Risk factors for dysphagia in critically-ill patients with prolonged orotracheal intubation

Dysphagia after prolonged orotracheal intubation is reported to increases a patient's risk for aspiration, leading to increased risk for morbidity and mortality. Identification of specific risk factors that may predispose a patient to post-extubation dysphagia and aspiration risk is important. However, previous studies have not consistently identified concrete risk factors of post-extubation dysphagia in critically-ill patients. This two part study sought to identify specific risk factors for post-extubation dysphagia and increased aspiration risk in critically-ill patients. Study A retrospectively and Study B prospectively examined 70 medical and surgical ICU patients who endured mechanical ventilation for >/= 72 hours. Study A participants underwent either a Modified Barium Swallow Study (MBS) or Fiberoptic Endoscopic Evaluation of Swallowing (FEES) examination to objectively identify swallowing disorders. Two independent reviewers analyzed charts from a Speech Pathology database for post-extubation dysphagia. Study B participants underwent a FEES examination to objectively assess swallowing function. Two expert Speech-Language Pathologists (SLPs) that were blinded to the patient's medical diagnoses and purpose of the study conducted the FEES examinations and interpreted their outcomes. A third rater analyzed an additional 20 percent of randomly selected swallows. In both studies, participants were clustered into one of 7 admission diagnoses groups, and one of 5 reasons for intubation groups. Duration of intubation, gender, reintubation, Penetration Aspiration Scale (PAS outcomes) and 4 Point Dysphagia Severity Scale Ratings were analyzed. The results of Study A (retrospective) revealed that age and duration of intubation were independently associated with post-extubation dysphagia severity. The odds of a participant presenting with a more severe dysphagia was increased by 7.5% for each additional year of age (p= 0.009). The odds of a participant presenting with a more severe dysphagia severity rating was increased by 48.2% for each additional day of intubation (p=0.032). Age and duration of intubation were also independently associated with aspiration. The odds of a participant exhibiting aspiration was increased by 4.1% for each additional year of age (p=0.018). The odds of a participant exhibiting aspiration was increased by 25% for each additional day of intubation (p=0.004). Reintubation (0=0.008) was significantly associated with dysphagia severity. Pneumonia (p=0.034) was also significantly associated with increased aspiration risk. The Results of Study B (prospective) demonstrated that age was independently associated with post-extubation aspiration risk. The odds of a participant exhibiting aspiration was increased by 4.5% for each additional year of age (p=0.027). Admission diagnosis, particularly infectious, was significantly associated with aspiration (p=0.046). Excellent inter-rater reliability was demonstrated for 20% of patient's overall dysphagia severity ratings (r=0.918). In conclusion, age was independently significantly associated with increased post-extubation dysphagia severity and aspiration. Further investigation is warranted to examine the risk factors that were only found to be significant in one of the two studies, i.e. duration of intubation, presence of PNA, reintubation and admission diagnosis.