ULTRASOUND COMPARED WITH CLINICAL EXAMINATION IN INFANTILE HYPERTROPHIC PYLORIC-STENOSIS

Objectives-To assess the accuracy of clinical examination as compared with ultrasound imaging in the diagnosis of infantile hypertrophic pyl oric stenosis. Duration of hospital stay, time between admission and s urgery, and financial implications were also considered. Design-A pros pective study of patients referred to the surgical team with a possibl e diagnosis of pyloric stenosis from May 1993 to January 1995. Setting -Neonatal and paediatric surgical wards and imaging department of a pa ediatric teaching hospital. Subjects-116 patients referred to the surg ical team with a possible diagnosis of pyloric stenosis. Results-75 pa tients in this study had pyloric stenosis (64.6%). Clinical examinatio n had a sensitivity of 72%, specificity of 97%, with a positive and ne gative predictive value of 98% and 61% respectively. There were 16 dia gnostic errors (one false positive and 15 false negative). Ultrasound imaging had a sensitivity of 97%, specificity of 100%, with a positive and negative predictive value of 100% and 98% respectively. There was one diagnostic error (one false negative). Eight patients required re peat scans for confirmation of the diagnosis. On review of the initial scans in these patients, seven were noted to have inaccurate measurem ents due to poor technique. The average time between repeated scans wa s 28.2 hours. Ultrasound imaging cost pound 13.90 per scan and initiat ed a change in management only in the clinically false negative group at a cost of pound 52 per patient. The average duration of hospital st ay was 3.1 days and the mean time between admission and surgery was 19 .2 hours. The total cost for treatment of a patient with pyloric steno sis was pound 1602. Conclusion-Ultrasound imaging should be reserved f or those cases where clinical examination is negative and should be ca rried out by sonographers who see enough cases to maintain their exper tise.