Biomedical subjects
Publications and source records attributed to Michael L Nance.
We present a case of malrotation with midgut volvulus in an infant in which we discovered a unique CT sign called the perfusion cut-off sign. We hope this case will help establish this crucial diagnosis in other cases.
OBJECTIVE: The objective of this study was to examine the association between delta V and risk of injury to children involved in frontal motor vehicle crashes. BACKGROUND: Previous studies, primarily focused on adult occupants, have demonstrated the relationship between crash severity, as measured by delta V and injury severity. As children have unique safety needs, these results cannot be directly applied to the pediatric population. METHODS: Case series crash investigation data and clinical injury information were reviewed from a child-focused crash surveillance system. Analyses were performed examining the relationship between the estimated delta V and any AIS > or = 2 or any AIS > or = 3 injury. RESULTS: Detailed crash investigation and clinical data were available on 407 children involved in 235 frontal crashes. The average delta V for all crashes was 29 +/- 16.9 kph [18 +/- 10.5 mph (range, 5-123 kph)]. Delta V was strongly and positively associated with the odds of both an AIS > or = 2 and AIS > or = 3 injury (P < 0.0001). The adjusted odds of at least one AIS > or = 2 injury increased on average by 56% (95% confidence interval [CI], 33%-85%) for each 10 kph increase in delta V. Similarly, the adjusted odds of at least one AIS > or = 3 injury increased on average by 67% (95% CI, 40%-102%) for each 10 kph increase in delta V. The delta V at which 50% of child occupants would be expected to sustain any AIS > or = 2 injury was 37 kph [23.0 mph (95% CI, 32-45 kph)], and any AIS > or = 3 injury was 63 kph [39.1 mph (95% CI, 51-infinity kph)]. CONCLUSION: Delta V is strongly predictive of injury risk for child occupants. As many newer generation cars are now fitted with event data recorders, this information is increasingly available and may become useful as a clinical predictor.
BACKGROUND: Nonoperative management of solid organ injuries (SOI) in children is now the standard of care. Little is know regarding the time to failure for those children requiring operative intervention. We sought to delineate this timeline to operative intervention for the subset of single solid organ injured patients requiring laparotomy. METHODS: The National Trauma Data Bank (NTDB) was queried for the period 1991 to 2003 for all children (age <15) with a single abdominal SOI (kidney, liver, spleen). Children with significant associated head injury (Abbreviated Injury Score; AIS >2) were excluded. Data abstracted included age, organ injury and severity (ICD-9, AIS), and operative procedures. Survival analysis methods were used to evaluate equality of hazard rates (indicating rate of operative intervention by hour). RESULTS: For the period of review, the NTDB contained 2,013 children with a single SOI including 1,813 eligible for review. The mean age was 9.2 +/- 3.8 years with a mean Injury Severity Score (ISS) of 8.6 +/- 6.3. The study population included 224 (12.4%) kidney injuries, 488 (26.9%) liver injuries, and 1,101 (60.7%) splenic injuries. A total of 120 (6.6%) of the patients required an operation for their solid organ injury. The median time to operation was 2.4 hours with 61.7% undergoing surgery within 3 hours of arrival, 79.4% within 6 hours, and 89.7% within 24 hours. The operative intervention rate was greatest for splenic injuries (8.7%) followed by liver (3.5%) and kidney (3.1%) injuries. Hazard rates varied significantly by organ injured (p < 0.001) and peaked at 1.5 hours for liver, 2 hours for spleen, and 4.5 hours for kidney. Hazard rates varied significantly by injury severity (p < 0.001) with a peak time to surgery for all severity at 2 hours postadmission. CONCLUSION: Although the patterns for peak time to operative intervention varied for the specific organs injured and injury severity, the need for operative intervention for children with an SOI is established for the vast majority of children within 24 hours of admission.
