Diagnostic accuracy of a 3-hr continuous intraluminal pH monitoring of the lower esophagus in the evaluation of gastro-esophageal reflux in infancy

Comparing bedside methods of determining placement of gastric tubes in children

PURPOSE

The purpose of this study was to compare the accuracy and predictive validity of pH, bilirubin, and CO2 in identifying gastric tube placement errors in children.

DESIGN AND METHODS

After the tube was inserted into 276 children, the CO2 monitor reading was obtained. Fluid was then aspirated to test pH and bilirubin.

RESULTS

Lack of ability to obtain tube aspirate was the best predictor of NG/OG placement errors with a sensitivity of 34.9% and a positive predictive value of 66.7%. Measuring pH, bilirubin, and CO2 of tube aspirate was less helpful.

PRACTICE IMPLICATIONS

Healthcare providers should suspect NG/OG tube misplacement when no fluid is aspirated.

[Esophageal pH-metry in children with recurrent respiratory events: diagnosis value of a day time esophageal pH monitoring]

Detection of a gastroesophageal reflux in the aetiology of recurrent respiratory diseases is the main indication of continuous gastroesophageal pH-metry in children. The aim of the study was to measure the diagnostic value of a daytime esophageal pH monitoring in children with recurrent respiratory diseases.

METHODS

One hundred seventeen continuous esophageal pH monitoring of 5 +/- 3 year-old children presenting recurrent respiratory diseases have been reviewed. For each record, an analysis of the total record period, then the diurnal record, then the nocturnal record period was performed. The reflux index, the number of reflux per hour, and the number of long lasting reflux (> 5 min) per hour were compared between different periods (total, diurnal, and nocturnal).

RESULTS

For the reflux index, the sensibility, the specificity, the positive predictive value and the negative predictive value of the awake period in comparison with the continuous 24 h record, considering the same standards for both periods, were 97%, 46%, 72% and 92% respectively. The ROC graph analysis showed that the cut-off adaptation for the reflux index and for the number of reflux per hour, did not allow to improve the day pH-metry performance, since sensibility and specificity moved respectively from 66% to 56% for reflux index, and from 75% to 56% for the number of reflux per hour.

CONCLUSION

In children explored for recurrent respiratory diseases, the night record has a bad diagnostic value and a negative diurnal record is strongly predictive of absence of pathological gastroesophageal reflux in these children. Because of the absence of paediatric specific standards for this disorder, it is not possible to reduce the recording time to the diurnal period.

The role of gastro-oesophageal reflux in the aetiology of SIDS

Gastro-oesophageal reflux (GOR) has been identified as a possible cause of SIDS. Several features of GOR unique to infants presenting with apparent life-threatening events (ALTEs) have led to its 'pathogenic' definition. One is that the life-threatening apnoea itself is initiated by GOR, another is that the ALTE relates to prolonged reflux during sleep, in a vulnerable sleep-state, and finally that the ALTE relates to excessive quantities of GOR. The presumption of GOR 'pathology' as a cause of SIDS however, is questionable in these susceptible infants for three reasons: firstly, GOR is physiological and occurs in most infants; secondly, there is no general consensus on what constitutes normal physiological reflux, and thirdly, variation in the recording technique and methods of data analysis and interpretation may account for the differences between study groups. It seems likely therefore if GOR is implicated in SIDS, additional factors are involved. Under certain circumstances, physiological GOR may trigger life-threatening apnoea in apparently healthy infants, that leads to SIDS. One mechanism that could explain such a death is reflex apnoea by stimulation of laryngeal chemoreceptors (LCR) during sleep. The conditions under which this could be fatal are the occurrence of gastric contents refluxed to the level of the pharynx during sleep, in the young infant who has depressed swallowing and arousal. That is, the occurrence of GOR to the level of the pharynx during sleep, an infrequent event that is usually innocuous, could be converted to a fatal event if swallowing is impaired and arousal depressed, by a variety of mediating factors such as prone sleeping, prematurity, sedatives, seizures or upper respiratory tract infections. The identification of LCR responses, particularly in prone sleeping and premature infants provide further evidence that this mechanism may be implicated in the aetiology of SIDS in apparently healthy infants.

