Complications of Anesthesia

1. Introduction

• Complications of anesthesia are inevitable, even among experienced anesthesiologists.

• These range from minor issues (e.g., sore throat) to severe complications (e.g., cardiac arrest).

• The document categorizes complications into:

  • Intraoperative complications (occurring during surgery).

  • Postoperative complications (developing after surgery).

2. Intraoperative Complications

A. Laryngoscopy-Related Complications

• Trauma to teeth, tongue, tonsillar pillars, epiglottis, and vocal cords.

B. Endotracheal Tube (ETT) Complications

• Injury to vocal cords or trachea during intubation.

• Blockage due to secretions, blood clot, or foreign body.

• Bronchospasm, leading to difficulty in ventilation.

C. Complications During Induction

• Hypotension or hypertension from anesthetic agents.

• Arrhythmias (bradycardia, tachycardia, supraventricular tachycardia, cardiac arrest).

• Hypoventilation and upper airway obstruction.

• Histamine release → bronchospasm or anaphylaxis.

• Aspiration risk → Mendelson’s Syndrome (gastric content aspiration).

D. Complications During Maintenance

• Hypothermia or hyperthermia (Malignant Hyperthermia?).

• Electrolyte imbalances (hypoglycemia/hyperglycemia).

• Fluid overload or deficit → affects cardiovascular stability.

• Blood loss, leading to anemia.

• Mechanical issues → accidental kinking/disconnection of ETT or circuit.

• Thyroid crisis (hyperthyroidism/hypothyroidism).

• Coronary ischemia, heart failure, or myocardial infarction (MI).

• Embolism: Fat, air, or amniotic embolism.

3. Postoperative Complications

A. Airway & Respiratory Issues

• Persistent apnea due to residual muscle relaxants or dual blockade (e.g., scoline).

• Post-extubation laryngospasm or bronchospasm.

• Hypoxia and hypercarbia, leading to delayed recovery.

• Aspiration risk continues postoperatively.

• Atelectasis, cough, and tracheitis may develop.

• Tracheal stenosis (long-term complication of intubation).

B. Neurological & Cognitive Issues

• Postoperative confusion and cognitive decline (common in elderly patients).

• Delayed recovery → prolonged sedation effects.

• Awareness under anesthesia (psychological trauma or PTSD).

C. Temperature & Metabolic Issues

• Hypothermia → causes shivering, discomfort, and delayed drug metabolism.

• Halothane-induced hepatitis (rare but serious complication).

D. Miscellaneous

• Sore throat from intubation.

• Nausea and vomiting (PONV occurs in 20-30% of patients).

• Muscle pain from suxamethonium-induced fasciculations.

• Hoarseness of voice due to vocal cord trauma.

4. Complications Related to Patient Positioning

• Nerve Injury: Regional anesthesia & GA abolish protective reflexes, increasing risk of:

  • Peroneal nerve injury → foot drop.

  • Ulnar/radial nerve injury → hand weakness.

  • Brachial plexus injury → arm paralysis.

• Compartment syndrome → Associated with lithotomy position.

• Retinal ischemia → Prone or sitting position.

• Corneal abrasion → Can occur in any position but common in prone cases.

• Pressure sores/skin necrosis → Due to prolonged immobility.

5. Human Errors in Anesthesia Management

• Breathing circuit disconnection → leads to hypoxia.

• Mistaken drug administration → leads to severe adverse effects.

• Airway mismanagement → failure to secure ventilation.

• Anesthesia machine misuse or malfunction.

• Intravenous line disconnection → affects fluid management and drug delivery.

6. Complications of Neuroaxial (Spinal/Epidural) Block

• Hypotension & bradycardia → sympathetic blockade effects.

• Sensitivity to sedative medications → altered consciousness.

• Nausea & vomiting → linked to hypotension.

• Postdural puncture headache due to CSF leakage.

• Back pain & paresthesia (nerve irritation).

• Nerve injury, cauda equina syndrome, or total spinal anesthesia (rare but serious).

• Meningitis (infection risk from improper sterile technique).

• Spinal hematoma or abscess formation in high-risk patients.

7. Complications of Regional Anesthesia

A. Systemic CNS Toxicity

• Symptoms include headache, tinnitus, perioral numbness, confusion, seizures, apnea.

• Severe toxicity can cause LOC and respiratory depression.

B. Cardiovascular Toxicity

• Hypertension, tachycardia, then sudden hypotension.

• Arrhythmias (bradycardia, cardiac arrest).