Utility of serum pancreatic enzyme levels in diagnosing blunt trauma to the pancreas: a prospective study with systematic review.

INTRODUCTION: Reliability of serum pancreatic enzyme levels in predicting pancreatic injuries has been a parameter of interest and the present recommendations on its utility are based primarily on anecdotal observations. The aim of this study was to evaluate the utility of serum pancreatic enzyme assessment in predicting blunt pancreatic injury with imaging and surgical correlation and compare our results with a systematic review of literature till date. METHODS: A prospective cohort study conducted over 4 years in a tertiary care referral centre with 164 consecutive patients who presented to the emergency department with a history of blunt abdominal trauma and had serum pancreatic enzyme assessment, USG and subsequent diagnostic CECT were analyzed. The CT findings and AAST grade of pancreatic injury, various intra-abdominal injuries and time elapsed since injury and other associated factors were correlated with serum pancreatic enzyme levels. For systematic review of literature MEDLINE database was searched between 1940 and 2012, also the related citations and bibliographies of relevant articles were analyzed and 40 articles were included for review. We compared our results with the systematic critique of literature till date to formulate recommendations. RESULTS: 33(21%) patients had pancreatic injury documented on CT and were graded according to AAST. Statistically significant elevated serum amylase levels were observed in patients with pancreatic and bowel injuries. However, elevated serum lipase was observed specifically in patients with pancreatic injury with or without bowel injury. Combined serum amylase and lipase showed 100% specificity, 85% sensitivity in predicting pancreatic injury. Elevated (n=28, 85%) vs. normal (n=5, 15%) serum amylase and lipase levels showed sole statistically significant association with time elapse since injury to admission, with a cutoff of 3h. CONCLUSIONS: Based on our results and the systematic review of the literature till date we conclude, persistently elevated or rising combined estimation of serum amylase and lipase levels are reliable indicators of pancreatic injury and is time dependent, nondiagnostic within 6h or less after trauma. In resource constrained countries where CT is not available everywhere it may support a clinical suspicion of pancreatic injury and can be reliable and cost-effective as a screening tool.

Utility of hepatic transaminases in children with concern for abuse.

OBJECTIVE: Routine testing of hepatic transaminases, amylase, and lipase has been recommended for all children evaluated for physical abuse, but rates of screening are widely variable, even among abuse specialists, and data for amylase and lipase testing are lacking. A previous study of screening in centers that endorsed routine transaminase screening suggested that using a transaminase threshold of 80 IU/L could improve injury detection. Our objectives were to prospectively validate the test characteristics of the 80-IU/L threshold and to determine the utility of amylase and lipase to detect occult abdominal injury. METHODS: This was a retrospective secondary analysis of the Examining Siblings To Recognize Abuse research network, a multicenter study in children younger than 10 years old who underwent subspecialty evaluation for physical abuse. We determined rates of identified abdominal injuries and results of transaminase, amylase, and lipase testing. Screening studies were compared by using basic test characteristics (sensitivity, specificity) and the area under the receiver operating characteristic curve. RESULTS: Abdominal injuries were identified in 82 of 2890 subjects (2.8%; 95% confidence interval: 2.3%-3.5%). Hepatic transaminases were obtained in 1538 (53%) subjects. Hepatic transaminases had an area under the receiver operating characteristic curve of 0.87. A threshold of 80 IU/L yielded sensitivity of 83.8% and specificity of 83.1%. The areas under the curve for amylase and lipase were 0.67 and 0.72, respectively. CONCLUSIONS: Children evaluated for physical abuse with transaminase levels >80 IU/L should undergo definitive testing for abdominal injury.

Intraabdominal adhesion formation is associated with differential mRNA expression of metabolic genes PDHb and SDHa.

