The changing presentation of pyloric stenosis

Pediatric emergency medicine point-of-care ultrasound: summary of the evidence

The utility of point-of-care ultrasound is well supported by the medical literature. Consequently, pediatric emergency medicine providers have embraced this technology in everyday practice. Recently, the American Academy of Pediatrics published a policy statement endorsing the use of point-of-care ultrasound by pediatric emergency medicine providers.  To date, there is no standard guideline for the practice of point-of-care ultrasound for this specialty. This document serves as an initial step in the detailed "how to" and description of individual point-of-care ultrasound examinations.  Pediatric emergency medicine providers should refer to this paper as reference for published research, objectives for learners, and standardized reporting guidelines.

Association of prematurity with the development of infantile hypertrophic pyloric stenosis

BACKGROUND

Infantile hypertrophic pyloric stenosis (IHPS) has several known risk factors. The association between prematurity and IHPS and the timeline of presentation are poorly defined. Our aim was to evaluate the associations between IHPS and prematurity.

METHODS

We performed a retrospective cohort study of 1,074,236 children born between June 2001 and April 2012 in the US Military Health System. IHPS cases and gestational ages (GA) were identified using billing codes. Additional risk factors for IHPS were controlled for in a multivariable logistic regression model.

RESULTS

The incidence of IHPS was 2.99 per 1,000 in preterm infants and 2.25 per 1,000 in full term (relative risk (RR) = 1.33, 95% confidence interval (CI) 1.16-1.54). The adjusted odds ratio for prematurity was 1.26 (95% CI 1.08-1.46). The median (interquartile range (IQR)) chronological age at presentation was 40 d (30-56) in preterm infants vs. 33 d (26-45) in full term (P < 0.001). Median postmenstrual age at presentation was 42 wk in preterm infants (40-42) vs. 45 wk (44-46) in full term (P < 0.001).

CONCLUSION

Prematurity is associated with IHPS. Premature infants develop IHPS at a later chronological age, but earlier postmenstrual age, than term infants. Providers should have an increased concern for IHPS development in premature infants.

Infantile hypertrophic pyloric stenosis: does size really matter?

Pyloric stenosis is a common infantile disorder typically occurring between 2 weeks and 8 weeks of age. Presentation outside this range and in premature infants is uncommon and often atypical. We present three cases, a pair of premature twins and a 5.5-month-old infant with pyloric stenosis. We highlight that despite their difference in size and weight, ultrasound examination remains a reliable diagnostic tool. However, pyloric measurements should be interpreted in combination with the other dynamic features on ultrasound.

The clinical features of infantile hypertrophic pyloric stenosis in Chinese Han population: analysis from 1998 to 2010

Objective

To investigate clinical features of infantile hypertrophic pyloric stenosis (IHPS) in Chinese Han population.

Methods

Three hundred and sixteen hospitalized patients with IHPS from January 1998 to February 2010 were retrospectively reviewed, and data including patient's sex, onset age, other coexisting congenital defects, pyloric circular muscle thickness evaluated by ultrasonograph, serum electrolytes concentration, and results of arterial blood gas analysis on admission were collected. The patients were divided into two groups: the duration between first onset and admission less than or equal to 10 days (early onset group), and more than 10 days (late onset group). The results of arterial blood gas and serum electrolyte concentration were compared between the two groups.

Results

There were 271 males and 45 females in 316 patients; the onset age ranged between 1 and 351 (26.5±26.6) days. The birth weight ranged between 1.6 and 4.5 (3.23±0.44) kilograms; coexisting congenital defects were found in 65 cases (20.6%). Pyloric circular muscle thickness was 4–8 (5.4±1.0) millimetres (mm). For the early onset group, the rates of hypokalemia, hypochloraemia and hypercapnia were significantly lower than those in the late onset group (18.67% VS 50%, P<0.0001; 46.03% VS 71.01%, P = 0.003; 56.58% VS 83.44%, P = 2.17×10⁻⁵; respectively).

Conclusions

The symptom duration in Chinese Han population was longer than that in other populations. And as the prolongation of symptom duration, the incidence of acid-base imbalance increased significantly. Infants with persistent vomiting at the age of 3∼5 weeks after birth should be considered IHPS, and go to hospital as soon as possible in order to reduce the incidence of hypokalemia, hypochloraemia and hypercapnia, and avoid deterioration.

Is There a Relation Between Pyloric Muscle Thickness and Clinical and Laboratory Data in Infants with Hypertrophic Pyloric Stenosis?

