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Biomedical subjects

H J Silverman

Publications and source records attributed to H J Silverman.

At least 19 recordsLinked to original sources
PubMed2001

Implementation of a low tidal volume ventilation protocol for patients with acute lung injury or acute respiratory distress syndrome.

The ARDS (acute respiratory distress syndrome) Network study found 22% lower mortality in acute lung injury and ARDS patients ventilated with low tidal volumes (V(T)) than in those ventilated with traditional V(T) ventilation. Several points should be considered when using the low V(T) protocol for clinical practice. Prior to implementation, hemodynamic and acid-base status, minute ventilation, and adequacy of sedation should be assessed to minimize the potential for intolerance. The volume-preset, assist-control mode is recommended for better control of V(T), and the respiratory rate should be increased as V(T) is reduced, so as to maintain minute ventilation and prevent acute hypercapnia. When unavoidable, hypercapnia should be induced slowly. Ventilator inspiratory flow (V(I)) and trigger sensitivity settings should be optimized to limit the increase in work of breathing and dyspnea. When dyspnea results in double-triggered breaths, V(T) can be titrated to 7-8 mL/kg, provided end-inspiratory plateau pressure is < or = 30 cm H(2)O. In severe acidosis (pH < 7.15) V(T) also can be increased. However, every effort should be made to maintain plateau pressure and V(T) goals by buffering severe acidosis and treating patient-ventilator asynchrony with sedation. Evaluation for weaning should occur when adequate oxygenation can be maintained on 40% oxygen and a positive end-expiratory pressure of 8 cm H(2)O. Pressure support levels between 5 and 20 cm H(2)O (above 5 cm H(2)O positive end-expiratory pressure) are used for weaning and titrated to keep the respiratory rate < 35 breaths/min. Pressure support levels should be weaned aggressively, as long as the protocol's weaning tolerance criteria can be maintained.

Acute Disease↗
PubMed1999

Description of an ethics curriculum for a medicine residency program.

This paper examines the attempts to develop and implement an ethics curriculum for the Internal Medicine Residency Program at the University of Maryland Medical Center. The objectives of the curriculum were to enhance moral reasoning skills and to promote humanistic attitudes and behavior among the residents. The diverse methodologies used to achieve these objectives included case discussions, literature reading, role playing, writing, and videos. These activities occurred predominantly within the forum of morning report sessions and ethics ward rounds. The author also describes efforts to overcome the initial constraints associated with the implementation of this curriculum and concludes by exploring future directions for the curriculum.

Bioethical Issues↗
PubMed1997

Outpatient chest tube management.

BACKGROUND: Patients with indwelling chest tubes inserted for the purpose of evacuating pleural air traditionally are treated in the hospital. The current emphasis on cost-effective medical care and a recent report describing the early discharge of patients who had undergone lung volume reduction operations and had a persistent air leak prompted us to review our overall experience with outpatient tubes in a general thoracic surgical practice. METHODS: We reviewed the records of patients who had been discharged from the hospital with chest tubes and Heimlich valves in place for venting pleural air over the past 7 years. Ambulatory tube management was used on a total of 240 occasions in three diagnostic groups: pneumothorax (176 cases), prolonged postresection air leak (45 cases), and outpatient thoracoscopic pulmonary wedge excision (19 cases). Failure was defined as hospital admission for complications of tube insertion or function. RESULTS: There were 10 failures in the entire group (4.2%), 4.5% for pneumothorax, 2% for postresection air leak, and 5.3% for outpatient thoracoscopy. There were no deaths or instances of life-threatening problems. The cost of at least 1,263 inpatient hospital days was saved. CONCLUSIONS: The presence of a chest tube, with or without an air leak, does not always require hospitalization. Admission can be avoided in most patients with primary spontaneous pneumothorax and in selected patients with pneumothorax of other causes. The postoperative hospital stay can be shortened for many patients who have a prolonged air leak after pulmonary resection. Ambulatory tube management also makes feasible outpatient thoracoscopy for noneffusive processes.

Adolescent↗
PubMed1996

Ethical considerations of ensuring an informed and autonomous consent in research involving critically ill patients.