PURPOSE: Intraabdominal adhesions represent a major cause of postoperative morbidity potentially causing pain, small bowl obstruction and infertility. The process of adhesion formation might be regarded as an ischemic disease. Under hypoxic conditions, metabolic enzymes are regulated via hypoxic responsive elements by the hypoxia-inducible factor 1 (HIF-1). We therefore investigated the gene expression of HIF-1 and two pivotal metabolic genes, pyruvate-dehydrogenaseß (PDHb) and succinate-dehydrogenase-complex-subunit-A (SDHa) in a validated ischemia model of adhesion formation. METHODS: Peritoneal adhesions were created using an ischemic button model in female Wistar rats. Expression levels of HIF-1α/ß, PDHb and SDHa in adhesiogenic versus native peritoneum were analyzed using quantitative PCR on the third post-operative day. RESULTS: Gene expression of HIF-1α was up-regulated by 10 % (p = 0.003), PDHb was up-regulated by 23 % (p = 0.0004) and SDHa (p = 0.0005) was up-regulated by 24 % in the adhesiogenic peritoneum compared to native peritoneum. The expression level of HIF-1ß was not significantly influenced by adhesion formation. CONCLUSION: The increased expression level of HIF-1α in the peritoneal tissue of ischemic buttons associated with postsurgical adhesions supports the major role for hypoxia in influencing peritoneal expression patterns of genes involved in the process of adhesion formation. As pivotal metabolic genes are upregulated, this seems to be an anabolic process associated with increased cellular metabolism.

Utility of hepatic transaminases to recognize abuse in children.

OBJECTIVE: Although experts recommend routine screening of hepatic transaminases (aspartate aminotransferase [AST] and alanine aminotransferase [ALT]) in cases of potential child physical abuse, this practice is highly variable. Our objective was to determine the sensitivity and specificity of routine transaminase testing in young children who underwent consultation for physical abuse. PATIENTS AND METHODS: This was a prospective, multicenter, observational study of all children younger than 60 months referred for subspecialty evaluation of possible physical abuse. The child abuse team at each center recommended screening transaminases routinely as standard of care for all cases with a reasonable concern for physical abuse. Sensitivity and specificity for transaminases and clinical examination findings to detect identified abdominal injuries were determined, and receiver operating characteristic analysis was undertaken. RESULTS: Of 1676 consultations, 1272 (76%) patients underwent transaminase testing, and 54 (3.2% [95% confidence interval: 2.4-4.2]) had identified abdominal injuries. Area under the curve for the highest level of either transaminase was 0.85. Using a threshold level of 80 IU/L for either AST or ALT yielded a sensitivity of 77% and a specificity of 82% (positive likelihood ratio: 4.3; negative likelihood ratio: 0.3). Of injuries with elevated transaminase levels, 14 (26%) were clinically occult, lacking abdominal bruising, tenderness, and distention. Several clinical findings used to predict abdominal injury had high specificity but low sensitivity. CONCLUSIONS: In the population of children with concern for physical abuse, abdominal injury is an important cause of morbidity and mortality, but it is not so common as to warrant universal imaging. Abdominal imaging should be considered for potentially abused children when either the AST or ALT level is >80 IU/L or with abdominal bruising, distention, or tenderness.

Hepatic enzymes have a role in the diagnosis of hepatic injury after blunt abdominal trauma.

