Delay in diagnosis and treatment of blunt intestinal perforation does not adversely affect prognosis in the pediatric trauma patient.

BACKGROUND: Blunt intestinal injury (BII) requiring surgical intervention in the pediatric trauma population remains difficult to diagnose. We sought to analyze whether delay in treatment in the event of perforation had an adverse affect on patient outcome. METHODS: A multi-institutional retrospective chart review by the members of the American Pediatric Surgical Association Committee on Trauma was initiated after the approval of Institutional Review Board at each of the 18 institutions. All children 12 hours) based on time from injury to intervention and whether they had perforation or not. Early and late complications as well as hospital days, injury severity score, and time to full feeds were compared in each group. There were two deaths from an abdominal source in the <6-hour nonperforation group, one in the 6-hour perforation group, and one in the 6-hour to 12-hour nonperforation group. Injury severity score was significantly greater in the <6-hour intervention group regardless of perforation status. There was no correlation between time to surgery and complication rate nor was there a significant increase in hospital days. CONCLUSIONS: These data suggest that delay in operative intervention does not have a significant effect on prognosis after pediatric blunt intestinal perforation. Appropriate observation and serial examination rather than repeat computed tomography and/or urgent exploration would appear adequate when the diagnosis is in question.

Use of Laparoscopy in Pediatric Blunt and Spleen Injury: An Unexpectedly Common Procedure After Cessation of Bleeding.

Background: Recently, several series have reported the use of laparoscopy in pediatric trauma, most commonly for bowel and pancreatic injury within the first 12 or 24 hours. During a multicenter trial at 10 Level 1 pediatric trauma centers, selective use of laparoscopy in children with blunt liver or spleen injury (BLSI) was noted. A secondary analysis was performed to describe the frequency and application of these procedures to pediatric BLSI. Patients and Methods: Prospective data were collected on all children age ≤18 years with BLSI presenting to 1 of 10 pediatric trauma centers. An unplanned secondary analysis of children who underwent laparoscopy was done. Results: Of 1008 children with BLSI, 59 initially underwent a laparotomy, but 11 underwent a laparoscopic procedure during their index admission; 1 of these was 22 hours postlaparotomy and 2 others were laparoscopy-assisted and converted to laparotomy. Median age of patients undergoing a laparoscopic procedure was 11.5 years (interquartile range [IQR]: 5.8-16.4). Laparoscopy was performed at 7 of the 10 centers. Median time to surgery was 42 hours (IQR: 8-96). Most patients had a liver (n = 6) injury; 4 had spleen and 1 had both. One of the laparoscopies was for pancreatic surgery, and 2 were for bowel injury (but converted to open). Conclusions: Laparoscopy was utilized in 16% of children requiring abdominal surgery after BLSI, with a median time of 42 hours postinjury. Uses included diagnostic laparoscopy, drain placement, laparoscopic pancreatectomy, and washout of hematoma.

Negative Focused Abdominal Sonography for Trauma examination predicts successful nonoperative management in pediatric solid organ injury: A prospective Arizona-Texas-Oklahoma-Memphis-Arkansas + Consortium study.

BACKGROUND: Focused Abdominal Sonography for Trauma (FAST) examination has long been proven useful in the management of adult trauma patients, however, its utility in pediatric trauma patients is not as proven. Our goal was to evaluate the utility of a FAST examination in predicting the success or failure of nonoperative management (NOM) of blunt liver and/or spleen (BLSI) in the pediatric trauma population. METHODS: A retrospective analysis of a prospective observational study of patients younger than 18 years presenting with BLSI to one of ten Level I pediatric trauma centers between April 2013 and January 2016. 1,008 patients were enrolled and 292 had a FAST examination recorded. We analyzed failure of NOM of BLSI in the pediatric trauma population. We then compared FAST examination alone or in combination with the pediatric age adjusted shock index (SIPA) as it relates to success of NOM of BLSI. RESULTS: Focused Abdominal Sonography for Trauma examination had a negative predictive value (NPV) of 97% and positive predictive value (PPV) of 13%. The odds ratio of failing with a positive FAST examination was 4.9 and with a negative FAST was 0.20. When combined with SIPA, a positive FAST examination and SIPA had a PPV of 17%, and an odds ratio for failure of 4.9. The combination of negative FAST and SIPA had an NPV of 96%, and the odds ratio for failure was 0.20. CONCLUSION: Negative FAST is predictive of successful NOM of BLSI. The addition of a positive or negative SIPA score did not affect the PPV or NPV significantly. Focused Abdominal Sonography for Trauma examination may be useful clinically in determining which patients are not at risk for failure of NOM of BLSI and do not require monitoring in an intensive care setting. LEVEL OF EVIDENCE: Prognostic study, level IV; therapeutic/care management, level IV.

