A Delphi Analysis to Reach Consensus on Preoperative Care in Infants with Hypertrophic Pyloric Stenosis.

INTRODUCTION: Infantile hypertrophic pyloric stenosis (IHPS) is a common gastrointestinal condition that can lead to metabolic alkalosis and, if uncorrected, to respiratory complications. A standardized approach to correct metabolic derangements and dehydration may reduce time until pyloromyotomy while preventing potential respiratory complications. Such an evidence-based policy regarding preoperative care is absent. We aim to formulate a recommendation about preoperative care for infants with IHPS using the Delphi technique. MATERIALS AND METHODS: The RAND/UCLA appropriateness method was used to reach international consensus in a panel of pediatric surgeons, pediatric anesthetists, and pediatricians. Statements on type and frequency of blood sampling, required serum concentrations before pyloromyotomy and intravenous fluid therapy, were rated online using a 9-point Likert scale. Consensus was present if the panel rated the statement appropriate/obligatory (panel median: 7-9) or inappropriate/unnecessary (panel median: 1-3) without disagreement according to the interpercentile range adjusted for symmetry formula. RESULTS: Thirty-three and twenty-nine panel members completed the first and second round, respectively. Consensus was reached in 54/74 statements (73%). The panel recommended the following laboratory tests and corresponding cutoff values prior to pyloromyotomy: pH ≤7.45, base excess ≤3.5, bicarbonate <26 mmol/L, sodium ≥132 mmol/L, potassium ≥3.5 mmol/L, chloride ≥100 mmol/L, and glucose ≥4.0 mmol/L. Isotonic crystalloid with 5% dextrose and 10 to 20 mEq/L potassium should be used for fluid resuscitation. CONCLUSION: Consensus is reached in an expert panel about assessment of metabolic derangements at admission, cutoff serum concentrations to be achieved prior to pyloromyotomy, and appropriate intravenous fluid regime for the correction of dehydration and metabolic derangements in infants with IHPS.

Epidemiological and clinical characteristics of 304 patients with infantile hypertrophic pyloric stenosis in Anhui Province of East China, 2012-2015.

OBJECTIVE: To analyze the clinical and epidemiological features of patients with infantile hypertrophic pyloric stenosis (IHPS) so as to provide scientific evidence for diagnosis and prevention of IHPS. METHODS: We performed a retrospective study of infants with IHPS diagnosed from 2012 to 2015 at Anhui Provincial Children's Hospital. Demographic characteristics and clinical data were collected. RESULTS: Three hundred four patients (264 males and 40 females) were studied, of which 94.7% were full term and 75.7% were bottle fed or mixed fed; 16.8% of the patients had other congenital malformations in combination with IHPS. The proportion of IHPS cases with hyponatremia, hypokalemia, and hypochloremia was 18.4%, 12.5%, and 53.9%. A negative correlation was found between duration of disease and serum electrolytes. The mean pyloric muscle thickness, pyloric length, and diameter were 4.8 ± 0.7 mm, 19.4 ± 2.5 mm, and 13.3 ± 1.8 mm, respectively. There were significant differences in muscle thickness, pyloric length, and diameter between short (≤14 d) and long (>14 d) durations of disease. All patients underwent pyloromyotomy, and postoperative recovery was good. CONCLUSIONS: IHPS occurs mainly in male, full-term, bottle-fed or mixed-fed infants. Patients with long duration of disease were more likely to develop electrolyte disorder and thicker muscle layer. More attention should be paid to early discovery and diagnosis, which will help to improve the curative effect and prognosis of IHPS.

Corrected to uncorrected? The metabolic conundrum of hypertrophic pyloric stenosis.

