Author, date and country | Patient group | Study type (level of evidence) | Outcomes | Key results | Study Weaknesses |
---|---|---|---|---|---|
Nishijima DK, et al. 2012 USA | 12 studies included for analysis. Total patient group of 10,757. Inclusion criteria; adult patients with any blunt abdominal trauma except for 2 studies which included only adult patients in motor vehicle collisions | Systematic Review | The presence or absence of abdominal tenderness does not include or exclude intra-abdominal injury. Rebound tenderness, abdominal distention, guarding, seat belt sign, and hypotension (systolic blood pressure <90 mm Hg) have likelihood ratios indicating the need for evaluation. | Lack of physician’s clinical impression regarding the risk of IAI. Different inclusion/exclusion criteria used in each study. Old studies from more than 10 years ago. | |
Seat Belt Sign | Sensitivity, % (95% CI) = 50 (35-65) Specificity, % (95% CI) = 91-95 Positive Likelihood Ratio (95% CI) = 5.6-9.9 Negative Likelihood Ratio (95% CI) = 0.53-0.55 | ||||
Rebound Tenderness | Sensitivity, % (95% CI) = 5 (0-10) Specificity, % (95% CI) = 99 (99-100) Positive Likelihood Ratio (95% CI) = 6.5 (1.8-24) Negative Likelihood Ratio (95% CI) = 0.96 (0.91-1.0) | ||||
Abdominal Distention | Sensitivity, % (95% CI) = 13 (6-20) Specificity, % (95% CI) = 97 (95-98) Positive Likelihood Ratio (95% CI) = 3.8 (1.9-7.6) Negative Likelihood Ratio (95% CI) = 0.90 (0.83-0.98) | ||||
Guarding | Sensitivity, % (95% CI) = 26 (16-35) Specificity, % (95% CI) = 93 (91-95) Positive Likelihood Ratio (95% CI) = 3.7 (2.3-5.9) Negative Likelihood Ratio (95% CI) = 0.80 (0.70-0.91) | ||||
Abdominal pain as a symptom | Sensitivity, % (95% CI) = 70 (57-81) Specificity, % (95% CI) = 57 (51-63) Positive Likelihood Ratio (95% CI) = 1.6 (1.3-2.0) Negative Likelihood Ratio (95% CI) = 0.52 (0.34-0.79) | ||||
Abdominal tenderness to palpation | Sensitivity, % (95% CI) = 71 (57-82) Specificity, % (95% CI) = 50 (44-57) Positive Likelihood Ratio (95% CI) = 1.4 (1.3-1.5) Negative Likelihood Ratio (95% CI) = 0.61 (0.46-0.80) | ||||
Beviss-Challinor K, et al. 2020 South Africa | 139 patients who had undergone blunt trauma from 01 January 2018 - 31 March 2018 and had a CT scan. The clinical details on the request for the scan and the interpretation of the scan were compared. | Retrospective Study | Percentage of patients with a sign of intra-abdominal injury on CT following: | The retrospective design meant that parameters were not specified in every case, thereby preventing determination of their diagnostic sensitivities and specificities. Only a univariate analysis was conducted so confounding variables were not controlled. The capture of data pertaining to imaging tests performed prior to CT was limited which made determining how the diagnosis was made difficult. | |
Positive abdominal examination | 35%, p=0.05 | ||||
Negative abdominal examination | 0% p=0.05 | ||||
Neeki M, et al. 2017 USA | 594 patients brought to the ED following blunt trauma and assessed for abdominal pain on examination, then findings correlated with CT | Retrospective Study | Abdominal tenderness on physical examination | 214 | Due to its retrospective nature, this study was dependent on the varying documentation of the providers’ documentation and clinical acumen. Further, variation in provider documentation may also have impacted the identification and exclusion of patients with distracting injuries. Only abdominal tenderness was assessed, not other objective abdominal. Interpretation of the results are limited to the context of abdominal tenderness findings in correlation with CT imaging. The exclusion of patients with BAT who did not receive an abdominal or pelvic CT may have resulted in the missed inclusion of relevant cases. |
Positive CT findings from patients with abdominal tenderness on physical examination | 78 (36.5%), p=<0.001 | ||||
