March 2007 Vol 7 Isuue 1 FINAL without suicide .indd SULTAN QABOOS UNIVERSITY MEDICAL JOURNAL APRIL 2007 VOL 7, NO. 1 SULTAN QABOOS UNIVERSITY© Department of General Surgery and Radiology, Roya; Medical Services P O Box 849, Princess Haya Hospital, Aqaba, Jordan. *To whom correspondence should be addressed. Email: mazenonline64@yahoo.com The Role of Computed Tomography in Blunt Abdominal Trauma *Mazen I Hamidi, Khalid M Aldaoud, Izzeddin Qtaish ABSTRACT Objective: To determine the utility of the computed tomography (CT) scan in blunt abdominal trauma and to compare it with operative findings or clinical outcomes. Methods: A retrospective analysis based on existing, diagnostic CT scan reports taken during a 5 year period from 245 consecutive patients with blunt abdominal trauma. Percentages and types of trauma identified were based on CT scan findings. Recorded data included age, sex, type of injuries and scan results. The CT findings were compared and correlated with the operative findings, or clinical follow-up in conservatively managed cases. Results: Of the total of 245 patients, 3 (46%) underwent surgery. One hundred and thirty two (54%) patients were conservatively managed. There were 2 (4.9%) deaths. Hemoperitoneum were detected in 70 patients. All 52 patients with small hemoperitoneum on CT scan were conservatively man- aged and all 22 patients with large hemoperitoneum required surgical exploration. There were 95 splenic, 63 renal, 48 hepatic and 3 pancreatic injuries. Twenty one patients had bowel injuries. Five patients had vascular injuries. Twenty three patients had multi-organ injuries. Organ injuries were graded using the OIS (Organ Injury Scale) guidelines. Conclusion: In conjunction with close clinical monitoring, CT was reliable in the evaluation of blunt abdominal trauma in a selected group of patients, with overall sensitivity of 97% and specificity of about 95%. Positive predictive value 82% and negative predictive value 00%. Key words: Blunt abdominal trauma, CT scan. عن الكشف في ب) َوسَ احملُ يّ عِ طَ املَقْ رُّسٌ (التَفَ املقطعية االشعة دور ليلَة الكَ البطن اصابات الدين قطيش وعز الداوود خالد احلميدي، مازن بعد ما بنتائج ومقارنتها الكليلة البطن اصابات ــف في كش ب) َوسَ احملُ يّ عِ طَ َقْ امل رُّسٌ (ألتَفَ املقطعية ــعة االش ــتعماالت اس امللخص: الهدف: حتديد البطن الصابات 245 مريضا تعرضوا نتائج مت مقارنة التحليلية ــتعادية ــة االس الدراس الطريقة: في هذه ــريرية. الس التداخالت اجلراحية والفحوص املقطعية، ومت االشعة نتائج على اعتمادا حتديدها مت فقد املئوية ــبتها ونس االصابة نوع اما .(2004 1999الى (من ــنوات س الكليلة خالل فترة خمس العمليات في التي شوهدت تلك املقطعية مع االشعة من عليها حصلنا التي النتائج .قارنا االصابة ونوع واجلنس العمر مثل االخرى املعلومات تسجيل ،(46%) 113 جراحيا معاجلة مت 245 مريضا, مجموع : من النتائج . حتفظيا عوجلت التي للحاالت زبارات املتابعة أو املالحظات السريربة في اجلراحية، ــيمهم تقس 170 مريضا،حيث مت عند جوفي نزف عن ــف مت الكش 12 حالة وفاة. هناك كان . . حتفظية (54% – 132) الباقني معاجلة كانت بينما حتفظيا, معاجلتهم ومت 52 مريضا، في خفيفة االصابة كانت حيث ،( ــديد وش ــط متوس خفيف, ) اجلوفي النزف كمية حيث من مجموعات ثالث الى 63 اصابة , 95 اصابة طحال يلي: كما ــاب املص العضو حيث من االصابات كانت . جراحيا معاجلتهم 22 مريضا ومت في ــديدة ش ــت االصابة كان ــا بينم 23 مريضا. في عضو من ــر أكث في كانت االصابة . جوفية اصابات وعائية ــس خم و معوية 21 اصابة , بنكرياس 13 اصابة , ــد كب ــة 48 اصاب , ــى كل عن ــف الكش في موثوق بها كانت املقطعية ــعة االش نتائج ان تبني التداخالت اجلراحية ونتائج ــريرية الس الفحوصات نتائج مع اخلالصة: باملقارنة %82 والقيمة فكانت املوجبة ــة التنبؤي القيمة أما .95% وصلت الى ــة نوعية %97 ودق الى وصلت ــية بحساس اجلوفية الداخلية االعضاء ــات اصاب .100% التنبؤية السلبية البطن. املقطعية،اصابات االشعة الكلمات: مفتاح C L I N I C A L & B A S I C R E S E A R C H 42 M A Z E N I H A M I D I , K H A L I D M A L D A O U D , I Z Z E D D I N Q TA I S H THE CARE OF THE TRAUMA PATIENT IS demanding and requires speed and efficien-cy. Evaluating patients who have sustained blunt abdominal trauma (BAT) remains one of the most challenging and resource-intensive