AUDIT OF ONCE-DAILY DOSING GENTAMICIN THERAPY IN NEUTROPENIC FEVER

During a 12-month study, 42 adult patients with febrile neutropenia (granulocytes <1 × 10⁹/l) were treated with once-daily gentamicin (5 mg/kg). Serum gentamicin trough levels were measured 24 hours after the first dose, then twice weekly if <1 mg/l. Gentamicin was halved if the trough level was 1-2 mg/l and usually stopped if >2 mg/l. One hundred and sixty samples were assayed: 122 (76%) <1 mg/l, 27 (17%) I-2 mg/l and 11 (7%) >2 mg/l. All 1-2 mg/l samples and three of the >2 mg/l samples (taken at the wrong time) reverted to <1 mg/l with dosage adjustment. The protocol proved simple and effective with a low incidence of gentamicin-associated nephrotoxicity (7%) and no sepsis-related deaths.     

MR imaging of acute spinal cord trauma

The thoracic spinal cords of five mongrel dogs were imaged with a 1.5 T MR scanner before and after trauma induced by a well-established method of spinal cord impaction that produces central cord hemorrhagic necrosis. The anesthetized dogs were studied acutely with a 5-in. circular surface coil, 12-cm field of view, sagittal and axial partial-saturation (TR = 600, TE = 25 msec) and spin-echo (TR = 2000, TE = 25-100 msec) techniques. One normal dog was used as a control. The cords were surgically removed and histologically examined. Direct correlation of the pathologic findings and imaging data showed that at the level of trauma there was obliteration of epidural fat and CSF spaces secondary to central cord hemorrhage and edema. The traumatized cords expanded to fill the bony canal, and there was loss of visualization of the internal anatomy of the cord (gray- and white-matter structures). We conclude that MR can accurately identify cord hemorrhage and edema within a few hours of spinal trauma.     

Intussusception presenting to a paediatric accident and emergency department.

In a retrospective study, 110 patients episodes with intussusception presenting to a paediatric accident and emergency (A&E) department were reviewed, with particular attention being paid to presenting symptoms, time to diagnosis, radiological investigation, management and outcome. Between 1983 and 1993 100 patients presented to this department with 110 episodes of intussusception. Delay in diagnosis of greater than 12 h from initial medical contact was associated with increased morbidity. Associated factors in delayed diagnosis were departure from the classical symptoms (pain, vomiting and blood per rectum) and the presence of diarrhoea. General practitioner (GP) referral was to the medical team (rather than the surgical team) in around 50% of cases. Irrespective of the specialty of the first hospital doctor to see the patient only 42% were diagnosed correctly within 3 h of admission. In this population diarrhoea is a common symptom of intussusception and should alert the clinician rather than reassure. Because of its many presentations and relative rarity, intussusception remains a difficult condition to diagnose.     

Salmonella meningitis in children in Far North Queensland

Abstract: Seven cases of Salmonella meningitis have occurred in infants in Far North Queensland since 1982. The mean age of onset was 2.8 months, and at least five of the cases were caused by Salmonella virchow. Five of the cases had significant complications during the acute illness: all required prolonged (median 34 days) inpatient management, and four developed permanent neurological sequelae. S. virchow is the serovar most frequently isolated from infants in Far North Queensland. The source of S. virchow infections in these infants remains uncertain, but transmission may occur through cross-infection and person-to-person transmission in the home.     

Herniation pits of the femoral neck: appearance at MR imaging

Herniation pits of the femoral neck are benign lesions recognized because of their characteristic appearance and location on plain radiographs. The appearance of this lesion in seven magnetic resonance (MR) examinations of the hips in five patients is described. MR revealed a well-marginated, round to oval defect in the superior lateral quadrant of the femoral neck with anterior cortical extension in all cases. With T1 weighting the signal intensity within each lesion was uniformly low. All but one case revealed a peripheral margin of absent signal intensity on T2-weighted and out-of-phase images. The MR appearance and location are sufficiently characteristic to allow identification of this lesion and aid in differentiating it from pathologic processes such as avascular necrosis, with which it may be confused.