7/27/2019 Laryngospasm 20081223

1/22

Laryngospasm

R3

7/27/2019 Laryngospasm 20081223

2/22

Introduction A protective reflexive glottic closure

prevent aspiration

Its exaggeration impedes respiration

Self-limited mostly: prolonged hypoxia andhypercapnea abolish the reflex

If sustained, morbidity (e.g. cardiac arrest,

PE,etc.) and mortality ensue

7/27/2019 Laryngospasm 20081223

3/22

Epidemiology Inversely related with age

The overall incidence: 0.87%

7/27/2019 Laryngospasm 20081223

4/22

Anatomy

7/27/2019 Laryngospasm 20081223

5/22

Anatomy

7/27/2019 Laryngospasm 20081223

6/22

Physiology A multitude of mechanoreceptors,

chemoreceptors and thermoreceptors arethroughout the larynx

The density is greatest around the laryngeal

opening The posterior aspect of the true vocal folds has

greater density than the anterior

Stimulation of these receptors induce short-livedglottic adduction to protect from aspiration

7/27/2019 Laryngospasm 20081223

7/22

Mechanism Afferent fibers within the internal branch of the SLN

Spasmodic dysphonia: involuntary spasms in thelaryngeal muscles during speech production Neuroimaging(20:20) and postmortem histopathology(20:3)

Axonal and myelin content in the genu of internal capsule

Mineral depositions in parenchyma and vessel walls of the post.limb of the int. capsule, putamen, globus pallidus and cerebellum

Efferent response to the entire vagus apnea,bronchoconstriction, bradycardia, peripheral vasculartone change

There is a speculation: such a response leads to suddeninfant death, possibly in reaction to LPR

7/27/2019 Laryngospasm 20081223

8/22

Risk Factor Patient-related

Young age

Anxiety GERD URI or active asthma

2~10 folds the risk

Chronic smoker

Airway anomaly Surgery-related

T and/or A LMS Thyroid surgery

SLN injury Hypoparathyroidism

Esophageal procedure Distal afferent nerves

Anesthesia-related Insufficient depth of

anesthesia during induction i.v. induction agents

Barbiturate Ketamine saliva

LMA > ETT > face mask

Airway irritation Volatile anesthetics Mucus or blood after

extubation

Children supervised by lessexperienced anesthesiologist

7/27/2019 Laryngospasm 20081223

9/22

Prevention Identify patients at risk is the most important

Nonirritant inhalational anesthetic, e.g.sevoflurane Deep anesthesia before intubation Extubate while the lungs are inflated by positive

pressure Adductor response of laryngeal muscle Artificial cough

5% CO2 inhalation for 5 min before extubaionCO2 exhalation drive > the laryngospasmreflex Acupuncture

7/27/2019 Laryngospasm 20081223

10/22

Prevention Drugs

Premedication with oral BZD upperairway reflex during induction

Anticholinergics secretion

Lidocaine

Spray to larynx at 4 mg/kg (1 mL 10% lidocaine fora 25 kg pt)

30 min in duration

7/27/2019 Laryngospasm 20081223

11/22

Intravenous Lidocaine

Gilbert first used i.v. lidocaine as an

adjunct to general inhalation agents in1951

Controversial in preventing laryngospasm Some said i.v. at 1 mg/kg 5 min before

extubation fairly effective as topical use

7/27/2019 Laryngospasm 20081223

12/22

Deep versus Awake Extubation Controversial

Awake extubation

Protect the airway from aspiration

Deep extubation Less likely to cough and strain, which can

cause bleeding throat irrtation

7/27/2019 Laryngospasm 20081223

13/22

7/27/2019 Laryngospasm 20081223

14/22

Treatment Partial laryngospasm

Identify and remove the stimulus

Apply jaw thrust maneuver Insert oral or nasal airway Positive pressure ventilation with 100% O2

Complete laryngospasm

Call for help Deepen the anesthesia level

If laryngospasmoccurs without i.v. line intraosseousroute 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

7/27/2019 Laryngospasm 20081223

15/22

Superior Laryngeal Nerve Block

7/27/2019 Laryngospasm 20081223

16/22

The LaryngospasmNotch

7/27/2019 Laryngospasm 20081223

17/22

7/27/2019 Laryngospasm 20081223

18/22

Follow Up Assess for the possibility of developing

Pulmonary aspiration

Postobstructive negative pressure pulmonaryedema

7/27/2019 Laryngospasm 20081223

19/22

Paroxysmal Laryngospasm Extremely rare and is diagnosed by history:

spontaneous sudden onset of stridulousdyspnea, resolve within minutes

Frequently have a positional component, maywake the patient

Extremely distressing, impending doom

LPRmucosal hypersensitivitymaladaptedreflex arc

Aggressive elimination of LPR satisfactorilytreated the majority of patients

7/27/2019 Laryngospasm 20081223

20/22

7/27/2019 Laryngospasm 20081223

21/22

Reference Head & Neck Surgery - Otolaryngology, 4th Edition ABERRANT RECURRENT LARYNGEAL NERVE REINNERVATION AS A CAUSE

OF STRIDOR AND LARYNGOSPASM Ann Otol Rhinol Laryngol 113:2004

Aerosolized Lidocaine for Relief of Extubation LaryngospasmANESTH ANALG2005;101:1563

An approach to the management of paroxysmal laryngospasm The Journal ofLaryngology & Otology ( 2008), 122, 5760.

Focal white matter changes in spasmodic dysphonia: a combined diffusion tensorimaging and neuropathological study Brain (2008), 131, 447-459

Intervention steps for treating laryngospasmin pediatric patients PediatricAnesthesia 2008 18: 297302

Laryngospasm: review of different prevention and treatment modalities PediatricAnesthesia 2008 18: 281288

Laryngospasmin pediatric practice Pediatric Anesthesia 2008 18: 279280 Risk factors for laryngospasmin children during general anesthesia Pediatric

Anesthesia 2008 18: 289296 The use of preoperative lidocaine to prevent stridor and laryngospasmafter

tonsillectomy and adenoidectomy Otolaryngol Head Neck Surg 1998;118:880-2. Transtracheal lignocaine: effective treatment for postextubation stridor Anesth

Intensive Care 2007; 35:128-131

7/27/2019 Laryngospasm 20081223

22/22

Thank you for listening