Adherence to APSA activity restriction guidelines and 60-day clinical outcomes for pediatric blunt liver and splenic injuries (BLSI).

BACKGROUND: After NOM for BLSI, APSA guidelines recommend activity restriction for grade of injury +2 in weeks. This study evaluates activity restriction adherence and 60 day outcomes. METHODS: Non-parametric tests and logistic regression were utilized to assess difference between adherent and non-adherent patients from a 3-year prospective study of NOM for BLSI (≤18 years). RESULTS: Of 1007 children with BLSI, 366 patients (44.1%) met the inclusion criteria of a completed 60 day follow-up; 170 (46.4%) had liver injury, 159 (43.4%) had spleen injury and 37 (10.1%) had both. Adherence to recommended activity restriction was claimed by 279 (76.3%) patients; 49 (13.4%) reported non-adherence and 38 (10.4%) patients had unknown adherence. For 279 patients who adhered to activity restrictions, unplanned return to the emergency department (ED) was noted for 35 (12.5%) with 16 (5.7%) readmitted; 202 (72.4%) returned to normal activity by 60 days. No patient bled after discharge. There was no statistical difference between adherent patients (n = 279) and non-adherent (n = 49) for return to ED (χ2 = 0.8 [p < 0.4]) or readmission (χ2 = 3.0 [p < 0.09]); for 216 high injury grade patients, there was no difference between adherent (n = 164) and non-adherent (n = 30) patients for return to ED (χ2 = 0.6 [p < 0.4]) or readmission (χ2 = 1.7 [p < 0.2]). CONCLUSION: For children with BLSI, there was no difference in frequencies of bleeding or ED re-evaluation between patients adherent or non-adherent to the APSA activity restriction guideline. LEVEL OF EVIDENCE: Level II, Prognosis.

Reimaging in pediatric blunt spleen and liver injury.

BACKGROUND: APSA guidelines do not recommend routine reimaging for pediatric blunt liver or spleen injury (BLSI). This study characterizes the symptoms, reimaging, and outcomes associated with a selective reimaging strategy for pediatric BLSI patients. METHODS: A planned secondary analysis of reimaging in a 3-year multi-site prospective study of BLSI patients was completed. Inclusion required successful nonoperative management of CT confirmed BLSI without pancreas or kidney injury and follow up at 14 or 60 days. Patients with re-injury after discharge were excluded. RESULTS: Of 1007 patients with BLSI, 534 (55%) met inclusion criteria (median age: 10.18 [IQR: 6, 14]; 62% male). Abdominal reimaging was performed on 27/534 (6%) patients; 3 of 27 studies prompting hospitalization and/or intervention. Abdominal pain was associated with reimaging, but decreased appetite predicted imaging findings associated with readmission and intervention. CONCLUSION: Selective abdominal reimaging for BLSI was done in 6% of patients, and 11% of studies identified radiologic findings associated with intervention or re-hospitalization. A selective reimaging strategy appears safe, and even reimaging symptomatic patients rarely results in intervention. Reimaging after 14 days did not prompt intervention in any of the 534 patients managed nonoperatively. LEVEL OF EVIDENCE: Level II, Prognosis.

Hyperglycemia and infections in pediatric trauma patients.