Literature about the association between clinical and laboratory presentation and pyloric muscle thickness in infants with pyloric stenosis is lacking. The objective of this study is to examine the effect of pyloric muscle thickness on clinical and laboratory presentation in infants with pyloric stenosis. Thirty infants with hypertrophic pyloric stenosis presented at the Maternity and Children Hospital, Al-Madinah, Saudi Arabia, were included in this study analysis. Clinical and laboratory data of these infants were recorded. Statistical tests and univariate linear regression analyses were used as appropriate. P value was considered significant at a level ≤0.05. The mean age of the studied infant was 5.1 ± 2.6 weeks and mean weight was 3.4 ± 0.7 kg. Most of these infants were full-term (93.3 %), some presented to the hospital dehydrated (80 %), and some were lethargic (56.7 %). The mean pyloric muscle thickness among these infants showed statistically significant difference with regard to the studied clinical and laboratory data. A linear regression analyses also showed positive association between increasing pyloric muscle thickness and almost all studied clinical and laboratory data, with statistically significant difference observed for hyponatremia, hypochloremia, and high bicarbonates. The findings suggest that pyloric muscle thickness is a significant factor that determines the severity of clinical and laboratory presentation in infants with pyloric stenosis.

Evaluation of hypertrophic pyloric stenosis by pediatric emergency physician sonography

OBJECTIVES

The objective was to evaluate the accuracy of pediatric emergency physician (EP) sonography for infants with suspected hypertrophic pyloric stenosis (HPS).

METHODS

This was a prospective observational pilot study in an urban academic pediatric emergency department (PED). Patients were selected if the treating physician ordered an ultrasound (US) in the department of radiology for the evaluation of suspected HPS.

RESULTS

Sixty-seven patients were enrolled from August 2009 through April 2012. When identifying the pylorus, pediatric EPs correctly identified all 10 positive cases, with a sensitivity of 100% (95% confidence interval [CI] = 62% to 100%) and specificity of 100% (95% CI = 92% to 100%). There was no statistical difference between the measurements obtained by pediatric EPs and radiology staff for pyloric muscle width or length (p = 0.5 and p = 0.79, respectively).

CONCLUSIONS

Trained pediatric EPs can accurately assess the pylorus with US in the evaluation of HPS with good specificity.

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.

Infantile hypertrophic pyloric stenosis: has anything changed?

AIM

The study aims to review the contemporary presentation, diagnosis and treatment of children with infantile hypertrophic pyloric stenosis (IHPS) at an Australian paediatric tertiary centre.

METHODS

A retrospective case review of patients with IHPS presenting to our institution between January 2004 and December 2010 was performed. Results were compared with a previous study evaluating two earlier 6-year series of patients treated between January 1984 and November 1995.

RESULTS

Of 362 infants presenting over the current 7-year review, 84.8% were male. Mean age of admission fell from 5.9 weeks in the previous study to 5.4 weeks. An 'olive' was palpated on examination in 48%, visible peristalsis seen in 25% and 16% of patients presented with haematemesis. Diagnosis solely on clinical examination fell from 74% to 9% and was associated with a corresponding increase in use of ultrasound from 16% to 91%. The frequency of serum chloride values less than 85 mmol/L declined from 26% to 9%. A variety of open and minimally invasive surgical approaches were used with similar outcomes, although laparoscopic pyloromyotomy was associated with significantly higher rates of wound infection (χ(2) = 4.6, P = 0.03). The frequency of major complications remained low at 1%.

CONCLUSION

Contemporary patients with IHPS typically present earlier with a reduction in the incidence of metabolic derangement. Diagnosis based on clinical examination alone appears uncommon, with the majority of suspected cases confirmed by ultrasound. There was no clear difference in overall outcome based on the surgical approach used, although minor variations may reflect our institution's initial experience with laparoscopic pyloromyotomy.

A crying baby: not simply infant colic

Hypertrophic pyloric stenosis is a relatively common condition, but atypical presentations can present a diagnostic challenge. We describe the case of a 9-week-old Latin male infant who presented with a 2-day history of intermittent crying and poor feeding. He was suspected to have intussusception but was affected by and successfully treated for hypertrophic pyloric stenosis. Diagnostic tools of atypical HPS cases are discussed.

Bilious vomiting does not rule out infantile hypertrophic pyloric stenosis

OBJECTIVE

To describe the incidence of bilious vomiting in infants with infantile hypertrophic pyloric stenosis that presented to a pediatric emergency department.

METHODS

A retrospective medical record review included all infants who presented to our level 1 pediatric emergency department from January 1, 2005, through December 31, 2009, who were diagnosed intraoperatively with infantile hypertrophic pyloric stenosis. Emesis was determined to be bilious if the vomit was described as "green," "containing bile," or "bilious."

