摘要:

ObjectiveClinical trials of therapies for sepsis have been mostly unsuccessful in impacting mortality. This may be partly due to the use of insensitive mortality end points. We explored whether modeling survival was more sensitive than traditional end points in detecting mortality differences in cohorts of patients with sepsis.DesignPatients were stratified into sevena prioridefined paired subgroups that reflected high and low mortality risk according to known clinical risk factors. We fitted an exponential survival model to the high- and low-risk cohort of each subgroup, providing estimates of the rate of dying, long-term survival, and excess day 1 mortality. Mortality in the high- and low-risk cohorts in each subgroup was compared using model parameters, fixed-point mortality, and Kaplan-Meier survival analysis.SettingEight intensive care units within a university teaching institution.PatientsOne hundred thirty patients with severe sepsis or suspected Gram-negative bacteremia.InterventionsNone.Measurements and Main ResultsOverall mortality of the cohort was 58.5% at 28 days. The survival of the entire cohort was well described by an exponential model (r2= .99). Modeling identified differences in high- and low-risk cohorts in five of the seven paired subgroups, while conventional end-points only detected differences in 2.ConclusionsModeling survival was more sensitive than conventional end-points in identifying survival differences between high- and low-risk subgroups. We encourage further evaluation of modeling in the search for more sensitive mortality end points.

ISSN:0090-3493    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

ObjectiveDeliberate elevation of Paco2(therapeutic hypercapnia) protects against lung injury induced by lung reperfusion and severe lung stretch. Conversely, hypocapnic alkalosis causes lung injury and worsens lung reperfusion injury. Alterations in lung surfactant may contribute to ventilator-associated lung injury. The potential for CO2to contribute to the pathogenesis of ventilator-associated lung injury at clinically relevant tidal volumes is unknown. We hypothesized that: 1) hypocapnia would worsen ventilator-associated lung injury, 2) therapeutic hypercapnia would attenuate ventilator-associated lung injury; and 3) the mechanisms of impaired compliance would be via alteration of surfactant biochemistry.DesignRandomized, prospective animal study.SettingResearch laboratory of university-affiliated hospital.SubjectsAnesthetized, male New Zealand Rabbits.InterventionsAll animals received the same ventilation strategy (tidal volume, 12 mL/kg; positive end-expiratory pressure, 0 cm H2O; rate, 42 breaths/min) and were randomized to receive Fico2of 0.00, 0.05, or 0.12 to produce hypocapnia, normocapnia, and hypercapnia, respectively.Measurements and Main ResultsAlveolar-arterial oxygen gradient was significantly lower with therapeutic hypercapnia, and peak airway pressure was significantly higher with hypocapnic alkalosis. However, neither static lung compliance nor surfactant chemistry (total surfactant, aggregates, or composition) differed among the groups.ConclusionsAt clinically relevant tidal volume, CO2modulates key physiologic indices of lung injury, including alveolar-arterial oxygen gradient and airway pressure, indicating a potential role in the pathogenesis of ventilator-associated lung injury. These effects are surfactant independent.

ISSN:0090-3493    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

ObjectiveTo determine whether direct retrograde ice saline infusion in the jugular vein without cardiopulmonary bypass protects rat brains after heatstroke.DesignRandomized, controlled, prospective study.SettingUniversity physiology research laboratory.SubjectsSprague-Dawley rats (270–320 g, males).InterventionsRats were randomized into three groups and given a) no resuscitation after onset of heat stroke (HS, n = 8); b) ice saline infusion in the femoral vein after onset of heat stroke (HS + F, n = 8); or c) retrograde ice saline infusion in the external jugular vein after onset of heat stroke (HS + J, n = 8). Rats were exposed to an ambient temperature of 43°C after vessel cannulation. Their mean arterial pressure, heart rate, colonic temperature, and brain temperature were continuously recorded. Survival time and brain pathology were checked.Measurements and Main ResultsAlthough colonic temperature decreased 0.8–1.0°C 15 mins after heatstroke in all groups, no treatment-related changes in colonic temperature were noted in any group. However, significant changes were observed in brain temperature. Fifteen minutes after heatstroke, brain temperature was 37.6 ± 0.4°C, 36.1 ± 0.4°C, and 33.6 ± 0.8°C in HS, HS + F, and HS + J, respectively. Survival time was 16.1 ± 2.1, 33.0 ± 3.8, and >120 mins in these groups, respectively. Neuron damage score was significantly lower in HS + J and without lateralization.ConclusionsWe successfully demonstrated that direct retrograde hypothermic perfusion via the jugular vein without cardiopulmonary bypass protected the brain after heat stroke. This technique cooled the brain but did not significantly interfere with body temperature.

