Things that go beep: experience with an ED guideline for use of a handheld metal detector in the management of ingested non-hazardous metallic foreign bodies.

OBJECTIVES: To review compliance with our emergency department (ED) guideline on the imaging of ingested non-hazardous metallic foreign bodies in children, investigate adverse outcomes, and make suggestions for improving the guideline. METHODS: Retrospective analysis of patients presenting in a 3 year period to a paediatric ED with a history of possible metallic foreign body (MFB) ingestion, who were managed according to an ED guideline. RESULTS: We identified 430 episodes of possible MFB ingestion, of which 422 were eligible for inclusion in the study. Compliance with the guideline was 77.8% with no significant adverse events. The exclusion of symptoms as a criterion for x ray results in a reduction in the x ray rate of 56% in the symptomatic group with no increase in adverse events. CONCLUSION: A handheld metal detector (HMD) can be safely and reliably used in lieu of plain radiography to investigate children with a history of MFB ingestion, irrespective of symptoms and without incurring any significant adverse events.

A stochastic limit cycle oscillator model of the EEG.

We present an empirical model of the electroencephalogram (EEG) signal based on the construction of a stochastic limit cycle oscillator using Ito calculus. This formulation, where the noise influences actually interact with the dynamics, is substantially different from the usual definition of measurement noise. Analysis of model data is compared with actual EEG data using both traditional methods and modern techniques from nonlinear time series analysis. The model demonstrates visually displayed patterns and statistics that are similar to actual EEG data. In addition, the nonlinear mechanisms underlying the dynamics of the model do not manifest themselves in nonlinear time series analysis, paralleling the situation with real, non-pathological EEG data. This modeling exercise suggests that the EEG is optimally described by stochastic limit cycle behavior.

Presentation to accident and emergency with crying or screaming and likelihood of child protection registration.

OBJECTIVES: To determine whether children aged less than 2 years who present to accident and emergency (A&E) with crying or screaming as the only complaint, are more likely to be placed on the child protection register in later years than children who do not attend with crying or screaming alone. METHODS: The Sheffield Children's Hospital A&E database was examined for five years from 1 January 1992. Children who presented at triage with crying or screaming as their sole complaint were identified. Controls were taken from children who presented with any other complaint. Matches were made for sex, postcode and date of birth. All names were checked against against files that contained dates of past or present child protection registration. In January 2000, the children's age ranged from 3 to 10 years. The mean follow up period was six years (SD one year seven months). RESULTS: From 1 January 1992 until 31 December 1996, 450 children made 462 attendances to A&E with crying or screaming as their only complaint. Of these, 12 had been placed on the child protection register. Ten of the 450 control children had been registered. The odds ratio of subsequent child protection registration if a child presents in Sheffield with crying or screaming alone is 1.21 (95% confidence intervals 0.52 to 2.82). CONCLUSIONS: Presentation of young children who cry or scream for no clear reason is relatively common. Although child protection registration is not the same as abuse, it is the closest surrogate marker we have. This study shows there is no evidence of increased likelihood of child protection registration for children who present with crying or screaming alone and prejudices against parents of these children, if held, are inappropriate.

Detection and speciation of Cryptosporidium spp. in environmental water samples by immunomagnetic separation, PCR and endonuclease restriction.

Current methods for the detection of Cryptosporidium oocysts in water samples are both time-consuming and subject to variation in sensitivity. A genus-specific PCR assay was designed for the specific amplification of a 552-bp region of the 18S rRNA gene. Postamplification endonuclease restriction generated unique digest patterns that enabled differentiation between the three species, C. muris, C. baileyi and C. parvum, the major human pathogen. Theoretical restriction profiles for other Cryptosporidium species were also predicted. The assay routinely detected 10 oocysts in 10-ml purified oocyst preparations, but sensitivity was found to be 10(3)-10(4) -fold lower in environmental water samples. The use of Chelex resin and an immunomagnetic separation procedure overcame this inhibition. This provided detection levels of 10(1)-10(3) oocysts, depending on water turbidity. Rapid and sensitive pathogen detection methods are essential for the water industry. The results of this study demonstrate that PCR has the potential to improve current detection capabilities greatly by differentiating the major human pathogens from non-pathogenic species. This will greatly facilitate a closer examination of the epidemiology of this important pathogen.

