A new formula proposal for placing pH-impedance catheters in pediatric patients.

INTRODUCTION: Esophageal pH-impedance monitoring is a tool for diagnosing gastroesophageal reflux in children. The position of the pH catheter is essential for a reliable reading and the current formulas for calculating catheter insertion length are not completely accurate. The aim of the present study was to develop a new formula for adequate insertion of the pH catheter. MATERIAL AND METHODS: A cross-sectional study was conducted on children that underwent pH-impedance monitoring and later radiographic control, to calculate the correct catheter insertion length. The documented variables were age, sex, weight, height, naris to tragus distance, tragus to sternal notch distance, sternal notch to xiphoid process distance, and initial insertion length determined by the Strobel and height interval formulas. A multivariate regression analysis was carried out to predict the final insertion length. Regression ANOVA and Pearson's adjusted R-squared tests were performed. RESULTS: Forty-five pH-impedance studies were carried out, 53% of which were in males. The age and weight variables were not normally distributed. In the initial regression model, the variables that did not significantly correlate with the final insertion length were: sex (P 0.124), length determined by the Strobel or height interval formulas (P 0.078), naris to tragus distance (P 0.905), and tragus to sternal notch distance (P 0.404). The final equation: 5.6 + (height in cm * 0.12) + (sternal notch to xiphoid process distance * 0.57) produced an R2 of 0.93 (P 0.000). CONCLUSIONS: This formula can be considered a valid option for placement of the pH-impedance monitoring catheter in pediatrics.

A comparison of endoscopic procedures performed at a tertiary care hospital before and during the SARS-CoV-2 pandemic.

INTRODUCTION AND AIM: SARS-CoV-2 emerged in 2019 and had a huge impact on the world. The area of endoscopy suffered great changes, causing a reduction in the number of procedures and its indications. The aim of our study was to compare the quantity, indication, and type of procedures in 2019 with those in 2020. METHOD: A retrospective, observational, analytic, and cross-sectional study was conducted, obtaining information from the endoscopy registry. The STROBE checklist was employed. STATISTICAL ANALYSIS: The quantitative variables were analyzed with descriptive statistics (measures of central tendency and dispersion) and the categorical variables with frequencies and percentages. The quantitative variables were compared, using the Student's t test/Mann-Whitney U test, and the categorical variables with contingency tables, using the Fisher's exact test. RESULTS: In 2019, a total of 277 procedures were performed, compared with 139 in 2020. Mean patient age was 98.53 months (61.46 SD) in 2019 and 77.02 months (59.81 SD) in 2020; 352 diagnostic procedures and 136 therapeutic procedures were carried out in 2019, compared with 51 diagnostic procedures and 88 therapeutic procedures in 2020. The number of diagnostic and therapeutic procedures were inverted (72.1%-36.7% and 27.9%-63.3%, respectively) (p<0.0001). Esophageal varices, upper gastrointestinal bleeding (UGIB), and foreign body extraction were the indications, in order of predominance in 2019, compared with foreign body extraction (p<0.05), UGIB, and esophageal varices in 2020. There were no differences regarding colonoscopy. CONCLUSION: There was a clear difference in indication and type of procedure, with an increase in foreign body extraction in preschoolers.

The consensus of the Asociación Mexicana de Gastroenterología on the diagnosis and treatment of gastroesophageal reflux and gastroesophageal reflux disease in infants.

Gastroesophageal reflux (GER) is a frequent normal phenomenon in children of any age. It is more common in infants, in whom the majority of episodes are short-lived and cause no other symptoms or complications, differentiating it from gastroesophageal reflux disease (GERD). The diagnosis and management of GER and GERD continue to be a challenge for the physician. Therefore, the aim of the Asociación Mexicana de Gastroenterología was to adapt international documents to facilitate their adoption by primary care physicians, with the goal of standardizing quality of care and reducing the number of diagnostic tests performed and inappropriate medication use. The ADAPTE methodology was followed, and the recommendations were approved utilizing the Delphi strategy. The executive committee carried out the review of the guidelines, position papers, and international reviews that met the a priori quality criteria and possible applicability in a local context. The recommendations were taken from those sources and adapted, after which they were approved by the working group. The consensus consists of 25 statements and their supporting information on the diagnosis and treatment of GER and GERD in infants. The adapted document is the first systematic effort to provide an adequate consensus for use in Mexico, proposing a practical approach to and management of GER and GERD for healthcare providers.

