Pharyngeal pH Research Articles

Pharyngeal pH monitoring in 222 patients with suspected laryngeal reflux

To determine the existence of and characterize gastroesophagopharyngeal reflux in patients with symptoms of airway irritation, we monitored pharyngeal pH over a 24-hour period in 222 consecutive patients. Pharyngeal reflux was defined as a drop in pH to less than 4 at the pharyngeal sensor, which occurred simultaneously with acidification of the distal esophagus. Patients were divided into two groups: those with pharyngeal reflux (PR+) and those without (PR−). The Mann-Whitney U test and Student's t test were used to assess intergroup comparisons. Episodes of pharyngeal reflux (range 1 to 36, average 4.4) were identified in 90 PR+ patients (40%). No pharyngeal reflux was identified in the remaining 132 patients (PR−). Episodes of pharyngeal reflux were rapidly cleared (average duration 1.5 minutes), and occurred while in the upright position in 77 (86%) of 90 patients and while in the supine position in 11 (12%) of 90 patients. Twenty-three patients (25%) experienced symptoms in association with an episode of pharyngeal reflux. In the distal esophagus, the percentage of time the pH was below 4 during the upright position and the total percentage of time the pH was below 4 were greater in PR+ patients (6.4% and 5.8%, respectively) when compared to PR− patients (2.6% and 2.6%, respectively). Laryngoscopic findings did not distinguish PR+ from PR− patients. Pharyngeal reflux occurs most commonly in the upright position and can be identified in more than 40% of patients thought to have acid-induced laryngeal symptoms. Even though these episodes are short lived and rapidly cleared, symptoms occur concomitantly in 25% of patients with proven pharyngeal reflux. Patients with laryngeal symptoms and documented pharyngeal reflux have greater amounts of esophageal reflux when compared to patients with laryngeal symptoms and no demonstrable pharyngeal reflux.

Outcomes of acid suppressive therapy in patients with posterior laryngitis

Objective: To evaluate the results of acid suppressive therapy (AST) in posterior laryngitis (PL) patients with and without documented pharyngeal acid reflux (PAR). Methods: The charts of all patients with PL who received AST and who had undergone pharyngeal pH monitoring were reviewed. Results of AST in patients with PL with and without documented PAR were evaluated by laryngeal examination, symptom scores, and self-reported overall benefit. Results: Thirty-nine patients with PL had received AST and undergone pharyngeal pH monitoring. Follow-up ranged from 2 to 27 months. Laryngeal findings were improved in patients with and without PAR. Pretreatment total symptom scores were significantly greater than that of posttreatment in patients with and without documented PAR. Overall benefit from AST was reported by the majority of PL patients with and without documented PAR. Conclusion: These findings support the use of AST to reduce or eliminate signs and symptoms in PL regardless of documentation of PAR. (Otolaryngol Head Neck Surg 2001;124:16-22.)

Diagnosis and management of supra-esophageal complications of reflux disease.

Supra-esophageal reflux disease may be manifested in numerous ways, including reflux laryngitis, chronic cough, chronic sinusitis, and dental enamel loss. The mechanisms of pharyngeal and laryngeal reflux are not clearly defined, and standard reflux testing does not consistently demonstrate supra-esophageal reflux. The diagnosis is usually based on clinical suspicion when other causes of symptoms are not found and on the patient's response to empiric acid suppression. With the development of triple-probe pH monitoring, through which pharyngeal pH can be assessed along with esophageal pH, the physician may now be able to demonstrate pharyngeal reflux in relation to patient symptoms. Therapy consists primarily of behavioral modification and aggressive acid suppression, although some alternative therapies exist.

Pharyngeal pH measurements in patients with laryngeal symptoms prior to and during proton pump inhibitor therapy

Pharyngeal pH measurements in patients with laryngeal symptoms prior to and during proton pump inhibitor therapy