RESULTS

The authors identified 354 infants with infantile hypertrophic pyloric stenosis. The median age was 4 weeks 6 days (range = 11 days to 13 weeks). Bilious emesis was encountered in 1.4% (5/354; 95% confidence interval = 0.5% to 3.2%). The pyloric thickness measurements on ultrasound were significantly smaller in those with bilious emesis compared with those without bilious emesis (z score = 2.64; P = .014).

CONCLUSION

Bilious emesis was the presenting symptom in a small proportion of infants with infantile hypertrophic pyloric stenosis.

The changing clinical presentation of hypertrophic pyloric stenosis: the experience of a large, tertiary care pediatric hospital

The authors reviewed the clinical and laboratory data from cases of hypertrophic pyloric stenosis (HPS) diagnosed at their institution from 2006 to 2008. They assessed and compared presentation of patients with HPS over time at their institution. A total of 118 patients were included in this study. An "olive" was palpated in only 13.6% of cases. This is in contrast to older studies, where more than 50% of the patients were reported to have a palpable "olive" depending on when the study was conducted. In patients from this institution, hypochloremia was present in 23% and alkalosis in 14.4%, which are less frequent than the incidence of these abnormalities in older studies. There was a change in the additional "classical" symptoms, represented by the lower percentage of infants in whom an "olive" was palpated and the lower numbers of patients with severe electrolyte imbalances. The reason for this change appears to be the frequent use of ultrasound.

Early pyloric stenosis: a case control study

OBJECTIVE

Pyloric stenosis (PS) is rare in the first 2 weeks of life, often leading to delays in diagnosis and treatment. We conducted a case control study to delineate the characteristics of patients with early PS (EPS). In addition, we tested the hypothesis that patients with EPS present with a smaller pylorus than older patients.

METHODS

A database of all patients presenting with PS to a children's hospital over a 5-year period (2002-2006) was obtained. Each patient admitted during the first 2 weeks of life (subject) was matched to a patient admitted after 4 weeks of age (control), with the same gender, electrolyte status, and treating surgeon. A single pediatric radiologist, blinded to patient age, reviewed all available ultrasounds retrospectively. Demographic, clinical, diagnostic, therapeutic, and outcome data were compared.

RESULTS

During the study period, 278 pyloromyotomies were performed for PS. Sixteen patients (5.8%) presented with EPS between 2 and 14 days of life. EPS patients had a higher prevalence of positive family history (31 vs. 0%, P = 0.043), and breast milk feeding (75 vs. 31%, P = 0.045). Sonographic measurements showed a pylorus that was of significantly less length (17.1 +/- 0.6 vs. 20.5 +/- 0.9 mm, P = 0.006) and muscle thickness (3.5 +/- 0.2 vs. 4.9 +/- 0.2 mm, P < 0.001) in patients with EPS. Hospital stay was significantly longer for EPS patients (4.3 +/- 0.9 vs. 2.0 +/- 0.1 days, P = 0.19).

CONCLUSIONS

Babies presenting with EPS are more likely to be breast fed and to have a positive family history. EPS is associated with a longer hospital stay. Use of sonographic diagnostic measurements specific to this age group may prevent delays in diagnosis and treatment, and improve outcomes.

Does exclusive breastfeeding confer protection against infantile hypertrophic pyloric stenosis? A 30-year experience in Benin City, Nigeria

The incidence of infantile hypertrophic pyloric stenosis has steadily decreased in developing countries, and this study was designed to confirm this and establish any protection conferred by exclusive breastfeeding. A retrospective study was done between July 1978 and June 2008, at the University of Benin Teaching Hospital, Benin City, Nigeria. A total of 57 children aged between 2 and 6 weeks (mean 3.5 +/- 1.2 weeks) comprising of 49 males and 8 females with male female ratio 6.1 : 1 were treated. Following the introduction of exclusive breastfeeding in late 1980s and early 1990 s in Nigeria, a steady drop in incidence was noticed, with only five cases seen in the last decade and just one case seen in the past 5 years. All were babies who had artificial feeds, with none recorded among babies exclusively breastfed. This decrease in the incidence of infantile hypertrophic pyloric stenosis may have been due to exclusive breastfeeding.

Hypertrophic pyloric stenosis in newborns younger than 21 days: remodeling the path of surgical intervention

BACKGROUND

According to currently accepted diagnostic criteria, ultrasonography confirms hypertrophic pyloric stenosis (HPS) when the pyloric muscle thickness (MT) is greater than 4 mm and the pyloric channel length (CL) is greater than 15 mm. Hypertrophic pyloric stenosis frequently presents in newborns younger than 21 days; yet, the diagnostic criteria in this younger population remain poorly defined. We, therefore, sought to define the diagnostic criteria for HPS in newborns younger than 21 days.

