David H. Wisner

Identification of children at very low risk of clinically-important brain injuries after head trauma: a prospective cohort study

BACKGROUND CT imaging of head-injured children has risks of radiation-induced malignancy. Our aim was to identify children at very low risk of clinically-important traumatic brain injuries (ciTBI) for whom CT might be unnecessary. METHODS We enrolled patients younger than 18 years presenting within 24 h of head trauma with Glasgow Coma Scale scores of 14-15 in 25 North American emergency departments. We derived and validated age-specific prediction rules for ciTBI (death from traumatic brain injury, neurosurgery, intubation >24 h, or hospital admission >or=2 nights). FINDINGS We enrolled and analysed 42 412 children (derivation and validation populations: 8502 and 2216 younger than 2 years, and 25 283 and 6411 aged 2 years and older). We obtained CT scans on 14 969 (35.3%); ciTBIs occurred in 376 (0.9%), and 60 (0.1%) underwent neurosurgery. In the validation population, the prediction rule for children younger than 2 years (normal mental status, no scalp haematoma except frontal, no loss of consciousness or loss of consciousness for less than 5 s, non-severe injury mechanism, no palpable skull fracture, and acting normally according to the parents) had a negative predictive value for ciTBI of 1176/1176 (100.0%, 95% CI 99.7-100 0) and sensitivity of 25/25 (100%, 86.3-100.0). 167 (24.1%) of 694 CT-imaged patients younger than 2 years were in this low-risk group. The prediction rule for children aged 2 years and older (normal mental status, no loss of consciousness, no vomiting, non-severe injury mechanism, no signs of basilar skull fracture, and no severe headache) had a negative predictive value of 3798/3800 (99.95%, 99.81-99.99) and sensitivity of 61/63 (96.8%, 89.0-99.6). 446 (20.1%) of 2223 CT-imaged patients aged 2 years and older were in this low-risk group. Neither rule missed neurosurgery in validation populations. INTERPRETATION These validated prediction rules identified children at very low risk of ciTBIs for whom CT can routinely be obviated. FUNDING The Emergency Medical Services for Children Programme of the Maternal and Child Health Bureau, and the Maternal and Child Health Bureau Research Programme, Health Resources and Services Administration, US Department of Health and Human Services.

Prospective Study of Blunt Aortic Injury: Multicenter Trial of the American Association for the Surgery of Trauma

BACKGROUND Blunt aortic injury is a major cause of death from blunt trauma. Evolution of diagnostic techniques and methods of operative repair have altered the management and posed new questions in recent years. METHODS This study was a prospectively conducted multi-center trial involving 50 trauma centers in North America under the direction of the Multi-institutional Trial Committee of the American Association for the Surgery of Trauma. RESULTS There were 274 blunt aortic injury cases studied over 2.5 years, of which 81% were caused by automobile crashes. Chest computed tomography and transesophageal echocardiography were applied in 88 and 30 cases, respectively, and were 75 and 80% diagnostic, respectively. Two hundred seven stable patients underwent planned thoracotomy and repair. Clamp and sew technique was used in 73 (35%) and bypass techniques in 134 (65%). Overall mortality was 31%, with 63% of deaths being attributable to aortic rupture; mortality was not affected by method of repair. Paraplegia occurred postoperatively in 8.7%. Logistic regression analysis demonstrated clamp and sew (p = 0.002) and aortic cross clamp time of > or = 30 minutes (p = 0.01) to be associated with development of postoperative paraplegia. CONCLUSIONS Rupture after hospital admission remains a major problem. Although newer diagnostic techniques are being applied, at this time aortography remains the diagnostic standard. Aortic cross clamp time beyond 30 minutes was associated with paraplegia; bypass techniques, which provide distal aortic perfusion, produced significantly lower paraplegia rates than the clamp and sew approach.