aspects of acute trauma care. Missed intra-abdominal injuries continue to cause preventable deaths. Physical exami- nation findings are notoriously unreliable for several reasons; a few examples are the presence of distracting injuries, an altered mental state, and drug and alcohol intoxication in the patient. Coordinating trauma re- suscitation demands a thorough understanding of the pathophysiology of trauma and shock, excellent clini- cal and diagnostic acumen, skill with complex proce- dures, compassion and the ability to think rationally in a chaotic milieu. BAT usually results from motor vehicle collisions, assaults, recreational accidents, or falls. Men tend to be affected slightly more often than women. The most commonly injured organs are the spleen, liver, retroperitoneum, small bowel, kidneys, bladder, colorectum, diaphragm, and pancreas. The CT scan remains the criterion standard for the detection of solid organ injuries.1 In addition, a CT scan of the abdomen can reveal other associated inju- ries, notably vertebral and pelvic fractures and injuries in the thoracic cavity. CT scans, unlike direct peritoneal lavage (DPL) or Focused Assessment with Sonography for Trauma (FAST) examinations, have the capability to determine the source of haemorrhage. In addition, many retro- peritoneal injuries go unnoticed with DPL and FAST examinations. CT scans provide excellent imaging of the pancre- as, duodenum and genitourinary system. The images can help quantitate the amount of blood in the abdo- men and can reveal individual organs with precision. The limitations of CT scans include marginal sensitiv- ity for diagnosing diaphragmatic, pancreatic and hol- low viscus injuries. Also, they are relatively expensive and time consuming and require oral or intravenous contrast, which may cause adverse reactions. 2, 3 M E T H O D S In this retrospective study, over a period of 5 years (from May 1999 to March 2004), we used abdomen CT scan reports available within the clinical charts of 245 patients with BAT, who were stable enough to undergo radiological investigation in Prince Hashem Hospital in Zarqa, Jordan. The patients included 171 (70%) males and 74 (30%) females. The age range was 14 - 72 years. Diagnostic peritoneal tapping was not performed in any of them. Patients with a normal CT scan and patients who either did not require admission, or who were discharged after a short, uneventful (max. 3 day) observation period without any further investigation, were excluded from the study. All CT scans were obtained with a Hi Speed Dual Helical CT scanner from General Electric. A single breath-hold helical scan from the top of the T12 verte- bral body to the pubic symphysis was obtained by us- ing 5-mm beam collimation and 8 mm/sec table speed (pitch, 1.6; 120 kVp; 240–270 mAs). Routine oral (or through nasogastric tube) contrast agents in the form of 1-2% diluted ionic iodinated contrast were given 30-40 minutes before the study. Oral contrast was not given to 23 patients with repeated vomiting or when limited information was required before proceeding for prompt laparotomy. All patients received intra- venous bolus of iodinated contrast agents. Following completion of the examination, the CT images were immediately reviewed by two specialist radiologists. They were in agreement on all the findings. Delayed CT scans were also incorporated whenev- Figures 1-3: Patient with multi organ injury: Grade V renal injury and shattered spleen. Note: The 3D reformat of CT-angio with complete loss of renal vascularisation (left) 43 TH E R O L E O F C O M P U T E D TO M O G R A P H Y I N B L U N T A B D O M I N A L TR AU M A er there was suspicion of kidney or urinary tract injury. Follow up CT scans were obtained for 14 patients, as dictated by the clinical course of the patient, but they did not contribute any further information. Hemoperitoneum on CT was graded as described by Federle and Jeffrey et al. 4 [Table 1]. Individual or- gan injuries were graded according to the OIS (Organ Injury Scale) system.5, 15 The