Results of Lambling gastric juice analysis in infants with spastic hypertrophic pyloric stenosis (SHPS)

In 27 infants aged 20 to 65 days with clinically and roentgenologically proved hypertrophic pyloric stenosis gastric juice analyses were performed according to Lambling. Basic acid output and maximal acid output in these infants were significantly increased as compared to healthy infants of the same age group. The higher acid output in the hypertrophic pyloric stenosis group was due to higher volumes and a higher acidity of the gastric juices. Basic acid output and maximal acid output increased following pylorotomy. There is evidence, that hyperacidity in pylorus stenosis of infancy is primarily and not due to the pyloric constriction. There was a distinct correlation between the degree of metabolic alkalosis and diminished acid outputs. The findings support the thesis, that infantile hypertrophic stenosis is originated by an increased parietal cell mass. The increased acid secretion and the enhanced release of secretin and cholecystokinin are supposed to originate the hypertrophy of the pyloric muscle.     

Pre- and postoperative fluid management in infancy

The fluid and electrolyte management of the infant either before or following surgery is not difficult if the several principles are carefully followed: (1) Fluid requirements include maintenance therapy, correction of ongoing losses, and replacement of deficit losses. (2) Calculation for fluid requirements in the postoperative period will include maintenance therapy, correction of ongoing losses, and provision of fluid lost by internal shifts. (3) Maintenance needs for fluid in infants equals 100 to 120 mL/kg per 24 hours, and Na+ at 3 mEq/kg per 24 hours and K+ at 2 to 3 mEq/kg per 24 hours are needed. (4) Infants with pyloric stenosis should be anticipated to have hypokalemic, hypochloremic metabolic alkalosis, and dehydration. These electrolyte abnormalities should be corrected before surgery is performed. A pyloromyotomy is not an emergency procedure. (5) Ileostomy losses can equal 90 mEq/L of Na+ and up to 110 mEq/L of HCO3. Thus, adequate fluid replacement results in volume depletion and metabolic acidosis. (6) Children whose nutritional status is marginal and whose bowels cannot be used for nutrient absorption should receive their fluid and electrolyte needs as part of a total parenteral nutrition program.     

Is acid base determination an accurate predictor of pyloric stenosis?

OBJECTIVE: To determine if acid base status predicts which vomiting patients have pyloric stenosis. DESIGN: Retrospective chart review. SETTING: Tertiary paediatric hospital. METHODOLOGY: We compared the clinical and biochemical parameters of 100 patients with a discharge diagnosis of pyloric stenosis and 84 patients of a similar age who presented to the emergency department with vomiting and who had an acid base determination. Patients were included from January 1995 to January 1997. Clinical correlates consisted of age, duration of vomiting, weight loss, gestation, and family history of pyloric stenosis. Biochemical correlates were pH, bicarbonate, base excess (BE), chloride, potassium, and sodium. RESULTS: Independent variables of significance were pH, BE, chloride, bicarbonate, potassium, weight loss (all of which had a P value < 0.0001), and sex (P = 0.006). Each variable was placed in a logistic regression equation with pyloric stenosis being the dominant variable. Variables of significance were pH (P = 0.0001), BE (P = 0.0001), and chloride (P = 0.009). A model for predicting pyloric stenosis using these variables was then created with pH > 7.45, chloride < 98, and BE > +3, with a positive predictive value of 88%. CONCLUSION: Acid base determination is a useful screening tool when considering pyloric stenosis. This model now needs to be validated on a prospective series of patients with vomiting.     