Modified paediatric resuscitation chart.

OBJECTIVES: To determine whether a modified paediatric resuscitation reference chart improves the speed and accuracy of calculation of doses of drugs in simulated paediatric cardiopulmonary arrests when compared with the chart devised by Oakley. DESIGN: A prospective study in which a series of randomly assigned questions was used to compare the performance of doctors using the two charts. SETTING: Accident and emergency departments in two hospitals. SUBJECTS: 31 senior house officers. MAIN OUTCOME MEASURES: The speed and accuracy of calculation of volumes of drugs to be administered. RESULTS: The modified chart significantly increased the accuracy of the calculations (62/62 v 43/62, p < 0.01 [corrected]), the speed of correct calculations (6.8 v 36.0 s, p < 0.0001), and the number of calculations that were completed (62/62 v 50/62, p < 0.001). CONCLUSIONS: The modified paediatric resuscitation chart should supersede the existing chart.

The computer as a teaching aid: with particular reference to anaesthesia.

Computers have been used by a few anaesthetists for teaching purposes for a number of years. Well constructed programs have the capacity to realistically present material which would not be available by other teaching methods. The advent of small portable computers has made this powerful teaching aid potentially available to a much larger group. It is likely that computer aided learning has a significant future in anaesthetic training and, in particular, for continuing medical education.

Transthoracic needle aspiration biopsy: accuracy of cytologic typing of malignant neoplasms.

A correlation was made between the cytologic and the histologic diagnoses of 162 patients who underwent transthoracic fine-needle aspiration biopsy in whom histologic proof of the nature of the aspirated lesion was available. Compared to the histologic diagnosis, the specific cell-type cytologic diagnosis was usually in agreement when reported as squamous cell carcinoma (86%), adenocarcinoma (86%), or small cell anaplastic carcinoma(86%). In patients with a known extrapulmonary primary malignant neoplasm, the cytologic specimen was extremely helpful in identifying a new pulmonary lesion as metastatic rather than as a primary lesion in the lung. These results warrant the more extensive use of fine-needle aspiration biopsy in patients with pulmonary neoplasms in whom the specific cell type of the malignant neoplasm has important implications in therapy.

The nearly occluded internal carotid artery: a diagnostic trap.

Nine cases of nearly occluded internal carotid artery (ICA) origins, usually simulating total occlusion, are presented. Correct diagnosis is aided by an awareness of the possibility of near occlusion of the ICA origin and by careful study of selective common carotid angiography with a long imaging sequence and subtraction. Carotid endarterectomy is the operative procedure of choice, since there may be startling apparent increase in size of the arterial lumen distal to the surgical repair. Many cases reported previously as internal carotid artery occlusion with successful endarterectomy may actually have been severe stenoses.

Computed tomographic and angiographic evaluation of hemangioblastomas.

The computed tomographic (CT) and angiographic findings in 14 patients with proved cerebellar hemangioblastomas were reviewed. Although the CT scan was abnormal in all patients who had hemangioblastomas which produced symptoms, angiography was far more sensitive than CT in detecting hemangioblastoma nodules and was usually more specific in characterizing the lesions. Angiography is recommended in any patients with CT demonstration of a cerebellar cyst, whether or not a mural nodule is apparent, and in patients with von Hippel-Lindau disease who have an abnormal cranial CT scan.

Radiology of olfactory neuroblastoma.

Olfactory neuroblastoma is often misdiagnosed pathologically. The authors reviewed eight such cases in which the pathological findings met strict criteria. These neoplasms are locally invasive in the nose and paranasal sinuses, with frequent intraorbital and intracranial extension as well as distant metastases. A rare primary presentation in the sphenoid sinus-clivus region is described. Computed tomography is the procedure of choice in defining intraorbital extension and is complementary to precision laminagraphy for defining intracranial extension. Angiography frequently shows hypervascularity and may be of further help in assessing intracranial extension.

C1-2 puncture with the patient supine for thoracic metrizamide myelography.

A tecnhique of performing metrizamide myelography with the patient supine and using lateral C1-2 puncture is described. Some advantages of this technique are discussed, especially for thoracic myelography.