What are the key concepts and techniques in clinical anesthesia that should be included in a comprehensive cheat sheet for quick reference?

Clinical Anesthesia Quick Reference Guide

Preoperative Assessment and Preparation

Airway Evaluation

Conduct a focused airway assessment examining specific anatomical features that predict difficult intubation and ventilation. 1

• History factors to identify:

  • Previous anesthesia complications or difficult intubation 1
  • Stridor, snoring, or obstructive sleep apnea 1
  • Advanced rheumatoid arthritis 1
  • Chromosomal abnormalities (e.g., trisomy 21) 1

• Physical examination predictors:

  • Mouth opening capacity and Mallampati classification 1
  • Thyromental distance and neck mobility 1
  • Presence of facial hair, obesity, or anatomical abnormalities 1

Fasting Guidelines

Apply standardized NPO times based on ingested material type to minimize aspiration risk. 1

• Clear liquids: 2 hours 1
• Breast milk: 4 hours 1
• Non-human milk/light meals: 6 hours 1
• Fatty foods or meat: 8+ hours 1

Equipment Preparation

Perform a systematic equipment check before every case, with weekly oxygen failure alarm testing. 1

• Daily checks include:
  • Pipeline gas connections with "tug test" (avoid excessive force) 1
  • Oxygen reserve cylinder availability 1
  • Flowmeter operation and anti-hypoxia device function 1
  • Emergency oxygen bypass control 1
  • Suction apparatus with rapid negative pressure development 1
  • Breathing system "two-bag test" for leaks 1
  • Vaporizer filling and locking mechanism 1

Medications for Airway Management

Induction Agents

Propofol: Titrate slowly in cardiac and high-risk patients to minimize hemodynamic depression. 2

• Standard dosing:

  • Healthy adults: 1-2.5 mg/kg IV for induction 2
  • Cardiac patients: 0.5-1.5 mg/kg at 20 mg every 10 seconds 2
  • Elderly/ASA III-IV: Avoid rapid bolus, use slow titration 2

• Maintenance:

  • General surgery: 100-200 mcg/kg/min infusion 2
  • Cardiac cases: ≥100 mcg/kg/min as primary agent 2
  • Pediatric: 200-300 mcg/kg/min initially, then 125-150 mcg/kg/min 2

Sevoflurane: Monitor for arrhythmias with epinephrine and hypotension with calcium antagonists. 3

• Reduces MAC by ~50% when combined with 50% N₂O in adults 3
• Potentiates neuromuscular blockade—reduce muscle relaxant doses during maintenance 3
• Avoid use with desiccated CO₂ absorbents containing potassium hydroxide 3

Neuromuscular Blockade

Administer neuromuscular blockers before intubation when spontaneous breathing is not required to optimize conditions. 4

• Do not reduce doses for endotracheal intubation 3
• During maintenance, reduce doses compared to N₂O/opioid technique 3
• Guide supplemental dosing with nerve stimulation monitoring 3

Sedation for Procedural Anesthesia

Use dexmedetomidine as first-line sedative, with or without supplemental agents, for awake procedures. 5

• Provides anxiolysis while maintaining respiratory drive 5
• Can be combined with midazolam, ketamine, or opioids 5
• Ketamine combined with sedatives acceptable for moderate sedation 1

Airway Management Techniques

Pre-oxygenation and Oxygenation Strategies

Apply apnoeic oxygenation during intubation in neonates and consider high-flow nasal oxygen in adults. 4, 1

• Standard pre-oxygenation targets end-tidal O₂ approaching 100% 1
• High-flow nasal oxygen (HFNO) extends safe apnea time 1
• Supplemental oxygen via nasal cannula or specialized devices during sedation 1

Videolaryngoscopy

Use videolaryngoscope with age-adapted standard blade as first-choice device for tracheal intubation. 4, 1

• Provides superior glottic visualization compared to direct laryngoscopy 1
• Use stylet to reinforce tubes with hyperangulated blades 4
• Position for anticipated difficult intubation without difficult mask ventilation 1

Difficult Airway Algorithms

For anticipated difficult intubation WITH difficult mask ventilation: Maintain spontaneous ventilation and consider awake intubation. 1

• Perform nerve blocks for superior airway anesthesia 5
• Ultrasound guidance reduces local anesthetic volume and improves block density 5
• Topicalization alternatives if nerve blocks unavailable 5

For unanticipated difficult intubation: Limit attempts to three maximum. 1, 4

• First attempt by most experienced provider 1
• Optimize conditions between attempts 1
• Use supraglottic airway for rescue oxygenation if intubation fails 4
• Proceed to surgical cricothyroidotomy if cannot intubate/cannot oxygenate 1

Intubation in Special Circumstances

Pre-hospital/trauma: Remove front of hard collar after establishing manual in-line stabilization. 1

• Apply cricoid pressure during induction (low threshold to remove if impairs view) 1
• Use intubating bougie routinely 1
• Confirm placement with clinical assessment AND waveform capnography 1
• Secure tube with adhesive tape rather than circumferential tie in head injury 1

Pediatric airway (neonates/infants): Ensure adequate sedation depth and consider neuromuscular blockade. 4

• Administer neuromuscular blocker when spontaneous breathing unnecessary 4
• Use videolaryngoscope with standard blade 4
• Apply apnoeic oxygenation 4
• Minimize pain on propofol injection via large veins or lidocaine pretreatment 2

Monitoring During Anesthesia

Essential Monitoring Parameters

Implement continuous capnography, pulse oximetry, blood pressure, heart rate, and ECG for all cases. 1

• Level of consciousness: Responsiveness assessment 1

• Ventilation monitoring:

