DIAGNOSTICS OF CRANIOCEREBRAL AND EXTRACRANIAL DAMAGES IN POLYTRAUMA FROM THE STANDPOINT OF EVIDENCE-BASED MEDICINE
North Western Medical Research Center,
Saint Petersburg, Russia
The world rate of polytrauma shows a trend to increase. Therefore, its research has been obtaining the significance, because of the high mortality and disability. The term polytrauma means a severe concomitant or multiple injuries, which are accompanied by disorders of vital functions [1-6]. The modern concept of management of polytrauma at all stages consists in rendering medical assistance with adequate volume and rate and overtaking the development of some pathologic processes in the organs and the systems of the patient. In such conditions the significance of timely diagnostics of injuries in polytrauma significantly increases [1-5, 7-10]. It is known that the most informative methods for identification of different injuries are helical computer tomography (HCT) and magnetic resonance imaging (MRI) [4, 7-12]. However the literature gives little attention to the features of clinical and radial diagnostics of traumatic brain and extracranial injuries in polytrauma on the basis of evidence-based medicine [7, 9, 11, 13, 14].
Objective – to investigate the features of diagnostics of craniocerebral and extracranial damages in polytrauma from the standpoint of evidence-based medicine. According to the stated objective the following tasks have been developed: 1) to analyze the clinical features of polytrauma with orientation to development of various cerebral and somatic pseudosyndromes, 2) to define the features of choice of radial techniques for polytrauma, 3) to estimate the diagnostic information capacity of various diagnostic techniques in acute and subacute period of traumatic disease.
MATERIALS AND METHODS
The retrospective analysis included the clinical radiologic data of 1,903 patients with polytrauma who received their treatment within 2012-2014. Most patients (71 %) were the men. The most common causes of injuries were road traffic accidents (52 %); among them > 70 % – pedestrians. Without entering the admission department, all patients were admitted to the intensive care unit. Here the primary concilium including the intensivist, the surgeon, the traumatologist and the neurosurgeon was carried out. The resuscitation measures were realized simultaneously with medical diagnostic manipulations and included ultrasonic examination (USE) of the brain (echoencephaloscopy – echoES), the chest, the abdomen and the retroperitoneal space, cranial and facial radiology, X-ray examination of extremities, of various departments of the spine and the pelvis, HCT, and, if necessary, low invasive surgical interventions such as thoracocentesis and laparocentesis, skeletal traction, joint puncture and primary surgical preparation of wounds. The volume and the characteristics of the examination depended on intensity of disorders of the vital functions, the degree of traumatic shock and depression of consciousness according to Glasgow Coma Scale (GCS).
The radiologic study was performed with the digital X-ray device with two X-ray tubes “Easy Diagnost Eleva” (Philips), the telecontrolled digital radial diagnostic device CRT-OCO and ARTs-1 PS (Electron) and with use of the radial diagnostic mobile device S-duga RTS 612 (Electron). The radial examination was realized with the computer tomographic devices Aquilion 64 and Aquilion 16 (Toshiba), Brilliance 6S (Philips), 1.5 T magnetic resonance tomographic devices Signa Exite (GE), Excelerat Vantage Atlas (Toshiba), Intera (Philips), and the multifunctional ultrasonic scanners EUB 5500 (Hitachi) and Vivid S6 (GE).
The statistical analysis of the data was realized with Statistica 7 software (StatSoftInc) for Windows XP. During the statistical analysis we calculated the extensional coefficients (%), which characterize the relationship between the members and the integral, as well as mean arithmetic values (M) and mean errors in mean arithmetic (m) in the set of variate values. The probability of an erroneous declination of the null hypothesis was tested with χ2 test. The difference was reliable with p < 0.05. During the statistical analysis the efficiency of the radial methods was examined. The information capacity of the diagnostic techniques was evaluated with the common objective parameters: sensitivity, specificity and diagnostic accuracy [11, 13, 14].
RESULTS AND DISCUSSION
The injuries to more than two anatomic regions were in 818 cases (43 %), traumatic shock of various degrees – in 1,275 cases (67 %). After the preliminary examination we estimated some dominating characteristics of the injuries (table 1) and necessity for additional examinations (table 2).
| Table 1 | ||||||
| Distribution of patients according to dominating injuries (n = 1,903) | ||||||
| Table 2 | ||||||
| Distribution of patients according to type of examination (n = 1,903) | ||||||
X-ray examination was a commonly used method because of the polytrauma cases included the significant percentage of fractures of the upper and lower extremities as dominating injuries (18 % of the patients). Among the ultrasonic techniques, echoES was used in almost all cases. Ultrasonic examination was used for closed chest, abdominal and retroperitoneal injuries. MRI was used in 83 % of the cases with the subacute period of traumatic disease (3-4 days after an injury).