INTRODUCTION: Delayed diagnosis of patients with severe liver injuries is associated with an adverse outcome. As computed tomographic (CT) scan is not always available in the management of blunt abdominal trauma worldwide, the present study was undertaken to determine the accuracy of selected haematological markers in predicting the presence of hepatic injury and its severity after blunt abdominal trauma. METHODS: A retrospective review of all patients with blunt abdominal trauma presented to our institution over a 3-year period was performed. Patients were excluded if they suffered penetrating injuries, died in the emergency department or if the required blood tests were not performed within 24h of the accident. The grading of the hepatic injury was verified using CT scans or surgical findings. RESULTS: Ninety-nine patients with blunt abdominal trauma had the required blood tests performed and were included in the study. The median injury severity score was 24 (range 4-75). Fifty-five patients had hepatic injuries, of which 47.3% were minor (Grades I and II) while 52.7% had major hepatic injuries (Grades III-V). There were no patients with Grade VI injuries. A raised ALT was strongly associated with presence of hepatic injuries (OR, 109.8; 95% CI, 25.81-466.9). This relation was also seen in patients with raised AST>2 times (OR, 21.33; 95% CI, 7.27-62.65). This difference was not seen in both bilirubin and ALP. ALT>2 times normal was associated with major hepatic injuries (OR, 7.15; 95% CI, 1.38-37.14; p=0.012) while patients with simultaneous raised AST>2 times and ALT>2 times had a stronger association for major hepatic injuries (OR, 8.44; 95% CI, 1.64-43.47). CONCLUSION: Abnormal transaminases levels are associated with hepatic injuries after blunt abdominal trauma. Patients with ALT and AST>2 times normal should be assumed to possess major hepatic trauma and managed accordingly. Patients with normal ALT, AST and LDH are unlikely to have major liver injuries.

Hepatic enzyme decline after pediatric blunt trauma: a tool for timing child abuse?

OBJECTIVES: Previous research in adult patients with blunt hepatic injuries has suggested a pattern of serum hepatic transaminase concentration decline. Evaluating this decline after pediatric blunt hepatic trauma could establish parameters for estimating the time of inflicted injuries. Deviation from a consistent transaminase resolution pattern could indicate a developing complication. METHODS: Retrospective review of pediatric patients with injuries including blunt liver trauma admitted to one of four urban level 1 trauma centers from 1990 to 2000. Cases were excluded for shock, death within 48 h, complications, or inability to determine injury time. Transaminase concentration decline was modeled by individual patients, by injury grade, and as a ratio with regard to injury time. RESULTS: One hundred and seventy-six patients met inclusion criteria. The rate of aspartate aminotransferase (AST) clearance changed significantly over time. Alanine aminotransferase (ALT) fell more slowly. Of the 118 patients who had multiple measurements of AST, for 112 (95%) the first concentration obtained was the highest. When ALT was greater than AST, the injury was older than 12h (97% specificity (95% CI, 95-99%), sensitivity 42% (95% CI, 33-50%)). Patients with enzymes that rose after 14 h post-injury were more likely to develop complications (RR=24, 95% CI 10-58). CONCLUSIONS: Hepatic transaminases rise rapidly after uncomplicated blunt liver injury, then fall predictably. Persistently stable or increasing concentrations may indicate complications. ALT>AST indicates subacute injury.

Trauma-hemorrhage inhibits splenic dendritic cell proinflammatory cytokine production via a mitogen-activated protein kinase process.

Although splenic dendritic cell (DC) functions are markedly altered following trauma-hemorrhage, the mechanism(s) responsible for the altered DC functions remains unknown. We hypothesized that trauma-hemorrhage inhibits DC function via suppressing toll-like receptor 4 (TLR4) expression and mitogen-activated protein kinases (MAPKs). To examine this, male C3H/HeN (6-8 wk) mice were randomly assigned to sham operation or trauma-hemorrhage. Trauma-hemorrhage was induced by midline laparotomy and approximately 90 min of hypotension [blood pressure (BP) 35 mmHg], followed by fluid resuscitation (4x the shed blood volume in the form of Ringer lactate). Two hours later, mice were euthanized, splenic DCs were isolated, and the changes in their MAPK activation, TLR4-MD-2 expression, and ability to produce cytokines were measured. The results indicate that trauma-hemorrhage downregulated the lipopolysaccharide (LPS)-induced MAPK activation in splenic DCs. In addition to the decrease in MAPK activation, surface expression of TLR4-MD-2 was suppressed following trauma-hemorrhage. Furthermore, LPS-induced cytokine production from splenic DCs was also suppressed following trauma-hemorrhage. These findings thus suggest that the decrease in TLR4-MD-2 and MAPK activation may contribute to the LPS hyporesponsiveness of splenic DCs following trauma-hemorrhage. Hyporesponsiveness of splenic DCs was also found after stimulation with the TLR2 agonist zymosan. Our results may thus explain the profound immunosuppression that is known to occur under those conditions.

