摘要:

ObjectiveTo determine the influence of pentoxifylline on endothelial-associated coagulation.DesignProspective, randomized, placebo-controlled study.SettingA surgical intensive care unit of a university hospital.PatientsConsecutive patients (n equals 60) with trauma or sepsis secondary to major (nontrauma) surgery. All patients received controlled mechanical ventilation.InterventionsAccording to a randomized sequence, the patients either received pentoxifylline continuously over 5 days (1.5 mg/kg/hr iv) (trauma-pentoxifylline group [n equals 15], sepsis-pentoxifylline group [n equals 15]) or saline solution as placebo (trauma-control group [n equals 15], sepsis-control group [n equals 15]).Measurements and Main ResultsIn addition to the standard coagulation screen, thrombomodulin, protein C, (free) protein S, and thrombin-antithrombin plasma concentrations were measured by enzyme-linked immunosorbent assays. Intensive care therapy, hemodynamics, and changes of Acute Physiology and Chronic Health Evaluation II score were comparable for pentoxifylline-treated and nontreated patients. An average dose of 2.5 g/day of pentoxifylline (range 2.2 to 2.9) was infused into the pentoxifylline-treated patients. At baseline, plasma thrombomodulin concentrations were higher in the septic patients than in the trauma patients. Thrombomodulin plasma concentrations increased significantly more in the control patients (trauma: from 38.9 plus minus 10.5 to 59.9 plus minus 10.1 ng/mL; sepsis: from 49.7 plus minus 12.1 to 72.3 plus minus 11.2 ng/mL) than in the pentoxifylline-treated patients (trauma: from 37.9 plus minus 11.9 to 50.2 plus minus 9.2 ng/mL; sepsis: from 51.9 plus minus 10.1 to 63.3 plus minus 10.2). Starting from similar baseline values, protein C concentration increased significantly more in the sepsis-pentoxifylline patients (from 52.0 plus minus 11.1% to 69.1 plus minus 11.1%) than in the untreated septic patients (from 50.1 plus minus 10.0% to 52.5 plus minus 9.5%). There were no significant differences between the pentoxifylline-treated and nontreated groups for protein S and thrombin-antithrombin concentrations. Standard coagulation parameters (fibrinogen, activated partial thromboplastin time, antithrombin III) did not differ between these groups either.ConclusionsContinuous intravenous administration of pentoxifylline for 5 days beneficially influenced the thrombomodulin/protein C/protein S system in both the trauma and septic patients.(Crit Care Med 1996; 24:940-946)

ISSN:0090-3493    

出版商:OVID    

年代:1996

数据来源: OVID

摘要:

ObjectiveTo evaluate the influence of the alpha2-adrenergic receptor agonist clonidine on creatinine clearance as a measure of renal function.DesignProspective, double-blind, randomized, placebocontrolled clinical trial.SettingUniversity hospital.PatientsPatients undergoing coronary artery bypass graft surgery (n equals 48) with normal risk.InterventionsAdministration of clonidine (4 micro gram/kg iv) or placebo 1 hr before induction of anesthesia.Measurements and Main ResultsInduction and maintenance of anesthesia (etomidate, midazolam, and fentanyl) and cardiopulmonary bypass technique (nonpulsatile, normothermic, intermittent cold blood cardioplegia) were standardized in all patients. The night before surgery and the first and third night after surgery, creatinine clearance was calculated from a 12-hr urine collection period. Venous blood samples for determination of plasma anti-diuretic hormone (ADH) concentrations were taken the evening before surgery, immediately before induction of anesthesia and the evening after surgery (n equals 16). Arterial catecholamine plasma concentrations were determined (high-performance liquid chromatography) before induction, 15 mins after induction of anesthesia, immediately after sternotomy, before initiation of cardiopulmonary bypass, as well as 5, 15, and 30 mins after initiation of cardiopulmonary bypass (n equals 16).The total amount of anesthetics, infusions, transfusions, diuresis, and blood loss was not different between the groups. Creatinine clearance decreased over the first postoperative night from 98 plus minus 18 (preoperatively) to 68 plus minus 19 mL/min (p less than .05) in placebo-treated patients. Creatinine clearance remained unchanged in clonidine-treated patients (90 plus minus 19 [preoperatively] to 92 plus minus 17 mL/min). There was a significant difference in creatinine clearance between the groups during the first postoperative night (p less than .05; Mann-Whitney U test). In the third postoperative night, mean creatinine clearance of both groups was not different (75 plus minus 31 vs. 86 plus minus 28 mL/min). ADH concentrations were not different between the groups at any time, while plasma catecholamine concentrations were always significantly lower in clonidine-treated patients.ConclusionsPreoperative treatment with clonidine (4 micro gram/kg) prevents the deterioration of renal function after cardiac surgery. This effect might be due to a clonidine-induced reduction in the sympathetic nervous system response to coronary artery bypass graft surgery.(Crit Care Med 1996; 24:947-952)

