Comparing patients with renal trauma who were transferred versus those who were not transferred from outside hospitals gives us an important understanding of the potential differences that can be seen regarding imaging protocols and overall clinical outcomes. Our study aims to bridge the gap in literature regarding imaging techniques and follow-up rates between transferred patients and non-transferred patients with renal trauma, as well as add to the existing literature regarding complication rates between these groups. Within the transferred cohort, distance from our level 1 trauma center was associated with complications, although this was not statistically significant. Greater transfer distances may indicate the patient was transferred in a rural setting at a community hospital that may have limited trauma capabilities. Alternatively, patients transferred from shorter distances were often initially seen at a well-resourced hospital in the greater metro-area. With this study we provide data on the roles transfer status and distance play in initial diagnosis, management, and outcomes. Existing literature shows transfer status and trauma center level are not correlated with complication rates or risk for operative management [5–7], but it is crucial to assess all variables impacted by transfer status that may alter management and long-term outcomes.
It is important to note the unique geography of our level 1 pediatric hospital. The mountain range neighboring our institution contains many ski and recreation areas > 50 miles from our hospital that send trauma patients to our hospital. The patients we treat for renal trauma from these locations are often due to high speed mechanisms involved with many mountain sports-related injuries. Our institution is only one of two pediatric hospitals in the metropolitan area, which may increase the volume of patients transferred from these recreational areas. In our study, blunt trauma was a more common mechanism of injury compared to penetrating trauma, as 34/35 of the renal injuries were due to blunt trauma. This finding is in line with existing literature that shows blunt trauma as a more common cause of renal trauma compared to penetrating trauma [6]. Interestingly, the most common mechanism of injury in both transferred and non-transferred patients was sports related at 46.2% and 44.4%, respectively. While our unique geographic location may have an impact on various data points, it appears that the recreational activities in the nearby mountain recreational areas may not increase our sports related injuries compared to non-transferred patients.
Immediate complications and transfer status in renal injury have been studied more extensively compared to imaging techniques or follow-up rates. In one study of 1,177 pediatric patients with low-grade (grade I-III) isolated solid organ injury, transfer to a higher level trauma center did not lower risk of surgery, and non-transferred patients had a 0.63 times lower risk of staying in the hospital for an additional day compared to patients who were transferred to a higher level trauma center. This study showed that reduction of unnecessary transfers could be an opportunity for cost savings and shorter hospital stays in pediatric trauma [8]. It is important to note these findings are referring to low-grade solid organ injuries and do not represent all solid organ trauma. Another study of 3,246 pediatric renal trauma patients of any AAST grade showed no significant difference in complication rates, rate of surgical intervention, or nephrectomy between patients seen at level 1 vs. non-level 1 trauma centers. Additionally, higher renal injury grade and injury severity score were highly correlated with operative management, whereas trauma level designation was not found to be predictive for more aggressive management [9]. In contrast with this existing literature, the two cohorts in our study appear to show non-significant differences in immediate complications. While this is not statistically significant, there may be a clinically significant difference considering that 23% of transferred patients experienced at least 1 immediate complication compared to 0% of non-transferred patients.. Likely, this is an indication that the patients being transferred in our cohort are high-grade injuries and thus, more prone to complications/poor outcomes, which would confirm findings shown in the literature. Increased time from initial injury to arrival at the level 1 pediatric trauma center may also be a factor in increasing complications, but a larger sample size is needed to properly analyze this relationship between time to arrival and complications. Similarly, rates of immediate complications were non-significantly increased in the group transferred from > = 50 miles away. This could be due to many different aspects of being transferred from longer distances, most importantly, the significance of injuries or non-related injuries present that required higher level of care. Other aspects may include but are not limited to lack of pediatric urology team or general pediatric hospital, transfer modality, mechanism of injury, and length of time between injury and presentation at outside hospital. Patients who live in rural areas may live farther from the nearest hospital when compared to patients who live in metro areas, so time from injury to initial presentation may play a role, as well as mechanism of injury based on geographic location as previously discussed, and types of immediate complications as previously discussed. Time of arrival at outside hospitals was difficult to ascertain through chart review but should be looked at in further studies. Interestingly, time between injury and presentation at the level 1 pediatric trauma hospital did not appear to be different between these two groups. Larger studies are needed to better understand the association between transfer distance and complication risk, asthis information will be crucial in developing protocols to improve immediate and long-term outcomes of transferred patients.