Study on oxidative stress in patients with abdominal trauma.

Reactive oxygen species have been implicated in the etiology of multiple organ dyspepsia syndrome and infection's complications in patients with trauma. But the oxidative stress and antioxidants levels in abdominal trauma have not yet been studied. Therefore, this study was planned to measure lipid peroxidation for oxidative stress and reduced glutathione, catalase and superoxide dismutase (SOD) for antioxidant levels in plasma & heamolysate of 30 patients with abdominal trauma and 30 controls. From this study we can summarize that there was an increase in oxidative stress and decrease in antioxidant levels (causing oxidative stress) on day zero in patients with abdominal trauma. This oxidative stress on day zero was not related to the development of complications. There was no significant difference in oxidative stress between patients with solitary and multiple abdominal organ injury and also between patients with hollow viscus injury and solid organ injury on day zero. From this study, we conclude that in patients with abdominal trauma there was increase in oxidative stress and decrease in antioxidant levels on day zero.

Comparison of lipase activity in peritoneal fluid of dogs with different pathologies--a complementary diagnostic tool in acute pancreatitis?

A clinical diagnosis of acute pancreatitis is often difficult to obtain. Histopathology remains the gold standard, whereas clinical signs, diagnostic imaging and laboratory testing, even in combination, may be insufficient. In a prospective study, lipase activity in ascitic fluid of various aetiologies was determined in 44 dogs in order to investigate its performance in cases of acute pancreatitis. Data of simultaneously determined blood lipase activities were available in 27 dogs. Lipase activity was measured by a colorimetric assay. A complete peritoneal fluid analysis was performed. Dogs were divided into four groups, according to their final diagnosis: acute pancreatitis (A), abdominal trauma (B), abdominal neoplasia (C) and others (hepatic or cardiac diseases) (D). Dogs with acute pancreatitis had a significantly higher peritoneal lipase activity than those in other groups (P < or = 0.024), while no significant difference was found between the other groups (P > or = 0.734). Blood lipase activity as well as protein content and total cell count of the ascitic fluid did not show any significant difference between groups. Data show that determination of lipase activity in dogs that develop ascites may be useful in complementing the diagnosis of acute pancreatitis.

Examination of the role of abdominal computed tomography in the evaluation of victims of trauma with increased aspartate aminotransferase in the era of focused abdominal sonography for trauma.

BACKGROUND: Current evaluation of patients with negative findings on a focused abdominal sonography for trauma scan and an isolated increase of admission hepatic enzymes includes abdominal computed tomography (CT). Many of these patients do not have clinically important hepatic injuries. The purpose of this study was to establish the admission aspartate aminotransferase (AST) level below which patients do not need an abdominal CT for injury evaluation and treatment. METHODS: Patients who were hemodynamically stable, had a focused abdominal sonography for trauma scan with negative findings, and an AST level greater than 200 IU/L were identified over a 1-year period. Medical records were reviewed for demographics, injuries sustained, mechanism, evaluation, interventions, and complications. RESULTS: A total of 67 patients, mostly with blunt trauma, were identified; 42 (63%) had an AST level < 360 IU/L, and 25 (37%) had an AST level > 360 IU/L. Patients with an AST level > 360 IU/L had a 88% chance of having any hepatic injury and a 44% chance of having an injury of grade III or greater (P =.0001). Patients with an AST level of < 360 IU/L only had a 14% chance of having a liver injury and no chance of having an injury of grade III or greater (P =.036). CONCLUSIONS: Clinically important hepatic injuries are not missed if an abdominal CT is only performed for patients with a focused abdominal sonography for trauma scan with negative findings and an AST level of > 360 IU/L. Eliminating unnecessary CT allows for more cost-effective use of resources.