OBJECTIVES: The purpose of this study was to evaluate factors associated with repeat blood testing after establishment of normal metabolic parameters and factors associated with reversal of metabolic correction back an uncorrected form in preoperative management of infants with Hypertrophic Pyloric Stenosis (HSP). METHODS: A retrospective review of infants with HSP undergoing repeat serum chemistries after already having normal labs were identified. Variables associated with repeating normal bloodwork and reversion of normal to abnormal labs were identified. Associations between reversion to abnormal and ordering of repeat labs were determined. RESULTS: 255 cases were studied with a median of 2 lab tests drawn per patient (range 1-9). Of 142 serum chemistry tests repeated after a normal test, 27% became abnormal, most commonly hyperkalemia. 61% of these went to surgery. No variables were associated with a normal test becoming abnormal. However, a time lapse of >12h was associated with the reordering of bloodwork despite it already being normal. CONCLUSIONS: There is little evidence to support need for repeat serum chemistry testing in cases of HPS once normality has been established. Development of clinical pathways to reduce the use of unnecessary serum testing may improve efficiency of patient care and limit unnecessary resource utilization. LEVEL OF EVIDENCE: Retrospective Case control: 3b.

Health disparities in infants with hypertrophic pyloric stenosis.

BACKGROUND: This study investigates whether health disparities exist in infants with hypertrophic pyloric stenosis (HPS), to identify factors affecting definitive treatment, and if more morbidity occurs. METHODS: A 6-year retrospective analysis was performed on infants with HPS. Analysis of variance was used to evaluate the impact of socioeconomic factors on disease severity and hospitalization. General linear models were used to assess the impact of risk factors on the outcomes. RESULTS: There were a total of 584 infants. African-American's had lower serum chloride (P < .001), higher bicarbonate (P = .001), and sodium levels (P = .006), adding to longer hospitalization than whites (P = .03). Uninsured infants had lower sodium and chloride (P < .001) and higher bicarbonate (P < .001), resulting in a longer time to operation (P = .05) than privately insured infants. In multivariable analyses, African-American's were associated with chloride (P = .002) and higher bicarbonate (P = .009), and uninsured status remained significantly associated with all electrolyte abnormalities. CONCLUSIONS: African-American and poorly insured infants with HPS had greater risk of metabolic derangements. This required more time to correct dehydration and electrolytes, adding to longer hospitalizations.

Plasma lipids, genetic variants near APOA1, and the risk of infantile hypertrophic pyloric stenosis.

IMPORTANCE: Infantile hypertrophic pyloric stenosis (IHPS) is a serious condition in which hypertrophy of the pyloric sphincter muscle layer leads to gastric outlet obstruction. Infantile hypertrophic pyloric stenosis shows strong familial aggregation and heritability, but knowledge about specific genetic risk variants is limited. OBJECTIVES: To search the genome comprehensively for genetic associations with IHPS and validate findings in 3 independent sample sets. DESIGN, SETTING, AND PARTICIPANTS: During stage 1, we used reference data from the 1000 Genomes Project for imputation into a genome-wide data set of 1001 Danish surgery-confirmed samples (cases diagnosed 1987-2008) and 2371 disease-free controls. In stage 2, the 5 most significantly associated loci were tested in independent case-control sample sets from Denmark (cases diagnosed 1983-2010), Sweden (cases diagnosed 1958-2011), and the United States (cases diagnosed 1998-2005), with a total of 1663 cases and 2315 controls. MAIN OUTCOMES AND MEASURES: Association of genetic variation with the presence of infantile hypertrophic pyloric stenosis. RESULTS: We found a new genome-wide significant locus for IHPS at chromosome 11q23.3. The single-nucleotide polymorphism (SNP) with the lowest P value at the locus, rs12721025 (odds ratio [OR], 1.59; 95% CI, 1.38-1.83; P = 1.9 × 10(-10)), is located 301 bases downstream of the apolipoprotein A-I (APOA1) gene and is correlated (r2 between 0.46 and 0.80) with SNPs previously found to be associated with levels of circulating cholesterol. For these SNPs, the cholesterol-lowering allele consistently was associated with increased risk of IHPS. CONCLUSIONS AND RELEVANCE: This study identified a new genome-wide significant locus for IHPS. Characteristics of this locus suggest the possibility of an inverse relationship between levels of circulating cholesterol in neonates and IHPS risk, which warrants further investigation.

Electrolyte profile of pediatric patients with hypertrophic pyloric stenosis.