Radiation exposure is an important variable to consider during the initial diagnosis and management of pediatric renal trauma due to the adverse long term effects of radiation in pediatric populations [10]. The widely used ALARA (as low as reasonably achievable) principle is heavily emphasized in pediatrics to decrease unnecessary radiation exposure in all populations [11]. Regarding the reduction of radiation exposure in pediatric patients with renal trauma, evidence shows utilizing ultrasound for monitoring of renal trauma after obtaining diagnostic CT scan is an effective way to decrease radiation exposure [12, 13]. In patients being treated for renal trauma at more than one institution by multiple providers, the ALARA principle may be compromised due to lower pediatric imaging protocol adherence or lack of outside hospital image transfer, leading to increased radiation exposure. With this study, we aimed to identify differences in radiation exposure between transferred and non-transferred patients. While looking at the 26 patients who were transferred, 15% received at least one repeated imaging exam compared to 0% in non-transferred patients. This finding was not statistically significant due to sample size, but may be clinically significant. The transferred cohort did receive a slightly higher percentage of CT scans during initial diagnosis compared to the non-transferred group, who received a small percentage higher of FAST exams, which afford less radiation exposure. In contrast with findings regarding repeat images, transferred patients received a lower percentage of total images compared to non-transferred patients. These findings are reassuring against pediatric overexposure to radiation at this institution and adherence to ALARA principles in general, but may indicate that transferred patients are receiving a higher number of repeated images.
Per our hospital protocol, outside are images pushed to the patient’s EHR which allows for the images to be read by the in-house radiologists and/or trauma team, thereby avoiding unnecessary re-imaging once patients are transferred. This institutional protocol to obtain outside images of transferred patients is a key systemic implementation of the ALARA principle and highlights the importance of cross-institutional EHR access and/or timely record transfer. This may help to prevent unnecessary radiation exposure and should be considered in level 1 trauma centers that have identified unnecessary levels of radiation exposure. Larger studies including institutions with and without these imaging protocols are needed to more definitively establish the correlation of this hospital protocol with radiation exposure and associated sequelae.
Renal trauma in the pediatric population is unique compared to adults. Increased risk for injury and complications due to the relative size and lack of rib protection of the pediatric kidneys, increased likelihood of undiagnosed congenital urogenital tract anomalies leading to complications, and the task of minimizing pediatric radiation exposure can present challenges in management [12, 14–17]. Although challenges differ from the those faced in the adult population, the 2019 Eastern Association for the Surgery of Trauma (EAST) pediatric blunt renal trauma practice management guidelines recommend non-operative management with close monitoring for post-traumatic renal hypertension as the gold standard management for both adults and pediatrics[17, 18]. High grade renal trauma requires close follow-up with urology for long-term sequelae and management [19], yet there is lacking data describing the relationship between transfer status or distance and follow-up frequency. This study showed no difference in follow-up visits between transferred and non-transferred patients. Interestingly, there was no difference in follow-up visits or long-term complications when separating the transferred group into patients being transferred from > 50 miles away or < = 50 miles away. Number of follow-ups were only counted if the follow-up occurred with the urology department at our trauma center. This data may indicate no correlation between transfer status and follow-up or distance and follow-up, and may further indicate adherence to the EAST blunt renal trauma follow-up guidelines within our institution. The similar long-term complication rates between the > 50 mile distance group and the < = 50 mile distance supports the existing evidence that follow-up in renal trauma is crucial to the prevention and monitoring of complications. It is important to note, distance travelled was calculated using the distance of the transferring hospital from our level 1 trauma center, and not the patient’s home address. Taking into consideration our geographic location discussed above, a large number of outdoor activities in the neighboring mountains produce renal trauma in patients who do not live in the area where the injury occurred. These patients may present to an outside hospital that is farther from our institution than their home address a potential confounder not accounted for in the data. Future, larger studies should include distance of transferring hospital as well as the home addresses of patients to more accurately assess the effect of distance on follow-up. Even with these limitations in mind, these findings show that transferred patients are receiving similar follow-up to their non-transferred counterparts at our institution, and outside hospital distance to our level 1 trauma center does not affect follow-up or long-term complications.
There are several limitations to this study. Our study is not powered to show a significant difference given the small number of patients in this cohort. The results of this single institution study may not be generalizable on a national scale due to institutional practices, such as use of the EHR to facilitate data and image sharing. Follow up may be skewed due to the fact that some patients had follow-up outside of this level 1 pediatric care center’s network, leading to potentially unreliable data. Finally the time frame of this study may lead to underrepresentation of complications in more recently seen patients. Despite these limitations, this cohort of pediatric renal trauma patients provides valuable information regarding less studied topics such as radiation exposure, follow-up, and complications in transferred renal trauma patients. More studies are needed to better understand factors associated with renal trauma outcomes, including transfer from adult hospital to pediatric hospital, mechanism of injury, and geographic location.