Home Quick Dose Pre-Op Clinical Calculators Crisis Protocols IOH Predictor Difficult Airway Informed Consent
Emergency Reference

Crisis Protocols

Evidence-based, step-by-step management for anesthesia emergencies. Quick access to critical protocols when seconds count.

Life-Threatening / Cardiac

Malignant Hyperthermia 5 refs

Hypermetabolic crisis triggered by volatile anesthetics or succinylcholine

Immediate Call Help

Immediate Actions

  1. STOP triggers immediately: Discontinue all volatile anesthetics and succinylcholine1
  2. Call for help: Activate MH emergency protocol, assign roles2
  3. Hyperventilate with 100% O₂: 2-3× normal minute ventilation to eliminate CO₂1
  4. Give dantrolene immediately: See dosing below2
💊 Dantrolene Dosing2
Initial: 2.5 mg/kg IV rapid push (reconstitute each 20mg vial with 60mL sterile water)
Repeat: 1 mg/kg boluses every 5-10 min until signs resolve
Maximum: Up to 10 mg/kg in acute phase (rarely >10 vials needed initially)
Continuation: 1 mg/kg IV q6h × 24-48h to prevent recrudescence

Supportive Care

  1. Cool the patient: Cold IV saline, ice packs to groin/axilla, cooling blanket. Target temp <38.5°C1,3
  2. Treat hyperkalemia: Insulin/dextrose, calcium chloride, bicarbonate, avoid Ca²⁺ channel blockers with dantrolene3
  3. Manage arrhythmias: Standard ACLS (avoid calcium channel blockers)1
  4. Monitor urine output: Foley catheter, maintain >1 mL/kg/h to prevent myoglobin-induced renal failure3
  5. Labs: ABG, electrolytes, CK, lactate, coags, myoglobin q6h1
📞 MH Hotline
USA: 1-800-MH-HYPER (1-800-644-9737)
Outside USA: +1-315-464-7079
Expert consultant available 24/7 for real-time guidance4
⚠️ Key Points
• Early signs: Unexplained ↑EtCO₂, masseter spasm, tachycardia, hypercarbia refractory to ↑ventilation
• Late signs: Fever, rigidity, rhabdomyolysis, hyperkalemia, acidosis
• Dantrolene can cause profound weakness - prepare for prolonged ventilation
• ICU monitoring × 24-48h minimum (recrudescence occurs in ~25%)5
1 Litman RS, Griggs SM, Dowling JJ, et al. Malignant Hyperthermia Susceptibility and Related Diseases. Anesthesiology. 2018;128(1):159-167. PMID: 29200006
2 MHAUS Emergency Therapy for MH (2022 Update). mhaus.org/managing-a-crisis
3 Rosenberg H, Pollock N, Schiemann A, et al. Malignant hyperthermia: a review. Orphanet J Rare Dis. 2015;10:93. PMID: 26238698
4 Malignant Hyperthermia Association of the United States (MHAUS). 24/7 Emergency Hotline. mhaus.org
5 Larach MG, Brandom BW, Allen GC, et al. Malignant Hyperthermia Deaths Related to Inadequate Temperature Monitoring. Anesthesiology. 2019;130(1):40-51. PMID: 30475256

Cardiac Arrest (ACLS) 4 refs

Immediate CPR and rhythm-specific advanced life support

Immediate Call Help

Universal Steps (All Rhythms)

  1. Start CPR immediately: 100-120 compressions/min, depth 2-2.4 inches, minimize interruptions1
  2. Call for help / Code Blue
  3. Attach defibrillator/monitor: Identify rhythm
  4. Secure airway: ETT or supraglottic device + capnography (target EtCO₂ >10 mmHg)1
  5. IV/IO access: Establish vascular access for medications
  6. Consider reversible causes (H's and T's)2

Shockable Rhythms (VF/pVT)

  1. Defibrillate: Biphasic 120-200J (or manufacturer recommendation), resume CPR immediately × 2 min1
  2. After 2nd shock: Epinephrine 1 mg IV/IO q3-5min1
  3. After 3rd shock: Amiodarone 300 mg IV/IO (or lidocaine 1-1.5 mg/kg if amio unavailable)1
  4. Continue CPR + defibrillation every 2 min

Non-Shockable Rhythms (PEA/Asystole)

  1. High-quality CPR × 2 min1
  2. Epinephrine 1 mg IV/IO immediately, then q3-5min1
  3. Consider atropine 1 mg IV if slow PEA (rate <60), may repeat to total 3 mg
  4. Treat reversible causes aggressively (see H's and T's below)2
💊 Key Medications1
Epinephrine: 1 mg (1:10,000) IV/IO every 3-5 minutes
Amiodarone: 300 mg IV/IO first dose, then 150 mg second dose
Lidocaine (alternative): 1-1.5 mg/kg first dose, then 0.5-0.75 mg/kg
Sodium bicarbonate: 1 mEq/kg (for hyperkalemia, TCA overdose, prolonged arrest)
🔍 H's and T's (Reversible Causes)2
H's: Hypovolemia, Hypoxia, H⁺ (acidosis), Hyper/hypokalemia, Hypothermia
T's: Tension pneumothorax, Tamponade (cardiac), Toxins, Thrombosis (coronary/pulmonary)
⚠️ Anesthesia-Specific Considerations
• Turn off volatile anesthetics during arrest
• Consider anesthesia-specific causes: local anesthetic toxicity (give lipid emulsion), hyperkalemia from succinylcholine, pneumothorax from line placement, total spinal3
• Continue CPR during transfer to ICU if needed
• Document ROSC time, rhythm changes, total epi/defib doses4
1 Panchal AR, et al. Part 3: Adult Basic and Advanced Life Support. 2020 AHA Guidelines. Circulation. 2020;142(16_suppl_2):S366-S468. PMID: 33081529
2 Link MS, et al. Part 7: Adult Advanced Cardiovascular Life Support. Circulation. 2015;132(18 Suppl 2):S444-64. PMID: 26472995
3 Neal JM, et al. Anesthesia-Related Cardiac Arrest: A Registry Analysis. Anesthesiology. 2014;120(4):829-838. PMID: 24694841
4 Soar J, et al. European Resuscitation Council Guidelines. Resuscitation. 2021;161:98-114. PMID: 33773831

