ISSN:0090-3493    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

ObjectiveTo determine the in vivo neutralizing activities of anti-interleukin-6 (IL-6) antibody on survival rate and host defense in a clinically relevant model of infection.DesignProspective, randomized, experimental animal study.SettingUniversity and Shriners Burns Institute research laboratories.SubjectsTwo hundred seventy-six adult, female Balb/c mice.InterventionsBalb/c mice were treated with 10 micro gram of antimurine IL-6 antibody, nonspecific murine immunoglobulin G (IgG), or placebo at 2, 4, or 8 hrs after they underwent bacterial challenge by gavage of 1010Escherichia coli and thermal injury. The survival rate was determined. The number of viable translocated bacteria, the total amount of translocation, and the percentage of bacteria that survived were also studied in different tissues.Measurements and Main ResultsSurvival rate after burn and gavage was significantly improved in animals treated with antimurine IL-6 antibody at 2 and 4 hrs but not at 8 hrs after injury compared with control animals treated with nonspecific IgG or saline. The IL-6 serum concentration was significantly lower after burn and gavage in the animals treated 2 and 4 hrs after injury compared with nontreated animals. Better killing of translocated bacteria was observed in the tissues of animals treated with antimurine IL-6 antibody 2 hrs after injury.ConclusionsTreatment with antimurine IL-6 antibody at 2 and 4 hrs after injury, but not at 8 hrs after injury, positively affects outcome during gut-derived sepsis. Moreover, the beneficial effect of treatment after 2 hrs was related to an enhanced clearance of translocated bacteria.(Crit Care Med 1995; 23:1945-1953)

ISSN:0090-3493    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

ObjectiveTo determine whether cate-cholamine and cortisol secretory responses to surgery contribute to postoperative complications.DesignProspective, randomized, case series.SettingA university hospital operating suite and surgical intensive care unit.PatientsSixty patients undergoing lower extremity vascular surgery.InterventionsPatients were randomized to receive either epidural anesthesia/epidural opiate analgesia (regional anesthesia) or general anesthesia/intravenous patient-controlled analgesia (general anesthesia).Measurements and Main ResultsAnesthesia was managed according to a prospectively designed protocol. Hemodynamic parameters and plasma catecholamine concentrations were determined at specific intraoperative and postoperative time points. Intraoperative and postoperative urine samples were collected and analyzed for free cortisol concentrations. Outcomes evaluated were cardiac (nonfatal myocardial infarction and cardiac death) and surgical (graft occlusion). Mean arterial pressure during emergence from anesthesia and in the early postoperative period correlated positively with plasma norepinephrine concentration (p less than .01). In addition, plasma catecholamine concentrations were higher in patients with postoperative hypertension. Plasma norepinephrine concentrations at the time of emergence from anesthesia and postoperatively were also higher in patients requiring repeat surgery for graft revision, thrombectomy, or amputation (p less than .05). Multivariate analysis indicated that the norepinephrine concentration at the time of emergence, but not type of anesthesia, correlated with reoperation for graft occlusion, suggesting that the previously reported beneficial effect of regional anesthesia may be due to modulation of the stress response. Myocardial infarction or cardiac death occurred in three patients. These patients had markedly increased catecholamine concentrations.ConclusionsThe catecholamine response to lower extremity vascular surgery contributes to the development of postoperative hypertension and may also be important in the development of thrombotic complications.(Crit Care Med 1995; 23:1954-1961)

ISSN:0090-3493    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

ObjectivesTo test whether dopamine infusion improves oxygen delivery (DO sub 2) and oxygen uptake (VO2) in hyperdynamic septic shock patients stabilized by adequate volume and dobutamine alone, or by the combination of dobutamine and norepinephrine.DesignProspective clinical trial of two patient groups. Group 1 (n equals 15) was stabilized with dobutamine, and group 2 (n equals 10) was stabilized with dobutamine and norepinephrine.SettingIntensive care unit in a university hospital.PatientsTwenty-five postoperative, hyperdynamic septic shock patients.InterventionsThe stabilizing catecholamine infusion was replaced in a stepwise manner by dopamine to achieve a similar mean arterial pressure (dopamine doses: group 1, mean 22 plus minus 15 micro gram/kg/min [range 6 to 52]; and group 2, mean 57 plus minus 41 micro gram/kg/min [range 15 to 130]).Measurements and Main ResultsA complete hemodynamic profile was performed with oxygen transport-related variables at baseline, after replacement by dopamine, and after resetting to the original catecholamine infusion. The change to dopamine resulted in increases in cardiac index (group 1: 20% [p less than .01]; group 2: 33% [p less than .01]), and DO2(group 1: 19% [p less than .01]; group 2: 27% [p less than .01]). However, VO2, whether directly measured from the respiratory gases or calculated by the cardiovascular Fick principle, did not change in both groups with dopamine, while the oxygen extraction ratio decreased significantly in both groups with dopamine. Heart rate, pulmonary artery occlusion pressure, and pulmonary shunt fraction all increased with dopamine. PaO2decreased, but oxygen saturation remained stable in both groups with dopamine.ConclusionsShort-term dopamine infusion in hyperdynamic septic shock patients, despite producing higher global DO2, was not superior to dobutamine or the combination of dobutamine and norepinephrine infusion.(Crit Care Med 1995; 23:1962-1970)

