An investigation of lumbar spine magnetic resonance referrals in two Irish university teaching centres: Radiology clinical judgement versus iRefer guideline compliance.

INTRODUCTION: With the annual increase in medical imaging demand, the appropriateness of the lumbar spine magnetic resonance imaging LSMRI referrals is worldwide gaining attention. This study aims to determine the appropriateness of LSMRI referrals and compare radiology clinical decisions to iRefer compliance based solely on referral text content. METHODS: Referral text was extracted from 1021 LSMRI referrals. Two review panels were recruited: three expert radiologists and three MRI radiographers. Radiologists classified cases as indicated or not indicated for scanning based on their clinical judgement. The radiographers classified based solely on iRefer guidelines. Majority voting for each case was applied to both review panels and reviewer agreement was tested using Kappa analysis. Logistic regression models were developed to identify medical disciplines associated with high rates of indicated referrals. RESULTS: 21.7% and 11.9% of the cases were found not indicated for MRI for radiologists and radiographers, respectively. Radiology review identified 18% of the GPs referrals as not indicated and 17% in the radiographers' review. Panel agreement was fair: Kappa values of 0.23 and0.26 for the radiologists and radiographers respectively. Neurosurgery was associated with the highest rate of indicated referrals across both review panels: oncology referrals raised the highest number of open comments. CONCLUSION: The study identified a lower number of not indicated referrals compared to previous research. Findings indicate the importance of both guidelines compliance and clinical judgement to optimise practice. IMPLICATIONS FOR PRACTICE: Findings in this study found that even when strict instructions were given to the MR radiographers to vet referrals using the iRefer guidelines, ambiguity within the guidelines resulted in variations in decision-making. This suggests that detailed protocols are required to support radiographers in the vetting process to ensure a standardised approach.

A study of uranium lung clearance at a uranium processing plant.

A study has been made of the retention of uranium in the lungs of persons exposed chronically to low levels of uranium aerosols at the Y-12 Plant. A new characterization of the workplace aerosols shows an activity median aerodynamic diameter of 8 microns to be representative of the uranium oxides handled at the Y-12 Plant. The usual ICRP respiratory-system model is employed in conjunction with bioassay data from worker exposures to deduce a new set of parameters to describe lung clearance of these aerosols. This new assessment leads to good agreement between in vivo estimates of uranium lung burdens.

Blunt abdominal trauma.

Blunt abdominal trauma is a possible sequel of many accidents and can result in death from hemorrhage or sepsis if it is not detected early and managed aggressively. A thorough history of the causative accident, a systematic abdominal examination, selected laboratory studies, and x-ray films are helpful in establishing the diagnosis. Peritoneal lavage is, however, the most reliable assessment tool (besides an exploratory laparotomy) for confirming significant viscus injury and intra-abdominal hemorrhage. Nurses who are assisting in the evaluation of trauma victims should be thoroughly familiar with the mechanics responsible for blunt abdominal injury, the initial steps for stabilizing the victim, and the usual tests and procedures that aid in diagnosis.

Guardianship in the elderly and the Community Care Act: more of the same?

OBJECTIVE: Guardianship has been used in increasing numbers of elderly mentally disordered Scots in the past decade. During this time, the Community Care Act (CCA) encouraging the provision of care for individuals in their home has been enacted. This study aimed to see if the increased use of guardianship could be due to the use of orders to maintain at-risk elderly people in their homes. DESIGN: A retrospective survey of all new guardianship orders in people aged 65 or over, comparing those in the two years before the CCA with those in the two years after. Cases were identified using the Mental Welfare Commission (MWC) database. MWC records for the individuals placed on guardianship were examined for data on demographics, social circumstances and perceived risks, together with duration and outcome of orders. Hospital case records were examined for diagnostic information. SUBJECTS: All individuals aged 65 or over placed on guardianship under the Mental Health (Scotland) Act 1984 between 1st April 1991 and 31st March 1995. RESULTS: 85 new guardianship orders were identified, 22 before and 63 after CCA. Most were female (82% before and 85% after) and suffered from organic mental disorders (82% before and 84% after). The modal duration of orders for both groups was six months with a trend towards longer orders being noted in the after CCA group. The majority of orders resulted in the placement of the individual in nursing or residential home care (82% before and after CCA). CONCLUSION: The increased use of guardianship in elderly mentally disordered individuals is not explained by the use of orders to maintain them at home. It is likelier that the process of social work assessment required by the CCA highlights more cases where guardianship could be used.

Practolol in acute myocardial infarction.

A double blind trial of practolol in coronary heart disease has been conducted for 2 years. In 298 patients with acute myocardial infarction there was no reduction in overall mortality. In a group with initial heart rate over 100 per minute mortality was significantly lowered up to 1 year. Of 484 patients with coronary heart disease treatment for 2 years did not produce a significant reduction in infarction or sudden death. Beta-adrenergic blocking drugs have been shown to reduce left ventricular work and to have an antiarrhythmic action. On these grounds they would seem theoretically to have a place in the management of acute myocardial infarction. Practolol is a cardio-selective beta-blocking agent with an intrinsic sympathomimetic action, but devoid of local anaesthetic effect. It has been found effective in post infarction arrhythmias (1). In early infarction it reduces the area of necrosis as measured by surface ST segment mapping (2).