Shreffler J, et al. 2020 USA | 425 patients presenting to ED with an abdominal seatbelt sign. Compared to CT findings of intra-abdominal injury. | Retrospective Study | Percentage of positive CT findings from patients with the following findings on abdominal examination: | Shreffler J, et al. 2020 USA 425 patients presenting to ED with an abdominal seatbelt sign. Compared to CT findings of intra-abdominal injury. Retrospective study Percentage of positive CT findings from patients with the following findings on abdominal examination: Many charts documented “seat belt sign” without further description. Any cases with uncertain type of seat belt sign were analysed as ‘unknown’, excluded from the abrasion/ecchymosis cohort analysis. Due to retrospective design and potential for missed subjects, an IAI rate of 36.1% may not predict the incidence of IAI in other populations. The ED cares for trauma patients in urban and rural areas with significant mechanism of trauma, thus, patients have a high probability of abdominal injuries. The study may have missed patients who presented to outlying facilities on return visits and were not transferred to the trauma centre for care. | |
Abrasion | 45.4% p=<0.05 | ||||
Ecchymosis | 32.8% p=<0.05 | ||||
Abrasion and ecchymosis | 37.1% p=<0.05 | ||||
Overall positive CT findings from a positive abdominal examination | 53.6% p=<0.05 | ||||
Incidence of intra-abdominal injury (IAI) in the above sample group | 36.1% p=<0.05 | ||||
Klempka A, et al. 2021 Germany | 30 patients presenting with blunt trauma who underwent CT scan following signs of superficial injury to the abdomen | Retrospective Study | Correlation between superficial injury of the abdominal cavity and an internal injury | Very small sample size Retrospective observation of the superficial lesions on CT scans was not correlated with a clinical examination. The data were obtained only from one centre. Thus, the results should be confirmed by multi-centre studies on larger populations. | |
Whole body CT | Superficial injury (n=30) p=0.117 | ||||
Internal injury of abdomen | n = 11 %36.7 | ||||
No internal injury of abdomen | n = 19 %63.3 | ||||
Shojaee M, et al. 2014 Iran | 261 patients who presented to ED following blunt trauma. Assessed for abdominal injury and then the findings compared to CT which was considered the gold standard. | Prospective Observational Study | CT identified 48 patients with IAI. The following signs were present at examination of the patient group. | The age range which mostly covers 21-30 years old misrepresents other age groups especially older adults and children. Investigators were not blinded to the purpose of this study. | |
Shojaee M, et al. 2014 Iran | 261 patients who presented to ED following blunt trauma. Assessed for abdominal injury and then the findings compared to CT which was considered the gold standard. | Prospective Observational Study | CT identified 48 patients with IAI. The following signs were present at examination of the patient group. | The small assessed population is a potential limitation of the present study. A higher sample size may change other indices into statistically significant factors related to IAI diagnosis. The age range which mostly covers 21-30 years old misrepresents other age groups especially older adults and children. Investigators were not blinded to the purpose of this study. | |
Abdominal pain | Percentage of patients = 62.5% Odds ratio = 5.4 Logistic regression = beta = 1.6 p = 0.05 | ||||
Abdominal guarding | Percentage of patients = 10.4% Odds ratio = 6.1 Logistic regression = beta = 0.5 p = 0.8 | ||||
Abdominal tnederness | Percentage of patients = 75% Odds ratio = 10.0 Logistic regression = beta = 2.9 p = 0.008 | ||||
Abdominal wall sign | Percentage of patients = 35.4% Odds ratio = 2.0 Logistic regression = beta = 0.2 p = 0.6 | ||||
Hekimoglu A, et al. 2019 Turkey | A total of 535 adult abdominal trauma patients: 359 males, 176 females, who underwent CT examination after positive physical examination | Retrospective Study | The ability of pain on abdominal palpation to predict presence of positive abdominal signs on CT | Limitations of a retrospective study Abdominal examination was limited to palpation only, and no other injuries were included. | |