ISSN:0090-3493    

出版商:OVID    

年代:1996

数据来源: OVID

摘要:

ObjectiveTo evaluate outcome from severe acute traumatic diffuse brain swelling, in relation to early patterns of global cerebral extraction of oxygen.DesignProspective, interventional study.SettingNeuroscience intensive care unit of a university hospital.PatientsAdults (n equals 205) with acute, essentially isolated brain trauma (predominantly diffuse brain swelling), undergoing routine early monitoring of cerebral extraction of oxygen and intracranial pressure, along with other monitoring modalities.InterventionsRoutine neuroemergency procedures.Measurements and Main ResultsCerebral extraction of oxygen (arteriojugular oxyhemoglobin saturation difference) was measured in each patient, early in the acute phase (2 to 8 hrs postinjury). Outcome at 6 months postinjury was significantly better in patients with initially increased cerebral extraction of oxygen (more than 42%) than in those patients with normal (24% to 42%) or decreased (less than 24%) values. In contrast, no significant differences were found among these three groups with respect to age, initial Glasgow Coma Scale score, intracranial pressure, cerebral perfusion pressure, Paco2, total hemoglobin content, and time from injury when the initial measurements were performed.ConclusionsInitially increased cerebral extraction of oxygen appears to indicate global cerebral viability rather than cerebral ischemia in patients with acute traumatic diffuse brain swelling.(Crit Care Med 1996; 24:953-956)

ISSN:0090-3493    

出版商:OVID    

年代:1996

数据来源: OVID

摘要:

ObjectiveTo determine the accuracy of a new, portable, battery-powered blood gas analyzer when used by nonlaboratorytrained clinicians in the critical care setting.DesignProspective analysis of blood samples from critically ill patients.SettingLarge tertiary critical care unit.PatientsHeterogeneous group of medical and surgical critically ill patients.InterventionsNone.Measurements and Main ResultsTwo hundred thirty-nine split blood samples from intensive care patients were analyzed by clinicians in the critical care environment using a new, portable, battery-powered blood gas analyzer (Immediate Response Mobile Analyzer [IRMA Trademark], Diametrics Medical, St. Paul, MN). Near-patient measurements were compared with measurements obtained by laboratory technologists using an IL-1312 blood gas analyzer (Instrumentation Laboratories, Lexington, MA) in an established near-patient critical care laboratory. Precision and coefficients of variation were also determined using repeated testing of quality control samples at three levels of pH, PO2, and PCO2.There was good agreement between IRMA determinations and the laboratory. Correlation coefficients ranged from 0.96 to 0.99. Bias and precision (plus minus 2 SD), respectively, were 0.02 and 0.036 units for pH, minus 0.3 torr (minus 0.04 kPa) and 7.2 torr (0.96 kPa) for PCO2, and minus 3.9 torr (minus 0.52 kPa) and 13.8 torr (1.8 kPa) for PO2. Precision on repeated testing of quality control samples ranged from 0.022 to 0.04 units for a pH of 7.2 to 7.6, 1.2 to 4.6 torr (0.16 to 0.61 kPa) for a PCO sub 2 of 20 to 60 torr (2.7 to 8 kPa), and 3.0 to 7.4 torr (0.40 to 0.99 kPa) for a PO2of 70 to 160 torr (9.3 to 21.3 kPa). Coefficients of variation ranged from 0.15% to 0.28% for a pH of 7.2 to 7.6, 2.0% to 3.7% for a PCO2of 20 to 60 torr (2.7 to 8.0 kPa), and 1.7% to 3.6% for a PO2of 70 to 160 torr (9.3 to 21.3 kPa). Mean turnaround time was 16.5 plus minus 10.1 mins for the near-patient laboratory and 2 plus minus 0.5 mins for IRMA.ConclusionsIRMA is accurate and reproducible when used in the clinical setting by nonlaboratory-trained individuals. Nonlaboratory-trained individuals can obtain laboratory results in the critical care setting comparable with the results obtained by trained laboratory technologists. Bedside laboratory testing decreases turnaround time compared with a near-patient laboratory.(Crit Care Med 1996; 24:957-962)

