Towards evidence based emergency medicine: best BETs from the Manchester Royal Infirmary. Detection of pneumoperitoneum on erect chest radiograph

A short cut review was carried out to establish whether a normal erect chest radiograph excludes the diagnosis of perforated abdominal viscus. Altogether 37 papers were found using the reported search, of which two presented the best evidence to answer the clinical question. The author, date and country of publication, patient group studied, study type, relevant outcomes, results and study weaknesses of these best papers are shown in table 1. A clinical bottom line is stated.

[Traumatic jejunal entrapment in a patient with Bechterew disease]

We report an unusual case of incarceration of small bowel between the 4th and 5th lumbar vertebrae in a patient with rheumatoid spondylitis. Incarceration of the loop of jejunum within the fracture or between dislocated lumbar vertebrae is an uncommon entity. The cases of traumatic jejunal entrapment have been previously reported in the literature [1, 2, 3, 4, 5, 6, 7, 8, 9, 11]: 2 cases occurred in adults and 8 in children. There has been no report on this injury in patients with rheumatoid spondylitis (Bechterew arthritis).

Management of colonic perforation during percutaneous nephrolithotomy in horseshoe kidney

Few cases of colonic injury during percutaneous nephrolithotomy (PCNL) have been reported in orthotopic kidneys and none in horseshoe kidney, and the management protocol has not been standardized. A plain film on postoperative day 1 following PCNL showed contrast medium in the descending colon, leading to the diagnosis of colonic injury in a 53-year-old male patient with horseshoe kidney and multiple bilateral stones. He was asymptomatic and was treated successfully by minimally invasive techniques. An asymptomatic patient with a colonic injury following PCNL can be treated by minimal manipulations. Computed tomography imaging is necessary prior to percutaneous surgery on a horseshoe kidney.

Diagnostic accuracy of focused appendiceal CT in clinically equivocal cases of acute appendicitis

PURPOSE

To determine the diagnostic accuracy of modified focused appendiceal computed tomography (CT) to exclude or confirm appendicitis in patients who presented with equivocal symptoms and signs of appendicitis.

MATERIALS AND METHODS

One hundred patients (age range, 14-81 years; mean age, 30.6 years) with equivocal symptoms and signs of acute appendicitis were included in this prospective study. Patients were given 30 mL of diatrizoate meglumine and diatrizoate sodium and 60 mL of sorbitol mixed in 1 L of water orally over 1 hour. CT was performed 1.5 hours after the commencement of oral contrast material administration. The criteria used for the diagnosis of appendicitis were (a) appendix greater than 6 mm in maximum diameter, (b) no contrast material in the appendiceal lumen, and (c) inflammatory changes in the periappendiceal fat. CT results were compared with histopathologic findings at appendectomy. Patients with negative CT findings were followed up by telephone or clinically.

RESULTS

Of 100 cases, 30 were positive at CT and 70 were negative. There were 28 true-positive cases; two false-positive cases, one cecal diverticulitis and one pelvic peritonitis with periappendicitis; and two false-negative cases, one perforated appendix and one mucosal and submucosal inflammation of the appendix but no transmural inflammation. Sensitivity was 93%, specificity was 97%, and accuracy was 96%.

CONCLUSION

Focused appendiceal CT in which oral contrast material is used alone yields high levels of accuracy in clinically equivocal cases of acute appendicitis.

