Amylase and lipase measurements in paediatric patients with traumatic pancreatic injuries

Injury, Int. J. Care Injured 40 (2009) 66–71

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Amylase and lipase measurements in paediatric patients with traumatic pancreatic injuries Wendy C. Matsuno a,*, Craig J. Huang b, Nilda M. Garcia c, Lonnie C. Roy d, Jacqueline Davis e a

Department of Paediatrics, University of Hawaii John A. Burns School of Medicine, Honolulu, HI 96826, United States Department of Paediatrics, University of Texas Southwestern Medical Center at Dallas, Dallas, TX 75390, United States c Department of Surgery, University of Texas Southwestern Medical Center at Dallas, Dallas, TX 75390, United States d Department of Planning, Children’s Medical Center of Dallas, Dallas, TX 75235, United States e Department of Clinical Research, Children’s Medical Center of Dallas, Dallas, TX 75235, United States b

A R T I C L E I N F O

A B S T R A C T

Article history: Accepted 2 October 2008

Introduction: Pancreatic injuries occur in up to 10% of paediatric patients who suffer blunt trauma. Initial amylase and lipase measurements have not been helpful as a screening tool to detect pancreatic injuries. However, one primarily adult study suggests that a delayed measurement may be useful. Materials and methods: A retrospective chart review was conducted of patients admitted to a Level I paediatric trauma centre from April 1996 to November 2006 with traumatic pancreatic injuries. Results: The trauma database identified 51 patients with traumatic pancreatic injuries. Inclusion and exclusion criteria were met by 26 patients. Patients with initial amylase and lipase levels measured greater than 2 h post-injury were more consistently elevated compared to those patients who had levels measured at 2 h or less post-injury. There was a significant association between time of measurement and an increased amylase level (p = 0.012). No significant association was found for lipase measurements (p = 0.178). Discussion and conclusions: In children with blunt pancreatic injury, elevated serum amylase levels were seen in a significantly higher percentage of patients with initial measurements at greater than 2 h postinjury compared to those measured at 2 h or less. Lipase measurements demonstrated a similar trend. Delayed amylase and lipase measurements may be helpful to detect pancreatic injuries, but further study is needed. ß 2008 Elsevier Ltd. All rights reserved.

Keywords: Amylase Lipase Pancreatitis Paediatric

Introduction Pancreatic injury occurs in up to 10% of all paediatric blunt trauma patients.3 The pancreas is the fourth most common solid organ injured in the abdomen, after the spleen, liver and kidneys.16 Delayed management of pancreatic injuries can lead to increased morbidity, so prompt diagnosis is important.24 Laboratory data and imaging studies are often performed to help guide further

* Corresponding author at: Kapiolani Medical Center for Women and Children, 1319 Punahou Street, 7th Floor, Honolulu, HI 96826, United States. Tel.: +1 808 983 8387. E-mail addresses: [email protected] (W.C. Matsuno), [email protected] (C.J. Huang), [email protected] (N.M. Garcia), [email protected] (L.C. Roy), [email protected] (J. Davis). 0020–1383/$ – see front matter ß 2008 Elsevier Ltd. All rights reserved. doi:10.1016/j.injury.2008.10.003

management in patients with suspected traumatic intra-abdominal injury. Serum amylase and lipase levels are often obtained to help detect pancreatic injury, as computed tomography (CT) scans alone may fail to diagnose pancreatic trauma.2,4,14,15 Previous studies have shown that initial amylase and lipase measurements are not a useful screening tool to detect pancreatic injury.1,5,7,9,10,13,17,21 A primarily adult study by Takashima et al., however, showed a delayed amylase measurement, greater than 3 h post-injury, provides useful data in capturing those patients at initial presentation who may have a normal measurement.23 A similar trend in paediatric patients may be helpful to promptly diagnose pancreatic injuries in trauma patients. This study aims to review cases of traumatic pancreatic injury and determine if the timing of amylase and lipase measurements is helpful to detect traumatic pancreatic injury in the paediatric blunt trauma patient. We hypothesise that delayed amylase and lipase

