Incidence of Acute Laryngeal Injury Following Endotracheal Intubation

In the United States, 55 000 patients receive care in more than 6 000 intensive care units (ICUs) each day. The most common reason for ICU admission is respiratory failure and the need for a mechanical ventilator. Although 50% to 70% of patients survive their acute illness, the remainder are left with massive impairments in health and overall functioning. One of the most severe post-ICU complications is airway scaring directly resulting from endotracheal intubation.

Scarring of the vocal cords or trachea after intubation results from mucosal injury by an endotracheal tube (i.e. breathing tube). The initial mucosal injury ultimately heals with pathologic fibrotic contracture. This fibrosis physiologically restricts ventilation, and produces life-threatening dyspnea and airway obstruction. Acute and chronic airway injury following intubation is largely unappreciated owing to the fact that the long-term sequelae of intensive respiratory support is rarely managed by practitioners providing acute care. Treatments for chronic airway injury are suboptimal. They are largely surgical and offer marginal improvement in breathing while causing permanently worsened voice. Preventative efforts to preserve laryngeal and tracheal function (through identification of modifiable risk factors) could reduce the incidence of this devastating complication of medical care. Additionally, early identification of acute laryngeal injury after intubation may prevent the development of chronic complications. Patients with acute post-intubation airway injury treated with early endoscopic surgery require significantly fewer procedures, and may avoid an invasive open surgical reconstruction compared with patients treated with chronic fibrotic scars.

The development of airway fibrosis and ventilatory obstruction has been linked to inflammatory processes. Macrolide antibiotics such as azithromycin has been shown to reduce mucosal airway inflammation. IN addition the combination of a macrolide antibiotic and budesonide an inhaled corticosteroid has been shown to work synergistically to reduce inflammation and modify the disease process of tracheal stenosis in rabbit models.

The purpose of this investigation is to delineate the incidence of acute and chronic laryngeal injury following intubation within our health system. In addition, this study seeks to identify risk factors for airway injury that may provide information to help reduce the incidence of injury or increase the speed of diagnosis through hospital based process measures. Finally, in patients with acute laryngeal injury, this study seeks to investigate the effects of azithromycin and budesonide to improve objective and subjective breathing measures in patients with Acute Laryngeal injury (ALgI) following endotracheal intubation.

Overview: Patients will be recruited from adult patients in the surgical and medical intensive care units of Vanderbilt Medical Center who were intubated for greater than 48 hours. Following informed consent and study enrolment, data will be stored in a secure REDCap database housed within a server located behind the Vanderbilt University Medical Center (VUMC) firewall. Data analysis will be performed by KSP at VUMC.

Protocol: Within 72 hours of extubation, ICU patients will be approached for participation by study KSP (they will be clinically evaluated for the ability to provide informed consent). If they are not able to consent for themselves an LAR will be approached for consent by study KSP. Consent will be electronic, paper, or via phone.

Consented and enrolled patients will undergo routine medical examination of their larynx with flexible nasolaryngoscopy after anesthetizing and decongesting the nose with 1% lidocaine mixed in oxymetazoline. During the examination, patients will be asked to sniff (which triggers opening of the vocal cords), and say "Eee" which (triggers closing). These maneuvers allow assessment of vocal fold movement. The evaluation will be recorded for subsequent blinded review. Recordings will be coded with a research identifier and stored digitally securely on a harddisk locked within the principle investigators office. If acute laryngeal injury is noted on examination, a repeat office-based examination of the larynx will be scheduled in 8 to 12 weeks.

The second phase of this study will investigate the effects of azithromycin and budesonide to improve objective and subjective breathing measures in patients with Acute Laryngeal injury (ALgI) following endotracheal intubation. The consenting process for these patients will mirror the first phase. In patients with ALgI, patients will be randomized to a medical therapy group consisting azithromycin 250mg or budesonide of 0.5mg for 14 days or non-drug placebo group. This study will be double blinded. For participants, a repeat examination will be scheduled at 12 weeks and at that time patients will be asked to complete surveys (CCQ, VHI-10, SF-12).

Consented patients will also have information abstracted from their medical record. Pertinent information collected will include patient-specific covariates; i.e. medical co-morbidities, laboratory values, and demographics as well as procedure-specific covariates; i.e. endotracheal tube size, length of intubation, recorded endotracheal tube cuff pressures, and the number of recorded intubation attempts. The initial and follow up examinations will be non-billable and provided no-cost to the patients. If chronic laryngeal injury is noted on follow-up examination, the patients will then be referred within the institution as a routine patient and offered standard treatment options as directed by a fellowship trained laryngologist.