a b s t r a c t

Study Objective: The aim of this study is to determine if the introduction of a pan-scan protocol during the initial assessment for blunt Trauma activations would affect missed injuries, incidental findings, treatment times, radiation exposure. and cost.

Methods: A 6-month prospective study was performed on patients with blunt trauma at a level 1 trauma center. During the last 3 months of the study, a pan-scan protocol was introduced to the trauma assessment. Categorical data were analyzed by Fisher exact test and continuous data were analyzed by Mann-Whitney non- parametric test.

Results: There were a total of 220 patients in the pre-pan-scan period and 206 patients during the pan-scan period. There was no significant difference in injury severity or mortality between the groups. Introduction of the pan-scan protocol substantially reduced the incidence of missed injuries from 3.2% to 0.5%, the length of stay in the emergency department by 68.2 minutes (95% confidence interval [CI], -134.4 to -2.1), and the mean time to the first operating room visit by 1465 minutes (95% CI, -2519 to -411). In contrast, fixed computed tomographic scan cost increased by $48.1 (95% CI, 32-64.1) per patient; however, total radiology cost per patient decreased by $50 (95% CI, -271.1 to 171.4). In addition, the rate of incidental findings increased by 14.4% and the average radiation exposure per patient was 8.2 mSv (95% CI, 5.0-11.3) greater during the pan-scan period.

Conclusion: Although there are advantages to whole-body computed tomography, elucidation of the appropriate blunt trauma patient population is warranted when implementing a pan-scan protocol.

(C) 2016

Introduction

The use of pan-computed tomography (also known as a pan-scan, or PS) as standard of care for trauma activations is becoming more prevalent. However, many trauma centers still use selective computed tomography (CT) to assess patients with trauma. Selective CT is gener- ally directed by the trauma team leader and is based on the mechanism of injury, the physical examination findings, and the results of trauma bay imaging including plain film and a focused assessment with

? Disclosure: All authors declare no conflicts of interest and have no financial ties to disclose.

* Corresponding author at: Department of Emergency Medicine, Jamaica Hospital Medical Center, 8900 Van Wyck Expressway, Jamaica, NY 11418. Tel.: +1 718 206 6026;

fax: +1 718 206 6085.

E-mail addresses: [email protected] (M.K. James), [email protected] (S.D. Schubl), [email protected] (M.P. Francois), [email protected] (G.K. Doughlin), [email protected] (S.-W. Lee).

sonography for trauma. With the lower utility of CT scanning in pene- trating patients with trauma, the debate over the use of PS is isolated to patients of blunt trauma. There are often no obvious signs of injury in patients with blunt trauma, although the mechanism may suggest high risk. Pan-CT may be more appropriate in assessing blunt trauma in- juries [1].

At some trauma centers, a PS is routinely used as a diagnostic tool to identify traumatic injuries. Several European registry-based studies have identified and confirmed a decrease in mortality at centers where a PS is used. However, there are several concerns with the de- signs of these studies [2,3]. In addition, there has been increasing con- cern on whether or not the benefits outweigh the risks [4,5]. Patients subjected to PSs are exposed to a higher dose of radiation which can pose long-term cancer risk [6-8]. The increased use of PSs has also been critiqued due to its cost; however, there is insufficient evidence to conclude that using a PS as the standard of care for patients with trau- ma increases Total cost of care [9,10]. On the other hand, PSs can be ben- eficial to patients with trauma because it is considered more sensitive

http://dx.doi.org/10.1016/j.ajem.2016.09.027

0735-6757/(C) 2016

and accurate in detecting multiple injuries [11,12]. This may be an important factor in decreasing the mortality rate in severely injured pa- tients with trauma as it allows for early identification of injuries [13-17]. Some studies even demonstrate that a PS decreases the time it takes to identify injuries allowing for more timely treatment, and shorter stay in the emergency department (ED) and hospital [2,11,12,18]. In addition, some argue that contrary to the belief that PSs increase exposure to radiation, if a PS is performed early in the evaluation process, it may decrease the overall number of scans the patient receives and hence decrease the overall level of radiation exposure [2].

