Local anaesthetics (LA) block pain signals for the patient ahead of surgery, with lidocaine, lignocaine, articaine and mepivacaine among the most prevalent.[i] However, a landmark 2025 study confirmed that lidocaine is now the leading reported cause of local anaesthetic-related death worldwide.[ii]
This is concerning, reminding dental professionals of the high risk of anaesthetics and that dental deaths are still under-reported in the data. It is essential that continuing research is shared, enabling clinicians to understand the risks and better mitigate them for improved patient care and predictable surgical outcomes.
LAST but not least
Local anaesthetic systemic toxicity (LAST) occurs when the concentration of a local anaesthetic in the bloodstream is too high, exceeding the toxic threshold. Whilst rare, the impact is fast: the brain is affected and seizures, cardiovascular collapse and death are likely to happen within minutes.[iii]
LAST is not exclusive to hospitals. In dental surgeries, treatments such as routine inferior alveolar nerve blocks and implants may be the scene of LAST occurrence. Further, if the clinician does not know the safe dose or recognise the warning signs, they will be less prepared to manage it and the consequences may be grievous.
Is LAST awareness low?
The 2025 report analysed 55 years of LA reports, dating from 1968 to 2023. Out of 22,050 LA adverse events, there were 1,473 reported deaths. Notably, even after 2010 practice advisories and unlike other anaesthetic alternatives, deaths relating to lidocaine did not fall, establishing it as the leading cause of death among LAs.
Knowing the dose is essential to reduce the risk of LAST. This is itself a challenge – how many dental clinicians know the maximum recommended dose of lignocaine for a 70kg adult? The answer is complicated; answering 300mg or 4.4mg/kg means quoting the product insert. 500mg or 7mg/kg means quoting the British National Formulary (BNF) and the Food and Drug Administration (FDA). Both answers are used in UK dental practice, with a difference of one cartridge for a 70kg adult – but some clinicians may be unaware of the discrepancy at all. It is vital that dental professionals know which reference to apply and why, and it should always be documented. This is particularly important for dental implantologists.
The implant problem
Full-arch or full-mouth implant surgery is an impressive, technically challenging treatment for restoring a patient’s smile, but it can take between 4 and 8 hours. The sustained length of time introduces a dosing risk that a 1-hour extraction surgery avoids. Prolonged surgeries demand the initial administration of LA, a top-up when its effect lessens, re-administration for different anatomical regions, and potentially a supplement to support wound closure for postoperative analgesia. Collectively, the dosage of LA is high and this intensifies the risk of LAST. Ahead of a full-arch implant surgery, clinicians should:
- Calculate the fractional dose budget before the case (not during it)
- Allocate doses by anatomical region: upper right, upper left, lower right, lower left, palate
- Assign a named team member to track the running total after every top-up
- Use articaine as the primary intraoperative agent to maximise clearance between doses
- Have intravenous lipid emulsion (ILE) on site
- Ensure a specialist anaesthetist or sedationist is present for compliance
Managing LAST
Even when taking the necessary steps to control doses and decrease the health risk, clinicians must be able to recognise and manage LAST as it may not be immediately obvious, with 40 per cent of cases presenting atypically.[iv] The traditional teaching sequence begins with a metallic taste, then tinnitus, agitation, seizure and cardiovascular collapse. However, LAST may not always follow that order. Some of the earlier signs in the sequence, such as dizziness and agitation, can also be attributed to patient anxiety or an adrenaline reaction, which is why close attention to the symptoms is needed.
The management of LAST is sequential and prioritised. Firstly, the injection of LA must be immediately stopped. Emergency services must be contacted and the staff alerted. As general dental practices are unlikely to have ILE, a non-rebreather mask, midazolam for seizures or adrenaline, the priority is to secure the airway whilst awaiting the paramedics and transfer to hospital. For compliant specialist practices, ILE must be stocked on site, however.
Confident in your referrals
Delivering prolonged dental implant treatments comes with a high risk. For complex cases, refer patients to the Ucer Clinic in Salford. Led by Professor Cemal Ucer, an internationally recognised Specialist Oral Surgeon, the talented team deliver outstanding implant treatments with a strong focus on patient care and life-changing treatments.
Local anaesthetics are necessary, but that doesn’t mean they are always safe. By understanding the risks of LAST and how the team can manage it, dental practices can feel more confident in their workflow.
Author: Professor Cemal Ucer, Specialist Oral Surgeon
Please contact Professor Ucer at ucer@icedental.institute or Mel Hay at mel@mdic.co
01612 371842
[i] Akhtar, N., Brizuela, M. and Stenhouse, P. D (2025). Local Anesthetic Drugs Used In Dentistry. [online] Nih.gov. StatPearls Publishing. Available at: https://www.ncbi.nlm.nih.gov/books/NBK610935/ [Accessed 29 July 2026].
[ii] Anon, (2022). [online] Bmj.com. Available at: https://rapm.bmj.com/content/early/2025/07/14/rapm-2025-106464 [Accessed 29 July 2026].
[iii] Mahajan, A. and Derian, A. (2022). Local Anesthetic Toxicity. [online] PubMed. Treasure Island (FL): StatPearls Publishing. Available at: https://www.ncbi.nlm.nih.gov/books/NBK499964/ [Accessed 29 July 2026].
[iv] Neal, J.M., Barrington, M.J., Fettiplace, M.R., Gitman, M., Memtsoudis, S.G., Mörwald, E.E., Rubin, D.S. and Weinberg, G. (2018). The Third American Society of Regional Anesthesia and Pain Medicine Practice Advisory on Local Anesthetic Systemic Toxicity. Regional Anesthesia and Pain Medicine, 43(2), pp.113–123. doi:10.1097/aap.0000000000000720.