OIS classification scheme is fundamentally an anatomic description, scaled from 1 to 5, representing the least to the most severe injury, ie. from simple organic contusion to avascularisation of one organ. CT findings were compared with opera- tive findings in 113 patients, and with the clinical out- come and follow-up in 132 conservatively managed patients. The results were analysed with respect to hemoperitoneum quantification and OIS grades. The overall imaging findings were analysed for their role in guiding the therapeutic options, whether conservative or surgical. R E S U L T S Of the 245 patients with blunt trauma, road traffic ac- cident was the commonest mode of injury and it was the cause of abdominal trauma in 186 patients. In 40 patients, the injury was caused by fall from height. Nineteen patients had blunt injuries from other mis- cellaneous causes. Of the total of 245 patients, 113 (46%) underwent surgery and 132 (54%) patients were conservatively managed without any complications. There were 12 deaths, three of which were related to postoperative complications. The other nine patients died of associ- ated head injuries within 24 hours. No autopsy results were available. Hemoperitoneum was detected in (69.4%) patients and they were divided into three groups according to the Federle and Jeffrey system4 [Table 1]. There were 52 ‘small’ patients, 96 ‘moderate’ patients and 22 ‘large’ patients [Table 2]. All 52 patients with small fluid hemoperitoneum on CT were conservatively man- aged and all 22 patients with large hemoperitoneum required surgical exploration. In the moderate fluid group, 50 patients were managed conservatively and the other 46 patients that were either unstable haemo- dynamically and/or had unexplained abdominal rigid- ity and/or packed-cell volume (PCV) drop were surgi- cally explored. Thus the rate of therapeutic laparotomy in patients with moderate hemoperitoneum shown on the CT scan was 52%. Among the solid organ injuries, the spleen was the commonest organ involved. There were 95 (38.8%) splenic, 63 (25.7%) renal, 48 (19.6%) hepatic and 13 (5.3%) pancreatic injuries. Twenty one (8.6%) patients had bowel injuries. Five (2%) patients had vascular in- juries. Twenty three patients had multi-organ injuries [Figs. 1, 2 & 3]. Organ injuries were graded using the OIS guidelines.5 Among the 95 splenic injuries, 52 had mild injuries (grade II), 37 had grade III [Fig. 4] and IV [Fig. 7] injuries [Fig. 1] and 6 had grade V injuries. Nineteen of the 43 patients with moderate to severe (grade III, IV and V) injuries required surgery. Sixty three patients had kidney injuries, 51 were unilateral and 12 bilateral. Of these 39 patients had grade III, 20 patients had grade IV and four patients Figure 4: Grade III splenic injury Figure 5: Grade II liver tear Figure 6: Retroperitoneal, (right) Paraspinal Haematoma. Note: the associated fracture involving the transverse process of L4 vertebra; it represents an ana- tomical entity at the level of aortic bifurcation 44 M A Z E N I H A M I D I , K H A L I D M A L D A O U D , I Z Z E D D I N Q TA I S H had grade V [Fig.2] injuries. Only fourteen of the 63 patients with renal injury up to grade IV required sur- gery. All patients with grade V injury were operated upon as expected. Forty eight patients had liver injuries. Twenty nine had grade II and III [Fig. 5], 15 had grade IV and 4 patients had grade V injuries. All grade V and 11 out of 15 grade IV liver injuries required surgery. The rest of the injuries were managed conservatively. Similarly, 13 patients had grade II and III pancreatic injuries. All these patients were managed conservatively. Of the total 245 patients in our study, 219 (89.4%) patients had solid organ injuries (liver, spleen, pan- creas or kidneys). CT OIS grading in these patients showed that all 62 patients with grade II injuries were conservatively managed, while 14 patients with grade V injuries were operated. However, the majority, i.e. 143 of these 219 patients, had either grade III or grade IV injuries and these