NEET MDS Lessons
Anaesthesia
Emergency Drugs for Sedated Patients (AAPD Guidelines)
In the context of pediatric dentistry and sedation, it is crucial to be prepared for potential emergencies that may arise during or after sedation. The following is a list of emergency drugs that may be needed to rescue a sedated patient, along with their indications and uses.
Emergency Drugs
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Albuterol for Inhalation
- Indication: Bronchospasm or asthma exacerbation.
- Use: Administered via nebulizer or metered-dose inhaler to relieve bronchospasm.
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Ammonia Spirits
- Indication: Syncope or fainting.
- Use: Inhaled to stimulate respiration and increase alertness.
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Atropine
- Indication: Bradycardia or asystole.
- Use: Increases heart rate by blocking vagal effects on the heart.
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Diazepam
- Indication: Seizures or severe anxiety.
- Use: Administered intravenously or intramuscularly for rapid sedation or seizure control.
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Diphenhydramine
- Indication: Allergic reactions or anaphylaxis.
- Use: Antihistamine for allergic symptoms; may also be used for sedation.
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Epinephrine (1:1,000 and 1:10,000)
- Indication: Anaphylaxis or severe asthma attack.
- Use: 1:1,000 for intramuscular injection; 1:10,000 for intravenous administration in cardiac arrest.
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Flumazenil
- Indication: Benzodiazepine overdose.
- Use: Reversal agent for sedation caused by benzodiazepines.
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Fosphenytoin
- Indication: Status epilepticus.
- Use: Anticonvulsant for seizure control, administered intravenously.
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Glucose (25% or 50%)
- Indication: Hypoglycemia.
- Use: Administered intravenously to rapidly increase blood glucose levels.
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Lidocaine
- Indication: Cardiac arrhythmias or local anesthesia.
- Use: Antiarrhythmic agent for ventricular arrhythmias; also used for local anesthesia.
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Lorazepam
- Indication: Anxiety or seizures.
- Use: Sedative and anticonvulsant, administered intravenously or intramuscularly.
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Methylprednisolone
- Indication: Severe allergic reactions or inflammation.
- Use: Corticosteroid for reducing inflammation and managing allergic reactions.
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Naloxone
- Indication: Opioid overdose.
- Use: Opioid antagonist to reverse respiratory depression and sedation caused by opioids.
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Oxygen
- Indication: Hypoxia or respiratory distress.
- Use: Administered to improve oxygen saturation and support respiratory function.
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Racemic Epinephrine
- Indication: Croup or severe bronchospasm.
- Use: Administered via nebulization to reduce airway swelling and improve breathing.
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Rocuronium
- Indication: Neuromuscular blockade for intubation.
- Use: Non-depolarizing neuromuscular blocker for facilitating intubation.
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Sodium Bicarbonate
- Indication: Metabolic acidosis or hyperkalemia.
- Use: Administered intravenously to correct acidosis and manage elevated potassium levels.
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Succinylcholine
- Indication: Rapid sequence intubation.
- Use: Depolarizing neuromuscular blocker for quick intubation.
- Nitrous Oxide Cylinder: Blue
- “Tare Weight”: Gas cylinder apparatus
- Commonest post-intubation issue: Sore throat
- Blind nasal intubation: TMJ ankylosis
- Contraindications: Laryngeal edema (both oral & nasal)
- Confirmation: Capnography
- Aspiration prevention (gold standard): Tracheostomy
- Oral route in children preferred (avoid bleeding from adenoids)
- Sterilization of ET tube: ETO gas
Stages of General Anesthesia
| Stage | Name | Key Features |
|---|---|---|
| I | Analgesia / Disorientation | Begins with administration of anesthetic. Patient remains conscious but feels reduced pain. Ends with loss of consciousness. |
| II | Excitement / Delirium | Loss of consciousness with irregular breathing, involuntary movements, and possible vocalization. Reflexes may be hyperactive. |
| III | Surgical Anesthesia | Ideal stage for surgery. Regular respiration, muscle relaxation, and loss of reflexes. Divided into 4 planes based on depth. |
| IV | Medullary Paralysis | Dangerous stage. Severe depression of vital centers—respiratory and cardiovascular collapse. Requires immediate intervention. |
Clinical Notes
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Stage I is often brief due to rapid induction agents.
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Stage II is avoided or minimized with modern anesthetics to reduce risk of complications like laryngospasm.
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Stage III is carefully maintained during surgery.
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Stage IV is considered an overdose and must be prevented.
- Stage III Plane 3 → Surgical anaesthesia
- Most reliable indicator: Regular respiration
- Contraindicated in: Jaundice, Pheochromocytoma, Obstetric cases.
- Not contraindicated in: Previous Hepatitis A.
- Associated complications:
- Malignant Hyperthermia
- Hepatotoxicity
- ↑ Intracranial Tension
- Predisposes to Arrhythmias
- Stored: Amber bottles, colorless liquid.
- Preservative: Thymol
- Poor analgesic.
- Beta-blocker–like myocardial effects.
- Rapid, smooth induction.
- Dissolves in rubber.
| Agent | Property |
|---|---|
| Halothane | Most potent, second gas effect |
| Nitrous Oxide | Fast induction, highest MAC, least potent, diffusion hypoxia |
| Non-metabolized, bone marrow depression, not safe in ear surgery |
- Ether → Basis of anaesthesia staging
- MAC (Minimal Alveolar Concentration) → Indicator of potency
- Minimum O₂ in mix → 25%
- Agents fluorinated → 🔥 Non-inflammable
- Benzodiazepines:
- Produce anterograde amnesia
- Act on α-subunit of GABA-A receptors
- Muscle relaxation with Midazolam
- Flumazenil: Specific antagonist
- Lorazepam: Difficult reversal
| Feature | Detail |
|---|---|
| First affected muscle | Laryngeal |
| First to recover | Laryngeal |
| Site of action | Myoneural junction |
| d-Tubocurarine | Non-depolarizing, max histamine release |
| Reversal (Tubocurarine) | Neostigmine |
| Atracurium | Can cause convulsions, histamine |
| Hofmann degradation | Atracurium |
| Cisatracurium | Preferred (no histamine release) |
| Laudanosine (metabolite) | From Atracurium |