Despite several codes of research ethics, the issuance of comprehensive rules regarding informed consent by governmental agencies, and numerous writings on the subject of informed consent, many commentators still question the quality of the informed consent process in clinical research. A major concern is that investigators emphasize only the information-giving aspect of "informed" consent, whereas moral philosophy stresses a more robust concept of informed consent that incorporates the additional requirements of subject competence and voluntariness of the consent, thus ensuring that a consent is not only informed, but autonomous as well. This article aims to examine the issues involved with disclosure, competence, and voluntariness, especially those related to research involving critically ill patients. Suggestions concerning methods that can promote an informed consent process that is more respectful of autonomous decision making will also be discussed.

Critical Illness↗
PubMed1995

Implementation of the patient self-determination act in a hospital setting. An initial evaluation.

BACKGROUND: The Patient Self-Determination Act aims to enhance patient awareness of advance directives by requiring health-care institutions to ask patients whether they have advance directives and to inform patients of their rights to prepare these documents. We investigated the following: (1) compliance of the hospital staff with implementing this act, (2) the effects of this act on the extent to which patients discuss and prepare advance directives, and (3) variables that might influence patient discussions on advance planning and preparation of advance directives. METHODS: We surveyed 219 patients from a university hospital that implemented a nurse-dependent advance directive program. We also conducted a telephone interview with 57% of these patients at least 6 months after hospital discharge. RESULTS: Nurses asked 70% of the patients about the existence of an advance directive and of these patients, only 57% remembered the inquiry. Only 57% of the patients received the brochure on advance directives and of these patients, only 55% read the brochure. Only 2% of the patients requested to receive additional information on advance directives. Less than one quarter of the patients had discussions on advance planning while in the hospital and of those patients who were contacted within 6 months after hospital discharge, 39% had discussions on advance planning and 15% prepared an advance directive. Race was an independent predictor for hospital discussions, and educational level was an independent predictor for discussions and preparation of advance directives after hospital discharge. CONCLUSIONS: To enhance the effectiveness of a nurse-dependent advance directive program, hospitals may need (1) to strengthen the quality of the patient-nurse encounter in which the issue of advance directives is raised to more effectively promote patient interest, discussions, and preparation of advance directives and (2) to account for the social diversity of their patient population.

Adult↗
PubMed1995

Discussions with outpatients with chronic obstructive pulmonary disease regarding mechanical ventilation as life-sustaining therapy.

Patients with acute exacerbations of chronic obstructive pulmonary disease (COPD) are often too sick to make informed decisions regarding the use of mechanical ventilation (MV). Prior knowledge of their wishes regarding this form of therapy, therefore, is essential in order to preserve their autonomy. In order to characterize this group of patients with respect to their knowledge of mechanical ventilation as a potential treatment for their disease, we surveyed 40 stable outpatients with the diagnosis of COPD. All patients attended either the general medical clinic or the pulmonary clinic of a university and veterans' hospital. The median age of the patients was 67 years, and the median forced expiratory volume in 1 second was 1.26 L. Consecutive patients were asked to participate in a survey that examined the following questions: (1) Was there an awareness of MV as a treatment modality? (2) Had there been prior discussions with their physicians concerning MV? (3) Were the patients able to express a decision concerning MV as indefinite life-sustaining therapy? Our results showed that 35% of patients were not aware of MV. Only 14% had previously discussed MV with their physicians; 40% indicated a decision to use MV, 22% would decline MV, and 38% were unsure. Patients who had discussions were more likely to specify a choice concerning MV when compared with those patients who had no prior discussions. We conclude that discussions between patients with COPD and their physicians occur infrequently, but when they do occur, they help patients formulate a decision.

Acute Disease↗
PubMed1993

Impaired beta-adrenergic receptor stimulation of cyclic adenosine monophosphate in human septic shock: association with myocardial hyporesponsiveness to catecholamines.

