Editorial: traumatic brain injury and postoperative CT.

The classic teaching of neurosurgery residents has always emphasized the importance of the neurological examination in medical decision making. This is particularly true when deciding whether the postoperative patient requires an unplanned return to the operating room. The threshold for a return to the operating room to evacuate a hematoma or correct an unforeseen surgical issue is necessarily high, because such a return significantly increases the risk of untoward outcomes. It is therefore not terribly surprising that the analysis of the institutional experience in a large cohort of patients presented in the accompanying paper by Fontes et al.1 should find that no patient whose neurological examination demonstrated either no deficit or an expected deficit required additional, unplanned neurosurgical procedures. In other words, a routine postoperative head CT scan appeared to have no additional value in the absence of an unexpected neurological deficit (that would have ordinarily prompted an imaging study anyway). Fontes et al.’s findings add to a growing body of evidence that supports a reduction in the reliance on routine postoperative imaging. The authors argue that the added cost of such studies, as well as the incremental radiation risk, is simply not justified by the data. Although this study should provide a level of comfort for neurosurgeons trying to reduce their reliance on routine radiological imaging in the postoperative patient, it is important that the limitations of this study be kept in mind. First and foremost, the patient cohort reported here was treated in a large, busy, and well-staffed academic medical center. This may not reflect the resources available in other health care environments. A smaller hospital with fewer dedicated neurosurgical staff available to care for these patients may need to rely more on rotating staff, who may have less experience in detecting and managing changes in the neurological examination. In these smaller hospitals, CT scans may have greater utility in alerting staff to patients with a higher risk of deterioration. In addition, it is important to keep in mind the retrospective nature of this study. Interpretation of neurological findings, done retrospectively, may well influence how patients were grouped. This type of bias may easily affect the findings of the analysis and cannot be avoided, despite the best intentions of the authors. Finally, the definition of relevant neurosurgical intervention used by the authors excluded such procedures as repositioning of ventricular catheter tips based on imaging findings. It may be argued that patients who had such minor interventions were spared more significant sequelae as a result. Obtaining a CT scan that in retrospect does not appear to influence the management of the patient is very different from not doing the study in the first place. The authors of this study are to be commended for performing a detailed analysis of their large experience, and for documenting it thoroughly and thoughtfully. They do provide the reader with food for thought. However, despite the findings of this study, I suspect that routine postoperative CT scans will continue to be performed. In an era of high patient acuity and increasing prevalence of work-hour restrictions and handoffs, there is a greater potential that the significance of a neurological finding would be lost in the postoperative course. A patient who is initially only slightly drowsy after emerging from an anesthetic could be cared for by a series of physicians and midlevel providers who were previously unfamiliar with the patient, and who may miss a slow deterioration in the patient’s sensorium. Although this study argues that this has not been the case in a large institutional cohort, the retrospective nature of the data may have influenced how patients were grouped. Only a large, prospective study could answer the question of the utility of routine head CT scans definitively. One could argue that the performance of routine CT scans is partly a reflection of the advent of faster and more portable CT equipment, and partly a response to the pressures posed by the increasing “rotation” of the medical team caring for the postoperative patient. It provides the medical team with objective data on the patient’s status easily transportable from one practitioner to the next. Whether or not this is borne out in reality, routine scanning appears to protect the patient from the increasingly fragmented nature of the medical team in the immediate postoperative period. Although data from the Rush University study argue that this protection is more virtual than real, I suspect that this practice will continue for some time to come. (http://thejns.org/doi/abs/10.3171/2014.2.JNS14380)