title: Role of estimation of arterial blood gases in the management of stridor.
abstract: OBJECTIVE
  We studied the epidemiology and etiology of stridor in our patients along with the role of arterial blood gas (ABG) analysis in their management. We also reviewed their prognostic indices and the clinical outcomes.
  
  
  METHODS
  It was a prospective study in a tertiary referral hospital in which 72 patients presenting with stridor, were independently evaluated by 3 different clinicians and clinically classified into mild, moderate and severe. Based on ABG values (pH, PO2, PCO2), we defined 3 groups of patients viz, those in respiratory failure, impending respiratory failure and those with no evidence of failure. Treatment was directed at the cause of stridor. Clinical outcomes were assessed and results classified as resolved, improved, stable and death.
  
  
  RESULTS
  Out of 72 patients, kappa coefficient of agreement between the 3 observers were found to be 0.014, indicating poor interobserver reliability for the working clinical classification. However, ABG analysis indicated otherwise, with 6 patients in respiratory failure, 19 progressing to impending failure. Hence we complied by the more objective ABG analysis in planning management. Laryngomalacia in children and hypopharyngeal malignancies in adults were found to be the most common causes of stridor in our study. As compared to other conditions, laryngomalacia in children had a poorer outcome (p = 0.001).
  
  
  CONCLUSIONS
  Early detection of impending respiratory failure was instrumental in achieving better clinical outcomes in our patients presenting with stridor. Thus we inferred that ABG analysis is a valuable tool in the effective management of stridor.
authors.affiliation: Department of Otorhinolaryngology, Kasturba Medical College, Mangalore, India.
authors.forename: M
authors.initials: M
authors.lastname: Panduranga Kamath
authors.forename: Mahesh Chandra
authors.initials: MC
authors.lastname: Hegde
authors.forename: Suja
authors.initials: S
authors.lastname: Sreedharan
authors.forename: Kiran
authors.initials: K
authors.lastname: Bhojwani
authors.forename: Vandana
authors.initials: V
authors.lastname: Vamadevan
authors.forename: K V
authors.initials: KV
authors.lastname: Vishwas
keywords: Blood gas analysis; Endotracheal intubation; Respiratory failure; Stridor; Tracheostomy