Influence of preoperative computed tomography on patients undergoing appendectomy

The frequency of computed tomography (CT) ordered by emergency department physicians at our facility was noted to sharply increase in early 1998 after a New England Journal of Medicine (NEJM) article recommending routine CT in patients with suspected appendicitis. Numerous studies have proven the accuracy of CT for detecting acute appendicitis; however, the most appropriate use of CT continues to evolve. We sought to evaluate the effect of increased CT use on negative appendectomy rate and perforation rate at our institution and to better delineate in whom CT is most beneficial. CT use was retrospectively evaluated and found to sharply increase in April 1998. The authors then reviewed the medical records of 291 consecutive patients undergoing appendectomy 18 months before and after the NEJM article. Patients with interval appendectomies and those 12 years of age or younger were excluded. The remaining 226 patients constitute the study cohort. The study cohort was then divided into the two groups. The "Discriminate Group" consists of patients from the 18 months before the NEJM article impact and a period of selective CT use. The "Indiscriminate Group" comprises patients from the subsequent 18 months in which CT use was substantially higher and routinely obtained before surgical evaluation. After chart review an objective clinical score (Alvarado score) was assigned to each patient. Comparison was then made between the two groups on perforation rate, negative appendectomy rate, time delay to operating room, and Alvarado score. Additionally patients undergoing preoperative CT were compared with those without CT. These groups were also evaluated on the basis of negative appendectomy rate, perforation rate, and delay to the operating room. CT in patients with abdominal symptoms associated with appendicitis increased from 188 in the Discriminate Group to 1035 in the Indiscriminate Group. In the Discriminate Group the negative appendectomy rate was 15.1 per cent. After the indiscriminate use of CT the negative appendectomy rate decreased to 13.3 per cent, but this was not significant. Males experienced a decrease in the negative appendectomy rate from 10.1 to 6.9 per cent, whereas the rate for females increased slightly from 21.3 to 22.9 per cent. Again we found no statistical significance in these changes. The overall perforation rate of 17.9 per cent in the first 18 months decreased to 13.3 per cent in the following 18 months but again was not statistically significant. The Alvarado scores between the Discriminate and Indiscriminate groups were 6.7 and 7.3, respectively (P = 0.02). Patients with preoperative CT averaged 11.9 hours to the operating room compared with 6.5 hours for those without CT (P = 0.03). Use of CT did not decrease perforation rate but did globally reduce negative exploration (P = 0.05). This reduction in negative exploration however was not discriminated by sex. CT use in suspected acute appendicitis has greatly increased over the past several years. The dramatic increase in CT use at our institution has not resulted in dramatic decreases in negative appendectomy rate or statistically significant changes in perforation rate. The optimal use of CT in evaluating patients with suspected appendicitis has yet to be determined. Surgical consultation should be obtained early to avoid indiscriminate tests.

Pediatric appendicitis in "real-time": the value of sonography in diagnosis and treatment

OBJECTIVES

To determine the accuracy of sonography in the diagnosis of clinically equivocal appendicitis, and to identify the factors leading to an inaccurate ultrasound diagnosis. The impact of sonographic findings on clinical management and outcome of children with appendicitis is examined.

METHODS

We performed a retrospective review of 317 children who attended the emergency department (ED) of a children's hospital for acute abdominal pain for which acute appendicitis was the main differential diagnosis. They had ultrasound because the diagnosis was uncertain clinically.

RESULTS

The positive predictive value of ultrasound for appendicitis was 0.92, and the negative predictive value was 0.88. The sensitivity and specificity could not be determined because there were 43 patients with equivocal ultrasound results. The pitfalls hindering the accuracy of ultrasound diagnosis included a high incidence of perforated appendicitis at presentation, the retrocecal appendix, and other technical factors such as abdominal guarding, excessive bowel gas, obesity, inadequate bladder filling, and the uncooperative patient. When ultrasound findings were combined with clinical judgment in clinical management, there were only five cases of non-therapeutic laparotomy and eight cases of delayed surgery due to missed diagnosis in our cohort.

CONCLUSIONS

Ultrasound is a useful for the evaluation of acute abdominal pain in children. However, in the setting of a pediatric hospital ED, the accuracy of ultrasound and its ability to improve early hospital triage may be reduced. Repeated clinical review is still essential and in selected cases, appendiceal CT scan may be required to guide therapeutic decision making.