Hyperglycemia has been associated with poor outcome in children with head injuries and burns. However, there has not been a correlation noted between hyperglycemia and infections in severely injured children. The trauma registry of a Level I trauma center was queried for injured children <13 years admitted between July 1, 1999 and August 31, 2003. The records of severely injured children [Injury Severity Score (ISS) > 15] were examined for survival, age, weight, ISS, infection, length of stay (LOS), and maximum glucose levels within the first 24 hours of injury (D1G). Statistical analysis was performed using a t test, Fisher's exact test, a Mann-Whitney Rank Sum test, or Kendall's Tau where appropriate. Eight hundred and eighty eight children under 13 years of age were admitted. One hundred and nine had an ISS > 15, and 57 survived to discharge with measured D1G. Patients excluded were those who died in less than 72 hours or had an LOS less than 72 hours. The survivors were divided into high glucose (> or =130 mg/dL; n = 48) and normal glucose (<130 mg/dL; n = 9). There was no difference between the groups with respect to age, weight, incidence of head injury, and ISS. An elevated D1G correlated with an increased risk of infection (P = 0.05) and an increased LOS (P = 0.01). These data suggest that severely injured children are often hyperglycemic in the first 24 hours after injury. Hyperglycemia in this study population correlated with an increased incidence of infection and increased length of stay. This suggests that strict control of hyperglycemia in injured children may be beneficial.

The incidence of delayed splenic bleeding in pediatric blunt trauma.

BACKGROUND: One of the concerns associated with nonoperative management of splenic injury in children has been delayed splenic bleed (DSB) after a period of hemostasis. This study evaluates the incidence of DSB from a multicenter 3-year prospective study of blunt splenic injuries (BSI). METHODS: A 3-year prospective study was done to evaluate nonoperative management of pediatric (≤18years) BSI presenting to one of 10 pediatric trauma centers. Patients were tracked at 14 and 60days. Descriptive statistics were used to summarize patient and injury characteristics. RESULTS: During the study period, 508 children presented with BSI. Median age was 11.6 [IQR: 7.0, 14.8]; median splenic injury grade was 3 [IQR: 2, 4]. Nonoperative management was successful in 466 (92%) with 18 (3.5%) patients undergoing splenectomy at the index admission, all within 3h of injury. No patient developed a delayed splenic bleed. At least one follow-up visit was available for 372 (73%) patients. CONCLUSION: A prior single institution study suggested that the incidence of DSB was 0.33%. Based on our results, we believe that the rate may be less than 0.2%. LEVEL OF EVIDENCE: Level II, Prognosis.

The impact of morbid obesity on solid organ injury in children using the ATOMAC protocol at a pediatric level I trauma center.

INTRODUCTION: Obesity is an epidemic in the pediatric population. Childhood obesity in trauma has been associated with increased incidence of long-bone fractures, longer ICU stays, and decreased closed head injuries. We investigated for differences in the likelihood of failure of non-operative management (NOM), and injury grade using a subset of a multi-institutional, prospective database of pediatric patients with solid organ injury (SOI). METHODS: We prospectively collected data on all pediatric patients (<18years) admitted for liver or splenic injury from September 2013 to January 2016. SOI was managed based upon the ATOMAC protocol. Obesity status was derived using CDC definitions; patients were categorized as non-obese (BMI <95th percentile) or obese (BMI ≥95th percentile). The ISS, injury grade, and NOM failure rate were calculated among other data points. RESULTS: Of 1012 patients enrolled, 117 were identified as having data regarding BMI. Eighty-four percent of patients were non-obese; 16% were obese. The groups did not differ by age, sex, mechanism of injury, or associated injuries. There was no significant difference in the rate of failure of non-operative management (8.2% versus 5.3%). Obesity was associated with higher likelihood of severe (grade 4 or 5) hepatic injury (36.8% versus 15.3%, P=0.048) but not a significant difference in likelihood of severe (grade 4 or 5) splenic injury (15.3% versus 10.5%, P=0.736). Obese patients had a higher mean ISS (22.5 versus 16.1, P=0.021) and mean abdominal AIS (3.5 versus 2.9, P=0.024). CONCLUSION: Obesity is a risk factor for more severe abdominal injury, specifically liver injury, but without an associated increase in failure of NOM. This may be explained by the presence of hepatic steatosis making the liver more vulnerable to injury. A protocol based upon physiologic parameters was associated with a low rate of failure regardless of the pediatric obesity status. LEVEL OF EVIDENCE: Level II prognosis.

Prospective validation of the shock index pediatric-adjusted (SIPA) in blunt liver and spleen trauma: An ATOMAC+ study.