Rapid correction of metabolic alkalosis in hypertrophic pyloric stenosis with intravenous cimetidine: preliminary results

Purpose  Pyloromyotomy has been the treatment of choice for hypertrophic pyloric stenosis (HPS) for the past century. In most HPS cases, there is mild metabolic alkalosis, which requires intravenous fluid resuscitation with 5% dextrose/normal saline for 1–2 days. However, in some cases, due to a delay in diagnosis, alkalosis becomes severe and a much longer resuscitation period (5–10 days) is required to normalize serum pH. Metabolic alkalosis of HPS results from excessive vomiting of hydrochloric acid; and therefore if its production is reduced, serum pH can be normalized faster. In this study, the use of intravenous cimetidine (CM) in a small number of infants with HPS is presented. Methods  Over a 28-month period, 32 HPS cases, including a sub-group of 17 infants (aged 7–9 weeks) with arterial pH >7.60, were admitted to a tertiary referral unit. Four infants in this sub-group were treated with standard resuscitation fluids for 4 days prior to intravenous CM, while 12 infants received CM immediately. Intravenous CM (10 mg/kg) was given at twice daily until arterial pH was less than 7.50. In one case, intravenous omeprazole at 0.1 mg/kg was given instead of CM. Results  In all 17 cases, CM treatment or omeprazole therapy (for 12–48 h) reduced pH to less than 7.50, thus allowing for Ramstedt pyloromyotomy the same day. These patients were allowed oral feeding on the following day and were discharged at 1–3 post-operative days. No complications due to CM (or omperazole) treatment were observed. Conclusion  Intravenous CM administration can rapidly normalize severe metabolic alkalosis in HPS patients. As a result, pyloromyotomy can be performed sooner reducing both hospital stay and costs.     

Intravenous atropine treatment in infantile hypertrophic pyloric stenosis

Aims: To assess the efficacy of a new regimen of intravenous atropine treatment for infantile hypertrophic pyloric stenosis (IHPS) with special reference to regression of pyloric hypertrophy. Methods: Atropine was given intravenously at a dose of 0.01 mg/kg six times a day before feeding in 19 patients with IHPS diagnosed from radiographic and ultrasonographic findings. When vomiting ceased and the infants were able to ingest 150 ml/kg/day formula after stepwise increases in feeding volume, they were given 0.02 mg/kg atropine six times a day orally and the dose was decreased stepwise. Results: Of the 19 infants, 17 (89%) ceased projectile vomiting after treatment with intravenous (median seven days) and subsequent oral (median 44 days) atropine administration. The remaining two infants required surgery. No significant complications were encountered. Ultrasonography showed a significant (p < 0.05) decrease in pyloric muscle thickness, but no significant shortening of the pyloric canal after completion of the atropine treatment. The patients exhibited failure to thrive at presentation, but were thriving at 6 months of age (p < 0.01). Conclusions: This atropine therapy resulted in satisfactory clinical recovery. Pyloric muscle thickness was significantly reduced.     

Intravenous atropine treatment in infantile hypertrophic pyloric stenosis.

AIMS: To assess the efficacy of a new regimen of intravenous atropine treatment for infantile hypertrophic pyloric stenosis (IHPS) with special reference to regression of pyloric hypertrophy. METHODS: Atropine was given intravenously at a dose of 0.01 mg/kg six times a day before feeding in 19 patients with IHPS diagnosed from radiographic and ultrasonographic findings. When vomiting ceased and the infants were able to ingest 150 ml/kg/day formula after stepwise increases in feeding volume, they were given 0.02 mg/kg atropine six times a day orally and the dose was decreased stepwise. RESULTS: Of the 19 infants, 17 (89%) ceased projectile vomiting after treatment with intravenous (median seven days) and subsequent oral (median 44 days) atropine administration. The remaining two infants required surgery. No significant complications were encountered. Ultrasonography showed a significant (p < 0.05) decrease in pyloric muscle thickness, but no significant shortening of the pyloric canal after completion of the atropine treatment. The patients exhibited failure to thrive at presentation, but were thriving at 6 months of age (p < 0.01). CONCLUSIONS: This atropine therapy resulted in satisfactory clinical recovery. Pyloric muscle thickness was significantly reduced.     

