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Background Patients with minimal head injury (MHI) and a cranial computed axial tomography (CAT) scan positive for the presence of intracranial injury routinely undergo a repeat CAT scan within 24 hours after injury. The value of this repeat cranial CAT scan is unclear in those patients who are neurologically normal or improving. Methods A retrospective analysis of all adult patients admitted to a level-1 trauma center with MHI and a positive cranial CAT scan during a 32-month period was performed. The need for neurosurgical intervention after repeat CAT scan in patients with a persistently normal or improved neurological examination was recorded. Results One hundred fifty-one patients had a persistently normal or improved neurological examination, but none of these patients required neurosurgical intervention after the repeat cranial CAT scan. Conclusions A persistently normal or improving neurological examination in a patient with MHI appears to exclude the need for neurosurgical intervention and thus a repeat cranial CAT scan.

After trauma/hemorrhagic shock (T/HS), inflammatory products exit the gut via mesenteric lymph. These products can prime neutrophils (PMN) and predispose to lung injury. Female gender and the proestrous state (PE) may confer protection against lung injury after T/HS. We therefore studied the dependence of T/HS-induced PMN priming on gender and stage of estrous.T/HS was induced in male (M) and proestrous female (F) rats by laparotomy plus hemorrhagic shock (30 mm Hg, 90 min) followed by reinfusion of shed blood. Six hours later rats were sacrificed and plasma was obtained. Control male rat PMN were primed 5 min in buffer or in the plasma of M-T/HS or F-T/HS rats (n = 4-6/group). PMN were then assayed using DHR for respiratory burst (RB) initiated by sequential MIP-2 and PAF stimulation (MIP/PAF). Because MIP and PAF mobilize cell calcium ([Ca(2+)](i)) in a step crucial for RB initiation, we also assayed PMN [Ca(2+)](i) responses to MIP/PAF.M-T/HS plasma primed PMN RB (208 +/- 8 [SEM] U/sec versus buffer 51 +/- 12 U/sec, p0.01, ANOVA/Tukey's). F-T/HS plasma did not (87 +/- 20 U/sec, NS). PMN basal [Ca(2+)](i) was increased by pre-incubation in both M-T/HS and F-T/HS plasma (183 +/- 26 and 225 +/- 20 nM, p0.02, p0.01 compared to buffer [80 +/- 3 nM]). Peak PMN [Ca(2+)](i) response to MIP/PAF was 159 +/- 2 nM without priming. Priming PMN in either M-T/HS or F-T/HS plasma increased peak [Ca(2+)](i) responses to MIP/PAF to 274 +/- 35 (p0.04) and 330 +/- 24 nM (p0.02), but the effects of M-T/HS and F-T/HS plasma on [Ca(2+)](i) mobilization were indistinguishable.Plasma from male rats subjected to T/HS primes PMN respiratory burst, but plasma from proestrous females subjected to T/HS does not. In contrast, the male and proestrous female plasma primed PMN [Ca(2+)](i) mobilization by MIP/PAF equally. The decrease in pathologic PMN activation seen after T/HS in proestrous female rats depends on soluble mediators present in plasma. The decreased PMN RB seen after T/HS in proestrous females is mediated by calcium-independent pathways.

There is evidence suggesting that the ischemic gut is a major source of factors that lead to neutrophil activation, and that neutrophil activation can be reduced by hypertonic saline resuscitation. Thus, we tested whether trauma-hemorrhagic shock-induced neutrophil activation can be reduced by hypertonic saline resuscitation, as well as whether hypertonic saline reduces the ability of mesenteric lymph from shocked animals to activate neutrophils. Male Sprague-Dawley rats subjected to trauma (laparotomy), plus 90 min of shock [mean arterial pressure (MAP) MAP = 30 mmHg] or sham shock were resuscitated with Ringer's lactate or 7.5% hypertonic saline at an equivalent sodium load. Whole blood samples were collected before shock as well as at 1 and 2 h after the end of the shock period for neutrophil CD11b and CD18 expression measurements. In a second set of experiments, mesenteric lymph samples collected from rats subjected to trauma plus hemorrhagic shock (T/HS) or trauma plus sham-shock (T/SS) and resuscitated with Ringer's lactate or hypertonic saline were tested for their ability to modulate PMN CD11b, CD18, or L-selectin expression, as well as prime PMN for an augmented respiratory burst. To avoid confounding results due to interspecies differences, while at the same time looking at potential human responses, both naive rat and human PMN were tested. Both CD11b and CD18 expression were increased in PMN harvested from rats subjected to T/HS and resuscitated with Ringer's lactate solution, but not in T/HS rats resuscitated with hypertonic saline. These results indicate that PMN activation is increased to a greater extent in Ringer's lactate-resuscitated than hypertonic saline-resuscitated animals. Likewise, mesenteric lymph from the T/HS rats resuscitated with Ringer's lactate increased naive rat and human PMN CD11b and CD18 expression to a greater extent than did T/HS lymph from the hypertonic saline-treated rats. Additionally, T/HS lymph from the Ringer's lactate- but not the hypertonic saline-treated rats induced PMN L-selectin shedding. Lastly, T/HS lymph from the Ringer's lactate-treated rats induced the greatest PMN respiratory burst. These results indicate that resuscitation from T/HS with hypertonic saline is associated with less PMN activation than resuscitation with Ringer's lactate, and that factors produced or released by the postischemic intestine and carried in the mesenteric lymph contribute to neutrophil activation after an episode of T/HS.