OBJECTIVES: Recent investigations have demonstrated that the classic hypochloremic, hypokalemic, metabolic alkalosis of hypertrophic pyloric stenosis (HPS) is not a common finding.Some have suggested a trend over time, but none has investigated factors contributing to laboratory derangement, such as duration of vomiting or patient age at presentation. We sought to determine the proportion of patients with HPS with normal and abnormal laboratory findings as a function of year of presentation, duration of vomiting, and patient age. METHODS: This is a retrospective chart review of 205 patients younger than 6 months with operative diagnosis of HPS at a tertiary, regional pediatric center from 2000 to 2009. We examined the acid-base status and electrolyte levels (serum bicarbonate [CO2], serum potassium [K], and serum chloride [Cl]) at the time of the index visit to determine the proportion of normal, high, and low values for each as a function of year of presentation, duration of vomiting, and patient age. RESULTS: The proportion of HPS cases with normal CO2 was 62%; low serum CO2, 20%; and high CO2, 18%. The proportion with normal serum K was 57%; low K, 8%; and high K, 35%. The proportion with normal Cl was 69%; low Cl, 25%; and high Cl, 6%. Logistic regression analysis demonstrated that the prevalence of metabolic alkalosis increased across the decade, whereas the prevalence of metabolic acidosis decreased and that advancing age was associated with the presence of alkalosis. CONCLUSIONS: We observed that normal laboratory values are the most common finding in HPS and that metabolic alkalosis was found more commonly in the latter part of the decade and in older infants.

No association between the SNPs (rs56134796; rs3824934; rs41302375) in the TRPC6 gene promoter and infantile hypertrophic pyloric stenosis in Chinese people.

PURPOSE: Our aim is to verify the association of three Single nucleotide polymorphisms (SNPs) (-218A/G, -254C/G, -361A/T) in the promoter of TRPC6 in 168 sporadic cases with infantile hypertrophic pyloric stenosis (IHPS) and 164 controls in Chinese people. METHODS: All participants were genotyped using polymerase chain reaction and direct sequencing. And the χ(2) value was calculated. A value of P less than 0.05 was considered statistically significant. We also got the P value of Hardy-Weinberg equilibrium test, and the value of P greater than 0.05 was assumed to be at Hardy-Weinberg equilibrium in this population. RESULTS: The results tell us that there are no significant differences in the allele and genotype frequencies of all these three SNPs between the case and the control groups (P > 0.05). CONCLUSION: These three TRPC6 SNPs have no association with the IHPS in Chinese people. However, we cannot deny that TRPC6 would be a susceptible gene with IHPS in Chinese people. May be other SNPs in TRPC6 would have some association with the IHPS in Chinese people. But in this study our results may be due to the fact that these SNPs are not the functional SNPs for the development of IHPS in Chinese people.

Low plasma nitrite in infantile hypertrophic pyloric stenosis patients.

There is now substantial evidence that reduced expression of neuronal nitric oxide synthase (nNOS) is implicated in the pathogenesis of infantile hypertrophic pyloric stenosis (IHPS). This study aimed to investigate the role of plasma nitric oxide (NO) in patients with IHPS. Blood and pylorous biopsies of 13 IHPS patients were examined. The control group consisted of 19 age-matched healthy infants and 22 age-matched acute gastroenteritis patients. Plasma nitrite (NO(2-)) and nitrate (NO(3-)) levels were detected with an NO analyzer. Pylorus biopsies of 13 IHPS patients were examined for nitric oxide synthase isoform expression. Plasma nitrite levels in the 13 IHPS patients were significantly lower than in the age-matched healthy controls (0.97 +/- 0.19 vs. 3.53 +/- 0.79 microM; P < 0.001) and the acute gastroenteritis controls (0.97 +/- 0.19 vs.1.39 +/- 0.45 microM; P = 0.006). Decreased expression of nNOS in the nerve fibers of the pylorus circular muscle was found in the 13 IHPS patients. The decreased plasma nitrite levels rose to the normal range (3.27 +/- 0.77 M) after pyloromyotomy. There was no significant correlation between plasma nitrite levels and muscle wall thickness in IHPS patients. We conclude that NO is implicated in the occurrence of IHPS and the plasma nitrite level is valuable for the diagnosis of IHPS.