ISSN:0022-5282    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

BackgroundBiochemical serum markers commonly used to assess human cardiac injury (creatinine phosphokinase, creatine phosphokinase-MB) have been shown to have diminished specificity for detection of cardiac injury in the setting of burn-related soft-tissue and skeletal muscle injury. Laboratory studies have demonstrated that severe cutaneous thermal injury is associated with cardiac contractile dysfunction and a corresponding elevation in serum cardiac troponin-I (cTn-I) in several species.MethodsTwenty-three patients admitted to a tertiary care burn referral center were evaluated. Patients were monitored with pulmonary artery catheters, and creatinine phosphokinase, creatine phosphokinase-MB, and cTn-I levels were determined for 24 hours. Using a database, 6,722 burn patients were reviewed to determine the incidence of preexisting cardiac disease and postburn cardiac complications.Results115 beats per minute) without obvious electrical anomalies. All patients centrally monitored with a pulmonary artery catheter (n = 20) maintained a cardiac index of greater than 3.0 L[center dot]min-1[center dot]m-20.55 ng/mL) at 24 hours for all burns of more than 18% total body surface area. Historically, although only 5% of all admissions manifest acute postburn cardiac complications, 94% of these patients presented with preexisting heart disease.ConclusionSevere thermal injury was associated with a mild elevation in serum troponin-I; however, this did not correlate with overt cardiac morbidity or mortality. Postburn elevation of cTn-I suggested that a subtle degree of cardiac injury was present after a severe thermal injury despite hyperdynamic cardiac function during resuscitation.

ISSN:0022-5282    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

BackgroundBinding of the leukocyte glycoprotein L-selectin to ligands expressed by activated endothelium directs leukocyte recruitment to areas of acute inflammation. Sequestration by activated microvascular endothelium has been proposed to explain the low plasma concentrations of soluble L-selectin (sCD62L) observed early in patients with acute respiratory distress syndrome. We hypothesized that inflammatory endothelial activation may occur in trauma patients, leading to decreased sCD62L plasma concentrations.MethodsThis study was a prospective analysis of sCD62L plasma concentrations in patients with isolated head injuries and multiple trauma patients without head injuries admitted to two tertiary-level intensive care units. sCD62L plasma concentrations were determined in 18 consecutive adult patients with isolated moderate and severe head injuries and in 13 multiple trauma patients without head injuries immediately upon admission to the intensive care unit and then daily for up to 10 days after trauma.ResultsCompared with healthy adult controls (n = 22), patient sCD62L plasma concentrations were significantly decreased upon admission (5.7 +/- 1.6 vs. 11.0 +/- 1.7 pmol/mL; p < 0.001). In all patients, sCD62L concentrations remained depressed throughout the study period. sCD62L concentrations did not differ significantly between patients with isolated head injuries and multiple trauma patients without head injuries, although repeated-measures analysis of variance showed significantly more depressed sCD62L concentrations associated with severe (n = 14) compared with moderate head injuries (n = 4) during the study period (p < 0.05).ConclusionPatients with major trauma present with a significant reduction of sCD62L plasma concentrations within the first 12 hours after trauma and during subsequent intensive care. This finding suggests widespread microvascular endothelial activation after trauma, which may be associated with increased neutrophil extravasation.

ISSN:0022-5282    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

ObjectiveTo investigate the relationship between secondary muscle damage after contusion and the interactions between leukocytes and endothelial cells, which are essential steps in secondary inflammatory response.MethodsIn a randomized animal study, rats were chronically instrumented with dorsal skinfold microvascular chambers and exposed to standardized contusion or sham contusion. Leukocyte rolling and adherence in postcapillary venules before and after muscle contusion or sham contusion were quantitated using in vivo microscopy.ResultsThe number of rolling leukocytes in the postcapillary venules before contusion was low. At 300 minutes after contusion, the number of rolling and adherent leukocytes in the striated muscle microvasculature was increased significantly (p <or=to 0.05) compared with either the baseline precontusion condition or the control group at the same time.ConclusionIn the mid-term to long-term stages of skeletal muscle injury associated with contusion, a significant portion of tissue damage is secondary to leukocyte-endothelial cell interactions.

