David A. Partrick

The positive predictive value of rib fractures as an indicator of nonaccidental trauma in children

BACKGROUND Rib fractures have a strong association with nonaccidental trauma (NAT) and severe trauma. The purposes of this study were to evaluate rib fractures in children to determine (1) the positive predictive value of a rib fracture in defining NAT and (2) the frequency of rib fractures as the only skeletal manifestation of NAT. METHODS We reviewed the medical records and imaging of all children with rib fractures over a 6-year period. NAT was determined by the Child Advocacy and Protection team. RESULTS In children younger than 3 years of age, the positive predictive value (PPV) of a rib fracture as an indicator of NAT was 95%. The positive predictive value increased to 100% once historical and clinical circumstance excluded all other causes for rib fractures. CONCLUSION In this study, rib fracture(s) were the only skeletal manifestation of NAT in 29% of the children.

The inflammatory profile of interleukin-6, interleukin-8, and soluble intercellular adhesion molecule-1 in postinjury multiple organ failure

Background Interleukin-6 (IL-6), interleukin-8 (IL-8), and adhesion molecules have been implicated as mediators in neutrophil (PMN) and endothelial cell (EC) interactions leading to postinjury multiple organ failure (MOF). Our hypothesis was that circulating levels of IL-6, IL-8, and soluble intercellular adhesion molecule-1 (s-ICAM-1) would discriminate patients at risk for postinjury MOF. Methods Serial plasma levels of IL-6, IL-8, and sICAM-1 were measured in 27 high-risk trauma patients. Results The IL-6 and IL-8 levels were significantly elevated in MOF patients compared with non-MOF patients at 12 and 36 hours postinjury. The IL-6 level was also elevated at 84 and 132 hours, and IL-8 at 84 hours. The sICAM-1 level did not become elevated in MOF patients until 132 hours postinjury. Conclusion Interleukin-6 and IL-8 are elevated early after trauma and discriminate patients who will develop MOF. Late elevation of sICAM-1 likely results from PMN cytotoxicity leading to EC injury or inflammation.

Resuscitation with a blood substitute abrogates pathologic postinjury neutrophil cytotoxic function

BACKGROUND Resuscitation with oxygen-carrying fluids is critically important in the patient with hemorrhagic shock caused by trauma. However, it is clear that a number of biologic mediators present in stored blood (packed red blood cells [PRBCs]) have the potential to exacerbate early postinjury hyperinflammation and multiple organ failure through priming of circulating neutrophils (PMNs). PolyHeme (Northfield Laboratories, Evanston, IL), a hemoglobin-based substitute that is free of priming agents, provides an alternative. We hypothesized that PMN priming would be attenuated in patients resuscitated with PolyHeme in lieu of stored blood. METHODS Injured patients requiring urgent transfusion were given either PolyHeme (up to 20 units) or PRBCs. Early postinjury PMN priming was measured via beta-2 integrin expression, superoxide production, and elastase release. RESULTS Treatment groups were comparable with respect to extent of injury and early physiologic compromise. PMNs from patients resuscitated with PRBCs showed priming in the early postinjury period by all three measures. No such priming was evident in patients resuscitated with PolyHeme. CONCLUSION The use of a blood substitute in the early postinjury period avoids PMN priming and may thereby provide an avenue to decrease the incidence or severity of postinjury multiple organ failure.

Ultrasound is an effective triage tool to evaluate blunt abdominal trauma in the pediatric population

BACKGROUND Although computed tomography has been considered the diagnostic modality of choice for pediatric patients with blunt abdominal trauma (BAT), it is costly, time-consuming, requires sedation, and may be associated with complications in young children. Abdominal ultrasonography (US) is a promising modality in the evaluation of BAT that is quick, noninvasive, repeatable, and cost-effective. We hypothesized that emergency department US, performed by trauma surgeons, is a useful triage tool for pediatric BAT that reduces the need for computed tomography. METHODS The 230 children (<18 years old) with suspected BAT were initially evaluated with US in the emergency department by surgeons. Subsequent computed tomographic scan or exploratory laparotomy was performed as indicated by the key clinical pathway. RESULTS Twelve children (5.2%) had documented intra-abdominal injuries. All five injured children with significant intraperitoneal fluid were identified by US. Of the seven patients who had intra-abdominal injury not detected by US, six sustained solid organ injuries that were managed nonoperatively. Extrapolated reductions in hospital charges due to the decreased number of computed tomographic scans total

Port-site recurrence after thoracoscopic resection of pulmonary metastasis owing to osteogenic sarcoma

130,000. CONCLUSIONS Using US as a triage tool may dramatically reduce the cost of pediatric BAT evaluation while being able to quickly identify significant intraperitoneal fluid that requires further evaluation and possible laparotomy.

Acute hypoxemia in humans enhances the neutrophil inflammatory response

Video-assisted thoracic surgery (VATS) is being used increasingly to evaluate and treat intrathoracic pathology. Port-site seeding is a rare but feared complication when minimally invasive surgical techniques are used in the evaluation and treatment of malignancies. The authors report a case of port-site seeding after thoracoscopic resection of pulmonary metastasis from an osteogenic sarcoma.

Failure of resolution of portal fibrosis during omega-3 fatty acid lipid emulsion therapy in two patients with irreversible intestinal failure.