Anaphylaxis 4 refs

Severe IgE-mediated hypersensitivity reaction with cardiovascular/airway collapse

Immediate Call Help

Immediate Management

  1. STOP suspected trigger: Antibiotics, NMBs, latex, colloids are most common1
  2. Call for help
  3. Epinephrine IM immediately: 0.3-0.5 mg (0.3-0.5 mL of 1:1000) into anterolateral thigh, repeat q5-15min PRN2
  4. 100% O₂: Maintain airway, consider early intubation if upper airway edema2
  5. Aggressive fluid resuscitation: 20-50 mL/kg crystalloid rapidly for refractory hypotension2
💊 Epinephrine Dosing2
IM (first-line): 0.3-0.5 mg (1:1000) into thigh, repeat q5-15min
IV bolus (severe/arrest): 10-100 mcg (0.01-0.1 mg) slow push, titrate to effect
IV infusion (refractory): 0.05-0.5 mcg/kg/min, titrate to BP/HR
Pediatric IM: 0.01 mg/kg (max 0.5 mg)

Adjunct Therapies

  1. H1 blocker: Diphenhydramine 25-50 mg IV slowly2
  2. H2 blocker: Famotidine 20 mg IV or ranitidine 50 mg IV2
  3. Corticosteroids: Methylprednisolone 1-2 mg/kg IV (prevents late-phase reaction)2
  4. Bronchodilators: Albuterol for persistent bronchospasm
  5. Glucagon (if on β-blockers): 1-2 mg IV (epinephrine may be ineffective)2
🩺 Diagnostic Criteria (2 or more)2
• Skin/mucosal: Urticaria, angioedema, flushing
• Respiratory: Bronchospasm, wheezing, stridor, dyspnea, ↓SpO₂
• Cardiovascular: Hypotension (SBP <90 or >30% drop), tachycardia, arrhythmia, collapse
• GI: Cramping, vomiting, diarrhea
⚠️ Key Considerations
• Common triggers: NMBs (rocuronium, succinylcholine), antibiotics (cephalosporins, penicillins), latex, chlorhexidine3
• Confirm diagnosis: Send tryptase levels (draw immediately, then 1-2h and 24h later)4
• Biphasic reactions occur in 20% - observe ≥4-6h minimum, admit if severe2
• Document reaction in chart and advise patient to see allergist
• Refractory hypotension: Consider methylene blue 1-2 mg/kg for vasoplegia
1 Dewachter P, et al. Perioperative Anaphylaxis. Anesthesiology. 2009;111(5):1141-1150. PMID: 19858877
2 Shaker MS, et al. Anaphylaxis: A 2020 Practice Parameter Update. Ann Allergy Asthma Immunol. 2020;125(4):346-373. PMID: 32846301
3 Mertes PM, et al. Reducing the Risk of Anaphylaxis During Anesthesia. J Allergy Clin Immunol Pract. 2020;8(8):2544-2555. PMID: 32505781
4 Fisher MM, Baldo BA. Mast Cell Tryptase in Anaesthetic Anaphylactoid Reactions. Br J Anaesth. 1998;80(1):26-29. PMID: 9505773

Local Anesthetic Systemic Toxicity (LAST) 3 refs

CNS/cardiac toxicity from systemic absorption of local anesthetics

Immediate Call Help

Immediate Actions

  1. STOP local anesthetic injection
  2. Call for help: Get lipid emulsion (Intralipid 20%)1
  3. Airway management: 100% O₂, ventilate if needed, suppress seizures
  4. Give lipid emulsion immediately (see dosing below) - DO NOT DELAY1
  5. If cardiac arrest: Start CPR, consider prolonged resuscitation (LAST arrest can require >1h CPR)2
💊 Lipid Emulsion 20% (Intralipid) Dosing1
Bolus: 1.5 mL/kg IV (lean body weight) over 1 minute (~100 mL for 70 kg adult)
Infusion: 0.25 mL/kg/min (~18 mL/min for 70 kg = ~500 mL bag over 30 min)
Repeat bolus: If cardiovascular instability persists after 5 min, give up to 2 more boluses (same dose)
Increase infusion: Double rate to 0.5 mL/kg/min if BP remains unstable
Maximum dose: ~10 mL/kg over first 30 minutes