  • Continual end-tidal CO₂ monitoring (capnography) 1
  • Observation of chest excursion and auscultation 1
  • Plethysmography as adjunct 1

• Oxygenation: Continuous pulse oximetry 1

• Hemodynamics: Blood pressure, heart rate, ECG 1

• Documentation: Contemporaneous recording of all parameters 1

Dedicated Monitoring Personnel

Assign an individual exclusively for patient monitoring during moderate sedation. 1

• Separate from person performing procedure 1
• Capable of establishing patent airway and positive pressure ventilation 1
• Advanced life support skills required 1

Extubation Management

Extubation Criteria

Verify all five essential criteria before extubation: spontaneous breathing, TOF >90%, hemodynamic stability, awake/responsive, and no surgical risk. 6

• Respiratory parameters:

  • Regular spontaneous breathing pattern 6
  • Respiratory rate 10-25 breaths/minute 6
  • Adequate tidal volume (5-8 ml/kg) 6
  • Satisfactory capnogram 6
  • Maintained oxygen saturation 6

• Neuromuscular function:

  • Quantitative Train-of-Four >90% 6

• Neurological status:

  • Awake and responds to commands 6

• Hemodynamics:

  • Stable and satisfactory parameters 6

High-Risk Extubation

Identify risk factors and implement advanced techniques for patients at elevated extubation failure risk. 6

• Risk factors include:

  • Residual paralysis 6
  • Airway obstruction 6
  • Heart failure or COPD 6
  • Malnutrition 6
  • Previous difficult intubation 6

• Advanced techniques:

  • Bailey maneuver (laryngeal mask exchange) for cardiovascular stimulation concerns 6
  • Prophylactic high-flow nasal oxygen post-extubation 6
  • Prophylactic non-invasive ventilation for high-risk COPD patients 6
  • Continuous monitoring of vital signs and oxygen saturation 6

Emergency Management

Anaphylaxis Recognition and Treatment

Administer adrenaline 50 mcg IV immediately for suspected anaphylaxis—do not delay for diagnostic certainty. 1

• Clinical features:

  • Cardiovascular collapse (most common in allergic anaphylaxis) 1
  • Bronchospasm (more common with pre-existing asthma) 1
  • Cutaneous signs (flushing/urticaria in majority, but absence doesn't exclude) 1
  • Onset typically within minutes, may delay up to one hour 1

• Immediate management sequence:

  1. ABC approach with team activation 1
  2. Remove all potential causative agents (IV colloids, latex, chlorhexidine) 1
  3. Maintain airway, administer 100% oxygen, intubate if necessary 1
  4. Elevate legs if hypotensive 1
  5. Adrenaline 50 mcg IV (0.5 ml of 1:10,000), repeat as needed 1
  6. Consider adrenaline infusion if multiple doses required 1
  7. Rapid IV fluid resuscitation with saline 0.9% or lactated Ringer's 1

• Secondary management:

  • Chlorphenamine 10 mg IV 1
  • Hydrocortisone 200 mg IV 1
  • Alternative vasopressor (e.g., metaraminol) if adrenaline insufficient 1
  • Salbutamol infusion for persistent bronchospasm 1
  • Mast cell tryptase samples: immediate, 1-2 hours, and 24 hours post-event 1

Emergency Medications and Equipment

Maintain immediately accessible emergency drugs and airway equipment at every anesthesia location. 1

• Essential medications:

  • Epinephrine, ephedrine, vasopressin 1
  • Atropine 1
  • Nitroglycerin (tablets/spray) 1
  • Amiodarone, lidocaine 1
  • Glucose (IV/oral) 1
  • Diphenhydramine 1
  • Corticosteroids (hydrocortisone, methylprednisolone, dexamethasone) 1
  • Benzodiazepines, beta-blockers, adenosine 1

• Airway devices:

  • Supraglottic airways (e.g., laryngeal mask) 1
  • Equipment for surgical cricothyroidotomy 1
  • Positive pressure ventilation capability 1

Ergonomics and Safety

Positioning and Workspace Organization

Maintain the "triangle" configuration with machine, patient, and anesthesiologist each within 45° of sagittal plane. 1

• Optimal posture:
  • Back straight or slightly reclined (95-110°) 1
  • Shoulders abducted <20° 1
  • Elbows flexed 90-100° 1
  • Wrist extension/deviation <15° 1
  • Feet flat with thighs parallel to floor 1

Patient Transfer

Use mechanical transfer devices for all patient moves to prevent musculoskeletal injury. 1

• Friction-reducing sheets with slider boards 1
• Air-assisted devices for heavier patients 1
• Verify device safe working load not exceeded 1

Regional Anesthesia Ergonomics

Position equipment and patient to perform neuraxial blocks without excessive thoracolumbar flexion or leaning. 1

• Maintain asepsis without compromising operator posture 1
• Ultrasound screen at eye level for peripheral nerve blocks 1
• Adequate lighting and workspace organization 1

Quality Improvement and Documentation

Process Implementation

Establish and implement quality improvement processes with contemporaneous parameter recording. 1

• Document all monitored parameters in real-time 1
• Track adverse events and near-misses 1
• Regular equipment maintenance and testing schedules 1
• Weekly oxygen failure alarm verification with written records 1

Drug Interactions and Precautions

Monitor ECG when administering epinephrine with sevoflurane due to arrhythmia risk. 3

• Marked hypotension possible with calcium antagonists and sevoflurane 3
• MAO inhibitors increase hemodynamic instability risk with inhalational agents 3
• Propofol increases CNS depression with other sedatives, anesthetics, opioids 2