After the preliminary examination the dominating characteristics of the injuries and the need for additional examinations were evaluated. Most cases (56 %) were head injuries with TBI and craniofacial injuries of various severity.
In 84 % of the cases with polytrauma with consciousness disorders (GCS = 5-8), severe TBI and the extracranial injuries (internal organ injuries, i.e. the chest, abdomen, the retroperitoneal space, as well as the extremities) were identified. Because development of the syndromes of intermutual burdening and overlapping we identified the appearance (11 %) of some clinical signs of the pseudocerebral syndromes, which imitate compression and dislocation of the brain, and in 12 % – the pseudosomatic syndromes imitating injuries to the chest and/or the abdomen. The conducted studies with definition of Pearson’s coefficient (r) identified that development of pseudosyndromes was in the close correlation relationship with intensity of traumatic shock and consciousness disorders according to GCS (r = 0.8). Because of some features of the clinical course of polytrauma within 3 hours after admission some injuries were not identified in 19 %: fractures of the cranial vault and the cranial base, multiple fractures of the ribs and the scapula, lung contusion and hemothorax.
Complex HCT examination including the brain, the fascial skeleton, the thoracic and cervical spine, thoracic organs and pelvic bones was performed in 23 % of the patients including 7 % of the cases with additional abdominal CT. For providing low additional injuries the patients were placed onto the tomographic table only once (for any number of examinations).
Multiple injuries to the head or craniofacial injuries consisted 9.8 % of the cases from the general percentage of the patients with polytrauma. Severe facial skeletal injuries present an absolute indication for X-ray examination, which is insufficiently informative because of complex anatomic structure of this region. Among the patients with severe concomitant TBI with development of intracranial hematomas 13 % of the cases were associated with multiple (in one or two cerebral hemispheres) intracranial hematomas, which created impossibility for diagnostics with use of echoES or clinical examination. Because of simultaneous injuries to multiple anatomic regions, polytrauma creates the necessity for the diagnostic techniques, which give maximal information about the patient and allow rapid diagnostics of life-threatening injuries. Therefore, during the process of stabilizing vital functions with consideration of characteristics of injuries and clinical data we performed HCT for the head, the cervical and thoracic spine, the thoracic and abdominal cavities and the pelvis. We carried out HEC for the brain and the cervical spine with section thickness of 3 mm, the pitch 0.417 (for the spiral mode), the thickness of the reconstructive section was 2.5 mm. After that, if necessary, the standard radial examination of the extremities was made. According to the results of the present study and other studies, such examination gives the highest information capacity for such injuries [1, 2, 4, 6, 7].
1,903 patients with polytrauma received 1,332 surgical interventions (70 %), moreover, for each fifth patient – with correction of cerebral compression, and for each eighth patient – with correction of lung compression syndrome (table 3). During cranial trepanation (bone plastic or resection trepanation) we removed some substrates compressing the brain: depressed fractures of the cranial vault (7 %), intracranial hematomas (45 %), subdural cerebrospinal fluid hydrome (5 %), cerebral crush injuries (9 %) and combinations of various factors (34 %). Reposition and fixation of facial skeletal fractures was performed on the upper (53 %), mean (24 %) and lower (13 %) facial regions, and in various combinations (10 %).
| Table 3 | ||||||
| Distribution of patients according to type of surgical treatment (n = 1,347) | ||||||
508 patients died at various time intervals after their injuries. The mortality rate was 26.7 %. The main causes of lethal outcomes were concomitant injuries accompanied by shock and blood loss (30 %), severe TBI with edema and brain dislocation (27 %), and complications of traumatic diseases (mostly bilateral pneumonia and multiple organ dysfunction syndrome).
The study showed that the information capacity of HCT significantly increased after injuries to several anatomic regions, especially, in concomitant spine and spinal cord injuries. It is known that about 10-20 % of cervical injuries are not identified by means of X-ray images. The information capacity of HCT for isolated cervical injuries is at least 60 % [7, 10]. The results of the study show that the mean time for head or cervical HCT examination for one patient was 14.5 ± 3.5 min.