METHODS

Ultrasonographic measures of pyloric MT and CL were obtained by retrospective chart review (2000-2006) at a single institution for all newborns (aged 10 days to 6 weeks) with an intraoperatively proven diagnosis of HPS. Demographic characteristics and ultrasonographic measurements were collected, and features differentiating younger (21 days or younger) from older newborns were assessed. Measures of pyloric MT and CL were analyzed in 7-day increments, and comparisons were made between newborns aged 21 days or less and newborns 22 to 42 days of age. Based upon these features, a set of ultrasonographic parameters to establish the diagnosis of HPS in younger patients was defined.

RESULTS

Three hundred fourteen newborns (83% male) underwent pyloromyotomy of whom 64% (n = 200) had a preoperative pyloric ultrasound. Sixty newborns (19%) were younger than 21 days, of whom 51 (85%) had preoperative ultrasonography. The ultrasound measurement of HPS was significantly decreased in younger vs older newborns: (MT, 3.7 +/- 0.65 vs 4.6 +/- 0.82 mm, P < .05; CL, 16.9 +/- 2.8 vs 18.2 +/- 3.4 mm, P < .05). Importantly, the mean ultrasound measurement for young newborns with HPS typically fell within the currently defined "normal" or "borderline" range. A linear relationship was determined to exist between pyloric MT and CL and patient age, suggesting the use of 3.5 mm as a "cutoff" in younger patients.

CONCLUSIONS

These findings suggest that current guidelines to diagnose HPS do not accurately diagnose HPS in children younger than 3 weeks, and these findings raise the need to evaluate the decision analysis algorithm using prospective studies.

Ultrasound evaluation of acute abdominal emergencies in infants and children

Ultrasound is extremely beneficial in the evaluation of acute pediatric abdominal disease, such as HPS, intussusception, and acute appendicitis. As techniques and equipment improve, its role in the evaluation of infants and children continues to increase.

Foveolar hyperplasia secondary to cow's milk protein hypersensitivity presenting with clinical features of pyloric stenosis

Pyloric stenosis is one of several causes of infantile nonbilious vomiting. A 7-week-old boy presenting with symptoms suggestive of this was found to have a prepyloric lobular mass causing near-complete gastric outlet obstruction. The histology showed localized hypertrophic gastropathy with hyperplasia and tortuosity of foveolar cells reminiscent of Menetrier changes. Postsurgical excision, the child continued vomiting until removal of bovine and soy proteins from his diet. The clinical presentation, pathology, and response to restrictive diet suggested cow's milk protein allergy as key. The literature describing infantile focal foveolar hyperplasia and Menetrier disease is reviewed, stressing the rarity of allergy as cause.

Treatment of infantile hypertrophic pyloric stenosis in a district general hospital: a review of 160 cases

BACKGROUND

Ramstedt's pyloromyotomy has long been the standard operation for the treatment of infantile hypertrophic pyloric stenosis. Controversy exists over whether this procedure can be performed safely in the district general hospital setting or whether it should be restricted to specialist pediatric units only.

METHODS

Retrospective analysis was performed on the medical records of a series of 160 infants treated by Ramstedt's pyloromyotomy by 2 surgeons in a district general hospital over 16 years.

RESULTS

There was no perioperative mortality. Oral feeding was achieved by 24 hours in 76% of infants, and there was persistent vomiting in only 3.8%. Wound discharge was encountered in 4.4% and confirmed wound infection in 1.3%. Wound dehiscence occurred in 1.9% of infants. Inadvertent mucosal perforation occurred in 19% of cases, although all cases were recognized and repaired at once with no apparent ill effects. These results are comparable with those reported from specialist pediatric units and from pediatric surgeons working within general surgical units.

CONCLUSIONS

Infantile hypertrophic pyloric stenosis can be treated safely in a district general hospital when care is provided by appropriately trained surgical, anesthetic, and pediatric staff.

Acute abdomen in infants of adolescent mothers: diagnostic challenges

Caring for children of adolescent parents presents unique challenges. Because adolescent parents may lack parenting skills and knowledge of medical terminology, symptoms of life-threatening illnesses may be misinterpreted. We present two cases of unexpected acute abdomen in young infants with adolescent mothers. The first case involves midgut volvulus, which was discovered during a routine newborn visit. The second case, involving pyloric stenosis, presented a clinical management challenge when the adolescent mother refused diagnostic studies.