W.C. Matsuno et al. / Injury, Int. J. Care Injured 40 (2009) 66–71

measurements will be elevated more consistently than those measurements taken immediately upon arrival. Materials and methods A retrospective chart review of paediatric trauma patients admitted to Children’s Medical Center of Dallas from April 1996 to November 2006 with traumatic pancreatic injuries was conducted. The Institutional Review Board (IRB) approved this study. The IRB waived the requirement for informed consent. The primary outcome measure was the number of elevated amylase and lipase measurements that were taken in the immediate period versus those taken later. The Children’s Medical Center at Dallas is a freestanding children’s hospital located in an urban area that holds the designation of being a Paediatric Level I trauma centre. The emergency department has approximately 90,000 patient visits annually. Patients who sustained traumatic pancreatic injury from April 1996 to November 2006 were identified from our Trauma Registry. Patients are included in our institution’s trauma registry if they met our trauma service activation criteria or were admitted to the trauma service. The trauma service activation criteria is a twotiered system primarily based on abnormalities in vital signs or obvious critical injuries (Trauma Stats) and mechanistic factors (Trauma Alerts). The trauma service activation criteria are available upon request. Patients were included if traumatic injury to the pancreas was diagnosed intraoperatively, by CT scan or by endoscopic retrograde cholangiopancreatography (ERCP). Patients were excluded if the patient suffered from penetrating abdominal trauma, the patient did not have an amylase or lipase measurement, or if the time of injury could not be determined from the medical record. Patient charts were reviewed and the data collected included patient age, gender, mechanism of trauma, time of trauma, history and physical exam findings, associated injuries, laboratory values, diagnostic imaging, management course, and outcome. Pancreatic injuries were classified using the American Association for the Surgery of Trauma pancreas injury scale.20 Since establishing a timeline was a critical aspect in this study, the time of the laboratory value was defined as the time of blood sample collection and the time of injury was determined from the emergency department trauma documentation. The preferential order used in the event of any discrepancy in the timing of injury was the time recorded by the first health care provider upon interviewing the family/caregiver, followed by the time of injury recorded in the emergency medical services report, and lastly the time recorded by the trauma nurse documentation. Standard laboratory ranges at our institution defined normal amylase and lipase values as being 30–110 international units/L (U/L) for amylase and 114–300 U/L for lipase. A descriptive analysis of the data is presented using frequencies, means, medians and proportions. Secondary subgroup significance testing was conducted with Chi Square and Fisher’s Exact tests with a significance level of p < 0.05. Statistical analyses were performed with SPSS v.15.000.1.

determined were victims of non-accidental trauma. A total of 26 patients remained for analysis. The mean age of patients in the study was 75.5 months (S.D. 40.5 months). There were 7 (26.9%) females and 19 (73.1%) males. There were 12 (46.2%) patients who were trauma consults, 4 (15.4%) patients met Trauma Alert criteria, and 10 (38.5%) patients met Trauma Stat criteria. The mechanism of injury for these patients is shown in Fig. 1. ‘‘Other’’ mechanisms of injury included: falls from a height, patients stumbling onto objects or objects falling onto patients. Associated injuries included 21 (80.8%) patients with intraabdominal injuries and 7 (26.9%) patients with intra-cranial injuries (Table 1). Operative intervention was performed for 17 (65.4%) patients, with a mortality rate of 7.7% (2 patients). The organ injury scale from the American Association for the Surgery of Trauma was used to further classify patients.20 There were 15 (57.7%) patients with grade I injury, 10 (38.5%) patients with grade II injury, and 1 (3.8%) patient with a grade V injury. Initial amylase and lipase measurements were compared for these 26 patients. Two patients had only post-operative amylase and lipase measurements. Their levels were not included in any further comparisons, since operative intervention would likely affect these levels. One patient did not have an associated lipase measurement with the initial amylase measurement, leaving 23 patients with amylase measurements for analysis. There were 3 patients without a concurrent lipase measurement obtained with the initial amylase measurement, leaving 21 patients with lipase measurements for analysis (Tables 2–3). Patients who had amylase and lipase levels measured at greater than 2 h post-injury were more consistently elevated compared to those whose levels were measured at less than or equal to 2 h postinjury. For amylase levels, there was a significant association between time of measurement and an increased amylase level (p = 0.012). Of those patients who had amylase measurements at greater than 2 h, 83% had elevated levels, while only 27% of those measured at less than or equal to 2 h had elevated levels. There were 89% of patients with lipase levels measured at greater than 2 h post-injury that were elevated, compared to only 58% of those measured 2 h or before. No statistical significance between time of measurement and an elevated lipase level (p = 0.178) was found. No statistically significant difference was found when comparing grade of pancreatic injury with the time of amylase or lipase measurements (Figs. 2 and 3). Although 71% of grade I pancreatic injury patients had elevated amylase levels when measured

Results The trauma database identified 51 patients with traumatic pancreatic injury. Eleven patients did not meet inclusion criteria. Exclusion criteria eliminated fourteen patients: three patients with no laboratory data, two patients with penetrating injuries, and nine patients for whom a time of injury could not be determined. Five of the patients for whom no time of injury could be

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Fig. 1. Mechanism of injury.

