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:

PurposeThe purpose of this study was to determine the effect of endotoxin on vasorelaxation in the pulmonary and systemic circulations in response to the following agonists that require generation of cyclic adenosine monophosphate: (1) beta-adrenergic receptor stimulation with isoproterenol; (2) H2receptor stimulation with dimaprit; and (3) adenylate cyclase stimulation with forskolin.MethodsMale Sprague-Dawley rats weighing 250 to 350 g were injected with endotoxin (20 mg/kg intraperitoneal) or saline. Six hours later, the cumulative dose response to beta-adrenergic receptor stimulation (isoproterenol), H2receptor stimulation (dimaprit), and adenylate cyclase stimulation (forskolin) was determined in isolated rat pulmonary artery and thoracic aortic rings preconstricted with phenylephrine.ResultsEndotoxin caused significant impairment of relaxation to isoproterenol in the pulmonary artery, but the response in the aorta was not different from the control response. In the pulmonary circulation, endotoxin converted the response to dimaprit from vasorelaxation to vasoconstriction. On the other hand, dimaprit resulted in vasorelaxation in the thoracic aorta after endotoxin; however, the response was impaired compared with the control response. Endotoxin did not affect the dose response to forskolin in either the pulmonary artery or the thoracic aorta.ConclusionFrom these data, we conclude that endotoxin causes regional specific changes in vascular reactivity. These changes in vascular reactivity result in preserved vasorelaxation in the systemic circulation and impairment of vasorelaxation in the pulmonary circulation in response to endotoxin.

ISSN:0022-5282    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

BackgroundThe gastric intramucosal pH (pHi) and gastric mucosal-arterial CO2gap (GAP) estimate visceral perfusion and predict outcome. Threshold values of these variables for use during resuscitation, however, remain poorly defined. The purpose of this study was to develop clinically derived cutoffs for both pHi and GAP for predicting death and multiple organ failure (MOF) in trauma patients.MethodsThis was a cohort study of 114 consecutive trauma patients who had pHi determined at 24 hours after intensive care unit admission. The corresponding GAP for each of these values of pHi was obtained through chart review. Receiver operating characteristic curves were constructed for both pHi and GAP with respect to death and MOF. These curves were used to determine the value of each variable that maximized the sum of sensitivity and specificity in predicting outcome. chi squared tests and odds ratios were used to determine if significant differences in outcome occurred above and below these cutoff values.ResultsOf 114 patients who had pHi determined at 24 hours after admission, 108 had corresponding GAP values available. The values of pHi and GAP that maximized sensitivity and specificity were 7.25 and 18 mm Hg, respectively. The odds ratio for pHi versus death was 4.6 and for pHi versus MOF was 4.3. The odds ratios for GAP versus death and MOF were 2.9 and 3.3, respectively.ConclusionIn trauma patients, the ability to predict death and MOF is maximized at values of pHi less than 7.25 and GAP greater than 18 mm Hg. These values represent clinically derived cutoffs that should be useful for evaluating the adequacy of intestinal perfusion during resuscitation.

ISSN:0022-5282    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

BackgroundBase deficit has been used as a marker of significant injury and to predict resource utilization and mortality. The significance of base deficit in trauma patients 55 years and older has not been specifically evaluated. The purpose of this study was to determine the utility of base deficit in assessing older trauma patients versus a younger cohort.MethodsData were obtained from the trauma registry on trauma patients admitted to a Level I trauma center. Arterial blood gases were obtained within 1 hour of arrival, by protocol, in 2,631 patients, and of these, 274 patients were 55 years or older. Data are presented as means +/- SEM. Statistical analysis was done by paired t test, analysis of variance, and chi squared analysis. Significance was attributed to a p value < 0.05.Resultsor=to 16 for 76% of patients younger than 55 years and 78% of patients 55 years and older. The negative predictive value of a normal base deficit for Injury Severity Scores <or=to 16 was 60% for the younger cohort and only 40% for patients 55 years and older (p < 0.001; chi squared).ConclusionsA base deficit of <or=to -6 is a marker of severe injury and significant mortality in all trauma patients, but it is particularly ominous in patients 55 years and older. Patients older than 55 years may have significant injuries and mortality risk without manifesting a base deficit out of the normal range.

ISSN:0022-5282    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

BackgroundThe focused assessment for the sonographic examination of the trauma patient (FAST) is a rapid diagnostic test that sequentially surveys for hemopericardium and then the right upper quadrant (RUQ), left upper quadrant (LUQ), and pelvis for hemoperitoneum in patients with potential truncal injuries. The sequence of the abdominal part of the examination, however, has yet to be validated. The objectives of this multicenter study were as follows: (1) to determine where hemoperitoneum is most frequently identified on positive FAST examinations; and (2) to determine if a relationship exists between that areas and the organs injured.MethodsUltrasound registries from four Level I trauma centers identified patients who had true-positive FAST examinations. Demographic data, areas positive on the FAST, and organs injured were recorded; injuries were classified as multiple, single solid organ (liver or spleen), isolated hollow viscus, or retroperitoneal. Relationships between positive locations on the FAST examinations and the associations of organs injured to areas positive were assessed using McNamara's chi squared test; a p value < 0.05 was considered statistically significant.ResultsThe RUQ was the most common site where hemoperitoneum was detected, and this was statistically significant compared with either the LUQ or the pelvis. Also, statistically significant correlations (p < 0.001) were observed between positive RUQ areas on the FAST and multiple injuries, single solid organ (liver or spleen) injury, and retroperitoneal injuries.ConclusionBlood is most often found on the FAST in the RUQ area in patients with multiple intraperitoneal injuries or isolated injury to the liver, spleen, or retroperitoneum, but not when there is injury to a hollow viscus.