Foreign body ingestion and associated factors in pediatric patients at a tertiary care center.

INTRODUCTION AND AIMS: Foreign body (FB) ingestion is a common problem in children under 5 years of age and is one of the main indications for endoscopy. The aim of the present study was to describe the clinical, radiographic, and endoscopic characteristics of patients with FB ingestion, as well as the factors associated with the anatomic location and the type of object ingested. MATERIALS AND METHODS: An analytic cross-sectional study was conducted on all patients with FB ingestion seen at the gastroenterology service from January 2013 to December 2018. The data were analyzed using the SPSS program, obtaining frequencies, percentages, medians, and interquartile ranges. Associations were assessed through the chi-square test. RESULTS: Eighty-five patients (52 males and 33 females) were included, with a median age of 4 years. The most common symptom was vomiting (29.4%). Two radiographic projections were carried out in 72.9% of the cases and the stomach was the site where the FB was most frequently visualized (32.9%). The objects most commonly ingested were coins (36%), with esophageal location (p<0.05), as well as objects with a diameter larger than 2cm (p<0.05). An endoscopic procedure was performed on 76 patients (89.4%) for FB extraction, with findings of erythema (28.9%), erosion (48.6%), ulcer (10.5%) and perforation (1.3%). CONCLUSIONS: Numerous factors should be taken into account in the approach to FB ingestion in pediatric patients, including type and size of the FB, time interval from ingestion to hospital arrival, and patient clinical status and age.

Esophagogastric junction outflow obstruction in the differential diagnosis of post-fundoplication dysphagia in children.

INTRODUCTION AND AIMS: Post-fundoplication dysphagia is resolved with no therapeutic intervention in the majority of cases but it can persist in 5.3% of children that undergo the procedure. Among the differential diagnoses, esophagogastric junction outflow obstruction (EGJOO) is a disorder that should be suspected if there is a persistence of dysphagia. The aim of our study was to describe the clinical characteristics, treatment, and follow-up in a case series of patients diagnosed with post-fundoplication EGJOO. MATERIALS AND METHODS: The clinical records of patients diagnosed with EGJOO at a tertiary care hospital within the time frame of September 2015 to September 2019 were reviewed, with respect to manometry, etiology, treatment, and clinical course of the disease. RESULTS: Of the 213 high-resolution esophageal manometries performed, 4 patients met the criteria for post-fundoplication EGJOO. The primary symptom was dysphagia, presenting 15 days after the procedure. Esophageal dilations were carried out on all the patients but with no improvement. Symptoms related to the condition resolved spontaneously in three of the four patients. CONCLUSION: The management of children with post-fundoplication EGJOO continues to be a challenge. Even though more than half of the cases resolve with no intervention, optimum management of the motility disorder is still limited, given the scant experience with the condition in the pediatric population.

Anorectal manometry in children with retentive fecal incontinence: What parameters should we evaluate? / Manometría anorrectal en niños con incontinencia fecal retentiva: ¿Qué parámetros debemos evaluar?

INTRODUCTION: Children with functional constipation frequently present with alterations in rectal compliance and the urge-to-defecate sensation that can be evaluated through anorectal manometry (ARM). In the present study, we evaluated the usefulness of the parameters obtained through ARM in children with retentive fecal incontinence (RFI). MATERIALS AND METHODS: Children with functional constipation, aged 4 to 17years, that underwent ARM were included in the study. RESULTS: Of the 35 children evaluated, 21 presented with functional constipation and 14 had functional constipation and RFI. The children with both constipation and RFI tolerated greater volumes of air insufflation for triggering the urge to defecate and reaching maximum tolerance of pain, compared with the children that did not have RFI. We identified the cutoff point of 135ml of air as the maximum tolerance sensation for distinguishing children with RFI. CONCLUSIONS: Maximum tolerance of pain was the most useful parameter for evaluating RFI in children with functional constipation.

