Dr. S. Parthasarathy MD., DA., DNB, MD (Acu), Dip. Diab. DCA, Dip. Software statistics PhD (physio) Mahatma Gandhi medical college and research institute, puducherry, India Laryngospasm

Definition A protective reflexive glottic closure which prevents aspiration if exaggerated impedes respiration to produce morbidity and occasionally mortality.

Self-limited mostly: prolonged hypoxia and hypercapnia abolish the reflex.

Incidence 0.87 % - overall Children 0 -9 years – 1.74 % Infants – 2.82 % Most occurs during anesthesia – Emergence 48%, induction 28%, maintenance 24%

Two reasons Laryngospasm occurs during anesthesia for : a lack of inhibition of glottic reflexes because of inadequate central nervous system depression secondly increased stimuli

Pathophysiology Three levels Vocal cords – shutter Inspiratory pressure gradient increases Thyrohyoid shortens – (extrinsic) Supra glottic tissue,False vocal cords loosen to become a redundant tissue – ball Falls on the opening

Ball valve

Certain factors ??? – patient H/O URI 10 times – 6 weeks Wheezing Presence of Ryle s tube Smoking – passive - Smokers – 10 days GERD Down, parkinson, hypocalcemia, hypomagnesemia

Surgical factors Oral endoscopy Tonsillectomy Adenoidectomy Appendicectomy Hypospadias Skin graft in children Thyroid surgeries

Anaesthetic factors Rarely as transfusion reactions LMA > ETT Insufficient depth Ketamine – secretion Mucus and blood Desflurane

Clinical manifestations Partial – stridor Complete – laryngospasm – no air movement – tracheal tug, paradoxical breathing Oxygen desaturation 61% – Bradycardia 6% – Cardiac arrest 0.5% – Pulmonary aspiration 3% – Postobstructive negative pressure PE 4% Complications

Differential diagnosis: Bronchospasm Supraglottic obstruction Vocal cord palsy. Bilateral incomplete palsy is more dangerous than complete palsy. Tracheomalacia Psychogenic Laryngomalacia Airway edema Hematoma, soft tissue obstruction, foreign material such as throat packs.

Treatment Prevention

Identify patients at risk for laryngospasm (described already) Sevoflurane Deep extubation – no touch technique Positive pressure inflation of the lungs before tracheal extubation

Prevention Anticholinergics Benzodiazepines IV lignocaine IV magsulf Use 5% carbon dioxide (CO2)( for 5 min prior to tracheal extubation) Extubate deep / no touch technique Partially inflated LMA

the “no touch” technique blood and secretions are carefully suctioned from the pharynx, - extubate patient is then turned to the lateral (recovery) position the volatile anesthetics are discontinued, and no further stimulation is allowed until patients spontaneously wake up.

Treatment

Seek help Laryngoscopy Remove secretions, mucus, blood 100 % oxygen – CPAP LARSON maneuver Subhypnotic propofol -0.2 mg/kg Scoline – 0.1 – 1 mg / kg Atropine

Jaw thrust

Larson Maneuver -- Laryngospasm notch

Three problems with scoline Scoline apnea Previous non depolarizers Hyperkalemia No IV access – Scoline 4 mg / kg IM Intra osseous route – described

Chest compression Half the force of CPR / min. extended palm of the free hand placed on the middle of the chest, with the fingers directed caudally. Partial ok Complete – it can convert to partial

Other options Doxapram – 1.5 mg / Kg for 15 seconds IV nitroglycerin 4 mcg /kg Superior laryngeal nerve block

Algorithms

Summary Definition Incidence Factors Pathophysiology Signs Prevention Treatment

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