were either managed conserva- tively or operated on depending on their assessment on an individual basis [Table 3]. Hence, in the overall analysis of solid organ injuries, OIS grading in isola- tion did not appear to predict the management proto- cols in a small proportion of them. After calculations, the sensitivity and specificity were 97% and 95%, re- spectively. In conjunction with close clinical monitoring, CT was reliable in the evaluation of blunt abdominal trau- ma in a selected group of patients, with overall sen- sitivity of 97% and specificity of about 95%. Positive predictive value was 82% and negative predictive value 100 %. Although sensitivity and specificity were calcu- lated regarding intra abdominal injury in our group of patients, showing an overall sensitivity of about 97% and specificity of about 95%, it should be mentioned that these results were less in cases of bowel, me- senteric or vascular injuries. For solid organ injuries the results were higher for specificity and the same for sensitivity. D I S C U S S I O N Several studies have highlighted the inaccuracies of the physical examination in BAT,6 however, CT requires a cooperative, haemodynamically stable pa- tient The accuracy of CT in haemodynamically stable blunt trauma patients has been well established. Sen- sitivity between 92% and 97.6% and specificity as high as 98.7% has been reported in patients subjected to emergency CT,7, 8 which is in the range of our study. Most authors recommend admission and observation following a negative CT scan.9, 10 In a recent study of 2,774 patients, the authors concluded that the nega- tive predictive value (99.63%) of CT was sufficiently high to permit safe discharge of BAT patients follow- ing a negative CT scan.11 We found good correlation between the CT quan- tification of the hemoperitoneum with the manage- ment approach. All 52 patients with small fluid were conservatively managed and similarly all 22 patients with large fluid required surgical exploration. Ap- proximately half of the patients with moderate fluid were explored. Taylor et al. also reported a similar experience.12 CT is notoriously inadequate for the diagnosis of mesenteric injuries and may also miss hollow visceral injuries. In patients at risk for mesenteric or hollow visceral injury, DPL is generally felt to be a more ap- propriate test.7, 13 A negative CT scan in such a patient cannot reliably exclude intra-abdominal injuries. CT has the unique ability to detect clinically unsuspected Figure 4: post operative finding, note grade IV splenic rupture Table 1: CT quantification of hemoperitoneum (Federle et al.)4 Description Estimates Approximate amount Fluid in only one space Small 100-200 ml Fluid in two or more spaces Moderate 250-500 ml Fluid in all spaces or pelvic fluid anterior/ superior to urinary bladder Large >500 ml Location of hemoperitoneum: 1. Perisplenic space 2. Perihepatic space 3. Morrison’s pouch 4. Left paracolic gutter 5. Cul-de-sac in pelvis. 45 TH E R O L E O F C O M P U T E D TO M O G R A P H Y I N B L U N T A B D O M I N A L TR AU M A injuries. In a series of 444 patients, in whom CT was per- formed to evaluate renal injuries, 525 concomitant abdominal and/or retroperitoneal injuries were diag- nosed. Another advantage of CT scanning over other diagnostic modalities is its ability to evaluate the ret- roperitoneal structures8 [Fig 6]. Kane performed CT in 44 haemodynamically stable blunt trauma patients following DPL. In 16 patients, CT revealed significant intra-abdominal or retroperitoneal injuries not diag- nosed by DPL. Moreover, the findings from CT result- ed in a modification to the original treatment plan in 58% of the patients.14 The OIS5, 15 (Organ Injury Scale) system is a rela- tively new system that is gaining recent acceptance in literature. Though its sole purpose is to establish uni- formity in different studies and thereby facilitate easy comparison, we found that splenic injury upto grade III infrequently required surgery. Only 5 out of 25 in this category required