The Mexican consensus on probiotics in gastroenterology. / Consenso mexicano sobre probióticos en gastroenterología.

INTRODUCTION: Probiotics are frequently prescribed in clinical practice. Their efficacy in treating gastrointestinal disorders is supported by a significant number of clinical trials. However, the correct prescription of these agents is hampered due to a lack of knowledge of the scientific evidence and to the different presentations and microbial compositions of the probiotics that are currently available. AIM: To provide the clinician with a consensus review of probiotics and recommendations for their use in gastroenterology. MATERIALS AND METHODS: Controlled clinical trials, meta-analyses, and systematic reviews published up to 2015 were selected, using the MESH terms: probiotics, gastrointestinal diseases, humans, adults, AND children. The Delphi method was employed. Eighteen gastroenterologists treating adult patients and 14 pediatric gastroenterologists formulated statements that were voted on until agreement>70% was reached. The level of evidence based on the GRADE system was evaluated for each statement. RESULTS AND CONCLUSIONS: Eleven statements on the general concepts of probiotics and 27 statements on the use of probiotics in gastrointestinal diseases in both adults and children were formulated. The consensus group recommends the use of probiotics under the following clinical conditions: the prevention of diarrhea associated with antibiotics, the treatment of acute infectious diarrhea, the prevention of Clostridium difficile infection and necrotizing enterocolitis, the reduction of adverse events from Helicobacter pylori eradication therapy, relief from irritable bowel syndrome symptoms, the treatment of functional constipation in the adult, and the induction and maintenance of remission in patients with ulcerative colitis and pouchitis, and the treatment of covert and overt hepatic encephalopathy.

Modulation of the transient outward current (Ito) in rat cardiac myocytes and human Kv4.3 channels by mefloquine.

The antimalarial drug mefloquine, is known to be a potassium channel blocker, although its mechanism of action has not being elucidated and its effects on the transient outward current (Ito) and the molecular correlate, the Kv4.3 channel has not being studied. Here, we describe the mefloquine-induced inhibition of the rat ventricular Ito and of CHO cells co-transfected with human Kv4.3 and its accessory subunit hKChIP2C by whole-cell voltage-clamp. Mefloquine inhibited rat Ito and hKv4.3+KChIP2C currents in a concentration-dependent manner with a limited voltage dependence and similar potencies (IC50=8.9µM and 10.5µM for cardiac myocytes and Kv4.3 channels, respectively). In addition, mefloquine did not affect the activation of either current but significantly modified the hKv4.3 steady-state inactivation and recovery from inactivation. The effects of this drug was compared with that of 4-aminopyridine (4-AP), a well-known potassium channel blocker and its binding site does not seem to overlap with that of 4-AP.

Histopathologic findings in children diagnosed with cow's milk protein allergy.

BACKGROUND: Cow's milk protein allergy is the most common cause of food allergy. The challenge test, either open or doubled-blind with a placebo control, is regarded as the criterion standard. Endoscopy and histologic findings are considered a method that can aid in the diagnosis of this entity. AIMS: The aim of this study was to describe the histopathologic findings in children suspected of cow's milk protein allergy that were seen at our hospital. MATERIAL AND METHODS: A descriptive, observational study was conducted on 116 children clinically suspected of presenting with cow's milk protein allergy that were seen at the Department of Gastroenterology and Nutrition of the Instituto Nacional de Pediatría. Upper endoscopy and rectosigmoidoscopy with biopsies were performed and the findings were described. RESULTS: Of the 116 patients, 64 (55.17%) were girls and 52 (44.83%) were boys. The rectum was the site with the greatest presence of eosinophils per field in both groups, followed by the duodenum. In general, more than 15 eosinophils were found in 46% of the patients. CONCLUSIONS: Between 40 and 45% of the cases had the histologic criterion of more than 15 to 20 eosinophils per field and the rectosigmoid colon was the most affected site. Therefore, panendoscopy and rectosigmoidoscopy with biopsy and eosinophil count are suggested.

Perinatal factors associated with the development of cow's milk protein allergy.