Evaluation of the pediatric trauma patient frequently requires radiologic studies. Although low-dose radiation from diagnostic radiology is considered safe, lifetime risks per unit dose of radiation are increased in children compared to adults. The total effective dose of radiation to a typical pediatric trauma patient is unknown. We sought to estimate the total effective dose of radiation related to the radiologic assessment of injured children admitted to a pediatric Level I trauma center. We reviewed the radiology records of all children admitted directly to a trauma center in 2002 and tabulated all plain films, computed tomograms, angiographic/fluoroscopic studies, and nuclear medicine studies. Using age-adjusted effective doses (which incorporate biologic effects of radiation), we computed each patient's total effective dose of radiation. Of 506 admitted patients, 394 (78%) underwent at least one radiologic study. The mean total effective dose per patient was 14.9 mSv (median: 7.2 mSv; interquartile range: 2.2-27.4 mSv). On average, computed tomography accounted for 97.5% of total effective dose. Age and injury severity score did not predict total effective dose. We conclude that in pediatric trauma patients, the estimated total effective dose of radiation varied widely. Computed tomography contributed virtually the entire total effective dose. Regarding radiographic evaluation of pediatric trauma patients, the risks and benefits of current practices should continue to be evaluated critically, because lifetime risks associated with radiation exposure are inversely proportional to age at exposure.
OBJECTIVES: To compare the presentation of young children with abdominal trauma caused by high-velocity accidental (HVA), low-velocity accidental (LVA), and inflicted injury, and to test the hypothesis that a delay in care is highly predictive of an inflicted injury. METHODS: We performed a retrospective chart review at an urban Level I pediatric trauma center between 1991 and 2001 of children younger than 6 years who were admitted with abdominal injuries and an Abbreviated Injury Scale (AIS) score > or = 2. Charts were abstracted for demographic information, history of presentation, mechanism of injury, and diagnoses. Accidental injuries were defined as high velocity (motor vehicle crash or a fall from > 10 feet) or low velocity (household trauma, bicycle crash, or a fall from < 10 feet). Inflicted trauma was defined as a constellation of unexplained injuries, confessions by a perpetrator, or disclosure by the victim. RESULTS: Of the 121 children in the study, 77 (64%) had HVA injuries, 31 (26%) had LVA injuries, and 13 (11%) had inflicted injuries. Solid organ injuries (e.g., liver, spleen, and kidney) were most common in all groups, and abused children were significantly more likely to have suffered a hollow viscus injury (p = 0.03). Abused children were also significantly more likely to have suffered injuries with an AIS score >3 and combined hollow viscus and solid organ injuries than the HVA group or the LVA group (p < 0.001). Presentation for medical care occurred within 12 hours for 100% of the HVA group but only 65% of the LVA group, and 46% of the abuse group (p < 0.001). Presentation to care at greater than 12 hours was neither specific nor highly predictive of abuse, as some children with LVA injuries presented for care late despite developing symptoms shortly after their injury occurred (specificity, 65% [95% confidence interval, 45-81%]; positive predictive value, 39% [95% confidence interval, 17-64%]). CONCLUSION: Young children with inflicted abdominal injuries are more likely to have more severe injuries, multiple injuries, and a delay in seeking care than young children with accidental abdominal trauma. However, delay in seeking care is not specific for inflicted injury and occurs in some children with LVA abdominal trauma.
BACKGROUND: Nonoperative management (NOM) is the accepted treatment of most pediatric solid organ injuries (SOI) and, is typically successful. We sought to elucidate predictors of, and the time course to, failure in the subset of children suffering SOI who required operative intervention. METHODS: A retrospective analysis was performed from January 1997 through December 2002 of all pediatric patients (age 0-20 years) with a SOI (liver, spleen, kidney, pancreas) from the trauma registries of seven designated, level I pediatric trauma centers. Failure of NOM was defined as the need for intra-abdominal operative intervention. Data reviewed included demographics, injury mechanism, injury severity (ISS, AIS, SOI grade, and GCS), and outcome. For the failures of NOM, time to operation and relevant clinical variables were also abstracted. A summary AIS (sAIS) was calculated for each patient by summing the AIS values for each SOI, to account for multiple SOI in the same patient. Univariate and multivariate analyses were employed, and significance was set at p < 0.05. RESULTS: A total of 1,880 children were identified. Of these, 62 sustained nonsurvivable head injuries that precluded assessment of NOM outcome and were thus excluded. The remaining 1,818 patients comprised the overall study population. There were 1,729 successful NOM patients (controls -- C) and 89 failures (F), for an overall NOM failure rate of 5%. For isolated organ injuries, the failure rates were: kidney 3%, liver 3%, spleen 4%, and pancreas 18%. There were 14 deaths in the failure group from nonsalvageable injuries (mean ISS = 54 +/- 15). The two groups did not differ with respect to mean age or gender. An MVC was the most common injury mechanism in both groups. Only bicycle crashes were associated with a significantly increased risk of failing NOM (RR = 1.76, 95% CI = 1.02-3.04, p < 0.05). Injury severity and organ specific injuries were associated with NOM failure. When controlling for ISS and GCS, multivariate regression analysis confirmed that a sAIS > or = 4, isolated pancreatic injury, and >1 organ injured were significantly associated with NOM failure (p < 0.01). The median time to failure was 3 hours (range, 0.5-144 hours) with 38% having failed by 2 hours, 59% by 4 hours, and 76% by 12 hours. CONCLUSIONS: Failure of NOM is un common (5%) and typically occurs within the first 12 hours after injury. Failure is associated with injury severity and multiplicity, as well as isolated pancreatic injuries.
