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Background: In critical injury, the occurrence of increased oxidative stress or a reduced antioxidant status has been observed. The purpose of this study was to correlate the degree of oxidative stress, by measuring the oxidation-reduction potential (ORP) of plasma in the critically injured, with injury severity and serum amyloid A (SAA) levels., Methods: A total of 140 subjects were included in this retrospective study comprising 3 groups: healthy volunteers (N = 21), mild to moderate trauma (ISS < 16, N = 41), and severe trauma (ISS >or= 16, N = 78). For the trauma groups, plasma was collected on an almost daily basis during the course of hospitalization. ORP analysis was performed using a microelectrode, and ORP maxima were recorded for the trauma groups. SAA, a sensitive marker of inflammation in critical injury, was measured by liquid chromatography/mass spectrometry., Results: ORP maxima were reached on day 3 (+/- 0.4 SEM) and day 5 (+/- 0.5 SEM) for the ISS < 16 and ISS >or= 16 groups, respectively. ORP maxima were significantly higher in the ISS < 16 (-14.5 mV +/- 2.5 SEM) and ISS >or= 16 groups (-1.1 mV +/- 2.3 SEM) compared to controls (-34.2 mV +/- 2.6 SEM). Also, ORP maxima were significantly different between the trauma groups. SAA was significantly elevated in the ISS >or= 16 group on the ORP maxima day compared to controls and the ISS < 16 group., Conclusion: The results suggest the presence of an oxidative environment in the plasma of the critically injured as measured by ORP. More importantly, ORP can differentiate the degree of oxidative stress based on the severity of the trauma and degree of inflammation.

Background: Although postinjury multiple organ failure (MOF) is a well-described phenomenon in adults, the incidence of this syndrome in children is unknown. The purpose of this study was to describe the incidence, course, and severity of pediatric postinjury MOF. We hypothesized that the incidence and severity of postinjury MOF in children would be less when compared with adults., Methods: Patients were retrospectively identified from the trauma registry of a regional pediatric trauma center and an adult Level I trauma center with pediatric commitment for a 3-year period. All trauma patients less than 16 years old who survived for longer than 24 hours and had an Injury Severity Score > 15 were eligible. An accepted MOF score was used. Categorical variables were compared by chi2 and continuous variables by t test. A value of p< 0.05 was considered statistically significant., Results: Of 534 patients identified, 334 (63%) were admitted for evaluation of isolated head injury and excluded from further analysis. The rate of postinjury MOF in children was found to be only 3%, with a low (17%) mortality when compared with historical adult data (50%)., Conclusion: The incidence of postinjury MOF in the child is less than in the adult, given equivalent injury severity. These observations solidify the contention that postinjury MOF is rare in children, and is less severe when it occurs. Delineating the mechanism(s) whereby children are protected from postinjury MOF may provide insight into the development of strategies to prevent MOF in other age groups as well as various disease states.

Background: The abdominal compartment syndrome (ACS) is a recognized complication of damage control surgery (DCS). The purposes of this study were to (1) determine the effect of ACS on outcome after DCS, (2) identify patients at high risk for the development of ACS, and (3) determine whether ACS can be prevented by preemptive intravenous bag closure during DCS., Methods: Patients requiring postinjury DCS at our institution from January 1996 to June 2000 were divided into groups depending on whether or not they developed ACS. ACS was defined as an intra-abdominal pressure (IAP) greater than 20 mm Hg in association with increased airway pressure or impaired renal function., Results: ACS developed in 36% of the 77 patients who underwent DCS with a mean IAP prior to decompression of 26 +/- 1 mm Hg. The ACS versus non-ACS groups were not significantly different in patient demographics, Injury Severity Score, emergency department vital signs, or intensive care unit admission indices (blood pressure, temperature, base deficit, cardiac index, lactate, international normalized ratio, partial thromboplastin time, and 24-hour fluid). The initial peak airway pressure after DCS was higher in those patients who went on to develop ACS. The development of ACS after DCS was associated with increased ICU stays, days of ventilation, complications, multiorgan failure, and mortality., Conclusions: ACS after postinjury DCS worsens outcome. With the exception of early elevation in peak airway pressure, we could not identify patients at higher risk for ACS; moreover, preemptive abdominal bag closure during initial DCS did not prevent this highly morbid complication.

Hypothesis: Abdominal compartment syndrome (ACS) is a morbid complication of damage-control laparotomy. Moreover, the technique of abdominal closure influences the frequency of ACS., Design: Retrospective cohort study., Setting: Urban level I trauma center., Patients: We studied 52 patients with trauma who required damage-control laparotomy during the 5 years ending December 31, 1999, and who survived longer than 48 hours., Main Outcome Measures: Abdominal compartment syndrome, acute respiratory distress syndrome (ARDS), and multiple organ failure (MOF)., Results: Mean (+/- SD) age was 33 +/- 2 years; 38 (73%) were male. Mechanism of injury was blunt in 29 patients (56%), and mean (+/- SD) Injury Severity Score was 28 +/- 2. Development of ARDS and/or MOF was seen in 23 patients (44%); ARDS and MOF increased mortality from 12% (3/26) to 42% (11/26). Abdominal compartment syndrome was a common complication (17/52), and was associated with an increase in ARDS and/or MOF (12 patients [71%] vs 11 patients [31%] without ACS; P =.02, chi(2) test) and death (6 [35%] vs 8 patients [23%] without ACS). Primary fascial closure (n = 10) at the initial laparotomy was associated with ACS in 8 (80%) (P =.001, chi(2) test) and ARDS and/or MOF in 9 (90%) (P =.01, chi(2) test); skin closure (n = 25), with ACS in 6 (24%) and ARDS/MOF in 9 (36%); and Bogotá bag closure (n = 17), with ACS in 3 (18%) and ARDS/MOF in 8 (47%)., Conclusions: Damage-control laparotomy is associated with frequent complications. In particular, ACS is a serious complication that increases ARDS and/or MOF and mortality. Avoiding primary fascial closure at the initial laparotomy can minimize the risk for ACS.

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.

Introduction: Prone ventilation improves oxygenation in selected patients with acute respiratory distress syndrome (ARDS). However, prone positioning of critically ill patients with multiple invasive lines and tubes is potentially dangerous. Trauma patients, in particular, may require special consideration because of skeletal fixation devices or prior operative procedures. Our objective was to critically evaluate our experience with prone positioning in patients with severe postinjury ARDS., Methods: Injured patients admitted to our Level I trauma center who developed ARDS were prospectively identified. Serial lung injury severity and pulmonary mechanical data, as well as complications of prone ventilation were recorded., Results: During the 12-month period ending August of 1998, nine patients with postinjury ARDS were treated with prone ventilation because of hypoxemia refractory to other ventilatory strategies. All patients suffered blunt trauma. Their mean age was 29 +/- 4.5 years; seven patients were men. The average Injury Severity Score was 26 +/- 5; and, at the time of prone positioning, the mean Lung Injury Score was 3.5. The mean PaO2/FIO2 ratio increased from 75 +/- 7 to 147 +/- 27 with prone ventilation (p < 0.05, paired t test); and in six patients, the FIO2 could be decreased. Four major complications occurred (44%). One patient experienced a midline abdominal wound dehiscence. Severe facial or upper chest wall pressure necrosis developed in two patients, despite extensive padding and careful attention to skin care. The fourth patient sustained a cardiac arrest immediately after prone positioning., Conclusion: Prone ventilation in postinjury patients with ARDS may improve oxygenation but has the potential for significant complications. Careful consideration is required before prone positioning in this subset of patients.