Moreover, a PS may identify unanticipated injuries, which may have been missed if only selective scanning was chosen. Asha et al [7] exam- ined missed injuries before and after the introduction of a PS protocol. There was no significant benefit to using a PS to detect missed injuries, however; the overall incidence of missed injuries was minimal [7]. An- other group attempted to determine if PSs were overused for patients with blunt trauma via surveys of emergency medicine physicians and trauma surgeons [19,20]. Before CT imaging, both groups were asked to predict the site of injury and choose between whole-body CT and selective CT. Whole-body scanning detected missed injuries, 0.3% of which needed immediate intervention, suggesting that pan-CT should be used for patients with blunt trauma [20].

At our institution, we used selective scanning as our standard of care for trauma activation patients. The aim of this study is to determine if implementing pan-CT as the standard of care for patients with trauma during the initial assessment would affect the number of missed injuries, radiation exposure, and hospital cost. Secondarily, we hypothesized that if PSs are used as part of the initial evaluation of all patients with blunt trauma, ED disposition, treatment, and/or discharge may be faster, thereby reducing cost of care.

Methods

Study design

This prospective study took place over a 6-month period in the ED at an urban, academic level 1 trauma center. Patients with blunt trauma who met criteria as trauma activations were included in the study. During the last 3 months of the study, a PS protocol was introduced during the initial trauma assessment as the standard of care for all blunt trauma activations. This study was approved by the institution’s review board, and patient consent was not required.

Standard evaluation of patients with trauma was performed, which included history, physical examination, anteroposterior chest and pelvis radiographs, and focused assessment with sonography for trauma. The PS protocol was developed with the assistance of the radiology depart- ment and introduced 3 months into the study. A PS included imaging of the head, cervical-spine, chest, and abdomen/pelvis. Imaging of the maxillary face was optional. Each CT scan was a separate protocol and a set of images generated as a no single-run PS protocol was designed. Head, maxillary face, and cervical-spine imaging was done without in- travenous contrast, whereas chest and abdomen/pelvis imaging was performed with contrast. Computed tomographic scans were read by the radiology attending and by an off-site radiology service during Off hours. All scans read off-site were confirmed the following day by the radiology attending. In all cases, the chief trauma resident and trauma attending reviewed the CT imaging and reports.

Setting

Jamaica Hospital has 3 tiers of trauma activation. Trauma activations are managed by a team consisting of an emergency physician, an at- tending trauma surgeon, a resident trauma team, an anesthesia attend- ing, a trauma program manager or nursing supervisor, a respiratory therapist, a radiology technician, social services, 2 ED registered nurses, and security. The trauma surgeon and the anesthesia attending are only

required to be present at tier 1 activations. For tier 2 activations, the chief trauma resident is required to be present, whereas the presence of the trauma surgeon and attending anesthesiologist is optional unless deemed necessary. Tier 3 trauma activations are consults evaluated by the trauma surgery resident and were not included in the study.

Selection of participants

All patients with blunt trauma older than 18 years who were treated as trauma activations during the study period were included. Patients were excluded if they were younger than 18 years, died in the trauma bay before CT scanning, pregnant, transferred directly to the operating room without CT scanning, or were downgraded from trauma activation status before CT scanning.

Identification of “missed injuries“

The final decision to image the patient was made by the trauma team leader, meaning the trauma surgeon or chief resident. Any injuries not detected in the initial scans ordered during trauma assessment but later identified were considered missed injuries. extremity injuries were excluded except for Proximal humerus and proximal femur inju- ries, which were considered missed if no chest or pelvis CT was ordered, respectively. Injuries that were clinically obvious or noted on plain film were not included. A trauma surgeon and ED attending independently reviewed electronic medical records to identify missed injuries. Missed injuries were categorized into minor and major. Minor was defined as injuries that would be generally manageable on an outpatient basis if they were found in isolation, whereas major was defined as an injury that in and of itself would require admission or operation.

