Purpose
Prehospital estimation of injury severity is essential for prehospital therapy, deciding on the destination hospital and the associated emergency room care. The aim of this study was to ...compare prehospital estimates of the abbreviated injury scale (AIS) and the Injury Severity Score (ISS) by emergency physicians with the values of AIS and ISS of injury severity determined at the conclusion of diagnostics.
Methods
In this prospective study, the ISS was determined prehospital by emergency physicians. The validated AIS and ISS were analyzed based on final diagnoses. A Bland–Altman plot was used in analyzing the agreement between two different assays as well as sensitivity and specificity were determined. Confidence intervals were calculated for a Wilson score. Significance level was set at p ≤ 0.05.
Results
The prehospital ISS was estimated at 26.0 ± 13.0 and was 34.7 ± 16.3 (
p
< 0.001) after in-hospital validation. In addition, most of the AIS subgroups were significantly higher in the final calculation than preclinically estimated (
p
< 0.05). When analyzing subgroups of trauma patients (ISS < 16 vs. ISS ≥ 16), we were able to demonstrate a sensitivity of > 90% to identify a multiple-trauma patient. Diagnosing a higher injury severity group (ISS ≥ 25), sensitivity dropped to 61.1%. The Bland–Altman plot demonstrates that injury severity is underestimated in higher injury levels.
Conclusion
Multiple-trauma patients can be identified using the ISS. Anatomic scores might be used for transport decisions; however, an accurate estimation of the injury severity should also be based on other criteria such as patient status, mechanism of injury, and other triage criteria.
The purpose of this study was to evaluate the diagnostic value of MRI for detecting intracarpal lesions in clinical routine.
In a retrospective study, we reviewed the charts of 506 patients who had ...undergone wrist arthroscopy in our department between May 1998 and November 2002. Out of 506 patients 217 had an MRI. The MRI was performed at 31 different radiology facilities using a number of techniques. The MRI results were compared with the arthroscopic findings, taking the arthroscopic results as a "gold standard" (sensitivity = SEN, specificity = SPE, positive predictive value = PPV, negative predictive value = NPV, accuracy = ACC).
The following results were found: For tears of the scapholunate ligament the avalues are SEN 18.5 %, SPE 95 %, PPV 71 %, NPV 66 %, ACC66 %. Not one of 16 tears of the lunotriquetral ligament was found by MRI.
In our data we found a low sensitivity for unspecific requested and implemented MRI for detecting intracarpal lesions. Therefore the indication for MRI should only be made after experienced hand surgeons have examined the wrist. In our opinion, only direct MR-arthrography is equal to arthroscopy, so that only an experienced radiologist who is familiar with this technique should perform the MRI diagnostics of the hand.
On greibach normal form construction Urbanek, Friedrich J.
Theoretical computer science,
1985, 1985-00-00, Letnik:
40, Številka:
2-3
Journal Article
Recenzirano
Odprti dostop
In this note we present a procedure to rewrite a given Chomsky normal form grammar in Greibach normal form (GNF). This procedure yields the same grammar as the well-known procedure of Rosenkrantz, ...but is based on pure derivation-oriented reasoning and not on systems of equations.
On Greibach normal form construction Urbanek, Friedrich J.
Theoretical computer science,
1986, 1986-00-00, Letnik:
44, Številka:
2
Journal Article
Recenzirano
Odprti dostop
We present an algorithm which, given an arbitrary ε-free and chain-free context-free grammar, produces an equivalent context-free grammar in Greibach normal form (GNF). This algorithm is a ...generalization of an algorithm recently presented by Ehrenfeucht and Rozenberg. Using this algorithm the well-known GNF construction of Rosenkrantz can be obtained. Furthermore it is possible to rewrite a given context-free grammar by a GNF grammar which has at most twice as much nonterminals as the original grammar. This result is shown to be optimal (with respect to the number of nonterminals).
A theory of infinite linear systems and their solutions is developed.
For any commutative semiring families of formal power series are introduced, which are generalizations of the one counter ...languages. These families are characterized in two ways:
1.
(i) by solutions of infinite linear systems with a certain periodic structure;
2.
(ii) by solutions of finite algebraic systems with a certain form given by matrix equations.
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