Does the size of nasogastric tubes affect gastroesophageal reflux in children?

BACKGROUND

To evaluate the effects of nasogastric tube insertion and different nasogastric tube sizes on gastroesophageal reflux in children.

METHODS

During a prospective randomized study, 29 patients aged 1 month to 4 years (median, 9 months) underwent 24 hours of continuous esophageal pH monitoring to rule out gastroesophageal reflux as the cause of severe pulmonary problems. Each patient was monitored without nasogastric tube for 16 hours (baseline), and thereafter the first nasogastric tube, small (8-Fr) or large (10-Fr or 12-Fr), was placed. Four hours later, the original nasogastric tube was replaced by a new one of large (instead of small) size or of small (instead of large) size. We selected the times of wakefulness in these study periods and compared the number of reflux episodes (NREs), the number of reflux episodes that lasted more than 5 minutes (NRE>5), and the percentage of time with esophageal pH less than 4 (PTP<4).

RESULTS

The 12-Fr group in comparison with the 8-Fr group and baseline showed significant difference (P<0.05) in the NRE>5 and PTP<4 parameters. No significant differences were found when comparing 8-Fr versus 10-Fr groups and baseline. In children with (n = 20) and without (n = 9) gastroesophageal reflux, comparison of the various reflux parameters between baseline and the different sizes of nasogastric tubes showed the same results.

CONCLUSIONS

Size of the nasogastric tubes is a significant factor in predisposing the child to gastroesophageal reflux. Large nasogastric tubes interfere with the clearance of the refluxed acid from the esophagus.

Nap studies underestimate the incidence of gastroesophageal reflux

Shorter nap (1 and 4 hr) pH studies inaccurately diagnosed gastroesophageal reflux (GER) in a group of infants evaluated for apparent life threatening events (ALTE) and recurrent apnea. Twenty-five infants with a postconceptional age of 42 +/- 8 SD weeks, were evaluated by 12-hr polysomnography (PSG). Prior to the start of the 12-hr study, a 1-hr Tuttle Test was performed. By means of the 12-hr study 11 infants were diagnosed as having GER while the Tuttle Test incorrectly diagnosed 6 infants, 5 as having no GER and 1 as having GER when no GER was present (P < 0.05). No differences in the amount of periodic breathing (PB) or apnea density (AD) were found between the two studies. In addition, the first 4 hr of the 12-hr PSG segment following the first feeding was evaluated separately. In the 4-hr segment, two of the infants were incorrectly diagnosed as not having GER. In this study, nap studies failed to diagnose all of the infants with GER. Therefore, we conclude that an infant cannot be accurately diagnosed as not having GER without prolonged pH recording.

Gastro-oesophageal reflux in children: comparison of different durations, positions and sleep-awake periods of pH monitoring in the same patient

A group of 72 children (mean age: 21.7 months, range: 14 days-19 years) with symptoms of gastro-oesophageal reflux were investigated by 22 h pH monitoring. Using a Proxeda software, we compared, in the same patient, the specificity and sensitivity of pH monitoring during 3 h, 6 h, 12 h, 12 nocturnal hours and 3 postprandial hours, as well as the influence of position and the sleep and alert periods. Results showed that all the short pH monitorings were statistically less sensitive than 22 h pH monitoring (P < 0.025). As regards specificity, only the 12 nocturnal hours pH monitoring was not statistically different from the 22 h pH monitoring. Gastro-oesophageal reflux was more frequent when the patient was awake than during sleep. pH monitoring seemed more reliable in the recumbent than in the upright position. We conclude that long-term pH monitoring (22 h) is the test of choice to diagnose gastro-oesophageal reflux because it included sleep and alert periods as well as different positions.