The table 4 shows the diagnostic information capacity of the examination techniques, where Se – sensitivity, Sp – specificity, Ac – accuracy, PPV – positive predictive value, NPV – negative predictive value.
| Table 4 | |||||
| Diagnostic capacity of examination techniques in polytrauma | |||||
The results of the study showed that HCT was the main method for early diagnostics of concomitant TBI. The method allows rapid identification of characteristics, location and the number of injuries of cranial bones, facial skeleton and the brain. The table 4 presents the diagnostic information capacity of plain X-ray imaging in researching all anatomic regions. One should note that fractures of extremities significantly increased the values of sensitivity, specificity and accuracy of the X-ray technique (73.6 %, 75.4 % and 76.3 % correspondingly). It is noteworthy that the most severe complicated intraarticular injuries to extremities in 89 % of the cases were associated with coincidence of the results of digital radiological and tomographic examination. Only in 11 % of the cases the X-ray examination did not show any bone traumatic changes in full volume, especially for joint injuries with significant amount of small bones.
The results of the study show that the whole process of HCT examination of the head, the cervical, thoracic and abdominal departments and the pelvis takes 30.5 ± 3.5 min on the average including time for delivering a patient (45 % from the above mentioned time), image acquisition (35 %) and treatment of data (20 %) including frontal and sagittal reconstructions. High operating rate of multispiral scanners and the available algorithms of artefact suppression significantly increased diagnostic significance of images for polytrauma. HCT is allowed during resuscitation measures. Therefore, in clinics of emergency aid the scanners should be installed directly in admission departments or in the intensive care unit (anti-shock unit).
HCT is considered as the obligatory method for day and night examination for patients with polytrauma. For severe TBI with deep disorders of consciousness it is advisable to conduct radial examination including the head, the cervical spine, thoracic organs and the pelvis. Higher information values of MRI are neutralized by long duration of the examination in acute period of polytrauma.
DISCUSSION
Computer tomography has not receded into the background in view of fast development of MRI, despite of some predictions. It is conditioned by multiple causes. Firstly, HCT is more available and cost effective in comparison with MRI. Secondly, it is characterized with some favorable conditions of examination and significantly lower time of scanning for agitated patients and patients with polytrauma. Significant importance is associated with continuous technical improvement of multidetector (helical) CT with improvement of spatial and time resolution, multidimensional presentation of images and reconstructions. Additional software allows significant extension of possibilities of HCT in angiology (perfusion and HCT-angiography). As result, at the present time HCT is permanently used for multiple tasks such as the primary and additional visualizing method, and it is still an integral part of examination [3, 4, 7, 10, 11].
Radial examination for polytrauma takes the leading place in diagnostics of characteristics and severity of injuries. Among polytrauma cases, head injuries (TBI and craniofacial injuries) appear more often than injuries in other anatomic regions. According to the results of the presented sample, head injuries were in 56 %. Early diagnostics of characteristics and severity of TBI with subsequent adequate complex treatment including surgical interventions should be referred to the most important factors favoring improvement in outcomes in such patients.
Therefore, the clinical features of polytrauma are development of syndromes of mutual burdening and overlapping, various cerebral and somatic pseudosyndromes that significantly aggravate confirmation of diagnosis. The features of choice of radial methods for polytrauma are advisability of using HCT owing to combination of low duration (about 30.5 ± 3.5 min) and high information capacity (sensitivity – 95.2 %, specificity – 95.8 %, accuracy – 95.6 %), and suspected injuries to extremities – X-ray imaging (sensitivity – 73.6 %, specificity – 75.4 %, accuracy – 76.3 %). MRI examination gives the highest diagnostic information capacity, especially in injuries to the brain and the spinal cord. Also its administration is advisable in subacute period of traumatic disease.
CONCLUSION
1. The clinical features of polytrauma are development of syndromes of mutual burdening and overlapping, various cerebral and somatic pseudosyndromes which significantly complicate confirmation of diagnosis. The degree of intensity of pseudosyndromes is directly related to the level of disorder of consciousness and traumatic shock.
2. The peculiarities of choice of radial techniques for polytrauma are appropriateness of HCT as the obligatory method owing to combination of low duration of the examination (30.5 ± 3.5 min) and high information capacity (95.2-95.8 %); in suspected injuries to extremities X-ray imaging is used (73.6-76.3 %). Echoencephaloscopy and general craniography are not enough informative for traumatic brain injuries.
3. MRI-examination, especially in cerebral and spinal cord injuries, is characterized with the highest diagnostic significance. However its use is appropriate in subacute period of traumatic disease.