ISSN:0022-5282    

出版商:OVID    

年代:1998

数据来源: OVID

ISSN:0022-5282    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

ObjectivesCellular metabolism is dependent on the local temperature in tissues. Induced hypothermia has been shown to be protective in a number of conditions, especially traumatic, ischemic, burn, and neurological injury. However, the protective mechanisms of cold therapy remain controversial and the hemodynamic changes in the microcirculation of striated muscles in response to hypothermia have not been studied in detail previously.MethodsIn this study, we investigated the microvascular response of local cooling and rewarming in the striated muscle of hamsters by use of the dorsal skinfold preparation and in vivo fluorescence microscopy.ResultsWe found that reduction of the surface temperature to 8[degree sign]C for 30 minutes caused arteriolar vasoconstriction with a decrease in diameters by 43 +/- 7% while the venular and capillary diameters remained unchanged. The cooling procedure also markedly reduced the functional capillary density and the blood flow velocity and diameters in all vessel types, i.e., arterioles, venules, and capillaries. Moreover, the percentage of capillaries with no flow increased from 0.4 +/- 0.5% to 44 +/- 14% after 10 minutes of cold therapy. However, these hemodynamic changes induced by local hypothermia were completely reversed to the precooling values after termination of cooling and 30 min of rewarming. Strikingly, we found no increase in the number of adherent leukocytes and vascular permeability after the cooling and rewarming period, while, in contrast, additional experiments with warm ischemia (30 minutes) and reperfusion (30 minutes), i.e., reduced microvascular perfusion and reperfusion at normothermia, caused a sustained decrease in local perfusion and a nine-fold increase in venular leukocyte adhesion.ConclusionsTaken together, our functional data demonstrate that hypothermia markedly reduces microvascular perfusion, which is completely restored upon rewarming. The reduced microvascular perfusion during hypothermia did not provoke an inflammatory response, whereas leukocyte recruitment was prominent after reduced perfusion at normothermia, indicating that transient hypothermia has no adverse effects on microvascular parameters in the striated muscle in vivo.

ISSN:0022-5282    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

ObjectivePulmonary complications after intramedullary femoral nailing have been attributed to bone marrow fat embolization and a variety of cascade effects. We investigated whether the coagulatory response after intramedullary femoral nailing in merino sheep is altered after severe trauma.MethodsAdult merino sheep were submitted to hemorrhagic shock (2 hours, 50 mm Hg) and unilateral lung contusion. After recovery (day 3 of the study), reamed femoral intramedullary nailing (RFN), unreamed femoral intramedullary nailing (UFN), or plate osteosynthesis of the femur (P) was performed. Pulmonary artery pressure, central venous levels of factor V, protein C, antithrombin III, and fibrinogen, were determined. At 1 and 3 days before and after femur instrumentation, pulmonary capillary permeability was assessed on the basis of the comparative albumin content in bronchoalveolar lavage fluid.ResultsGroup RFN, n = 8; group UFN, n = 7; group P, n = 6. A significant (p < 0.05) postoperative increase in the relative albumin content in terms of the BAL/plasma albumin ratio was measured in group RFN (day 3 preoperatively: 0.38 +/- 0.05 day 3 postoperatively: 0.53 +/- 0.06, p < 0.05 (RFN vs. P), which contrasted with group UFN (day 3 preoperatively: 0.44 +/- 0.09, day 3 postoperatively: 0.46 +/- 0.09, no significant difference). This evidence of increased pulmonary permeability occurred in association with evidence of increased activation of coagulation factors (data presented as percentage of day 3 preoperative baseline values). The data for fibrinogen (15 min postoperatively) is as follows: group RFN, 74 +/- 9% (p < 0.05 vs. P); group UFN, 83 +/- 8% (not significant); group P, 98 +/- 6%. The data for antithrombin III (15 min. postoperatively) is as follows: group RFN, 72 +/- 6% (p < 0.05 vs. P); group UFN, 79 +/- 8% (not significant); group P, 92 +/- 8% (not significant).ConclusionAfter severe trauma, an increase of pulmonary permeability after reamed femoral nailing was associated with increased consumption of coagulation factors. After unreamed nailing, a similar trend was apparent, but this was not found to be statistically significant. These data provide support for the theory that after severe trauma, unreamed femoral nailing reduces but does not abolish pulmonary sequelae when compared with reamed femoral nailing.

