Administration of open-ended test questions by computer in a clerkship final examination.

PURPOSE: To evaluate the reliability, efficiency, and cost of administering open-ended test questions by computer. METHODS: A total of 1,194 students in groups of approximately 30 were tested at the end of a required surgical clerkship from 1993 through 1998. For the academic years 1993--94 and 1994--95, the administration of open-ended test questions by computer was compared experimentally with administration by paper-and-pencil for two years. The paper-and-pencil mode of the test was discontinued in 1995, and the administration of the test by computer was evaluated for all students through 1998. Computerized item analysis of responses was added to the students' post-examination review session in 1996. RESULTS: There was no significant difference in the performances of 440 students (1993--94 and 1994--95) on the different modes of test administration. Alpha reliability estimates were comparable. Most students preferred the computer administration, which the faculty judged to be efficient and cost-effective. The immediate availability of item-analysis data strengthened the post-examination review sessions. CONCLUSION: Routine administration of open-ended test questions by computer is practical, and it enables faculty to provide feedback to students immediately after the examination.

Cost-effective imaging approach to the nonbilious vomiting infant.

OBJECTIVE: To develop a cost- and time-effective algorithm for differentiating hypertrophic pyloric stenosis (HPS) from other medical causes of emesis in infants referred from community-based pediatricians and family practitioners to the imaging department of a tertiary children's care facility. METHODS: Eighty-nine vomiting infants (22 females, 67 males) between the ages of 11 and 120 days (mean, 43.5 days) had received nothing by mouth for at least 1 hour before the study. Each child was assessed for duration of vomiting, status of body weight, time and volume of last ingestion, and time of last emesis. A #8 French (Sherwood Medical, St Louis, MO) nasogastric feeding tube was placed in the child's stomach. The contents were aspirated and measured to determine likelihood of HPS. An aspirated volume >/=5 mL implicated gastric outlet obstruction, and ultrasonography (US) was performed. If this study was positive for HPS, the patient was referred for surgery. If US was negative, an upper gastrointestinal series (UGI) was performed. An aspirated stomach contents volume <5 mL suggested a medical cause for the emesis, and UGI was performed. Pediatric surgeons with no knowledge of the volume results palpated the abdomens of 73 of 89 infants (82%). RESULTS: Twenty-three of 89 patients (25%) had HPS. The aspirate criteria for HPS had a sensitivity of 91%, a specificity of 88%, and an accuracy of 89%. Of the false-positive studies (total = 8), six were related to recent significant ingestion (within 2 hours of the study), and two were attributable to antral dysmotility. The surgeons palpated the mass in 10 of 19 patients (53%). Sensitivity and specificity were 53% and 93%, respectively. Only 6 of 89 infants (7%) required both US and UGI to determine the etiology of the nonbilious vomiting. By performing the UGI in 66 patients, it was also found that 14% had slow gastric emptying and 79% had gastroesophageal reflux. Eighty-one percent of the gastroesophageal reflux was significant. CONCLUSION: The volumetric method of determining the proper imaging study is cost- and time-effective in the evaluation of the nonbilious vomiting infant for pyloric stenosis. If US was performed initially in all patients referred for imaging, two studies would have been performed in 68 of 89 patients (76%) to define the etiology of the emesis. Because we used the volumetric method, 62 fewer imaging studies were performed, representing a savings of $4464 and 30 hours of physician time. If children are given nothing by mouth for 3 to 4 hours before gastric aspiration, the specificity of the volumetric method improves to 94%, and the accuracy improves to 96%.

Five-year follow-up of neonates with reconstructed right common carotid arteries after extracorporeal membrane oxygenation.

