Sedation

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Sedation

Sedation Levels and Monitoring

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View or edit this diagram in Whimsical.

Sedation Continuum

Level Responsiveness Airway Spontaneous ventilation CVS function
Minimal (Anxiolysis) Normal response to verbal stimulation Unaffected Unaffected Unaffected
Moderate (“Conscious”) Purposeful response to verbal/tactile stimulation No intervention required Adequate Usually maintained
Deep Purposeful response only after repeated/painful stimulation Intervention may be required May be inadequate Usually maintained
General anaesthesia Unarousable Intervention often required Frequently inadequate May be impaired

Sedation exists on a dynamic continuum; clinicians must be able to “rescue” patients who progress to a deeper plane than intended. In the UK, deep sedation is regulated as part of general anaesthesia.

  • Written, procedure-specific consent must include:
  • Description of the planned procedure and sedation technique
  • Benefits and material risks (e.g. hypoxaemia 0.6–1.0 %, unplanned airway intervention 0.1–0.3 %)
  • Alternatives (local anaesthesia alone, regional block, general anaesthesia)
  • Possibility of sedation failure and conversion to GA
  • Post-procedural recovery expectations and discharge criteria

Goals of Procedural Sedation

  1. Respect patient autonomy and comfort
  2. Provide anxiolysis, amnesia and analgesia appropriate to the procedure
  3. Maintain protective airway reflexes and cardiorespiratory stability
  4. Facilitate timely completion of the intervention with rapid recovery and discharge readiness

Contra-Indications

Absolute

  • Inability to maintain/secure airway (e.g. severe OSA with daytime desaturation, craniofacial abnormality)
  • Raised ICP with risk of herniation
  • Glasgow Coma Scale < 14 or evolving neurological deficit
  • Acute decompensated respiratory or cardiac failure
  • Active lower-respiratory tract infection with hypoxaemia
  • Known allergy to proposed sedative/adjuncts
  • Refusal or lack of valid consent

Relative

  • Prematurity (< 60 weeks post-conceptual age)
  • ASA ≥ III (unoptimised) or haemodynamic instability
  • Severe renal or hepatic impairment affecting drug metabolism
  • Full stomach / inadequate fasting when deep sedation is planned
  • Concomitant CNS-depressant therapy (opioids, anticonvulsants, macrolides)
  • Behavioural disorders that preclude cooperation despite minimal sedation

Patient Preparation

  • Fasting (2020 international consensus)
    • Clear fluids: ≥ 2 h
    • Breast milk: ≥ 4 h
    • Light meal / non-human milk: ≥ 6 h
    • Minimal or moderate sedation in low-risk patients may proceed regardless of fasting state if benefits outweigh aspiration risk, provided airway manoeuvres and GA capability are immediately available.

Equipment & Environment—SOAPME

Letter Requirement
S–Suction Two working suction sources; wide-bore Yankauer and paediatric catheters.
O–Oxygen Primary pipeline supply and full E-cylinder (≥ 2000 psi) onsite, with low-pressure alarm.
A–Airway Age-appropriate BVM, oral/nasopharyngeal airways, videolaryngoscope, second-generation supraglottic airway, ETTs with stylets/bougie; cricothyrotomy kit if help is distant.
P–Pharmacy Immediate-use drugs (vasopressors, anticholinergics, sedatives, neuromuscular blockers, reversal agents) stored in tamper-evident tackle box; emergency dantrolene if a volatile agent is available.
M–Monitors Continuous ECG, NIBP, SpO₂, capnography (mandatory for all moderate/deep sedation and GA), inspired O₂, temperature; audible alarms on.
E–Everything else OR-equivalent anaesthesia machine with waste-gas scavenging, defibrillator/ pacing pads, forced-air warmer, radiation shielding (where relevant), compliant electrical outlets, reliable two-way communication with main theatre, adequate lighting.

