Anesthetic Emergencies

Of course, this is a critical topic yet teaching our future physicians and anesthesiologists to anticipate, recognize, and manage anesthetic emergencies is paramount to patient safety.

Here is a structured list of anesthesia emergencies. We have organized them by the physiological system or phase of care, which is a logical way to teach them.

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Anesthesia Emergencies: A Curriculum for Trainees

Introduction:
The management of perioperative emergencies is one of the most important topics during anesthesia training. Our primary role is to keep patients safe while they are at their most vulnerable. This requires a deep understanding of physiology, pharmacology, and, crucially, the ability to act decisively under pressure. We will not just memorize lists; we will build a framework for thinking critically and acting systematically when seconds count."

Category 1: Airway Emergencies

These are often the most immediate and dangerous crises. Failure to secure or maintain an airway can lead to hypoxic brain injury or death within minutes.

1. Can't Intubate, Can't Oxygenate (CICO):
   • Description: The ultimate airway emergency. Failure to secure the trachea with an endotracheal tube combined with an inability to maintain oxygenation via bag-mask ventilation or supraglottic airway.
   • Key Teaching Points: Immediate declaration of emergency. Follow the Difficult Airway Algorithm (DAA). The definitive rescue is Front of Neck Access (FONA)—e.g., cricothyrotomy. Hesitation is the enemy.
2. Unanticipated Difficult Airway:
   • Description: Encountering unexpected difficulty with laryngoscopy or ventilation after induction of anesthesia.
   • Key Teaching Points: Emphasize the ASA Difficult Airway Algorithm. The importance of calling for help early, limiting attempts, and moving to Plan B (LMA) and then Plan C (awaken vs. FONA).
3. Laryngospasm:
   • Description: A reflex glottic closure, often due to stimulation (e.g., secretions, blood, light anesthesia) during light planes of anesthesia (emergence or induction).
   • Key Teaching Points: Treatment escalates quickly: 100% O2 with firm positive pressure, Larson's maneuver (pressure in the 'laryngospasm notch'), deepening anesthesia with propofol, and as a last resort, succinylcholine for relaxation.
4. Bronchospasm:
   • Description: Intense constriction of the bronchial smooth muscle, mimicking severe asthma. Can be caused by anaphylaxis, aspiration, or airway irritation in a reactive airway patient.
   • Key Teaching Points: DDx includes anaphylaxis, aspiration, endotracheal tube obstruction. Treatment: deepen anesthesia (volatile agents are excellent bronchodilators), beta-2 agonists (albuterol), and epinephrine for severe cases.
5. Aspiration of Gastric Contents:
   • Description: Inhalation of gastric material into the lungs. A risk during induction, emergence, or in cases of delayed gastric emptying.
   • Key Teaching Points: Rapid sequence induction (RSI) is the primary prevention. If it occurs: immediate suction, 100% FiO2, PEEP, bronchoscopy if needed, and supportive care. Do not "lavage" the lungs.

Category 2: Cardiovascular Emergencies

Hemodynamic stability is our constant intraoperative battle. These emergencies represent extreme failures of that stability.

