Imaging paediatric blunt abdominal trauma in the emergency department: ultrasound versus computed tomography.

OBJECTIVE: To determine whether an abdominal ultrasound scan performed by paediatric radiologists is effective in the diagnosis of abdominal injuries in children. METHOD: A retrospective cohort study was undertaken of all children who presented with blunt abdominal trauma to a paediatric teaching hospital (RHSC) over a 5-year period between 1 January 2001 and 31 December 2005. Hospital notes and radiology computer systems were interrogated and data were collected and analysed. RESULTS: Of the 80 children with blunt abdominal trauma, 56 (70%) had abdominal imaging and 23 (30%) had no imaging. Of the 56 imaged, 48 (86%) had an USS of which 25 (52%) were positive (16 demonstrated solid organ injury, 8 free fluid and 1 suspected bladder rupture); 3 of these went on to have a CT scan. 23 had a normal USS; 2 of these children went on to have a CT scan because of a high index of suspicion for small bowel perforation due to their mechanism of injury and clinical signs. Both of these CT scans were normal. Eight children (14%) had a CT scan as the primary investigation, 6 of which (75%) were positive (5 demonstrated liver lacerations and 1 free fluid with no obvious source). All these abnormalities were demonstrated on follow-up USS. 23 children had no abdominal imaging and once their symptoms and signs had settled they were safely discharged home. CONCLUSION: Abdominal USS performed by paediatric radiologists is an accurate method of assessing abdominal injuries. However, CT scanning can assess certain abnormalities such as pancreatic or duodenal injuries and small amounts of free intraperitoneal air more accurately. The importance of serial clinical examination must not be overlooked.

Can we abolish skull x rays for head injury?

OBJECTIVES: To assess the effect of a change in skull x ray policy on the rate of admission, use of computed tomography (CT), radiation dose per head injury, and detection of intracranial injuries; and to compare the characteristics of patients with normal and abnormal head CT. DESIGN: Retrospective cohort study. SETTING: UK paediatric teaching hospital emergency department. PATIENTS: 1535 patients aged between 1 and 14 years with a head injury presenting to the emergency department between 1 August 1998 and 31 July 1999 (control period), and 1867 presenting between 1 August 2002 and 31 July 2003 (first year of new skull x ray policy). INTERVENTION: Hospital notes and computer systems were analysed and data were collected on all patients presenting with a head injury. RESULTS: The abolition of skull x rays in children aged over 1 year prevented about 400 normal skull x rays being undertaken in period 2. The percentage of children undergoing CT rose from 1.0% to 2.1% with no change in the positive CT pick up rate (25.6% v 25.0%). There was no significant change in admission rate (10.9% v 10.1%), and a slight decrease in the radiation dose per head injury (0.042 mSv compared to 0.045 mSv). CONCLUSIONS: Skull x rays can be abandoned in children aged 1 to 14 without a significant increase in admission rate, radiation dose per head injury, or missed intracranial injury. The mechanism and history of the injury and a reduced Glasgow coma scale are probably the most important indicators of significant head injury in children.

Imaging infants with head injury: effect of a change in policy.

OBJECTIVE: Head injury is one of the commoner injuries presenting to the emergency department (ED). Infants are hard to assess clinically and emphasis has been placed on radiological examination. Skull radiographs, however, are not a reliable indicator of intracranial injury. As a result of this the policy in this ED was revised so that skull radiographs were only to be performed in those infants less than 1 year with visible evidence of head injury or a suspicious history for non-accidental injury. METHODS: Retrospective cohort study of all infants less than 1 year who presented with head trauma to the ED of a paediatric teaching hospital between 1 August 1998 and 31 July 1999, and between 1 August 2002 and 31 July 2003. Hospital notes and radiology computer systems were examined and data were collected and analysed. RESULTS: 181 infants aged less than 1 year presenting to the ED in 1998/9 and 190 infants in 2002/3. Altogether 140 (77.3%) infants had a skull radiograph in 1998/9, five (3.6%) identified skull fractures. During 2002/3, 56 (29.5%) infants had a radiograph, a reduction of 47.5%, of which three (5.4%) had skull fractures. All fractures had reported haematomas to their scalp. The change in policy decreased the total radiation dose to the population by 9.4 mSv. No significant injuries were missed as a result of the change in policy. INTERPRETATION: In infants under 1 year, unless non-accidental injury is suspected, it is suggested that skull radiographs should only be performed when there are visible signs of a head injury.

Distinctive patterns of release of neuroendocrine peptides after nasal challenge of allergic subjects with ryegrass antigen.