Penetrating colon injuries requiring resection: Diversion or primary anastomosis? An AAST prospective multicenter study

BACKGROUND The management of colon injuries that require resection is an unresolved issue because the existing practices are derived mainly from class III evidence. Because of the inability of any single trauma center to accumulate enough cases for meaningful statistical analysis, a multicenter prospective study was performed to compare primary anastomosis with diversion and identify the risk factors for colon-related abdominal complications. METHODS This was a prospective study from 19 trauma centers and included patients with colon resection because of penetrating trauma, who survived at least 72 hours. Multivariate logistic regression analysis was used to compare outcomes in patients with primary anastomosis or diversion and identify independent risk factors for the development of abdominal complications. RESULTS Two hundred ninety-seven patients fulfilled the criteria for inclusion and analysis. Overall, 197 patients (66.3%) were managed by primary anastomosis and 100 (33.7%) by diversion. The overall colon-related mortality was 1.3% (four deaths in the diversion group, no deaths in the primary anastomosis group, p = 0.012). Colon-related abdominal complications occurred in 24% of all patients (primary repair, 22%; diversion, 27%; p = 0.373). Multivariate analysis including all potential risk factors with p values < 0.2 identified three independent risk factors for abdominal complications: severe fecal contamination, transfusion of > or = 4 units of blood within the first 24 hours, and single-agent antibiotic prophylaxis. The type of colon management was not found to be a risk factor. Comparison of primary anastomosis with diversion using multivariate analysis adjusting for the above three identified risk factors or the risk factors previously described in the literature (shock at admission, delay > 6 hours to operating room, penetrating abdominal trauma index > 25, severe fecal contamination, and transfusion of > 6 units blood) showed no statistically significant difference in outcome. Similarly, multivariate analysis and comparison of the two methods of colon management in high-risk patients showed no difference in outcome. CONCLUSION The surgical method of colon management after resection for penetrating trauma does not affect the incidence of abdominal complications, irrespective of associated risk factors. Severe fecal contamination, transfusion of > or = 4 units of blood within the first 24 hours, and single-agent antibiotic prophylaxis are independent risk factors for abdominal complications. In view of these findings, the reduced quality of life, and the need for a subsequent operation in colostomy patients, primary anastomosis should be considered in all such patients.

Use of ultrasonography in the patient with acute abdominal trauma

The purpose of this study was to assess the use of ultrasonography in patients with acute abdominal trauma. Five hundred prospective patients, who came to the Emergency Department with acute trauma, were evaluated with ultrasonography and included in this study. The ultrasonographic examination focused on detection of free fluid but included evaluation of parenchymal organs for injury. The physical examination was not used in the statistical analysis of the sonographic findings. In comparing ultrasonography to computed tomography, diagnostic peritoneal lavage, or operative findings, we obtained 24 true positive, 79 true negative, four false positive, and 14 false negative results. Sensitivity of ultrasonography in detecting free fluid in comparison to computed tomography, diagnostic peritoneal lavage, and surgery was 63%, specificity was 95%, accuracy was 85%, positive predictive value was 86%, and negative predictive value was 85%. The most common reason for false negative sonographic results was identification of free fluid in the pelvis on computed tomograms but not on ultrasonograms owing to lack of a full bladder. In none of these instances were the sonographic false negative results of clinical significance. Ultrasonography allowed detection of solid organ injury of the liver in one of seven cases, of the kidney in one of four cases, and in the bowel in zero of three cases. In the three instances of bowel injury, free fluid was noted on ultrasonograms. Ultrasonography fared better in cases of splenic laceration, permitting detection in nine of 14 cases. The emergent ultrasonogram may be used to detect free fluid in the abdomen of the acutely traumatized patient. However, sonography is limited in detecting free fluid in the pelvis using the present technique and does not allow visualization of organ injury. Limitations of this examination should be recognized for appropriate triage of the acutely traumatized patient.

Cricothyrotomy: a 5-year experience at one institution.