24-H Pharyngeal pH Monitoring in Healthy Volunteers: A Normative Study

Background: Gastropharyngeal reflux has been associated with disorders of the upper and lower airways. It may be shown by pharyngeal pH-metry, but reports on normality in healthy volunteers are scarce. No definite consensus has been reached considering the upper limit of normality (ULN). The aim of the present study was therefore to quantify the occurrence of pharyngeal acid exposure (pH < 4) in healthy volunteers and, further, to examine its relation to acid exposure of the oesophagus and oesophageal motility and its occurrence in relation to age, sex, and body position. Methods: Forty healthy volunteers underwent ambulatory 24-h pH-metry, using antimony electrodes positioned 2 cm above the upper oesophageal sphincter and 5 cm above the lower oesophageal sphincter on the basis of manometry. Technical artefacts were excluded before calculation of all results. Results: Gastropharyngeal reflux occurred in most healthy volunteers without any significant relation to age, sex, or body weight. Pharyngeal acid reflux occurred mainly in the upright position. The ULN for pharyngeal acid exposure time was assessed to 0.9% (0.2% after exclusion of mealtimes). The ULN for the number of acid events in the pharynx was 18 (6.1). The corresponding ULNs for the oesophagus were 7% and 84. Conclusion: Gastropharyngeal reflux may be effectively monitored by ambulatory pH-metry. The present study provides reference limits, a prerequisite for evaluating the pathophysiologic importance of the phenomenon.

Cricopharyngeal myotomy does not increase the risk of esophagopharyngeal acid regurgitation.

It is not known whether cricopharyngeal myotomy predisposes to esophagopharyngeal regurgitation. Using ambulatory, dual pharyngeal, and esophageal pH monitoring before and after cricopharyngeal myotomy, our aim was to determine the effect, if any, of myotomy on the frequency of esophagopharyngeal acid regurgitation. We studied prospectively 18 patients who underwent cricopharyngeal myotomy for pharyngeal dysphagia (10 Zenker's, eight neurogenic dysphagia), of whom 17 agreed to undergo dual pH monitoring preoperatively, and 10 who agreed to both pre- and postoperative monitoring. Symptoms of gastroesophageal reflux disease were present in 30%. Cricopharyngeal myotomy significantly reduced basal upper esophageal sphincter pressure by 49%, from 37+/-5 mm Hg to 19+/-3 mm Hg (p = 0.007). Esophagopharyngeal regurgitation was a rare event and the frequency of it did not differ between patients and healthy controls. Preoperatively, three regurgitation events in two patients did not differ from the postoperative frequency of a total of two events in the same two patients. Increased esophageal acid exposure is common and esophagopharyngeal regurgitation is rare in unselected patients undergoing cricopharyngeal myotomy for pharyngeal dysphagia. Myotomy does not increase the frequency of esophagopharyngeal acid regurgitation in such patients.

Cricopharyngeal myotomy does not increase the risk of esophagopharyngeal acid regurgitation

OBJECTIVE: It is not known whether cricopharyngeal myotomy predisposes to esophagopharyngeal regurgitation. Using ambulatory, dual pharyngeal, and esophageal pH monitoring before and after cricopharyngeal myotomy, our aim was to determine the effect, if any, of myotomy on the frequency of esophagopharyngeal acid regurgitation. METHODS: We studied prospectively 18 patients who underwent cricopharyngeal myotomy for pharyngeal dysphagia (10 Zenker’s, eight neurogenic dysphagia), of whom 17 agreed to undergo dual pH monitoring preoperatively, and 10 who agreed to both pre- and postoperative monitoring. RESULTS: Symptoms of gastroesophageal reflux disease were present in 30%. Cricopharyngeal myotomy significantly reduced basal upper esophageal sphincter pressure by 49%, from 37 ± 5 mm Hg to 19 ± 3 mm Hg ( p = 0.007). Esophagopharyngeal regurgitation was a rare event and the frequency of it did not differ between patients and healthy controls. Preoperatively, three regurgitation events in two patients did not differ from the postoperative frequency of a total of two events in the same two patients. CONCLUSIONS: Increased esophageal acid exposure is common and esophagopharyngeal regurgitation is rare in unselected patients undergoing cricopharyngeal myotomy for pharyngeal dysphagia. Myotomy does not increase the frequency of esophagopharyngeal acid regurgitation in such patients.

Esophagopharyngeal acid regurgitation: Dual pH monitoring criteria for its detection and insights into mechanisms

Background & Aims: A valid technique for the detection of esophagopharyngeal acid regurgitation would be valuable to evaluate suspected reflux-related otolaryngologic and respiratory disorders. The aim of this study was to derive pH criteria that optimally define esophagopharyngeal acid regurgitation and to examine patterns of regurgitation. Methods: In 19 healthy controls and 15 patients with suspected regurgitation, dual or quadruple pH sensors were used to monitor pharyngeal and esophageal pH. For each combination of the 2 variables, ΔpH and nadir pH, proportions of pH decreases that occurred during or independent of esophageal acidification were calculated to determine the likelihood that an individual pharyngeal pH decrease was a candidate regurgitation event or a definite artifact. Results: Overall, 92% of pharyngeal pH decreases of 1–2 pH units and 66% of pH decreases of this magnitude reaching a nadir pH of <4 were artifactual. Optimal criteria defining a pharyngeal acid regurgitation event were a pH decrease that occurred during esophageal acidification, had a ΔpH of >2 units, and reached a nadir of <4 units in less than 30 seconds. Regurgitation occurred more frequently in subjects in an upright (32 of 35) than in a supine (3 of 35 events; P ≤ 0.0001) position and was more frequently abrupt (synchronous with esophageal acidification) than delayed ( P ≤ 0.05). Conclusions: Accepted criteria for gastroesophageal reflux are not applicable to the detection of esophagopharyngeal acid regurgitation, and most regurgitation occurs abruptly and in upright position. GASTROENTEROLOGY 1999;117:1051-1061