OBJECTIVES: To determine whether myocardial hyporesponsiveness to administered catecholamines occurs in human sepsis and whether this phenomenon is associated with impaired beta-adrenergic receptor stimulation of cyclic adenosine monophosphate. DESIGN: Prospective study. SETTING: Medical ICU in a university hospital. PATIENTS: Normal human volunteers (n = 7), critically ill patients who were not septic (n = 9), septic patients not in shock (n = 16), and septic patients in shock (n = 17). MEASUREMENTS AND MAIN RESULTS: Pulmonary artery catheter-derived hemodynamic data were obtained in patients with sepsis and septic shock. Isoproterenol and sodium fluoride-stimulated cyclic adenosine monophosphate accumulations were measured in circulating lymphocytes. The hemodynamic response to sequential infusions of dobutamine, 5 and 10 micrograms/kg/min, was obtained in septic and septic shock patients. Baseline hemodynamic values for mean arterial pressure, cardiac index, left ventricular stroke work index, and oxygen delivery index at approximately 2 days after the onset of sepsis were significantly lower in septic shock patients compared with septic (nonshock) patients (p < .01 p < .05, p < .001, p < .01, respectively). Isoproterenol- and sodium fluoride-stimulated cyclic adenosine monophosphate accumulations were significantly reduced in septic shock patients compared with those accumulations observed in septic patients (p < .01 and p < .001, respectively). The heart rate response to 10 micrograms/kg/min of dobutamine was significantly (p < .01) lower in septic shock patients compared with septic patients. CONCLUSIONS: In patients with septic shock, impaired beta-adrenergic receptor stimulation of cyclic adenosine monophosphate is associated with myocardial hyporesponsiveness to catecholamines, suggesting that beta-adrenergic receptor dysfunction may contribute to the reduced myocardial performance observed in this shock state.

Adult↗
PubMed1992

Gram-negative sepsis and the adult respiratory distress syndrome.

Gram-negative sepsis has dramatically increased in frequency throughout the twentieth century in the United States. Currently, approximately 200,000 patients develop gram-negative sepsis each year in this country. Of these, about one-quarter develop the adult respiratory distress syndrome (ARDS). Among these critically ill patients, mortality is estimated at 60%-90%. In the complex series of events leading to acute lung injury in gram-negative sepsis, endotoxin is the proximal mediator. Although endotoxin may be capable of causing direct injury to the pulmonary endothelium, its primary role is as a trigger activating inflammatory agents, including complement, neutrophils, and platelets, and inducing the production of cytokines and arachidonic acid metabolites. The end results are impairment of the endothelial barrier, diffusely increased capillary permeability, and adherence of neutrophils to the endothelium with subsequent migration into the tissues. The consequent clinical syndrome is one of acute respiratory distress with pulmonary edema, poorly compliant lungs, and refractory hypoxemia. Endothelial injury often becomes widespread, leading to the failure of multiple organs, including the kidneys, brain, intestine, and liver. Conventional therapy consists of supplemental oxygen, positive end-expiratory pressure, inotropic agents, fluid management, and antibiotics aimed at the offending pathogen. Recent discoveries regarding the mediators of sepsis as well as the expansion of the biotechnological armamentarium have provided clinicians with a plethora of new tools with which to manipulate the host's inflammatory response. The challenge for the next decade will be to ensure the safety, efficacy, and cost-effective use of these expensive but potentially lifesaving immunomodulators, singly or in combination, as adjuvant therapy.

Endotoxins↗
PubMed1992

Gastric tonometry in patients with sepsis. Effects of dobutamine infusions and packed red blood cell transfusions.

We wanted to determine the efficacy of dobutamine infusions and Prbc transfusions on splanchnic tissue oxygen utilization by measuring gastric pHi. Physiologic parameters and pHi measurements via the use of a gastric tonometer were obtained in 21 septic patients before and after the administration of a dobutamine infusion (5 micrograms/kg/min) or the transfusion of two units of Prbc. Subsets of measurements with normal (greater than 7.32) and with low (less than 7.32) pHi were separately analyzed for each intervention. In the dobutamine low pHi group, pHi increased significantly from 7.16 +/- 0.03 to 7.24 +/- 0.03 (n = 9, p less than 0.05). In contrast, pHi failed to increase in the Prbc low pHi subgroup (7.16 +/- 0.05 to 7.17 +/- 0.04 [n = 10, p greater than 0.80]). We conclude that dobutamine rather than Prbc transfusions should be administered to reverse gastric intramucosal acidosis.

Adult↗
PubMed1992

Scalp as a donor site for grafts to facial and neck burns in children.