Monitoring Standards

Sedation depth Clinical Electronic minimum Comments
Minimal (≤ 30 min) Continuous observation of colour, respiratory pattern Intermittent HR, SpO₂, NIBP Suitable for single-agent oral/IN midazolam or N₂O ≤ 50 %
Moderate As above + responsiveness scoring SpO₂, ECG, NIBP every 5 min, capnography† †Capnography reduces hypoxaemia by ~50 % and is recommended whenever an intravenous agent is used
Deep / GA Full anaesthetic monitoring SpO₂, ECG, NIBP, continuous EtCO₂, temperature, neuromuscular function if paralytics used Treat as GA outside theatre; airway equipment and trained anaesthetist mandatory

Documentation

  • Pre-procedure: consent form, anaesthetic assessment, fasting status, airway classification, checklist
  • Intra-procedure: time-stamped record of drugs and doses, vital signs q 5 min, complications and rescue measures
  • Post-procedure: recovery scoring (e.g. Aldrete), discharge instructions including transport and 24-h emergency contact

Staffing Requirements

Technique Sedationist role Assistant Operator
Minimal (single oral/IN agent, ≤ 30 min) Operator-sedationist Competent observer records vitals Same person
Moderate Dedicated sedationist (not involved in procedure) Assistant to help rescue Separate proceduralist
Deep / GA Anaesthetist with GA rescue skills Trained airway assistant Operator

The SASA 2021–26 paediatric guideline mandates that deep sedation be delivered only by doctors credentialed in anaesthesia.

Pharmacology—Key Agents

Drug Adult bolus Onset / duration Advantages Main cautions
Midazolam 1 mg every 1–2 min IV (total ≈ 0.05–0.1 mg kg⁻¹) 2 min / 20–40 min Reliable anxiolysis, amnesia Paradoxical agitation 15 %; resp depression when combined with opioids
Propofol 20–30 mg every 30 s (titrate) 30 s / 5–10 min Rapid recovery; anti-emetic Sudden airway obstruction/apnoea; hypotension; propofol-infusion syndrome with > 48 h high-dose infusions
Ketamine 0.5–1 mg kg⁻¹ IV or 4 mg kg⁻¹ IM 1 min / 10–20 min Preserves airway tone, potent analgesia Hypersalivation, emergence reactions (↓ with midazolam 0.02 mg kg⁻¹)
Dexmedetomidine 0.5–1 µg kg⁻¹ over 10 min then 0.2–0.7 µg kg⁻¹ h⁻¹ 5 min / context-sensitive Rousable, minimal resp depression Bradycardia, hypotension, rebound HTN during loading
Remimazolam 5 mg IV over 1 min; repeat 2.5 mg q 2 min (max 0.2 mg kg⁻¹) 1 min / 10–20 min Ultra-short context-sensitive half-time; reversible with flumazenil Limited post-marketing data; avoid with severe hepatic failure

Flumazenil 0.2 mg (adult) or 20–30 µg kg⁻¹ (child) IV antagonises benzodiazepines; Naloxone 40 µg IV incrementally reverses opioids.

Sedation Outside the Operating Theatre

  • Only ASA I–II patients without difficult-airway predictors
  • “Basic” techniques (single oral/IN agent, N₂O ≤ 50 %) allowed for operator-sedationist model
  • Any combination therapy, N₂O > 50 %, TIVA/TCI, or propofol/ketamine automatically upgrades to advanced sedation requiring full monitoring and a dedicated anaesthetist
  • Discharge criteria: awake, vital signs ± 20 % baseline, able to ambulate (or age-appropriate norm), minimal nausea/pain, responsible adult escort

South African Context–Safe Sedation (SASA 2022 Consolidated)

All procedural sedation must be planned, titrated and monitored as an anaesthetic; the ability to “rescue” a patient who drifts to a deeper plane is mandatory.

Domain Key requirements (SASA 2022)
Patient selection Elective out-of-theatre sedation restricted to ASA I–II adults/children with no anticipated difficult airway. Stable ASA III patients only if a credentialled anaesthetist is present.
Pre-assessment Focused airway exam (Mallampati, neck mobility, mouth opening), fasting status, cardiorespiratory comorbidity, medication review (esp. CNS depressants).
Dosing philosophy Titrate in small, incremental aliquots allowing ≥ 1 min between doses; avoid fixed boluses. Document total dose and effect.
Environment & equipment SOAPME checks; full anaesthetic monitoring for any IV, multi-drug or deep sedation (SpO₂, ECG, NIBP q 5 min, continuous EtCO₂).
Personnel Operator-sedationist permitted only for single-agent minimal sedation ≤ 30 min. All other techniques require a dedicated sedationist with airway skills.
Recovery & discharge Aldrete ≥ 9, stable vitals for 30 min, able to ambulate (or age-appropriate norm), responsible adult escort, written post-sedation instructions.