Seizure Management

  1. Benzodiazepines: Midazolam 1-2 mg IV or lorazepam 1-2 mg IV
  2. AVOID propofol in large doses (additional lipid load, myocardial depression)
  3. Small-dose propofol OK if lipid already given and seizures refractory
🩺 Signs of LAST
Early CNS: Circumoral numbness, metallic taste, tinnitus, confusion, agitation
Severe CNS: Seizures, loss of consciousness
Cardiac: Bradycardia, hypotension, arrhythmias (wide QRS), asystole, PEA1
Note: Cardiac toxicity can occur WITHOUT preceding CNS symptoms (especially bupivacaine)
⚠️ Critical Points
• Lipid emulsion is PRIMARY treatment - give early, don't wait for arrest1
• Bupivacaine/ropivacaine are more cardiotoxic than lidocaine/mepivacaine
• Max doses: Bupivacaine 2.5 mg/kg plain, 3 mg/kg with epi; Lidocaine 5 mg/kg plain, 7 mg/kg with epi3
• Post-resuscitation: Monitor ≥4-6h (cardiac arrest patients → ICU), watch for pancreatitis from lipid load
1 Neal JM, et al. ASRA Practice Advisory on Local Anesthetic Systemic Toxicity. Reg Anesth Pain Med. 2018;43(2):113-123. PMID: 29356773
2 Gitman M, Barrington MJ. Local Anesthetic Systemic Toxicity: A Review of Recent Case Reports. Reg Anesth Pain Med. 2018;43(2):124-130. PMID: 29095244
3 American Society of Regional Anesthesia and Pain Medicine. Checklist for Treatment of Local Anesthetic Systemic Toxicity. Reg Anesth Pain Med. 2012;37(1):16-18

High/Total Spinal Anesthesia 3 refs

Excessive cephalad spread of neuraxial anesthetic causing cardiorespiratory compromise

Immediate Call Help

Immediate Actions - ABC Approach

  1. Airway: Secure airway immediately if respiratory distress. Intubate if apneic or unable to protect airway1
  2. Breathing: Positive pressure ventilation with 100% O₂ (bag-mask or intubation)1
  3. Circulation: Treat hypotension and bradycardia (see below)2
  4. Position: Supine or slight Trendelenburg (controversy: may worsen vs improve symptoms)1
  5. Reassure patient: If awake, explain that this is temporary and reversible

Hemodynamic Management

  1. Hypotension: Phenylephrine 50-200 mcg IV boluses or ephedrine 5-10 mg IV boluses2
  2. Severe hypotension: Epinephrine 10-100 mcg IV boluses (or start infusion)2
  3. Bradycardia: Atropine 0.4-1 mg IV or glycopyrrolate 0.2-0.4 mg IV2
  4. Severe bradycardia/arrest: Epinephrine 1 mg IV, start CPR if pulseless2
  5. Volume: Rapid IV fluid bolus 500-1000 mL crystalloid1
💊 Key Medications2
Phenylephrine: 50-200 mcg IV boluses (or 0.5-1 mcg/kg/min infusion)
Ephedrine: 5-10 mg IV boluses
Epinephrine (severe): 10-100 mcg IV boluses or 0.01-0.1 mcg/kg/min infusion
Atropine: 0.4-1 mg IV (for bradycardia)
Glycopyrrolate: 0.2-0.4 mg IV (alternative for bradycardia)
🔍 Clinical Features1
Sensory level: T1-T4 (high spinal) vs C3-C8 (total spinal)
Motor: Upper extremity weakness, difficulty breathing, inability to speak
Cardiovascular: Hypotension, bradycardia (Bezold-Jarisch reflex)
Respiratory: Dyspnea, respiratory arrest (phrenic nerve paralysis C3-C5)
Neurologic: Unconsciousness (if brainstem affected), dilated pupils, nystagmus
⚠️ Key Points
• Self-limited: Block will spontaneously regress over 1-3 hours3
• Early intubation: Don't wait for complete respiratory arrest - intubate early if distress
• Epinephrine early: Don't hesitate to use epi if severe hypotension/bradycardia
• Avoid sedation: Patient may already be unconscious from brainstem anesthesia
• Document sensory level: Check bilateral sensation to assess block height
⚠️ Prevention & Risk Factors
Risk factors for high spinal:
• Excessive local anesthetic dose or volume
• Rapid injection or patient positioning (head-down)
• Inadvertent subdural or subarachnoid injection during epidural
• Short patient height, pregnancy (reduced CSF volume)
• Barbotage technique1

Prevention: Use appropriate dose for patient height, test dose, incremental dosing for epidurals, careful patient positioning
🔍 Differential Diagnosis
• Local anesthetic systemic toxicity (LAST): CNS excitation (seizures) before cardiac arrest
• Vasovagal syncope: Bradycardia + hypotension but normal respirations
• Anaphylaxis: Bronchospasm, urticaria, angioedema
• Myocardial infarction: ECG changes, chest pain
• Pulmonary embolism: Sudden hypoxia, tachycardia
1 Reina MA, et al. Clinical implications of epidural fat in the spinal canal: a scanning electron microscopic study. Acta Anaesthesiol Scand. 2009;53(5):641-647. PMID: 19419359
2 Pollard JB. Cardiac arrest during spinal anesthesia: common mechanisms and strategies for prevention. Anesth Analg. 2001;92(1):252-256. PMID: 11133637
3 Auroux P, et al. Total spinal anesthesia after epidural test dose. Anesthesiology. 2000;92(5):1514-1516. PMID: 10781306

Venous Air Embolism (VAE) 4 refs

Air entrainment into venous system causing cardiovascular and/or neurologic compromise

Immediate Call Help

Immediate Actions

  1. Notify surgeon: STOP surgery, flood field with saline, apply bone wax to exposed bone1
  2. 100% O₂: Discontinue N₂O immediately (if used), switch to FiO₂ 1.01
  3. Position: Lower surgical site below heart level if possible (reverse Trendelenburg → supine or head down)2
  4. Attempt aspiration: If central line in place, aspirate from distal port to remove air1
  5. Support hemodynamics: IV fluids, vasopressors/inotropes as needed (see below)2