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Table 1 Associated intra-abdominal injuries and operative intervention. Age

Gender

Pancreas injury grade

Associated intra-abdominal injury

OR

Pancreatic intervention

1y 1m

F

I

Grade V spleen laceration, left adrenal hematoma

Y

None

3y 1m

M

I

Small bowel mesenteric tear with degloved small bowel, bilateral retroperitoneal hematoma

Y

None

3y 9m

M

I

Small liver laceration

Y

None

4y 1m

M

I

Grade IV liver laceration

N

N/a

5y 1m

F

I

Grade III liver laceration, right adrenal hematoma

Y

None

5y 7m

M

I

Bilateral adrenal hematomas

Y

None

5y 8m

F

I

Right adrenal hematoma, mesenteric hematomas

Y

Drain placement

5y 8m

M

I

Grade II spleen laceration

N

N/a

6y 2m

M

I

Grade 2 Duodenal perforation, Fundus of stomach perforation with hematoma

Y

Drain placement

6y 3m

M

I

Duodenal serosal tear, right colon contusion, right adrenal hematoma

Y

Drain placement

7y 7m

M

I

Stellate liver laceration, Multiple spleen lacerations, right peri-nephric hematoma

Y

None

8y 11m

F

I

Grade III liver laceration with left biliary duct injury

Y

None

9y 4m

M

I

Right renal contusion, right adrenal hematoma

N

N/a

12y 8m

M

I

None

N

N/a

13y 1m

F

I

Grade V left kidney laceration, Grade IV spleen laceration

Y

Drain placement

2y 1m

F

II

Grade I liver laceration

Y

Drain placement

2y 4m

M

II

Grade I liver laceration, right adrenal hematoma

N

N/a

3y 6m

M

II

None

N

N/a

3y 10m

M

II

Splenic laceration at hilum

Y

Drain placement

4y 1m

M

II

None

N

N/a

5y 4m

F

II

Grade II liver laceration, Grade II spleen laceration

Y

Drain placement

5y 4m

M

II

Grade IV liver laceration and zone 2 right kidney hematoma

Y

Drain placement

7y

M

II

Duodenal hematoma

Y

Drain placement

7y 6m

M

II

None

N

N/a

12y 10m

M

II

None

N

N/a

11y 9m

M

V

Duodenal transection

Y

Pancreaticoduoden-ectomy

N/a = Not applicable

greater than 2 h post-injury compared to 25% of those measured earlier, this was not statistically significant using Fisher’s exact test (p = 0.132). Elevated levels were seen in all Grade II injury patients when measured at greater than 2 h compared to 50% of patients with levels measured earlier though not statistically significant (p = 0.286). The only patient with a grade V injury had a normal amylase level measured at less than 2 h post-injury. No statistically significant difference was found when comparing grade of pancreatic injury with time of lipase measurement (Fig. 3). Elevated lipase levels were seen in 80% of grade I patients measured at greater than 2 h post-injury compared to 37.5% of those measured earlier, although not significantly different by Fisher’s exact test (p = 0.226). All of grade II injury patients had elevated lipase levels regardless of time, thus no statistical tests were performed. The single patient with a grade V injury had an elevated lipase level that was measured at less than 2 h post-injury. Discussion The results indicate that in paediatric traumatic pancreatic injury, elevated amylase levels are seen in a significantly greater

number of patients when the measurement was obtained greater than 2 h post-injury, compared to measurements obtained earlier. A similar, but not statistically significant trend was seen with lipase measurements. Takashima et al noted a difference with values taken at greater than 3 h post-injury, but the data (Tables 2– 3) suggests using an earlier cut off at 2 h.23 Grade of pancreatic injury had no statistically significant difference on measurements. However, a trend was seen with more patients having elevated values when measured after 2 h post-injury. Smaller sample sizes from injury grade stratification may have prevented the detection of a difference. The clinical application of our findings suggests an alteration in subsequent surgical management. The likelihood of pancreatic injury may prompt more vigilant observation requiring admission rather than discharge home. Initial admission dietary orders might routinely be nothing by mouth while waiting for the optimal timeframe post-injury to obtain pancreatic enzyme levels. Activity restrictions may also be employed. Isolated amylase and lipase values are not cost-effective screening tools, but in conjunction with clinical findings additional ancillary studies may be justified.1

