1. STRIDOR
ANNE ASPIN 2010

2. Common causes Laryngomalacia – 60% Congenital subglottic stenosis
Vocal cord palsy - unilateral, birth trauma – temporary
Bilateral vocal cord palsy assoc other congenital anomalies

3. Morimoto et al (2004) 97 patients 1991-2001 Laryngomalacia 32%
Vocal cord palsy and laryngeal stenosis 22%, within 2/12, severe dyspnoea
Haemangioma or papilloma 11%
Cystic disease 7%

4. cont
2 / 31 of laryngomalacia and 2 / 22 VCP had neuromuscular disorders
3 of VCP complicated by laryngeal stenosis
33 / 97 Tracheostomy
Sometimes stridor is the only presenting symptom. Past history important

5. Investigation Rigid or direct microlaryngoscopy – general anaesthetic.
Flexible fibre- optic laryngoscope, neonate awake (first line choice now)

6. Case history 6/12 girl Fever, coughing Inspiratory stridor
Palpable neck swelling, bulging pharyngeal wall
Limited movement of neck
? spasmodic croup, lymphadenitis coli
Found to be retro pharyngeal abscess

7. Treatment
Oral incision
Drainage of abscess
Antibiotics

8. Unilateral vocal cord paralysis
Stridor
Laryngospasm
Dyspnoea
Cause by abnormal innervation of nerve branches into adductor fibers

9. Cases Post Thyroid surgery Post cervical disc surgery
After Herpes simplex virus with cranial nerve involvement
Fire optic laryngoscopy showed affected vocal cord immobile

10. Treatment
Laryngeal electromyography showed evidence of reduced but intact voluntary motor conduction in thyroarytenoid muscle.
Botox injections

11. Research
Objective
Determine stridor at rest after oral Prednisolone 1mg/kg
And whether quick response after mild croup

12. Method
Retrospective explicit chart review of children over 1 year of age admitted to a teaching hospital
Patient demographics
Croup scores at AE
Duration of stridor at rest after steroids

13. Results 188 cases analysed
Median duration at rest was 6.5 hrs, range 0.5 hrs- 82 hrs
Patients with low score at AE recovered quicker in response to steroids, early discharge home.

14. Amphotericin induced stridor
Adverse effects reported Amphotericin B
Dyspnoea
Tachypnoea
Bronchospasm
Haemoptysis
hypoxia

15. Objective
To review mechanism of action and reports of respiratory adverse effects for Amphotericin B, the liposomal preparations for Amphotericin B and the differential diagnosis of stridor
Medline search 1966 – 2002 looking for possible mechanisms and immunoregulatory effects of Ampho B

16. Results
Amphotericin B shows increase in tumour necrosis factor alpha (TNF alpha) concentrations in macrophages.
Induces prostaglandin E2 synthesis, increasing production of interleukin1 beta in mononuclear cells

17. Conclusion
Amphotericin B induces production of TNF alpha, interferon gamma and interleukin 1 beta which have toxic effects.

18. Medicines for children
Test dose infused over 30 mins – 100mcg
Renal impairment
Low serum pott, mag, phos
Lft’s
arrhythmias
Pulmonary reactions if Amph and leucocyte Tx.

19. References
Bent J (2006). Pediatric laryngotracheal obstruction : current perspectives on Stridor. The Laryngoscope. 116 (7) :
Berghout E, Peetsold M, Verboom A, Plotz F (2005). Inspiratory Stridor in a Child with a Retropharyngeal Abscess Instead of the Normally Expected Sublottic Laryngitis. Ned Tijdschr Geneeskd. 149(9): (Article in Dutch)
Kavshal M, Upadhyay A, Aggarwal R, Deorari A (2005). Congenital Stridor Due to Bilateral Vocal Cord Palsy. Indian Journal of Paediatrics. 72(5): 443-4
Lowery M, Greenberger P (2003) Amphotericin Induced Stridor: A Review of Stridor, Amphotericin Preparations, and their Immunoregulatory Effects. Annals of Allergy Asthma Immunology. 91(5): 460-6

20. References cont.
Majumdar S, Bateman N, Bull P (2006). Paediatric Stridor. Archives of Disease in Childhood, Education Practice Edition. 91 : ep101 - ep105.
doi /adc
Morimoto N, Kawashiro N, Tsuchihashi N, Taiji H (2004). Congenital Laryngeal Stridor. Nippon Jibinkoka Gakkai Kaiho. 107(7):690-4
Moumoulidis I, Gray R, Wilson T (2005). Outpatient Fibre-optic Laryngscopy for Stridor in Children and Infants. European Archives Otorhinolaryngology. 262(3): 204-7
Parker R, Powell C, Kelly A (2004). How Long Does Stridor At Rest Persist in Croup After The Administraton of Oral Prednisolone? Emergency Medicine. Vol 16, Iss 2, p135
Tewfik T, Sobol S (2010). Congenital malformations, larynx.
Woo P, Mangaro M (2004). Aberrant Recurrent Laryngeal Nerve Innervaton As A Cause of Stridor and Laryngospasm. Annals of Otology, Rhinology, Laryngology. 113(10): 805-8