Metabolic alkalosis with hypoelectrolytemia in infants with cystic fibrosis

BACKGROUND: Infants with cystic fibrosis (CF) can develop episodes of hyponatremic hypochloremic dehydration with metabolic alkalosis when they sweat excessively, which is not caused by sweating in normal infants. We investigated the incidence of the metabolic alkalosis with hypoelectrolytemia in CF infants, the possible risk factors for its occurrence and the importance of the manifestation in the diagnosis of CF. METHODS: In order to evaluate the incidence and the risk factors for the development of this sweat-related metabolic disorder in CF, we reviewed the records of all children diagnosed as having CF before the age of 12 months in a 10-year period. Data analysis included medical history data, clinical features, biochemical parameters (blood pH, serum bicarbonate, sodium, chloride and potassium levels), sweat chloride test values, as well as genetic analysis data. RESULTS: The prevalence of metabolic alkalosis in association with low serum electrolyte concentrations (hyponatremia, hypochloremia, and hypokalemia) in infant CF population in our region was 16.5%. We found no season predilection in its occurrence. Early infant age, breast-feeding, delayed CF diagnosis, heat exhaustion and the presence of severe CF transmembrane conductance regulator mutations are predisposed factors for the development of metabolic alkalosis with hypoelectrolytemia. CONCLUSIONS: The results from our study suggest that metabolic alkalosis with hypoelectrolytemia is a relatively common manifestation of CF in infancy. The possibility of CF should be seriously considered in any infant with this metabolic disorder.     

Changing patterns in the diagnosis of hypertrophic pyloric stenosis

The records of 216 infants who had surgical correction of hypertrophic pyloric stenosis between 1980 and 1984 at the Children's Hospital of Alabama were reviewed. A significant increase in the reliance on upper gastrointestinal roentgenographic series and abdominal sonography for confirmation of the diagnosis of hypertrophic pyloric stenosis was noted in our patients when compared to previous reports. Despite the preoperative presence of a palpable pyloric mass in 192 (89%) of the patients, 174 (81%) had a diagnostic imaging procedure. Similar high rates of imaging studies were noted when the records of patients with hypertrophic pyloric stenosis from 1980 and 1984 were reviewed at three other institutions. Palpation of a hypertrophied pylorus is diagnostic of hypertrophic pyloric stenosis. Careful physical examination makes diagnostic imaging unnecessary in the majority of infants with symptoms suggesting hypertrophic pyloric stenosis. Diagnostic imaging for suspected hypertrophic pyloric stenosis should be used only for those infants with persistent vomiting in whom careful and repeated physical examinations fail to detect a palpable pyloric mass.     

Urinary chloride excretion distinguishes between renal and extrarenal metabolic alkalosis

The aetiology of normotensive hypokalaemic metabolic alkalosis is sometimes not obtainable from the history. Observations in adults indicate that the urinary chloride excretion is low in metabolic alkalosis of extrarenal origin. The chloride/creatinine ratio in random urines was therefore compared in 283 healthy children and in eight paediatric patients with metabolic alkalosis. The urinary chloride/creatinine ratio was reduced in four patients with metabolic alkalosis of extrarenal origin and within reference values or above in four patients with metabolic alkalosis of renal origin.Conclusion The study confirms that urinary chloride/creatinine ratio discriminates between extrarenal and renal forms of metabolic alkalosis.     

Suppression of plasma renin activity in a boy with chronic hyperkalemia

Chronic hyperkalemia (6.8 mmol/L [6.8 mEq/L]) was discovered in a boy, aged 13 years 7 months, with short stature, delayed puberty, and normal blood pressure. Additional studies revealed hyperchloremic metabolic acidosis (serum values: sodium ion, 139 mmol/L [139 mEq/L]; chloride, 113 mmol/L [113 mEq/L]; bicarbonate, 18 mmol/L [18 mEq/L]), a normal glomerular filtration rate, a subnormal renal threshold for bicarbonate reabsorption, and normal serum thyroxine, growth hormone, and cortisol values. Renal excretion of potassium ion was subnormal for the prevailing serum concentration of potassium ion but was increased normally by infusion of sodium sulfate. The serum aldosterone concentration was appropriate for a normokalemic subject, despite marked suppression of plasma renin activity (PRA) (supine/upright: aldosterone, 140/580 pmol/L [5/21 ng/dL]; PRA, 0.0/0.03 ng/L X s [0.0/0.1 ng/mL/h]). Treatment with chlorothiazide and sodium chloride resulted in correction of the abnormal electrolyte concentrations and an increase in linear growth velocity. Serum aldosterone concentrations did not change significantly during treatment, even though the PRA had increased (supine/upright: aldosterone, 110/920 pmol/L [4/33 ng/dL]; PRA, 0.89/2.17 ng/L X s [3.2/7.8 ng/mL/h]). In this patient, we conclude that (1) hyperkalemia was due to inadequate renal excretion of potassium ion; (2) the serum potassium ion concentration was the major stimulus to aldosterone secretion before treatment; (3) suppression of PRA was more likely due to hyperkalemia than to extracellular volume expansion.     