ISSN:0090-3493    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

ObjectiveWe examined the effects of arginine vasopressin, when substituted for norepinephrine as a vasopressor in septic shock, on global and hepatosplanchnic hemodynamic and oxygen transport variables.DesignExperimental study.SettingIntensive care unit.SubjectsTwelve septic shock patients.InterventionsNorepinephrine was replaced by vasopressin in a dose sufficient to keep mean arterial blood pressure constant. Blood flow, oxygen delivery, and oxygen consumption of the hepatosplanchnic region (calculated by a hepatic venous catheter technique using the Fick principle during continuous infusion of indocyanine green), global hemodynamics (by thermodilution), and gastric regional Pco2gap (by air tonometry) were calculated during infusion of norepinephrine (mean, 0.56 &mgr;g·kg−1·min−1; range, 0.18–1.1 &mgr;g·kg−1·min−1) and again 2 hrs after replacement by vasopressin (mean, 0.47 IU/min; range, 0.06–1.8 IU/min).Measurements and Main ResultsCardiac index decreased significantly from 3.8 ± 1.3 to 3.0 ± 1.1 L·min−1·m−2, heart rate decreased from 96 ± 14 to 80 ± 16 min−1(p< .01), and global oxygen uptake decreased from 248 ± 67 to 218 ± 75 mL/min (p< .05). Absolute splanchnic blood flow tended to increase, although not significantly, whereas fractional splanchnic blood flow increased from 10.8 ± 7.6 to 25.9 ± 16.6% of cardiac output (p< .05). Gastric regional Pco2gap increased from 17.5 ± 26.6 to 36.5 ± 26.6 mm Hg (p< .01).ConclusionVasopressin, in doses sufficient to replace the vasopressor norepinephrine, had mixed effects in septic shock patients. Hepatosplanchnic blood flow was preserved during substantial reduction in cardiac output. An increased gastric Pco2gap suggests that the gut blood flow could have been redistributed to the disadvantage of the mucosa. Based on these limited data, it does not appear beneficial to directly replace norepinephrine with vasopressin in septic shock.

ISSN:0090-3493    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

ObjectiveTo evaluate long-term survival and functional outcome in intensive care unit survivors after mechanical ventilation for intracerebral hemorrhage.DesignRetrospective chart review and prospective follow-up study.SettingOutpatient follow-up.PatientsBetween 1997 and 2000, 120 patients were mechanically ventilated for an intracerebral hemorrhage at our intensive care unit. Sixty-two patients were discharged from hospital (in-hospital mortality = 48%). Sixty patients were evaluated for survival and functional outcome (two were lost to follow-up). Time between discharge and follow-up was ≥1 yr and was a mean of 27 ± 14 months (range, 12–56).InterventionsNone.Measurements and Main ResultsPatients’ physicians were first asked about survival, and patients or proxies were interviewed by phone. Barthel Index and modified Rankin Scale scores were collected, and demographic information and general data were reviewed. The estimated life-table survival curve after discharge was 64.6% at 1 yr and 57% at 3 yrs. In the 24 patients who died, the mean time between discharge and death was 5 ± 6 months. Probability of death after discharge significantly increased if age at admission was >65 yrs (p< .01; odds ratio, 3.5; 95% confidence interval, 1.4–9.1) and if Glasgow Coma Scale score at discharge was <15 (p< .01; odds ratio, 3.9; 95% confidence interval, 1.6–9.5). In the 36 long-term survivors, Barthel Index was 67.5 ± 15 (median ± median absolute dispersion) and modified Rankin Scale score was 2.6 ± 0.5. Fifteen patients (42%) had a slight or no disability (Barthel Index ≥90 and modified Rankin Scale score ≤2), whereas 21 patients (58%) had moderate or severe disability (Barthel Index ≤85 and modified Rankin Scale score >2).ConclusionsProbability of survival at 3 yrs after mechanical ventilation for an intracerebral hemorrhage was >50%. Age was an important determinant of long-term survival. Forty-two percent of long-term survivors were independent for activities of daily living. Only a few long-term survivors had a very high degree of disability.

