Anaes · TIVA & target-controlled infusion
Effect-site targeting in clinical TIVA practice
Also known as Effect-site targeting · Effect-site TCI · ke0 and the effect compartment · Propofol-remifentanil TIVA · Clinical TIVA titration · Closed-loop anaesthesia
Effect-site targeting is the clinical refinement of target-controlled infusion that aims the pump at the brain rather than the plasma. By modelling the plasma-to-effect-site delay (ke0), it allows rapid, smooth induction and precise titration to a processed-EEG depth monitor — the practical basis of modern propofol-remifentanil TIVA, of shared-airway anaesthesia, and of emerging closed-loop systems.
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Target exams
Red flags
- Effect-site targeting accepts a transient plasma overshoot; in the elderly or haemodynamically fragile this overshoot can cause hypotension — start with a low target and titrate.
- Synergistic remifentanil markedly deepens respiratory depression; a high remifentanil target with a sedative infusion risks apnoea and chest-wall rigidity — titrate to the stimulus and monitor ventilation.
- The processed-EEG trace can be misleading: paradoxical excitation, electrocautery artefact and neuromuscular activity all distort the index — interpret it with clinical signs, never in isolation.
- TIVA in the unsecured or shared airway can mask lightening anaesthesia; a fall in surgical conditions or movement may be the first sign the target is too low.
- Closing the loop on the wrong signal: closed-loop systems only perform well when the depth signal is reliable; artefact drives the pump to overdose or underdose.
- Recovery from a long effect-site infusion tracks the context-sensitive half-time; a high target sustained to the end of a long case delays emergence.
Meet the patient
A 55-year-old man presents for robotic-assisted bronchoscopy under general anaesthesia. The bronchoscopist will occupy the airway throughout, so there is no endotracheal tube and no volatile circuit — you maintain anaesthesia with a propofol-remifentanil effect-site TIVA while the surgeon works through an open, shared airway. Every adjustment you make is a predicted brain concentration on a screen, and your only confirmation that the prediction matches reality is the processed-EEG trace and the patient's clinical signs.[2]
The two questions every effect-site TIVA stem turns on: is the predicted brain concentration producing the intended depth? (processed EEG, clinical signs) and is the target too high for this patient's haemodynamics? (the overshoot that drives the brain to target also depresses the blood pressure).[4]
References6ShowHide
- [1]He ZY, et al. Comparison of propofol-remifentanil target-controlled infusion with lidocaine versus neuromuscular blockade for laryngoscopy Minerva Anestesiol, 2026.PMID 42267885
- [2]Stretch B, et al. Peri-operative care of patients undergoing robotic-assisted bronchoscopy under general anaesthesia - a single-centre retrospective cohort study Anaesth Rep, 2026.PMID 42283065
- [3]Felippe VA, et al. Closed-loop systems for automated hypnotic drug delivery during general anaesthesia: a systematic review and meta-analysis Br J Anaesth, 2026.PMID 42014224
- [4]Stojanovic M, et al. What's new in intravenous anaesthesia? Curr Opin Anaesthesiol, 2026.PMID 41677226
- [5]Newman D, et al. Reframing paradoxical excitation: disentangling electroencephalogram complexity and entropy reveals resting-state dynamics associated with propofol susceptibility in healthy adults Br J Anaesth, 2026.PMID 42225443
- [6]Kim HY, et al. Respiratory Depression Following Concomitant Infusion of Remimazolam and Remifentanil Using Targeted Effect-Site Concentrations: A Randomized Controlled Trial Medicina (Kaunas), 2026.PMID 42195193