The literature supports the concept that autopsies are useful in uncovering missed injuries or undiagnosed conditions that contribute to death after injury, especially late deaths that take place in the intensive care unit. Review of autopsies are also used as part of the trauma quality assurance (QA) process, and autopsy rates are queried by the American College of Surgeons Committee on Trauma in their reviews. Our hypothesis was that autopsies add little useful clinical or diagnostic information compared with QA peer review analysis in a mature trauma program.Autopsies for all mortalities at a Level I trauma center between January 1998 and October 1999 were reviewed. The autopsies were reviewed in a "blinded" fashion such that each review occurred before examination of the chart, the trauma registry, and the findings of the trauma QA peer review. Findings from all sources were compared and examined for Goldman type errors (I-IV).Two hundred sixty-three mortalities were identified, with 216 autopsies reviewed. One hundred two (39%) mortalities were considered dead on arrival to the trauma center by QA review, with no management errors identified (group 1) (Immediate Death group). Sixty-one patients survived more than 48 hours after injury (group 2). One hundred sixty-one (61%) patients were admitted to the hospital. Ninety-nine patients died within 48 hours (Early Death group) and 62 died between 2 and 143 days (Late Death group). There were no Goldman type I errors (major diagnostic discrepancies that might have influenced mortality) identified in either group. Autopsy data did uncover one potentially technical error in a death that was considered nonpreventable on peer review analysis.We conclude that autopsy information for either group appeared to add little useful information to the QA peer review of deaths in a mature trauma program. This was true even in cases where the final QA determination was held pending the results of the autopsy. Autopsy rates may not be a useful parameter in evaluating a trauma QA program.

BACKGROUND After trauma and hemorrhagic shock (T/HS), mesenteric lymph (ML) activates polymorphonuclear neutrophils (PMNs), injures endothelial cells (ECs), and predisposes to lung injury. The involved mediators, however, are unknown. We studied the ability of aqueous (AQ) and lipid (LIP) extracts of rat T/HS ML to activate PMNs and injure ECs. METHODS ML was collected from male rats undergoing trauma (laparotomy) plus hemorrhagic shock (30 mm Hg, 90 minutes) or sham shock. AQ and LIP ML fractions were separated using the Bligh-Dyer technique. Human umbilical vein endothelial cells were incubated 18 hours in 5% LIP or AQ lymph fractions and viability was assessed using the MTT assay. Rat PMNs incubated 5 minutes with 3% LIP or AQ fractions were assessed for respiratory burst (RB) and cytosolic calcium ([Ca(2+)](i)) using dihydrorhodamine 123 and fura-2AM. Human PMN responses to AQ and LIP T/HS lymph were studied similarly. RESULTS EC incubated in AQ showed 19 +/- 4% viability as compared with 65 +/- 11% in LIP (p < 0.001). Whole lymph affected ECs comparably to AQ T/HS lymph. Rat PMN basal [Ca(2+)](i) increased after exposure to AQ but not LIP T/HS lymph extracts. AQ T/HS lymph primed [Ca(2+)](i) responses to macrophage inflammatory protein-2 and platelet-activating factor; neither LIP T/HS nor any trauma and sham shock lymph fraction caused PMN priming. Rat PMN RB was elevated after AQ T/HS lymph incubation when compared with buffer (610 +/- 122 U/s vs. 225 +/- 38 U/s, p = 0.01). Rat PMN incubation in LIP T/HS lymph caused minimal activation (289 +/- 28 U/s, p = NS). Conversely, human PMN showed [Ca(2+)](i) and RB priming by rat T/HS LIP and not AQ extracts. CONCLUSION T/HS mesenteric lymph contains multiple biologically active mediators. Both AQ and LIP extracts of T/HS lymph are toxic to human umbilical vein endothelial cells, with AQ more active than LIP. Only AQ T/HS lymph activates rat PMNs, although LIP rat lymph extract activates human PMNs. These findings demonstrate the complex nature of gut lymph-derived biologic factors as well as species-specific differences on PMN and EC physiology. Therapies directed at any one specific molecule or mediator are therefore unlikely to be successful.

Objective: To determine whether hemorrhagic shock-induced bone marrow failure is mediated by the gut through the production of toxic mesenteric lymph and whether shock-induced bone marrow failure could be prevented by division of the mesenteric lymphatics. Design: Prospective, controlled study. Setting: University surgical research laboratory. Subjects: Male Sprague-Dawley rats. Interventions: Rats were divided into five groups: unmanipulated controls (n = 12), hemorrhagic shock with laparotomy (n = 8), hemorrhagic shock with mesenteric lymph duct ligation (n = 10), sham shock with laparotomy (n = 6), and sham shock with mesenteric lymph duct ligation (n = 7). At either 3 or 6 hrs after resuscitation, bone marrow was obtained for determination of early (cobblestone forming cells) and late (granulocyte-macrophage colony forming unit and erythroid burst forming unit) hematopoietic progenitor cell growth. Parallel cultures were plated with plasma (1% and 2% v/v) from all groups to determine the effect of lymphatic ligation on hematopoiesis. Measurements and Main Results: Bone marrow cellularity, cobblestone forming cells, granulocyte-macrophage colony forming unit, and erythroid burst forming unit growth in rats subjected to hemorrhagic with lymph duct ligation were similar to those observed in sham-treated animals and significantly greater than in rats subjected to shock and laparotomy without lymphatic duct ligation. Plasma from rats subjected to shock without lymph ligation was inhibitory to hematopoietic progenitor cell growth. In contrast, this shock-induced inhibition was not observed with plasma obtained from shocked rats that underwent mesenteric lymph ligation. Conclusions: Hemorrhagic shock suppresses bone marrow hematopoiesis as measured by a decrease in early and late progenitor cell growth. This suppression appears mediated through mesenteric lymph as the effect is abrogated by mesenteric lymph duct ligation. These data clearly demonstrate a link between the gut and bone marrow failure after hemorrhagic shock.