Liver enzymes as predictors of liver damage due to blunt abdominal trauma in children.

BACKGROUND: Blunt abdominal trauma in children can result in injury to the liver. In hemodynamically stable patients, initial evaluation of liver transaminase levels may be useful in determining the need for computed tomography (CT). METHODS: We reviewed the medical records of 44 hemodynamically stable children who had abdominal CT and who also had liver enzyme determinations as the initial workup. RESULTS: Liver enzymes were found to be elevated in all but one patient with CT confirmed hepatic injury. The sensitivity and specificity of elevated liver enzyme levels were 92.9% and 100%, respectively, for predicting liver injury. CONCLUSION: When hemodynamically stable pediatric patients with blunt abdominal trauma have AST levels >400 and/or ALT levels >250 IU/L, abdominal CT is indicated. Children in this study with serum transaminase levels below these values were at decreased risk of liver injury.

Nitric oxide synthase isoform expression in a porcine model of granulation tissue formation.

BACKGROUND: This study was designed to determine whether the nitric oxide (NO) pathway is involved in wound granulation tissue formation. METHODS: A section of the pig abdominal wall (excluding the skin) was excised, creating an incisional hernia. The resulting defect was repaired with silicone sheeting in a manner that mimics a temporary abdominal wall closure. During the 14-day experimental period, porcine omentum adhered to the peritoneal edges of the defect and a highly vascularized granulation tissue formed on both sides of the sheeting. Granulation tissue thickness and wound fluid volume were monitored by ultrasonography and epigastric artery flow velocity was monitored by color Doppler flow analysis at days 2, 4, 7, 9, 11, and 14. Fluid was serially harvested from the wound compartment at days 2, 4, 7, 9, 11, and 14 for nitrite/ nitrate (NOx) analysis. Finally, granulation tissue was harvested at day 14 for immunohistochemical and molecular analyses. RESULTS: There was a significant increase in granulation tissue thickness and wound fluid volume during the 14-day study period. Blood flow to the wound increased significantly by day 4 and returned toward baseline by day 14. Wound fluid NOx levels significantly increased from days 7 to 11 and then decreased to near baseline values by day 14. Wound fluid arginine levels significantly decreased when compared with peritoneal fluid and plasma levels at day 14, while wound fluid ornithine levels significantly increased. Immunohistochemical analysis of granulation tissue at day 14 revealed nitric oxide synthase (NOS) 2 was present in the majority of the cells in the granulation tissue. NOS 3 was expressed in endothelial cells only, and NOS 1 expression was not observed in the granulation tissue. CONCLUSIONS: This study suggests that NO, NOS 2, and arginine may play critical roles in granulation tissue formation and wound healing. Arginase and NOS 2 may compete for available arginine as a substrate, thereby limiting later NO production in favor of sustained ornithine synthesis.

Serum amylase determinations in pediatric patients presenting to the ED with acute abdominal pain or trauma.

The objective of this study was to evaluate the overall impact of serum amylase determinations in the initial management of patients presenting to the pediatric emergency department (ED) with the acute onset of abdominal pain or trauma. All cases of patients younger than 18 years of age who presented to the pediatric ED for whom a serum amylase value was determined during an 18-month period were reviewed. Data were collected retrospectively, including serum amylase concentration, age, gender, presenting complaint, discharge/admission status, diagnosis, and discharge plans or inpatient management to evaluate the impact of serum amylase determinations. Seven hundred twenty-three cases were reviewed during the study period. Six hundred fifty-six patients met study criteria, with 385 serum amylase determinations performed for the evaluation of acute abdominal pain and 271 for acute trauma. Sixty-seven serum amylase determinations were also sent for other reasons. Overall, 12 of 656 study patients had elevated amylase levels (1.8%) during the study period (range, 130 to 2318 U/L). Eight of 271 amylase levels sent to the laboratory for trauma (3.0%), and 4 of 385 sent for abdominal pain (1.0%) were elevated. Overall, serum amylase concentration had no influence on whether or not the patient was admitted to the hospital. Of the 12 patients with elevated amylase levels sent for abdominal pain or trauma, only 2 had their clinical management affected by the serum amylase concentration. In both cases, the patient presented with subacute abdominal pain related to significant abdominal trauma that had occurred 2 to 3 weeks earlier. Both patients showed evidence of pancreatic insult with diagnostic imaging studies.(ABSTRACT TRUNCATED AT 250 WORDS)