Sensitivity | 59% | ||||
Specificity | 87% | ||||
Positive Estimated Value | 70% | ||||
Negative Estimated Value | 81% | ||||
Lee JY, et al. 2017 South Korea | 786 patients that were admitted to ED following blunt trauma. The study used their result to create a set of criteria for the requirement for CT. | Retrospective Study | Results of multivariate analyses of the need for abdominal and pelvic computed tomography | Pain is a very subjective scoring system so there is significant variation between patients. There are limitations of a retrospective, single centre study. | |
Laceration in torso region | Odds ratio (95% confidence interval) = 1.036 (0.432–2.484) P value = 0.937 | ||||
Pain | |||||
Unevaluable | Odds ratio (95% confidence interval) = 1.645 (0.294–9.210) P value = 0.571 | ||||
Positive | Odds ratio (95% confidence interval) = 3.391 (2.135–5.386) P value = <0.001 | ||||
Peritoneal Signs | |||||
Unevaluable | Odds ratio (95% confidence interval) = 1.284 (0.227–7.274) P value = 0.778 | ||||
Positive | Odds ratio (95% confidence interval) = 7.351 (1.449–37.287) P value = 0.016 | ||||
Richards JR, Derlet RW. 1997 USA | 444 patients evaluated by CT for the presence of intra-abdominal injury, based on multiple factors including physical examination | Retrospective Study | Ability of abdominal tenderness to screen for IAI. | Limitations of a retrospective review A selection bias existed in that ICU admissions and patients going directly to the operating room were omitted. The presence of abdominal tenderness was subjective, and the location, presence of rebound, guarding, or distention was not characterised. | |
Sensitivity | 63% (95% CI 48-77%) | ||||
Specificity | 65% (95% CI 60-70%) | ||||
Positive Predictive Value | 19% (95% CI 13-25%) | ||||
Negative Predictive Value | 93% (95% CI 90-96%) | ||||
Jones EL, et al. 2014 USA | 285 patients identified from the Trauma Registry that were assessed in the ED for the length of time it took for signs of blunt abdominal trauma to appear. Presence of injury was then confirmed by CT | Retrospective Study | Patients who displayed positive abdominal signs confirmed by CT | 82% | The retrospective identification of specific clinical variables prompting the imaging or intervention is prone to error. In addition, the hierarchy of clinical signs and symptoms was designed for ease of categorization based on the authors' experience but may not be applicable in all situations. |
Grieshop NA, et al. 1995 USA | The records of 1096 patients that attended a Level 1 trauma centre following blunt trauma were reviewed for findings on initial physical examination, and results of CT, DPL, laparotomy and postmortem. | Retrospective Study | Percentage of patients with an abnormal abdominal examination that were found to have significant IAI | 17.8% | Retrospective design means that correlation does not equal causation. This was only carried out at a single centre so the results may not be generalisable. |
The ability of an abnormal abdominal examination to predict IAI | Odds ratio = 10.3 p = 0.0001 | ||||
Jost E, et al. 2017 Canada | 39 patients from the Southern Alberta Trauma Registry who had a CT for blunt abdominal trauma | Cross-sectional Study | Association of categorically measured physical findings with likelihood of hollow viscus injury at presentation | Imaging alone even with modern technologies cannot reliably predict hollow viscus injury A corresponding limitation is that the confidence intervals for the positive likelihood ratios for abdominal distention crossed unity, likely due to the small sample size of the study Another limitation is that the statistical methods do not suggest specific numerical values which increase the suspicion of hollow vicus injury. The aim of this study was not to confirm values that others had suggested, but rather to identify which imaging, physical, and laboratory findings were diagnostically accurate | |
Peritonitis | Number with therapeutic odds ratio = 6 Positive likelihood ratio = approaches infinity Sensitivity = 37.5% (15.2–64.6) Specificity = 100% (85.2–100) | ||||
