Search PubMed⌕ Search

Biomedical subjects

Herbert P Wiedemann

Publications and source records attributed to Herbert P Wiedemann.

15 recordsLinked to original sources
PubMed2006

Pulmonary-artery versus central venous catheter to guide treatment of acute lung injury.

BACKGROUND: The balance between the benefits and the risks of pulmonary-artery catheters (PACs) has not been established. METHODS: We evaluated the relationship of benefits and risks of PACs in 1000 patients with established acute lung injury in a randomized trial comparing hemodynamic management guided by a PAC with hemodynamic management guided by a central venous catheter (CVC) using an explicit management protocol. Mortality during the first 60 days before discharge home was the primary outcome. RESULTS: The groups had similar baseline characteristics. The rates of death during the first 60 days before discharge home were similar in the PAC and CVC groups (27.4 percent and 26.3 percent, respectively; P=0.69; absolute difference, 1.1 percent; 95 percent confidence interval, -4.4 to 6.6 percent), as were the mean (+/-SE) numbers of both ventilator-free days (13.2+/-0.5 and 13.5+/-0.5; P=0.58) and days not spent in the intensive care unit (12.0+/-0.4 and 12.5+/-0.5; P=0.40) to day 28. PAC-guided therapy did not improve these measures for patients in shock at the time of enrollment. There were no significant differences between groups in lung or kidney function, rates of hypotension, ventilator settings, or use of dialysis or vasopressors. Approximately 90 percent of protocol instructions were followed in both groups, with a 1 percent rate of crossover from CVC- to PAC-guided therapy. Fluid balance was similar in the two groups, as was the proportion of instructions given for fluid and diuretics. Dobutamine use was uncommon. The PAC group had approximately twice as many catheter-related complications (predominantly arrhythmias). CONCLUSIONS: PAC-guided therapy did not improve survival or organ function but was associated with more complications than CVC-guided therapy. These results, when considered with those of previous studies, suggest that the PAC should not be routinely used for the management of acute lung injury. (ClinicalTrials.gov number, NCT00281268.).

Analysis of Variance↗
PubMed2006

Comparison of two fluid-management strategies in acute lung injury.

BACKGROUND: Optimal fluid management in patients with acute lung injury is unknown. Diuresis or fluid restriction may improve lung function but could jeopardize extrapulmonary-organ perfusion. METHODS: In a randomized study, we compared a conservative and a liberal strategy of fluid management using explicit protocols applied for seven days in 1000 patients with acute lung injury. The primary end point was death at 60 days. Secondary end points included the number of ventilator-free days and organ-failure-free days and measures of lung physiology. RESULTS: The rate of death at 60 days was 25.5 percent in the conservative-strategy group and 28.4 percent in the liberal-strategy group (P=0.30; 95 percent confidence interval for the difference, -2.6 to 8.4 percent). The mean (+/-SE) cumulative fluid balance during the first seven days was -136+/-491 ml in the conservative-strategy group and 6992+/-502 ml in the liberal-strategy group (P<0.001). As compared with the liberal strategy, the conservative strategy improved the oxygenation index ([mean airway pressure x the ratio of the fraction of inspired oxygen to the partial pressure of arterial oxygen]x100) and the lung injury score and increased the number of ventilator-free days (14.6+/-0.5 vs. 12.1+/-0.5, P<0.001) and days not spent in the intensive care unit (13.4+/-0.4 vs. 11.2+/-0.4, P<0.001) during the first 28 days but did not increase the incidence or prevalence of shock during the study or the use of dialysis during the first 60 days (10 percent vs. 14 percent, P=0.06). CONCLUSIONS: Although there was no significant difference in the primary outcome of 60-day mortality, the conservative strategy of fluid management improved lung function and shortened the duration of mechanical ventilation and intensive care without increasing nonpulmonary-organ failures. These results support the use of a conservative strategy of fluid management in patients with acute lung injury. (ClinicalTrials.gov number, NCT00281268 [ClinicalTrials.gov].).

Blood Pressure↗
PubMed2006

Pulmonary artery catheter and fluid management in acute lung injury and the acute respiratory distress syndrome.

The PAC provides a wealth of information about circulatory and respiratory systems and intravascular fluid volume over time. Specifically, the PAC allows measurement of central venous and pulmonary arterial pressure, pulmonary artery occlusion pressure, mixed venous blood gases, and indicator-dilution cardiac output. Based on these quantitative date, systemic and pulmonary vascular resistance can be derived. The PAC is frequently used in patients with ALI and ARDS, both to confirm the diagnosis and to optimize hemodynamic management. In this article, we review the evidence on the use of the PAC in patients with ALI/ARDS, paying particular attention to the recently published fluid and catheter treatment trial by the ARDS Clinical Trials Network.