We describe the prevalence, primary indications and immediate complications of emergency cricothyrotomy (cric) techniques, in a single institutions Emergency Department (ED) and associated air-medical transport service. This is a retrospective review at an academic, level-one trauma center with an annual ED census of 65,000 and an associated air-medical transport service (AMTS). All patients undergoing cric in the field or in the ED between July 1995 and June 2000 were included. Expert reviewers from Emergency Medicine, Trauma Surgery and the AMTS prospectively defined the complication criteria. All charts with a possible complication underwent a blinded evaluation by reviewers representing each of the three clinical services. Descriptive statistics were used to summarize the data. Fifty crics were performed over 5 years. Seventy-six percent of crics were performed in trauma patients. The prevalence of cric in patients requiring airway management in the ED was 1.1% (95% CI, 0.7-1.6) and 10.9% (95% CI, 6.9-16.1) in the field by the AMTS. The prevalence of complications was 14% (95% CI, 4-32.6) in ED patients and 54.5% (95% CI, 32-75.6) for prehospital patients. The overall inter-rater agreement for complication rate was excellent (kappa =.87). Overall, 77% of crics were performed using the rapid four-step technique (RFST). There were no reports of complications associated with the RFST when performed in the ED. Non-RFST crics in the ED had an associated complication rate of 25% (95% CI, 2.8-60). Emergency cricothyrotomy was performed in approximately 1% of all emergency airway cases in the ED and at a higher rate by the AMTS. The most frequent indications were trauma related. Additionally, the RFST was the most commonly used technique for cric at this institution. The complication rate of cric was significantly higher in the prehospital environment than in the ED.

Predicting the Need to Pack Early for Severe Intra-abdominal Hemorrhage

OBJECTIVE To determine if the decision to pack for hemorrhage could be refined. MATERIALS AND METHODS Seventy consecutive trauma patients for whom packing was used to control hemorrhage were studied. The patients had liver injuries, abdominal vascular injuries, and bleeding retroperitoneal hematomas. Preoperative variables were analyzed and survivors compared with nonsurvivors. RESULTS Packing controlled hemorrhage in 37 (53%) patients. Significant differences (p < 0.05) between survivors and nonsurvivors were Injury Severity Score (29 vs. 38), initial pH (7.3 vs. 7.1), platelet count (229,000 vs. 179,000/mm3), prothrombin time (14 vs. 22 seconds), partial thromboplastin time (42 vs. 69 seconds), and duration of hypotension (50 vs. 90 minutes). Nonsurvivors received 20 units of packed red blood cells before packing compared to 13 units for survivors. CONCLUSION Patients who suffer severe injury, hypothermia, refractory hypotension, coagulopathy, and acidosis need early packing if they are to survive. Failure to control hemorrhage is related to severity of injury and delay in the use of pack tamponade. A specific protocol that mandates packing when parameters reach a critical limit should be considered.

Hypertonic saline (7.5%) versus mannitol: A comparison for treatment of acute head injuries

Hypertonic saline (7.5% NaCl = HS) was compared with 20% mannitol (MAN), for the treatment of increased intracranial pressure (ICP), in a large animal model of head injury. Sheep were instrumented for hemodynamic and ICP monitoring and fluid administration. Elevated ICP (20-25 mm Hg) was produced by inflating an epidural balloon for 1 hour. Animals were then given a bolus of 250 mL of either HS (n = 7) or MAN (n = 7) and monitored for 2 hours. No significant differences in hemodynamic variables were noted between groups. The ICP decreased to the same degree in both groups during the 2 hours of observation (HS = 11 +/- 3.8 mm Hg; MAN = 8 +/- 2 mm Hg). Brain water contents were also similar (HS = 3.68 +/- 0.09 mL H2O/g dry wt; MAN = 3.83 +/- 0.08 mL H2O/g dry wt). The 7.5% NaCl was equally effective in treating elevated ICP caused by a space-occupying lesion when compared with 20% mannitol. Hypertonic saline has the additional benefit of rapid cardiovascular resuscitation of associated hemorrhagic shock with small-volume infusion.