Seatbelt Sign | Number with therapeutic odds ratio = 4 Positive likelihood ratio = approaches infinity Sensitivity = 25% (7.27–52.4) Specificity = 100% (85.2–100) | ||||
Abdominal Distention | Number with therapeutic odds ratio = 6 Positive likelihood ratio = 1.73 (0.634–4.69) Sensitivity = 37.5% (15.2–64.6) Specificity = 78.3% (56.3–92.5) | ||||
Farrath S, et al. 2013 Brazil | 331 blunt trauma patients who were admitted to the ED and had a CT or laparotomy. | Retrospective Study | Comparison of qualitative variables between groups A (severe abdominal injury AIS >= 3) and B (abdominal injury AIS <3) as displayed on CT: univariate analysis. Data presented as percentage related to the presence of the variable in a particular group. | Patients with distracting injuries and lower GCS were included in the study The sample group was 80% male so the results may not be applicable to females. | |
Altered Abdominal Examination | Group A n = 101 61.4% Group B n = 230 28.7% p <0.001 | ||||
Richards JR, Derlet RW. 1998 USA | 196 patients receiving a CT in the ED of a Level 1 trauma centre following blunt trauma | Prospective Study | Comparison of patients with and without IAI confirmed by CT | Some of the variables requested on the original questionnaire required subjective evaluation from the examining physician, including the chest and abdominal examination, reason for obtaining the scan, and planned disposition. In addition, there were different levels of training of the examining physicians, from intern to attending. The definition of IAI included any abnormality likely caused by trauma. There were many nonoperative conditions identified, such as renal contusion. | |
Abdominal Tenderness | Without IAI (n = 174) 102 With IAI (n = 22) 18 p = 0.04 Odds ratio (95% CI) 3.2 (1.0,9.8) | ||||
As a screen for intra-abdominal injury, confirmed by CT, abdominal examination was: | |||||
Sensitivity | 82% (95% CI 60-95%) | ||||
Specificity | 41% (34-49%) | ||||
Positive Predictive Value | 15% (9-23%) | ||||
Negative Predictive Value | 95% (87-99%) | ||||
Deunk J, et al. 2010 Netherlands | 1040 patients admitted to a Level 1 ED who met the high-energy trauma protocol. | Observational Prospective Study | Crude OR With 95% CI for >1 Traumatic Injury on Abdominal CT, Using Univariate Logistic Regression Analysis | Although CT is a very sensitive modality to detect abdominal injuries, it is known to be less than 100% sensitive. In this study, CT was false-negative in 0.9% of the patients, mostly consisting of hollow-visceral and pancreatic injuries. The data in this study were derived from a blunt trauma population in a single Llevel 1 trauma centre. The data does not necessarily reflect other less injured populations. | |
Abnormal examination of the abdomen and/or pelvis | n = 248 OR = 3.60 CI = 2.67–4.86 | ||||
Livingston DH, et al. 1998 USA | 2744 patients admitted to one of four Level 1 trauma centres following blunt trauma. Patients underwent serial abdominal examination and CT to assess injuries. | Prospective study | Percentage of patients with physical abdominal findings of bruising, tenderness or guarding | 61% | Possible variation in documentation between hospitals and variation in practice. |
Percentage of patients with positive abdominal findings that had an abnormal CT scan | 26% | ||||
Ferrera PC, et al. 1998 USA | 350 patients admitted to a Level 1 ED following blunt trauma. Split into two groups depending on the presence or absence of abdominal pain and correlated with findings on CT. | Prospective study | The values of abdominal pain or tenderness to predict a positive finding of IAI on CT | The study is limited in that patients either discharged from the ED or admitted to the hospital without receiving abdominal CT or DPL may have had missed IAI. There was no outpatient follow-up on these patients and it is possible that they were seen at other hospitals presenting with symptoms referrable to delayed diagnosis of IAI (eg. splenic ruptures or bowel perforations). | |
Sensitivity | 82% (95% confidence interval [CI], 78% to 86%) | ||||
