Alkaline gastroesophageal reflux in infants and children

Gastroesophageal reflux scintigraphy: interpretation methods and inter-reader agreement

BACKGROUND

Scintigraphic imaging is a useful screening tool for patients with suspected gastroesophageal reflux. New scintigraphic interpretation methods have recently been introduced. This study was undertaken to evaluate the efficiency of various scintigraphic interpretation methods in the detection of gastroesophageal reflux and to measure their influence on inter-reader agreement.

METHODS

Scintigraphic images of 49 children with suspected gastroesophageal reflux were interpreted by three different methods: visual interpretation, time activity curves, and condensed images. The readings were performed by three specialists and a resident. The discordant results were resolved by a consensus reading done together by all interpreters based on the three different methods. The gastroesophageal refluxes were grouped according to their number, location and intensity.

RESULTS

Gastroesophageal reflux scintigraphy revealed 22 patients with negative results and 27 with positive results. The sensitivity, positive predictive value and specificity for each of the three specialists vs. the resident were 96%, 96% and 81% vs. 96%; 93%, 90% and 96% vs. 81%; and 90%, 86%, and 95% vs. 73%, respectively. The mean inter-observer reproducibility (κ value) was 0.910 for visual interpretation, 0.652 for time activity curves and 0.789 for condensed images. Twenty-seven percent of the results were discordant and most of these refluxes were of low grade (92%), low intensity (77%) and localization in the distal esophagus (54%).

CONCLUSION

Gastroesophageal scintigraphy is a useful tool for detecting patients with suspected reflux, and visual interpretation is better than the other two methods in terms of accuracy and inter-observer reproducibility.

Pediatric Gastrointestinal Nuclear Medicine

General localization of gastrointestinal bleeding through the use of labeled red blood cells may be performed in children, or (99m)Tc-pertechnetate may be used if a Meckel's diverticulum is suspected. As in adults, cholecystitis and biliary leak may be assessed in children via (99m)Tc-IDA derivatives. Gastroesophageal reflux can be evaluated by oral consumption of the child's usual diet labeled with (99m)Tc sulfur colloid. For the scintigraphic determination of pulmonary aspiration, a relatively high concentration of tracer within a drop of liquid is placed beneath the child's tongue followed by dynamic imaging of the respiratory tract. Colonic transit scintigraphy can aid in the identification and therapeutic decision-making in patients with functional fecal retention, the most common cause of chronic constipation in children. (18)F-DOPA positron emission tomography is useful for classifying pancreatic involvement in infantile hyperinsulinism as focal or diffuse, thereby differentiating between patients who should receive curative focal pancreatic resection versus those who should receive medical management. Assessment of protein-losing enteropathy can be conducted scintigraphically and, compared with fecal alpha-1 antitrypsin collection, the scintigraphic method can detect esophageal and gastric protein loss. Also, scintigraphic quantification of protein loss can be performed without the requirement for fecal collection. Intestinal inflammation in children with inflammatory bowel disease can be evaluated using (99m)Tc white blood cells. The scintigraphic method is safe, accurate, well-tolerated by children and complementary to endoscopy in most patients.

Do antireflux operations decrease the rate of reflux-related hospitalizations in children?

OBJECTIVE

Gastroesophageal reflux disease is extremely common in the pediatric population, and antireflux procedures are performed with increasing frequency. The objective of this study was to determine whether pediatric antireflux procedures are associated with a decreased rate of reflux-related hospitalizations.

METHODS

A study was conducted of pediatric patients who were undergoing antireflux procedures using data that were derived from the Washington State Comprehensive Hospital Abstract Reporting System and Vital Records. Patients were identified by a search of all records (1987-2001) for procedure codes that pertained to antireflux procedures in patients who were younger than 19 years. The number of hospitalizations for and rates of reflux-related events per patient-year before and after an antireflux procedure was calculated, and factors that were associated with higher antireflux procedure rates were examined.

RESULTS

A total of 1142 patients underwent antireflux procedures. The rate of reflux-related events declined sharply with age both before and after an antireflux procedure. The cohort was divided into 3 groups on the basis of age at first antireflux procedure (<1 year, 1-3 years, or 4-19 years), and the calculations of incidence rate ratios before to after an antireflux procedure were done within the same age strata. Results suggest an overall benefit of antireflux procedures in young children. For antireflux procedures that were performed in children who were older than 4 years, the benefit is less clear. Developmental delay was significantly associated with higher rates of reflux-related events among patients who underwent an antireflux procedure after age 4.

CONCLUSIONS

The rate of reflux-related events was lower after an antireflux operation for children who underwent an antireflux procedure before age 4. Older children, however, were hospitalized at equal rates before and after an antireflux procedure, and older children with developmental delay were hospitalized at greater rates after an antireflux procedure. These findings highlight the need to clarify the subjective and objective indications for antireflux procedures in infants and children.