PURPOSE: Management of civilian penetrating colon injuries in the adult has evolved from the universal use of fecal diversion to the highly selective use of colostomy. We hypothesized that a similar management approach was appropriate for the pediatric population. METHODS: A retrospective review of pediatric patients (age <17 years) with a penetrating colorectal injury was performed at six Level I trauma centers for the period January 1990 through June 2001. RESULTS: For the period of review, 53 children with a penetrating colorectal injury were identified. Firearms caused 89 percent of the injuries. The colon was injured in 83 percent (n = 44) of patients and the rectum in 17 percent (n = 9) of patients. The colorectal injury was managed without colostomy in 62 percent (n = 33) and with colostomy in 38 percent (colon = 11, rectum = 9). All rectal injuries were treated with colostomy. The hospital length of stay was longer in the colostomy group (17.6 days vs. 11.4 days). The complication rate was higher in the colostomy group (55 percent vs. 27 percent), which included two patients with stoma-related complications. There was no mortality in this series. CONCLUSIONS: Primary repair was used safely in most cases of civilian penetrating colon injuries in the pediatric population. All rectal injuries were treated with colostomy in this series. Fecal diversion was used selectively. Colostomy was performed for selected cases of colon wounds associated with shock, multiple blood transfusions, multiple other injuries, extensive contamination, and high-velocity weapons. In the absence of these associated factors, primary repair appears justified.
PURPOSE: To understand the natural history of right congenital diaphragmatic hernia (CDH), the authors retrospectively reviewed 27 cases of right CDH that presented for prenatal evaluation or postnatal treatment. METHODS: Between 1995 and September 2002, a total of 194 cases of fetal CDH were evaluated and included 22 right-sided defects. The authors reviewed prenatal diagnostic studies (ultrasound scan, magnetic resonance imaging [MRI] echocardiography) and pre- and postnatal outcomes in these 22 cases of right CDH. Five additional cases of right CDH without a prenatal diagnosis were reviewed. RESULTS: The mean gestational age at evaluation was 26.1 weeks. The lung area to head circumference ratio (LHR) ranged from 0.32 to 2.5. In all cases, the fetal liver was herniated into the right chest. Associated anomalies were common. There were no karyotype abnormalities (17 of 22 tested). There were 4 terminations. Nine of the 18 (50%) continuing pregnancies had polyhydramnios, premature rupture of membranes, or preterm labor. The mean gestational age at birth was 36.8 weeks. One patient underwent tracheal occlusion at 27 weeks, and 2 patients died before postnatal repair. Overall survival rate (22 prenatal plus 5 postnatal diagnoses) was 19 of 27 (70%). Postnatal survival rate was 19 of 23 (83%). A Gore-tex (W. L. Gore and Associates, Flagstaff, AZ) patch was utilized in 14 of 21 neonates undergoing surgery. Twelve of 23 (52%) required extracorporeal membrane oxygenation (ECMO) with a 75% survival rate. Significant morbidity occurred in 10 of 19 survivors and included neurologic sequelae in 6 of 19 (32%). CONCLUSIONS: MRI was helpful in the determination of liver position and confirmation of diagnosis. The high incidence of preterm complications, frequent need for ECMO, and high prevalence of comorbidities are indicative of the severity of this CDH population and warrant close prenatal surveillance and delivery at a tertiary care center with ECMO capability.