Incidental findings

Incidental findings were defined as any unexpected finding not related to trauma. Exclusions included age-appropriate changes, mild degenerative joint disease, signs of previous surgery or trauma, and findings already known from previous imaging. Minor incidental findings were defined as findings that were clinically insignificant or findings not requiring intervention or follow-up within 30 days. Major incidental findings were defined as those requiring immediate intervention or follow-up within 30 days.

Other variables

Patient electronic medical records were reviewed for demographics, CT findings, and patient disposition. Age, sex, weight, height, Injury Severity Score (ISS; based on AIS 2005), Glasgow Coma Scale (GCS), mortality, initial pulse rate, initial respiratory rate, initial systolic blood pressure, and alcohol and drug use were obtained from the electronic medical records. Length of stay in the hospital, surgical intensive care unit (SICU), and ED were also recorded. Fixed costs were broadly defined as those that are unaffected by the patient volume, whereas variable costs change with volume, meaning that they would descend to zero with no patients. Cost data were obtained from our institution’s cost center database.

Radiation

radiation dose for each patient was obtained from the dose report for each CT scan obtained by the patient. Radiation doses were obtained for scans ordered during the trauma assessment and for scans ordered after the assessment including after hospital admission. The total dose length product (DLP; in mGy/cm) was used to calculate the effective dose (E; in mSv) using the formula E = DLP x k, where k is the tissue weighting factor based on the body region scanned. Based on the 2007 International Commission on Radiation Protection recommendations, the following k

values were used: head, 0.002; neck, 0.0059; chest, 0.014; and abdo- men, 0.015 [21]. The CT scanner (GE Optima CT660; GE Healthcare, Port Washington, NY) was unchanged during the study period.

Data analysis

To analyze data, GraphPad Prism 6 (GraphPad Software Inc, La Jolla, CA) was used, and P b .05 was considered significant. Categorical variables are expressed as count (n) and percent (%), and continuous variables are expressed as mean and SD or median and interquartile range where relevant. Significance testing was done using Fisher exact test on categorical variables. For continuous variables, the sample was first assessed for normality using the Shapiro-Wilk normality test followed by the Mann-Whitney nonparametric test. The Welch t test was used to calculate a 95% confidence interval (CI) for the difference between the means.

Results

Characteristics of study subjects

There were a total of 608 trauma activations during the 6-month study period. Penetrating trauma accounted for 121 of the activations, blunt trauma accounted for 484, and burns accounted for 3 trauma acti- vations. Of the 484 blunt trauma activations, 426 were eligible for study inclusion. A total of 220 (51.6%) patients were treated during the pre-PS period and 206 (48.4%) patients during the PS period. The mean (SD) age of the 426 eligible patients was 48.8 (21.5) years and 285 (66.9%) were male. Most patients (88.3%) had a GCS in the range of 12-15. A total of 50 (11.7%) patients required intubation in the trauma bay. The average (SD) length of stay, for the 270 (63.4%) admitted patients, was 4.5 (8.3) days. The median ISS was 4 (interquartile range, 1, 9) and the mortality rate was 2.8%. See Table 1 for additional details.

Main results

A total of 7 (3.2%) patients during the pre-PS period and 1 (0.5%) patient during the PS period had missed injuries. Only 1 injury was missed per patient. There was a 2.7% decrease in the number of missed injuries during the PS period vs the pre-PS period. Patients during the pre-PS period were 6.7 times (95% CI, 0.82-55.3) more likely to have a missed injury when compared with the patients in the PS period. During the pre-PS period, 3 (42.9%) of the missed injuries were considered major. Major injuries decreased to 0% during the PS period. The single missed injury during the PS period was considered minor. There was a 14.4% increase in the number of patients with incidental findings and the average number of incidental findings increased by 1.3 (95% CI, 0.8-1.8) during the PS period. Additional information is presented in Tables 2 and 3.