ISSN:0090-3493    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

ObjectiveTo determine a contemporary failed extubation rate, risk factors, and consequences of extubation failure in pediatric intensive care units (PICUs). Three hypotheses were investigated: a) Extubation failure is in part disease specific; b) preexisting respiratory conditions predispose to extubation failure; and c) admission acuity scoring does not affect extubation failure.DesignTwelve-month prospective, observational, clinical study.SettingSixteen diverse PICUs in the United States.PatientsPatients were 2,794 patients from the newborn period to 18 yrs of age experiencing a planned extubation trial.InterventionsNone.Measurements and Main ResultsA descriptive statistical analysis was performed, and outcome differences of the failed extubation population were determined. The extubation failure rate was 6.2% (174 of 2,794; 95% confidence interval, 5.3–7.1). Patient features associated with extubation failure (p< .05) included age ≤24 months; dysgenetic condition; syndromic condition; chronic respiratory disorder; chronic neurologic condition; medical or surgical airway condition; chronic noninvasive positive pressure ventilation; the need to replace the endotracheal tube on admission to the PICU; and the use of racemic epinephrine, steroids, helium-oxygen therapy (heliox), or noninvasive positive pressure ventilation within 24 hrs of extubation. Patients failing extubation had longer pre-extubation intubation time (failed, 148.7 hrs, sd ± 207.8 vs. success, 107.9 hrs, sd ± 171.3;p< .001), longer PICU length of stay (17.5 days, sd ± 15.6 vs. 7.6 days, sd ± 11.1;p< .001), and a higher mortality rate than patients not failing extubation (4.0% vs. 0.8%;p< .001). Failure was found to be in part disease specific, and preexisting respiratory conditions were found to predispose to failure whereas admission acuity did not.ConclusionA variety of patient features are associated with an increase in extubation failure rate, and serious outcome consequences characterize the extubation failure population in PICUs.

ISSN:0090-3493    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

ObjectiveTo develop clinical practice guidelines for the use of restraining therapies to maintain physical and psychological safety of adult and pediatric patients in the intensive care unit.ParticipantsA multidisciplinary, multispecialty task force of experts in critical care practice was convened from the membership of the American College of Critical Care Medicine (ACCM), the Society of Critical Care Medicine (SCCM), and the American Association of Critical Care Nurses (AACN).EvidenceThe task force members reviewed the published literature (MEDLINE articles, textbooks, etc.) and provided expert opinion from which consensus was derived. Relevant published articles were reviewed individually for validity using the Cochrane methodology (http://hiru.mcmaster.ca/cochrane/ or www.cochrane.org).Consensus ProcessThe task force met as a group and by teleconference to identify the pertinent literature and derive consensus recommendations. Consideration was given to both the weight of scientific information within the literature and expert opinion. Draft documents were composed by a task force steering committee and debated by the task force members until consensus was reached by nominal group process. The task force draft then was reviewed, assessed, and edited by the Board of Regents of the ACCM. After steering committee approval, the draft document was reviewed and approved by the SCCM Council.ConclusionsThe task force developed nine recommendations with regard to the use of physical restraints and pharmacologic therapies to maintain patient safety in the intensive care unit.

