Author: Lucy I-Ning Huang
Huang, Lucy I-Ning, 2020 The voice and laryngeal investigation standards post-extubation, Flinders University, College of Medicine and Public Health
Terms of Use: This electronic version is (or will be) made publicly available by Flinders University in accordance with its open access policy for student theses. Copyright in this thesis remains with the author. You may use this material for uses permitted under the Copyright Act 1968. If you are the owner of any included third party copyright material and/or you believe that any material has been made available without permission of the copyright owner please contact copyright@flinders.edu.au with the details.
Background
Laryngeal injury post prolonged intubation in the ICCU population is commonly thought to resolve spontaneously within a short period of time. However, there are some injuries that may persist to affect laryngeal function. These patients are not routinely assessed after prolonged intubation. This study aims to assess whether bedside voice assessments are able to identify laryngeal injuries for early referral to speech pathology or otolaryngology. The secondary aim is to assess the natural history of intubation-related laryngeal injuries prior to discharge from hospital. In order to answer these questions, the Flinders laryngeal injury score (FLIS) was developed to evaluate laryngeal injuries and severity.
Methods
Patients intubated for at least 24 hours and able to follow instructions after extubation were recruited. Those with head and neck injury, unable to phonate and conversion to tracheostomy were excluded. Patients were assessed at 24-48 hours and at 5-7 days after extubation using digital video nasoendoscopy (constant white light and stroboscopy) and voice assessments (s/z ratio, GRBAS and CAPE-V). Endoscopic findings were correlated with voice outcomes. Patient demographics and risk factors were also assessed for correlation with laryngeal and voice outcomes.
FLIS was developed in conjunction with two senior otolaryngologists after reviewing the literature of the common injuries secondary to intubation. It is a point-based scoring system which identifies and grades laryngeal pathology (oedema, erythema, ulceration, granuloma, stenosis and vocal fold mobility). The FLIS inter- and intra-rater reliability was assessed by 3 otolaryngology consultants, 3 otolaryngology trainees, 1 ICCU consultant and 1 speech pathologist after reviewing 20 videos of videolaryngoscopy in the ICCU population who have been intubated for at least 24 hours.
Results
60 patients participated in the study, and 37 patients completed both assessments. The median (IQR) duration of intubation was 60.1 (38.2-136.5) hours. The incidence of laryngeal injury was high (97% and 84% at 24 hours and 5 days post extubation). The most common injury identified was vocal process ulceration or granuloma. There were no statistical correlations between laryngeal examination findings and voice assessments.
The total FLIS score demonstrated moderate inter-rater reliability (ICC=0.59) with an intra-rater percentage agreement of 85% with all raters. When analysed separately, the consultant group had the best inter-rater reliability (ICC=0.91) and intra-rater percentage agreement of 91%. The trainee group also demonstrated good inter-rater reliability (ICC=0.81), with the remaining group scoring an ICC of 0.56.
Conclusion
Laryngeal injury and dysphonia are very common after prolonged intubation and the incidence remained high after 5 days. Bedside voice assessments were not able to determine the laryngeal injuries in this population. It is important to refer early to speech therapy and otolaryngology if these patients have persistent symptoms of dysphagia, dysphonia or dyspnoea after prolonged intubation. The FLIS demonstrated good inter-rater reliability amongst the otolaryngology consultant and trainee group. The FLIS is a simple system that may be used to quantify the severity of translaryngeal injury and to assess the recovery or response to therapy.
Keywords: larynx, intubation, injury, voice
Subject: Surgery thesis
Thesis type: Masters
Completed: 2020
School: College of Medicine and Public Health
Supervisor: Eng Ooi