splenectomy as a part of sur- gery for multi-organ injury. On the contrary, grade IV or higher grade splenic injuries required surgery more often (11 out of 18 patients). We found no correlation between the grade of kid- ney injury with the management outcome. Although two cases of grade III kidney injuries required ne- phrectomies because of persistent hematuria and as- sociated multi-organ injuries respectively, it is quite possible that, in the absence of significant hematuria or multi-organ injuries, isolated renal injury up to and including grade IV can be conservatively managed. The overall likelihood of surgical management in- creases with higher OIS grading of solid organ injury, however OIS grading in isolation appears inadequate for predicting management protocol in the relatively small number of patients in our study. C O N C L U S I O N We conclude that the CT scan is accurate, safe and has all the attributes to make it an initial investigation of choice in haemodynamically stable patients with BAT. The rate of negative laparotomy is reduced by avoid- ing surgical intervention in cases that can be managed conservatively. R E F E R E N C E S 1. Wing V, Federle M, Morris J, et al. The clinical impact of CT for blunt abdominal trauma. Am J Roentgenol 1985; 145:1191-1194. 2. Udean J Abdominal Trauma, Blunt (Serial online). Avail- able from: http://www.emedicine.com/med/topic2804. htm. Accessed: 27 Feb 2003 3. Robert A Novelline, M, James T, et al. Helical CT in Emergency Radiology. Radiology 1999; 213:321-339. 4. Federle M, Jeffery R. Hemoperitoneum studied by com- puted tomography. Radiology 1983; 148:187-192. 5. Moore E, Cogbill T, Malagoni M, et al. Organ injury scaling. Surg Clin North Am 1995; 75:293-303. 6. Rodriguez A, DuPriest R, Shatney C. Recognition of intra-abdominal injury in blunt trauma victims. A pro- spective study comparing physical examination with peritoneal lavage. Am Surg 1982; 48:457-459 7. Peitzman A, Makaroun M, Slasky B, et al. Prospective study of computed tomography in initial management of blunt abdominal trauma. J Trauma 1986; 26:585-592. 8. Webster V. Abdominal trauma: Pre-operative assess- ment and postoperative problems in intensive care. Anaesth Intensive Care 1985; 13:258-262. 9. Lang E. Intra-abdominal and retroperitoneal organ in- juries diagnosed on dynamic computed tomograms ob- tained for assessment of renal trauma. J Trauma 1990; 30: 1161-1168. 10. Matsubara T, Fong H, Burns C. Computed tomography of abdomen (CTA) in management of blunt abdominal trauma. J Trauma 1990; 30:410-414. Table 3: CT-OIS grading and management in 219 patients with solid organ injuries. OIS grade Total number of patients Number of conservatively managed patients Number of operated patients II 62 62 0 III 96 85 11 IV 47 27 20 V 14 0 14 *Grade of the maximally injured organ in cases of multiorgan injuries. Table 2: CT quantification and management in 170 patients with Themoperitoneum on CT examination CT quantification of hemoperitoneum Total number of patients Number of conservatively managed patients Number of operated patients Small 52 52 0 Moderate 96 50 46 Large 22 0 22 46 M A Z E N I H A M I D I , K H A L I D M A L D A O U D , I Z Z E D D I N Q TA I S H 11. Livingston D, Lavery R, Passannante M, et al. Admis- sion or observation is not necessary after a negative abdominal computed tomographic scan in patients with suspected blunt abdominal trauma: Results of a prospective, multi-institutional trial. J Trauma 1998; 44: 272-282. 12. Taylor GA, Fallat ME, Potter BM, et al. The role of com- puted tomography in blunt abdominal trauma in chil- dren. J Trauma 1988; 28:1660-1664. 13. Nolan B, Gabram S, Schwartz R, et al. Mesenteric injury from blunt abdominal trauma. Am Surg 1995; 61:501- 506. 14. Kane N, Dorfman G, Cronan J. Efficacy of CT following peritoneal lavage in abdominal trauma. J Comp Assist Tomogr 1987; 11:998-1002 15. Moore EE, Cogbill TH, Jurkovich GJ, Shackford SR, Marangoni MA, Champion HR. Organ injury scaling: spleen and liver (1994 revision). J Trauma 1995; 38:323– 324.