PURPOSE: Most children and adults with blunt splenic injuries are treated nonoperatively by well-established management protocols. The "blush sign" is an active pooling of contrast material within or around the spleen seen during intravenous enhanced computed tomography (CT) scan. Adult treatment algorithms often include the "blush sign" as an indication for embolization or surgical intervention. This study was designed to evaluate the implications of the "blush sign" in children with blunt splenic injuries. METHODS: A review was performed of all children with blunt splenic injuries treated between January 1996 and December 2001 at a level I pediatric trauma center using an established solid organ injury protocol. The demographic, CT imaging, and outcome data were recorded. Treatment was categorized as operative or nonoperative. A single pediatric radiologist retrospectively reviewed all available CT scans to confirm injury grade and the presence or absence of a "blush sign." RESULTS: There were 133 eligible children admitted with blunt splenic trauma, with a mean age of 9.1 years (range, 1 to 15), including 86 children with an abdominal CT available for review. A "blush sign" on initial CT scan was noted in 6 children, all with grade 3 or above splenic injuries, 5 of who were treated nonoperatively. In this series, the single child with a "blush sign" who did not respond to nonoperative treatment had a severe polytrauma requiring urgent splenectomy and left nephrectomy. None of the children died of their splenic injury. CONCLUSIONS: Although associated with higher grades of injury, the blush sign did not mandate embolization or surgical intervention in children with blunt splenic trauma in this series. Severe splenic injuries with a blush sign on the initial CT scan may be successfully treated nonoperatively when using an established treatment protocol. Management should be based primarily on physiological response to injury rather than the radiologic features of the injury.
BACKGROUND: Children involved in motor vehicle crashes (MVC) can sustain bruising of the abdominal wall associated with seat belt restraint. The incidence of bruising and its relationship with significant intraabdominal injuries are not known. METHODS: An analysis of children involved in MVC between December 1998 and November 2002 was performed, using the crash surveillance database from the Partners for Child Passenger Safety (PCPS) project. Optimally (OR) or suboptimally (S-OR) restrained children aged 4 to 15 years were selected. The incidence of abdominal wall bruising was calculated then correlated with the type of restraint as well as any intraabdominal injury with an Abbreviated Injury Scale score > or =2. RESULTS: A total of 147,985 children in 102,548 crashes met study criteria. An abdominal bruise was noted in 1.33% of the children (n = 1,967; 881 OR and 1,086 S-OR). Significant intraabdominal injury was present in 309 children (0.21%, 95% CI 0.13 to 0.33), including 69 OR and 240 S-OR. The sensitivity, specificity, and positive and negative predictive values of abdominal wall bruising for a significant intraabdominal injury were 73.5%, 98.8%, 11.5%, and 99.9%, respectively. Children with a bruise were substantially more likely to have an intraabdominal injury than children without a bruise. (Odds Ratio 232.1, 95% CI, 75.9 to 710.3) Among those children with an abdominal bruise, 1% required an abdominal operation (n = 20). CONCLUSIONS: Abdominal wall bruising was relatively uncommon in both OR and S-OR children. Among restrained children involved in MVC, those with a bruise were 232 times more likely to have a significant intraabdominal injury when compared with those without a bruise. It is imperative to pursue intraabdominal injury in children with a bruise of the abdominal wall after MVC.
BACKGROUND/PURPOSE: Pain is an inevitable consequence of injury. Accurate assessment and treatment of a child's pain after injury is essential. This study sought to describe children's pain with injury and to elucidate the concordance of parental and self-reported pain in a pediatric traffic-injured population. METHODS: Children (5 to 17 years) admitted for traffic-related injuries and 1 parent were invited to participate in the study. Consented participants were interviewed within 1 month of injury. Participants were asked to rate current and worst pain on 2 validated pediatric pain assessment scales (Bieri Faces Pain Scale and Color Analogue Scale). Demographic, crash, and injury data were abstracted from the medical record. RESULTS: Data from 276 child-parent dyads show that most children reported clinically significant pain initially after injury. Greater "worst pain" ratings did not correlate with injury severity but were associated with loss of consciousness and extremity fracture. Generally, parent-report of child's pain was concordant with child self-report. CONCLUSIONS: This study shows the feasibility of pain assessment for pediatric injury using 2 validated scales and the appropriateness of parental report when the child is not able to provide self-report. Because pain was not correlated with injury severity, pain assessment and intervention for all children with traumatic injuries is strongly recommended.