BACKGROUND: Age-adjusted pediatric shock index (SIPA) does not require knowledge of age-adjusted blood pressure norms, yet correlates with mortality, serious injury, and need for transfusion in trauma. No prospective studies support its validity. METHODS: A multicenter prospective observational study of patients 4-16years presenting April 2013-January 2016 with blunt liver and/or spleen injury (BLSI). SIPA (maximum heart rate/minimum systolic blood pressure) thresholds of >1.22, >1.0, and >0.9 in the emergency department were used for 4-6, 7-12 and 13-16year-olds, respectively. Patients with ISS ≤15 were excluded to conform to the original paper. Discrimination outcomes were compared between SIPA and shock index (SI). RESULTS: Of 1008 patients, 386 met inclusion. SI was elevated in 321, and SIPA elevated in 282. The percentage of patients with elevated index (SI or SIPA) and blood transfusion within 24 hours (30% vs 34%), BLSI grade ≥3 requiring transfusion (28% vs 32%), operative intervention (14% vs 16%) and ICU admission (64% vs 67%) was higher in the SIPA group. CONCLUSION: SIPA was validated in this multi-institutional prospective study and identified a higher percentage of children requiring additional resources than SI in BLSI patients. SIPA may be useful for determining necessary resources for injured patients with BLSI. LEVEL OF EVIDENCE: Level II prognosis.

Failure of nonoperative management of pediatric blunt liver and spleen injuries: A prospective Arizona-Texas-Oklahoma-Memphis-Arkansas Consortium study.

BACKGROUND: Nonoperative management (NOM) is standard of care for most pediatric blunt liver and spleen injuries (BLSI); only 5% of patients fail NOM in retrospective reports. No prospective studies examine failure of NOM of BLSI in children. The aim of this study was to determine the frequency and clinical characteristics of failure of NOM in pediatric BLSI patients. METHODS: A prospective observational study was conducted on patients 18 years or younger presenting to any of 10 Level I pediatric trauma centers April 2013 and January 2016 with BLSI on computed tomography. Management of BLSI was based on the Arizona-Texas-Oklahoma-Memphis-Arkansas Consortium pediatric guideline. Failure of NOM was defined as needing laparoscopy or laparotomy. RESULTS: A total of 1008 patients met inclusion; 499 (50%) had liver injury, 410 (41%) spleen injury, and 99 (10%) had both. Most patients were male (n = 624; 62%) with a median age of 10.3 years (interquartile range, 5.9, 14.2). A total of 69 (7%) underwent laparotomy or laparoscopy, but only 34 (3%) underwent surgery for spleen or liver bleeding. Other (nonexclusive) operations were for 21 intestinal injuries; 15 hematoma evacuations, washouts, or drain placements; 9 pancreatic injuries; 5 mesenteric injuries; 3 diaphragm injuries; and 2 bladder injuries. Patients who failed were more likely to receive blood (52 of 69 vs. 162 of 939; p < 0.001) and median time from injury to first blood transfusion was 2.3 hours for those who failed versus 5.9 hours for those who did not (p = 0.002). Overall mortality rate was 24% (8 of 34) in those who failed NOM due to bleeding. CONCLUSION: NOM fails in 7% of children with BLSI, but only 3% of patients failed for bleeding due to liver or spleen injury. For children failing NOM due to bleeding, the mortality was 24%. LEVEL OF EVIDENCE: Therapeutic study, level II.

Hypotension and the need for transfusion in pediatric blunt spleen and liver injury: An ATOMAC+ prospective study.