OBJECTIVE: Serial Doppler ultrasonography and long-term neurodevelopmental follow-up outcomes were evaluated prospectively in neonates whose right common carotid artery (RCCA) was reconstructed after extracorporeal membrane oxygenation (ECMO). METHODS: Children with RCCA reconstruction (n = 34) were monitored for 3.5 to 4.5 years by Doppler ultrasonography for arterial patency, and 28 had IQ testing by 5 years. A comparison group consisted of 35 infants who had RCCA ligation after ECMO. Neonatal electroencephalograms and computed tomography/magnetic resonance imaging scans were also compared. RESULTS: Reconstructions were successful (<50% RCCA stenosis by Doppler ultrasonography) in 26 (76%) of 34 children, 3 (9%) had >/=50% stenosis, and 5 (15%) had occlusion. No significant differences were seen between reconstructed and ligated groups in neonatal complications or ECMO courses. Occurrence of marked neonatal electroencephalographic abnormalities did not differ between groups. Abnormalities on computed tomography/magnetic resonance imaging scans (4 of 31 vs 11 of 29, P =.025) and cerebral palsy (0 of 34 vs 5 of 35, P =.054) were more common in infants with RCCA ligation. No differences were seen in developmental or IQ scores between the 2 groups, and 4 in each group had cognitive handicaps (at least 1 IQ score <70). CONCLUSIONS: Most RCCA reconstructions remained patent, with 24% showing significant stenosis or occlusion. Compared with a historical control group, patients with RCCA reconstruction had fewer brain scan abnormalities and tended to be less likely to have cerebral palsy. RCCA reconstruction after venoarterial ECMO may improve outcome.

Impact of a standardized patient intervention to teach breast and abdominal examination skills to third-year medical students at two institutions.

BACKGROUND: This study examined whether a single intervention with standardized patients (SPs) as a supplement to traditional teaching during the surgery clerkship would enhance the breast and abdominal examination skills of third-year medical students. METHODS: During the academic year 1994-1995, 153 students from two institutions were assigned to control or experimental groups. At institution A, all students underwent pretests and posttests with SPs; at institution B, no pretest was conducted. All experimental students received group and one-to-one instruction with SPs during the intervention session. RESULTS: At posttest, the experimental group performed better than the control group on breast examination (P = 0.002), professionalism during this examination (P <0.001), abdominal examination (P <0.001), and professionalism during the latter examination (P = 0.050). The improvement from pretest to posttest at institution A was significantly greater in the experimental group than the control group for the breast examination (P = 0.036) and the abdominal examination (P <0.001). Analyses on a variety of specific tasks within each examination were also performed. CONCLUSION: A single intervention with SPs teaching breast and abdominal examinations resulted in significant enhancement of these clinical skills.

3-Year-old phenotypic female with campomelic dysplasia and bilateral gonadoblastoma.

The authors report the case of bilateral gonadoblastomas in a phenotypic female, with a 46,XY karyotype, with campomelic dysplasia. Although campomelic dysplasia with gonadal dysgenesis should be expected to contribute to an increased risk of gonadoblastoma, this is the first documented case report of campomelic dysplasia and gonadoblastoma. Phenotypic females with campomelic dysplasia should be karyotyped once the skeletal dysplasia is recognized. phenotypic females with campomelic dysplasia should undergo gonadectomy if their karyotype includes a Y chromosome or fragment.

Bypass cannulas utilized in extracorporeal membrane oxygenation in neonates: radiographic findings.

ECMO, as applied to neonates with severe respiratory failure, involves either a single or dual cannula system for removal of desaturated blood from and return of oxygenated blood to the patient. ECMO cannulas have undergone considerable change and improvement since the early 1980s, and a variety of cannulas are now available commercially for neonatal ECMO. All ECMO cannulas have a characteristic appearance on the chest radiograph, which is important in the assessment of cannula position and some cannula complications. We report the physical characteristics, advantages, disadvantages, and radiographic appearance of the most widely utilized neonatal ECMO cannulas.

Right common carotid artery reconstruction after extracorporeal membrane oxygenation: vascular imaging, cerebral circulation, electroencephalographic, and neurodevelopmental correlates to recovery.