A 6-year-old girl sustained an unusual constellation of injuries after blunt trauma sustained in a motor vehicle accident. Transection of the trachea and esophagus were managed successfully by repair through a median sternotomy while the patient was on cardiopulmonary bypass. A cervical spinal injury was fixated with halo traction and a femur fracture with internal fixation.
Penetrating injuries account for 10% to 20% of all pediatric trauma admissions at most centers. Gunshot wounds are responsible for the overwhelming majority of penetrating traumatic injuries and have a significantly higher mortality rate than do blunt injury mechanisms. The management of penetrating injuries can be quite challenging and often requires rapid assessment and intervention. Specific management principles are guided by the anatomic location of injury, the determination of trajectory, and the suspected organs injured. Management approaches have been adopted in large part from the more robust adult experience. However, application of these strategies to similar life-threatening injuries in the pediatric population appears appropriate.
OBJECTIVES: Motor vehicle-pedestrian crashes are one of the leading causes of serious injury in children. Prior studies have focused on child and traffic factors contributing to these crashes. The objective of the current study was to examine the role of driving conditions on the occurrence of motor vehicle crashes involving child pedestrians. METHODS: Detailed information was abstracted for the period January 1994 to December 1999 from the Philadelphia Police Department accident reports for all pediatric (age <18 years) pedestrian crashes in a single, urban county. Data included pedestrian age, road and weather conditions, illumination, pedestrian location, and intent, time of day, and date of incident. RESULTS: For the 6-year period of review, there were 3823 children under 18 years of age struck by motor vehicles (range 518 to 726 crashes per year), representing an average of 1.7 per day and a rate of 181 crashes per 100,000 children per year. The mean age was 7.9 years +/- 3.9 (range 1 to 17 years). Crashes occurred when the street was dry (>90%), with no adverse weather conditions (>90%), and during daylight hours or under streetlights (>92%). The most frequent day of the week was Friday (18.1%). The most common time of day was 3:00 to 6:00 PM (38.7%). The spring months (39.1%) predominated, with May (14.0%) being the most common month and January the least. When the circumstances were known, children were struck crossing in midblock 87.9% of cases and crossing behind a vehicle 38.8% of the time; only 4.8% were struck while playing in the street. Injuries as reported by the police exceeded minor in 32.3% with an overall fatality rate of 0.7%. CONCLUSIONS: Urban pediatric pedestrian crashes are common and occur most frequently during optimal driving conditions (good lighting, a dry road, and good weather). The data also suggest that pedestrian crashes are related to the saturation of the streets with children (optimal play conditions) compounded by poor street-crossing technique. Prevention efforts should reinforce the fact that optimal driving conditions are also likely to represent optimal conditions for child play and may increase the risk for pediatric pedestrian injuries through increased exposure.
BACKGROUND: The American Academy of Pediatrics has established guidelines for optimal, age-appropriate child occupant restraint. While optimal restraint has been shown to reduce the risk of injuries overall, its effect on specific types of injuries, in particular abdominal injuries, has not been demonstrated. METHODS: Cross-sectional study of children aged younger than 16 years in crashes of insured vehicles in 15 states, with data collected via insurance claims records and a telephone survey. A probability sample of 10927 crashes involving 17132 restrained children, representing 210926 children in 136734 crashes was collected between December 1, 1998 and May 31, 2002. Restraint use was categorized as optimal or suboptimal based on current American Academy of Pediatrics guidelines. The outcome of interest, abdominal injury, was defined as any reported injury to an intra-abdominal organ of Abbreviated Injury Scale >or=2 severity. RESULTS: Among all restrained children, optimal was noted in 59% (n = 120473) and suboptimal in 41% (n = 83555). An associated abdominal organ injury was noted in 0.05% (n = 62) of the optimal restrained group and 0.17% (n = 140) of the suboptimal group. After adjusting for age and seating position (front vs. rear), optimally restrained children were more than 3 times less likely [odds ratio 3.51 (95% confidence interval, 1.87-6.60, P < 0.001)] as suboptimally restrained children to suffer an abdominal injury. Of note, there were no abdominal injuries reported among optimally restrained 4- to 8-year-olds. CONCLUSIONS: Optimally restrained children are at a significantly lower risk of abdominal injury than children suboptimally restrained for age. This disparity emphasizes the need for aggressive education efforts aimed not only at getting children into restraint systems, but also the importance of optimal, age-appropriate restraint.