Bone marrow (BM) dysfunction has been shown to occur in experimental animal models of hemorrhagic shock, hypoxia, soft tissue injury, and thermal injury. 1–5 Whether a similar alteration in BM function occurs in humans after injury is less clear and has been not well studied. Moore et al 6 showed that there was a marked rise in circulating granulocyte-macrophage colony-forming units (CFU-GM) in patients for up to 10 days after blunt torso trauma. Coincident with the release of immature progenitors into the periphery was the fact that peripheral mononuclear cells from trauma patients produced reduced levels of colony-stimulating activity in response to lipopolysaccharide compared with controls. The degree of BM failure also appeared to correlate with the degree of injury. Persistent anemia has long been documented in intensive care unit patients. 7 This anemia has been examined after thermal injury, 8 and most recently Iversen et al 9 reported a decrease in bone marrow erythroid burst-forming units (BFU-E) in patients after spinal cord injury. Successful hematopoiesis is a complex regulated process in which pluripotential stem cells proliferate and differentiate to generate all necessary mature blood cells. 10 The process of immune and red blood cell formation requires the interaction between BM progenitor and stem cells with their microenvironment, which includes BM stromal cells, extracellular matrix proteins, and other soluble factors. 11–13 BM stroma has previously been reported to influence hematopoiesis by the elaboration of regulatory cytokines, 14 as well as to regulate progenitor cell growth and differentiation through direct cell–cell contact. 15,16 Thus, BM stroma is central in both the maintenance and the regulation of hematopoiesis. Consequently, any disruption of BM hematopoiesis after injury is likely to be at least partly mediated through the interaction of BM stroma with hematopoietic progenitor cells. Trauma results in the migration of inflammatory cells to the site of injury, and a multitude of cytokines and chemokines have been documented to be secreted into both the local tissue environment and systemic circulation. 17–20 Many of these cytokines and wound fluids have been shown to have an effect on immune cells. For example, Hauser et al 21 showed that fluid surrounding the sites of fracture in trauma patients contained high levels of interleukin (IL)-6 and IL-8. Plasma obtained from rats subjected to hemorrhagic shock has been shown to inhibit CFU-GM formation from BM cells. 2 The hypothesis of these experiments is that plasma obtained from patients after severe injury would inhibit hematopoiesis in both red blood cell (as measured by BFU-E) and white blood cell (as measured by CFU-GM) lineages, and that this inhibition would be mediated through plasma’s interaction with the BM stroma.

G-protein coupled (GPC) chemoattractants are important neutrophil (PMN) activators in human shock and sepsis, acting in part by increasing cytosolic calcium ([Ca 2+ ] i ). Rats are widely used as laboratory models of shock and sepsis, but reports of [Ca 2+ ] i flux in circulating rat PMN are rare. Moreover, the [Ca 2+ ] i values reported often differ markedly from human systems. We developed study methods where basal [Ca 2+ ] i values in circulating rat PMN were comparable to human PMN, but rat PMN still mobilized calcium poorly after stimulation. Trauma (laparotomy) did not change rat PMN basal [Ca 2+ ] i , but induced brisk [Ca 2+ ] i responses to chemokine and lipid mediators that approximated human PMN responses. This was associated with marked loading of microsomal calcium stores. Formyl peptides still mobilized calcium less well in rat than human PMN. Normal rat PMN appear to circulate in a less mature or primed form than human PMN. A very limited injury rapidly converts rat PMN to a more activated phenotype. PMN thus activated act quite similar to human PMN in terms of GPC receptor-mediated calcium mobilization. Trauma enhances rat PMN responses to GPC agonists at least in part by loading cell calcium stores.

Background: Damage control laparotomy (DCL) with abdominal packing has become commonplace after major trauma, but the immune consequences of DCL are unknown. Methods: We collected 37 fluid samples from laparotomy pads (LPF) removed from 28 patients 1 hour to 7 days after DCL. Samples from eight patients who underwent serial packing were assayed for their mediator content and effects on neutrophil (PMN) function. Respiratory burst (RB) to N-formyl-methionyl-leucyl-phenylalanine and phorbol myristate acetate (PMA), as well as PMN calcium ([Ca 2+ ] i ) mobilization by GRO-a and platelet-activating factor were studied using dihydrorhodamine and fura-2-acetoxymethyl ester fluorescence. Brief exposure to 20% LPF (LPF20) modeled LPF acting on peritoneal PMNs and 2% LPF (LPF2) modeled the systemic effects on PMNs. Endotoxin (ETX), GRO-a, and leukotriene B4 were assayed by enzyme-linked immunosorbent assay. Data analysis was by analysis of variance with Dunn's comparisons or the Mann-Whitney test when indicated. Results: LPF increased N-formyl-methionyl-leucyl-phenylalanine-induced RB from 0.4 ± 0.1 x 10 3 counts per second (control) to 0.7 ± 0.1 (LPF2) to 1.3 ± 0.3 (LPF20) (p < 0.05), with LPF2 increasingly active at later times after injury. PMA-elicited RB was primed only by LPF2 from < 24 hours. Both LPF2 and LPF20 markedly suppressed GRO-a [Ca 2+ ] i flux. Suppression by LPF2 was maximal at < 24 hours, abating after 48 hours. Suppression of GRO-a response was dose dependent: 150 ± 8 nmol/L in control PMNs, 97 ± 19 after LPF2, and 59 ± 4 after LPF20 (all p < 0.05). [Ca 2+ ] i flux after 1 nmol/L platelet-activating factor was only suppressed (from 181 ± 14 nmol/L to 149 ± 15 nmol/L,p < 0.05) by LPF20. LPF contained ETX, GRO-a, and leukotriene B4 at 10- to 20-fold plasma concentration in trauma patients. Conclusion: DCL results in peritoneal ETX and mediator accumulation even when cultures are sterile. LPF exposure primes PMN RB elicited by nonreceptor- (PMA) or receptor-coupled agonists that resist receptor desensitization. Conversely, LPF suppresses PMN responses to agonists that undergo receptor desensitization at high mediator concentrations. PMN dysfunction in such circumstances probably reflects a concomitant priming of some cell functions (e.g., RB) and desensitization of other (receptor-dependent) functions after an exposure to concentrated mediators. Peritoneal mediator production after DCL may be ETX driven, and may contribute to systemic inflammatory response syndrome. DCL trades early hemostasis for later inflammation. This should be considered in planning management strategies.