OBJECTIVE: Right common carotid artery (RCCA) ligation after extracorporeal membrane oxygenation by venoarterial bypass may contribute to lateralized cerebral injury. Reconstruction of this artery after extracorporeal membrane oxygenation has proved feasible but has not been evaluated for neurologic outcome in any substantial series of infants. METHODS: We evaluated RCCA reconstruction in 47 infants treated with ECMO and compared their cerebrovascular and neuroanatomic imaging findings, electroencephalograms, and developmental outcomes with those of 93 infants who had no reconstruction. SUMMARY RESULTS: Color Doppler blood flow imaging revealed that carotid artery patency was usually obtained after RCCA reconstruction. Right internal carotid and bilateral anterior and middle cerebral arterial blood flow velocities were generally higher, and were more symmetrically distributed in infants with reconstructed RCCA. Electroencephalography did not disclose an increased risk of deterioration or marked abnormalities in infants after reconstruction, nor were neuroimaging findings consistent with an increased number of either focal or generalized abnormalities. Neurodevelopmental follow-up revealed no differences in the incidence of delays between those with a reconstructed RCCA and those with a ligated RCCA during the first year of life. CONCLUSIONS: Reconstruction of the RCCA after extracorporeal membrane oxygenation may facilitate normal distribution of cerebral blood flow through the circle of Willis, and may augment both left and right middle cerebral artery blood flow immediately after decannulation. The long-term consequences of either ligation or reconstruction of the RCCA will require careful scrutiny, however, before either course is recommended routinely.

Thoracic complications of extracorporeal membrane oxygenation: findings on chest radiographs and sonograms.

Neonates treated with extracorporeal membrane oxygenation (ECMO) for respiratory failure have a high frequency of complications related to systemic anticoagulation, ECMO and other life-support lines and catheters, and the antecedent pulmonary disease. Many of these complications involve the thorax and can be defined on chest radiographs or thoracic sonograms. The purpose of this essay is to illustrate the findings of the various thoracic complications of ECMO on chest radiographs and sonograms. This study is based on a review of the medical records and findings on chest radiographs and sonograms of 150 neonates who were treated with ECMO at our institution.

Right common carotid artery reconstruction in neonates after extracorporeal membrane oxygenation: color Doppler imaging.

Thirty-three neonates treated for reversible respiratory failure underwent reconstruction of their previously ligated right common carotid arteries (RCCAs) immediately after extracorporeal membrane oxygenation (ECMO). Cerebral color Doppler imaging, performed during and repeatedly after ECMO, revealed antegrade flow in the right internal carotid artery (ICA) in all neonates within 6 days after successful RCCA reconstruction. Mean ICA velocity was significantly less in the right artery compared with the left during ECMO and within 1 hour of reconstruction, but there was no difference after 12 hours. In neonates with successful RCCA reconstruction, the flow in the proximal right anterior cerebral artery was antegrade in only 4% of examinations during ECMO but became antegrade in 94% after 6 days. Retrograde flow in the right posterior communicating artery persisted in 50% of examinations performed 1 day after reconstruction. ICA flow become antegrade with symmetric velocities shortly after successful RCCA reconstruction. Collateral flow persists longer but decreases rapidly.

Cannula-induced vertebral steal in neonates during extracorporeal membrane oxygenation: detection with color Doppler US.

To determine whether flow through the subclavian artery might be affected during extracorporeal membrane oxygenation (ECMO), 40 neonates were examined with color Doppler ultrasound during and after ECMO. Retrograde flow in the right vertebral artery, noted in 12 of the 40 neonates (30%), was consistent with vertebral steal. Brachial systolic velocity was significantly less (P less than .01) on the right than on the left side in neonates both with and without vertebral steal. When the arterial cannula was removed after ECMO, vertebral artery flow became antegrade with symmetric velocity. Brachial velocities became symmetric in infants without vertebral steal, but mild asymmetry persisted in neonates who had had vertebral steal. Only one neonate had clinical signs of arm ischemia, which resolved promptly after removal of the cannula. No surviving neonates (n = 11) had neurologic findings related to the vertebrobasilar insufficiency over a 12-22-month period of observation. Vertebral steal appears to be common during ECMO and is resolved after removal of the cannula.

Medical students who enter general surgery residency programs: a follow-up between 1972 and 1986.

Although a few surgical residents do leave the surgical field, little research has been done into the eventual whereabouts of all surgical residents. We undertook this follow-up to find out what proportion of them enter the surgical field and to identify changing patterns over the past 15 years. We compared 593 medical school graduates on demographics, academic credentials, and surgery program directors' rating of their performance in the first postgraduate year (PGY-1). Sixty percent remained in general surgery, and about 26% moved to another specialty within the surgical field. During the mid-1970s, those who remained within the surgical field had better academic credentials on average than those who switched out of the surgical field. However, more recently, the trend has reversed. There were no differences between the groups on age or sex. These results suggest that some good students are being recruited into surgical programs but are later lost in major career switches. Perhaps these changes are related to residents' preferences for specialties that offer more controllable lifestyles than the surgical field.