A Study of the Link between Gastric Reflux and Chronic Sinusitis in Adults

Much discussion is taking place regarding the role of gastric reflux disease in the development and maintenance of chronic sinus disease. We studied 31 patients in a large urban private practice who had recalcitrant chronic sinusitis despite aggressive medical and surgical therapy. After we obtained information on the severity of each patient's sinus disease, we performed either double- or triple-catheter probe pH testing to assess the presence of reflux disease. Of the 30 patients who were successfully tested (1 patient did not tolerate probe testing), 25 demonstrated reflux disease, including 2 whose reflux reached the level of the nasopharynx. These 25 patients were placed on a proton-pump inhibitor (PPI) regimen and reassessed at least 1 month later. At follow-up, 14 of 15 evaluable patients demonstrated at least some improvement in their sinus symptoms, including 7 who experienced either a complete or almost-complete resolution of symptoms. The improvements in sinus symptoms corresponded with improvements in reflux symptoms. These findings suggest that antireflux therapy might play a role in the treatment of recalcitrant chronic sinus disease.

Eosinophilic esophagitis in children: symptoms, histology and pH probe results

AIM

To review the authors' experience with eosinophilic esophagitis.

METHODS

Between 1993 and 2001, the authors identified 12 patients with eosinophilic esophagitis defined on histologic criteria (> or = 20 eosinophils per high-power field in the distal esophageal epithelium). The authors reviewed medical records for details of clinical presentation; laboratory data; radiologic, endoscopic, and histologic findings; and the results of continuous esophageal pH probe monitoring.

RESULTS

Seventy-five percent of the patients were male. The median age at presentation was 10.8 years (range, 1-17 years). Commonly reported symptoms were dysphagia with solid food (66%), epigastric pain (42%), food impaction (50%), and vomiting (8%). Food allergy was reported in 50% and asthma in 33%. Peripheral eosinophilia (> 700/mm3) was found in 42%. Upper gastrointestinal series performed in eight patients, showed esophageal luminal narrowing in three. Computed tomography, performed in two patients, revealed thickening of the esophageal wall. Esophageal pH probe monitoring, performed in nine patients, revealed no abnormal acid reflux. All of the monitored patients had episodic alkalinization of the esophagus. Upper endoscopic analysis revealed white specks on the esophageal mucosa in 42%, esophageal narrowing in 33%, esophageal rings in 25%, and esophageal furrowing in 8%. The mean eosinophils per high-power field was 65 (range, 20-200). Histologic characteristics included juxtaluminar (33%) and peripapillary clusters of eosinophils (33%), increased papillary height (50%), and basal cell hyperplasia (34%).

CONCLUSION

Solid food dysphagia was the most common feature of eosinophilic esophagitis in our patients. Alkalinization of the esophagus was found in all nine pH probe recordings of eosinophilic esophagitis patients and may represent a previously unreported characteristic of the condition.

Evaluation of Gastric pH and Guaiac Measurements in Neonates Receiving Acid Suppression Therapy During Extracorporeal Membrane Oxygenation

STUDY OBJECTIVES

To assess gastric pH measurements, evaluate the frequency of guaiac-positive gastric aspirates, and characterize the appearance of gastric aspirates in neonates receiving acid suppression therapy during extracorporeal membrane oxygenation (ECMO).

DESIGN

Retrospective, observational study.

SETTING

Intensive care unit in a 225-bed tertiary care pediatric referral hospital.

SUBJECTS

Thirteen neonates receiving ECMO.

MEASUREMENTS AND MAIN RESULTS

Gastric pH measurements, guaiac test results, appearance of gastric aspirates, and ranitidine and antacid dosing were recorded. On ECMO day 1, mean+/-SD gastric pH was 4.3+/-2.8 in the five neonates whose pH was documented. Intravenous ranitidine 2.9+/-0.4 mg/kg/day was started in all neonates by ECMO day 2. Gastric pH was less than 4.0 in seven neonates; these low pH values accounted for only 10% of gastric pH measurements. The frequency of positive guaiac results in neonates with pH measurements below 4.0 was 27% compared with 41% for neonates with a gastric pH of 4.0 or greater (p=0.125). Guaiac tests were positive in 69 (42%) aspirates in 11 neonates. Of the guaiac-positive aspirates that had a corresponding pH measurement, 94% had a pH of 4.0 or greater. Guaiac-positive aspirates had evidence of bile (49%), antacid (17%), and blood (7%) in gastric fluid. In six patients, ranitidine dosages were increased to 3.9+/-0.6 mg/kg/day due to low pH and/or positive guaiac results. In two of these neonates, gastric pH remained below 4.0 in nine of 35 pH measurements despite increased ranitidine dosing. Guaiac results remained positive in all subsequent aspirates in five out of six of these neonates. No neonates developed clinically significant upper gastrointestinal bleeding (UGIB).