Advanced Management

  1. Hemodynamic support: Phenylephrine, ephedrine, or epinephrine as needed for hypotension2
  2. CPR if cardiac arrest: Chest compressions may help break up air lock and disperse air3
  3. Consider hyperbaric oxygen: If neurologic deficits persist (paradoxical embolism)4
  4. Durant maneuver (controversial): Left lateral decubitus + Trendelenburg to trap air in right atrium2
  5. TEE/TTE: If available, can visualize air in heart chambers and assess severity1
💊 Hemodynamic Support2
Phenylephrine: 50-200 mcg IV boluses or infusion 0.5-1 mcg/kg/min
Ephedrine: 5-10 mg IV boluses
Epinephrine: 10-100 mcg IV boluses (or 0.01-0.1 mcg/kg/min infusion) for severe hypotension
Atropine: 0.4-1 mg IV if bradycardic
IV fluids: Rapid bolus 500-1000 mL crystalloid
🔍 Clinical Signs (by Monitor Sensitivity)1
Most sensitive (earliest):
• Precordial Doppler: "Mill wheel" murmur (detects 0.25 mL air)
• TEE: Visualize air in heart chambers
• Sudden ↓EtCO₂ (dead space ventilation)

Moderate sensitivity:
• Hypotension, tachycardia
• Hypoxia (↓SpO₂)
• Arrhythmias

Late/severe:
• Cardiovascular collapse
• Cardiac arrest (air lock in RV outflow)
⚠️ High-Risk Procedures & Prevention
High-risk surgeries:
• Sitting position craniotomy (most common)
• Posterior fossa surgery
• Neurosurgery with head elevated >15°
• Spine surgery (especially cervical)
• Laparoscopy, hepatic resection, cesarean section1

Prevention: Avoid N₂O, optimize patient positioning (minimize head elevation), adequate hydration, ensure good communication with surgeon, consider central venous catheter for aspiration, use precordial Doppler or TEE monitoring
⚠️ Paradoxical Air Embolism (PAE)
• Occurs when air crosses from right → left heart via PFO (present in ~25% of population)4
• Results in stroke, MI, or organ ischemia
• Higher risk with sitting position (negative intrathoracic pressure)
• Signs: Sudden neurologic deficit, ST-segment changes on ECG
• Management: Immediate 100% O₂, hemodynamic support, consider hyperbaric oxygen therapy
• Screen high-risk patients for PFO with TEE or bubble study (controversial)
1 Mirski MA, et al. Diagnosis and treatment of vascular air embolism. Anesthesiology. 2007;106(1):164-177. PMID: 17197859
2 Shaikh N, Ummunisa F. Acute management of vascular air embolism. J Emerg Trauma Shock. 2009;2(3):180-185. PMID: 20009308
3 Vesely TM, et al. Air embolism during insertion of central venous catheters. J Vasc Interv Radiol. 2001;12(11):1291-1295. PMID: 11698626
4 Muth CM, Shank ES. Gas embolism. N Engl J Med. 2000;342(7):476-482. PMID: 10675429

Hyperkalemia 3 refs

Life-threatening elevation in serum potassium causing cardiac arrhythmias and arrest

Immediate Call Help

Immediate Actions (3-Step Approach)

  1. STEP 1 - Membrane stabilization (fastest): Calcium chloride 10% 10-20 mL IV over 2-5 min OR calcium gluconate 10% 30-60 mL IV1
  2. STEP 2 - Shift K⁺ intracellularly: Insulin 10 units IV + dextrose 25 g (D50W 50 mL) IV push1
  3. STEP 3 - Remove K⁺ from body: Diuretics (furosemide 40-80 mg IV) if renal function intact2
  4. Additional shift therapy: Albuterol 10-20 mg nebulized (lowers K⁺ by 0.5-1 mEq/L)1
  5. If cardiac arrest: Start CPR, repeat calcium, consider emergency dialysis3
💊 Treatment Protocol (K⁺ >6.5 mEq/L or ECG changes)1
1. Calcium chloride 10%: 10-20 mL (1-2 g) IV over 2-5 min (onset 1-3 min, duration 30-60 min) - OR -
1. Calcium gluconate 10%: 30-60 mL (3-6 g) IV over 2-5 min (less tissue necrosis if extravasates)
2. Regular insulin: 10 units IV + D50W 50 mL (25 g dextrose) IV push (onset 15-30 min, duration 4-6 h)
3. Albuterol: 10-20 mg (2-4 mL of 0.5% solution) nebulized over 10 min (onset 30 min, lowers K⁺ 0.5-1 mEq/L)
4. Sodium bicarbonate: 50-100 mEq IV (controversial, mainly for acidosis)
5. Furosemide: 40-80 mg IV (if renal function intact)
6. Kayexalate/Patiromer: NOT for acute management (slow onset, hours to days)
🔍 ECG Changes by Severity1
Mild (K⁺ 5.5-6.5): Peaked, narrow T waves
Moderate (K⁺ 6.5-8.0): PR prolongation, P wave flattening/loss, QRS widening
Severe (K⁺ >8.0): Sine wave pattern, ventricular fibrillation, asystole
⚠️ Anesthesia-Specific Causes
• Succinylcholine: Especially in burns, crush injuries, denervation, prolonged immobility, neuromuscular disease2
• Massive transfusion: Stored blood has high K⁺ (up to 50 mEq/L in old units)
• Tourniquet release: Sudden K⁺ release from ischemic limb
• Tumor lysis syndrome: Chemotherapy, large tumor burden
• Medications: ACE-I, ARBs, K⁺-sparing diuretics, NSAIDs
• Renal failure: Most common chronic cause
⚠️ Key Points
• Calcium first: Most important immediate treatment - stabilizes cardiac membrane
• Don't mix calcium with bicarb: Forms precipitate (give via separate IV)
• Monitor glucose: After insulin/dextrose therapy (risk of hypoglycemia 4-6h later)
• Repeat labs: Check K⁺ q2-4h until normalized
• Emergency dialysis: Consider if K⁺ >7.5 mEq/L, refractory, or cardiac arrest3
• Avoid succinylcholine: If hyperkalemia suspected or patient at risk
🔍 Pseudohyperkalemia (Lab Error)
• Hemolysis: Most common cause of falsely elevated K⁺ (check sample for pink/red tint)
• Fist clenching: During phlebotomy
• Prolonged tourniquet time
• Thrombocytosis or leukocytosis: Cell lysis in sample
• If suspected: Repeat with non-hemolyzed sample, correlate with ECG changes
1 Hollander-Rodriguez JC, Calvert JF Jr. Hyperkalemia. Am Fam Physician. 2006;73(2):283-290. PMID: 16445274
2 Thapa S, Brull SJ. Succinylcholine-Induced Hyperkalemia in Patients with Renal Failure. Anesth Analg. 2000;91(5):1140-1145. PMID: 11049897
3 Alfonzo AV, et al. Potassium disorders-clinical spectrum and emergency management. Resuscitation. 2006;70(1):10-25. PMID: 16600469