UNLABELLED: The prevalence of cow's milk protein allergy (CMPA) has increased in recent years, and is associated with antimicrobial use during the perinatal period, prematurity, the type of childbirth, and the decrease in breastfeeding. The aim of this study was to analyze whether there is any association between these factors and the development of CMPA. MATERIAL AND METHODS: A retrospective, comparative, cross-sectional, observational study was conducted by reviewing the case records of 101 children diagnosed with CMPA and seen at the Department of Gastroenterology and Nutrition of the Instituto Nacional de Pediatría within the time frame of January 2012 and August 2013. The following variables were included: age, sex, weeks of gestation, history of maternal infection and antimicrobial use during the pregnancy, type of delivery, and feeding with human milk, and its duration. Likewise, the case records of 90 children were reviewed as a control group on not having CMPA or any other allergy. The chi-square test was used for proportions, and the Mann-Whitney U test was used for comparing means in the statistical analysis. RESULTS: The factors associated with CMPA were the use of antimicrobials during gestation and breastfeeding duration in months. Both factors were statistically significant (P<.001). No association was found between CMPA and gestational age or type of delivery. CONCLUSIONS: The statistically significant associated factors were breastfeeding duration and the use of antimicrobials during the gestational stage. These results underline the necessity for prospective studies.

Clinical, radiologic, and endoscopic characteristics upon diagnosis of patients with prehepatic portal hypertension at the Instituto Nacional de Pediatría from 2001 to 2011.

BACKGROUND: Prehepatic portal hypertension in children can be asymptomatic for many years. Once diagnosed, the therapeutic measures (pharmacologic, endoscopic, and surgical) are conditioned by the specific characteristics of each patient. In Mexico, there are no recorded data on the incidence of the disease and patient characteristics. AIMS: To determine the main clinical, radiologic, and endoscopic characteristics upon diagnosis of these patients at the Instituto Nacional de Pediatría within the time frame of January 2001 and December 2011. METHODS: A cross-sectional, retrolective, descriptive, and observational study was conducted in which all the medical records of the patients with portal hypertension diagnosis were reviewed. RESULTS: There was a greater prevalence of prehepatic etiology (32/52) (61.5%) in the portal hypertension cases reviewed. Males (62.5%) predominated and 11 of the 32 patients were under 4 years of age. The primary reason for medical consultation was upper digestive tract bleeding with anemia (71.9%) and the main pathology was cavernomatous degeneration of the portal vein (65.6%). Splenoportography was carried out on 17 of the 32 patients. A total of 65.5% of the patients received the combination therapy of propranolol and a proton pump inhibitor. Initial endoscopy revealed esophageal varices in 96.9% of the patients, 12 of whom presented with gastroesophageal varices. Congestive gastropathy was found in 75% of the patients. The varices were ligated in 8 cases, sclerotherapy for esophageal varices was carried out in 5 cases (15.6%), and sclerotherapy for gastric varices was performed in 2 patients. Seventeen patients (53.1%) underwent portosystemic diversion: 10 of the procedures employed a mesocaval shunt and 7 a splenorenal shunt. Nine patients (28.1%) underwent total splenectomy. CONCLUSIONS: The primary cause of the disease was cavernomatous degeneration of the portal vein; it was predominant in males and the first symptom was variceal bleeding.

[24-h intraesophageal pH determination in children allergic to cow's milk protein at a tertiary care hospital]. / Determinación de pH intraesofágico de 24 h en niños con alergia a las proteínas de la leche de vaca en un hospital de tercer nivel.

BACKGROUND: Cow's milk protein allergy (CMPA) is being seen more frequently on a daily basis in pediatric consultations. It shares symptoms with gastroesophageal reflux (GER), which can complicate the differential diagnosis. AIMS: To attempt to corroborate the presence of acid GER in children with CMPA, as well as to find a characteristic profile through the 24-hour pH monitoring study in children with GER and CMPA METHODS: The intraesophageal pH monitoring studies performed on 47 children with CMPA were reviewed. The measurements in all the studies were carried out within a 24-hour period using Digitrapper® equipment with a multi-use GeroFlex® catheter, after calibration with pH 7 and pH 1 buffer solutions. RESULTS: Of the 47 children, 23 were boys (32.4%) and 24 were girls (33.8%) and the mean age was 5±3.7 years. Fourteen of the 47 children (29%) presented with GER, according to the result of the 24-hour intraesophageal measurement. Only 2 of the 47 patients studied fit the phasic profile. CONCLUSIONS: The findings show the existing relation between the two pathologies. Nevertheless, it is important to determine the presence of non-acid or weak acid reflux, because their existence can increase this association.