CONCLUSIONS

Gastric pH is variable in neonates receiving histamine2-receptor antagonist and antacid therapy during ECMO, and gastric pH of 4.0 or greater does not decrease the frequency of guaiac-positive aspirates. Higher gastric pH measurements are confounded by duodenogastric reflux and the presence of blood and/or antacid in gastric fluid. Motility agents in combination with acid suppression therapy for prevention of UGIB may be necessary in this setting based on gastric pH measurements, appearance of gastric aspirates, and guaiac testing.

Are scintiscans accurate in the selection of reflux patients for pyloroplasty?

BACKGROUND

Gastric emptying scintiscans are currently used to select reflux patients for added pyloroplasty at the time of fundoplication. The accuracy of this scan selection approach has been assumed. If preoperative scintiscans do not reliably predict postfundoplication gastric emptying, however, the decision to add pyloroplasty to the fundoplication operation may be inappropriate and even harmful.

METHODS

The authors studied 27 children prospectively before and after gastric fundoplication. Gastric emptying at 60 minutes was measured by double isotopic labeling of liquid (111In) and solid (99mTc) phases of a test meal specifically designed for label fixation. The authors' question involved the accuracy of preoperative gastric scintiscans in predicting postfundoplication delay of gastric emptying (DGE). An evaluation of pyloroplasty as an effective treatment for DGE was not part of the study design. Pyloroplasty was performed as a secondary operation in three of the study children, however, because they persisted with unrelieved symptoms of retching, fullness, and abdominal discomfort. Scintiscan-documented postfundoplication delay in gastric emptying was present in all three patients at 18, 58, and 12 weeks, respectively. Additional scintiscans were performed in these patients after pyloroplasty.

RESULTS

Gastric emptying of solids at 60 minutes did not show a significant change after a gastric fundoplication operation, although the trend was in the direction of a decrease (paired t test, P= .13). Liquid emptying at 60 minutes, however, was significantly increased (paired t test, P = .01). The variation in values between patients was wide, and the correlation between pre- and postoperative study results in the same patient was poor (r2 = 0.337 for solids and r2 = 0.116 for liquids). Most unexpectedly, scintiscans after postfundoplication pyloroplasty in the three patients with persistent symptoms showed no improvement in delayed gastric emptying on repeat scintiscan 42 to 117 weeks later.

CONCLUSIONS

The data suggest that preoperative scintiscan evidence for postfundoplication DGE is probably accurate for solid emptying but not for liquids, at least as measured by the double isotope methodology of our study. Preoperative scintiscans that use a liquid phase label only may be highly misleading for the prediction of postfundoplication DGE. Furthermore, pyloroplasty may not be useful as treatment even when postfundoplication delay in gastric emptying can be accurately anticipated or confirmed. A fundamental motility disorder of the gastric body seems to be more important than muscular resistance at the gastric outlet as a cause for postfundoplication DGE, and the most effective treatment approach remains unclear.

Simultaneous gastroesophageal pH monitoring and the diagnosis of alkaline reflux

The diagnosis of alkaline gastroesophageal reflux (AGER) by esophageal pH-monitoring is elusive because several other causes may raise esophageal pH above 7. This study approaches the issue by simultaneously recording esophageal and gastric pH with a 2.1 mm assembly of two antimony electrodes in refluxing (n = 69) and nonrefluxing (n = 40) children. On the basis of the information gathered, patients were divided into four groups: acid refluxers (GER, n = 40 or 57%), alkaline refluxers (AGER, n = 8 or 11%), alkalacid refluxers (AAGER, n = 15 or 22%), and silent refluxers or false negatives (SGER, n = 6 or 9%). Children with AGER could not be differentiated from other refluxers nor from controls by esophageal pH information alone. Prolonged gastric buffering or alkalinization could be documented in both AGER and AAGER children, indicating extended duodenogastric reflux (DGR) in them. The incidence of esophagitis was not significantly different between the groups of refluxers: 75% for AGER and AAGER, 73% for GER, and 67% for SGER. AGER, a disorder involving both pyloric and gastroesophageal barriers, is as significant a problem in children as in adults and may lead to severe complications even in the absence of excessive acid exposure. Monitoring esophageal pH alone is insufficient for making the diagnosis of AGER. The diagnosis can be made with little more expense and similar patient discomfort using the two-probe test. We suggest the need for a critical reassessment of the current antacid and prokinetic GER treatments and of antireflux operations which leave DGR intact while correcting GER.