Revelations about 24-hour ambulatory pharyngeal Ph monitoring

Revelations about 24-hour ambulatory pharyngeal Ph monitoring

Spectrum of Supraesophageal Complications of Gastroesophageal Reflux Disease

There is a growing body of clinical and research evidence to support the role of gastroesophageal reflux in the etiology of certain disorders occurring in structures located above the body of the esophagus. These supraesophageal complications have only recently been identified but substantiation of the role of gastroesophageal reflux has been difficult and sometimes impossible with the technology currently available. This introductory article to the clinical issues involved in supraesophageal complications of GERD presents several index cases and asks far more questions than it gives answers about these patients. Clinical evidence supporting the role of GERD is discussed and the results of therapy reviewed. Education of the practicing physician to the role of supraesophageal complications of GERD is urged to help recognize the likelihood of such clinical conditions. There is a real need for additional clinical use and evaluation of multi site intraesophageal and pharyngeal pH probes in patients with suspected supraesophageal complications of GERD. More importantly, development of new techniques for measuring micro reflux events and sophisticated methods for determining the duration of acid exposure in tissues above the esophagus is essential. Finally, more prospective controlled outcome studies of patients with supraesophageal complications of GERD are needed utilizing specific treatment algorithms.

The Incidence of Regurgitation above Upper Esophageal Sphincter: Laryngeal Mask Airway vs Endotracheal Tube

Background: From a clinical perspective, the regurgitation of the gastric contents above the upper esophageal sphincter has greater clinical relevance than gastroesophageal reflux. The authors investigated the incidence of regurgitation of gastric contents above the upper esophageal sphincter associated with the laryngeal mask airway(LMA) and the endotracheal tube(ETT) by methylene blue(50mg) gelatine capsule and pH probe in positive pressure ventilated patients during long surgical procedures . Methods: Sixty patients scheduled for elective orthopedic surgery with a standardized general anesthetic technique were randomly allocated to receive either a LMA(n=34) or a ETT(n=26) for airway management. For the detection of regurgitation episodes during anesthesia, a pH monitoring probe was positioned in the hypopharynx 30 minutes before induction and a methylene blue capsule was swallowed just before induction. At the end of anesthesia, the episodes of regurgitation of gastric contents above upper esophageal sphincter were analyzed according to the pharyngeal blue staining or pH≤4. Results: There were no episodes of regurgitation of gastric contents(pH≤4 or/and methylene blue staining) above the upper esophageal sphincter detected during the course of measurement. There was no clinical evidence of aspiration in either group. Conclusions: In comparison with ETT, the use of LMA does not appear to result in increased incidence of regurgitation of gastric contents above upper esophageal sphincter in positive pressure ventilated patients during long surgical procedures. (Korean J Anesthesiol 1997; 32: 539∼546)

Detection of acid regurgitation with a pharyngeal pH electrode: Validation of measurement criteria

Detection of acid regurgitation with a pharyngeal pH electrode: Validation of measurement criteria

Globus pharyngeus: radiographic evaluation and 24-hour pH monitoring of the pharynx and esophagus in 22 patients.

The authors correlated the radiographic evaluation and 24-hour pH monitoring of the pharynx and the esophagus in patients with globus pharyngeus. Radiographic examination of the pharynx of 22 patients (13 women and nine men, aged 23-73 years [mean, 47 years]) included videofluoroscopy and static radiography. Twenty-four-hour double-probe pH monitoring of the pharynx (abnormal, pH < 4) and esophagus (abnormal, 6% or more total acid exposure) was performed in all patients. Radiographic results were normal in 17 patients; results were abnormal in five, with four having pharyngeal dysfunction and one showing a persistent cricopharyngeal impression. Zenker diverticulum was not seen. Results at pH monitoring of the pharynx and esophagus were normal in 20 and 18 of the 22 patients, respectively. In four of five patients with abnormal radiographic studies of the pharynx, results of pharyngeal pH monitoring were normal. Most patients with globus pharyngeus had normal results at pH monitoring and radiographic examination of the pharynx.

