Formative evaluation of standardized training for CT colonographic image interpretation by novice readers.

PURPOSE: To introduce an educational intervention-specifically, a specialized training course-and perform a formative evaluation of the effect of the intervention on novice reader interpretation of computed tomography (CT) colonographic data. MATERIALS AND METHODS: The study was institutional review board approved. Ten normal and 50 abnormal cases, those of 60 patients with 93 polyps-61 polyps 6-9 mm in diameter and 32 polyps 10 mm or larger-were selected from a previously published trial. Seven novice readers underwent initial training that consisted of a 1-day course, reading assignments, a self-study computer module (with 61 limited data sets), observation of an expert interpreting three cases, and full interpretation of 10 cases with unblinding after each case. After training, the observers independently interpreted 60 cases by means of primary two-dimensional reading with unblinding after each case. For each case, the reading time and the location and maximal diameter of the polyp(s) were recorded. A t test was used to evaluate the observers' improvements, and empirical receiver operating characteristic (ROC) curves were constructed. RESULTS: By-patient sensitivities and specificities were determined for each observer. The lowest by-patient sensitivity at the 6 mm or larger polyp threshold was 86%, with 90% specificity. Four observers had 100% by-patient sensitivity at the 10 mm or larger polyp threshold, with 82%-97% specificity. For polyps 10 mm or larger, mean sensitivity and specificity were 98% and 92%, respectively. For the last 20 cases, the average interpretation time per case was 25 minutes. The range of areas under the ROC curve across observers was low: 0.86-0.95. CONCLUSION: In the described polyp-enriched cohort, novice CT colonographic data readers achieved high sensitivity and good specificity at formative evaluation of a comprehensive training program. Use of a similar comprehensive training method might reduce interreader variability in interpretation accuracy and be useful for reader certification.

Suture choice matters in rabbit model of laparoscopic, preperitoneal, inguinal hernia repair.

PURPOSE: We evaluated the effect of different suture materials in a laparoscopic preperitoneal ligation of the patent processus vaginalis in a rabbit survival model. MATERIALS AND METHODS: New Zealand White rabbits underwent laparoscopic assisted preperitoneal ligation of the patent processus vaginalis. The processus vaginalis was closed with silk (n=10), polyglactin 910 (Vicryl(®); Ethicon, a Johnson & Johnson Company, Somerville, NJ) (n=10), or polypropylene (Prolene(®); Ethicon) (n=10). At necropsy, the suture was removed, and repair integrity was evaluated. RESULTS: All rabbits survived to necropsy without complications. No suture material was identified during necropsy of the Vicryl group. Eight (80%) of the Vicryl closures failed, with six (60%) failing at initial inspection. Following removal of suture material, nine (90%) of the Prolene closures failed, and only one (10%) of the silk closures failed (P=.009). CONCLUSIONS: The silk suture resulted in an improved closure rate. Ligation with silk suture probably incited an increased inflammatory response that likely created a scar while persisting long enough for the scar to become established. In contrast, the Vicryl sutures probably failed because the sutures dissolved before a scar was able to fully develop. Finally, the Prolene closures were suture dependent as evidenced by failure when the suture was removed. Nonabsorbable braided suture may improve closure of pediatric indirect inguinal hernias during laparoscopic-assisted preperitoneal ligation.

Where's the difference? Presentation of nosocomial infection in critically ill trauma versus general surgery patients.

BACKGROUND: Diagnosing infection efficiently is integral to managing critically ill patients. Knowing if and how trauma and general surgery patients differ in their presentation of new infectious complications could be useful. We hypothesized these populations would differ in presentation in the intensive care unit (ICU). METHODS: We analyzed data collected prospectively from all 1,657 trauma and general surgery patients admitted to the surgical and trauma ICU (STICU) over a 21-month period. Clinical data from the first day of a newly diagnosed infection were compared for trauma (82% of the series) and general surgery (18%) patients. RESULTS: A total of 10,424 STICU days were included, and 267 nosocomial infections were diagnosed. Trauma patients were younger (50 vs. 62 years; p<0.001) and more likely to be male (78% vs. 46%; p<0.001) than were general surgery patients. Similar percentages of the two groups were infected (11% and 13%, respectively), and infections occurred after a similar number of days in the STICU. The mean maximum temperature on the day prior to diagnosis was higher in trauma patients (38.4°C vs. 37.7°C; p<0.001), and the mean leukocyte count was lower (13,500 vs. 15,800 10(6)/L; p=0.013). General surgery patients were more likely to be hypotensive (13% vs. 2%; p=0.002) and to have a positive fluid balance >2 L on the first day of infection (27% vs. 13%; p=0.02). Respiratory infections were more common in trauma patients (40% vs. 7%; p<0.001), and urinary tract infections were less common (19% vs. 36%; p=0.011). CONCLUSION: Differences exist in how new infections manifest in trauma and general surgery patients in the ICU. General surgery patients appeared sicker on their first day of infection, as evidenced by a higher leukocyte count, lower blood pressure, and substantial positive fluid balance. Intensivists may need differing thresholds for triggering infection workups when employed in a mixed unit.