PURPOSE: Children with blunt liver or spleen injury (BLSI) requiring early transfusion may present without hypotension despite significant hypovolemia. This study sought to determine the relationship between early transfusion in pediatric BLSI and hypotension. METHODS: Secondary analysis of a 10-institution prospective observational study was performed of patients 18years and younger presenting with BLSI. Patients with central nervous system (CNS) injury were excluded. Children receiving blood transfusion within 4h of injury were evaluated. Time to first transfusion, vital signs, and physical exams were analyzed. Patients with hypotension were compared to those without hypotension. RESULTS: Of 1008 patients with BLSI, 47 patients met inclusion criteria. 22 (47%) had documented hypotension. There was no statistical difference in median time to first transfusion for those with or without hypotension (2h vs. 2.5h, p=0.107). The hypotensive group was older (median 15.0 versus 9.5years; p=0.007). Median transfusion volume in the first 24h was 18.2mL/kg (IQR: 9.6, 25.7) for those with hypotension and 13.9mL/kg (IQR: 8.3, 21.0) for those without (p=0.220). Mortality was 14% (3/22) in children with hypotension and 0% (0/25) in children without hypotension. CONCLUSION: Hypotension occurred in less than half of patients requiring early transfusion following pediatric BLSI suggesting that hypotension does not consistently predict the need for early transfusion. TYPE OF STUDY: Secondary analysis of a prospective observational study. LEVEL OF EVIDENCE: Level IV cohort study.

A paradigm for achieving successful pediatric trauma verification in the absence of pediatric surgical specialists while ensuring quality of care.

BACKGROUND: Pediatric trauma centers (PTCs) are concentrated in urban areas, leaving large areas where children do not have access. Although adult trauma centers (ATCs) often serve to fill the gap, disparities exist. Given the limited workforce in pediatric subspecialties, many adult centers that are called upon to care for children cannot sufficiently staff their program to meet the requirements of verification as a PTC. We hypothesized that ATCs in collaboration with a PTC could achieve successful American College of Surgeons (ACS) verification as a PTC with measurable improvements in care. This article serves to provide an initial description of this collaborative approach. METHODS: Beginning in 2008, a Level I PTC partnered with three ATC seeking ACS-PTC verification. The centers adopted a plan for education, simulation training, guidelines, and performance improvement support. Results of ACS verification, patient volumes, need to transfer patients, and impact on solid organ injury management were evaluated. RESULTS: Following partnership, each of the ATCs has achieved Level II PTC verification. As part of each review, the collaborative was noted to be a significant strength. Total pediatric patient volume increased from 128.1 to 162.1 a year (p = 0.031), and transfers out decreased from 3.8% to 2.4% (p = 0.032) from prepartnership to postpartnership periods. At the initial ATC partner site, 10.7 children per year with solid organ injury were treated before the partnership and 11.8 children per year after the partnership. Following partnership, we found significant reductions in length of stay, number of images, and laboratory draws among this limited population. CONCLUSION: The collaborative has resulted in ACS Level II PTC verification in the absence of on-site pediatric surgical specialists. In addition, more patients were safely cared for in their community without the need for transfer with improved quality of care. This paradigm may serve to advance the care of injured children at sites without access to pediatric surgical specialists through a collaborative partnership with an experienced Level I PTC. Further risk-adjusted analysis of outcomes will need to be performed in the future. LEVEL OF EVIDENCE: Therapeutic/care management, level IV.

The effects of balanced blood component resuscitation and crystalloid administration in pediatric trauma patients requiring transfusion in Afghanistan and Iraq 2002 to 2012.

BACKGROUND: Component balanced resuscitation and avoidance of crystalloids in traumatically injured adults requiring massive transfusion are beneficial. Evidence for children is lacking. METHODS: After institutional review board approval was obtained, the Department of Defense Trauma Database identified 1,311 injured children 14 years or younger requiring transfusion after an injury and admitted to a deployed US military hospital from 2002 to 2012. Logistic regression determined risk factors for high-volume (≥40 mL/kg) or massive (≥70 mL/kg) transfusions. The effects of crystalloid and balanced component resuscitation in the first 24 hours were assessed. RESULTS: Nine hundred seven patients had recorded data sufficient for analysis. Two hundred twenty-four children received high-volume transfusion, and 77 received massive transfusions. Mortality was significantly higher for massive transfusions and high-volume transfusions than others (25% vs. 10% and 19% vs. 9%, respectively). Age of less than 4 years, penetrating injury, and Injury Severity Score (ISS) greater than 15 were associated with high-volume transfusions; an ISS greater than 15 and penetrating injury were associated with massive transfusions. Increased crystalloid administration showed a significant positive association with hospital days and intensive care unit days for both massive and high-volume transfusions, as well as a significant positive association with increased ventilator days in patients with high-volume transfusions. Balanced component resuscitation was not associated with improved measured outcomes and was independently associated with a higher mortality when all transfused patients were considered. CONCLUSION: In this cohort, heavy reliance on crystalloid for resuscitation had an adverse effect on outcomes. Balanced component resuscitation did not improve outcomes and was associated with higher mortality when all transfused patients were considered. Further study is needed regarding efficacy and clinical triggers for the implementation of massive transfusion in children. LEVEL OF EVIDENCE: Prognostic study, level IV.