Augmented-pressure colostogram in imperforate anus with fistula.

Most newborns with imperforate anus, except for those with very low varieties, undergo a diverting colostomy performed in the postnatal period, with definitive surgical repair at a later age. Accurate demonstration of the anatomy of any associated fistula between the rectum and urogenital tract is essential for optimal surgical management. An augmented-pressure distal segment colostogram is recommended prior to definitive repair, both to confirm the level of rectal atresia and to define any associated fistulous communication. We report a case of high imperforate anus with rectourethral fistula in which the fistulous tract was not identified on the conventional contrast colostogram but was readily delineated when an augmented-pressure modification of the technique was utilized. The technical aspects of augmented-pressure colostography are presented.

Right carotid artery ligation in neonates: classification of collateral flow with color Doppler imaging.

Extracorporeal membrane oxygenation (ECMO) is a lifesaving procedure for neonates that involves permanent ligation of the right common carotid artery. To determine the collateral flow patterns that develop after ligation, 58 infants underwent a total of 115 color Doppler imaging studies during (n = 54), within 1 month after (n = 36), or more than 1 month after (n = 25) ECMO. On the basis of the direction of flow in the right internal carotid artery (ICA) proximal and distal to the right posterior communicating artery (PCoA), 85 of the 115 studies were placed in one of three categories: (a) Anterior communicating artery (ACoA) dominance (n = 22), with retrograde flow in the entire right ICA, was most common during ECMO and was never seen more than 1 month after ECMO. (b) PCoA dominance (n = 47), with antegrade right ICA flow distal to the right PCoA but retrograde proximally, was common during all time periods. (c) External carotid artery (ECA) dominance (n = 16), with antegrade flow throughout the right ICA, was noted in 53% of studies more than 1 month after ECMO but in only 9% of earlier studies. Patterns changed from ACoA to PCoA to ECA dominance in 17 infants, but no change in the opposite direction was noted.

Treatment of neonatal necrotizing tracheobronchitis with extracorporeal membrane oxygenation and bronchoscopy.

Necrotizing tracheobronchitis has recently been described as a complication of mechanical ventilation of newborns with respiratory failure. Despite the use of bronchoscopy, 45% of the reported patients to date have died. In this study, we report the use of extracorporeal membrane oxygenation (ECMO) to stabilize two patients with necrotizing tracheobronchitis. While supported by bypass, both patients underwent prolonged bronchoscopies with removal of extensive amounts of tracheal debris. ECMO provided efficient oxygenation in the face of near total airway occlusion, and permitted far more extensive bronchoscopic debridement and lavage than would have been possible if the lungs were required for oxygenation. In addition, ECMO provided a period of lung "rest" during which ventilator settings were reduced, thus minimizing further barotrauma and allowing for lung and airway healing. Both patients recovered without significant respiratory sequelae. ECMO and bronchoscopy are effective forms of therapy for patients with life-threatening necrotizing tracheobronchitis when conventional modalities of treatment have failed.

The Rapunzel syndrome: an unusual trichobezoar.

We report the fourth and youngest patient in the literature with a trichobezoar extending from the stomach through the entire length of the small intestine to the cecum. The clinician must consider the possible presence of a "tail" in any patient presenting with a bezoar. Salient clinical features of trichobezoars are reviewed.

Use of the long tube in the management of patients with small-intestinal obstruction due to adhesions.

A retrospective analysis was performed of all patients admitted to our hospital over a six-year period with a diagnosis of small-intestinal obstruction due to adhesions, to assess the efficacy of treatment with long-tube decompression. Of 127 episodes of obstruction, two thirds responded to nonoperative treatment. Factors that were associated with a greater likelihood of success with long-tube decompression included incomplete obstruction, recurrent obstruction, and passage of the tube beyond the pylorus. Clinical findings were relatively reliable as diagnostic indicators of strangulation. The overall mortality was 1.5%, with no deaths due to a delay in operative intervention. A trial of long-tube decompression is recommended in patients presenting with a diagnosis of small-intestinal obstruction due to adhesions in the absence of clinical evidence of strangulation.