Peritoneal lavage enzyme determinations following blunt and penetrating abdominal trauma.

Diagnostic peritoneal lavage (DPL) provides a rapid and sensitive means of investigating the peritoneal cavity following blunt and penetrating trauma. However, its shortcomings include insensitivity in the early identification of isolated hollow viscus injuries. We have routinely assayed lavage amylase (LAM) and alkaline phosphatase (LAP) in acutely injured patients for more than 4 years to assess the contribution of lavage enzyme analysis to the overall accuracy of DPL. From 1,969 DPLs, LAM was analyzed in 1,881 (96%) and LAP in 1,734 (88%) of 1,536 blunt and 433 penetrating trauma cases. Of 28 patients with negative lavage by LRBC but LAM greater than or equal to 20 IU/L, 13 (46%) had clinically significant injury requiring laparotomy. Seventy-seven percent of these cases involved the small bowel. In this group, LAM greater than or equal to 20 IU/L had a sensitivity of 87%, specificity of 75%, and positive predictive value of 46% for significant intra-abdominal injury. Seven patients had LAM greater than or equal to 20 IU/L and LAP greater than or equal to 3 IU/L. These values had a sensitivity of 54%, specificity of 98%, and positive predictive value of 88% for significant abdominal injury. Elevations of LAM (greater than or equal to 20 IU/L) and LAP (greater than or equal to 3 IU/L) mandate laparotomy where the history is consistent with possible small bowel injury. Elevation of either enzyme alone should raise the suspicion of hollow visceral organ injury and warrant close observation.

The use of serum amylase and lipase in evaluating and managing blunt abdominal trauma.

In order to determine the usefulness of serum amylase and lipase in the initial evaluation and subsequent management of blunt abdominal trauma (BAT) patients, we collected serum amylase and lipase on 85 consecutive BAT patients at admission, hospital day 1, hospital day 3, and hospital day 7. Only one patient had a pancreatic injury. A total of 45 patients (53%) had at least one enzyme abnormality during the study. There was no correlation between amylase or lipase values and age, sex, type of injury, diagnostic tests, operation, and outcome. In a control group of nonabdominal-trauma patients with admit studies only, all enzyme values were normal. We conclude that serum amylase and lipase are randomly elevated in patients with nonpancreatic-BAT both initially and during subsequent hospitalization and are not useful clinical tools in these patients.

[Usefulness and problems of peritoneal tap & lavage on the diagnosis of blunt abdominal trauma--efficacy for diagnosis of intestinal injury].

It is difficult to diagnose blunt intestinal injury, despite of the progress of radiological diagnostic procedures, if patient has an altered mental status or an associated injury which hampers abdominal physical findings. So we conducted a prostective study about usefulness of peritoneal tap and lavage on the diagnosis of blunt abdominal injury. From September 1987 to August 1988 we performed peritoneal lavage in 36 patients and investigated the diagnostic accuracy of this method for detecting each organ injuries. We adopted conventional criteria "RBC greater than or equal to 100000/mm3, WBC greater than or equal to 500/mm3" and also employed new supplementary criteria "WBC greater than or equal to RBC/150 (if RBC/is positive), Amylase or Alkaline phosphatase greater than or equal to RBC/10000, GOT or GPT greater than or equal to RBC/40000". The diagnostic accuracy rates were 1) intestinal injury: WBC-sensitivdty (se) 75%, Specificity (sp) 100% 2) small intestinal injury; AMY-se 100%, sp 90%, Alp-se 100%, sp 100% 3) hepatic injury; GOT or GPT-se 100%, sp 91%. These satisfactory results can be obtained by employment of the new supplementary criteria. Peritoneal tap and lavage is easy to perform but is sometimes found to have poor fluid return. So we recommend to adopt the authentic method of peritoneal lavage. We concluded from this study that if these new supplementary criteria are employed peritoneal lavage can be useful to diagnose blunt intestinal injury.