ISSN:0022-5282    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

BackgroundThe timely treatment of patients with head injuries is affected by the availability and commitment of neurosurgeons. Use of midlevel practitioners (MLPs) may permit more efficient neurosurgical coverage. Intracranial pressure monitoring is among the most frequently used neurosurgical procedures. The purpose of this study was to examine the placement of intracranial pressure (ICP) monitors by MLPs.MethodsMedical records and trauma registry data for a Level I trauma center were reviewed from December 1993 to June 1997. Patients who had ICP monitors placed were included. Patient data recorded were age, mechanism of injury, injury type, ICP monitor placement and length of placement, complications related to the ICP monitor, and outcomes.ResultsTwo hundred ten patients had 215 monitors placed. ICP monitors were placed by neurosurgeons (105), MLPs (97), and general surgery residents (13), and remained in place a mean of 4 days. No major complications attributable to ICP monitor placement occurred; 19 minor complications (malfunction, dislodgment) were noted. Eleven monitors placed by neurosurgeons (10%), seven placed by MLPs (7%), and one placed by a resident (8%) had complications.ConclusionICP monitor placement by MLPs is safe. Use of MLPs may aid neurosurgeons in providing prompt monitoring of patients with head injuries.

ISSN:0022-5282    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

BackgroundIt is our practice to treat suspected sepsis with imipenem/cilastatin and gentamicin (IMP/GENT) for 72 hours while awaiting culture results. We wanted to determine if this practice engenders antimicrobial resistance.MethodsReview of prospectively collected data regarding use of IMP/GENT and microbial sensitivity to imipenem/cilastatin during the first and last 7 months of a 19-month study period (October 1, 1995, to April 30, 1997).ResultsThe susceptibility of appropriate organisms to imipenem/cilastatin was 76% in the early period and 80% in the late period (p = 0.42). Pseudomonas aeruginosa was more susceptible in the late period (88 vs. 62%; p = 0.007). Resistance to gentamicin (30% early vs. 21% late; p = 0.02) and representative cephalosporins (cefoxitin, 52% early vs. 61% late; p = 0.35; ceftazidime, 26% early vs. 23% late; p = 0.76) did not develop during the study period. The incidence of fungemia was the same in both periods (4 of 467 admissions vs. 3 of 599 admissions; p = 0.48).ConclusionThis protocol did not lead to the emergence of resistant bacteria.

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:

BackgroundPrevious models comparing normal saline (NS) with lactated Ringer's solution (LR) for resuscitation use only mild or moderate hemorrhage and do not address the clinical situation of massive hemorrhage and resuscitation (MHR). This work compares NS and LR by using a new rat model of MHR.MethodsNS and LR were compared by using both a traditional model of moderate pressure-controlled hemorrhage and a model of MHR. Moderate hemorrhage animals were bled to mean arterial pressure (MAP) = 60 mm Hg x 2 hour then resuscitated with crystalloid (NS or LR) for 1 hour. MHR animals were bled at a rate of 1 estimated blood volume (EBV) per hour for 2 hours with simultaneous resuscitation by using washed red blood cells (B) and crystalloid (LR+B or NS+B). MAP was kept at 60 mm Hg during the 2 hours of hemorrhage. Bleeding was then stopped, and animals were resuscitated for 1 additional hour with blood and crystalloid to MAP more than 90 mm Hg or until 10x EBV was given. Group means were compared with Student's t test (p < 0.01 significant) and 2-week survival rates were compared by using Fisher's exact test (p < 0.05 significant).ResultsThe moderate hemorrhage group was bled 36% of EBV. In this setting, resuscitation with NS and LR was equivalent. The final hematocrit, pH, and base excess were not different, and all animals survived in both groups. MHR animals were bled 218% of EBV. Animals resuscitated with NS+B were significantly more acidotic than animals resuscitated with equal volumes of LR+B (pH 7.14 +/- .06 vs. 7.39 +/- .04, respectively) and had significantly worse survival (50% vs. 100%, respectively).ConclusionWith moderate hemorrhage, NS and LR are equivalent, but in the setting of massive hemorrhage and resuscitation, significantly more physiologic derangement and mortality occurs with NS than LR. LR is superior to NS for use in massive resuscitation.

ISSN:0022-5282    

出版商:OVID    

年代:1998

数据来源: OVID