To determine if introduction of a PS protocol changed trauma management/outcome, varioUS time intervals were analyzed (Table 4). Introduction of a PS protocol increased the length of stay in the hospital by 1.3 days (95% CI, -0.33 to 2.88) and the SICU by 2.3 days (95% CI, -2.62 to 7.23). However, this increase was not significant. When patients were stratified based on an ISS N 8, there was still no significant difference in the length of stay. The average time spent in the ED was significantly reduced by 68.2 minutes (95% CI, -134.4 to -2.1) during the PS period when compared with the pre-PS period. Moreover, patients with an ISS N 8 spent substantially less time in the ED (-182 minutes; 95% CI, -326.4 to -37.63) during the PS period. The introduction of the PS protocol also significantly reduced the time to the operating room by 1465 minutes (95% CI, -2519 to -411). Detailed information is presented in Table 4.

The cost of implementing a PS protocol was also evaluated (Table 5). Introduction of the PS protocol decreased the average radiology cost per patient by $50 (95% CI, -271.1 to 171.4). However, the average cost of patient care increased by $4971 (95% CI, -1100 to 11 042) during the

Table 1

Characteristics of the eligible patients

Variable	n	All patients	Pre-pan-scan period (n = 220)	Pan-scan period (n = 206)
Age (y)	426	48.8 (21.5)	48.4 (21.2)	49.1 (21.8)
Male	426	285 (66.9)	135 (61.4)	150 (72.8)
Female	426	141 (33.1)	85 (38.6)	56 (27.2)
Weight (lb)	418	170.7 (38.6)	168 (36)	173.6 (41.1)
Height (in.)	408	66.9 (5.5)	66.2 (3.7)	67.7 (6.9)
BMI (kg/m2)	406	26.9 (5.3)	27.0 (5.0)	26.9 (5.6)
Initial respiratory rate	426	18 (4)	19 (5)	18 (3)
Initial pulse	426	89 (18)	90 (18)	88 (18)
Initial systolic BP (mm Hg	426	144 (27)	144 (26)	143 (29)
Initial GCS	426	-	-	-
3		19 (4.5)	3 (1.4)	16 (7.8)
4-7		7 (1.6)	6 (2.7)	1 (0.5)
8-11		24 (5.6)	12 (5.4)	12 (5.8)
12-15		376 (88.3)	199 (90.4)	177 (85.9)
Tier 1 activation	426	101 (23.7)	42 (19.1)	59 (28.6)
Tier 2 activation	426	325 (76.3)	178 (80.9)	147 (71.3)
Alcohol use	401	133 (33.2)	74 (33.6)	59 (28.6)
Drug use	275	26 (9.4)	4 (2.7)	22 (10.7)
Intubated in trauma bay	426	50 (11.7)	22 (10)	28 (13.6)
ED disposition	426	-	-	-
Admitted		270 (63.4)	131 (59.5)	139 (67.5)
Floor		179 (66.3)	90 (68.7)	89 (64)
SICU		75 (27.8)	36 (27.5)	39 (28)
Direct to operating room		16 (6.0)	5 (3.8)	11 (7.9)
Discharged		156 (36.6)	89 (40.4)	67 (32.5)
No. of patients requiring surgery	426	92 (21.6)	46 (20.9)	46 (22.3)
ISS Minor (0-8)	426	- 287 (67.4)	- 142 (64.5)	- 145 (70.4)
Moderate (9-15)		89 (20.9)	52 (23.6)	37 (18)
Severe (16-24)		40 (9.4)	20 (9.1)	20 (9.7)
Critical (>= 25)		10 (2.3)	6 (2.7)	4 (1.9)
Length of stay (d)	426	4.5 (8.3)	3.9 (6.8)	5.2 (9.6)
Mortality	426	12 (2.8)	4 (1.8)	8 (3.9)

Abbreviations: BMI, body mass index; BP, blood pressure; n, number in population. Categorical variables are expressed as count (%) and continuous variables are expressed as mean (SD).