Pharyngeal swallowing. The major factor in clearance of esophageal reflux episodes.

This study defined the clearance mechanisms of naturally occurring reflux episodes in normal subjects and patients with gastroesophageal reflux disease. Previous studies on acid clearance have been performed in the laboratory setting in supine subjects using acid instillation and stationary motility. The mechanisms of clearance have not been studied using ambulatory pH and motility monitoring. A new system capable of monitoring simultaneously for 24 hours pharyngeal pressure, esophageal motility, and pH was used to study the clearance of naturally occurring reflux episodes in 10 normal subjects and 18 patients with gastroesophageal reflux disease. Esophageal contraction waves were classified as primary (i.e., initiated by a pharyngeal swallow) and secondary (i.e., unrelated to a pharyngeal swallow). A total of 1288 reflux episodes were analyzed, during which 2781 contraction waves occurred. Clearance (i.e., restoration of pH to > 4) occurred after primary peristalsis in 83% of reflux episodes. An additional 11% were cleared by pharyngeal swallows without an esophageal body response. Secondary waves were rare and when they occurred, only 19% were peristaltic. Secondary peristalsis cleared only 9 of the 1288 reflux episodes. Patients and normal subjects cleared reflux episodes similarly. Baseline swallowing frequency was 0.87/min during the daytime and increased to 2.59/min (p < 0.01) during daytime reflux episodes. Swallowing frequency in response to nighttime reflux episodes was less (1.42/min; p < 0.05). Pharyngeal swallowing is the most important mechanism for esophageal acid clearance. Secondary waves are rare, usually disorganized, and unimportant in clearing a reflux episode. During sleep, the mechanisms of clearance are depressed.

Gastropharyngeal reflux in infants and children. A pharyngeal pH monitoring study.

Gastroesophageal reflux has been shown to play an important role in chronic and acute inflammatory disorders of the airway. In particular, gastroesophageal reflux has been suggested to be the cause of pharyngolaryngeal problems, according to the literature, at any age. However, to our knowledge, the presence of acid in the pharynx in pathological cases has not yet been proved. A series of eight patients (aged 2 months to 7.5 years) with recurrent acute laryngotracheitis underwent a two-channel pH monitoring for 23 to 24 hours. One pH probe was placed in the lower esophagus, the other in the pharynx, at the level of the epiglottis. Acid gastroesophagopharyngeal reflux was demonstrated in every patient. A significant difference with a series of six control subjects was noted in terms of esophageal and pharyngeal pH monitoring. The most significant item is the total time the pH in the pharynx was below 6. Despite the limited number of patients, this study suggests the role of gastroesophageal reflux in recurrent laryngotracheitis in infants and children.

Gastroesophageal reflux as an etiologic factor in laryngeal complications of intubation.

Significant complications are encountered in some patients as a result of prolonged endotracheal intubation. The finding of low gastric pH values at postmortem examination in patients whose larynx was severely traumatized after endotracheal intubation suggested that gastroesophageal reflux (GER) is an important factor in the pathogenesis of these problems. To evaluate the occurrence and character of GER as well as its effects upon the larynx and trachea of intubated patients, clinical observations and several animal models were employed. Monitoring of pH values for GER was performed in intubated patients both in the operating room and the intensive care unit with a 40% incidence of GER in ICU patients not receiving antacid therapy. After exposure to gastric juice, marked inflammation and necrosis were observed in the larynx of rabbits, and a significant reduction of mucociliary flow was found to occur in the dog's trachea. The physiology and mechanisms of these events are discussed and indicate that GER may play an important role in the development of permanent laryngeal and tracheal injury in the intubated patient. It is recommended that pharyngeal pH be monitored in intubated patients because their altered state of consciousness may predispose to gastric reflux. When GER is encountered, initiation of treatment should be undertaken because prevention is considerably more effective than subsequent treatment.

Silent regurgitation in day case gynaecological patients.

The effect of metoclopramide premedication on the incidence of gastric regurgitation and postoperative nausea and vomiting was studied in 101 women during gynaecological procedures performed under mask anaesthesia. All patients were premedicated orally with carmine red and temazepam. A treatment group of 48 women also received oral metoclopramide. Anaesthesia was standardised in both groups. None of the women regurgitated gastric contents. Pharyngeal pH was measured in the last 68 patients and found to be greater than 5 in all instances. Postoperative nausea and vomiting were significantly less frequent in the treatment group.

