Anaes · Anaesthetic adjuncts
Anaesthetic adjuncts
Also known as Anaesthetic adjuncts · Dexmedetomidine · Ketamine · Lidocaine infusion · Magnesium · Clonidine · Gabapentinoid · Benzodiazepine
The anaesthetic adjuncts are the agents used alongside the primary anaesthetic to enhance the anaesthesia, the analgesia, the sedation, and the side-effect reduction. The framework rests on the alpha-2 agonists (the dexmedetomidine, the clonidine), the NMDA antagonists (the ketamine, the magnesium), the sodium-channel blockade (the lidocaine infusion), the benzodiazepines (the midazolam), the gabapentinoids, the beta-blockers, and the intrathecal and the regional adjuvants. The multimodal opioid-sparing and the OFA the modern strategy.
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Red flags
- Dexmedetomidine and clonidine cause bradycardia and hypotension — reduce or stop the infusion before stacking vasopressors blindly.
- Intravenous lidocaine infusions carry LAST risk — account for total amide dose from all regional and systemic sources.
- Magnesium potentiates neuromuscular blockade — confirm TOF recovery before extubation.
- Neuraxial morphine causes delayed respiratory depression (peak 6–24 h) — overnight monitoring is mandatory.
- Gabapentinoids sedate and can depress respiration with opioids, especially in the elderly and renally impaired.
Meet the patient
A 45-year-old man on long-term oxycodone for chronic back pain presents for an open bowel resection. His daily opioid dose is high, his pain threshold is blunted, and a standard morphine PCA will not be enough. You need a multimodal plan that attacks pain from every mechanism — not a bigger syringe of opioid.[1]
Examiners test whether you can design that plan with doses, mechanisms, who should not receive each drug, and how toxicities interact. A plan without numbers or stop rules is polypharmacy, not analgesia.[1][2][3][4]
References4ShowHide
- [1]Al Subhi M, et al. Effect of Perioperative Ketamine and Esketamine on Postoperative Fatigue: A Systematic Review and Meta-Analysis of Randomized Controlled Trials Medicina (Kaunas), 2026.PMID 42356168
- [2]Muntean C, et al. Intravenous Lidocaine as an Adjunct for Postoperative Recovery After Open Abdominal Surgery: A Systematic Review J Clin Med, 2026.PMID 42278931
- [3]Tarimah K, et al. Magnesium Sulfate as a Multimodal Anesthetic Adjuvant in Brain Tumor Surgery: A Systematic Review and Meta-Analysis of Hemodynamic, Analgesic, and Biomarker Outcomes J Clin Med, 2026.PMID 42355804
- [4]Ollosu M, et al. Efficacy and safety of intrathecal adjuvants in lower limb orthopaedic surgery: a systematic review and network meta-analysis of randomised controlled trials J Anesth Analg Crit Care, 2026.PMID 42321879