Table 2

Analysis of missed and incidental injuries pre- and post-PS introduction

Injuries	Pre-pan-scan period (n = 220), n (%)	Pan-scan period (n = 206), n (%)	OR (95% CI)	P
No. of patients with missed injuries	7 (3.2)	1 (0.5)	6.7 (0.82-55.3)	.069
No. of missed injuries	7 (1.25)	1 (0.2)	6.2 (0.76-50.51)	.074
Missed, minor	4 (57.1)	1 (100)	0.4 (0.01-14.1)	1.000
Missed, major	3 (42.9)	0 (0)	2.3 (0.07-76.7)	1.000
No. of patients with incidental findings	137 (62.3)	158 (76.7)	0.5 (0.33-0.76)	.002?
No. of incidental findings	Total: 349	Total: 590	Difference:	b.0001?
	Mean (SD): 1.6 (1.9)	Mean (SD): 2.9 (3.1)	1.3 (0.8-1.8)
Incidental, minor	348 (99.7)	585 (99.15)	2.9 (0.3-25.6)	.421
Incidental, major	1 (0.3)	5 (0.85)	0.3 (0.04-2.9)	.421

Abbreviations: OR, odds ratio; n, number of patients in population; n (%), count (percentage).

* P b .05.

PS period. When radiology cost was separated into fixed vs variable and CT vs x-ray, the introduction of the PS protocol increased the total fixed CT cost per patient by $48.1 (95% CI, 32-64.1; Table 5). Radiation exposure was also analyzed (Table 6). The radiation dose for each CT scan performed on a patient during and after the trauma assessment was obtained. As the number of CT scans increased during the PS period, the average radiation dose per patient increased by 8.2 mSv (95% CI, 5.0-11.3).

Limitations

The main limitation of the study is that it was done at a single center; therefore, the results cannot be generalized. This was not a randomized study, which would have been a better approach to this study. In addi- tion, the PS protocol was not a single pass scan, each scan was done sep- arately. Using a single-run protocol might have reduced the radiation exposure. Another limitation was the cost data; the radiology cost was not separated into ED vs non-ED radiology cost. However, most scans were ordered in the ED before hospital admission. Lastly, in the context of trauma, radiologists may have excluded some minor incidental findings while focusing on traumatic injuries.

Discussion

There is debate over whether or not the benefits of pan-CT outweigh the risks. Generally, PSs are reported to decrease mortality, missed injuries, and treatment times at the expense of increased radiation, incidental findings, and hospital costs. No single study has attempted

to address all these factors in a Prospective analysis to determine what the effects would be on each factor with the introduction of a PS paradigm in a previously selective scan environment. A recent random- ized study, focused on severely injured patients, addressed some of these factors but did not address time to the operating room, radiology cost, missed injuries, and incidental findings [17]. In this study, we determined that a PS protocol during the initial trauma assessment minimized missed injuries, and decreased various time intervals while increasing incidental findings, radiation exposure, and scanning cost. Mortality was not affected.

Injuries were considered missed if they were not identified during the initial trauma assessment but were later found by either x-ray or CT. Before the introduction of the PS protocol, there were 7 patients with missed injuries. After the PS was introduced, only 1 patient had a missed injury. Of the 8 patients with missed injuries, 2 (25%) had a PS and 6 (75%) were selectively imaged or not imaged at all. It is important to note that the 1 patient with a missed injury, during the PS period, had a PS. However, an orbital roof fracture was only detected on a later CT image of the maxillary face. If a PS was initially done during trauma triage, many of the missed injuries would have been detected earlier. This suggests that a PS may decrease the number of missed injuries in patients with blunt trauma.

The impact of pan-CT on incidental findings has not been widely re- ported. As expected, the increase in scans during the PS period increased the number of incidental findings. However, implementation of a PS protocol did not significantly increase the number of clinically relevant incidental findings. During the PS period, 5 incidental findings required follow-up within 30 days. In our population, there was a high rate of

Table 3

Missed injuries

Type of missed injury	Mechanism of injury	Imaging on arrival	Other injuries	Treatment of missed injury	Disposition
Rib fracture (1) (12th)	Motorcyclist vs motor vehicle	CT head, maxillary face	subdural hematoma with Midline shift of 1 cm, vault of Skull fracture, tibia fracture,	None	Died
Subcapital femur fracture	Fall	CT head	clavicle fracture, facial laceration Concussion	None	Transferred
Rib fractures (3) (4th, bilateral 5th) Intertrochanteric femur	Driver in motor vehicle accident Pedestrian vs motor vehicle	CT head, C-spine, abdomen/pelvis None	Concussion, contusion of knee, rib fractures (7-10th) None	None ORIF hip	Home Home

fracture

Subtrochanteric femur fracture Fall None None ORIF hip/femur Rehabilitation

Nasal bone fracture Fall CT head, C-spine Open wound of nose closed reduction of fracture