ICU Sedation & Analgesia

2025 SCCM Focused PADIS Update–Headline Changes

  1. Target light sedation (RASS −2 to 0) in all mechanically ventilated adults unless specific indications for deep sedation exist.
  2. Analgesia-first strategy: fentanyl or remifentanil infusions before initiating sedatives.
  3. Preferred sedatives
    • Propofol or dexmedetomidine over benzodiazepines in all patient groups, including post-cardiac surgery.
    • Remimazolam may be considered when haemodynamic stability is critical, but evidence remains limited.
  4. Sedation optimisation: daily SAT + SBT (paired), nurse-driven protocols, and objective sedation scoring every 2–4 h
  5. Adjunct monitoring: processed EEG (BIS 40–60) when deep sedation or neuromuscular blockade is required.

Richmond Agitation–Sedation Scale (RASS)

Score Response Clinical action
+4 to +1 Combative → Restless Treat pain/anxiety, consider haloperidol/dexmedetomidine, provide reassurance
0 Alert & calm Maintain
−1 to −2 Drowsy → Light sedation Acceptable target for most ICU patients
−3 Moderate sedation Review indication; attempt SAT
−4/−5 Deep sedation / Unrousable Ensure indication (e.g. ARDS proning); initiate EEG or BIS

Proceed to delirium screening (CAM-ICU) if RASS ≥ −2.

ICU Liberation ABCDEF Bundle–2024 Evidence

  • A Assess, prevent & manage pain
  • B Both SAT & SBT daily
  • C Choice of analgesia/sedation (avoid benzodiazepines, prefer propofol/dex)
  • D Delirium assessment (CAM-ICU q 12 h); non-pharmacological first-line
  • E Early mobilisation within 48 h of stability
  • F Family engagement at bedside or virtually

Multicentre data in > 6 000 ventilated adults show full bundle compliance reduces 28-day mortality by 25 % and delirium days by 50 %.

Emerging Sedation Agents

Drug ICU / Procedural role Key advantages Key cautions Recent evidence
Remimazolam Procedural sedation; explored for ICU infusion Ultra-short context-sensitive half-time, haemodynamic stability, reversible with flumazenil Slightly longer awakening vs propofol; respiratory depression similar to midazolam 2025 meta-analysis (11 RCTs, n = 5 642)–↓ hypoxaemia, ↓ hypotension vs propofol
Fospropofol disodium Endoscopy & elderly day-case sedation Water-soluble (no lipid emulsion), minimal injection pain Delayed onset (4-8 min); paraesthesia; formaldehyde metabolite 2024 RCT in elderly endoscopy–non-inferior efficacy, ↓ hypotension vs propofol
Methoxyflurane (Penthrox®) Self-administered inhalational analgesia for short procedures Rapid onset, minimal respiratory depression, short recovery Nephrotoxic metabolites–avoid eGFR < 60 mL min⁻¹ 1.73 m⁻²; occupational exposure; limited paediatric data 2023 systematic review–effective adjunct or alternative to IV midazolam/opioid sedation, faster discharge times

Practical Pearls

  • Remimazolam dosing (adult): 6 mg IV over 1 min; 2.5 mg repeats q 2 min (max ≈ 0.2 mg kg⁻¹).
  • Fospropofol dosing: 6.5 mg kg⁻¹ IV over 60 s; supplemental 1.6 mg kg⁻¹ q 4 min.
  • Methoxyflurane: 3 mL inhaler provides ≈ 25 min analgesia; patient controls concentration via finger on dilutor port. Provide supplemental O₂ if SpO₂ < 94 %.

Links


Past Exam Questions

Sedation for Biventricular Pacing-Defibrillator Insertion

List your main concerns when assessing a patient’s suitability for sedation for this procedure. (10)

Safe Practice for Operator-Sedationist

A plastic surgical colleague wants to sedate patients in his procedure room for minor cosmetic procedures. He asks for advice, as he plans to sedate patients himself without an anaesthetist present.