Abbreviated esophageal pH monitoring as an indication for fundoplication in children

Intraesophageal pH recordings from 40 patients with abnormal studies who underwent fundoplication during a 1-year period were evaluated. Scores were recalculated for the first 12, 16, and 20 hours, respectively. Five of the recordings were for less than 24 hours, but were grossly abnormal and mathematically could not have normalized at 24 hours. The percentage of studies which were normal at 12, 16, and 20 hours were 20%, 15%, and 0%, respectively. One fifth of the patients would have been denied a fundoplication based on 12-hour results. In addition, 75 consecutive pH recordings were evaluated prospectively. Total scores were determined for the first 12, 16, and 20 hours with accuracies of 85%, 93%, and 92%, respectively. The sensitivity of 12-hour monitoring was only 78%. All abbreviated studies had a low rate of false positives; however, any false positives may be significant when used to determine the need for an operation. Abbreviated studies were associated with high false-negative rates (up to 52% for the 12-hour studies) for the calculated mean duration of sleep reflux, a parameter that has been found to be useful in identifying patients with respiratory symptoms secondary to gastroesophageal reflux. The use of abbreviated pH monitoring is discouraged.

Gastroesophageal reflux in infants and children

Gastroesophageal reflux is a common disorder in infants and children worldwide. This paper is intended to provide updated information on various aspects of the disease. It is hoped that this review will increase awareness and stimulate research in this field.

The interpretation of oesophageal pH monitoring data

Continuous monitoring of oesophageal pH is regarded as the gold standard for all reflux investigations. However, since gastro-oesophageal reflux is considered a normal phenomenon which occurs to a certain extent in each individual, the distinction between "normal" and "abnormal" is not always obvious and is not possible to achieve with a single test. Moreover, data depend on technical hardware such as recording devices and electrodes together with such patient characteristics as age, position, activity, and medication. Although much literature on pH monitoring has appeared recently, many investigations have failed to take into account the basic principles that are of major importance for any biomedical test such as reproducibility, sample reliability, and indications. There is a need to standardize the technique in order to compare studies performed in different centres, provided the technique is reproducible.

Gastroesophageal reflux: update on pathogenesis and diagnosis

The study of GER has been hindered by the lack of a good animal model and by the presence of some reflux in all normal individuals. By the painstaking process of studying normal infants, children, and adults, it is becoming evident that abnormalities of acid clearance, especially in the recumbent position (or during sleep), may be critical to an understanding of this disorder. As more is learned about the conditions surrounding "normal" reflux, it will be possible to refine the techniques of diagnosis and thereby identify the abnormal with more security.

A unique teletransmission system for extended four-channel esophageal pH monitoring in infants and children

A new computerized telemetry system for extended esophageal pH monitoring is prospectively evaluated and compared with other diagnostic modalities in 38 pediatric patients suspected of having gastroesophageal reflux (GER). Unique circuitry allows connection of 1.5 mm diameter antimony electrodes to a patient-worn digital recorder that continuously samples pH at four levels from pharynx to distal esophagus. Ambulatory studies in a "physiologic" environment are possible and data is teletransmitted by the satellite computer to the central laboratory for analysis. Of 41 studies completed, four were lost to interpretation because of battery, electrode, or computer failure. Thirty-seven studies could be analyzed in five clinical groups: emesis and failure to thrive; status post esophageal atresia repair; apnea/bradycardia; central nervous system damage; and status post antireflux procedure. Pathologic GER was noted 14 times and an antireflux procedure was clinically required in 13 instances. In five cases the upper GI series failed to detect the GER. Twenty-three studies showed no GER, and the clinical symptoms resolved with appropriate medical therapy in 21 cases. The upper GI series demonstrated GER five times in this group. In the nine instances that esophagoscopy/biopsy was employed, the pH study findings were uniformly confirmed. This computerized system provided a technically complete and interpretable study 90% of the time. Based on patient outcome, the extended pH monitoring was 92% accurate in detecting clinically important GER with a sensitivity of 87% and specificity of 93%. The upper GI series demonstrated a 69% accuracy with a 60% sensitivity and 64% specificity (P = .01).(ABSTRACT TRUNCATED AT 250 WORDS)