Home

Orbital roof fracture Pedestrian vs motor vehicle CT head, C-spine,

chest, abdomen/pelvis

Facial laceration None Home

Temporal bone fracture Fall CT head, C-spine, chest, abdomen/pelvis

Subarachnoid hemorrhage, dislocation of finger PIP joint,

rib fractures, lung contusion/laceration,

pneumothoraces,

transverse processes vertebra fracture, shattered spleen and left kidney

None Home

Abbreviation: ORIF, open reduction and internal fixation. All “missed” injuries were later identified by either x-ray or CT, after evaluation by the trauma team.

Table 4

Analysis of various time intervals pre- and post-PS introduction

Time variables	Pre-pan-scan period (n = 220), mean (SD)	Pan-scan period (n = 206), mean (SD)	Difference (95% CI)	P
Length of stay (d)	3.9 (6.8)	5.2 (9.6)	1.3 (-0.33 to 2.88)	.239
Length of stay (d) (ISS N 8)	7.7 (8.9)	12.9 (14.4)	5.2 (0.99 to 9.34)	.060
Length of stay in SICU (d)	7.4 (10.9)	9.7 (12.7)	2.3 (-2.62 to 7.23)	.855
Length of stay in SICU (d) (ISS N 8)	8.2 (11.6)	11.8 (13.8)	3.6 (-2.32 to 9.46)	.411
Length of stay in ED (min)	459.1 (422.8)	390.9 (256.2)	-68.2 (-134.4 to -2.1)	.026?
Length of stay in ED (min) (ISS N 8)	411.0 (614.5)	229.0 (164.2)	-182.0 (-326.4 to -37.63)	.0008?
Time to 1st operating room visit (min)	2946 (2953)	1481 (2047)	-1465 (-2519 to -411)	.002?
- Direct to operating room (min)	100.2 (43.8)	136.5 (68.2)	36.3 (-25.65 to 98.16)	.304
Time to 1st operating room visit (min) (ISS N 8)	2946 (3112)	1621 (2353)	-1325 (-2721 to 70.74)	.012?

n, number of patients.

* P b .05.

incidental findings, which poses a concern. We predominantly serve uninsured and underserved communities that have limited access to primary preventative care, which may account for the high percentage of patients with incidental findings. The discovery of incidental findings in patients with trauma poses a burden on the health care system and increases cost due to the additional evaluation required to prevent adverse outcomes. However, the major concern is the unnecessary expenditure for inconsequential incidental findings identified on whole-body CT.

Several studies have demonstrated that pan-CT decreased the length of stay in the hospital and the length of time to diagnosis and treatment. The introduction of the PS protocol did reduce the time spent in the ED and the time to the first operating room visit. These 2 time intervals are likely indicators of the time to diagnosis and treatment, and their reduction during the PS period in the face of no other changes strongly implies a faster progress of patients through the hospital system. Our study confirms that pan-CT accelerates the time to care.

Contrary to other studies, the mortality rate did not significantly

decline after the introduction of the PS protocol. In fact, during the PS period, the mortality rate doubled, but this increase was not significant. This is likely due to the relatively small number of patients that are included in this study; however, larger randomized studies had similar results [17]. Of note, injury severity was similar before and after the introduction of the PS protocol. There was a 6.4% increase in patients with an initial GCS of 3 during the PS period, which may account for the 2-fold increase in mortality. In this study, there was no apparent correlation between CT scans and mortality. Previous studies that found this association are registry based and had 2 confounding factors in their design. First, the most critically ill patients, who have the highest mortality, cannot tolerate any CT scans and are therefore relegated to the non-PS group. Second, newer centers that deliver state-of-the-art care are more likely to have a CT scanner integrated into their ED. In theory, patients at these centers will have a better survival rate because a disproportionately larger percentage of patients will receive a PS compared with those at older less advanced hospitals, by this means skewing the populations.