What information (based on SASA procedural sedation guidelines) would you provide as a guideline for safe practice? (10)


References:

  1. Khorsand, S., Karamchandani, K., & Joshi, G. P. (2022). Sedation-analgesia techniques for nonoperating room anesthesia: an update. Current Opinion in Anaesthesiology, 35(4), 450-456. https://doi.org/10.1097/aco.0000000000001123
  2. American Society of Anesthesiologists Task Force on Moderate Procedural Sedation and Analgesia. Practice Guidelines for Moderate Procedural Sedation and Analgesia 2018. Anesthesiology 2018;128:437-479. https://pubmed.ncbi.nlm.nih.gov/29334501 PubMed
  3. Academy of Medical Royal Colleges. Safe Sedation Practice for Healthcare Procedures–Update 2021. London: AoMRC, 2021. https://www.aomrc.org.uk AOMRC
  4. South African Society of Anaesthesiologists. Paediatric Guidelines for Procedural Sedation and Analgesia 2021–2026. SAJAA 2021;27(Suppl 2):S1-83. painsa.org.za
  5. An international multidisciplinary consensus statement on fasting before procedural sedation in adults and children. Anaesthesia 2020;75:374-385. Anaesthetists Publications
  6. McCracken GC, Smith AF. Breaking the fast for procedural sedation: changing risk or risking change? Anaesthesia 2020;75:1010-1013. PubMed
  7. Royal College of Emergency Medicine. Best Practice Guideline: Procedural Sedation in the Emergency Department. RCEM 2022. ABEM
  8. Jhuang BJ et al. Efficacy and safety of remimazolam for procedural sedation: meta-analysis of RCTs. Front Med 2021;8:641866. PubMed
  9. South African Society of Anaesthesiologists. Guidelines for the Safe Use of Procedural Sedation and Analgesia (2nd ed.). SAJAA 2016. sajaa.co.za
  10. South African Society of Anaesthesiologists. Anaesthesia Practice Guidelines–Consolidated 2022. Johannesburg: SASA; 2022. sasaweb.com
  11. Lewis K, Balas MC, Stollings JL, et al. A focused update to the PADIS guideline. Crit Care Med 2025;53:e711-e727. Society of Critical Care Medicine (SCCM)
  12. Kerson AG, Deem S, Cooke CR. Validation of the Richmond Agitation–Sedation Scale across ICU populations. Am J Respir Crit Care Med 2023;208:1125-1134. ATS Journals
  13. Girard TD, Pun BT, Barnes-Daly MA, et al. Implementing the ABCDEF bundle improves survival and brain function. Crit Care Explor 2024;6:e0945. Lippincott Journals
  14. Zhong J, Liu B, Wang Y, et al. Remimazolam vs propofol for procedural sedation: systematic review and meta-analysis. Anesth Analg 2025;140:256-268. PubMed
  15. Zhang H, Chen Q, Li R, et al. Remimazolam for high-risk GI endoscopy: randomised trial. Lancet Reg Health West Pac 2023;33:100689. PubMed
  16. Liu X, Deng T, Huang G, et al. Fospropofol vs propofol for elderly bidirectional endoscopy: RCT. Front Pharmacol 2024;15:1378081. [Frontiers](https://www.frontiersin.org/journals/pharmacology/articles/10.3389/fphar.2024.1378081/full?utm_source=chatgpt.com
  17. Reeve R, Rades T, Wood MJ. Inhaled methoxyflurane for procedural analgesia: systematic review. Pain Pract 2023;23:456-470. PMC
  18. de Klerk R, Jonas K. Methoxyflurane vs fentanyl–midazolam for office hysteroscopy: protocol. ClinTrials.gov NCT06899724 (accessed 25 Jul 2025). ClinicalTrials.gov
  19. Developing capnography standards for procedural sedation. Front Med 2022;9:867536. Frontiers
  20. BJA Education. Developments in procedural sedation for adults. BJA Educ 2022;22:190-196. BJAED
  21. Kodali BS. Capnography outside the operating room. Anesthesiology 2013;118:192-201 (still current for technical standards)
  22. SASA. (2020). SASA Guidelines for the safe use of procedural sedation and analgesia for diagnostic and therapeutic procedures in adults: 2020–2025. The South African Society of Anaesthesiologists. Retrieved from SASA website.
  23. Sneyd, J. R. (2022). Developments in procedural sedation for adults. BJA Education, 22(7), 258-264. https://doi.org/10.1016/j.bjae.2022.02.006

Summaries:
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