Specificity | 45% | ||||
Positive Predictive Value | 21% | ||||
Negative Predictive Value | 93% (95% CI, 90% to 96%) | ||||
Shannon L, et al 2015 UK | 588 multi-trauma patients were enrolled. Their CT request cards were used to discover the clinical suspicion of injury and then compared to the CT reports | Prospective study | Percentage of patients with suspicion of intra-abdominal injury on the CT request card which had IAI on CT | 31% | Inability to analyse the initial findings that led the physician to suspect whether a body area was injured and how this compared to CT findings, there is limited data to indicate whether the suspicion was based on clinical findings, mechanism, or a combination. |
Klempka A, et al. 2020 Germany | 250 patients following blunt trauma, who were assessed in ED, need for CT identified and findings reviewed to see if matched assessment | Retrospective study | Correlation between superficial injury of the abdominal cavity and an internal injury | The assumption that all body areas would be accessible for clinical examination to the same extent as for cross-sectional imaging in polytraumatic patients. The retrospective observation of the superficial lesions on CT scans was not correlated with a clinical examination. Data was obtained only from one university hospital centre. Thus, observations should be confirmed by multi-centre studies on larger populations. | |
Internal injury of the abdomen | n=11 %=36.7 | ||||
No internal injury of the abdomen | n=19 %=63.3 | ||||
Barmparas G, et al 2018 USA | 196 patients admitted following blunt trauma with an abdominal seatbelt sign to a Level 1 trauma centre, whose work up and CT results were examined | Retrospective study | Percentage of patients who had an abdominal seatbelt sign with a positive finding on CT n = 183 | 37.7% | Findings should be interpreted with caution given the retrospective nature of this work and the potential associated bias. There is a possibility that patients with an abdominal seat belt sign might not have been captured. Similarly, it is possible that the presence of a seatbelt sign was not documented in the chart. Findings might not apply to pregnant patients. In addition, seven patients did not undergo a CT in violation of the institutional protocol and although they did not re-present in a delayed fashion, the possibility of them presenting to another institution cannot be excluded. |
Benjamin E, et al. 2018 USA | 1193 blunt trauma patients admitted to a Level 1 trauma centre who had a CT within 24 hours, results were then compared to the work up characteristics | Prospective study | The presence of positive abdominal examination compared to CT findings | Once discharged, the majority of patients had limited follow-up and delayed presentation of injuries may have been missed. Although abdominal imaging is obtained liberally as an institutional practice, there was no algorithm guiding the decision of which patients underwent cross-sectional imaging. This potentially inflates the denominator of negative studies and leaves a potentially unstudied population of patients that may have had missed injury but were never imaged. | |
Abdominal pain | Percentage of study group: 21.2% (253 patients) Percentage with positive CT findings 22.1% (56 patients) | ||||
External signs of trauma | Percentage of study group: 38.0% (453 patients) Percentage with positive CT findings 23.0% (104 patients) | ||||
Poletti PA, et al. 2004 USA | 714 patients admitted to a Level one trauma centre, where CT was ordered based on clinical and laboratory results | Prospective study | Multivariate analysis of abdominal examination to predict an IAI as defined by CT results | Only patients already selected to undergo CT were enrolled. The decision not to perform CT in a certain number of patients was made on the basis of criteria that could not be analysed. However, because most of the patients with suspicion of blunt abdominal trauma undergo abdominal CT, this limitation only concerns a very small number of cases and will not contribute any consistent bias to the results. Not all patients had data forms completed may have led to an unmeasured selection bias. A substantial amount of data was not available on the patient notes. | |