Diagnosis of infection after splenectomy for trauma should be based on lack of platelets rather than white blood cell count.

BACKGROUND: There is a lack of evidence-based criteria to assist the diagnosis of infection following trauma splenectomy (TS). However, the literature suggests that white blood cell count (WBC) is associated with infection in patients who undergo TS. We sought to find whether there exist key differences in laboratory and clinical parameters that can assist the diagnosis of infection after TS. METHODS: We evaluated all consecutive trauma patients who had undergone TS at a Level 1 trauma center from 2005 to 2011 for the development of infection. To do this, we compared the values of demographic, laboratory, and clinical variables of infected and non-infected patients on odd post-operative days (POD) in the period from 1-15 days after TS. RESULTS: Of 127 patients who underwent TS, 25 died within 48 h after the procedure and were excluded from our analysis, leaving, 102 patients for investigation. In the 41 (40%) patients who developed an infection, the mean day for the first infectious episode was POD 7 (range, POD 4-14). The three most common infections were pneumonia (51%), urinary tract infection (24%), and bacteremia (20%). An evaluation of laboratory and clinical parameters showed no differences in the WBC of the patients who did and did not develop infections at any time in the 15 d after TS. However, the platelet count was statistically significantly higher in non-infected patients on POD 3-9 and on POD 13, and maximal body temperature was statistically significantly higher in the infected group of patients during the first week after TS. Differences in laboratory and clinical values of the infected and non-infected patients were greatest on POD 5. CONCLUSIONS: Patients who undergo TS have high rates of infectious complications. The WBC is not a reliable predictor of infection in these patients in the 2 wks following TS. However, patients who do not develop infection after TS have statistically significantly higher absolute platelet counts and rates of change in their daily platelet counts than those who develop infection.

Bacterial species-specific hospital mortality rate for intra-abdominal infections.

BACKGROUND: Intra-abdominal infections (IAIs) are a major cause of morbidity and death. We hypothesized that the involvement of specific organisms would predict death independently. PATIENTS AND METHODS: All patients with IAIs treated at an academic tertiary-care facility over eight years (June 1999-June 2007) were included. The data collected were demographics, co-morbidities, source of infection, intra-abdominal culture results, type of infection (community-acquired vs. nosocomial), type of intervention (operative vs. percutaneous drainage), and outcome. The Charlson Comorbidity Index and multiple organ dysfunction score (MODS) were used in the analysis. RESULTS: A total of 389 patients were admitted for 452 infection episodes (IEs) during the study period. None of the 129 patients with appendiceal-related infections died, and these patients were excluded from further analysis. Thus, 323 non-appendiceal IEs were evaluated. The overall mortality rate was 8.7%. The mean age of the patients was 54 y, and 50% of them were male. Intra-abdominal cultures were obtained from 303 IEs (93.8%). The most common cause of IAI was post-operative infection (44%). There were 49 distinct species isolated. The most common were Enterococcus (105), Escherichia coli (75), Streptococcus (62), Staphylococcus (51), and Bacteroides (46). Bivariable analysis revealed multiple risk factors associated with death. Logistic regression demonstrated that independent risk factors for death were age ≥65 years (odds ratio [OR] 3.92), cardiac event (OR=8.17), catheter-related blood stream infection (OR=6.16), and growth of Clostridium (OR=13.03). The growth of Streptococcus was predictive of survival. The C statistic was 0.89. CONCLUSIONS: In addition to age and intrinsic patient factors, the presence of specific bacterial organisms independently predicts death in patients with non-appendiceal IAI.