Bacteriocin production by Clostridium acetobutylicum in an industrial fermentation process.

High titers of a noninducible bacteriocin were produced by Clostridium acetobutylicum in a molasses fermentation medium used for the industrial production of solvents. Release of the bacteriocin towards the end of the exponential growth phase was accompanied by lysis of the culture and inhibition of the production of solvents. The producer cells were sensitive to the bacteriocin, which only affected other C. acetobutylicum strains and a Clostridium felsineum strain. The thermolabile bacteriocin was not inactivated by protease enzymes and had no optimum stability between pH 4 and 5. The sedimentation coefficient of the bacteriocin was 6S.

Simple lignocaine regimen for transit to hospital after myocardial infarction.

A simple combined intravenous/intramuscular regimen is described for lignocaine administration in the early vulnerable stage of myocardial infarction. Plasma levels in the therapeutic range are attained. This allows adequate drug protection during transport to hospital when an intravenous regimen may be impractical or impossible.

Effect of very early intervention with metoprolol on myocardial infarct size.

All patients with a presumptive diagnosis of myocardial infarction, who were seen within six hours of the onset of symptoms and had no reason for exclusion, were considered for entry into a trial to compare the effects of metoprolol and placebo on creatine kinase MB isoenzyme release. The trial was randomised and double blind. The median time from onset of symptoms to receiving trial drug was just under two hours. Two hundred and four patients (of whom 120 had myocardial infarction) received metoprolol and 187 (of whom 105 had myocardial infarction) received placebo. Infarct size was estimated semiquantitatively using cumulative release of the cardiospecific isoenzyme, creatine kinase MB. Mean creatine kinase MB isoenzyme was less in patients who received metoprolol, but the reduction did not achieve statistical significance. Clinical problems related to early intravenous metoprolol were uncommon.

Very early intervention with metoprolol in suspected acute myocardial infarction.

A double blind randomized study of 800 patients was carried out to determine if very early intervention with metoprolol (15 mg I.V. followed by oral administration) in suspected acute myocardial infarction affected overall mortality in selected subgroups, (age, site of infarct, delay to intervention). Sudden death occurred less frequently in patients allocated to metoprolol but there was no significant difference in total mortality on discharge, at three months and at twelve months. Ventricular fibrillation after intervention was not significantly reduced. Adverse reactions did not occur significantly more frequently in patients assigned to metoprolol.

Comparison of the plasma concentrations and efficacy of mexiletine and of a slow-release preparation of mexiletine in patients admitted to a coronary care unit.

We determined if therapeutic plasma concentrations of mexiletine (0.75-2.0 microgram/ml) could be maintained in patients admitted to a coronary care unit by twice daily dosing of a new slow-release (S.R.) formulation of mexiletine. Twenty patients, 14 with acute myocardial infarction, entered the first study and received either 250 mg conventional mexiletine at 0.8, and 14 h or 360 mg S.R. mexiletine at 0 and 12 h each day for 7 days. Blood samples were taken daily for measurement of plasma mexiletine concentrations. A continuous 24 -h ECG recording was obtained in all patients between days 3 and 6. The mean plasma concentration was greater on all days in the group that received conventional mexiletine; these differences were most marked during the first 15 h on day 1. The mean trough values on days 2-7 were in the range 0.73-1.22 microgram/ml after mexiletine and 0.63-1.17 microgram/ml after S.R. mexiletine. The incidence of ventricular arrhythmias was the same in the two groups; side effects were less common in the group receiving S.R mexiletine. Since the plasma concentration increased slowly during day 1 with S.R. mexiletine, a second study was carried out in 19 similar patients who received 360 mg S.R. mexiletine, 720 mg S.R. mexiletine, or 360 mg S.R. mexiletine and 250 mg conventional mexiletine and 12 h later 360 mg S.R. mexiletine. The plasma concentration increased most rapidly after the third regime, reaching 0.97 +/- 0.09 microgram/ml at 3 hours. These results show that therapeutic plasma concentrations of mexiletine can be maintained by the 12-hourly administration of 360 mg S.R. mexiletine, but that an additional loading dose of 250 mg mexiletine increases the plasma concentration more rapidly.

Diagnosis of myocardial infarction from serum creatine kinase MB isoenzyme (CKMB) measurement.

The cardiospecific isoenzyme MB of creatine kinase (CKMB) has previously been shown to be of value in the diagnosis of myocardial infarction (MI). We studied 418 admissions to a coronary care unit (CCU) with suspected MI and calculated the sensitivity, specificity and positive and negative predictive values for several CKMB test functions. Several functions performed better than any combination of the other enzymes in common use. 97% of patients achieving a CKMB activity of at least 15 U/l did so between 6 and 30 h following the onset of symptoms. The present study confirms that the use of the CKMB isoenzyme leads to an earlier and more accurate diagnosis or exclusion of MI compared to the "cardiac enzyme series". The timing of blood sampling for CKMB estimation is also discussed.