Guarding | Level (%) = 9 Sensitivity (%)= 26 PPV (%) =32 Specificity (%) = 93 NPV (%) = 91 | ||||
Tenderness | Level (%) = 33 Sensitivity (%)= 46 PPV (%) =16 Specificity (%) = 69 NPV (%) = 91 | ||||
Rebound tenderness | Level (%) = 1 Sensitivity (%)= 5 PPV (%) =44 Specificity (%) = 99 NPV (%) = 89 | ||||
Distention | Level (%) = 5 Sensitivity (%)= 13 PPV (%) =34 Specificity (%) = 97 NPV (%) = 89 | ||||
GCS, guarding and tenderness | Level (%) = 48 Sensitivity (%)= 68 PPV (%) =17 Specificity (%) = 55 NPV (%) = 93 | ||||
Mackersie RC, et al. 1989 USA | The records of 3223 major trauma patients admitted to the ED who sustained blunt injury were reviewed. For each patient, the presence or absence of a significant intra-abdominal injury (defined as an injury for which operative repair was required) was tabulated. | Prospective observational study | Correlation between abdominal examination and intra-abdominal injury n = 1648 | The study didn’t specifically analyse the factors of a positive abdominal examination and was more focussed on risk factors for blunt trauma associated abdominal injury. | |
Abdominal Tenderness | 35% | ||||
Abdominal Distention | 0.4% | ||||
Smith CB, et al. 2011 USA | Convenience sample of 400 trauma patients that were assessed by 18 emergency medicine physicians who completed a data sheet for expected injuries on CT | Prospective study | Diagnostic positive abdominal examination for emergency physician bedside assessment compared with CT as the gold standard for the presence or absence of clinically significant injury | Convenience sampling could have led to selection bias in including sicker patients, as these are the ones physicians might have been most likely to remember to include in the study. This seems probable given the high number of intubated patients, with almost half intubated prehospital or immediately in the ED. The trauma department requests whole-body CT on all Level 1 patients with blunt trauma, with very few exceptions. This practice policy often leads to body regions that are scanned despite little initial clinical concern for injury instead of admitting to the hospital for serial examinations and close observation. Because the study evaluated 1 group of attending emergency medicine physicians, it is possible that other physician groups could have dissimilar prediction ability. Because this was an unstructured rating system, there may also be considerable heterogeneity among physicians as to what they considered “very low,” “low,” “intermediate,” and so on. | |
Positive if pretest rating is: high | Prevalence (95% CI) =29.2 (24.4-34.5) % Sensitivity (95% CI) =18.8 (14.8-23.5) % Specificity (95% CI) =74.3 (69.2-78.9) % NPV (95% CI) =74.3 (69.2-78.9) % PPV (95% CI) =72.0 (66.8-76.7) | ||||
Positive if pretest rating is: intermediate | % Sensitivity (95% CI) =80.6 (75.8-84.6) % Specificity (95% CI) =80.6 (75.8-84.6) % NPV (95% CI) = 80.6 (75.8-84.6) % PPV (95% CI) = 58.5 (53.0-63.9) | ||||
Positive if pretest rating is: low | % Sensitivity (95% CI) =84.4 (79.9-88.0) % Specificity (95% CI) =50.6 (45.1-56.2) % NPV (95% CI) = 88.7 (84.7-91.8) % PPV (95% CI) = 41.3 (36.0-46.9) | ||||
Positive if pretest rating is: very low | % Sensitivity (95% CI) =97.9 (95.5-99.1) % Specificity (95% CI) =16.3 (12.6-20.9) % NPV (95% CI) = 95.0 (91.9-97.0) % PPV (95% CI) = 32.5 (27.5-37.9) | ||||
Beck D, et al. 2004 USA | 213 patients who presented to a Level I trauma centre as a trauma team alert and underwent an abdominal CT scan. The trauma team leader filled out a data sheet before the CT scan documenting the indications for CT | Prospective Study | Indications for CT | Only small sample sizes used which limits generalisability | |
Abnormal abdomen exam (tender/ distended) | Positive CT (n = 56) = 25 (45%) Negative CT (N = 157) = 73 (46%) p-Value =0.81 | ||||
Visible abdomen/ pelvis trauma | Positive CT (n = 56) = 7 (12%) Negative CT (N = 157) = 14 (9%) p-Value =0.44 |