Airway protective and abdominal expulsive mechanisms in infantile regurgitation.

To define the expulsive and airway protective mechanisms involved in infantile regurgitation, we studied 15 infants (9 premature and 6 mature infants) with histories of frequent postfeeding regurgitation. In 13 infants we recorded pharyngeal pressure, pH, nasal and oral airflow, and abdominal respiratory movements. In two additional infants we recorded gastric pressure. In eight infants observations were made without intrapharyngeal recording devices. Distinctive abdominal regurgitation movements (RMs) immediately preceded 84% of regurgitation episodes. These RMs were characterized by one or more large brief increases in abdominal girth. In the two infants with gastric pressure recordings, large increases in gastric pressure, with duration and frequency characteristics similar to the RMs, immediately preceded regurgitation episodes. Thus, in contrast to the generally accepted concept that flow of gastric contents out of the stomach is passive during infantile regurgitation, we documented an active expulsive mechanism similar to that of vomiting in the adult. In all regurgitation episodes, upper airway closure occurred at the onset of the regurgitation movement. One or more swallows occurred immediately following RMs and prior to airway reopening in 97% of regurgitation episodes. Brief respiratory pauses occurred during regurgitation in all premature infants and occasionally in mature infants. Nasal regurgitation, coughing, and sneezing occasionally accompanied regurgitation episodes. Thus upper airway closure and swallowing prior to airway reopening were the most frequently observed airway protective mechanisms during regurgitation. Brief respiratory pauses, sneezing, and coughing may be secondary airway protective mechanisms. Nasal regurgitation likely represents immaturity of airway protective mechanisms.

Apnea associated with regurgitation in infants

To determine whether regurgitation might be a factor in the pathogenesis of apnea in certain infants, we compared the frequency of short and prolonged apnea immediately following regurgitation to that during control periods. Ten infants (nine preterm and one term) with histories of frequent regurgitation and also apneic spells were studied for 2 to 3 hours by monitoring nasal airflow, abdominal respiratory movements, electrocardiogram, pharyngeal pH, and pharyngeal pressure. In six of these infants additional observations were made without the intrapharyngeal recording devices. Fourty-four episodes of regurgitation were observed. Both prolonged apnea (P less than 0.05) and short apnea (P less than 0.01) occurred much more frequently during regurgitation than during the control period; however, the majority of prolonged apneic spells observed were unassociated with regurgitation. The increased frequency of apnea during regurgitation was not related to the presence of intrapharyngeal recording devices. Although nasal regurgitation was frequently associated with short apnea, no prolonged apnea was observed during the seven episodes of nasal regurgitation observed. The 14-fold increase in prolonged apnea frequency immediately following regurgitation supports the hypothesis for a causal relationship between apnea and regurgitation.

APNEA CAUSED BY REGURGITATION IN INFANTS

Regurgitation (R) of gastric contents is presumed to cause apnea in some infants. The mechanism of such apnea is unclear and polygraphic documentation is lacking. We recorded nasal airflow (flowmeter), abdominal movements, oral CO2 and EKG in 13 infants. Group A (9 preterm infants, age 2-4 wk and 1 term, age 1 wk) had a history of idiopathic prolonged apnea and ordinary post-feeding R episodes (spitting up); Group B (3 term infants, age 3 mo) had R only. R episodes were recorded in all infants (43 episodes in Group A and 10 in Group B). In 37 of 53 R episodes pharyngeal pressure and pH were recorded to aid in detection of R. In Group A most R episodes (92%) were immediately followed by either a short apnea (S-apnea = absent airflow ≥3 sec) or prolonged apnea (P-apnea = absent airflow for ≥20 sec or absent flow with heart rate ≤100 or cyanosis). Although most of the 100 P-apneas recorded in Group A were unrelated to R episodes, 8 P-apneas (occurring in 4 preterm infants) coincided with R (a statistically significant association in 3 infants: p<.01, p<.05, p<.05). All Group A infants had S or P-apnea, or both, during R. There were no S or P-apneas during R in Group B. Most P-apnea (83%) and S-apnea (78%) consisted of obstructive inspiratory efforts or breathing pauses combined with obstruction. We conclude: 1) regurgitation has little effect on breathing in healthy term infants but often causes S-apnea and, occasionally, P-apnea in infants with a past history of apnea; and 2) the mechanism of this apnea involves both airway obstruction and respiratory depression. Funding: NIH HD 10993.