Laryngiospasm A complication of General Anesthesia

1. Ahmad Ullah
Anesthesia Technologist
(KMU-IPMS)

2.  Involuntary and forceful contraction of
laryngeal muscles, which results from the
depolarization of superior laryngeal nerve.
(vocal cords adduction)
 Laryngospasm is the sudden and sustained
closure of the glottis, usually as a protective
mechanism to prevent aspiration, against a
noxious stimulus.
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3. Presentation
 • Difficult or impossible face mask
ventilation
 • Difficult or impossible ventilation with a
supraglottic airway
 • “Crowing” sound on inspiration
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4.  Rare but Mostly seen during anesthesia
Emergence 48%,
induction 28%,
maintenance 24%
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5.  Mechanical and chemical stimulation of
airway structures leading to afferent
stimulation of vagus and trigeminal nerve –
activation of intrinsic adductor muscles.
 It is mediated by the vagus nerve; this reflex
is designed to prevent foreign materials from
entering the tracheobronchial tree.
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6.  The intrinsic laryngeal muscles are the main
mediators of laryngospasm.
 These include the cricothyroid, lateral
cricoarytenoids, and the thyroarytenoid
muscles.
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7.  Unknown ....(43%)
 Patient-related
 – Young age
 – Anxiety
 – GERD
 – URI or active asthma (2~10 folds the risk)
 – Chronic smoker
 – Airway anomaly ,sleep apnea synd.
 – Unsupervised patients in recovery of
anaesthesia (specially children's)
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8.  – Throat and/or Airway surgery
 – Laryngeal Surgery
 – Thyroid surgery
 Tonsil's surgery
 SLN injury
 – Esophageal procedure
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9.  – Insufficient depth of anesthesia during
induction or surgical stimulus
 – i.v. induction agents
 • Barbiturate
 • Ketamine, saliva
 – LMA > ETT > face mask
 – Airway irritation
 Irritant Volatile anesthetics: isoflurane
 Mucus or blood after extubation
 Residual paralysis: common cause vomiting
or regurgitation
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10.  Harsh breathing inspiratory sound (stridor)
 exclude other causes of airway obstruction,
e.g.
 tongue drop, bronchospasm,
 – fall in spo2(usually fast)
 Partial laryngospasm
 • Signs of inspiratory airway obstruction
 – Use of accessory muscles
 – Paradoxical movement of chest and
abdomen
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11.  Auscultation : Inspiratory Obstruction
 Complete laryngospasm :
 absence of breath sounds
 Late change
 – Bradycardia
 – Cyanosis
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12.  • Identify patients at risk is the most
important
 • Nonirritant inhalational anesthetic, e.g.
 sevoflurane
 • Deep anesthesia before intubation
 No surgical stimulation in light plan of
anesthesia
 • Extubate while the lungs are inflated by
positive pressure
 – ⇓ Adductor response of laryngeal muscle
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13.  Drugs
 – Premedication with oral BZD
 – Anticholinergics ⇓ secretion
 – Lignocaine Spray to larynx at 4 mg/kg (1 mL
10% lidocaine for a 25 kg pt)
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14.  • Controversial in preventing laryngospasm
 Some said i.v. at 1 mg/kg 5 min before
extubation fairly effective as topical use
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15.  – Identify and remove the stimulus
 – Apply jaw thrust maneuver
 – Insert oral or nasal airway
 – Positive pressure ventilation with 100% O2
 – Anxiolysis( assurance and sedation)
 – Inj. Xylocaine 1 mg/kg
 – Inj. Propofol 0.25-1 mg /kg
 – Steroids -Inj. Hydrocortisone ,
Dexamethasone
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16.  – Call for help
 – Deepen the anesthesia level
 • If laryngospasm occurs without i.v. line
 intraosseous route offer a faster central
 circulation than peripheral
 • Lidocaine
 – SLN block
 – 5 mL of 2% lidocaine + 5 mL NS nebulized by
100% O2
 – Transtracheal injection of 1~2 mL 4%
lidocaine
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17.  Intravenous: atropine and succinylcholine
 Intramuscular : succinylcholine (4mg/kg)
 vocal cords relax within one minute; last
several minutes ….IPPV---Intubation
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19.  • Untreated laryngospasm can rapidly lead to
hypoxemia and hypercarbia.
 • Patients who generate high negative
inspiratory pressures while attempting to
breathe against the obstruction may develop
negative-pressure pulmonary edema.
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