versión impresa ISSN 1130-1473
LOBATO, R.D. et al. Value of serial CT scanning and intracranial pressure monitoring for detecting new intracranial mass effect in severe head injury patients showing lesions type I-II in the initial CT scan. Neurocirugía [online]. 2005, vol.16, n.3, pp.217-234. ISSN 1130-1473.
Objective. To determine the incidence of pathological and intracranial pressure (ICP) changes during the acute posttraumatic period in severe head injury patients presenting with lesions Types I-II (TCDB classification) in the admission CT scan with the aim of defining the most appropriate strategy of sequential CT scanning and ICP monitoring for detecting new intracranial mass effect and improving the final outcome. Material and methods. 56 patients (ages 15-80 years) consecutively admitted during a 2 years period were included. All had the initial CT scan < 24 hours after injury (mean interval = 150 min), several CT controls within the first days of the course and ICP monitoring after admission. Different epidemiological, clinical and radiological variables were recorded and deterioration defined as the development of sustained ICP over 20 mmHg requiring aggressive medical and/or surgical treatment was considered the dependent variable. Uni and multivariate analyses were made for determining the correlation between different parameters and the occurrence of deterioration and the final outcome as assessed with the GOS. Results. The mean GCS score was 5 and 37% of the patients showed pupillary changes; 52.3% had peritraumatic hypotension-hypoxemia, 16.1% anemia and 12.3% coagulation changes. 50% of the patients showed petechial hemorrhages in the white matter or the brainstem, 66% SAH, 40% HIV, 39.3% brain contusion and 21.4% small extraxial hematomas. 57.1% of the patients showed CT changes through the acute post-traumatic period consisting of new contusion (26.8% of the cases), growing of previous contusion (68.2%) or previous extraaxial hematoma (10.7%), and generalized brain swelling (10.7%). 64.9% of the patients made a favourable and 35.7% an unfavourable outcome. Overall, 27 (48.9%) patients developed deterioration, 21 (37.5%) with concurrent CT changes and 6 (10,7%) without new pathology as seen by the CT control. The remaining 29 (51.7%) patients in this series did not develop deterioration in spite that 11(19.6%) showed CT changes. The age, the initial score, the occurrence of peritraumatic hypotension-hypoxemia and coagulation disorders did not correlate with the risk of deterioration. By contrast, the presence of contusion at the initial CT scan (p= 0.01) and the occurrence of CT change (only generalized brain swelling, p= 0.003) significantly correlated with the risk of deterioration; in his turn deterioration increased by a factor of 10 (OR = 9,8) the risk of death and 7 out of the 8 patients who died developed intractable intracranial hypertension. The 8 (14.2%) patients requiring surgery showed simultaneous ICP deterioration and CT changes, but another 11 patients in a similar condition could be managed without surgery. With or without ICP deterioration, patients showing CT changes had a worse outcome than those without new pathologies, but the difference did not reach statistical significance. Discussion and conclusions. Over 50% of the patients with initial Type I-II lesions developed new CT changes and nearly 50% showed intracranial hypertension during the acute posttraumatic period. Considering the high incidences of ICP and CT deterioration through the course, along with the absence of strong predictors and the discordances between CT and ICP changes (which were seen in 30.3% of the cases) we recommend ICP monitoring after admission in all patients and serial CT scanning at 2-4, 12, 24, 48 and 72 hours after injury with additional controls as indicated by clinical or ICP changes in all cases. Though it is clear that the presence of severe intracranial hypertension significantly increased the risk of death, the small size of the sample in this series prevented to assess to what extent the occurrence of new mass effect and/or raised ICP contributed to the development of moderate and severe disability in the survivors which were mainly due to the occurrence of diffuse axonal injury. Finally, demonstrating that sequential CT scanning and ICP monitoring improve the final outcome in this type of patients would require a prospective randomized trial which is impracticable for different reasons, among them the ethical ones.
Palabras clave : head injury; Postraumatic coma; Brain contusion epidural hematoma; Axonal injury; Computerized tomography; Intracranial pressure.