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http:// ijp.mums.ac.ir Original Article (Pages: 8047-8059)

The Utility of Ultrasound and Laboratory Data for Predicting Intra-abdominal Injury among Children with Blunt Abdominal Trauma Ayoub Ashrafi1, *Farhad Heydari2, Mohsen Kolahdouzan31 1

Emergency Medicine Specialist, Alzahra Hospital, Emergency Medicine Specialist, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran. 2 Emergency Medicine Research Center, Alzahra Hospital, Department of Emergency Medicine, Isfahan University of Medical Sciences, Isfahan, Iran. 3 Associate Professor, Alzahra Hospital, General Surgery Specialist, Thoracic Surgery Subspecialist, Associate Professor of Isfahan University of Medical Sciences, Isfahan, Iran.

Abstract Background: Children with blunt abdominal trauma (BAT) can be risk stratified for intra-abdominal injury (IAI) through a combination of readily accessible clinical variables. The aim of this study was to identify ultrasound and laboratory studies that accurately identify IAI while limiting unnecessary CT-scan among children without injury. Materials and Methods We conducted a prospective, observational study of 2-12 years old children with BAT who referred to the emergency department (ED) at Al-zahra and Kashani hospitals in Isfahan city, Iran, from January 2013 to May 2014. Children were undergone abdominal ultrasound and abdominal CT scan was done at the discretion of the treating physicians and according to the CT protocols. The tests obtained to assess for an IAI were including hematocrit (HCT), amylase, aspartate aminotransferase (AST) or alanine aminotransferase (ALT) and urinalysis (U/A). The outcome were any IAI and intra-abdominal injury undergoing acute intervention (IAI-I). Results: We enrolled 101 children with a median age of 6.75 ± 3.2 years. There were 18 (17.8%) patients with IAI, and 5(5%) patients with IAI-I. The sensitivity, specificity and positive predictive value and negative predictive value of ultrasound compared to CT- scan were 72.2%, 85.5%, 52%, and 93.3%, respectively. It is notable that all 18 patients with IAI (Se=100%) had at least one positive test. The combination of ultrasound, ALT/AST, HCT, urinalysis and amylase tests (with at least one positive test) has negative predictive values of 100%. Conclusion: It can be argued that ultrasound combined with selected laboratory studies can be used to predict the risk of IAI accurately among children who sustain BAT. According to the results of this study, we can say that ultrasound and laboratory studies should be obtained as a screening tool in these cases. Key Words: Blunt abdominal trauma, Emergency department, Pediatric, Ultrasound. *Please cite this article as: Ashrafi A, Heydari F, Kolahdouzan M. The Utility of Ultrasound and Laboratory Data for Predicting Intra-abdominal Injury among Children with Blunt Abdominal Trauma. Int J Pediatr 2018; 6(8): 047-59. DOI: 10.22038/ijp.2018.29824.2626

*Corresponding Author: Farhad Heydari, Emergency Medicine Research Center, Alzahra Hospital, Department of Emergency Medicine, Isfahan University of Medical Sciences, Isfahan, Iran. Email: [email protected] Received date: Feb.05, 2018; Accepted date: Mar. 22, 2018

Int J Pediatr, Vol.6, N.8, Serial No.56, Aug. 2018

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Ultrasound and Laboratory Studies as Screening Tools in Pediatric Abdominal Trauma

1- INTRODUCTION The life of critically ill or injured children depends on the speed and accuracy of emergency cares. These cares start with rapid diagnosis of serious diseases and continue in all conditions before and after hospitalization. Despite profound advances in reduction of adults’ mortality in emergencies, due to difficult diagnosis of life-threatening disorders in kids, this index has not significantly decreased in kids (1, 2). Intra-abdominal injury (IAI) is a leading cause of morbidity in children (3), and early identification is imperative to minimize morbidity and mortality from delayed or missed diagnosis. The most important mortality cause in 2-12 years old kids is accidents which half of it consists of accidents with motor vehicles. The next main cause of death in kids includes falling (25 - 30%) (3-6). More than half of death incident due to trauma happens in the place of accident. While if patient reaches care center and has a constant condition for one hour after injury, he/ she will have a good fate (3, 4). Blunt abdominal trauma (BAT) is very common in children. The most susceptible parts that suffer are spleen, liver, genitourinary tract, stomach, small intestine, colon, pancreas, pelvis and large vessels, respectively (7, 8). Optimal treatment of affected kids with stable condition requires frequent physical examination and performing CT-scan to prove the presence and extent of injury. In case of unstable vital signs in addition to severe fluid resuscitation, even if the extravascular volume has not decreased or the abdomen has not enlarged the patient might require surgery. If there are signs of peritoneal irritation or discoloration of abdominal wall along with signs of intravascular volume depletion, laparotomy is necessary. In the studies, CT-Scan is proposed as the standard diagnostic instrument; however, CT-scan equipments are not available in all medical