Is chloride depletion an important contributing cause of death in infants with bronchopulmonary dysplasia?

A retrospective analysis of infants with bronchopulmonary dysplasia requiring prolonged hospitalization (greater than 100 days) was carried out to determine those factors associated with fatal outcome. Twenty-three infants made up the study population. Eleven infants died and 12 survived (survivors). No differences were noted between the groups regarding ventilator requirement, radiographic changes, and medication use (digoxin, aldactazide), except for furosemide which was used twice as frequently in the group of infants who died v the group of infants who survived (P less than .001). Differences noted between the groups included moderate hypochloremia (chloride less than 80 mEq/L) in all 11 infants who died v six of 12 survivors, severe hypochloremia (chloride less than 70 mEq/L) in the nine of 11 infants who died v two of 12 survivors, metabolic alkalosis (pH greater than 7.45) in nine of 11 infants who died v three of 12 survivors, hypertension (systolic BP greater than 113 mm Hg) in eight of 11 infants who died v one of 12 survivors, decrease in head growth in ten of the 11 infants who died v one of the 12 survivors; these differences were all significant (P less than .001). The metabolic alkalosis and head growth changes appear to be related to the hypochloremia. The data suggest that chloride deficiency may be an important contributing factor in the genesis of poor outcome in infants with bronchopulmonary dysplasia and that close attention to chloride supplementation might influence outcome.     

The impact of a clinical guideline on imaging children with hypertrophic pyloric stenosis

Purpose: The purpose of the study was to evaluate the impact of a clinical pathway on the volume of imaging studies performed in children with suspected clinical diagnosis of hypertrophic pyloric stenosis. The pathway suggested referral to surgeons for clinical evaluation for palpation of the olive prior to ordering imaging studies. Only those children in whom the olive could not be palpated would be referred for imaging, and it was anticipated that imaging volume would be reduced following guideline implementation. Materials and methods: The database of the Health Policy and Clinical Effectiveness Department was used to evaluate all patients who had surgery for hypertrophic pyloric stenosis. The presence of a palpable olive and the type of imaging were evaluated both prior to and after the implementation of the clinical guideline. Results: Prior to the guideline, 85 infants had surgery for pyloric stenosis, with 83 of the 85 (97%) having imaging. After the implementation of the guideline, 90 infants had surgery for pyloric stenosis with 84 of 90 patients imaged (92%). A chi-square analysis demonstrated no significant difference in the percentage of children imaged in the two groups (P=0.104). Approximately one in five children referred for vomiting were diagnosed with hypertrophic pyloric stenosis. Conclusion: No significant change in imaging volume occurred following initiation of a guideline which recommended clinical evaluation for palpation of the olive prior to ordering imaging studies. Multiple factors probably contributed to the lack of demonstrated changes.This paper was presented at the Society for Pediatric Radiology Annual Meeting, San Francisco, California, April 2003.     

Use of calcium excretion values to distinguish two forms of primary renal tubular hypokalemic alkalosis: Bartter and Gitelman syndromes.