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Table 2 Serum amylase measurements at given time intervals. Time from injury to measurement (h) <1 1:01–2:00 2:01–3:00 3:01–4:00 4:01–5:00 5:01–6:00 6:01–7:00 7:01–8:00 >8 Total

Number of patients

Patients with elevated serum amylase levels

Patients with normal serum amylase levels

5 6 3 2 0 1 1 1 4

1 2 3 2 0 1 1 0 3

4 4 0 0 0 0 0 1 1

23

13

10

Patients with elevated serum lipase levels

Patients with normal serum lipase levels

h: hours

Table 3 Initial serum lipase measurements at given time intervals. Time from injury to measurement (h) <1 1:01–2:00 2:01–3:00 3:01–4:00 4:01–5:00 5:01–6:00 6:01–7:00 7:01–8:00 >8 Total

Number of patients

5 7 3 1 0 1 0 1 3

4 3 3 1 0 1 0 1 2

1 4 0 0 0 0 0 0 1

21

15

6

h: hours

Additional diagnostic studies may include CT scan, ultrasound, ERCP or magnetic resonance cholangiopancreatography (MRCP). CT scans are quick and are able to evaluate other organs in addition to the pancreas. However, CT scans can fail to detect pancreatic injury.2,4,14,15 Ultrasonography is useful for detecting pseudocysts, but is not sensitive to detect pancreatic injuries in the acute period.4 ERCP and MRCP have been suggested by some authors as a sensitive modality to detect pancreatic ductal injury.4,8,11

The management of pancreatic injuries in children varies among practitioners, but most often hinges on the severity of parenchymal injury and the possibility of main pancreatic duct injury. Most authors agree that non-operative management is acceptable in patients with grade I–II injuries, without major pancreatic ductal injury.6,12,18,19 Patients with grade III and IV injuries, which involve the major pancreatic duct, have a higher risk of mortality and complications that increases with delayed intervention, thus surgical management is usually advocated.6 The elevated amylase and lipase values along with physical findings may be helpful to prompt further diagnosis and intervention to prevent morbidity and mortality.

Fig. 2. Percentage of subjects with elevated amylase measurements by grade of injury and time of measurement.

Fig. 3. Percentage of subjects with elevated lipase measurements by grade of injury and time of measurement.

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Table 4 Mean and median values for amylase measurements by time & grade of injury. Time of measurement post-injury

Grade I pancreatic injury

Grade II pancreatic injury

(n = 15)

<2 h >2 h

(n = 7)

Grade V injury (n = 1)

Mean (U/L)

Median (U/L)

Mean (U/L)

Median (U/L)

Value (U/L)

80.25 154.9

59.5 133

113 475.4

113 542

102 N/A

Normal amylase values at our institution are 30–110 U/L.

Table 5 Mean and median values for lipase measurements by time & grade of injury. Time of measurement post-injury

<2 h >2 h

Grade I pancreatic injury

Grade II pancreatic Injury

Grade V injury

(n = 13)

(n = 7)

(n = 1)

Mean (U/L)

Median (U/L)

Mean (U/L)

Median (U/L)

Value (U/L)

443.1 705.6

274.5 584

1650.3 2505.75

1404 2553.5

1421 N/A

Normal lipase values at our institution are 114–300 U/L.