The effects of the addition of a pediatric surgery fellow on the operative experience of the general surgery resident.

Adding fellows to surgical departments with residency programs can affect resident education. Our specific aim was to evaluate the effect of adding a pediatric surgery (PS) fellow on the number of index PS cases logged by the general surgery (GS) residents. At a single institution with both PS and GS programs, we examined the number of logged cases for the fellows and residents over 10 years [5 years before (Time 1) and 5 years after (Time 2) the addition of a PS fellow]. Additionally, the procedure related relative value units (RVUs) recorded by the faculty were evaluated. The fellows averaged 752 and 703 cases during Times 1 and 2, respectively, decreasing by 49 (P = 0.2303). The residents averaged 172 and 161 cases annually during Time 1 and Time 2, respectively, decreasing by 11 (P = 0.7340). The total number of procedure related RVUs was 4627 and 6000 during Times 1 and 2, respectively. The number of cases logged by the PS fellows and GS residents decreased after the addition of a PS fellow; however, the decrease was not significant. Programs can reasonably add an additional PS fellow, but care should be taken especially in programs that are otherwise static in size.

Nonoperative management of blunt liver and spleen injury in children: Evaluation of the ATOMAC guideline using GRADE.

BACKGROUND: Nonoperative management of liver and spleen injury should be achievable for more than 95% of children. Large national studies continue to show that some regions fail to meet these benchmarks. Simultaneously, current guidelines recommend hospitalization for injury grade + 2 (in days). A new treatment algorithm, the ATOMAC guideline, is in clinical use at many centers but has not been prospectively validated. METHODS: A literature review conducted through MEDLINE identified publications after the American Pediatric Surgery Association guidelines using the search terms blunt liver trauma pediatric, blunt spleen trauma pediatric, and blunt abdominal trauma pediatric. Decision points in the new algorithm generated clinical questions, and GRADE [Grading of Recommendations, Assessment, Development, and Evaluations] methodology was used to assess the evidence supporting the guideline. RESULTS: The algorithm generated 27 clinical questions. The algorithm was supported by six 1A recommendations, two 1B recommendations, one 2B recommendation, eight 2C recommendations, and ten 2D recommendations. The 1A recommendations included management based on hemodynamic status rather than grade of injury, support for an abbreviated period of bed rest, transfusion thresholds of 7.0 g/dL, exclusion of peritonitis from a guideline, accounting for local resources and concurrent injuries in the management of children failing to stabilize, as well as the use of a guideline in patients with multiple injuries. The use of more than 40 mL/kg or 4 U of blood to define end points for the guideline, and discharging stable patients before 24 hours received 1B recommendations. CONCLUSION: The original American Pediatric Surgery Association guideline for pediatric blunt solid organ injury was instrumental in improving care, but sufficient evidence now exists for an updated management guideline. LEVEL OF EVIDENCE: Expert opinion, guideline, grades I to IV.

Surgeon-directed ultrasound for trauma is a predictor of intra-abdominal injury in children.

This study investigated the efficacy of surgeon-directed focused assessment with sonography for trauma (FAST) in conjunction with physical exam (PEx) as a predictor of intra-abdominal injury in children. Injured children (ages < or = 17) presenting to a level I trauma center with abdominal trauma were evaluated in the emergency department (ED) by the trauma team of surgical attendings and residents. PEx and FAST were performed immediately upon arrival to the ED and results compared to CT, the standard exam for presence of intra-abdominal injury. Data was collected prospectively from July 1, 2000, until April 30, 2002. One hundred and twenty injured children underwent evaluation of abdominal trauma with PEx, FAST, and abdominal CT. Two patients had false-negative CT scans. Bayesian analysis was applied to the results of the remaining 118 patients. FAST compared with CT findings revealed sensitivity 70 per cent, specificity 100 per cent, positive predictive value 100 per cent, and negative predictive value 92 per cent. FAST results were combined with PEx findings such that either suggestive of intra-abdominal injury was regarded as a "positive exam." Sensitivity was 100 per cent, specificity 74 per cent, positive predictive value 53 per cent, and negative predictive value 100 per cent. Surgeon-directed FAST with consideration of PEx is a predictor of intra-abdominal injury in children.