BACKGROUND: Nonoperative management of radiographically defined solid organ injuries has proven highly successful in children with blunt splenic and hepatic injuries. The role of nonoperative management protocols is less well defined for blunt renal injuries. The purpose of this study was to review the management and outcome of a consecutive series of children with blunt renal injury. METHODS: The trauma registry from a Level I pediatric trauma center was reviewed to identify all children (age < 19 years) who were treated for a blunt renal injury for the period January 1995 through December 2002. Demographic, anatomic, physiologic, management, and outcome data were analyzed. RESULTS: For the 8 years of review, 101 children with a blunt renal injury were identified, including 95 with accessible and complete data. The renal injury population had a mean age of 10.4 years (range, 0.5-18 years) and was 72.6% male. The renal injuries were distributed as follows: grade 1, n = 22; grade 2, n = 40; grade 3, n = 20; grade 4, n = 11; and grade 5, n = 2. Hematuria was present in 88.1% of children (in whom urinalysis results were available). Four children had underlying congenital renal anomalies. The mean hospital length of stay and intensive care unit stay were 6.0 and 2.6 days, respectively. Overall, 5 children (5.3%) required laparotomy, including 1 nephrectomy (isolated grade 4 injury) and 1 renorrhaphy, for an overall renal salvage rate of 98.9%. In children with isolated renal injuries (n = 48), one child (2.1%) required laparotomy. Seven children required adjunctive urologic procedures (ureteral stenting, n = 5; cystoscopy/cystogram, n = 2). There were seven deaths (7.4% overall; five because of head injury and two because of severe abdominal bleeding at presentation). CONCLUSION: A nonoperative management strategy was advantageous and successful in pediatric blunt renal injuries (94.7% successful nonoperative rate, 98.9% renal salvage rate). Adjunctive urologic procedures (e.g., ureteral stenting) were beneficial in selected cases.
OBJECTIVES: We analyzed urban-rural differences in intentional firearm death. METHODS: We analyzed 584629 deaths from 1989 to 1999 assigned to 3141 US counties, using negative binomial regressions and an 11-category urban-rural variable. RESULTS: The most urban counties had 1.03 (95% confidence interval [CI]=0.87, 1.20) times the adjusted firearm death rate of the most rural counties. The most rural counties experienced 1.54 (95% CI=1.29, 1.83) times the adjusted firearm suicide rate of the most urban. The most urban counties experienced 1.90 (95% CI=1.50, 2.40) times the adjusted firearm homicide rate of the most rural. Similar opposing trends were not found for nonfirearm suicide or homicide. CONCLUSIONS: Firearm suicide in rural counties is as important a public health problem as firearm homicide in urban counties. Policymakers should become aware that intentional firearm deaths affect all types of communities in the United States.
Although previous research has linked poor seat belt fit to abdominal organ injury for children, few have studied the pattern of pediatric abdominal injuries and its relationship to key characteristics beyond this primary association. In this study, data were obtained from a probability sample of 19,125 children, representing 243,540 children, under age 16 years who were enrolled in an on-going crash surveillance system which links insurance claims data to validated telephone survey and crash investigation data. The risk of AIS2+ abdominal injury was estimated for various crash, restraint, vehicle and child correlates and multivariate logistic regression was used to identify the relative importance of these predictors. Children 4-8 years of age were at the highest risk of abdominal injury: they were 24.5 times and 2.6 times more likely to sustain an AIS2+ abdominal injury than those 0-3 years and 9-15 years, respectively. The injury risk for children 4-8 years of age was 6 and 10 times higher in passenger cars and SUVs, respectively, compared to minivans. No reduction in abdominal injury risk was seen with rear seating. The role of direction of impact on injury risk varied by child age indicating diverse injury sources influenced by developmental differences and changes in restraint practices among the age groups. The data suggested a trade-off between head/face injury and abdominal injury: for those restrained in vehicle seat belts in rear seats, those with an AIS2+ head/face injury were nearly 90% less likely to sustain an abdominal injury than those without a head/face injury. These findings suggest mechanistic hypotheses to be tested with additional in-depth data.