A PS is considered a useful tool for patients who have a diminished level of consciousness and who are severely injured or are suspected to have multiple injuries. In our population, 11.7% of the patients had a GCS b 12. However, when patients were subgrouped based on GCS b 12, there was no change in time to care or number of missed injuries after the introduction of the PS protocol. Injury severity was similar between the 2 groups. As expected, patients with an injury severity score greater than 8 had a shorter length of stay in the ED. After the introduction of the PS protocol, the average length of stay in the ED further decreased by 3 hours for patients with the most severe injuries. Therefore, injury severity but not GCS may be a better indica- tion for a PS. Presently, injury severity is calculated retrospectively; therefore, new prospective ways of determining injury severity in the trauma bay are needed.

It is important to note that 44.1% of the patients during the pre-PS period had a PS and 8.25% of the patients during the PS period did not have a PS. With the introduction of the PS protocol, there was a shift from 55.9% to 8.25% of blunt trauma activations receiving selective CT scanning and from 44.1% to 91.75% receiving a PS. This ~48% increase was sufficient to decrease missed injuries by 3.1%, length of stay in the ED by 68.2 minutes, and time to the first operating room visit by 24.4 hours. This suggests that there is a significant benefit to using pan-CT in patients with blunt trauma.

Because the body mass index of the groups pre- and post-PS intro- duction was similar, the specific radiation dose for each patient was de- termined. In general, our population was overweight; therefore, radiation exposure was high. However, the average radiation exposure increased by 8.2 mSv during the PS period. This was due to the increase in the number of scans ordered during the trauma assessment. The total number of scans ordered after the trauma assessment did not change after the introduction the PS protocol. Many of the scans ordered later in the hospital stay were repeat head CT scans for known Traumatic brain injuries and CT scans of the chest and abdomen/pelvis. In our pop- ulation, the average effective radiation dose for a PS was 23.8 mSv which is similar to reported averages of 24 mSv [7,22]. According to Verdun et al [23], an effective dose of 10 to 100 mSv is considered low risk

Table 5

cost analysis pre- and post-PS introduction

Cost variables	Pre-pan-scan period (n = 220), mean (SD)	Pan-scan period (n = 206), mean (SD)	Difference (95% CI)	P
Hospital stay cost ($)	13 573 (25507)	18 544 (36800)	4971 (-1100 to 11 042)		.010?
Radiology cost ($)	1362 (1297)	1312 (1017)	-50 (-271.1 to 171.4)		.629
Fixed radiology cost ($)	618 (565)	665 (506)	47 (-55.4 to 148.5)		.042?
Variable radiology cost ($)	744 (735)	647 (511)	-96 (-216.3 to 23.53)		.371
CT scan cost ($)	361 (205)	415 (132)	54 (21.3 to 86.5)	b.0001?
Fixed CT scan cost ($)	174 (97)	222 (70)	48.1 (32 to 64.1)	b.0001?
Variable CT scan cost ($)	187 (109)	194 (63)	6.8 (-10 to 23.7)	.079
Diagnostic x-ray cost ($)	1001 (1195)	897 (957)	-104 (-309.3 to 101.9)	.213
Fixed diagnostic x-ray cost ($)	445 (517)	443 (474)	-1.5 (-95.9 to 92.9)	.581
Variable diagnostic x-ray cost ($)	557 (679)	453 (483)	-103.2 (-214.9 to 8.5)	.066

n, number in population.

* P b .05.