ISSN:0022-5282    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

BackgroundThe purpose of this study was to evaluate prospectively the efficacy of subtalar distractional realignment arthrodesis in the treatment of calcaneal malunion associated with subtalar arthritis, collapse of height, talonavicular subluxation, malalignment of the heel axis, and widening heel with calcaneofibular abutment.MethodsThirty-four patients with severe calcaneal malunion were treated with a lateral approach, lateral decompression, medial subtalar capsulotomy, and distraction and realignment of the subtalar joint with an anteriorly and laterally tapered wedge bone graft. The patients were evaluated with a functional rating scale and radiographs, both before and after surgery.ResultsThirty-two of the 34 patients were evaluated at a mean of 71 months (range, 60-92 months) after the arthrodesis. Solid subtalar fusion was achieved in 31 of the 32 patients. The average gain of subtalar distraction was 12 mm. Neutral or mild valgus alignment was achieved in 26 of the 32 patients. The mean postoperative score (83) showed significant improvement over the mean preoperative score (47). Overall, the functional rating scale revealed excellent or good results in 26 patients and fair results in 6 patients.ConclusionCoupled with wedge bone grafting, the subtalar distractional realignment arthrodesis achieved restoration of hindfoot height and axial alignment with a good union rate and significant improvement in the majority of patients with calcaneal malunion.

ISSN:0022-5282    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

BackgroundThe potential to produce fat embolism may be important in determining the ideal method and timing of fracture treatment in patients with preexisting lung injury.MethodsFour dogs underwent femoral and tibial canal reaming and pressurization. Blood gas samples were analyzed, and pulmonary arterial pressure was monitored at 1 and 72 hours. Animals were killed 72 hours postoperatively, and the lungs, kidneys, and brain were examined histologically and compared with equivalent specimens from four control dogs that had not undergone femoral and tibial canal reaming and pressurization.ResultsPostmortem, intravascular fat persisted for 72 hours after induction of pulmonary fat embolism. Mean PaO2was unchanged from baseline at 72 hours after canal pressurization. Canal pressurization caused a sustained increase in pulmonary arterial pressure (p = 0.02) for 1 hour after canal pressurization. The mean pulmonary edema score at 72 hours was 29 +/- 3. Only a scant polymorph infiltrate (zero to two polymorphs per high-power field) was present at any time. No hyaline membranes were seen at any time. The percentage area occupied by intravascular fat in the lungs was 0.0214 +/- 0.0058 at 72 hours. No signs of ischemia or inflammation were seen in either the cerebral or the renal specimens.ConclusionThis study is the first to show that intravascular fat persists in the lungs, kidneys, and brain for 72 hours after canal pressurization and, by itself, does not cause pathologic evidence of acute inflammation.

ISSN:0022-5282    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

ObjectiveTo compare the effects of unreamed and reamed intramedullary nailing on the systemic production of prostacyclin and thromboxane A2as assessed, respectively, by determinations of urinary 2,3-dinor-6-ketoprostaglandin F1alpha and 11-dehydrothromboxane B2excretion.MethodsTen otherwise healthy patients with closed and simple tibial shaft fractures were treated with unreamed intramedullary nailing, and 10 otherwise healthy patients with closed and simple tibial shaft fractures were treated with reamed intramedullary nailing. Urine was collected preoperatively and during the next 5 postoperative days. The samples were stored at -70[degree sign]C until assayed at the end of the study.ResultsIn the unreamed group, urinary 2,3-dinor-6-ketoprostaglandin F1alpha and 11-dehydrothromboxane B2excretion remained stable and at a significantly lower levels compared with the reamed group during the entire study period (p < 0.021). In the reamed group, the alteration in urinary 2,3-dinor-6-ketoprostaglandin F1alpha excretion preoperatively and on the first postoperative day was nearly significant (p = 0.075), and the increase in urinary 11-dehydrothromboxane B2excretion was significant (p = 0.020). The proportional increase compared with baseline, however, was 1.6 times greater for 11-dehydrothromboxane B2than for 2,3-dinor-6-ketoprostaglandin F1alpha.ConclusionOnly reamed intramedullary nailing elevates urinary 2,3-dinor-6-ketoprostaglandin F1alpha and 11-dehydrothromboxane B2concentrations and their ratio (thromboxane A2/prostacyclinproduction) in patients with simple tibial shaft fractures.

ISSN:0022-5282    

出版商:OVID    

年代:1998

数据来源: OVID