title: Age and comorbidity as risk factors for vocal cord paralysis associated with tracheal intubation.
abstract: BACKGROUND
  Vocal cord paralysis after tracheal intubation may be attributed to ageing and comorbidity. However, the relationship between patient characteristics and the risk of vocal cord paralysis is unknown.
  
  
  METHODS
  We prospectively analysed data representing 31 241 consecutive surgery patients who underwent tracheal intubation to determine whether duration of intubation, age, sex, and cardiovascular, cerebrovascular, and metabolic diseases were risk factors for vocal cord paralysis associated with intubation. Patients with vocal cord paralysis from any other causes were excluded.
  
  
  RESULTS
  Twenty-four (0.077%) suffered vocal cord paralysis (left, 16 patients; right, 8 patients). The risk was increased when intubation lasted 3-6 h (odds ratio, 2.0; 95% confidence interval, 1.1-5.6; P = 0.002) or 6 h or more (odds ratio, 14.5; 95% confidence interval, 5.2-40.9; P < 0.0001). The risk was increased in patients aged 50-69 (odds ratio, 3.6; 95% confidence interval, 1.2-11.1; P = 0.02) and 70 yr or above (odds ratio, 3.9; 95% confidence interval, 1.2-12.8; P = 0.02). The risk was increased with diabetes mellitus (odds ratio, 2.5; 95% confidence interval, 1.1-7.3; P = 0.03) and hypertension (odds ratio, 2.1; 95% confidence interval, 1.1-6.0; P = 0.03).
  
  
  CONCLUSIONS
  The risk of vocal cord paralysis was increased three-fold in patients aged 50 or above, two-fold in patients intubated 3-6 h, 15-fold in patients intubated 6 h or more, and two-fold in patients with a history of diabetes mellitus or hypertension. Our results are informative for informed consent, patient counselling, and intubation decision-making.
authors.affiliation: Department of Anaesthesiology and Intensive Care, Hamamatsu Medical Center, Hamamatsu, Japan. mkikura@hotmail.com
authors.forename: M
authors.initials: M
authors.lastname: Kikura
authors.forename: K
authors.initials: K
authors.lastname: Suzuki
authors.forename: T
authors.initials: T
authors.lastname: Itagaki
authors.forename: T
authors.initials: T
authors.lastname: Takada
authors.forename: S
authors.initials: S
authors.lastname: Sato
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D003920:Diabetes Mellitus / Q000453:epidemiology; D004812:Epidemiologic Methods; D005260:Female; D006801:Humans; D006973:Hypertension / Q000453:epidemiology; D007223:Infant; D007231:Infant, Newborn; D007442:Intubation, Intratracheal / Q000009:adverse effects* / Q000295:instrumentation / Q000379:methods; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000175:diagnosis / Q000453:epidemiology*; D012737:Sex Factors; D013997:Time Factors; D014826:Vocal Cord Paralysis / Q000175:diagnosis / Q000453:epidemiology / Q000209:etiology*