centers and areas. It has important drawbacks, primarily that it exposes patients to relatively large radiation dosages, placing them at increased risk of radiation-induced malignancy (9).Thus, it is required to try to achieve some instrument which can specify the status of patient reliably with high accuracy. In this regard, the studies which have been done indicated the great role of ultrasound in rapid and immediate diagnosis of some injuries (10-13). Several studies suggest that children with BAT can be risk stratified for IAI through a combination of readily accessible clinical variables (1417). Thus, concerning the abovementioned findings and the fact that ultrasound is less aggressive than CT-scan and more available, in case of efficiency, this instrument can replace CT-scan. The present study aimed to identify ultrasound and laboratory studies that accurately identify IAI while limiting unnecessary CT-scan among children without injury. Variables (ultrasound and laboratory studies) available at the time of initial ED evaluation were considered as potential predictors. 2- MATERIALS AND METHODS 2-1. Study Design We conducted a prospective, observational study of children with BAT that was referred to the ED. The study was approved by the by the Ethics Committee of Isfahan University of Medical Sciences (IR.mui.RES.1392.3.292). This study was conducted at Al-zahra and Kashani hospitals in Isfahan city, Iran, from January 2014 to May 2015. 2-2. Selection of Participants Children with BAT evaluated in the ED at Al-zahra and Kashani hospitals in Isfahan, Iran from January 2013 to May 2014 were eligible. Inclusion criteria were children 212 years of age presenting with BAT due to predefined high-risk mechanism of

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injury. We chose to include children with high-risk mechanisms of injury because of several authors have suggested would be most likely to benefit from CT-scan (18-

20). High-risk mechanisms of injury were chosen based on review of existing literature (18-22) (Table.1).

Table-1: High-risk mechanisms High-speed motor vehicle collision (≥40mph or 64 kph ) Ejection from vehicle Death of another passenger in same vehicle compartment Falls from >10 feet (3 m) or more than 2 to 3 times patient height or >5 stairs Roll-over of vehicle Vehicle-pedestrian/bicycle collision with >5 mph (8 kph) impact Motorcycle crash >20 mph (32 kph) or with separation of rider from bike (Reference: American College of Surgeons, Committee on Trauma: Resources for the optimal the injured patient, Chicago, 2012). Mph: miles per hour; kph: kilometers per hour.

Patients were excluded if they met any of the following criteria: abnormal pediatric age-adjusted shock index (heart rate/systolic blood pressure), Glasgow coma scale 12 h after trauma or transferred from another hospital. 2-3. Study Protocol The sampling method was census and all children having inclusion criteria referred to these centers in the mentioned time interval were included in this study. The minimum required sample was estimated through estimation formula of sample volume for prevalence studies, reliability of 95% confidence interval, and ultrasound sensitivity of 0.8 and error acceptance rate of 0.1 as 61 individuals and subjects. We recorded demographic variables (age and gender), mechanism of injury (motor vehicle collision, pedestrian struck, cyclist struck, fall down stairs, fall from height, assault), physical examination findings, laboratory values of hematocrit (HCT), amylase, aspartate aminotransferase (AST) or alanine aminotransferase (ALT), and urinalysis (U/A), ultrasound and


care

of

abdominal CT findings. Observed loss of consciousness at the scene and in the hospital, the time from injury until initial evaluation and whether this evaluation was first performed at another hospital were evaluated. Recorded data collected included aspects of the physical examination included the initial vital signs (blood pressure, pulse, respiratory rate, and temperature), abdominal examination (the presence or absence of distention, abrasions, ecchymosis, seatbelt or handlebar contusion or tenderness), and Glasgow Coma Score (14). The method of study was such that 2-12 years old kids suffering from BAT were undergone abdominal ultrasound after taking their history and physical examination. Abdominal exam was considered abnormal if physician documentation described tenderness to palpation, peritonitis, presence of distention, abrasions or seatbelt or handlebar contusion. To prevent any bias, all ultrasounds were performed by an expert radiologist and the results were recorded in special checklist. On the other hand, the abdominal and pelvic CT-scan for these kids was done by intravenous

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contrast and was performed at the discretion of the treating physicians and according to the CT protocols at each institution. The radiologist who performed the ultrasound of patient was unaware of CT-scan results. We conducted follow-up at least 14 days after the first ED visit to identify any IAI that subsequently received. Patients were defined as having no IAI if no injury was detected during initial evaluation, during hospitalization, or at outpatient follow-up evaluation. The final results obtained from ultrasound and CT-scan was recorded. The results of tests obtained to assess for an IAI were noted including: HCT, amylase, AST or ALT, and urinalysis. Laboratory abnormalities were as follows: ALT and AST > 200 U/L, HCT < 30%, amylase >100 U/L and hematuria > 5 (Red Blood Cells per High Power Field) in U/A. According to the study patients were assessed for 6 clinical variables (ultrasound, abdominal exam, AST/ALT, HCT, amylase, hematuria) potentially associated with IAI. The presence of any one of these six variables was considered predictive of IAI. 2-4. Outcome Measures The primary outcome was any IAI. Intraabdominal injury was defined as any abdominal CT-Scan or surgically apparent injury to the following structures: spleen, liver, urinary tract (from the kidney to the urinary bladder), gastrointestinal tract (including the bowel or associated mesentery from the stomach to the sigmoid colon), pancreas, gallbladder, adrenal gland, intra-abdominal vascular structure, or traumatic fascial defect (traumatic abdominal wall hernia). The secondary outcome was intra-abdominal injury undergoing acute intervention (IAII). Acute intervention was defined by an IAI associated with death caused by the