1. Malignant Hyperthermia (MH):
   • Description: A life-threatening hypermetabolic skeletal muscle crisis triggered by volatile anesthetics and succinylcholine in genetically susceptible individuals.
   • Key Teaching Points: Classic Signs: ETCO2 ↑↑, tachycardia, rigidity, hyperthermia (a late sign). Treatment: 1. GET HELP. 2. STOP TRIGGERS. 3. DANTROLENE. (2.5 mg/kg IV, repeat as needed). 4. Supportive cooling.
2. Local Anesthetic Systemic Toxicity (LAST):
   • Description: Life-threatening toxicity from an accidental intravenous injection of a large dose of local anesthetic.
   • Key Teaching Points: Signs: CNS (metallic taste, seizures, coma) and Cardiovascular (myocardial depression, arrhythmias, collapse). Treatment: 1. STOP injection. 2. GET HELP. 3. LIPID EMULSION 20% (1.5 mL/kg bolus, 0.25 mL/kg/min infusion). 4. Avoid propofol if unstable; avoid vasopressin/CCBs early on.
3. Anaphylaxis:
   • Description: A severe, life-threatening, generalized hypersensitivity reaction. Common triggers: antibiotics (beta-lactams), muscle relaxants, chlorhexidine, latex.
   • Key Teaching Points: Signs: Bronchospasm, profound hypotension, tachycardia, rash, edema. Treatment: 1. STOP the trigger. 2. EPINEPHRINE (5-10 mcg IV boluses). 3. Fluids, 100% O2, bronchodilators, steroids/antihistamines are secondary.
4. Hemorrhagic / Hypovolemic Shock:
   • Description: Rapid and significant blood loss leading to circulatory collapse.
   • Key Teaching Points: This is a team sport. Communicate with the surgeon. Massive Transfusion Protocol (MTP). Goal is permissive hypotension and balanced resuscitation with PRBCs, FFP, platelets (1:1:1 ratio) to avoid coagulopathy and acidosis.
5. Cardiac Arrest (PEA/VT/VF/Asystole) under Anesthesia:
   • Description: The ultimate cardiovascular collapse.
   • Key Teaching Points: The H's and T's are your best friend! Hypovolemia, Hypoxia, Hydrogen ion (acidosis), Hyper/Hypokalemia, Hypothermia, Tamponade (cardiac), Tension pneumothorax, Toxins, Thrombosis (PE, MI). Tailor ACLS to the OR (e.g., early epinephrine, treat underlying cause).

Category 3: Equipment & System Failures

We must be masters of our machine. These are failures we must be able to diagnose instantly.

1. Hypoxic Gas Mixture:
   • Description: Delivery of a gas mixture with an insufficient FiO2 to the patient. Causes: empty O2 tank, wrong gas tank connected, malfunctioning mixer.
   • Key Teaching Points: Always check your machine! Monitors are your last line of defense. Low O2 alarm and falling SpO2 are key signs. Immediate management: disconnect patient from circuit and ventilate with 100% O2 via a self-inflating resuscitation bag (Ambu bag).
2. Breathing Circuit Disconnect or Leak:
   • Description: A disconnection between the patient and the anesthesia machine.
   • Key Teaching Points: The apnea and low-pressure alarms will sound. Immediate check: "DOPE" - Disconnect, Obstruction, Pneumothorax, Equipment failure.
3. Total Intravenous Anesthesia (TIVA) Pump Failure:
   • Description: Pump occlusion, empty syringe, or battery failure leading to an unintended "light" anesthetic or awareness.
   • Key Teaching Points: Always have a secondary plan (e.g., a drawn-up syringe of propofol). Use end-tidal gas monitoring if available. Monitor for signs of light anesthesia (tachycardia, hypertension, movement).

Category 4: Metabolic & Other Emergencies

1. Hypoglycemia:
   • Description: Dangerous low blood glucose, especially in diabetics or patients on long-term steroids.
   • Key Teaching Points: Unexplained tachycardia, hypotension, or sweating in a diabetic patient should prompt a glucose check. Treat with IV dextrose.
2. Hyperkalemia:
   • Description: Life-threatening elevation in serum potassium. Can be caused by succinylcholine, massive transfusion, reperfusion injury, or renal failure.
   • Key Teaching Points: Signs: peaked T-waves, widened QRS, bradycardia, sine wave, asystole. Treatment: Calcium chloride (stabilizes myocardium), insulin+glucose, albuterol, bicarbonate, dialysis.
3. Thyroid Storm:
   • Description: A rare but catastrophic hypermetabolic state in undiagnosed or poorly controlled hyperthyroidism, often precipitated by the stress of surgery.
   • Key Teaching Points: Signs: Hyperthermia, tachycardia out of proportion to fever, agitation, delirium. Treatment: Supportive care, beta-blockers (esmolol), antithyroid drugs (PTU), steroids.

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Conclusion:

"Mastering these emergencies is not about memorizing steps. It is about building a mental framework and understanding physiology so well that when a system fails, you know how to support it. It is about practicing drills so that your hands know what to do when your mind is under stress. And most importantly, it is about knowing that your first action in any crisis is always the same: Call for help. You are never alone in this.