1. Malignant hyperthermia - triggering agents, early signs (rising ETCO2, tachycardia, masseter spasm), dantrolene protocol, post-crisis care
2. Anaphylaxis under anaesthesia - triggers (NMBAs, antibiotics, latex, chlorhexidine), recognition (masked by anaesthesia), epinephrine-led resuscitation
3. Intraoperative cardiac arrest - causes specific to the anaesthetized patient, modified ACLS considerations, high-risk phases (induction, positioning, embolism)
4. Difficult/failed airway and "can't intubate, can't oxygenate" - algorithms, rescue techniques, cricothyrotomy
5. Local anesthetic systemic toxicity (LAST) - lipid emulsion therapy, seizure/arrhythmia management
6. Operating room fire - the fire triad, prevention, the "stop, remove, extinguish" drill
7. Massive hemorrhage / transfusion reaction - massive transfusion protocols, TRALI/TACO, DIC
8. Venous air/gas embolism
9. Equipment and power/gas supply failure - loss of oxygen pipeline, ventilator failure, backup ventilation
10. Awareness under anesthesia and equipment/monitor failure crises
11. Mass casualty, disaster, and CBRN (chemical/biological/radiological/nuclear) events - triage and anesthesia resource allocation in disasters

1. Malignant hyperthermia - triggering agents, early signs (rising ETCO2, tachycardia, masseter spasm), dantrolene protocol, post-crisis care
2. Anaphylaxis under anaesthesia - triggers (NMBAs, antibiotics, latex, chlorhexidine), recognition (masked by anaesthesia), epinephrine-led resuscitation
3. Intraoperative cardiac arrest - causes specific to the anaesthetized patient, modified ACLS considerations, high-risk phases (induction, positioning, embolism)
4. Difficult/failed airway and "can't intubate, can't oxygenate" - algorithms, rescue techniques, cricothyrotomy
5. Local anesthetic systemic toxicity (LAST) - lipid emulsion therapy, seizure/arrhythmia management
6. Operating room fire - the fire triad, prevention, the "stop, remove, extinguish" drill
7. Massive hemorrhage / transfusion reaction - massive transfusion protocols, TRALI/TACO, DIC
8. Venous air/gas embolism
9. Equipment and power/gas supply failure - loss of oxygen pipeline, ventilator failure, backup ventilation
10. Awareness under anesthesia and equipment/monitor failure crises
11. Mass casualty, disaster, and CBRN (chemical/biological/radiological/nuclear) events - triage and anesthesia resource allocation in disasters

Anaesthesia in Calamitous Situations

1. Malignant Hyperthermia (MH)

• Autosomal dominant defect in the ryanodine receptor (RYR1) causing uncontrolled sarcoplasmic calcium release
• Triggered by volatile anaesthetics and succinylcholine
• Earliest reliable sign: unexplained rising end-tidal CO2, followed by tachycardia, muscle rigidity/masseter spasm, hyperthermia, and metabolic/respiratory acidosis
• Treatment: stop triggering agents immediately, hyperventilate with 100% O2, give dantrolene (stabilizes the sarcoplasmic reticulum and halts calcium release), active cooling, treat hyperkalemia and arrhythmias
• Source: Miller's Anesthesia, 10e and Miller's Review of Orthopaedics, 9e

2. Anaphylaxis Under Anaesthesia

• Recognition is harder because the patient is unconscious - presents as sudden hypotension, tachycardia (or bradycardia), bronchospasm, and flushing/rash, often masked by drapes
• Common triggers: neuromuscular blocking agents, antibiotics, latex, chlorhexidine
• First-line treatment is epinephrine, 0.01 mg/kg of 1:1000 (1 mg/mL) IM, max 0.5 mg in adults / 0.3 mg in children - IV titrated boluses are used if there is IV access and severe hypotension
• Source: Miller's Anesthesia, 10e

3. Cannot Intubate, Cannot Oxygenate (CICO)

• The most feared airway emergency; occurs when both intubation and bag-mask/supraglottic oxygenation fail
• Management follows Difficult Airway Society/ASA algorithms: call for help early, attempt a second-generation supraglottic device, then proceed promptly to front-of-neck access (cricothyrotomy with a scalpel-bougie technique or large-bore cannula plus jet ventilation) rather than repeated failed laryngoscopy attempts
• Reversal agents (sugammadex) can be considered but should not delay definitive airway rescue
• Source: Barash Clinical Anesthesia, 9e; Tintinalli's Emergency Medicine; Roberts and Hedges' Clinical Procedures

4. Local Anesthetic Systemic Toxicity (LAST)

• Occurs from accidental intravascular injection or absorption of local anaesthetic during regional/neuraxial blocks
• CNS signs (perioral numbness, seizures, unconsciousness) usually precede cardiovascular collapse (arrhythmias, hypotension, cardiac arrest), though cardiovascular collapse can be the first sign with bupivacaine
• Treatment: stop the local anaesthetic, airway/oxygenation, benzodiazepines for seizures, and 20% lipid emulsion (Intralipid) - typically a 1.5 mL/kg bolus followed by infusion, per ASRA practice advisory; prolonged CPR may be needed since recovery can take longer than a standard arrest
• Source: Barash Clinical Anesthesia, 9e (ASRA advisory); Morgan and Mikhail's Clinical Anesthesiology, 7e

5. Operating Room / Airway Fire

• Requires the fire triad: fuel (drapes, ET tubes, alcohol-based preps), oxidizer (oxygen/nitrous oxide), and an ignition source (laser, cautery, static)
• Airway/head-and-neck and laser cases carry the highest risk
• Response drill: stop the procedure, remove the burning material/tube, disconnect the gas source, extinguish (saline/water or CO2 extinguisher), then resume ventilation and reassess the airway for thermal injury
• Prevention: use lowest effective FiO2, allow prep solutions to dry, coordinate with the surgical team before using ignition sources
• Source: Barash Clinical Anesthesia, 9e; Morgan and Mikhail's Clinical Anesthesiology, 7e; Sabiston Textbook of Surgery

6. Other calamitous categories covered in Miller's

• Intraoperative cardiac arrest - modified resuscitation considerations in the anaesthetized/paralyzed patient
• Venous air/gas embolism
• Massive haemorrhage and transfusion crises (massive transfusion protocol, TRALI/TACO, DIC)
• Equipment, power, or gas-supply failure - loss of pipeline oxygen, ventilator failure, backup self-inflating bag ventilation
• Mass casualty, disaster response, and CBRN (chemical/biological/radiological/nuclear) events - triage-based anaesthesia resource allocation, personal protective equipment, decontamination protocols (Miller's 10e, Section IV chapters on emergency preparedness and disaster response)

Underlying principle across all of these