Defending a traditional practice in the modern era: The use of lumbar puncture in the investigation of subarachnoid haemorrhage.

INTRODUCTION: Acute severe headache is a common medical presentation, and a common area of diagnostic uncertainty. Subarachnoid haemorrhage (SAH) is the cause in a minority of patients and has a high rate of morbidity and mortality. Therefore, its conclusive diagnosis with computed tomography (CT) or lumbar puncture (LP) is paramount. With advancement in imaging technology, emerging evidence now suggests that LP is no longer required for a subset of patients as CT has 100% sensitivity in detecting SAH, when performed under specific conditions. OBJECTIVES: To assess the proportion of patients with conclusive CSF xanthochromia results following a negative CT scan in suspected SAH to determine the diagnostic efficacy of LP. METHODS: CSF bilirubin and oxyhaemoglobin spectrophotometric absorbance data from all centres in a regional health board were identified for consecutive patients over a 6-month period. Results were stratified as conclusive (positive or negative), or inconclusive according to national guidelines. RESULTS: 239 of 255 (93.7%) results were conclusive: 89.0% were negative (227 of 255). 4.7% of results were positive (12 of 255), revealing 4 cerebral aneurysms requiring treatment. 16 out of 255 (6.3%) samples were inconclusive, yielding 1 aneurysm requiring treatment. In the same period, there were 27 CT-positive cases of SAH. CONCLUSIONS: LP has a high diagnostic yield, eliminating the need for neurosurgical opinion or investigation in almost 90% of cases. The test is both cost and time efficient and subjects only a small number of patients to the radiation and contrast risks of angiography.

Early MRI diagnostics for suspected scaphoid fractures subsequent to initial plain radiography.

AIM: In the United Kingdom, diagnostic management of patients presenting to emergency department with a scaphoid injury varies. Follow-up plain radiographs, after an initial inconclusive X-ray, are common practice. We optimised the diagnostic pathway for these patients by focusing on the most appropriate diagnostic modality and on minimising the time to follow-up diagnostics. MATERIALS AND METHODS: A baseline audit in the period 2008-2009 involving a total of 184 patients was conducted, and after the introduction of new local guidelines for scaphoid injury diagnostics, a follow-up audit involving 79 patients was undertaken in 2010-2012. RESULTS: In the original audit, 130 patients had only scaphoid radiographs, of which 23 underwent initial and follow-up X-rays, and 107 initial-only radiographs. Of those 23, just one single patient (4%) displayed a scaphoid fracture. Others underwent three imaging procedures: initial radiographs, follow-up radiographs and either bone scan (41 patients) or MRI (13 patients). A further 6/41 (15%) and 4/13 (31%) fractures were detected by bone scan and MRI, respectively. In the re-audit, when MRI replaced follow-up X-rays and bone scans, 7 out of 77 (9%) patients were diagnosed with scaphoid fracture. Time from initial plain radiograph to follow-up MRI was reduced from an original mean of 36 to 14 days during the re-audit period. CONCLUSION: The introduction of early MRI enhances scaphoid injury diagnostics and accelerates patient management. We therefore endorse the introduction of this approach on a wider scale through an update of the clinical guidelines for scaphoid injuries.