Sonography in acute appendicitis: diagnostic utility and influence upon management and outcome

A study is made of the diagnostic utility of echography in clinically suspected appendicitis, and its influence upon patient management and outcome. A total of 374 consecutive patients with possible appendicitis were prospectively evaluated by ultrasound. Two groups were established: group A (high clinical probability, > or =0.70) and group B (moderate clinical probability, 0.20-0.60). In group-A patients (n = 105, 28%), prevalence of appendicitis = 0.90) underwent surgery regardless of the echographic findings. In group B (n = 269, 72%), prevalence of appendicitis = 0.28) surgery was performed in the event of positive echography, whereas negative echographic findings did not definitively discard appendicitis. The diagnostic utility of echography was evaluated by applying the Pauker-Kasirer threshold approach to clinical decision making. The influence of ultrasound upon outcome was in turn evaluated by contrasting the total appendectomized patients (190 of 374) with a series of 181 individuals subjected to appendectomy prior to the introduction of echography. The probability of appendicitis in the presence of positive echography was 0.95 in group A (sensitivity = 0.92) and 0.89 in group B (sensitivity = 0.91). The probability of appendicitis in the event of negative ultrasound was 0.58 in group A (specificity = 0.55) and 0.03 in group B (specificity = 0.95) . In 46% of cases the echographic findings led to a change in therapeutic regimen. In addition, the incidence of negative appendectomies was significantly reduced (19.3 vs 11.6% with echography; p = 0.03), as was the delay in establishing a diagnosis (under 6 h in 68.5 vs 84.2% with echography; p = 0.002) and the number of medical acts required (three in 71.3 vs 84.1% with echography; p = 0.001). There was no significant reduction in the incidence of perforated appendicitis (17.1 vs 17.9% with echography), in the number of postoperative complications (13.8 vs 7.6% with echography), or in the days of hospital stay (4.44 vs 4.80 with echography). Echography proved useful in group B, and was generally of little utility in group A. The technique had a positive influence on treatment, with management reorientation in a considerable number of patients, and on outcome, since ultrasound contributed to establishing an earlier diagnosis, with a reduction of unnecessary appendectomies.

The role of oral contrast administration immediately prior to the computed tomographic evaluation of the blunt trauma victim

BACKGROUND

It is unclear whether the administration of oral contrast followed by immediate computerised tomographic (CT) scanning presents a significant risk of aspiration and whether it is useful in the diagnosis of hollow viscus injury.

OBJECTIVE

Determine the number of intestinal perforations diagnosed by oral contrast enhanced CT scans for blunt trauma and identify those who developed aspiration pneumonitis causally related to oral contrast administration.

METHODS

We analysed a database of consecutive blunt trauma admissions over a 2-year period. The majority received oral contrast immediately prior to CT scanning. We determined the number of intestinal perforations identified by abdominal CT confirmed at laparatomy and the number of cases of aspiration pneumonia.

RESULTS

Nine (1%) of the 1173 CT scans identified enteric perforations. Oral contrast enhanced CT scans demonstrated pneumoperitoneum (3), extraluminal contrast extravasation (2), and the presence of free fluid with small bowel wall thickening (8). In this same cohort, eight (0.7%) cases of aspiration pneumonia were diagnosed within 48 h of admission in patients with a mean GCS of 4.25; only one (0.1%) was temporally related to oral contrast administration. In a prospective study, none of the 65 consecutive patients who received oral contrast had witnessed aspiration.

CONCLUSIONS

Oral contrast administration given immediately prior to CT scanning does not increase the risk of clinically significant aspiration and assists in the detection of enteric perforation.

Effect of cross-sectional imaging on negative appendectomy and perforation rates in children

PURPOSE

To compare negative appendectomy and perforation rates in children who underwent ultrasonography (US), computed tomography (CT), or no imaging before urgent appendectomy.

MATERIALS AND METHODS

All children who underwent urgent appendectomy during a 4(1/2)-year period were identified in a surgical billing database. Pathology reports were coded as negative or as showing acute inflammation or perforation. Imaging up to 14 days before appendectomy or abscess drainage was noted, and imaging-based diagnoses were compared with pathologic findings. Patient age and sex were recorded.