PRIS (Propofol Infusion Syndrome) 4 refs

Rare but life-threatening syndrome from prolonged high-dose propofol infusion

Immediate Call Help

Immediate Actions

  1. STOP propofol immediately: Discontinue infusion - this is the MOST important intervention1
  2. Switch sedation: Use alternative sedative (midazolam, dexmedetomidine, or ketamine)1
  3. Supportive care: Hemodynamic support with vasopressors/inotropes as needed2
  4. Labs: ABG, lactate, CK, troponin, lipase, electrolytes (especially K⁺), triglycerides, liver function1
  5. Consider hemodialysis or ECMO: If refractory metabolic acidosis or cardiac failure3

Specific Management

  1. Metabolic acidosis: Bicarbonate therapy (controversial), treat underlying cause2
  2. Hyperkalemia: Standard hyperkalemia protocol (calcium, insulin/dextrose, albuterol)2
  3. Cardiac dysfunction: Inotropes (dobutamine, milrinone), avoid further myocardial stress2
  4. Rhabdomyolysis: Aggressive fluid resuscitation, maintain urine output >1 mL/kg/h1
  5. Renal replacement therapy: If severe metabolic derangement or renal failure3
💊 Alternative Sedation Options1
Midazolam: Load 0.05-0.1 mg/kg IV, then 0.05-0.2 mg/kg/h infusion
Dexmedetomidine: Load 1 mcg/kg over 10 min, then 0.2-0.7 mcg/kg/h infusion
Ketamine: 0.5-1 mg/kg bolus, then 0.5-1 mg/kg/h infusion
Volatile anesthetics: Consider if in OR setting (sevoflurane, isoflurane)
🔍 Classic Pentad of PRIS1
1. Metabolic acidosis: Severe, refractory (pH <7.2, lactate >5 mmol/L)
2. Rhabdomyolysis: Elevated CK (often >5000 U/L), myoglobinuria
3. Cardiac failure: Bradycardia → heart block → asystole, dilated cardiomyopathy
4. Renal failure: Acute kidney injury, often requiring dialysis
5. Hypertriglyceridemia/hepatomegaly: Lipemic serum, fatty liver
⚠️ Risk Factors1,4
Classic triad:
• High dose: >4 mg/kg/h (67 mcg/kg/min) for >48-72 hours
• Young age: Children > adults (but can occur in adults)
• Critical illness: Sepsis, traumatic brain injury, status epilepticus

Other risk factors:
• Catecholamine or steroid co-administration
• Inadequate carbohydrate intake
• Mitochondrial disease or inborn errors of metabolism
⚠️ Early Warning Signs (Monitor Daily)
• Unexplained metabolic acidosis (base deficit >−10, lactate >2 mmol/L)
• ↑ Triglycerides (>400 mg/dL) - lipemic serum
• ↑ CK (>1000 U/L) or myoglobinuria
• New ECG changes: Bradycardia, Brugada-like pattern, QRS widening, ST elevation
• ↑ Troponin without MI
• Hepatomegaly or ↑ liver enzymes

If ANY early signs → strongly consider switching sedation4
🔍 Prevention Strategies
• Limit dose: Keep propofol <4 mg/kg/h (<67 mcg/kg/min) if prolonged infusion needed4
• Limit duration: Avoid continuous infusion >48-72 hours
• Monitor: Daily CK, triglycerides, lactate if high-dose or prolonged infusion
• Alternative sedation: Use multimodal approach (combine with dexmedetomidine, ketamine, or benzodiazepines to reduce propofol dose)
• Adequate nutrition: Ensure carbohydrate intake (failure of fat oxidation is part of pathophysiology)
⚠️ Prognosis
• Mortality: ~30-60% once fully developed (cardiac arrest is often terminal)3
• Key to survival: Early recognition and immediate cessation of propofol
• Recovery: If caught early (before cardiac failure), most metabolic abnormalities resolve within 24-72 hours after stopping propofol
1 Krajčová A, et al. Propofol infusion syndrome: a structured review of experimental studies and 153 published case reports. Crit Care. 2015;19:398. PMID: 26563768
2 Otterspoor LC, et al. Update on the Propofol Infusion Syndrome in ICU Management of Patients with Head Injury. Curr Opin Anaesthesiol. 2008;21(5):544-551. PMID: 18784477
3 Mirrakhimov AE, et al. Propofol Infusion Syndrome in Adults: A Clinical Update. Crit Care Res Pract. 2015;2015:260385. PMID: 26078890
4 Roberts RJ, et al. Propofol concentration and the risk of infusion syndrome. Anesth Analg. 2009;109(4):1058-1062. PMID: 19762733

