Neurology India, Vol. 59, No. 5, September-October, 2011, pp. 739-742
Initial experience with mobile computed tomogram in neurosurgery intensive care unit in a level 1 trauma center in India
Deepak Agrawal, Siddhartha Sahoo, GD Satyarthee, Deepak Gupta, Sumit Sinha, MC Misra
JPN Apex Trauma Centre, All India Institute of Medical Sciences, New Delhi, India
Keywords: Head injury, intensive care unit, mobile computed tomogram
Neurosurgical patients, in particular patients with severe head injury require frequent computed tomograms (CTs) of the head, often at a short notice. As most of these patients are ventilated with multiple infusion lines, it is a difficult task shifting them for CT scan. Also, while shifting, mishaps such as endotracheal tube dislodgement, ventilator failure, and/or oxygen supply issues can occur. Availability of a mobile CT in the intensive care unit (ICU) may prove to be invaluable for such patients. ,,,,, This study reports the usefulness of mobile CT in a Neurosurgical ICU (NICU) at a Level 1 Trauma Center in India.
Materials and Methods
This review was carried out over a 9-month period (18 July 2009 to 30 April 2010) at our center after the installation of a mobile CT scanner (Ceretom® NeuroLogica Corporation, Boston, MA, USA) in the NICU [Figure - 1] and [Figure - 2]. Administrative and clinical data were reviewed and analyzed. For the first 6 months, only the number of CTs done was available. Prospective data collected from January to April 2010 included Glasgow Coma Scale (GCS) score, ventilator status, and ionotropic support (dopamine and noradrenaline) at the time of CT scan.
A total of 1292 head CTs were done during the study period with an average of 4.78 CT scans per day. Of the 563 patients in whom prospective data was available, 456 (81%) patients were on ventilator, 450 (80%) patients were on sedation, and 37 (6.5%) patients were on ionotropic support at the time of doing CT scan. Five patients had isolated head injury and hypotension at admission and CT head showed brainstem hemorrhage in three patients. The mean GCS score at the time of doing CT was 8.1 (range 3-15). The average time taken to do CT scan [from the time of request to transmission into picture archiving and communication system (PACS)] was 12.6 min (range 7.8-47 min). There were no adverse events in any of the patient while doing the mobile CT. Four patients could be taken up for immediate reoperation because of contralateral expanding epidural hematoma (EDH) or operative site hematoma as seen on early postoperative mobile CT.
Image quality was judged to be excellent by all neurosurgical faculty in the ICU [Figure - 3]. During the study period, the main CT scanner broke down four times (for variable time periods) and the mobile CT scanner could manage the load of severe head injured patients in the casualty without any issues. The mobile CT machine itself broke down 36 times and the mean response time was 12.5 h (range 1-144 h) during each breakdown period.
The total cost of the mobile CT was Rs 20,000,000 (which included a 5-year comprehensive maintenance contract) and for the 5 th to 10 th year, the maintenance contract was fixed at Rs 800,000/year (including the tube of the machine). Thus the total cost of the machine was Rs 24,000,000. Extrapolating our data of 1292 head CTs in 9 months, 1723 CTs would be done yearly (17,230 CTs over 10 years). The average cost per CT works out to be Rs 1393.
In spite of major advancements in imaging of the brain, non-contrast head CT remains the gold standard for management of head trauma. The usefulness of serial CT scans in patients with head injury remains invaluable and repeat head CT scan is often required to determine the causes for the neurologic deterioration. , Patients with severe head injury require ventilation, intracranial and other physiological monitoring and sedation. All this require multiple lines. It will be a major task to transfer such patients for CT scan to the radiology department. It is not uncommon to have some mishaps while doing such transfers. Such transfers also require additional manpower.  In such a scenario, availability of a mobile CT scan proves to be invaluable as shown in this study.
Mobile CT scan has also improved patient management in the NICUs. Previously, patients who are hemodynamically unstable are considered unsuitable for shifting for CT scan. However, with the availability of mobile CT scan, one can sean such patients safely. In our study, 6.7% of the patients were on ionotropic support at the time of mobile CT scan. Five patients in our study with isolated head injury had hypotension and in three of these patients, mobile CT scan showed brainstem hemorrhage, thus helping in establishing the diagnosis and also determining the prognosis. Mobile CT scan may help in determining the causes for unexplained neurologic deterioration in the immediate postoperative period. In our study because of the availability of mobile CT scan four patients could be taken up for immediate reoperation for contralateral expanding EDH or operative site hematoma.
The most important aspects to assess while using a mobile CT are the image quality and the ease of use. In spite of being an 8-slice scanner, all neurosurgical faculty termed the image quality as "excellent." Also, the average time taken to do a CT scan (from the time of request to transmission into PACS) was 12.6 min (range 7.8-47 min), which makes it a true "bedside" tool, which can dramatically improve decision-making and patient care.
In spite of the major advantages of the mobile CT scanner, there remain issues with uptime of the scanner. Presently, in India, there is only one distributor and there are only few installations., Support and service leave much to be desired. During the study period, the CT machine broke down 36 times and the mean response time was 8.5 h (range 1-144 h) during each breakdown. These issues emphasize the need for optimization of service and support.
Due to the small bore of the machine, the mobile CT can perform CT of the cervical spine up to C3 vertebral level and occasionally up to the C4 vertebral level in adult patients. The limiting factor is usually the shoulders of the patient. Although useful for high cervical trauma, the mobile CT is not useful for majority of the cervical spine injuries. In infants, however, the mobile CT may be able to do a whole body scan without any problems. Another issue relates to radiation exposure to surrounding personnel and patients.  As per radiation data on file and given by the company, one can stand as close as 3 m without needing to wear a lead apron. However, safety needs to be borne in mind while doing the CT scans. The cost factor may also be a major issue as smaller hospitals and neurosurgical units may not find it a very cost-effective proposition.
Copyright 2011 - Neurology India
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