One study suggested a serum amylase value greater than 200 (U/L) and a serum lipase value greater than 1800 (U/L) along with physical exam findings, were useful cut-off values to detect patients more likely to have major pancreatic duct injuries.22 The single patient in our study with a grade V injury did not have values over these cut off levels, although the initial measurements were taken less than 2 h from the time of injury. The mean and median values for both enzymes were less than the aforementioned cut-off values in patients with grade I and II injuries when measured at 2 h or less post-injury (Tables 4–5). However, both mean and median enzyme values obtained at greater than 2 h post-injury in grade I and II injuries were above the designated cut-off values. Although using cut-off values with enzyme levels taken at 2 h or less appears to be clinically useful, caution should be taken in presuming major pancreatic duct injury in patients with values obtained greater than 2 h post-injury. It has been suggested that measurements taken more than 3 h after the time of injury could help differentiate grade I from grade III injuries.23 We were unable to confirm this observation due to the lack of higher grade injuries in our study population. However, analysis of measurements obtained greater than 2 h post-injury indicates at least a 3-fold increase in enzyme levels for both amylase and lipase between grade I and II injuries. We speculate that a greater difference in values would be seen with higher grades of injury. Missing patient and data values are inherent limitations when utilising a retrospective chart review design. Furthermore, our small sample size limited power to detect statistical significance. Elevated delayed values may also have elevated initial values, but since immediate baseline values were not drawn on those patients, we can only speculate that the initial values were low and subsequently rose. Fixed time periods to draw the enzyme levels would be helpful to standardise the measurements and to consistently follow any temporal trends in those measurements. Conclusions Traumatic pancreatic injury in the paediatric population is rare and difficult to diagnose. The timing of pancreatic enzyme measurements may be a valuable tool to help detect pancreatic injury. An amylase measurement obtained greater than 2 h postinjury may be more useful in detecting pancreatic injuries than an immediate measurement. A similar, but non-statistically significant trend was also seen with lipase levels. Further study is needed

whereby enzyme levels are drawn at fixed time periods to consistently follow any temporal trends in those measurements in patients with and without traumatic pancreatic injuries. Conflict of interest None of the authors have any financial or personal relationships that could inappropriately influence this original work. There are no outside funding sources or sponsors for this study. References 1. Adamson WT, Hebra A, Thomas PB, et al. Serum amylase and lipase alone are not cost-effective screening methods for pediatric pancreatic trauma. J Pediatr Surg 2003;38:354–7. 2. Akhrass R, Kim K. Computed tomography: an unreliable indicator of pancreatic trauma. Am Surgeon 1996;62:647–52. 3. Arkovitz MS, Johnson N, Garcia VF. Pancreatic trauma in children: mechanisms of injury. J Trauma 1997;42:49–53. 4. Bosboom D, Braam AWE, Blickman JG, et al. The role of imaging studies in pancreatic injury due to blunt abdominal trauma in children. Eur J Radiol 2006;59:3–7. 5. Boulanger BR, Milzman DP, Rosati C, et al. The clinical significance of acute hyperamylasemia after blunt trauma. Canad J Surg 1993;36:63–9. 6. Bradley 3rd EL, Young Jr PR, Chang MC, et al. Diagnosis and initial management of blunt pancreatic trauma: guidelines from a multiinstitutional review. Ann Surg 1998;227:861–9. 7. Buechter KJ, Arnold M, Steele B, et al. The use of serum amylase and lipase in evaluating and managing blunt abdominal trauma. Am Surgeon 1990;56: 204–8. 8. Canty Sr TG, Weinman D. Management of major pancreatic duct injuries in children. J Trauma 2001;50:1001–7. 9. Capraro AJ, Mooney D, Waltzman ML. The use of routine laboratory studies as screening tools in pediatric abdominal trauma. Pediatr Emerg Care 2006;22: 480–4. 10. Farkouth E, Wassef R, Atlas H, et al. Importance of the serum amylase level in patients with blunt abdominal trauma. Canadian J Surg 1982;25:626–8. 11. Firstenberg MS, Volsko TA, Sivit C, et al. Selective management of pediatric pancreatic injuries. J Pediatr Surg 1999;34:1142–7. 12. Holland AJA, Davey RB, Sparnon AL, et al. Traumatic pancreatitis: Long-term review of initial non-operative management in children. J Pediatr Child Health 1999;35:78–81. 13. Holmes JF, Sokolove PE, Land Catherine. et al. Identification of intra-abdominal injuries in children hospitalized following blunt torso trauma. Acad Emerg Med 1999;6:799–806. 14. Ilahi O, Bochicchio GV, Scalera TM. Efficacy of computed tomography in the diagnosis of pancreatic injury in adult blunt trauma patients: a single-institutional study. Am Surgeon 2002;68:704–8. 15. Jeffrey Jr RB, Federle MP, Crass RA. Computed tomography of pancreatic trauma. Radiology 1983;147:491–4. 16. Jobst MA, Canty Sr TG, Lynch FP. Management of pancreatic injury in pediatric blunt abdominal trauma. J Pediatr Surg 1999;34:818–24.

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