Massive Transfusion Protocol 5 refs

Life-threatening hemorrhage requiring massive blood product replacement

Immediate Call Help

Immediate Actions & Activation

  1. Activate MTP: Call blood bank immediately, activate institutional massive transfusion protocol1
  2. Large-bore IV access: Two 14-16G peripheral IVs or central access (consider rapid infusion device)2
  3. Control hemorrhage: Direct pressure, surgical hemostasis, consider damage control surgery1
  4. Balanced resuscitation (1:1:1 ratio): PRBC : FFP : Platelets in equal proportions3
  5. Tranexamic acid (TXA): Give EARLY if traumatic hemorrhage (within 3 hours of injury)4
💊 Balanced Resuscitation (1:1:1 Ratio)3
PRBC (packed RBCs): 1 unit (~350 mL) raises Hgb ~1 g/dL
FFP (fresh frozen plasma): 1 unit (~250 mL) per 1 unit PRBC
Platelets: 1 apheresis unit (or 6-pack pooled) per 6 units PRBC
Example: 6 PRBC : 6 FFP : 1 platelet apheresis unit
💊 Adjunct Medications4,5
Tranexamic acid (TXA): 1 g IV over 10 min, then 1 g over 8 hours (trauma/obstetric hemorrhage)
Calcium chloride: 1-2 g IV q4-6 units citrated blood (prevent citrate toxicity)
Fibrinogen concentrate: 3-4 g IV if fibrinogen <150 mg/dL (alternative to cryoprecipitate)
Cryoprecipitate: 10 units (1 pool) if fibrinogen <100 mg/dL or ongoing bleeding
Prothrombin complex concentrate (PCC): 25-50 units/kg for warfarin reversal

Monitoring & Labs

  1. Labs q30-60min: CBC, PT/INR, PTT, fibrinogen, ionized calcium, ABG/lactate, TEG/ROTEM if available2
  2. Goals: Hgb >7 g/dL, platelets >50K (>100K if ongoing bleeding/CNS injury), INR <1.5, fibrinogen >150 mg/dL3
  3. Temperature: Maintain normothermia >36°C (use warmer, forced-air warming)2
  4. Acidosis: Correct pH >7.2 (ventilation, bicarbonate if severe metabolic acidosis)2
  5. Hypocalcemia: Maintain ionized Ca²⁺ >1.0 mmol/L (give calcium with citrated blood products)2
🔍 MTP Activation Criteria1
Clinical triggers:
• Hemodynamic instability despite initial resuscitation
• Anticipated transfusion >10 units PRBC in 24h
• >4 units PRBC in 1 hour with ongoing bleeding
• Replacement of ≥50% blood volume in 3 hours

Specific scenarios:
• Trauma with shock (SBP <90, HR >120)
• Ruptured AAA, massive GI bleed, postpartum hemorrhage
• Intraoperative hemorrhage (liver trauma, aortic surgery, placenta accreta)
⚠️ The "Lethal Triad" (Trauma Death Spiral)
1. Hypothermia (<36°C) - worsens coagulopathy, impairs platelet function
2. Acidosis (pH <7.2) - worsens coagulopathy, impairs hemostasis
3. Coagulopathy (INR >1.5, platelets <50K) - perpetuates bleeding2

Prevention is critical: Aggressive warming, early balanced transfusion, damage control surgery, permissive hypotension (SBP 80-90 until hemorrhage control)
⚠️ Complications of Massive Transfusion
• TACO (Transfusion-Associated Circulatory Overload): Pulmonary edema, hypoxia - slow transfusion, diuretics
• TRALI (Transfusion-Related Acute Lung Injury): Noncardiogenic pulmonary edema within 6h - supportive care
• Citrate toxicity: Hypocalcemia (tremor, arrhythmias) - give calcium chloride
• Hyperkalemia: From stored blood (especially old units) - monitor K⁺, treat if >6 mEq/L
• Hypothermia: Use blood warmers, forced-air warming
• Dilutional coagulopathy: Prevented by balanced 1:1:1 resuscitation5
🔍 Special Populations
Obstetric hemorrhage (PPH):
• TXA 1 g IV within 3h of delivery
• Consider recombinant factor VIIa if refractory (off-label)
• Uterotonics: oxytocin, methylergonovine, carboprost, misoprostol

Anticoagulated patients:
• Warfarin → PCC 25-50 units/kg + vitamin K 10 mg IV
• Dabigatran → idarucizumab 5 g IV
• Xa inhibitors (rivaroxaban, apixaban) → andexanet alfa or PCC5
1 Holcomb JB, et al. The Prospective, Observational, Multicenter, Major Trauma Transfusion (PROMMTT) Study. JAMA Surg. 2013;148(2):127-136. PMID: 23560283
2 Spahn DR, et al. The European guideline on management of major bleeding and coagulopathy following trauma. Crit Care. 2019;23(1):98. PMID: 30917843
3 Holcomb JB, et al. Transfusion of plasma, platelets, and red blood cells in a 1:1:1 vs 1:1:2 ratio (PROPPR trial). JAMA. 2015;313(5):471-482. PMID: 25647203
4 CRASH-2 Trial Collaborators. Effects of tranexamic acid on death in trauma patients (CRASH-2). Lancet. 2010;376(9734):23-32. PMID: 20554319
5 Ghadimi K, et al. Perioperative management of the bleeding patient. Br J Anaesth. 2016;117(suppl 3):iii18-iii30. PMID: 27940452