Phospholipase A--a parameter of sepsis? A comparison of PLA and Stevens' Sepsis Severity Score.

Phospholipase A (PLA) and Sepsis Severity Score (SSS) were measured regularly in 28 patients with sepsis (n = 11), pancreatic operations (n = 7), or multitrauma combined with contused abdominal trauma (n = 10). No linear correlation was found between these two parameters. A statistical correlation could be shown for the paired values PLAmax/SSS or PLA/SSSmax. They lie together above or below their "critical value" of 20 points SSS or 30 U/l PLA (alpha less than 0.05). The evaluation of mortality shows a distinctly higher significance for the SSS (P less than 0.01) in comparison with the PLA (P less than 0.05). In certain cases PLA was the first parameter which could have shown the beginning of a septic process.

Importance of the serum amylase level in patients with blunt abdominal trauma.

Possible intra-abdominal injuries were sought in 101 patients admitted with blunt abdominal trauma. The serum amylase level was measured in the first 12 hours after the accident. Twenty-five patients had hyperamylasemia; 18 underwent laparotomy and 7 were treated conservatively. At laparotomy all 18 patients exhibited at least one serious intra-abdominal lesion, and there was a total of 28 lesions in the who group (including only four pancreatic injuries). The mean value of the serum amylase for those who had laparotomy was 1190 IU, while it was only 363 IU for those not operated upon. The authors conclude that hyperamylasemia in blunt abdominal trauma is not specific to pancreatic injury, but may suggest the presence of a serious intra-abdominal lesion.

Value of quantitative cell count and amylase activity of peritoneal lavage fluid.

From January 1974 through July 1979, 1,588 patients underwent diagnostic peritoneal lavage. The test had an accuracy of 98.6%, sensitivity of 94.3%, and specificity of 99.8%. It was true positive in 21.9%, false positive in 0.1%, false negative in 1.3%, and true negative in 76.6%. Fifty-nine patients from the true-positive group had grossly equivocal tests, but had positive lavage results based on quantitative cell count. Thus without cell count the test would have a sensitivity of 78.3%, accuracy of 94.8%, and specificity of 99.8. Eight patients had positive lavage based on WBC count but negative RBC count; all of these patients had bowel injuries. Measurement of lavage fluid amylase resulted in minimal or no improvement in the accuracy (0.06%), sensitivity (0.3%), or specificity (0.0%). Five of six patients with positive amylase levels but grossly negative tests had concomitant positive WBC count. The added cost of the amylase measurement is estimated to be $154,472. Peritoneal lavage has high accuracy, sensitivity, and specificity. Cell counts significantly improve sensitivity. Patients with a grossly equivocal test but with a positive cell count should undergo laparotomy. The lavage-fluid amylase measurement is costly and is of insignificantly yield.

Hyperamylasemia in critically injured patients.

We found that in traumatic shock patients without pancreatic injury, hyperamylasemia occurs in high frequency [49 of 61 (80%)]. Isoenzyme studies of 19 of these patients revealed 18 of them (94%) to have the salivary type of hyperamylasemia. Further, based on the results of the present study, the salivary gland as the organ of origin and the permeability of its cell membranes are suggested as the mechanism for traumatic hyperamylasemia.