A stepwise logistic regression analysis of factors affecting morbidity and mortality after thoracic trauma: Effect of epidural analgesia

Rib fractures and other chest wall injuries can lead to weak ventilation, atelectasis, and even death. Whereas such injuries in young patients are usually well tolerated, relatively minor chest wall trauma can be serious in elderly patients. Epidural analgesia, by improving pain control and ventilatory function, might improve morbidity and mortality rates compared to other forms of analgesia. Stepwise logistic regression was used to compare thoracic trauma patients more than 60 years of age treated with either epidural or parenteral (IV/IM) analgesia. In spite of more severe thoracic trauma in epidural patients as measured by the Abbreviated Injury Score for the chest (epidural = 3.3 +/- 0.1, IV/IM = 2.8 +/- 0.1; p less than 0.05) the use of epidural analgesia was an independent predictor of both decreased mortality (p = 0.0035) and a decreased incidence of pulmonary complications (p = 0.0088). Epidural analgesia has a positive effect on outcome in elderly trauma victims with chest wall injury and is useful in high-risk patients. Increased costs associated with epidural analgesia are minimal and are justified by improvements in outcome.

Hypertonic Saline Resuscitation of Head Injury: Effects on Cerebral Water Content

UNLABELLED Ideal resuscitation would simultaneously replete intravascular volume and minimize cerebral edema. We assessed the effects of hypertonic saline (HS) shock resuscitation on cerebral edema after head injury. Rats were subjected to hemorrhagic shock (40 mm Hg for 1 hour) in the presence or absence of mechanical brain injury, followed by 1 hour of resuscitation with either hypertonic saline (6.5%) or lactated Ringers (LR). After resuscitation, animals were sacrificed and brain water contents determined. RESULTS Less HS than LR was needed for resuscitation both in animals without brain injury (7 +/- 2 ml/kg vs. 97 +/- 16 ml/kg; p less than 0.0003) and with brain injury (10 +/- 1 ml/kg vs. 68 +/- 6 ml/kg; p less than 0.0001). Brain water content (ml H2O/gm dry wt) after HS resuscitation was decreased compared to LR resuscitation in animals without brain injury (3.36 +/- 0.12 vs. 3.74 +/- 0.08; p less than 0.025) and in the uninjured hemisphere of head-injured animals (3.29 +/- 0.11 vs. 3.78 +/- 0.09; p less than 0.025). Brain water content was increased in injured brain in both resuscitation groups, but the increase was the same (HS 4.10 +/- 0.13; LR 4.25 +/- 0.17; p greater than 0.05). CONCLUSIONS HS resuscitation of hemorrhagic shock decreases brain water content in uninjured but not injured brain. HS may be useful in resuscitation of combined hemorrhagic shock and head injury.

Identifying Children at Very Low Risk of Clinically Important Blunt Abdominal Injuries

STUDY OBJECTIVE We derive a prediction rule to identify children at very low risk for intra-abdominal injuries undergoing acute intervention and for whom computed tomography (CT) could be obviated. METHODS We prospectively enrolled children with blunt torso trauma in 20 emergency departments. We used binary recursive partitioning to create a prediction rule to identify children at very low risk of intra-abdominal injuries undergoing acute intervention (therapeutic laparotomy, angiographic embolization, blood transfusion for abdominal hemorrhage, or intravenous fluid for ≥2 nights for pancreatic/gastrointestinal injuries). We considered only historical and physical examination variables with acceptable interrater reliability. RESULTS We enrolled 12,044 children with a median age of 11.1 years (interquartile range 5.8, 15.1 years). Of the 761 (6.3%) children with intra-abdominal injuries, 203 (26.7%) received acute interventions. The prediction rule consisted of (in descending order of importance) no evidence of abdominal wall trauma or seat belt sign, Glasgow Coma Scale score greater than 13, no abdominal tenderness, no evidence of thoracic wall trauma, no complaints of abdominal pain, no decreased breath sounds, and no vomiting. The rule had a negative predictive value of 5,028 of 5,034 (99.9%; 95% confidence interval [CI] 99.7% to 100%), sensitivity of 197 of 203 (97%; 95% CI 94% to 99%), specificity of 5,028 of 11,841 (42.5%; 95% CI 41.6% to 43.4%), and negative likelihood ratio of 0.07 (95% CI 0.03 to 0.15). CONCLUSION A prediction rule consisting of 7 patient history and physical examination findings, and without laboratory or ultrasonographic information, identifies children with blunt torso trauma who are at very low risk for intra-abdominal injury undergoing acute intervention. These findings require external validation before implementation.