Airway Emergencies

Can't Intubate, Can't Oxygenate (CICO) 2 refs

Life-threatening failure to intubate AND ventilate requiring emergency surgical airway

Immediate Call Help

Immediate Actions - Scalpel Cricothyroidotomy

  1. Declare CICO: Call for help, assign roles1
  2. Position: Extend neck, palpate cricothyroid membrane
  3. Stab incision: Horizontal skin incision through cricothyroid membrane with scalpel (blade #10 or #20)1
  4. Bougie: Insert bougie through membrane into trachea (feel "clicks" of tracheal rings)
  5. Tube: Railroad 6.0 cuffed ETT or tracheostomy tube over bougie into trachea
  6. Confirm: Inflate cuff, ventilate, confirm placement with EtCO₂
⚠️ Key Points
• Scalpel technique preferred over needle cricothyroidotomy (Seldinger kits have high failure rate)2
• Don't delay - permanent brain damage occurs after 3-5 minutes of hypoxia
• If anatomy unclear: Make vertical skin incision, then palpate membrane and make horizontal membrane incision
• Post-procedure: Secure tube, get ENT/surgery consult, chest X-ray
1 Apfelbaum JL, et al. 2022 ASA Practice Guidelines for Management of the Difficult Airway. Anesthesiology. 2022;136(1):31-81. PMID: 34762729
2 Frerk C, et al. Difficult Airway Society Guidelines for Emergency Front-of-Neck Access. Br J Anaesth. 2015;115(6):827-848. PMID: 26556848

Laryngospasm 4 refs

Reflex glottic closure causing complete or partial airway obstruction

Immediate

Immediate Actions

  1. Remove stimulus: Stop surgery, suction oropharynx of blood/secretions1
  2. 100% O₂ with positive pressure: Gentle jaw thrust + CPAP (try 5-10 cm H₂O first)1
  3. Deepen anesthesia: If inadequate depth, give propofol 0.5-1 mg/kg IV2
  4. Larson's maneuver: Firm pressure on "laryngospasm notch" (posterior to mandible angle, anterior to mastoid) while applying jaw thrust3
⚠️ If Laryngospasm Persists (>30 seconds)
Give succinylcholine: 0.1-0.5 mg/kg IV (or 2-4 mg/kg IM if no IV access)2
• Prepare to ventilate and intubate if needed
• Monitor for bradycardia (especially in children) - have atropine ready
💊 Key Dosing2
Propofol (deepen): 0.5-1 mg/kg IV bolus
Succinylcholine (if refractory): 0.1-0.5 mg/kg IV or 2-4 mg/kg IM
Atropine (if bradycardia): 0.01-0.02 mg/kg IV (minimum 0.1 mg)
🔍 Post-Laryngospasm Management
• Monitor for negative-pressure pulmonary edema (NPPE): Occurs in ~0.1% of laryngospasm cases4
• Signs: Pink frothy sputum, decreased SpO₂, crackles on auscultation
• Treatment: Supplemental O₂, PEEP/CPAP, diuretics if needed, rarely intubation
• Monitor oxygenation for 1-2 hours post-event
⚠️ Prevention Strategies
• Extubate deep (under anesthesia) or awake - avoid "light" stage1
• Suction oropharynx thoroughly before emergence (avoid pharyngeal stimulation during light anesthesia)
• Lidocaine 1-1.5 mg/kg IV 2 min before extubation may reduce risk2
• Higher risk: Pediatrics, airway surgery, GERD, recent URI, reactive airway disease
1 Orliaguet GA, et al. Management of laryngospasm in children. Paediatr Anaesth. 2019;29(7):774-780. PMID: 31025445
2 Visvanathan T, et al. Laryngospasm in anaesthesia. Contin Educ Anaesth Crit Care Pain. 2015;15(3):136-141.
3 Larson CP Jr. Laryngospasm--the best treatment. Anesthesiology. 1998;89(5):1293-1294. PMID: 9822034
4 Bhattacharya M, et al. Negative Pressure Pulmonary Edema. Chest. 2016;150(4):927-933. PMID: 27167224

Bronchospasm 4 refs

Acute airway obstruction from smooth muscle constriction and inflammation

Act Fast

Immediate Actions

  1. 100% O₂: Increase FiO₂ to 1.0, ensure adequate oxygenation1
  2. Deepen anesthesia: Increase volatile anesthetic (sevoflurane/isoflurane have bronchodilator effects)1
  3. Rule out mechanical causes: Check for kinked ETT, mucus plug, endobronchial intubation, pneumothorax2
  4. Beta-2 agonist (first-line): Albuterol 4-8 puffs via MDI with spacer into circuit (or 2.5-5 mg nebulized)1

Additional Therapies (if refractory)