Effects of hydrogen on the formation of aligned carbon nanotubes by chemical vapor deposition.

Well-aligned carbon nanotubes with controllable properties were grown on porous silicon substrates by thermal chemical vapor deposition. The morphologies of the carbon nanotubes were varied with the introduction of H2 during the catalyst activation and/or carbon nanotube growth processes. It was found that H2 promotes the growth of carbon nanotubes while preventing the formation of spherical amorphous carbon particles. Without the introduction of H2 during the C2H2 thermal decomposition, aligned carbon nanotubes mixed with spherical carbon particles were formed on the substrate. However, with the introduction of H2, pure carbon nanotubes were synthesized. These nanotubes also had uniform diameters of 10-20 nm, which is much smaller than nanotubes synthesized without H2. The average growth rate of nanotubes was also affected by the introduction of hydrogen into the reaction chamber during nanotube growth. With the addition of hydrogen, the average growth rate changed from 78 nm/s to 145 nm/s. A possible growth mechanism, including the effect of a high ratio of H2 to C2H2, is suggested for the growth of these well-aligned carbon nanotubes with uniform diameters.

Blast injury.

Individuals with a blast injury are the victims most likely to be seen by any healthcare professional. An awareness of the potential injuries is important. Individual care should follow standards established for all trauma patients.

Field amputation: response planning and legal considerations inspired by three separate amputations.

BACKGROUND: Surgical procedures in the field are occasionally required as life-saving measures. Few centers have a planned infrastructure for field physician support. Focused efforts are needed to create teams that can meet such needs. Additionally, certain legal issues surrounding these efforts should be considered. Three cases of field dismemberment inspired this call for preparation. METHODS: In one case, an earthquake caused the collapse of a bridge, entrapping a child within a car. A through-knee amputation was required to free the patient with local anesthetic only. The second case was the result of a truck bomb causing the collapse of a building whereby a victim was trapped by a pillar. After retrieval of supplies from a local hospital, a through-knee amputation was performed. The third case involved a young man whose arm became entangled in an oil derrick. This patient was sedated and intubated in an erect position and the arm was amputated. RESULTS: Fortunately, each of these victims survived. However, the care these patients received was unplanned and had the potential for failure. The authors feel that disaster teams, including a surgeon, should be identified in advance as responders to a disaster on short notice. Legal issues including statespecific Good Samaritan laws and financial support systems must also be considered. CONCLUSION: As hospitals and trauma systems prepare for disaster situations, they should consider the eventuality of field dismemberment. This involves identifying a team, including a surgeon, and devising an infrastructure allowing rapid response capabilities, including surgical procedures in the field.

Preoperative symptom duration predicts success in relieving abdominal pain caused by biliary dyskinesia in a pediatric population.

PURPOSE: The objective of this study was to identify factors associated with symptom relief in pediatric patients treated with laparoscopic cholecystectomy (LC) for biliary dyskinesia (BD). METHODS: This was a case-control study of pediatric patients diagnosed with BD between January 2004 and June 2011. Controls were patients with symptom resolution and cases were patients who did not experience symptom relief. RESULTS: Fifty patients met study eligibility, of whom 43 were controls and 7 were cases. Mean follow-up for the cohort was 26.5months. Unadjusted comparisons suggested no significant differences (p>0.05) between the two groups in the distribution of demographic and clinical variables with the exception of preoperative duration of symptoms and presence of comorbidity. After adjusting for comorbidities, the only significant predictor associated with the resolution of symptoms after surgery was preoperative duration of symptoms (OR, 0.37; 95% CI, 0.15-0.94); 96% of patients with symptoms<12months had symptom relief versus 70% with symptoms≥12months. CONCLUSION: Symptoms associated with BD can be successfully relieved with LC. These data suggest patients with preoperative symptoms for less than 12months are the most likely to have symptom relief after surgery.