BACKGROUND Trauma modulates polymorphonuclear neutrophil (PMN) function, predisposing to organ failure and infection. Many chemoattractants released by injury activate PMNs via G-protein-coupled (GPC) receptors, which elevate PMN cytosolic calcium ([Ca2+]i). Nonetheless, PMN GPC receptor function after injury is unstudied. METHODS PMNs from 11 major trauma patients (Injury Severity Score = 31 +/- 3, eight men and three women, age = 38 +/- 3) were obtained on days 1, 3, and 7 after injury. Nine developed organ failure and one died. PMNs were exposed to interleukin-8 (IL-8), growth regulated oncogene-alpha (GRO-alpha), and platelet-activating factor (PAF) to stimulate the CXCR1, CXCR2, and PAF receptors. [Ca2+]i flux measurements were used to quantify receptor responses. Receptor responses to individual as well as serial GPC agonists were studied over the week after injury and compared with the responses of PMNs from healthy volunteers (n = 10-23). Results were evaluated by one-way analysis of variance, and paired and unpaired t tests. RESULTS Responses to GRO-alpha and PAF were significantly depressed early after injury (p < 0.01). Responses to all agonists tested tended to be lowest on day 1, to peak on day 3, and to decrease again by day 7, but variations in response to GRO-alpha were the most marked (p < 0.03, analysis of variance). Whereas GRO-alpha primed IL-8 and IL-8 primed PAF in normal PMNs, GRO-alpha paradoxically suppressed IL-8 responses and IL-8 suppressed PAF responses in trauma PMNs. PAF priming of IL-8 responses was unaffected by injury. CONCLUSION Receptor responses to individual GPC agonists are suppressed early after trauma, but increase by day 3. Normal chemokine priming of PMN calcium mobilization is reversed by injury; priming by PAF is intact. PMN GPC responses depend on the sequence in which agonists are encountered. Injury appears to alter these interactions, thus priming some aspects of PMN function while simultaneously suppressing others.

Purpose: Chemotaxins from inflammatory sites prime or activate neutrophils (PMN) by using cytosolic calcium ([Ca 2+ ] i ) fluxes as second messengers. [Ca 2+ ] i can be mobilized rapidly by receptor-mediated entry or store-release, or more slowly by store-operated calcium influx (SOCI). We studied [Ca 2+ ] i mobilization by chemotaxins and how trauma impacts the calcium entry mechanisms used by chemotaxins. Methods: [Ca 2+ ] i flux was studied by spectrofluorometry. The contributions of early and late [Ca 2+ ] i currents to net calcium flux were compared after stimulation by more potent (fMLP, C5a, PAF) or less potent (IL-8, GRO-a, and LTB4) agonists. Store operated [Ca 2+ ] i mobilization was reflected by the ratio of area under the [Ca 2+ ] i efflux curve to peak [Ca 2+ ] i (efflux curve). PMN from trauma patients (ISS > 25) and pair-matched volunteer (n = 7 pairs) were then primed and stimulated with thapsigargin to compare cell calcium stores and SOCI. Results: Late [Ca 2+ ] i mobilization made more important contributions to fMLP, PAF, and C5a signals than to IL-8, GRO-a, or LTB4 (p < 0.01 all comparisons). Calcium stores and store release were only marginally lower after injury (p = not significant), but trauma PMN showed far higher [Ca 2+ ] i influx after thapsigargin (p = 0.007), and greater net SOCI (p = 0.034). Conclusions: SOCI may play an important role in PMN activation, and trauma increases PMN SOCI. Prolonged elevations of [Ca 2+ ] i due to enhanced SOCI may alter stimulus-response coupling to chemotaxins and contribute to PMN dysfunction after injury.

Neutrophil (PMN) priming and subsequent responses to the IL-8 presented on pulmonary endothelial surfaces may be crucial determinants of the development of adult respiratory distress syndrome after injury. Elevated plasma ELR+ C-X-C chemokine (CXC) levels might contribute to PMN priming after trauma, but the role of CXCs in priming circulating PMNs is unstudied. We evaluated the interactions of IL-8 and GRO-alpha in priming human PMN calcium fluxes [Ca2+]i within circulatory environments. At physiologic concentrations, GRO-alpha primes PMN for IL-8 mediated [Ca2+]i mobilization, whereas IL-8 abolishes GRO-alpha responses. Repeated GRO-alpha exposures further enhance IL-8 responses. PMN priming for IL-8 responses in normal plasma was CXCR2 dependent. CXCR2 was more responsive than CXCR1 to low levels of IL-8, together suggesting that CXCR2 is the important CXC receptor at circulating (i.e., low) agonist concentrations. CXCR1 stimulation down-regulated CXCR2 surface expression, whereas CXCR2 stimulation upregulated CXCR1 expression. GRO-alpha/ CXCR2 signaling enhanced post-receptor IL-8 initiated PMN [Ca2+]i influx as well as efflux. Sufficient stimulation of the CXCR1 terminated this cooperative relationship by downregulating surface expression of CXCR2. This study is the first to report that at physiologic concentrations, C-X-C chemokines can act on circulating human PMNs as an integrated system where CXCR2 agonists, rather than cross-desensitizing CXCR1, act to enhance signaling of IL-8 at CXCR1 both by receptor and post-receptor mechanisms. Such CXCR2 mediated priming of CXCR1/ IL-8 interaction may enhance PMN attack on the lung after injury.