In facial and neck burns, attention to cosmetic details, in addition to preservation of function, is crucial. The authors describe use of the scalp as a graft donor site for such burns. The advantages include excellent colour match of the graft and minimal morbidity at the donor site. The technique for graft harvest is outlined, and the potential pitfalls are described. Based on their experience with this technique, the authors believe the scalp should be considered as a donor graft site during the acute phase of facial and neck burns.

Burns↗
PubMed1992

Advance directives: implications for critical care.

OBJECTIVE: To discuss the relative merits and limitations of living wills and the durable power of attorney for health care. DATA SOURCES: Computerized search of MEDLINE. STUDY SELECTION: Studies involving treatment decisions at the end of life and descriptive articles on advance directives. RESULTS: The recent Cruzan case and passage of the Patient Self-Determination Act have led to an ethical and legal recognition of advance directives, and therefore, critical care practitioners must be familiar with these documents. A living will is a mechanism by which patients can communicate their desires for medical treatment at the end of life. However, the condition that patients be in a "terminal condition," the inability to predict every possible clinical circumstance, and linguistic vagueness have limited the usefulness of living wills. The durable power of attorney for health care overcomes the inherent restrictive weaknesses of living wills, because informed decisions are made by people based on their knowledge of the patient's beliefs and the nuance of the clinical scenario. A concern with this advance directive is that some patients may not know a suitable person to appoint or that the chosen agent may not be available. CONCLUSIONS: We recommend the execution of both a living will and a durable power of attorney for health care to provide the best assurance that patients' desires concerning medical treatments will be respected.

Advance Directives↗
PubMed1991

Lack of a relationship between induced changes in oxygen consumption and changes in lactate levels.

To determine whether the levels of oxygen consumption (VO2) required to relieve an existing oxygen debt are variable, increases in VO2 produced by increases in oxygen delivery (DO2) were evaluated longitudinally in septic patients with lactic acidosis and related to changes in lactate levels. Interventions were performed in 17 patients and consisted of fluid administration (n = 11), packed red blood cell transfusion (n = 19), or dobutamine infusion (n = 14). Interventions associated with a decreased lactate level or an unchanged/increased lactate level demonstrated similar increases from baseline VO2 (49 +/- 9 and 47 +/- 6 ml/min.m2, respectively) and similar postintervention absolute VO2 values (187 +/- 13 and 189 +/- 10 ml/min.m2, respectively) (both p greater than 0.6). When all interventions were considered, correlations were not observed between changes in lactate levels and changes in VO2 (r = 0.21, p greater than 0.60) or between changes in lactate levels and the postintervention VO2 values (r = 0.08, p greater than 0.45). These observations demonstrate that optimal levels of VO2 are variable and suggest that therapeutic interventions should be tailored to a patient's individual tissue needs and guided by an assessment of an oxygen debt (eg, lactate levels) rather than absolute VO2 measurements.

Acidosis, Lactic↗
PubMed1990

Effects of prostaglandin E1 on oxygen delivery and consumption in patients with the adult respiratory distress syndrome. Results from the prostaglandin E1 multicenter trial. The Prostaglandin E1 Study Group.

We wanted to determine the long-term effects of a continuous infusion of PGE1 on DO2 and VO2 in patients with ARDS. Data were obtained from a randomized double-blind multicenter trial, which evaluated the effects of PGE1 on survival in patients with ARDS. Patients were stratified according to treatment and outcome: placebo-died (n = 8); PGE1-died (n = 12); placebo-survived (n = 9); and PGE1-survived (n = 8). In the placebo-died group, elevations occurred in VO2, which were associated with increases in O2ext and a constant DO2. In contrast, in the PGE1-died group, elevations in VO2 were associated with increases in DO2 and an unchanged O2ext. In the placebo-survived group, VO2 and DO2 decreased, whereas in the PGE1-survived group, VO2 and DO2 increased; however, O2ext decreased in both of these groups. Since impaired O2ext occurs in ARDS, PGE1-induced elevations in DO2, rather than compensatory increases in O2ext, may achieve better tissue oxygenation. We conclude that although the recently completed multicenter trial failed to show an enhancing effect of PGE1 on survival in patients with advanced ARDS, PGE1 may have important effects on oxygen transport and, therefore, may still have a role in the treatment of early manifestations of ARDS, either alone or in combination with other agents.

Alprostadil↗