The neutrophil (PMN) is regarded as a key component in the hyperinflammatory response known as the systemic inflammatory response syndrome. Acute respiratory distress syndrome (ARDS) and subsequent multiple organ failure (MOF) are related to the severity of this hyperinflammation. ICU patients who are at highest risk of developing MOF may have acute hypoxic events that complicate their hospital course. This study was undertaken to evaluate the effects of acute hypoxia and subsequent hypoxemia on circulating PMNs in human volunteers. Healthy subjects were exposed to a changing 02/N2 mixture until their 02 saturation (Sa02) reached a level of 68% saturation. These subjects were then exposed to room air and then returned to their baseline Sa02. PMNs were isolated from pre- and post-hypoxemic arterial blood samples and were then either stimulated with N-formyl-methionyl-leucyl-phenylalanine (fMLP) or PMA alone, or they were primed with L-&agr;-phosphatidylcholine, &bgr;-acetyl-&ggr;-O-alkyl (PAF) followed by fMLP activation. Reactive oxygen species generation as measured by superoxide anion production was enhanced in primed PMNs after hypoxemia. Protease degranulation as measured by elastase release was enhanced in both quiescent PMNs and primed PMNs after fMLP activation following the hypoxemic event. Adhesion molecule upregulation as measured by CD11b/CD18, however, was not significantly changed after hypoxemia. Apoptosis of quiescent PMNs was delayed after the hypoxemic event. TNF&agr;, IL-1, IL-6, and IL-8 cytokine levels were unchanged following hypoxemia. These results indicate that relevant acute hypoxemic events observed in the clinical setting enhance several PMN cytotoxic functions and suggest that a transient hypoxemic insult may promote hyperinflammation.

Nonoperative management of solid organ injuries in children results in decreased blood utilization

Parenteral omega-3 fatty acid lipid emulsions have been evaluated for their potential role in reversing intestinal failure-associated liver disease. We report our experience using Omegaven in 2 patients with irreversible intestinal failure and intestinal failure-associated liver disease. Despite biochemical and histologic improvement in cholestasis, both patients had persisting, significant portal fibrosis on liver biopsy.

REDUCED PAF-ACETYLHYDROLASE ACTIVITY IS ASSOCIATED WITH POSTINJURY MULTIPLE ORGAN FAILURE

BACKGROUND The administration of blood products to injured children has been recognized as a potential risk of nonoperative management. The purpose of this study was to evaluate blood utilization in the management of solid organ injuries in pediatric blunt abdominal trauma victims. METHODS One hundred sixty-one children (< or =16 years old) with solid organ injuries over an 8-year study period (1990 through 1997) were identified from the trauma registries at 2 urban regional trauma centers. RESULTS Mean age of the study patients was 7.9+/-0.4 years, 95 (59%) were boys, and their mean injury severity score (ISS) was 17.8+/-1.2. Patients were divided into 4-year study cohorts (1990 through 1993 and 1994 through 1997) to examine changes in operative management and blood utilization. For each time period examined, those treated nonoperatively received fewer blood transfusions (46% v 9% and 44% v 13%, P<.05 by Fishers Exact test), and the hospital length of stay was shorter (12.3+/-2.1 v 5.0+/-0.7 and 7.8+/-1.9 v 4.2+/-0.4 days, P<.0001 by analysis of variance/Scheffes) compared with the laparotomy cohort. CONCLUSIONS The appropriate nonoperative management of injured children actually reduces the risks of receiving blood transfusion and decreases the length of hospital stay compared with aggressive operative intervention. Blood transfusion should be reserved only for those injured children with solid organ injuries who are hemodynamically unstable.

Release of anti-inflammatory mediators after major torso trauma correlates with the development of postinjury multiple organ failure.

Our basic laboratory work has identified the postischemic gut as a source of platelet-activating factor (PAF), which primes circulating neutrophils for the production of reactive oxygen metabolites (ROMs) leading to distant organ injury. Circulating PAF-acetylhydrolase (PAF-AH) hydrolyzes PAF to lyso-PAF. Recently, ROMs have been shown to rapidly and irreversibly inactivate human PAF-AH. Consequently, our study hypothesis was that reduced levels of PAF-AH in severely injured patients would be associated with the development of multiple organ failure (MOF). Over a 16 mo period, 26 patients at known risk for MOF (Injury Severity Score (ISS) ≥25 or an ISS >15 with ≥6 U of blood transfused within the first 6 h) had blood sampled on postinjury days 0, 1, 2, 3, and 5. PAF-AH activity was assessed by measuring the percentage of 3H-labeled PAF hydrolyzed. MOF was defined by a standard score. The mean age of the 26 study patients was 34 ± 2 yr; 19 (73%) were male. The injury mechanism was blunt in 18 (69%), and the mean ISS was 31 ± 2. Eight patients (31 %) developed MOF. In the MOF patients, plasma PAF-AH activity was significantly lower on the day of injury and remained depressed throughout the ensuing 5 days compared with the non-MOF patients. Reduced PAF-AH activity is associated with the development of postinjury MOF. With the recent molecular cloning of human plasma PAF-AH, repleting this circulating, anti-inflammatory enzyme may represent useful therapy for these high risk patients.