That granulocyte-macrophage colony-stimulating factor (GM-CSF) and its receptor modulate the suppression of apoptosis (Ao) of normal neutrophils incubated in the plasma of patients with postraumatic acute respiratory distress syndrome (ARDS).Experimental study using cultured human neutrophils.University hospital, level I trauma center.Plasma was obtained from 14 patients with early, fulminant posttraumatic ARDS (mean Injury Severity Score, 22). All samples were drawn within 24 hours after injury. Plasma was also taken from up to 21 healthy control subjects. These volunteers were also used as sources of polymorphonuclear leukocytes (PMNs).(1) Effect of early, fulminant ARDS and normal plasma on spontaneous Ao and GM-CSF receptor expression in PMNs in vitro. (2) Effect of ligation of either GM-CSF or its receptor with a neutralizing monoclonal antibody (mAb) on PMN Ao in ARDS and normal plasma. (3) Correlation of extracellular GM-CSF concentration with rate of PMN Ao. (4) Levels of GM-CSF in ARDS and normal plasma and in culture supernatant of normal PMNs incubated in early, fulminant ARDS and normal plasma.Plasma from patients with ARDS enhanced PMN viability at 24 hours (data are given as mean +/- SEM) 52% +/- 3% control vs 60% +/- 3% ARDS, P.05). Binding of the GM-CSF receptor with a neutralizing mAb significantly reduced PMN viability in ARDS plasma, but not in normal plasma (60% +/- 3% ARDS vs 53% +/- 3% ARDS + mAb, P.05). Ligation of GM-CSF with mAb had no significant effect on PMN viability in either plasma. Only 1% of PMNs expressed detectable levels of the GM-CSF receptor when incubated for 24 hours in either ARDS or normal plasma. The GM-CSF levels were undetectable (7 pg/mL) in both ARDS and normal plasma and in culture supernatants taken after 24 hours of incubation in both plasma types. Levels of GM-CSF ranging from 0 to 50000 pg/mL had no effect on PMN Ao in plasma-free medium.The antiapoptotic effect of ARDS plasma appears to be mediated by the GM-CSF receptor. This effect occurs at both low levels of plasma GM-CSF and surface expression of its PMN receptor. Ligation of GM-CSF had no effect of PMN Ao, suggesting that Ao is triggered by Fc portion-mediated receptor cross-linking. These results provide the theoretical basis for alphaGM-CSF receptor mAb therapy as a novel modality of treatment for ARDS.

Introduction: The preferred chest tube (CT) removal algorithm has not yet been established. The purpose of this study was to determine which technique, water seal or suction, allowed for shorter CT duration. In addition, the recurrent pneumothorax (PTX) rate, the need for CT reinsertion, and the total number of chest x-ray films (CXR) were determined. Methods: Prospective randomized trial of 205 trauma patients, older than 15 years of age, requiring tube thoracostomy for blunt and penetrating trauma. Patients requiring mechanical ventilation more than 24 hours were excluded from the study. Informed consent was obtained from all patients. Chest tubes were randomized for removal when output was less than 150 mL/24 hours, CXR revealed no significant PTX, and no air leak was present. Patients in the water seal group were disconnected from low wall suction and a CXR was obtained 6 to 8 hours later. Chest tubes in the no water seal group were disconnected from wall suction and pulled immediately. All tubes were removed by using standard protocol with patients at maximal inspiratory effort. A follow-up CXR was obtained after removal. Results: Of the 205 patients, 93 patients (45%) were randomized to the water seal group and 112 patients (54%) to the no water seal group. Four patients in the water seal group developed a PTX before CT removal and were considered treatment failures. After CT removal, repeat PTX was seen in 13 patients in the water seal group and in 9 patients in the no water seal group. However, seven patients in the no water seal group required CT reinsertion compared with one in the water seal group (p < 0.05). Average number of CXR in the water seal group was 6.5 compared with 5.5 radiographs in the no water seal group. There was no difference in chest tube duration or hospital length of stay between groups for either all patients or only those patients with isolated chest injuries. Patients who required another CT had a hospital length of stay twice that of patients who did not. Conclusions: It is possible that patients in the no water seal group did not have sufficient time for a possible PTX to evolve, which resulted in a larger and more significant PTX requiring another CT. Although there was no difference in chest tube duration between the no water seal and water seal groups, a short trial of water seal appears to allow occult air leaks to become clinically apparent and reduces the need for another CT.

Clinical neutrophil (PMN) priming is the net result of multiple stimuli, with intracellular calcium ([Ca 2+ ] i ) being a key second messenger for PMN agonists such as the chemokines. Thus, [Ca 2+ ] i measurement may be a robust tool for the assessment of global PMN activation. [Ca 2+ ] is difficult to measure in complex biologic environments, however, so data in this area are limited. We therefore developed an in vitro system to measure the effects of chemokines on PMN [Ca 2+ ] i , PMN were isolated from volunteer blood. PMN [Ca 2+ ] i responses to interleukin (IL)-8 and Growth-Related Oncogene (GRO)-α were studied by fura-2-acetoxymethyl ester fluorescence with or without reincubation in autologous plasma just prior to study. The effects of IL-8 and GRO-α on PMN [Ca 2+ ] i at ascending doses, with or without plasma reincubation, given sequentially and in the presence or absence of extracellular calcium, were studied. PMN basal [Ca 2+ ] i was increased by plasma, as were low-dose priming and higher-dose spike responses to IL-8. GRO-α caused a more pronounced priming of PMN [Ca 2+ ] i than IL-8 at low doses, although significantly lower peak responses were observed with GRO-α than IL-8 at higher doses. Plasma suppressed both priming and spike responses to GRO-α. When given serially at clinically relevant agonist doses, GRO-α was permissive of IL-8 signaling, whereas IL-8 blocked GRO-α signaling. IL-8 generates high [Ca 2+ ] i spikes using intracellular calcium stores only. GRO-α produces lower [Ca 2+ ] i spikes despite using both intra- and extracellular stores. Plasma preincubation has profound effects on PMN [Ca 2+ ] i responses to chemokines. These can be measured accurately, as described. In clinically relevant environments, IL-8 and GRO-α interact in a regulatory fashion. GRO-α may act as a priming agent, with IL-8 activating PMN functions requiring high [Ca 2+ ] i . This cross-cooperation is probably terminated by IL-8 regulation of GRO-α activity at the C-X-C chemokine receptor 2.