Body Fluids↗
PubMed2005

Partial liquid ventilation in adult patients with acute respiratory distress syndrome.

RATIONALE: Despite recent clinical trials demonstrating improved outcome in acute respiratory distress syndrome (ARDS), mortality remains high. Partial liquid ventilation (PLV) using perfluorocarbons has been shown to improve oxygenation and decrease lung injury in various animal models. OBJECTIVE: To determine if PLV would have an impact on outcome in patients with ARDS. METHODS: Patients with ARDS were randomized to (1) conventional mechanical ventilation (CMV; n=107), (2) "low-dose" perfluorocarbon (10 ml/kg; n=99), and (3) "high-dose" perfluorocarbon (20 ml/kg; n=105). Patients in all three groups were ventilated using volume ventilation, Vt or= 0.5, and positive end-expiratory pressure >or= 13 cm H(2)O. RESULTS: The 28-d mortality in the CMV group was 15%, versus 26.3% in the low-dose (p=0.06) and 19.1% in the high-dose (p=0.39) PLV groups. There were more ventilator-free days in the CMV group (13.0+/-9.3) compared with both the low-dose (7.4+/-8.5; p<0.001) and high-dose (9.9+/-9.1; p=0.043) groups. There were more pneumothoraces, hypoxic episodes, and hypotensive episodes in the PLV patients. CONCLUSIONS: PLV at both high and low doses did not improve outcome in ARDS compared with CMV and cannot be recommended for patients with ARDS.

Dose-Response Relationship, Drug↗
PubMed2005

Mortality in individuals with severe deficiency of alpha1-antitrypsin: findings from the National Heart, Lung, and Blood Institute Registry.

STUDY OBJECTIVE: To clarify the mortality rate and causes of death of individuals with alpha(1)-antitrypsin (AAT) deficiency, the Death Review Committee (DRC) of the National Heart, Lung, and Blood Institute Registry of Individuals with Severe AAT Deficiency reviewed all available medical records regarding the deaths of study subjects during Registry follow-up (up to 7.2 years). METHODS: Individual determinations by each member of the three-person DRC led to consensus judgments regarding the underlying cause and the immediate and contributing causes of death. RESULTS: Of the 1,129 Registry subjects, 204 died (18.1%) [approximately 3%/yr]. Record availability permitted detailed review in 120 decedents, and death certificates were available in 56 of the remaining 84 subjects (67%). Emphysema and cirrhosis were the most common underlying causes of death (72% and 10%, respectively), with malignancy and diverticulitis accounting for 3% of deaths each. To assess attributable mortality, standardized mortality ratio analysis was performed and indicated that excess mortality was ascribable entirely to lung and liver disease. CONCLUSIONS: We conclude that severe AAT deficiency poses a significant threat to health, that severe airflow obstruction is a major determinant of mortality, and that liver and lung disease account for the excess mortality in affected individuals. These findings support current efforts to enhance diagnostic recognition and treatment of AAT-deficient individuals.

Adult↗
PubMed2004

The bronchopulmonary pathology of alpha-1 antitrypsin (AAT) deficiency: findings of the Death Review Committee of the national registry for individuals with Severe Deficiency of Alpha-1 Antitrypsin.

To assess the pathological changes in the lungs and liver of 42 individuals who died while enrolled in the Registry of Individuals with Severe Deficiency of Alpha-1 Antitrypsin (AAT), all available histopathologic surgical or postmortem-derived specimens were reviewed by the pathologist member of the Death Review Committee. The underlying cause of death was emphysema in 34 patients and cirrhosis in 2 patients. Slides of lung were graded for emphysema, and liver specimens were graded for fibrosis, using respective pictorial scoring systems. Correlations between the degree of pathological abnormality and clinical features were evaluated. All lungs exhibited severe panacinar emphysema (mean emphysema score, 7.9 +/- 1.06 [standard deviation], where 10 represents the greatest severity) with a lower lobe predominance. Centriacinar emphysema was minimal. No correlation was found between the pathological severity of emphysema and pulmonary function measurements, and no significant correlation was found between the degree of emphysema and the degree of hepatic fibrosis. Mildly increased bronchial gland-to-wall ratio accompanied mild inflammation and goblet cell hyperplasia. There were minimal changes in small airways. Dilatation of membranous bronchioles was a frequent finding; however, bronchiectasis of larger airways was a minor feature in only 6 patients (15%). Airway morphological features did not correlate with the clinical presence of chronic bronchitis or asthma. Although the lack of correlation between liver and lung pathological changes may reflect different pathogenetic mechanisms of liver disease and lung disease, the lack of correlation between emphysema grade and lung function likely reflects the skewed sample in a series of patients with advanced lung disease.