intra-abdominal injury, therapeutic laparotomy and blood transfusion for anemia as a result of hemorrhage from the IAI. 2-5. Data Analysis Sensitivity, specificity, positive and negative predictive values and accuracy of the six variables were calculated. Logistic regression models were then used to determine whether abnormal value variables were related to the presence of IAI. The data were analyzed by SPSS version 20.0 and Med Calc. The result of CT-scan and ultrasound in patients were compared with liver enzymes, amylase and urinalysis. Parametric data were expressed as means (standard deviation) and analyzed using the unpaired, two-tailed Student’s t test, assuming the variance to be equal. The Mann– Whitney test was used to compare ordinal variables. Differences between groups were analyzed using Fisher’s exact test. P-value less than 0.05 were statistically significant. 3- RESULTS Of the 168 eligible patients, we enrolled 101 (60.1%) (Figure.1); the average age of these patients were 6.75±3.2 years in range of 2-12 years old. In terms of gender distribution, 69 individuals (68.3%) were male and 31 (30.7%) were female. The average age of studied girls and boys was 6.47±3.12, and 7.16±2.84 years, respectively; and according to t-test, no significant difference was observed between two genders (p= 0.37). The mechanisms of injury for the 101 patients were as follows: motor vehicle collision in 55 (54.5%), pedestrian struck by auto in 15 (14.9%), cycle struck by auto in 6 (5.9%), fall from height in 9 (8.9%), fall from stairs in 7 (6.9%), assault in 2 (2%) and other in 6 (5.9%) (Table.2).

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Fig.1: Flow Diagram of Pediatric Patients with Blunt Abdominal Trauma.

Table-2: Description of All Study Patients, Then Stratiﬁed by Patients with and Without Intra Abnormal Injury. Variables Age(Mean + SD),year

Total, (n=101) 6.75 ± 3.2

IAI, (n=18) 6.95 ± 3.5

Without IAI, (n=83) 6.69 ± 2.9

69(68.3)

13(72.2)

56(67.5)

55(54.5) 15(14.9) 6(5.9) 7(6.9) 9(8.9) 2(2) 6(5.9)

10(55.6) 3(16.7) 1(5.6) 1(5.6) 2(11.1) 0(0) 1(5.6)

45(54.2) 12(14.5) 5(6) 6(7.2) 7(8.4) 2(2.4) 5(6)

Gender (% male) Mechanism of injury (%) Motor vehicle collision Pedestrian struck Cyclist struck Fall down stairs Fall from height Assault Other

All studied patients were evaluated by ultrasound, urinalysis and ALT/AST. Among 101 enrolled patients 92 individuals had amylase test. Overall, 72/101 (71.3%) patients underwent abdominal CT-scan. All patients who did not undergo a CT- scan were discharged without a problem and did not have a problem in the follow up to two weeks


later. According to results, 25 (24.8%) individuals had abnormal ultrasound, 28 (27.8%) individuals had abnormal urinalysis, 31 (30.7%) individuals had abnormal amylase level, 15 (14.9%) patients had abnormal ALT/AST, and 18 (17.9%) patients had abnormal physical exam (Figure.2).

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100 90 85.1

80

87.1 82.1

75.2

70

72.2

60 50

60.3 53.5

40 30 28.7

20 10

17.8

30.7

27.8

24.8 14.9

17.9 12.9

0

9

0 CTSCAN

ULTRASOUND

ALT/AST Abnormal

HCT

U/A

Normal

AMYLASE

PH/EXAM

Unkhown

Fig.2: The frequency percentage clinical test results in studied patients.

In total, 18 patients (17.8%) were diagnosed with IAI, including 4 with injuries to more than 1 organ. The type of injury in these patients included bladder injury and severe bleeding one (5.5%), renal injury five (27.8%), liver injury eight (44.4%), splenic injury five (27.8%) gastrointestinal tract 1 (5.5%), pancreas two (11.1%). Two cases of splenic injury were transferred to operation room and three cases were observed. Just the patient with bladder rupture and two case of liver injury also were transferred to operating room. Thus 5 (5%) patients were diagnosed with IAI-I. The patient with bladder injury died later. A comparison of the ultrasound, physical examination, and results of four laboratory studies for children with and those without IAI is shown in Table.3. The children with IAI had a lower hematocrit (p=0.02), a higher concentration of ALT and AST


(p