ISSN:0090-3493    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

ObjectivesTo describe three levels of hospital-based critical care centers to optimally match services and personnel with community needs, and to recommend essential intensive care unit services and personnel for each critical care level.ParticipantsA multidisciplinary writing panel of professionals with expertise in the clinical practice of critical care medicine working under the direction of the American College of Critical Care Medicine (ACCM).Data Sources and SynthesisRelevant medical literature was accessed through a systematic Medline search and synthesized by the ACCM writing panel, a multidisciplinary group of critical care experts. Consensus for the final written document was reached through collaboration in meetings and through electronic communication modalities. Literature cited included previously written guidelines from the ACCM, published expert opinion and statements from official organizations, published review articles, and nonrandomized, historical cohort investigations. With this background, the ACCM writing panel described a three-tiered system of intensive care units determined by service-based criteria.ConclusionsGuidelines for optimal intensive care unit services and personnel for hospitals with varying resources will facilitate both local and regional delivery of consistent and excellent care to critically ill patients.

ISSN:0090-3493    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

ObjectiveTo review the epidemiology, clinical features, etiology, diagnosis, and management of severe acute respiratory syndrome (SARS) from a critical care perspective.Data SourcesA MEDLINE search was performed using the following terms: severe acute respiratory syndrome and SARS virus. Additional information and references were obtained from the Web sites for the Centers for Disease Control and Prevention, World Health Organization, and Health Canada.Study SelectionRecent case series were used to develop a review of the epidemiology, clinical features, outcomes, and management of patients with SARS from an intensive care unit (ICU) perspective. This was supplemented by epidemiology information obtained from other Web-based sources. Recent published studies describing the etiology of SARS were also included.Data SynthesisSARS has rapidly spread from Southeast Asia to numerous countries, including Canada and the United States. A new coronavirus has been isolated and detected from many affected patients. The mortality rate worldwide is approximately 10.5%. From five cohorts, the ICU admission rate ranged from 20% to 38%. Fifty-nine percent to 100% of the ICU patients required mechanical ventilatory support. The mortality rate of SARS patients admitted to the ICU ranged from 5% to 67%. The most common clinical symptoms and signs are fever, cough, dyspnea, myalgias, malaise, and inspiratory crackles. Common laboratory abnormalities included mild leukopenia, lymphopenia, and increased aspartate transaminase, alanine transaminase, lactic dehydrogenase, and creatine kinase. The chest radiograph pattern ranged from focal infiltrates to diffuse airspace disease. Management consisted of isolation, strict respiratory and contact precautions, ventilatory support as needed, empiric broad-spectrum antibiotics, ribavirin, and corticosteroids. Predictors of mortality included advanced age, the presence of comorbidities, and a high lactic dehydrogenase or high neutrophil count at admission.ConclusionsSARS is a highly contagious, infectious process that can advance to significant hypoxemic respiratory failure requiring ICU monitoring and support. Early recognition is critical for effective management and containment of this disease.

ISSN:0090-3493    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

ObjectiveTo review barriers to nursing adherence to nonpharmacologic evidence-based guidelines for preventing ventilator-associated pneumonia.DesignDescriptive study.SettingIntensive care units.SubjectsSubjects were 110 nurses approached at two critical care nursing meetings.InterventionsA questionnaire was administered to nurses to assess their adherence to 19 nonpharmacologic prevention strategies and to identify barriers to adherence to evidence-based guidelines.Measurements and Main ResultsFifty-one nurses responded, and overall nonadherence was 22.3%. Significant differences of adherence were identified when compared with the rates previously reported by physicians in nine of the 19 strategies investigated. The most important reasons for nonadherence were unavailability of resources (37.0%), patient discomfort (8.2%), disagreement with reported trial results (7.8%), fear of potential adverse effects (5.8%), and costs (3.4%). Nurses were more likely (p< .05) to identify patient discomfort (odds ratio, 4.8) and fear of adverse events (odds ratio, 3.3), whereas physicians were more likely to report costs (odds ratio, 5.4) and disagreement with interpretation of trials (odds ratio, 3.7) as reasons for nonadherence.ConclusionsNurses had different levels of adherence than physicians for many nonpharmacologic strategies. The most important barriers to implementation were environment-related. Other reasons for nonadherence show significant variability between nurse and physician opinion leaders, patient-related barriers being significantly more important for nurses. Our findings suggest the need for development of multinational guidelines to reduce variability and the need to include the nursing point of view in these guidelines.

ISSN:0090-3493    

出版商:OVID    

年代:2003

数据来源: OVID