The concentrations of the neuropeptides substance P, somatostatin, and calcitonin gene-related peptide in human nasal secretions were quantified by radioimmunoassays, concurrently with that of histamine, in the course of nasal challenge of allergic and control subjects with ryegrass antigen to examine contributions of neuromediation of the tissue response. Each of the neuropeptides and histamine were detected in nasal lavage fluid prior to challenge. In allergic patients, but not normal controls, antigen evoked significant increases of 3-fold in histamine at 15-60 min, 1.5- to 4-fold in calcitonin gene-related peptide at 15 min-24 hr, and more than 2-fold in somatostatin at 6 hr, without altering the concentration of substance P in nasal lavage fluid. The identity of the neuropeptides was confirmed chromatographically. Thus calcitonin gene-related peptide may mediate nasal congestion directly and somatostatin may be one of the factors regulating the late involvement of basophils and mast cells in allergic rhinitis.

A comparison of pirenzepine and cimetidine inhibition of centrally-mediated gastric acid and pepsin secretion in the gastric-fistula cat.

The effects of pirenzepine, a muscarinic antagonist, and cimetidine, a histamine H2-receptor antagonist, on 2-deoxy-D-glucose-stimulated gastric secretion were investigated in the gastric-fistula cat. Both drugs inhibited gastric acid secretion in a dose-related manner; the oral ED50 of pirenzepine was 0.37 (0.22-0.59) mg/kg and cimetidine was 4.6 (3.3-5.8) mg/kg. The two drugs affected pepsin secretion in characteristically different ways. The inhibition of pepsin secretion by cimetidine was small and inconsistent when compared with the effect on acid. Throughout the dose-range cimetidine tended to reduce volume more than pepsin secretion. The resulting rise in concentration of pepsin suggested that cimetidine had an indirect effect on pepsin secretion. In contrast, pirenzepine exerted a direct effect on both acid and pepsin. Hence at doses producing a 50% inhibition of acid secretion pirenzepine and cimetidine reduced pepsin secretion by 78% and 25% respectively. These observations were consistent with the concept that muscarinic receptors and not histamine H2-receptors are involved in the regulation of pepsin secretion.

Localization of the effect of acetylcholine in regulating intestinal ion transport.

1. The location of the site involved in the secretory response of rat jejunum and colon to ACh was investigated by selectively damaging either the villi of the jejunum and the surface epithelium of the colon or the crypts. 2. The secretory response induced by ACh was measured both in terms of changes in electrical activity and chloride fluxes. 3. Exposure of the mucosa to 2 M-Na2SO4 for 30 min selectively damaged the jejunal villi and colonic surface epithelium but did not reduce the increased potential difference and current generated by ACh. 4. When resistance changes were taken into account the colonic response was markedly increased after Na2SO4 treatment although the jejunal response was unchanged. Under control conditions ACh reduced net Na absorption and stimulated Cl secretion by the colon. After exposure to Na2SO4 only the Cl secretory component of the ACh response remained, thus accounting for the enhanced effect. 5. Cycloheximide, administered I.V. at a dose of 12 mg/kg, damaged the crypts after 2 hr without affecting the villi of the jejunum or the surface epithelium of the colon. After cycloheximide treatment the increased potential difference, current and net Cl secretion induced by ACh were significantly reduced. 6. The crypts therefore appear to be the site primarily involved in the secretory response of rat jejunum and colon to ACh, although in the colon an inhibitory effect on the Na transport process located in the surface epithelium was observed.

The role of acetylcholine in the regulation of ion transport by rat colon mucosa.

1. Acetylcholine increases the potential difference across rat proximal colon both in vivo and in vitro.2. There is a sigmoid relationship between the change in potential difference and the logarithm of the dose of acetylcholine. The dose-response curve is shifted to the left by neostigmine and to the right by atropine, suggesting that the action of acetylcholine is mediated by a muscarinic type of receptor.3. The dose-response curve for acetylcholine in vivo is not altered by the ganglion-blocking agents hexamethonium and pentolinium, suggesting a direct effect of this transmitter on the colon.4. Acetylcholine causes an increase in potential difference, a small decrease in resistance and hence a rise in the current generated by both normal and stripped everted sacs of rat colon.5. In the absence of sodium, the calculated current change produced by acetylcholine is reduced, and the removal of chloride has a similar inhibitory effect. The absence of bicarbonate does not significantly affect the response.6. Acetylcholine virtually abolished net sodium movement and induced net chloride secretion and these changes accounted for the increased short-circuit current.7. Acetylcholine had no effect on oxygen consumption by rings of colon.8. Tracts staining for acetylcholinesterase were observed running from the submucous plexus towards the mucosal epithelium.9. This study shows that acetylcholine can influence ion movement by rat colonic mucosa and suggests that the autonomic nervous system might be involved in the regulation of transport mechanisms in this tissue.