- Authors:
- Subtitle:
- intra- and interobserver agreement and relation to angiographic vasospasm and mortality
- DOI:
- 10.1093/bja/aes458
- Abstract:
- BACKGROUND: /st>Transcranial Doppler measurements of the middle cerebral artery flow velocity are widely used as an indicator of vasospasm after aneurysmal subarachnoid haemorrhage (SAH). We investigated inter- and intraoperator agreement in SAH patients and healthy volunteers using colour-coded transcranial Doppler (TCCD), with the secondary aim of describing prediction of angiographic vasospasm and mortality. METHODS: /st>Sixty patients and 70 healthy controls were each examined in duplicate by alternating operators. A total of 939 measurements divided on 201 examination sets were conducted by four observers. The Bland-Altman limits of agreement (LoA) were calculated using a variance components analysis. Angiography was performed on clinical indication and survival recorded at 30 days. RESULTS: /st>Differences between measurements increased with increasing average, and therefore, we analysed log-transformed values. Thus, LoA are given as ratios between measurements. There were no systematic intra- or interobserver differences (bias). The intraobserver LoA was 0.62-1.61 in patients and 0.67-1.50 in controls. However, they were 0.55-1.82 in patients with angiographic vasospasm, whereas in patients without, they were 0.66-1.52. The interobserver LoA was 0.55-1.81 in patients and 0.65-1.55 in controls, while in patients with and without angiographic vasospasm, they were 0.45-2.22 and 0.60-1.67, respectively. Flow velocity measurements day 6-10 were positively associated with 30 day mortality risk (P=0.02, logistic regression). CONCLUSIONS: /st>TCCD measurement variability is wider in patient measurements than in controls. This discrepancy can largely be explained by a higher degree of error in patients with angiographic vasospasm. Despite the considerable measurement variability in TCCD, values are predictive of outcome in SAH.
- Type:
- Journal article
- Language:
- English
- Published in:
- British Journal of Anaesthesia, 2013, Vol 110, Issue 4, p. 577-85
- Keywords:
- Adult; Aged; Aged, 80 and over; Algorithms; Angiography, Digital Subtraction; Cerebral Angiography; Cerebrovascular Circulation; Female; Forecasting; Humans; Male; Middle Aged; Middle Cerebral Artery; Observer Variation; Prospective Studies; Subarachnoid Hemorrhage; Tomography, X-Ray Computed; Ultrasonography, Doppler, Transcranial; Vasospasm, Intracranial; Young Adult; Journal Article; Research Support, Non-U.S. Gov't
- Main Research Area:
- Medical science
- Publication Status:
- Published
- Review type:
- Peer Review
- Submission year:
- 2013
- Scientific Level:
- Scientific
- ID:
- 239881902