What are the key considerations for administering general anesthesia?

Key Considerations for Administering General Anesthesia

General anesthesia requires continuous presence of an anesthetist throughout the procedure, with mandatory monitoring of ECG, SpO₂, non-invasive blood pressure, and capnography from before induction through recovery, and capnography must continue until any artificial airway is removed and verbal response is re-established. 1

Pre-Anesthetic Evaluation

Essential Patient History Components

• Age, weight (in kg), and gestational age at birth (preterm infants may have apnea sequelae) 1
• Allergy history: food, medication allergies, and previous adverse drug reactions 1
• Medication review: prescription, over-the-counter, herbal, and illicit drugs with dosages, timing, and routes 1
  • Herbal medicines (St John's wort, ginkgo, ginger, ginseng, garlic) may inhibit cytochrome P450, prolonging drug effects and altering blood concentrations of midazolam and other agents 1
  • Kava may potentiate sedative effects and increase acetaminophen-induced liver toxicity 1
  • Erythromycin and cimetidine may prolong sedation with midazolam 1
• Relevant diseases and physical abnormalities: genetic syndromes, neurologic impairments increasing airway obstruction risk, obesity, snoring or obstructive sleep apnea (OSA), cervical spine instability 1
• Pregnancy status in menarchal females (up to 1% presenting for general anesthesia are pregnant) 1
• Previous anesthesia history and any complications or unexpected responses 1
• Family history related to anesthesia (malignant hyperthermia, pseudocholinesterase deficiency, muscular dystrophy) 1

Critical Airway Assessment

• Focused airway evaluation: tonsillar hypertrophy, abnormal anatomy (mandibular hypoplasia), high Mallampati score (ability to visualize only hard palate or tip of uvula) 1
• Appropriately sized airway equipment must be immediately available 1

Special Population Considerations

Obstructive Sleep Apnea Patients:

• Children with severe OSA have altered mu receptors and require one-third to one-half the typical opioid doses 1
• Lower titrated opioid doses should be used in this population 1

Obese Patients:

• Particularly vulnerable to aorto-caval compression 1
• Vascular access should be established early, especially with BMI >40 kg/m² 1
• Increased risk of difficult airway management and central neuraxial blockade 1

Mandatory Monitoring Standards

Minimum Monitoring Requirements

For all general anesthesia cases: 1

• ECG monitoring
• Pulse oximetry (SpO₂)
• Non-invasive blood pressure (NIBP)
• Capnography (must begin before induction and continue until airway device removed and verbal response re-established)
• Age-adjusted minimum alveolar concentration (MAC) during inhaled anesthetic use

Advanced Monitoring Indications

Processed EEG (pEEG) monitoring is mandatory when: 1

• Total intravenous anesthesia (TIVA) is administered with neuromuscular blocking drugs
• Should start before induction and continue until full recovery from neuromuscular blockade is confirmed
• Should be considered for high-risk patients and during inhalational anesthesia

Quantitative neuromuscular monitoring is mandatory whenever: 1

• Neuromuscular blocking drugs are administered
• Must continue from before initiation through recovery until train-of-four ratio >0.9 is confirmed

Direct arterial pressure monitoring is essential when: 2

• Manipulating systemic pressure with vasoactive agents
• Transducer should be placed at the level of the tragus for neurosurgical procedures 2

Personnel and Equipment Requirements

Staffing Requirements

• At least one individual capable of establishing a patent airway and providing positive pressure ventilation must be present in the procedure room 1
• A team member trained in recognition and treatment of airway complications (apnea, laryngospasm, airway obstruction), opening the airway, suctioning secretions, and performing bag-valve-mask ventilation 1
• A team member with skills to establish intravascular access 1
• A team member with skills to provide chest compressions 1

Equipment Requirements

• Suction, advanced airway equipment, positive pressure ventilation device, and supplemental oxygen immediately available and in good working order 1
• Functional defibrillator or automatic external defibrillator immediately available 1
• Individual or service with advanced life support skills (tracheal intubation, defibrillation, resuscitation medications) immediately available 1

Anesthetic Drug Administration

Induction Agents

Propofol administration: 3

• Dosage should be individualized and titrated to desired effect
• Elderly, debilitated, or ASA-PS III-IV patients require approximately 80% of usual adult dosage
• Rapid bolus administration should not be used for MAC sedation in these populations

Inhalational agents: 4

• Isoflurane and other halogenated anesthetics should only be administered in adequately equipped environments by those qualified by training and experience
• Can react with desiccated CO₂ absorbents to produce carbon monoxide; replace absorbent if desiccation suspected

Drug Titration Principles

When using sedative/analgesic medications intended for general anesthesia: 1

• Administer intravenous medications in small, incremental doses or by infusion, titrating to desired endpoints
• Allow sufficient time between doses for peak effect assessment before subsequent administration
• For non-intravenous routes (oral, rectal, intramuscular, transmucosal), allow sufficient time for absorption and peak effect before supplementation

Critical drug interaction: 1

• Combinations of sedative and analgesic agents cause respiratory depression and airway obstruction
• Appropriately reduce the dose of each component
• Knowledge of each drug's onset time, peak response, and duration is essential

Physiologic Management

Cerebral Physiology (Neurosurgical Procedures)

Maintain optimal cerebral physiology by ensuring: 2

• Euvolemia
• Normotension (or blood pressure targets specific to neurosurgical condition)
• Isotonicity
• Normoglycemia
• Mild hypocapnia (avoid profound hypocapnia unless specifically indicated for brain swelling control)

Respiratory Management

If hypoxemia, significant hypoventilation, or apnea develops: 1

1. Encourage or physically stimulate patient to breathe deeply
2. Administer supplemental oxygen
3. Provide positive pressure ventilation if spontaneous ventilation is inadequate

Reversal Agents

Specific antagonists must be immediately available: 1

• Naloxone for opioid reversal (effectively reverses respiratory depression and increases alertness)
• Flumazenil for benzodiazepine reversal (effectively antagonizes sedation within 15 minutes and shortens recovery times)
• Use reversal agents when airway control, spontaneous ventilation, or positive pressure ventilation is inadequate

Recovery and Discharge

Monitoring During Recovery

• Monitor ventilation and circulation at regular intervals (every 5-15 minutes) until patients are suitable for discharge 1
• Capnography continues until artificial airway is removed and patient responds to verbal contact 1

Discharge Criteria

• Design discharge criteria to minimize risk of central nervous system or cardiorespiratory depression after discharge from trained personnel observation 1
• If local anesthetic agents were applied to the airway, laryngeal reflexes may be depressed for up to one hour; patients should not drink during this period due to aspiration risk 1

Common Pitfalls and Safety Considerations

Drug-Related Risks

• Propofol in ICU sedation: Administration should not exceed 4 mg/kg/hour unless benefits outweigh risks 3
• Abrupt discontinuation of propofol prior to weaning may result in rapid awakening with anxiety, agitation, and resistance to mechanical ventilation 3

Pediatric Considerations

• Neurotoxicity concern: Repeated or prolonged use of general anesthetic or sedation drugs in children younger than 3 years may have negative effects on developing brains 4
• Discuss benefits, risks, timing, and duration with parents and caregivers 4

Quality and Safety Processes

• Create and implement quality improvement processes based on established reporting protocols for adverse events and unsatisfactory sedation 1
• Strengthen patient safety culture through team training, simulation drills, and checklist implementation 1
• Create emergency response plan for activating code blue team or emergency medical response system 1