The immune environment of human soft-tissue injury is unstudied. We studied fracture soft-tissue hematomas (FxSTH) in 56 patients with high-energy bony fractures. FxSTH serum and mononuclear cells (MNC) as well as fracture patient plasma and blood MNC were studied. Twenty healthy controls donated plasma and MNC. Soluble tumor necrosis factor (TNF)-alpha, interleukin (IL-1 beta, IL-2, 6, 8, 10, 12, and interferon-gamma were studied by enzyme linked immunosorbent assay. Cells were studied by flow cytometry after cell-membrane stains for CD-14, TNF-alpha (mTNF), and human leukocyte antigen-DR, or intracellular stains for TNF (icTNF) and IL-10. Thirty-six patients with Injury Severity Score15 were analyzed further to evaluate the effects of isolated fracture on systemic immunity. Cytokines were rarely detectable in control plasma. TNF-alpha, IL-1 beta, IL-2, and interferon-gamma were rarely found in FxSTH serum or fracture patient plasma. All FxSTH sera were rich in IL-6, peaking before 48 hours (12,538 +/- 4,153 vs. 3,494 +/- 909 pg/mL, p = 0.02, U test). In Injury Severity Score15, IL-6 was not detectable in most early fracture patient plasma, but rose after 48 hours (p = 0.028). FxSTH serum IL-8 peaked after 48 hours (440 +/- 289 vs. 4,542 +/- 1,219 pg/mL, p = 0.006) and circulating IL-8 appeared after 72 hours. IL-6 and IL-8 showed gradients from FxSTH serum to paired PtS (p0.05, Wilcoxon). IL-10 was abundant (884 +/- 229 pg/mL) in FxSTH serum24 hours old. FxSTH serum IL-12 peaked late (3,323 +/- 799 pg/mL, day 4-7) then fell (p0.001, analysis of variance). Only IL-12 was higher in fracture patient plasma (1,279 +/- 602 pg/mL) than FxSTH serum (591 +/- 327 pg/mL) during the first 48 hours (p = 0.032, U test). On flow cytometry, control monocytes expressed 201 +/- 31 mTNF sites/cell, but icTNF was absent. mTNF was up-regulated after injury more in FxSTH monocytes (3,202 +/- 870 sites/cell) than peripheral blood monocytes (584 +/- 186 sites/cell) (p0.05 vs. peripheral blood monocytes by Wilcoxon, p0.001 vs. control monocytes by U test). Intracellular IL-10 was abundant in all MNC, but varied widely after injury. Fracture and peripheral blood monocytes expressed far less human leukocyte antigen-DR than control monocytes. Fractures create an inflammatory local environment. Proximal mediators are cell-associated and relatively confined to the wound, but soluble IL-6, IL-8, and IL-10 are abundant and probably exported. Systemic MNC have complex responses to local injuries. These may reflect the combined impact of multiple soluble cytokines initially generated within the wound. FxSTH appear to be a potentially important source of immunomodulatory cytokines in trauma.

Clinical trauma suppresses immunity and experimental wound fluids have been shown to be immunosuppressive. To ascertain whether human wounds contain immunosuppressive cytokines, we assayed serum from fracture/soft-tissue hematomas (FSTH) of 22 patients for interleukin (IL)-10, transforming growth factor (TGF)-beta 1, and IL-4. Results were correlated to concurrent plasma cytokine concentrations in the same patients and in volunteer plasma. IL-10 was present in high concentration (1376 +/- 539 pg/mL) in all (7/7) FSTH24 h old. In FSTH24 h old, IL-10 was found intermittently and at lower levels (239 +/- 106 pg/mL, p = .011 vs. FSTH24 h old). IL-10 was rarely detectable in fracture patient plasma and never detectable (20 pg/mL) in normal plasma. No significant variations of IL-4 or total TGF-beta 1 were found in FSTH or plasma. FSTH are significant potential sources of IL-10 activity in trauma patients, which may be overlooked when only plasma is assayed. The potential for a relationship between cytokines found locally at sites of injury and clinical immune modulation in trauma requires further study.

Objectives : To determine if patients with multiple lower extremity fractures have worse outcomes than do patients with isolated femur fractures, and to determine if the Abbreviated Injury Scale (AIS) should distinguish between single and multiple lower extremity fractures. Design : A retrospective study. Materials and Methods : All blunt trauma patients at least 15 years of age treated at a level 1 trauma center from January 1990 through December 1993. Three groups of patients were selected. Group I included 50 patients whose only significant injury was a diaphyseal femur fracture. They had no other long bone fractures, minimal injuries to other body areas, and an Injury Severity Score (ISS) ≤ 14. Group 2 was consisted of 29 patients with a femur fracture, at least one other diaphyseal lower extremity fracture, and also an ISS ≤ 14. Group 3 consisted of 23 patients who had fracture patterns similar to those of group 2, but also had more severe nonextremity injuries (ISS ≥ 15). Hospital morbidity and mortality rates were compared with t tests or chi-square analysis. Type 1 error probability was established at p < 0.05. Measurements and Main Results : Compared with patients in group 1, patients in group 2 had an identical ISS (10.1 vs. 10.6, respectively), but had higher transfusion requirements (0.3 vs. 3.9 units), more days in the intensive care unit (ICU) (0.02 vs. 1.4), a higher incidence of adult respiratory distress syndrome (ARDS) (0 vs. 14%), longer hospital stays (6.0 vs. 14.8 days), greater disability at discharge (disability score 2.2 vs. 3.2), and a higher mortality rate (0 vs. 3.4% ; p < 0.05 all variables). Patients in group 3 had worse outcomes than the other two groups : ISS = 30.1 ; transfusions = 11.9 units ; ICU days = 9.1 ; ARDS incidence = 26% ; hospital days = 29.9 ; disability score = 3.9 ; mortality = 26% (p < 0.05). Conclusions : Although AIS and ISS appropriately reflect the impact of extraskeletal injuries in patients with femur fractures, they do not adequately reflect the increased morbidity associated with multiple lower extremity fractures. The AIS-Extremity Score may need to be upgraded for multiple long bone fractures of the lower extremities.

