Diagnostic aids in the differentiation of pyloric stenosis from severe gastroesophageal reflux during early infancy: the utility of serum bicarbonate and serum chloride

Advances in infantile hypertrophic pyloric stenosis

Infantile hypertrophic pyloric stenosis (IHPS) is a common condition in infancy, characterized by an acquired narrowing of the pylorus, which requires surgery. These infants usually present with projectile, nonbilious vomiting, with a palpable 'olive' in the abdomen and sometimes a 'peristaltic wave' after being fed with formula or breast milk. Although IHPS is a common disorder, its etiology is largely unknown. Surgical intervention is the standard treatment, preoperative preparation, however is essential to optimal outcome. In this review, the latest advances in IHPS regarding epidemiology, etiology, diagnostics and treatment will be discussed.

The ins and outs of pyloromyotomy: what we have learned in 35 years

PURPOSE/BACKGROUND

The aim of the study is to evaluate a large series of infantile hypertrophic pyloric stenosis (IHPS) patients treated by one pediatric surgeon focusing on their diagnostic difficulties and complications.

METHODS

From July 1969 to December 2003 (inclusive), the charts of 791 infants with IHPS were retrospectively reviewed.

RESULTS

There were 647 (82%) males and 144 (18%) females; mean age was 38 days, median 51 (range 7 days-10 months). When ultrasonography (US) was routinely used (1990), the age at diagnosis decreased to <40 days. The mean weight before and after routine US was 3.2 kg, median 3 (range 1.5-6). Twenty-five (3.1%) were premature at diagnosis, mean age 49 days, median 56, (range 1-3 months) and mean weight 2.5 kg, median 2.3 (range 1.5-3.2). Eighty-one (10%) had a positive family history. Forty-four (5%) were non-Caucasians. Seventy-five (9 %) had other medical conditions, anomalies and/or associated findings. Sixty (7%) patients had abnormal preoperative electrolytes. Ten (1.2%) pylorics occurred after newborn operations. Of the entire total (791) who were treated, there were 13 (1.7%) not operated on. All operations were done open initially through one of two right upper quadrant incisions, and then through an upper midline incision under general endotracheal anesthesia; 14 (1.7 %) had concomitant procedures. Prophylactic antibiotics (from 1982) decreased the wound infection rate to 3.9%. There were a total of 87 (10%) complications which included 9 (1.1%) intraoperative, (including mistaken diagnoses) 78 (9%) postoperative: 59 (2%) early (<1 month) and 19 (2.4%) late (>1 month). The 13 (1.6%) postoperative transfers (12 from non-pediatric surgeons) had 16 (18%) complications (including 1 death); five (33%) requiring reoperation (4 incomplete, 1 perforation). There were two deaths.

CONCLUSIONS

IHPS should be considered in any vomiting infant. US allows earlier diagnosis. Serious complications are uncommon and avoidable, but recognizable and easily corrected. Higher surgeon volume of pyloromyotomies (>14 per year) is associated with fewer complications.

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.

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.

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.

Abdominal pain in children

Abdominal pain and gastrointestinal symptoms such as vomiting or diarrhea are common chief complaints in young children who present in emergency departments. It is the emergency physician's role to differentiate between a self-limited process such as viral gastroenteritis or constipation and more life-threatening surgical emergencies. Considering the difficulties inherent in the pediatric examination, it is not surprising that appendicitis, intussusception, and malrotation with volvulus continue to be among the most elusive diagnoses. This article reviews both the self-limited and more life-threatening gastrointestinal conditions that may present in the emergency department.

Evaluation of a Bayesian decision network for diagnosing pyloric stenosis

PURPOSE

Most infants undergoing an ultrasound to rule out pyloric stenosis will have a negative study, suggesting the low accuracy of clinical assessment. The purpose of this study was to evaluate the feasibility of using a Bayesian network to improve the accuracy of diagnosing pyloric stenosis.

METHODS

Records of 118 infants undergoing an ultrasound to rule out pyloric stenosis were reviewed. Data from 88 (75%) infants were used to train a Bayesian decision network that predicted the probability of pyloric stenosis using risk factors, signs, and symptoms of the disease. The emergency department records of the remaining 28 (25%) infants were used to test the network. Two groups of pediatric surgeons and pediatric emergency medicine physicians were asked to predict the probability of pyloric stenosis in the testing set: (1) physicians using the network and (2) physicians using only emergency department records. Accuracy was evaluated using area under the ROC curve (discrimination) and Hosmer-Lemeshow (H-L) c-statistic (calibration).

RESULTS

Physicians using the Bayesian decision network better predicted the probability of pyloric stenosis among infants in the testing set than those not using the network (ROC 0.973 vs 0.882; H-L c-statistic 3.9 [P > .05] vs 24.3 [P < .05]). Physicians using the network would have ordered 22% fewer ultrasounds and missed no cases of pyloric stenosis.

CONCLUSIONS

The use of a Bayesian decision network may improve the accuracy of physicians diagnosing infants with possible pyloric stenosis. Use of this decision tool may safely reduce the need for imaging among infants with suspected pyloric stenosis.

Abdominal surgical emergencies in infants and young children

Surgical emergencies can be missed easily in children, who are not always able to volunteer relevant information. Awareness of the entities discussed in this review might help the EP uncover subtle clues to early diagnoses that might not be initially apparent. Ill-appearing children who have abdominal pain and vomiting should be considered to have ischemic or necrotic bowel until proven otherwise. Possible diagnoses include volvulus, intussusception, and necrotizing enterocolitis. Bilious vomiting, especially in a young infant, should be considered to be an indication of a high bowel obstruction such as midgut volvulus, which warrants immediate surgical consultation. Significant rectal bleeding with abdominal pain can result from intussusception, volvulus, or an inflamed Meckel's diverticulum. Rectal bleeding with unstable vital signs can result from an upper GI bleed (eg, peptic ulcer disease). Painless rectal bleeding can result from a Meckel's diverticulum, polyps, arteriovenous malformation, or a tumor. Examination of the genitalia is imperative, especially in boys, to exclude the possibility of an incarcerated hernia or testicular torsion.

Common complaints in the first 30 days of life

Visits to the emergency department (ED) by neonates and their parents can cause anxiety for parents and the ED staff. Many of the presenting complaints are unique to the neonatal population, and an understanding of both common problems and true medical emergencies is paramount. This article discusses the complaints the EDs have seen more frequently as a result of earlier newborn discharges from hospitals.