Pediatric abdominal wall defects.

This article reviews the incidence, presentation, anatomy, and surgical management of abdominal wall defects found in the pediatric population. Defects such as inguinal hernia and umbilical hernia are common and are encountered frequently by the pediatric surgeon. Recently developed techniques for repairing these hernias are aimed at improving cosmesis and decreasing pain while maintaining acceptably low recurrence rates. Less common conditions such as femoral hernia, Spigelian hernia, epigastric hernia, lumbar hernia, gastroschisis, and omphalocele are also discussed. The surgical treatment of gastroschisis and omphalocele has undergone some advancement with the use of various silos and meshes.

Anterior abdominal stab injury: a comparison of self-inflicted and intentional third-party stabbings.

BACKGROUND: There is minimal literature comparing self-inflicted (SI) with non-self-inflicted (NSI) anterior abdominal stab wounds (AASW). METHODS: Adult patients treated at a level 1 trauma center from 2006 through 2011 with an AASW were reviewed. RESULTS: There were 215 patients with an AASW; 20% were SI. NSI patients had more nonabdominal injuries (47% vs 16%, P < .01) and disposition directly to the operating room (45% vs 26%, P = .02). Intra-abdominal injury rates were similar. One hundred twenty-eight patients had isolated AASWs; 28% were SI. SI patients had higher admission rates (86% vs 63%, P = .01). One hundred three patients had isolated stable/asymptomatic AASWs; 31% were SI. SI patients had more admissions (84% vs 52%, P < .01), had higher intensive care unit admission rates (23% vs 5%, P = .01), longer LOS (3.2 vs 1.4, P < .01), and higher hospital charges ($18,000 vs $11,000, P < .01). The rates of intra-abdominal injury were again similar. CONCLUSIONS: Controlling for extra-abdominal injuries, SI AASW patients have similar rates of intra-abdominal injury but use more resources.

Continued rationale of why hospital mortality is not an appropriate measure of trauma outcomes.

BACKGROUND: We hypothesized that standardized withdrawal of care (WOC) practices and an aggressive long-term acute care facility (LTAC) discharge protocol could change hospital mortality and national ranking among trauma centers. STUDY DESIGN: Patients who died while admitted to the trauma service at a level 1 trauma center were classified as either an "LTAC candidate" or "not a LTAC candidate" at 4 time points before death. RESULTS: A total of 216 patients died, and 48% had WOC. Hospital mortality was 3.3%. More than 26% of these qualified as LTAC candidates. The aggressive LTAC discharge protocol reduced hospital mortality by .9%. This was sufficient to move a trauma center into a lower quartile on the National Trauma DataBank benchmark report for 2009. CONCLUSIONS: [corrected] It is possible to reduce hospital mortality and improve quality ranking with standardized WOC and LTAC discharge protocols. This highlights the importance of measuring outcomes beyond discharge.

Stitch versus scar--evaluation of laparoscopic pediatric inguinal hernia repair: a pilot study in a rabbit model.

BACKGROUND: Many have questioned whether the laparoscopic, percutaneous hernia repair technique is as durable as an open repair in which the sac is divided and ligated. We set out to assess if the suture alone causes enough injury and scar over time to obliterate the internal ring. MATERIALS AND METHODS: In total, 28 male rabbits with congenital patent processus vaginalis underwent laparoscopic repair with the subcutaneous endoscopically assisted ligation technique. For Group 1 the repairs were evaluated laparoscopically at predetermined time points before and after removal of the ligating suture. Group 2 assessed the effect of sharp peritoneal trauma at the time of repair and was evaluated at 2 and 4 weeks. RESULTS: When durability of repair with suture alone was evaluated, all repairs failed after insufflation to 35 mm Hg after suture removal out to a time point of 12 weeks. In the peritoneal trauma group, at the 2- and 4-week survival time point, 87.5% and 100%, respectively, of repairs remained intact after removal of suture. In contrast, only 25% and 12.5%, respectively, of defects remained closed in the animals repaired with suture ligation alone. CONCLUSIONS: The laparoscopic, percutaneous hernia repair may rely heavily on the suture itself to prevent recurrence. In the event of suture failure, this could lead to an increasingly high recurrence rate. The addition of minor peritoneum trauma may induce sufficient scarring to provide a more durable repair.