 (NaHCO₃ group); saline solution (CTL group). Electrophysiological parameters were evaluated for 30 min. The area under the curve (AUC) for the first 5 or 30 min was compared between groups. Ropivacaine induced a lengthening of the PR interval by 17% (P = 0.0001), His-ventricle-interval by 58% (P = 0.001), sinus QRS complex by 56% (P = 0.0001), paced QRS at 150 bpm by 257% (P = 0.0001), and at 120 bpm by 143% (P = 0.0001) in all groups. At 5 min after treatment, sinus QRS in the NaHCO₃ group was shorter than that in the CTL group (AUC_QRS5 , P = 0.003) or ILE group (AUC_QRS5 , P = 0.045). During the first minute, seven of the animals in the NaHCO₃ group vs. two in the ILE or 0 in the CTL group recovered more than 30% of the sinus QRS previously lengthened by ropivacaine (P = 0.003). Sodium bicarbonate reversed the electrophysiological toxicity of ropivacaine faster than ILE and control groups.

Lipid emulsions in the treatment of intoxications by local anesthesics and other drugs. Review of mechanisms of action and recommendations for use

Intravenous lipid emulsions (ILEs) have been used widely for the treatment of local anesthetic (LA) poisoning and have been proposed as a treatment for intoxication by other drugs. However, the degree of evidence for this kind of therapy is not strong, as it comes mostly from clinical cases. The aim of this narrative review is to describe the proposed mechanisms of action for ILEs in poisoning by LA and other drugs and to evaluate recent studies in animals that support the recommendations for their use and the experience in humans that support the use of ILESs in both LA and other drug poisoning. For this purpose, a search was performed in the Embase, Medline and Google Scholar databases covering relevant articles over the last 10 years. In the case of AL poisoning, we recommend applying the protocols dictated by international guidelines, knowing that the degree of evidence is not very high. In poisoning by other drugs, ILEs are recommended in serious situations induced by liposoluble xenobiotics that do not respond to standard treatment.

Lipid emulsions in the treatment of intoxications by local anesthesics and other drugs. Review of mechanisms of action and recommendations for use

Intravenous lipid emulsions (ILEs) have been used widely for the treatment of local anesthetic (LA) poisoning and have been proposed as a treatment for intoxication by other drugs. However, the degree of evidence for this kind of therapy is not strong, as it comes mostly from clinical cases. The aim of this narrative review is to describe the proposed mechanisms of action for ILEs in poisoning by LA and other drugs and to evaluate recent studies in animals that support the recommendations for their use and the experience in humans that support the use of ILESs in both LA and other drug poisoning. For this purpose, a search was performed in the Embase, Medline and Google Scholar databases covering relevant articles over the last 10 years. In the case of AL poisoning, we recommend applying the protocols dictated by international guidelines, knowing that the degree of evidence is not very high. In poisoning by other drugs, ILEs are recommended in serious situations induced by liposoluble xenobiotics that do not respond to standard treatment.

Lipid emulsion in local anesthetic toxicity

PURPOSE OF REVIEW

Enthusiasm for regional anesthesia has been driven by multimodal benefits to patient outcomes. Despite widespread awareness and improved techniques (including the increasing use of ultrasound guidance for block placement), intravascular sequestration and the attendant risk of local anesthetic systemic toxicity (LAST) remains. Intravenous lipid emulsion (ILE) for the treatment of LAST has been endorsed by anesthetic regulatory societies on the basis of animal study and human case report data. The accumulated mass of reporting now permits objective interrogation of published literature.

RECENT FINDINGS

Although incompletely elucidated the mechanism of action for ILE in LAST seemingly involves beneficial effects on initial drug distribution (i.e., pharmacokinetic effects) and positive cardiotonic and vasoactive effects (i.e., pharmacokinetic effects) acting in concert. Recent systematic review by collaborating international toxicologic societies have provided reserved endorsement for ILE in bupivacaine-induced toxicity, weak support for ILE use in toxicity from other local anesthetics, and largely neutral recommendation for all other drug poisonings. Work since publication of these recommendations has concluded that there is a positive effect on survival for ILE when animal models of LAST are meta-analyzed and evidence of a positive pharmacokinetic effect for lipid in human models of LAST.

SUMMARY

Lipid emulsion remains first-line therapy (in conjunction with standard resuscitative measures) in LAST. Increasing conjecture as to the clinical efficacy of ILE in LAST, however, calls for high-quality human data to refine clinical recommendations.