Background: Trauma is believed to activate immunocytes but paradoxically also increases the risk of intraperitoneal infection. Objective: To investigate these events by evaluating changes in the cytokine control networks of human peritoneal macrophages (PMo) early after trauma. Design: Case-control study comparing cytokine messenger RNA (mRNA) expression by PMo from patients with extra-abdominal trauma with that of both peripheral blood mononuclear cells (PBM) and PMo obtained from healthy individuals. Setting: Level I trauma center and basic science laboratory in a university hospital center. Patients: Six patients with polytrauma (Injury Severity Score, ≥15) with clinically negative diagnostic peritoneal lavages performed on routine indications at admission to the emergency department and six healthy age- and sex-matched individuals undergoing inguinal herniorrhaphy under local anesthesia. Interventions: Peritoneal macrophages were isolated from diagnostic peritoneal lavages in trauma patients. Identical lavages were performed through the hernia sac in the control group. Measurements: Cellular RNA was assayed for tumor necrosis factor α (TNF-α), interleukin-1β, IL-6, and IL-10 message by semiquantitative reverse-transcription polymerase chain reaction. Results: Normal PMo expressed high levels of TNF-α mRNA relative to PBM, but expression of the other proinflammatory cytokines was equivalent to that of PBM. Peritoneal macrophage expression of TNF-α mRNA was markedly (64-fold) decreased after trauma ( P P =.03). Conclusions: Human PMo constitutively show high levels of TNF-α message expression, and this is down-regulated by polytrauma. This might constitute a functionally "primed" state. If so, TNF-α down-regulation might contribute to functional PMo suppression after systemic injury. (Arch Surg. 1995;130:1186-1192)

Trauma is a major cause of death worldwide, with some 30% of deaths associated with hemorrhage. Rapid control of bleeding in such patients is thus an essential aspect of trauma care. Recombinant human factor VIIa is sometimes used off-label in massively bleeding patients and has been demonstrated in two randomized trials to significantly reduce the need for blood transfusions. Whether this translates into improved outcomes has not been determined, most notably because mortality appears to be much lower than in the past as a result of improved general care of trauma patients. In this setting it may be increasingly difficult to demonstrate that any intervention can influence survival since the number of patients needed for sufficient power is so high and the duration needed for recruitment of the patients too long. In the present commentary, we reflect on how we can move forward in the management of severely bleeding trauma patients in the current environment. © 2011 BioMed Central Ltd., Editorial, SCOPUS: no.j, info:eu-repo/semantics/published

Introduction: Neutrophil (PMN) functions are regulated by cytosolic calcium ([Ca2+]i). Calcium channel blockade could therefore limit the inflammatory response to shock, but current calcium channel blockers target L-type channels and thus can exacerbate shock. PMN Ca2+ mobilization however, occurs via store-operated calcium channels (SOCC) that can be targeted selectively. We hypothesized that SOCC blockade might suppress PMN function, lessening lung injury in shock while avoiding compromise of cardiovascular compensations. Methods: Human PMN chemotaxis (CTX) was studied in a modified Boyden chamber in the presence of N-propargyl-nitrendipine (MRS1845), an inhibitor of SOCC. Rats then underwent trauma and hemorrhagic shock (laparotomy plus hemorrhage to MAP 30–40mmHg × 90min [T/HS]) with 30 microM MRS or vehicle (DMSO) given IP at laparotomy. PMN CD11b expression (flow cytometry) and lung injury (% Evans Blue dye [EBD] leak) were studied 3h-post resuscitation. The volume of shed blood needed to achieve shock was measured. Results: In vitro, MRS1845 caused dose-dependent suppression of CTX (IC50 = 30 microM, P

Methods: Sprague-Dawley rats were divided into 3 groups: unmanipulated controls (C), shock (SH), or shock with lymph ligation (SLL). Shocked animals (MAP 5 30mmHg for 90 min) underwent laparotomy 6 mesenteric lymph ligation. Rats were resuscitated with shed blood and fluid. Groups were sacrificed at 3 hours and BM mononuclear cells were cultured for myeloid (CFU-GM) and erythroid (CFU-E) progenitors, and immature progenitors (cobblestone area forming cells, CAFC). We also determined the effects of plasma from C, SH or SLL rats on CFU-GM and CFU-E by culturing BM cells from normal rats with plasma (2% v/v).

Background: Patients with major fracture/soft-tissue injuries are at risk for adult respiratory distress syndrome after secondary infection. Fracture fluids (FF) are rich in neutrophil (PMN) -specific chemokines such as interleukin-8. PMN respond to both interleukin-8 and bacterial stimuli with calcium ([Ca 2+ ] i ) fluxes, which can initiate respiratory burst (RB). We hypothesize that small amounts of FF entering the circulation could exaggerate PMN [Ca 2+ ] i and RB responses, potentially increasing the risk of adult respiratory distress syndrome. Methods: FF were obtained from 10 patients at open fixation of the femur 2 to 5 days postinjury. Volunteer PMN were isolated and loaded with fura dye. PMN were preincubated either in 30% autologous plasma (AP)/70% buffer, or in 5% FF/25% AP/70% buffer. Cells were resuspended in buffer with 1,2,3-dihydrorhodamine and stimulated with low-dose n-formylmethionyl-leucyl-phenylalanine (fMLP). [Ca 2+ ] i was assayed by fura fluorescence at 505 nm after excitation at 340/380 nm. RB was assessed by 1,2,3-dihydrorhodamine fluorescence at 530 nm after 488 nm excitation. Results: PMN basal [Ca 2+ ] i was higher after FF incubation than AP incubation (94 ± 12 vs. 61 ± 9 nmol/L, p = 0.0002). Peak [Ca 2+ ] i response to fMLP was 475 ± 47 nmol/L after FF but only 356 ± 22 nmol/L after AP (p = 0.01). Two hundred seconds after fMLP, [Ca 2+ ] i remained higher after FF (172 ± 17 vs. 145 ± 9 nmol/L, p = 0.04). Basal RB was slightly higher after FF than AP (13.4 ± 0.3 vs. 11.3 ± 0.3 units, p = 0.051) as was the maximal rate of extracellular oxidant release (1.10 ± 0.17 vs. 0.76 ± 0.16 units/s, p = 0.004) and total oxidant production (42.5 ± 0.8 vs. 31.7 ± 0.8 units, p = 0.006). Conclusion: Small amounts of FF in plasma can exaggerate PMN [Ca 2+ ] i flux and RB responses to subsequent bacterial stimuli. These findings are consistent with the hypothesis that release of FF into the circulation primes PMN and, thus, may predispose to adult respiratory distress syndrome. Such PMN priming events might have important implications for both the operative and medical management of patients with major fractures.