[Primary intestinal lymphangiectasia: twenty years of experience at a Mexican tertiary care hospital]. / Linfangiectasia intestinal primaria: 20 años de experiencia en el Instituto Nacional de Pediatría.

BACKGROUND: Primary intestinal lymphangiectasia is a rare congenital disease described by Waldmann in 1961 that is a consequence of obstruction of the lymphatic drainage of the small bowel with secondary lymph vessel dilation. This distorts the architecture of the villi and causes a leakage of lymph into the intestinal lumen, resulting in protein-losing enteropathy and malabsorption. AIM: To describe the clinical, biochemical, radiologic, endoscopic, and histologic characteristics in children with primary intestinal lymphangiectasia. METHOD: A retrospective observational, descriptive, cross-sectional study was conducted that reviewed the case records of children diagnosed with primary intestinal lymphangiectasia that were seen at the Department of Gastroenterology and Nutrition of the Instituto Nacional de Pediatría within the time frame of January 1, 1992 to September 30, 2012. RESULTS: Four patients were found that presented with primary intestinal lymphangiectasia. Three of them had been diagnosed before 3 years of age. All the patients presented with chronic diarrhea, edema, lymphopenia, hypocalcemia, and hypogammaglobulinemia, and 3 patients presented with hypocholesterolemia. Bowel transit time, endoscopy, and intestinal biopsies were characteristic of this pathology. CONCLUSIONS: Intestinal lymphangiectasia should be suspected when there is a clinical picture of chronic diarrhea and protein-losing enteropathy accompanied with edema at any level, as well as hypoalbuminemia, hypocalcemia, lymphopenia, hypogammaglobulinemia, and hypocholesterolemia, which are the main biochemical findings of this pathology. All children presenting with intestinal lymphangiectasia should undergo an upper gastrointestinal series with bowel transit time and endoscopy with biopsies taken at the level of the duodenum. Treatment includes diet and the periodic administration of albumin and gamma globulin.

L-type calcium channel activity regulates sodium channel levels in rat pituitary GH3 cells.

1. The effects of chronic pharmacological modulation of L-type Ca2+ channel activity on the cell surface expression of Na+ channels were examined in GH3 cells. 2. Prolonged inhibition (4-5 days) of L-channels with nimodipine caused a 50-60 % decrease in the peak amplitude of whole-cell Na+ currents recorded with the patch-clamp technique. On the contrary, prolonged exposure to the L-channel agonist Bay K 8644 induced an approximately 2.5-fold increase in peak Na+ current. In both cases, there were only minor changes in cell capacitance and no significant changes in Na+ channel gating properties. 3. Measurements of the specific binding of radiolabelled saxitoxin to intact cells showed that nimodipine treatment reduced the number of cell surface Na+ channels, whereas treatment with Bay K 8664 produced the opposite effect. The dual regulation of Na+ channel abundance explained the mentioned changes in Na+ current amplitude. 4. Plasma membrane Na+ channels had a half-life of approximately 17 h both in control cells and in cells treated with Bay K 8644, as estimated from the rate of decay of peak Na+ current after inhibition of protein synthesis with cycloheximide. Actinomycin D, an inhibitor of gene transcription, and also cycloheximide, occluded the stimulatory effect of Bay K 8644 on Na+ current density when measured over a 24 h period. 5. These findings indicate that the entry of Ca2+ through L-type channels influences in a positive way the number of functional Na+ channels in GH3 cells, and suggest that Ca2+ influx stimulates either Na+ channel gene expression or the expression of a regulatory protein that promotes translocation of pre-assembled Na+ channels into the plasma membrane.