Letter to the editor

Marion Zock, ,

Other Contributors:

December 07, 2010

Sir,

We congratulate Mueller et al. investigating the usefulness of serum protein S-100B to save cranial CT resources in the management of patients with minor head injury [1]. Although we definitely support their conclusions about the usefulness of protein S- 100B, two major concerns regarding the methodology of their study ought to be considered: Firstly, despite the well-described diagnostic time frame of S-100B as a screening tool in minor head injury [2, 3, 4], the authors interpreted the results of two patients false negative. However blood sampling of both patients was 11.5 and 48 hours subsequent to the incident far beyond recommended time frame to rule out traumatic brain injury, which was also mentioned by the authors themself in their discussion section. Therefore we completely agree with the authors' recommendation to ensure blood sampling for S-100 B as a screening tool within a maximum of 3 hours following the incident. If S-100B cannot be measured within 3 hours, it should not be considered to exclude traumatic brain injury [3]. Secondly, the authors found one patient with a skull fracture not been detected by serum S-100B. The patient was therefore interpreted as false negative as well. However protein S- 100B is a brain-specific serum protein to detect traumatic brain injury not skull fractures. Compared to missed or delayed diagnosis of traumatic brain injury, isolated asymptomatic skull fractures do not progress and rarely endanger patients' health. Acknowledging these circumstances, the sensitivity and the negative predictive value of serum-S100B would be 100%. Therefore the authors' conclusions may mislead clinicians considering the implementation of S- 100B to manage patients with minor head injury in the emergency department. Clinicians intending serum protein S-100B as a screening tool for decision making in adult mild traumatic brain injury in the acute setting should be familiar with its capabilities and limitations. If those are considered, S-100B is able to reduce the number of cranial CT by 30% [4].

Yours sincerely,

M. Zock, Chirurgische Klinik und Poliklinik, Campus Innenstadt, Klinikum der Universitaet Muenchen, Germany

Dr. B.A. Leidel, MD, Interdisziplinaere Rettungsstelle und Notfallaufnahme, Campus Benjamin Franklin, Charite - Universitaetsmedizin Berlin, Germany

References:

1. Mueller B, Evangelopoulos DS, Bias K et al. (2010) Can S-100B serum protein help to save cranial CT resources in a peripheral trauma centre? A study and consensus paper. Emerg Med J. DOI:10.1136/emj.2010.095372

2. Townend W, Dibble C, Abid K et al. (2006). Rapid elimination of protein S-100B from serum after minor head trauma. J Neurotrauma. 23(2): 149-155

3. Jagoda AS, Bazarian JJ, Bruns JJ et al. from the American College of Emergency Physicians and Centers for Disease Control and Prevention (2008). Clinical Policy: Neuroimaging and decision making in adult mild traumatic brain injury in the acute setting. Ann Emerg Med. 52: 714-748

4. Biberthaler P, Linsenmeier U, Pfeifer KJ et al. (2006). Serum S- 100B concentration provides additional information for the indication of computed tomography in patients after minor head injury: a prospective multicenter study. Shock. 25(5): 446-453

Conflict of Interest:

None declared

Conflict of Interest

None declared