Laryngopharyngeal Reflux
- Article Author:
- Jens Brown
- Article Editor:
- Carl Shermetaro
- Updated:
- 4/22/2020 10:04:40 AM
- For CME on this topic:
- Laryngopharyngeal Reflux CME
- PubMed Link:
- Laryngopharyngeal Reflux
Introduction
The term laryngopharyngeal reflux (LPR) describes the anatomical location of the disease as well as its cause. According to Sataloff, “laryngopharyngeal reflux incorporates a complex spectrum of abnormalities.” [1] The airway is subdivided anatomically beginning with the oropharynx, then the hypopharynx, supraglottis, glottis, subglottis, and finally, the trachea. The area of concern, and what brings most patients into the clinic, is the effect of reflux on vocal cords or glossitis. Reflux is normally sequestered within the stomach and sometimes escapes into the distal esophagus, which has been described in other literature.
In healthy individuals, there are four barriers to reflux encroaching on the larynx: the lower esophageal sphincter, upper esophageal sphincter, esophageal peristalsis, and epithelial resistance factors. Dysfunction in any of the above will lead to symptoms of laryngopharyngeal reflux.
The upper esophageal sphincter is the final gatekeeper in antireflux. The area of the distal pharynx and proximal esophageal sphincter only opens for specific physiologic demands, such as swallowing under tonic contraction. This is made up of the cricopharyngeus, thyropharyngeus, and the proximal cervical esophagus muscles, forming a c-shaped sling that attaches to the cricoid cartilage. The tonic pressure induced by these muscles can be decreased with general anesthesia, sleep state, and cigarette consumption.
The lower esophageal sphincter is located at the gastroesophageal junction whose contracture leads to circular closure and prevention of egress of stomach acid. The diaphragmatic crura make up this critical antireflux mechanism.
The esophagus, with the help of gravity and peristalsis, can clear the acid that makes its way more proximal than expected. A mucus layer is present along the esophagus that is a barrier to large molecules, such as pepsin, but does not help prevent acid penetration. Also present is the aqueous layer, which helps form a protective alkaline buffer.
Etiology
Direct mucosal damage from acidic exposure, typically found in the esophagus, damages the laryngeal epithelium. Ciliary flow is impeded at pH 5.0 and completely halted at pH 2.0. With decreased ciliary flow, there is a decrease in resistance to infection as well.
Epidemiology
It is believed that 10% of patients visiting otolaryngology clinics have symptoms attributed to laryngopharyngeal reflux, and 55% of patients with hoarseness have laryngopharyngeal reflux impacting the quality of their voice.[2]
Pathophysiology
The retrograde flow of gastric acid and pepsin induces laryngeal mucosal damage and impaired mucociliary clearance. Three different theories explain this damage. 1) Direct contact of acid and pepsin with the epithelium induces damage. 2) Gastric refluxate with additional vocal abuse causes symptoms. 3) Mucosal lesions.[3] The esophageal-bronchial reflex theory suggests that acid in the distal esophagus vagally stimulates a chronic cough, which induces laryngeal symptoms.
Histopathology
In one study, post-cricoidectomy epithelial cells from patients suffering from laryngopharyngeal reflux were examined and shown to contain pepsin while the control group cells did not.[3] Inactivated pepsin at pH 7 is taken into cells and subsequently reactivated within cells, causing mitochondrial damage and overall cell damage. Cell damage was prevented by blocking the uptake of pepsin into cells.