RESULTS

Two hundred ninety-nine children, 176 (59%) male and 123 (41%) female (mean age, 10.4 years; age range, 1--21 years), underwent urgent appendectomy. One hundred twenty-six (42%) underwent no imaging, 121 (41%) underwent US with or without CT, and 52 (17%) underwent CT only; 44 (15%) underwent both US and CT. There were significantly higher rates of appendectomy with normal pathologic findings ("negative appendectomy") in patients who underwent no imaging (14% [18 of 126]) or US (17% [20 of 121]) versus the rates in those who underwent CT only (2% [one of 52]) (P =.02 and P =.007, respectively). The negative appendectomy rate was 7% in 96 patients who underwent CT with or without prior US. The perforation rates were not significantly different.

CONCLUSION

As compared with children who underwent no preoperative imaging and those who underwent US, children who underwent CT had a significantly lower negative appendectomy rate, without a significantly higher perforation rate.

Perforated Amyand's hernia

We report a case of acute perforated appendicitis in an incarcerated inguinal hernia, termed an Amyand's hernia. Although perforated appendicitis within an incarcerated inguinal hernia is uncommon, with a published incidence of 0.13%, its clinical presentation varies considerably, depending on the extent of periappendicular inflammation and the presence or absence of peritoneal contamination.

Penetration of the duodenum by an ingested needle with migration to the pancreas: report of a case

A case of a penetration of the duodenum by a needle with migration to the pancreas in a 50-year-old man is reported herein. The patient was referred to us with a chief complaint of diarrhea. An abdominal plain roentgenogram showed a needle in the upper abdominal area. An abdominal computed tomography scan and contrast X-ray revealed the foreign body to be located outside of the duodenum and in the head of the pancreas. An emergency operation was therefore performed on the first day and the needle in the head of the pancreas was thus extirpated safely. A perforation of the gastrointestinal tract by an ingested foreign body is difficult to accurately and quickly diagnose when no peritonitis or abscess formation is observed. Therefore, the use of contrast X-ray is considered to be useful in the diagnosis of such a perforation.

Analysis of bowel perforation in necrotizing enterocolitis

The most severe complication of necrotizing enterocolitis (NEC) is bowel perforation. Identification of neonates at high risk for perforation and optimization of radiologic imaging to identify bowel perforation are necessary to reduce the high mortality rate associated with this catastrophic event. One hundred and fifty-five cases of NEC were seen at our institution during a 5.5-year period. Nineteen (12%) progressed to perforation. A review of surgical findings, autopsy results and radiographs from these patients shows only 63% had radiographic evidence of free air in the peritoneal cavity at the time of perforation. Twenty-one percent had radiographic evidence of ascites but no pneumoperitoneum, and 16% had neither free air nor ascites. Thus purely radiographic criteria for bowel perforation in NEC are imprecise, and paracentesis is mandatory in NEC patients with ascites or clinical findings indicative of peritonitis. Timing of radiographic studies and site of bowel involvement are also important. Seventy-nine percent of perforations occurred by 30 h from confirmation of diagnosis (by clinical or radiographic criteria). Surgery or autopsy revealed involvement of the ileo-cecal region in 89% of cases with the actual site of perforation occurring in this area in 58% of patients.

[Two cases of alimentary tract perforation owing to ingested foreign bodies: diagnosis by CT]

We report the CT diagnosis of two cases of alimentary tract perforation caused by the ingestion of foreign bodies. The first case was a common fish bone perforation of the ileum with postoperative scar. The second case was a rare perforation caused by the impact of an uncooked rice cake on sigmoid colon diverticula. Helical CT scan clearly revealed the fish bone as a linear high-density area in the soft tissue between the right abdominal oblique muscles and ileum, and demonstrated the rice cake as high-density material in the bowel.