Clinical or biochemical findings were reevaluated in 34 pediatric patients with primary renal tubular hypokalemic metabolic alkalosis. The patients were subdivided into two groups. Bartter syndrome (primary renal tubular hypokalemic metabolic alkalosis with normocalciuria or hypercalciuria) was diagnosed in 18 patients with molar urinary calcium/creatinine ratios greater than 0.20, and Gitelman syndrome (primary renal tubular hypokalemic metabolic alkalosis with magnesium deficiency and hypocalciuria) was diagnosed in 16 patients with molar urinary calcium/creatinine ratios less than or equal to 0.20 and plasma magnesium levels less than 0.75 mmol/L. Some clinically important differences between the groups were observed. Patients with Bartter syndrome were often born after pregnancies complicated by polyhydramnios (8/18) or premature delivery (7/18) and had short stature (11/18) or polyuria, polydipsia, and a tendency to dehydration (16/18) during infancy (12/18) or before school age (18/18). Patients with Gitelman syndrome had tetanic episodes (12/16) or short stature (3/16) at school age (14/16). We conclude that the Bartter and Gitelman syndromes represent two distinct variants of primary renal tubular hypokalemic metabolic alkalosis and are easily distinguished on the basis of urinary calcium levels.     

Hypernatraemic dehydration in infants in Kuwait with special reference to therapy of associated metabolic acidosis

Over a period of 16 months 510 children with diarrhoea were admitted to the Al-Adan Hospital, Kuwait, of whom 26 (5.1%) developed hypernatraemic dehydration. Prominent clinical features included vomiting (92.3%), fever (84.6%) and convulsions (19.2%). The majority were below six months of age with a mean age of 3.1 months. The sex distribution was equal. Twenty infants (77%) had severe metabolic acidosis and were treated with a combination of sodium bicarbonate and 5% glucose in water until the acidosis was corrected after which a solution of sodium chloride replaced the use of sodium bicarbonate. The sodium concentration of the intravenous fluid varied from 15 to 30 mmol/l and was given at a rate of 100 to 120 ml/kg/day. One infant died. The 25 survivors, (96.15%), which included three who developed convulsions during treatment, recovered without any neurologic sequelae.     

Delayed diagnosis of cystic fibrosis in children with a rare genotype (ΔF508/R117H)

Objectives: In neonatal screening for cystic fibrosis (CF), infants recognised as ΔF508 heterozygotes require a sweat test to confirm the diagnosis. However, compound heterozygotes with ΔF508 and the R117H mutation are known to have non-diagnostic sweat chlorides (<60 mmol/L) at an early age. As genotyping for rare mutations is not readily available in Australia, there is a need to determine whether quantitative pancreatic stimulation tests could facilitate the diagnosis of CF in three infants with the ΔF508/R117H mutation.
Methodology Formal sweat testing, genotyping and pancreatic stimulation tests were performed in three subjects heterozygous for ΔF508 who initially had non-diagnostic sweat chloride results (40-60 mmol/L) but presented later with persisting chest symptoms and/or signs consistent with CF.
Results All three patients were shown to have the ΔF508/R117H genotype with initial sweat chloride results ranging from 40 to 58 mmol/L. Pancreatic stimulation tests demonstrated reduced enzyme secretion in two and decreased fluid, bicarbonate and chloride secretion in all three patients.
Conclusions In infants recognized as ΔF508 heterozygotes by the newborn screening programme, the presence of an equivocal sweat chloride does not exclude the diagnosis of CF. If such patients with an initially equivocal sweat chloride subsequently develop symptoms suggestive of CF and have a persisting non-diagnostic sweat chloride then the diagnosis of CF can be confirmed by more extensive genotyping if available or by pancreatic stimulation testing.     