History and Physical
As stated previously, laryngopharyngeal reflux encompasses many symptoms that could bring a patient into the clinic. That being said, hoarseness is the most prevalent symptom in laryngopharyngeal reflux (100%) with none of the patients with the more common condition of gastroesophageal disease (GERD) reporting hoarseness.[1]
Patients can have a multitude of other symptoms including globus sensation, chronic throat clearing, heartburn, and regurgitation.[4] Patients with laryngopharyngeal reflux typically have upright, or daytime, reflux with good esophageal motor function.[5] This is compared to supine or nocturnal symptoms in patients with reflux who had esophageal motor dysfunction.[6] Patients with gastroesophageal reflux (GERD) have dysfunction of their lower esophageal sphincter in contrast to the upper esophageal sphincter pathology seen in laryngopharyngeal reflux.[7]
Reflux Symptom Index
The reflux symptom index (RSI) is a validated questionnaire to determine the likelihood of positive results of dual diagnoses.[8] RSI greater than 10 is correlated with a high likelihood of reflux pathology. It is an eight-item questionnaire given to patients to score the severity of their symptoms on a scale of 0 to 5 (5 being the most severe). It asks the patient to score:
- The degree of hoarseness
- Frequency of throat clearing
- Degree of throat mucus or postnasal drip
- Dysphagia
- Coughing after eating or lying down
- Breathing difficulties
- Chronic cough
- Globus sensation
- Heartburn
On a physical exam, an otolaryngologist can perform laryngoscopy as well as videostroboscopy. Posterior thickening and pachyderma of laryngeal posterior commissure and post-cricoid mucosa have been associated with laryngopharyngeal reflux.[9] Granulomas of the vocal process have also been highly associated with the disease.[10] Edema along the undersurface of the vocal fold from the anterior to the posterior commissure has a fair sensitivity and specificity for the presence of LPR.[6]
Evaluation
Detection of retrograde flow of stomach acid into the upper aerodigestive tract has been considered the gold standard. This is tested via a single probe or dual probe pH testing. Pathologic reflux is considered present when 0.1% of the study time has a pH of less than 4.0.[11] Radiologic imaging has not been shown to increase the sensitivity of diagnosis. In a study comparing pH probe monitoring versus imaging, videofluoroscopy showed a sensitivity of reflux diagnosis via imaging ranged from 25% to 33%.[12] Esophagrams showed a sensitivity of 20% with a specificity of 64% to 90%.[12]
Treatment / Management
Lifestyle modifications are the first step in management. This includes weight loss, small meal size, refraining from lying down within 3 hours of a meal, eating low fat and low acid diet, avoiding carbonated or caffeinated beverages, stopping tobacco use, and reducing alcohol intake.
If these measures fail to achieve results, medications such as histamine-2 receptor antagonists and proton pump inhibitors can be used to suppress acid production. Surgical therapy such as Nissen fundoplication can also be advocated to decrease symptoms.
Differential Diagnosis
Laryngeal complaints similar to laryngopharyngeal reflux manifestations have a wide differential. Most commonly, laryngopharyngeal reflux may be misdiagnosed as gastroesophageal reflux (GERD). Distinctions between these two common conditions have been stated elsewhere in this chapter.
Prognosis
Long-term untreated laryngopharyngeal reflux will lead to chronic vocal injury with resultant scarring of the true vocal folds. Laryngopharyngeal reflux may also be related to untreated GERD, which can lead to Barrett esophagitis if left untreated. Also, one study showed in a retrospective chart review that untreated laryngopharyngeal reflux can lead to subglottic stenosis over time.[13]
Complications
As stated above, significant long-term complications of LPR can occur if the disease is left untreated on unrecognized. Commonly listed complications include:
- Chronic cough
- Recurrent laryngitis
- Oral cavity disorders/ulcers
- Recurrent bronchopulmonary injury/infections
In rare instances, LPR has been identified as a risk factor for laryngeal carcinoma.[14]
Consultations
If a patient continues to have symptoms of hoarseness, dyspnea, and chronic sore throat despite lifestyle changes, an otolaryngologic referral is a good option. Also, a gastroenterologist may need to get involved for possible esophagoscopy to ensure no malignant process is occurring.
Deterrence and Patient Education
Laryngopharyngeal reflux can usually be treated with lifestyle modifications that will pay dividends in other aspects of their health as well. With time, these symptoms can resolve, and the need for anti-reflux medication will abate. For this reason, patient education becomes a crucial aspect of management. Patients need ongoing education on lifestyle modifications including weight loss, reduction in portion size of the meal, and refraining from lying down within 3 hours of a meal. Dietary modifications including adherence to low fat and low acid diet, avoiding carbonated or caffeinated beverages, and reducing alcohol intake is imperative.
Enhancing Healthcare Team Outcomes
Laryngopharyngeal reflux appears to be a common yet under-diagnosed. Despite the available drugs and surgical procedures to manage this condition, it is important to recognize that lifestyle modifications are first-line therapy for this condition. To achieve this goal, an interprofessional team approach is needed. In addition to astute clinicians, treatment and management of LPR requires specialty trained nurses to help educate the patient on lifestyle modifications including weight loss, reduction in portion size of the meal, and refraining from lying down within 3 hours of a meal. Education on dietary modifications including adherence to low fat and low acid diet, avoiding carbonated or caffeinated beverages, and reducing alcohol should be provided by primary care nurses as well as dieticians. When medical therapy is required, the management of the patient requires clinical pharmacists to help assist the clinical team in providing the lowest therapeutic dose of therapy and in adjusting other medications to minimize adverse interactions. A collaborative interprofessional team across multiple disciplines can help improve outcomes in patients with LPR. [Level V]