  1. Epinephrine: 10-50 mcg IV boluses (or 0.3 mg IM if severe)2
  2. Ketamine: 0.5-1 mg/kg IV bolus (bronchodilator via sympathomimetic effects)3
  3. Magnesium sulfate: 2 g IV over 20 min (smooth muscle relaxation)3
  4. Corticosteroids: Methylprednisolone 1-2 mg/kg IV or hydrocortisone 2-4 mg/kg IV (delayed onset ~6 hours)1
  5. Anticholinergic: Ipratropium 0.5 mg nebulized (adjunct to beta-agonist)1
💊 Key Medications1,2,3
Albuterol (MDI): 4-8 puffs into circuit with spacer, repeat q20min PRN
Albuterol (nebulized): 2.5-5 mg in 3 mL NS
Epinephrine: 10-50 mcg IV boluses (titrate) or 0.3 mg IM if severe
Ketamine: 0.5-1 mg/kg IV bolus, then 0.5-1 mg/kg/h infusion
Magnesium sulfate: 2 g (40 mg/kg peds) IV over 20 minutes
Methylprednisolone: 1-2 mg/kg IV (or hydrocortisone 2-4 mg/kg)
⚠️ Differential Diagnosis
Rule out these mechanical causes first:
• Kinked or obstructed ETT
• Endobronchial intubation (check bilateral breath sounds)
• Mucus plug (consider bronchoscopy/suction)
• Tension pneumothorax
• Pulmonary edema or aspiration
• Anaphylaxis (check for hypotension, urticaria)2
🔍 Ventilation Strategies
• Permissive hypercapnia: Accept higher PaCO₂ to avoid barotrauma4
• Prolonged expiratory time: Decrease RR, increase I:E ratio to 1:3 or 1:4
• Avoid high peak pressures: Use pressure-control if needed, minimize auto-PEEP
• Manual ventilation: Gives better "feel" for airway resistance and allows slower rates
⚠️ Prevention & Risk Factors
• High-risk patients: Asthma, COPD, smokers, recent URI, reactive airway disease
• Preoperative optimization: Optimize asthma control, consider preop bronchodilators
• Avoid triggers: Deep extubation, avoid histamine-releasing drugs (morphine, atracurium), minimize airway instrumentation
• LMA vs ETT: Consider LMA for low-risk surgery to reduce airway stimulation1
1 Woods BD, Sladen RN. Perioperative considerations for the patient with asthma and bronchospasm. Br J Anaesth. 2009;103 Suppl 1:i57-65. PMID: 20007991
2 Mitsuhata H, et al. Mechanisms and management of intraoperative bronchospasm. Curr Opin Anaesthesiol. 1996;9(3):238-242.
3 Rodrigo GJ, et al. Acute asthma in adults: a review. Chest. 2004;125(3):1081-1102. PMID: 15006973
4 Scalese MJ, et al. Severe Refractory Status Asthmaticus: A Review. J Intensive Care Med. 2020;35(10):977-988. PMID: 30987529

Airway Fire 3 refs

Combustion in airway from heat source + oxygen-enriched environment + flammable material

Immediate Call Help

Immediate Actions (Remember: STOP-DROP-ROLL)

  1. STOP gas flow: Immediately disconnect O₂ source and stop ventilation1
  2. DROP the ETT: Remove burning endotracheal tube from airway1
  3. ROLL patient to side: Pour saline into airway and oropharynx to extinguish fire1
  4. Mask ventilate with air or 21% O₂: Resume ventilation with lowest FiO₂ possible2
  5. Reintubate: Use new ETT (smaller size if edema present), assess damage with laryngoscopy/bronchoscopy1

Secondary Assessment & Management

  1. Bronchoscopy: Assess airway injury severity (mucosal burns, soot, debris)2
  2. Saline lavage: Irrigate airway to remove debris and carbonized material2
  3. Steroids: Consider dexamethasone 0.5 mg/kg IV (controversial, may reduce edema)2
  4. ICU admission: Monitor for delayed airway edema (peaks 12-24h), ARDS, pneumonia3
  5. No extubation: Keep intubated until edema resolves (typically 3-7 days)3
💊 Post-Fire Management
Dexamethasone (controversial): 0.5 mg/kg IV (may reduce edema)
Bronchodilators: Albuterol if bronchospasm develops
Antibiotics: NOT routinely indicated (no benefit for prophylaxis)
Ventilation strategy: Lung-protective ventilation, lowest FiO₂ maintaining SpO₂ >90%
⚠️ Fire Triangle (All 3 Required for Fire)
1. Oxidizer: O₂ (>21%), N₂O
2. Fuel: ETT, surgical drapes, gauze, alcohol prep solutions
3. Ignition source: Electrocautery, laser, fiberoptic light

Break one element to prevent fire - Lower FiO₂ to ≤30% during cautery near airway, use laser-safe ETT, keep flammables wet1
🔍 High-Risk Procedures
• Head & neck surgery: Laser laryngoscopy, tonsillectomy, tracheostomy
• Oral/facial surgery: Cautery near airway
• ENT procedures: Any procedure with electrocautery + high FiO₂
• Prevention: Use lowest safe FiO₂ (≤30%), laser-resistant ETTs, wet sponges around surgical field, pause O₂ during cautery1
⚠️ Post-Fire Complications
• Acute: Airway edema (delayed, peaks 12-24h), ARDS, pneumonia
• Delayed: Tracheal stenosis, granulation tissue formation
• Monitoring: Serial bronchoscopies, prolonged intubation (3-7 days typical)
• Tracheostomy: May be needed if severe injury or prolonged intubation anticipated3
1 ASA Task Force on Operating Room Fires. Practice Advisory for the Prevention and Management of Operating Room Fires. Anesthesiology. 2013;118(2):271-290. PMID: 23287706
2 Pruitt BA, Cioffi WG. Management of burns in the airway and face. Clin Plast Surg. 2009;36(4):555-567. PMID: 19793552
3 Worley SL. Fire safety in the operating room. AORN J. 2012;95(5):606-618. PMID: 22541771