ISSN:0090-3493    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

ObjectiveTo assess the relative contributions of changes in vascular tone and changes in cardiac function to hemodynamic recovery from septic shock.DesignCase series, observational study.SettingMultidisciplinary department of intensive care in an academic hospital.PatientsSixty-seven patients with septic shock (prolonged hypotension, signs of tissue hypoperfusion, signs of sepsis, suspected source of infection, or documented bacteremia). In addition to the antibiotic therapy and the removal of the source of sepsis whenever possible, each patient received intravenous fluids and vasoactive agents (dopamine, norepinephrine, and dobutamine). Each patient was also treated with mechanical ventilation. Twenty-four (36%) patients survived their intensive care unit course.InterventionsHemodynamic measurements were obtained at baseline, after initial resuscitation (as soon as apparent hemodynamic stability was achieved), after 12 hrs, and after 24 hrs.Measurements and Main ResultsThere were no significant differences in hemodynamic or oxygen-derived variables at baseline between the survivors and the nonsurvivors. During the initial resuscitation period, only the survivors demonstrated a significant increase in mean arterial pressure (from 69 plus minus 17 to 82 plus minus 18 mm Hg; p less than .02) and left ventricular stroke work index (from 25.2 plus minus 11.0 to 35.5 plus minus 19.4 g centered dot m/m2; p less than .05). The increases in cardiac index and systemic vascular resistance were greater in the survivors than in the nonsurvivors, but the differences did not reach statistical significance. Study of the left ventricular function curves indicated an improvement of left ventricular function in the survivors but not in the nonsurvivors.ConclusionAn early improvement in left ventricular function is a hallmark of the survivors from septic shock.(Crit Care Med 1995; 23:1971-1975)

ISSN:0090-3493    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

ObjectiveTo determine the influence of a selective, sterile central nervous system surgery on immune reactivity, particularly whether a decrease of monocytic human leukocyte antigen-DR expression, indicating immunodepression, occurs after neurosurgery and if this measurement is useful for identification of patients with a high risk of infection.DesignProspective study.SettingDepartment of neurosurgery and intensive care unit in a university hospital.Patients and InterventionsBlood samples were obtained from 46 patients at least once during the first 3 days after undergoing sterile central nervous system surgery. Fourteen of these patients developed infectious complications as defined by clinical and microbiological criteria. In ten of 46 patients, paired samples of blood and cerebrospinal fluid were collected from a ventricle drain at the following times: 1 day before surgery; several times on the day of surgery; and every day after surgery for at least 6 days.Measurements and Main ResultsMonocytic human leukocyte antigen-DR expression, as measured by flow cytometry on days 1 through 3 after surgery in 46 patients, was lower in 14 patients who developed infection after neurosurgery (p less than .0001). In all ten closely monitored patients, monocytic human leukocyte antigen-DR expression decreased temporarily after surgery. Of these patients, only one patient showed a persistent and considerably decreased monocytic human leukocyte antigen-DR expression. This patient was the only patient in this subgroup who developed sepsis syndrome. In order to assess whether the monocytic human leukocyte antigen-DR decrease was associated with a preceding inflammatory response, local and systemic concentrations of interleukin (IL)-1 beta, IL-6, IL-8, tumor necrosis factor-alpha, and interferon-gamma were measured in this subgroup. These cytokines were not detectable in plasma during the first days after surgery. In contrast, considerable increases of IL-6 and IL-8 concentrations were detectable in cerebrospinal fluid within hours after surgery.ConclusionsA decrease of monocytic human leukocyte antigen-DR expression occurs after neurosurgery and is associated with a preceding, strong, intracranial (but not systemic) inflammatory response. A very low monocytic human leukocyte antigen-DR expression (less than 30% positive monocytes) suggests the possibility of infection. Measurement of monocytic human leukocyte antigen-DR expression could help to detect patients with a high risk of infection after neurosurgery. Our results suggest that even sterile central nervous system surgery may contribute to general immunodepression. The local intracranial inflammatory response may be involved in this process.(Crit Care Med 1995; 23:1976-1983)