Table 6

Analysis of radiation exposure pre- and post-PS introduction

	Pre-pan-scan period (n = 220)	Pan-scan period (n = 206)	Difference (95% CI)	P
No. of patients receiving selective scans	123 (55.9%)	17 (8.25%)	47.6% (38.7 to 56.6)	b.0001?
No. of patients receiving pan-scan	97 (44.1%)	189 (91.75%)	47.6% (38.7 to 56.6)	b.0001?
CT scans ordered during trauma assessment	Total: 737	Total: 883	0.94 (0.7 to 1.1)	b.0001?
Radiation dose (mSv), mean (SD)	Mean: 3.3 18.4 (15.1)	Mean: 4.3 26.8 (12.0)	8.4 (5.8 to 10.9)	b.0001?
CT scans ordered after trauma assessment	Total: 47	Total: 46	0.01 (-0.1 to 0.12)	.581
	Mean: 0.2	Mean: 0.2
Radiation dose (mSv), mean (SD)	1.5 (7.3)	1.3 (6.9)	-0.2 (-1.6 to 1.1)	.566
Total scans	Total: 784	Total: 929	0.9 (0.7 to 1.2)	b.0001?
	Mean: 3.6	Mean: 4.5
Radiation dose (mSv), mean (SD)	19.9 (18.9)	28.1 (14.3)	8.2 (5.0 to 11.3)	b.0001?

n, number of patients in population.

* P b .05.

(10^-3) for cancer, whereas greater than 100 mSv is considered moder- ate risk (N10^-2). In our study, 99.5% of patients were low risk for cancer and 0.5% had a moderate risk of cancer, an insubstantial number when extrapolated to the entire population of patients with blunt trauma nationwide. However, these results do not take into account age, sex, and natural risk, which all contribute to the risk of death from cancer. In addition, the overall radiation exposure could have been significantly reduced by the utilization of a defined single-run PS protocol as opposed to simply performing each individual component of the PS separately and combining them. Eliminating the overlap between scans and the reduced radiation needed for such a CT can dramatically reduce exposure.

Not much has been done to determine if selective scanning is more cost effective than whole body CT. In this study, both total cost and radi- ology cost were analyzed. The average cost to treat a blunt trauma acti- vation patient increased by $4971 during the PS period. However, many factors, such as comorbidities, may contribute to this increase. The de- mographics and medical status of patients in both the pre-PS and PS pe- riods were similar; however, the small size of the groups indicates that a few outliers could have greatly affected the data. In the PS group, there was an increase in the number of patients with a GCS of 3, the number of patients requiring intubation, the number of patients who went directly to the OR from the ED, and the length of stay in the hospital. Whether these factors facilitated an increase in the cost is unknown, but each of these factors can negatively impact cost. On the other hand, the intro- duction of the PS protocol did not have a significant effect on the total radiology cost, which is where an effect of PS should most readily be ev- ident. As expected, the fixed CT cost increased during the PS period. When radiology cost was separated into CT and diagnostic x-ray cost, the cost of diagnostic x-rays decreased during the PS period. This sug- gests that there may have been a decrease in the number of x-rays per- formed during the PS period, which canceled out the increase in the fixed CT cost.

In conclusion, despite the outcomes of the study, it is difficult to jus- tify the use of a PS on every patient with blunt trauma. For intoxicated and intubated patients, a PS may be necessary because performing a physical examination may be challenging. In our population, ~33% of the patients were positive for alcohol use, ~ 9% were positive for illegal drug use, and ~12% were intubated in the trauma bay. In trauma care, overtriage and undertriage of patients can be a problem. The introduc- tion of a PS protocol raised the possibility of overtriage in some patients. In our study, 67.4% of patients had an ISS b 8, 65% of which had a PS. Not to mention, only 30% of the patients who had a PS had an injury in 2 or more body regions and only 2.8% had an injury in all the 4 components of a PS. In addition, there were only 5 major incidental findings identi- fied during the PS period, with none requiring immediate intervention. Moreover, ~80% of the scans done during the PS period were negative, which makes it difficult to justify the necessity of a PS for all blunt trauma activations. This is especially true when cost and the potential long-term risk of radiation exposure are taken into consideration.

Author Contribution

Study concept and design: MKJ, SDS, SWL, GKD Data collection: MKJ, SWL, SDS, MPF Data analysis and interpretation: MKJ, SDS, SWL

Manuscript preparation and critical revision: MKJ, SDS, SWL

Acknowledgments

The authors thank Gideon Yoeli, MD, from the Department of Radiology at Jamaica Hospital Medical Center for his advice on radiation dose and incidental findings.

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