Cause of Death↗
PubMed2003

Emerging systemic pharmacologic approaches in acute respiratory distress syndrome.

The increased understanding of the pathophysiology of ALI that has been achieved over the last decade has led to several new pharmacologic approaches for the prevention and management of ALI and ARDS. Based on in vitro information and animal model data, many of these strategies seem quite compelling. Nevertheless, to date, no specific pharmacologic approach for the prevention or treatment of ARDS has been conclusively validated in clinical trials. Active basic and clinical research continues, and it is hoped that these investigations will lead to new therapies that can be applied by the clinician to improve clinical outcomes for patients who have ALI and ARDS.

Adrenal Cortex Hormones↗
PubMed2003

Cor pulmonale: an overview.

Chronic cor pulmonale involves the enlargement of the right ventricle as a result of pulmonary hypertension due to pulmonary disorders involving the lung parenchyma, bellows function, or ventilatory drive. The right ventricular hypertrophy that occurs in chronic cor pulmonale is a direct result of chronic hypoxic pulmonary vasoconstriction and subsequent pulmonary artery hypertension, leading to increased right ventricular work and stress. We discuss methods by which hypoxic vasoconstriction and reduction in the pulmonary vascular bed lead to the development of pulmonary artery hypertension. This article reviews the interaction of the pulmonary vasculature and right ventricle in the non-diseased state as well as during disease exacerbations. Ventricular dependence and its contribution to the pathophysiology of right ventricular failure are also reviewed. In addition, we provide an overview of specific disease states that can result in the development of chronic cor pulmonale including chronic obstructive pulmonary disease (COPD), interstitial lung disease, sleep apnea, alveolar hypoventilation disorders, and primary pulmonary hypertension. We also review the current diagnostic studies used to evaluate and study cor pulmonale.

Journal Article↗
PubMed2002

Systemic lupus erythematosus in the intensive care unit.

SLE causes significant morbidity and mortality by multisystem organ involvement. Infections are the leading cause of morbidity and mortality in patients with SLE. Meticulous exclusion of infection is mandatory in patients with SLE, because infections may masquerade as exacerbation of underlying disease; and the immunosuppression used to treat severe forms of exacerbation of lupus can have catastrophic consequences in patients with infections. Corticosteroids are the first-line therapy for most noninfectious complications of SLE, with various adjuvant immunosuppressive agents such as cyclophosphamide being increasingly used in combination with plasmapheresis. Some recent series have shown an improved survival rate, but this improvement needs to be confirmed by further studies. Controlled trials comparing various therapeutic options are lacking, and optimal therapy has not been defined.

Cardiovascular Diseases↗
PubMed2002

Incidence of ARDS in an adult population of northeast Ohio.

STUDY OBJECTIVES: To assess the incidence of the ARDS in a well-defined adult population. DESIGN: Kaiser Permanente of northeast Ohio, a health maintenance organization, uses the Cleveland Clinic Foundation as its only tertiary care center. In an ongoing prospective assessment in the Cleveland Clinic ICUs, we identified adult Kaiser Permanente patients with ARDS between 1996 and 1999. ARDS was defined according to the 1994 American-European Consensus Conference criteria. The denominator in the incidence calculation was the adult members of Kaiser Permanente of each year of the study period, and the numerator was the new adult ARDS patients in this particular year. The cause of ARDS, the mortality, and the cause of death were retrospectively identified, as well as other characteristics of the study population. RESULTS: ARDS was diagnosed in 66 patients during the 3-year study period. The incidence per 100,000 population was 11.4 in 1996, 19.8 in 1997, and 14.4 in 1998; the overall incidence was 15.3/100,000/yr. The mean PaO(2)/fraction of inspired oxygen (+/- SD) was 110.8 +/- 37.8, the mean APACHE II was 23.4 +/- 6.9, and the mean ICU stay was 12.0 +/- 9.5 days. The most common cause of ARDS was direct lung injury (75.8%), and the most common cause of death was septic shock (53.8%). CONCLUSION: The incidence of ARDS in an adult population in northeast Ohio was 15.3/100,000/yr, a number that is slightly higher but comparable to recent estimates reported by other researchers.

Female↗