ISSN:0090-3493    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

ObjectivesTo evaluate instantaneous blood flow variations in the compression and relaxation phases of cardiopulmonary resuscitation (CPR) and the effect of epinephrine administration.DesignProspective, randomized, controlled trial.SettingExperimental laboratory in a university hospital.SubjectsTwenty-two anesthetized piglets.InterventionsA tracheostomy was performed and arterial, central venous, and pulmonary arterial catheters were inserted, followed by thoracotomy with placement of pulmonary arterial, aortic, and left anterior descending coronary arterial (extended study group) flow probes and a left atrial catheter. Ventricular fibrillation for 2 mins was followed by 10 mins of either open-chest (n equals 10) or closed-chest (n equals 12) CPR. Seven minutes after the initiation of CPR, all piglets received 0.5 mg of epinephrine iv; at 12 mins, direct current shocks were applied.Measurements and Main ResultsOpen-chest CPR generated greater systemic perfusion pressure than closed-chest CPR, especially during the relaxation phase, resulting in greater mean blood flow. With both open- and closed-chest CPR, antegrade pulmonary arterial and aortic blood flow occurred during compression, whereas antegrade left anterior descending coronary arterial blood flow occurred during relaxation. During relaxation, retrograde flow was found in the pulmonary artery and aorta. During compression, retrograde flow was found in the left anterior descending coronary artery. The administration of epinephrine had the following effects: a) increased the systemic perfusion pressure more during open- than closed-chest CPR; b) increased the systemic relaxation perfusion pressure more than the compression perfusion pressure; c) decreased mean pulmonary arterial and aortic blood flow, but substantially increased the mean left anterior descending coronary artery blood flow; and d) reduced the retrograde flow in the left anterior descending coronary artery.ConclusionsOpen-chest CPR generated greater systemic perfusion pressure and blood flow than closed-chest CPR. Epinephrine increased left anterior descending coronary artery blood flow but decreased total cardiac output, such that cerebral perfusion might be endangered. This problem will be studied separately.(Crit Care Med 1995; 23:1984-1996)

ISSN:0090-3493    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

ObjectivesCan the hepatic structural deterioration that occurs during peritonitis be attenuated by increasing cardiac output and oxygen consumption (VO2)? Do the agents used to achieve these increases have any characteristic affects on these hepatic structural changes?DesignRandomized, prospective, observational animal study.SettingResearch laboratory of a university medical school.SubjectsTwenty-five Middle White adolescent pigs, weighing 25 to 30 kg, divided into five groups.InterventionsA thermodilution flotation catheter was advanced into the pulmonary artery. Additional catheters were inserted into the jugular, portal, and hepatic veins, and into the femoral artery. Ultrasound flow probes were placed around the portal vein and the hepatic artery. A metabolic cart was attached to the ventilator. Baseline measurements were made and cardiac output was increased by more than 25% by administering either dobutamine (10 micro gram/min), dopexamine (10 micro gram/kg/min), or colloid. A control group had its cardiac output maintained at its baseline value. Peritonitis was induced in the four groups by contamination with cecal content and maintained for 6 hrs. Hepatic tissue was then removed for ultrastructural analysis and the animals were killed.Measurements and Main ResultsBefore infection, cardiac output, VO2, and hepatic blood flow were increased in the three treatment groups. In the dobutamine and dopexamine groups, oxygen delivery increased, but decreased in the volume group. Mean arterial pressure increased in the dobutamine and dopexamine groups, but in the volume group, mean arterial pressure was maintained.Six hours after infection, cardiac output and VO sub 2 had further increased in the dobutamine and volume groups, but both variables had decreased in the dopexamine group. After infection in the control group, cardiac output had decreased, although oxygen delivery and VO2increased. There were no significant differences between hepatic hemodynamic or oxygen transport variables in any of the groups during the infection period. Hepatic ultrastructure was well maintained in the dopexamine group, while considerable deterioration was seen in the volume and control groups. In the dobutamine group, hepatic deterioration was greater than in the other three groups.ConclusionsIncreasing cardiac output and VO2before and during infection was only protective when dopexamine was administered. Dobutamine infusion was associated with greater hepatic deterioration than that effect seen in either the control or volume groups.(Crit Care Med 1995; 23:1997-2007)