Objectives: To determine the effect of hypoxia on bone marrow mononuclear cells (BMMCs) and their ability to proliferate into granulocyte-macrophage colony-forming units (CFU-GMs) and erythroid burst-forming units (BFU-Es) and to determine the role of the neuroimmune and hematopoietic mediator, substance P. Design: Controlled in vitro study. Setting: University research laboratory. Materials: Bone marrow aspirates were obtained from the posterior iliac crests of healthy volunteers after obtaining informed consent. Interventions: The BMMCs were divided into the following groups: (1) normoxia, (2) two hours of hypoxia, and (3) six hours of hypoxia. Additional BMMCs were purified before the period of hypoxia, while others were incubated with neurokinin (NK) receptor antagonists. In other experiments, bone marrow stroma was grown to confluence and randomized to the following groups: (1) normoxia, (2) hypoxia, (3) normoxia and interleukin (IL) 1, and (4) hypoxia and IL-1. All groups were cultured for 2, 6, 12, or 24 hours. Main Outcome Measures: The formation of CFU-GMs and BFU-Es was measured after 10 to 14 days of incubation of the BMMCs. The messenger RNA of the preprotachykinin-l (PPT-I) gene and the NK-1 and NK-2 receptors was detected by using semiquantitative reverse transcriptase-polymerase chain reaction or Northern blot analysis on bone marrow stroma. The immunoreactivity of substance P in bone marrow stroma was measured by competitive enzyme-linked immunosorbent assay. Results: Hypoxia resulted in a 110% increase in the number of CFU-GMs and a 78% increase in the number of BFU-E colonies at 6 hours (both P

To evaluate the role of interleukin 8 (IL-8) in the regulation of neutrophil (PMN) apoptosis in normal plasma and plasma from patients with early, fulminant acute respiratory distress syndrome (ARDS).Experimental study using cultured human PMNs.University hospital, level I trauma center.Plasma was obtained from 6 patients with early, fulminant posttraumatic ARDS (mean Injury Severity Score, 26). All samples were drawn within 24 hours after injury. Plasma was also taken from 13 healthy control subjects. These controls were also used as sources of PMNs.Effect of early, fulminant ARDS and normal plasma on spontaneous apoptosis, CD16, and CD11-b expression in PMNs in vitro; levels of IL-8 in plasma; correlation of extracellular IL-8 concentration with rate of PMN apoptosis; and effect of IL-8 blockade on PMN apoptosis, CD16, and CD11-b expression in ARDS and normal plasma.Plasma from patients with early, fulminant ARDS inhibited spontaneous PMN apoptosis at 24 hours (35%+/-5% vs 54%+/-5%; P=.01). Neither CD16 nor CD1l-b differed significantly between the 2 groups. The mean plasma level of IL-8 in patients with early, fulminant ARDS was 359+/-161 pg/mL vs 3.0+/-0.4 pg/mL in healthy controls (P.05). Interleukin 8 inhibited apoptosis in plasma-free medium at low doses (1-50 pg/mL) but had no significant effect at higher doses (100-5000 pg/mL) (P.05). Interleukin 8 blockade with monoclonal antibody suppressed apoptosis in normal plasma (28%+/-5% with monoclonal antibody vs 51%+/-5% without monoclonal antibody; P=.008) but not in plasma from patients with early, fulminant ARDS (29%+/-5% with monoclonal antibody vs 34%+/-6% without monoclonal antibody; P=.67). It had no effect on CD16 or CD11-b expression in either plasma.Plasma from patients with early, fulminant ARDS contains soluble factors that inhibit PMN apoptosis in vitro. Low levels of IL-8 inhibit PMN apoptosis in normal plasma. Although plasma levels of IL-8 are markedly elevated in early, fulminant ARDS, IL-8 is not directly responsible for the antiapoptotic effect of plasma from patients with early, fulminant ARDS.

Background: Natural killer cells (NKCs) participate in "innate" cell-mediated immunity. Fracture/soft tissue injuries are cytokine rich and may influence cell-mediated immunity. Objective: To study the effects of fracture cytokines on NKC function. Design: A case-control study. Setting: A level I trauma center and laboratory in a university medical center. Participants: Patients requiring open fracture fixation and healthy volunteers. Interventions: Fracture supernatants and peripheral plasma were collected during open fracture fixation. Volunteer mononuclear cells were used as effector (NKC) sources. Mononuclear cells were preincubated with fracture supernatants, paired peripheral plasma, or normal plasma under various conditions. Main Outcome Measures: Natural killer cell lysis of K562 target cells was assessed by chromium 51 release. Results: Fracture supernatants suppressed NKC function more rapidly than peripheral plasma. Fracture supernatants from 1 to 4 days after injury were most suppressive. Inactivation of complement and reactive oxygen species failed to restore lysis. Neutralizing antibodies to interleukin 4 and interleukin 10 further suppressed lysis. Antibodies to transforming growth factor β1 failed to restore lysis. The addition of interferon γ did not restore lysis but the addition of interleukin 12 did. Conclusions: Fracture supernatants and peripheral plasma from patients with fractures suppress NKCs. The responsible mediators may be concentrated in fracture/ soft tissue injuries. Responses to manipulation of the cytokine environment suggest that fracture cytokines may impair cooperation between NKCs and accessory cells. Arch Surg. 1997;132:1326-1330