Conservative treatment of infantile hypertrophic pyloric stenosis with intravenous atropine sulfate does not replace pyloromyotomy

Pyloromyotomy as described by Weber and Ramstedt has been the standard therapy for infantile hypertrophic pyloric stenosis since the 1960’s and conservative therapy has been abandoned. The objective of this study was to test the effectiveness of systemic atropine applied intravenously for 7 days as a conservative therapeutic strategy and as an alternative to primary operation. Forty-two consecutive term infants with infantile hypertrophic pyloric stenosis were enrolled in the study over a period of 5 years. After confirmation of the diagnosis they all received intravenous atropine at a dose of 0.04 mg/(kg day) and increased by 0.01 mg/(kg day) up to 0.12 mg/(kg day), given as 6–8 single doses per/day. Nine pairs of parents requested that their child should be operated before completing the 7 days of medical therapy. Surgery was necessary in 8 of the remaining 33 infants (24,.2%) who did not improve after 7 days of conservative treatment. Successful treatment with i.v. atropine sulfate was achieved only in 25/33 term infants at an average maximal dose of 0.11 mg/(kg day), without any major side effects. Intravenous atropine sulfate has been considered as a potential alternative therapeutic strategy in the treatment of infantile hypertrophic pyloric stenosis. Clinical improvement however was often not seen before the 6th or 7th day of intravenous treatment. A success rate for the conservative approach of only 75% at day 7 in our study does not favour atropine therapy, in view of success rates above 95% with surgical repair.     

Renal tubular acidosis in a patient with recurrent metabolic alkalosis

A 7-month-old infant with failure to thrive and recurrent episodes of vomiting and metabolic alkalosis was evaluated. Urine pH, serum bicarbonate, and urine PCO2-blood PCO2 studies were consistent with the diagnosis of distal renal tubular acidosis (RTA-type I). Analysis of serum potassium and chloride levels during periods of alkalosis and acidosis revealed that potassium depletion and hypochloremic volume contraction served to maintain the alkalotic state despite the presence of an underlying chronic acidosis. This case represents an unusual presentation for renal tubular acidosis and suggests that, under certain conditions, renal tubular acidosis may predispose to the maintenance of a metabolic alkalosis.     

Characterization of HCO3-/CO2 pool sizes and kinetics in infants

The first bicarbonate pool sizes and kinetic data necessary for the interpretation of substrate oxidation studies have been determined in six fed, nonacidotic infants, ages 2.5 to 5 months. Following an intravenous bolus of NaH13CO3 (50 mumol/kg), breath samples were collected over 240 min for the analysis of breath 13CO2. Each breath 13CO2 disappearance curve was fitted to a multicompartmental bicarbonate model previously derived in adults. The mean sizes of the three bicarbonate pools were: 7.4 +/- 0.8 mmol/kg (central pool), 15.1 +/- 4.8 mmol/kg (rapidly exchanging peripheral pool), and 8.8 +/- 3.5 mmol/kg (slowly exchanging peripheral pool). The mean percentage dose recovery was 57 +/- 10%. The pool sizes suggested that extensive metabolic exchange of carbon between HCO3- and organic metabolites occurred in the infant.     

Water, Sodium and Acid-Base Balance in Premature Infants: Therapeutical Aspects

ABSTRACT. One of the main targets of fluid therapy in premature infants is to avoid variations in osmolality, which mainly means providing a stable sodium, glucose, and acid-base balance. Water, sodium, and acid-base balance were measured in 20 infants appropriate-for-gestational age with a gestational age 34 weeks. The infants were randomly assigned to one of two treatment groups. Fluid intake was restricted and air humidity in the incubator was high in order to minimize insensible water loss. Sodium intake in Group 1 was 2 mmol/kg/day and consisted of sodium chloride. Sodium intake in Group 2 was 4 mmol/kg/day and consisted of both sodium chloride and acetate. Weight loss was appropriate in both groups. In the high sodium intake group there was a tendency towards a more stable plasma sodium concentration than in the low sodium intake group. The use of sodium acetate was efficient and practical as normal acid-base balance was maintained. The protocol with restricted fluid intake (1st day 50 ml/kg, 2nd day 70 ml/kg, 3rd day 90 ml/kg, and 4th day 110 ml/kg), high air humidity, a sodium supply of 3 to 4 mmol/kg/day, and a slow correction of metabolic acidosis with sodium acetate, yields suitable guidelines in planning fluid and electrolyte therapy in premature infants 34 weeks' gestation.