ABSTRACT
To investigate the role of lumbar puncture (LP) after a negative head computed tomography (CT) when ruling out subarachnoid hemorrhage (SAH) within 24 h of symptom onset. In a single-center, retrospective cohort study, we studied a consecutive series of patients from 2011 to 2015. All patients underwent CT or CT following LP to rule out SAH. Patients were categorized into four groups depending on the time of symptom onset to initial head CT: 0-6 h, 6-12 h, 12-24 h, and over 24 h. Experienced radiologists interpreted all CT scans. We investigated the sensitivity, specificity, and negative predictive value (NPV) of noncontrast CT in detecting SAH. Of 539 patients with suspected SAH and negative CT, 280 (51.9%) had their CT performed within 24 h of symptom onset. None of these patients had SAH. Five (1.9%) out of 259 patients with CT performed after 24 h of symptom onset had SAH diagnosed, and two turned out to be aneurysmal. When CT was performed within 24 h of symptom onset it had a sensitivity of 100% (95% CI 95-100%), specificity of 98% (95% CI 96-99.7%), and NPV of 100% (95% CI 98-100%) in detecting SAH. Modern CT scanners seem to have high sensitivity and specificity in the diagnosis of SAH when performed within 24 h of symptom onset. Beyond this point, CT seems to lack sensitivity and further investigation with LP is required.
Subject(s)
Spinal Puncture/methods , Subarachnoid Hemorrhage/therapy , Tomography, X-Ray Computed/standards , Adolescent , Adult , Aged , Aged, 80 and over , Cohort Studies , Female , Finland/epidemiology , Head/diagnostic imaging , Headache/etiology , Humans , Male , Middle Aged , Retrospective Studies , Sensitivity and Specificity , Spinal Puncture/standards , Subarachnoid Hemorrhage/diagnosis , Subarachnoid Hemorrhage/epidemiology , Tomography, X-Ray Computed/methodsABSTRACT
In Finland, there has been a need to develop emergency care in the past years because of the government's statutes and the need to meet the international standards. Emergency medicine as a newcomer specialty has encouraged the process. Emergency physicians are expected to take more responsibility of patient flow and treatment in the emergency departments (ED). The observation unit is an important part of the ED. It allows patients to be treated on a short-term basis, and patient care is efficient due to the close communication between specialties. Patient selection is in the essence of a well-functioning observation ward.