ISSN:0090-3493    

出版商:OVID    

年代:1996

数据来源: OVID

摘要:

ObjectiveIntensive care resources are both scarce and costly in South Africa. We set out to ascertain whether human immunodeficiency virus (HIV) status affects the spectrum of disease and the prognosis in children treated in pediatric intensive care units (ICUs).DesignA prospective, case-controlled study.SettingThe pediatric ICU at King Edward VIII Hospital, Durban, South Africa.PatientsHIV-positive cases were classified as ``acquired immunodeficiency syndrome,'' ``symptomatic HIV,'' and ``HIV-unrelated diseases.'' Controls were matched for age, race, gender, severity of disease, and admitting diagnosis.Measurements and Main ResultsThe clinician was blinded to the serostatus of patients. Informed consent and Ethics Committee approval were obtained for HIV testing and the study. Outcome measures were the duration of intermittent positive-pressure ventilation and ICU stay, maximum ventilatory requirements, infectious complications, and mortality. There were 11 cases of acquired immune deficiency syndrome (AIDS), 24 cases of symptomatic HIV, and 13 cases of HIV-unrelated diseases. Mortality rates for the three groups were as follows: 100% in patients with AIDS compared with 55% in their controls (p less than .01); 38% in patients with symptomatic HIV and 46% in controls; and 54% in patients with HIV-unrelated disease as against 46% in controls. Cytomegalovirus and Pneumocystis carinii infections were significantly increased (p less than .01, p less than .002, respectively) in patients with AIDS as compared with controls. Outcome measures were similar in those patients with symptomatic HIV and those patients with HIV-unrelated diseases, as compared with their respective controls.ConclusionsOutcome in children with AIDS admitted to the pediatric ICU was significantly worse than the outcome in HIV-uninfected children. However, the number of AIDS patients studied was small. HIV antibody-positive children without AIDS do as well as uninfected controls. Ethics committees in resourceconstrained countries may be assisted by such data when making difficult decisions on the admissions of HIV-infected patients to pediatric ICU facilities.(Crit Care Med 1996; 24:963-967)

ISSN:0090-3493    

出版商:OVID    

年代:1996

数据来源: OVID

摘要:

ObjectiveTo assess the influence of private attending physician status on the withdrawal of life-sustaining interventions among patients dying within a medical intensive care unit (ICU).DesignRetrospective cohort analysis.SettingAn academic tertiary care center.PatientsOne hundred fifty-nine consecutive patient deaths occurring in the medical ICU during a 12-month period.InterventionsNone.Measurements and Main ResultsWithdrawal of life-sustaining interventions (i.e., mechanical ventilation, dialysis, and/or vasopressors), duration of mechanical ventilation, length of intensive care unit stay, medical care costs, and patient charges were recorded.Life-sustaining interventions were actively withdrawn from 69 (43.4%) patients prior to death. Patients without a private attending physician were significantly more likely to undergo the withdrawal of life-sustaining interventions compared with patients having a private attending physician (odds ratio equals 2.5; 95% confidence interval equals 1.8, 3.6, respectively; p equals .005). A correlation was found between the possession of private health insurance and private attending physician status (r2equals .39, p less than .001). Multiple logistic regression analysis was subsequently used to control for demographic factors and severity of illness. Three independent predictors for the withdrawal of life-sustaining interventions were identified in this patient cohort (p less than .05): having a planned therapeutic trial of life-sustaining interventions outlined in the medical record (adjusted odds ratio equals 9.4; 95% confidence interval equals 5.6 to 15.6; p less than .001); lack of a private attending physician (adjusted odds ratio equals 4.4; 95% confidence interval equals 2.9 to 6.5; p less than .001); and the presence of clearly defined advance directives regarding patient preferences for medical care (adjusted odds ratio equals 3.6; 95% confidence interval equals 2.3 to 5.7; p equals .005). Patients with private attending physicians had significantly greater medical care costs and medical care charges compared with patients without a private attending physician.ConclusionAmong patients dying within a medical ICU, those patients without a private attending physician are more likely to undergo the active withdrawal of life-sustaining interventions.(Crit Care Med 1996; 24:968-975)

ISSN:0090-3493    

出版商:OVID    

年代:1996

数据来源: OVID

摘要:

ObjectivesThere is increased awareness of imposed work of breathing contributing to apparent ventilatory dependency. This study evaluates the impact of tachypnea as an indicator of ventilatory failure during a room air-5 cm H2O continuous positive airway pressure, spontaneous breathing, preextubation trial when associated with increased imposed work of breathing.DesignProspective, descriptive, 1-yr data collection.SettingUniversity hospital trauma intensive care unit (ICU).PatientsMechanically ventilated trauma ICU patients surviving to discharge.InterventionPatients were weaned to minimal mechanical ventilator support and underwent a 20-min room air-continuous positive airway pressure preextubation trial (FIO2equals 0.21, continuous positive airway pressure equals 5 cm H2O [0.5 kPa]). When passed (PaO2more than equals 55 torr [more than equals 7.3 kPa], PaCO2less than equals 45 torr [less than equals 6.0 kPa] with prior eucapnea, arterial pH more than equals 7.35, respiratory rate less than equals 30 breaths/min), extubation followed. If patients failed due to hypoxemia, ventilatory support resumed. If tachypnea was the reason for failure, work of breathing was measured. If patient work of breathing was less than equals 1.1 joule/L, extubation proceeded despite tachypnea. If patient work of breathing was more than 1.1 joule/L, imposed work of breathing was measured, and if residual ``physiologic'' work of breathing (patient work of breathing minus imposed work of breathing) was less than equals 0.8 joule/L, patients were extubated.Measurements and Main ResultsOf 589 extubations, 105 (18%) were classified as false negatives based on a preextubation rate of more than 30 breaths/min. Of these, 97 were successfully extubated despite tachypnea ranging from 32 to 56 breaths/min, when combined with either a patient work of breathing less than equals 1.1 joule/L or physiologic work of breathing less than equals 0.8 joule/L. The rate of extubation failure within 72 hrs was 7.8% (8/105) in the tachypneic group, compared with 7.9% (38/484) for those patients with a respiratory rate of less than equals 30 breaths/min. Some of the stimulus for the tachypnea was possibly due to increased imposed work of breathing, as the increased respiratory rate usually abated within 18 hrs after extubation. The reliance on a respiratory rate of less than equals 30 breaths/min as an absolute preextubation criterion would have resulted in a sensitivity of 82%, a specificity of 17%, a positive predictive value of 92%, a negative predictive value of 8%, and an overall accuracy of 77%. The average duration of mechanical ventilation during the study period decreased by 2 days, from 8.6 to 6.3 days (p equals .03).ConclusionsTachypnea as a marker of respiratory distress is sensitive, but is not sufficiently specific to be used as a criterion in preextubation trials. Reliance on tachypnea as a preextubation trial failure criterion is likely to prolong intubation and ventilatory support for a large number of patients. Patient risks, determined by the extubation failures and reintubation rate, are the same.(Crit Care Med 1996; 24:976-980)

ISSN:0090-3493    

出版商:OVID    

年代:1996

数据来源: OVID

摘要:

ObjectivesTo determine the presenting features, prognostic factors, course, and outcome of critically ill patients with systemic lupus erythematosus admitted to the intensive care unit (ICU).DesignRetrospective patient record review.SettingTwo academic teaching hospitals.PatientsAll patients with systemic lupus erythematosus admitted to the ICUs between January 1982 and July 1993.Measurements and Main ResultsThere were 28 female and two male patients. Fifteen patients were white, 11 patients were black, and four patients were Asian. The median age was 29 yrs. The reasons for admission to the ICU were multifactorial. However, most patients were admitted for infective, renal, cardiac, or coagulation complications. Despite aggressive management, 16 (53%) patients died in the ICU or shortly after discharge. The median ICU survival rate (admission to death) was 22 days. The only pretreatment factor that predicted a poor outcome was the presence of renal involvement due to systemic lupus erythematosus.ConclusionsOur study suggests that patients with systemic lupus erythematosus admitted to an ICU often have florid disease manifestations with multifactorial reasons precipitating the admission. The prognosis for such patients is poor, particularly in the presence of renal involvement.(Crit Care Med 1996; 24:981-984)

ISSN:0090-3493    

出版商:OVID    

年代:1996

数据来源: OVID

摘要:

ObjectiveTo clarify the effect of hypoxia on bacteria-enterocyte interactions.DesignRandomized.SettingResearch laboratory.SubjectsEnteric bacteria and cultured human intestinal epithelial cells, HT-29 cells.InterventionsThe effect of hypoxia on bacterial internalization and intracellular survival was studied, using enterocytes cultured for 21 days in either 20%, 10%, or 5% oxygen. The effect of bacterial growth conditions on bacterial internalization by enterocytes was studied, using bacterial cells in either the log phase or stationary phase of aerobic growth, and using bacterial cells in stationary phase, grown either under low oxygen conditions or under anaerobic conditions.Measurements and Main ResultsIndividual strains of enteric bacteria were incubated with HT-29 cells for 1 hr. Numbers of internalized bacteria were subsequently quantified after enterocyte lysis. Bacterial growth conditions (anaerobic vs. aerobic and log-phase vs. stationary-phase bacterial cells) had no noticeable effect on the numbers of Salmonella typhimurium, Proteus mirabilis, and Escherichia coli internalized by enterocytes. Enterocytes cultivated in 20%, 10%, or 5% oxygen were more than 95% viable. Enterocytes cultivated in 20% oxygen were confluent, but those enterocytes cultivated in hypoxia were not confluent and were fewer in number compared with enterocytes cultivated in normoxia. Compared with enterocytes grown in normoxia, enterocytes cultivated in 5% and 10% oxygen internalized greater numbers of each of seven strains of enteric bacteria, including Listeria monocytogenes (two strains), Enterococcus faecalis (two strains), and P. mirabilis, E. coli (two strains), with statistically significant increases noted for five of these seven bacterial strains. Intracellular survival of L. monocytogenes and P. mirabilis was assayed. Both species survived intracellularly for 22 hrs, with no noticeable differences in the numbers of intracellular bacteria recovered from enterocytes cultivated in 20%, 10%, and 5% oxygen.ConclusionThese in vitro results suggest that augmented bacterial endocytosis by enterocytes might at least partially explain the increased frequency of bacterial translocation associated with tissue ischemia.(Crit Care Med 1996; 24:985-991)

ISSN:0090-3493    

出版商:OVID    

年代:1996

数据来源: OVID

摘要:

ObjectiveTo investigate the functional and metabolic changes in the myocardium after successful resuscitation from cardiac arrest.DesignProspective, randomized, sham-controlled study.SettingAnimal laboratory at a university center.SubjectsDomestic pigs.InterventionsElectric induction of ventricular fibrillation by alternating current delivered to the right ventricular endocardium through a pacing electrode. Electric defibrillation was attempted after an interval of 12 mins of ventricular fibrillation, which included 4 mins of untreated ventricular fibrillation and 8 mins of precordial compression in 13 animals, seven of which were successfully resuscitated. Seven additional animals were randomized to serve as ``sham'' controls, in which cardiac arrest was not induced.Measurements and Main ResultsLeft ventricular pressure-volume relationships utilizing the conductance method were obtained in conjunction with conventional hemodynamic and metabolic measurements at baseline and during a 6-hr interval after successful cardiac resuscitation. Progressive and striking increases in left ventricular volumes were observed after successful cardiac resuscitation. The end-diastolic volume increased from a prearrest level of 89 plus minus 21 mL to a maximum of 154 plus minus 53 mL (p less than .05) at 360 mins after successful resuscitation. The time-coincident end-systolic volume increased from 54 plus minus 21 to 126 plus minus 54 mL (p less than .05), such that the ejection fraction was reduced from 0.41 plus minus 0.10 to 0.20 plus minus 0.07 (p less than .05). Ventricular dilation was associated with marked reductions in stroke volume and ventricular work. However, compensatory increases in heart rate maintained cardiac output at levels that sustained adequate systemic oxygen delivery. The slope of the end-systolic pressure-volume relationships progressively decreased from 5.04 plus minus 1.88 to 2.00 plus minus 0.57 mm Hg/mL (p less than .05) at 360 mins after successful resuscitation. The volume intercept at left ventricular pressure of 100 mm Hg increased from 43 plus minus 19 to 94 plus minus 51 mL (p equals .03). Both the decrease in the slope and the increase in the volume intercept were characteristic of progressive impairment in contractile function. The rate of left ventricular pressure decrease was unchanged. Accordingly, no substantial changes in lusitropic properties were identified. Despite large increases in end-diastolic volume, the end-diastolic pressure remained unchanged.ConclusionPostresuscitation myocardial dysfunction in this animal model was characterized by impaired contractile function, decreased work capability, and ventricular dilation.(Crit Care Med 1996; 24:992-1000)

ISSN:0090-3493    

出版商:OVID    

年代:1996

数据来源: OVID