ISSN:0090-3493    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

ObjectivesTo determine the influence of ketamine on endotoxin-induced leukocyte adherence and venular microhemodynamics.DesignRandomized, controlled trial.SettingExperimental laboratory.SubjectsThirty male Wistar rats.InterventionsThe rats were pretreated with ketamine (10 mg/kg iv) or 0.9% saline, and both groups were given endotoxin (Escherichia coli lipopolysaccharide; 5 mg/kg iv). The control group received two doses of 0.9% saline.Measurements and Main ResultsThe rates of leukocyte adherence and changes in microhemodynamics were monitored in rat mesenteric venules, using in vivo video microscopy. The number of adherent leukocytes was determined on-line in 10-min intervals from 60 mins before until 2 hrs after endotoxin administration. Venular diameters, red blood cell velocity, volumetric blood flow, and the venular wall shear rate were monitored before and at 10, 30, and 60 mins after endotoxin exposure.A 6.3-fold increase in the number of adherent leukocytes was observed 10 mins after administration of endotoxin when compared with control animals (5.87 plus minus 0.69 vs. 0.93 plus minus 0.21 adherent cells/100 micro meter; p less than .001). This increase remained unchanged for 120 mins. In ketamine-pretreated rats, a 2.6-fold increase in leukocyte adherence occurred during the first 20 mins after endotoxin exposure (2.40 plus minus 0.46 vs. 0.93 plus minus 0.21 adherent cells/100 micro meter; p less than .01). However, no difference in the number of adherent leukocytes between ketamine-pretreated and control animals was found after this 20-min period. In animals of the control group, no increase in leukocyte adherence occurred during the entire observation time. Diameters of mesenteric venules did not change after endotoxin exposure in any of the groups. Red blood cell velocity and venular blood flow in the endotoxin-treated groups decreased 10 mins after the injection of endotoxin when compared with controls, but these values did not show any difference when they were compared between ketamine and saline-pretreated animals. Similarly, venular wall shear rate in the endotoxin-treated groups decreased 10 and 30 mins after injection of endotoxin. However, no significant difference occurred between ketamine and saline-pretreated animals.ConclusionsPretreatment with ketamine attenuates endotoxin-induced leukocyte adherence by a shear rate-independent mechanism, suggesting reduced expression of adhesion molecules. These results indicate that ketamine exerts an anti-inflammatory effect, which might be beneficial in septic patients.(Crit Care Med 1995; 23:2008-2014)

ISSN:0090-3493    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

ObjectiveTo assess the applicability of a new technology in neonates. Transtracheal Doppler and extravascular Doppler determinations of stroke volume and cardiac output were compared with thermodilution measurements at various states of volume loading in an animal model.DesignProspective, descriptive study.SettingAnimal research laboratory at a university medical center.SubjectsFourteen newly weaned piglets, weighing 2.8 to 6.5 kg.InterventionsDoppler probes were placed on the endotracheal tube tip (transtracheal Doppler) and directly on the aortic adventitia (extravascular Doppler). A 4-Fr thermodilution catheter was inserted in the pulmonary artery. Stroke volume and cardiac output determinations were recorded at baseline, after a 15-mL/kg volume load and after successive 15-mL/kg blood withdrawals to exsanguination or a systolic blood pressure of less than 20 mm Hg.Measurements and Main ResultsTranstracheal and extravascular Doppler measurements of cardiac output were not significantly different from thermodilution at any physiologic state. These techniques were able to measure stroke volumes and cardiac outputs at the low levels seen in severe hemorrhagic shock.ConclusionsTranstracheal Doppler and extravascular Doppler measurements of cardiac output compare favorably with thermodilution. These methods effectively followed trends from alterations in intravascular volume, even at very high heart rates and small stroke volumes. Transtracheal Doppler and extravascular Doppler should yield useful information in critically ill neonatal patients, where data regarding stroke volume and cardiac output may be useful in clinical management.(Crit Care Med 1995; 23:2015-2022)

ISSN:0090-3493    

出版商:OVID    

年代:1995

数据来源: OVID