ISSN:1075-2765    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Transesophageal atrial stimulation was applied in 56 patients to terminate atrial flutter. Extrastimulation and atrial burst techniques were applied using programmable stimulator (Medtronic 5328) and hexapolar esophageal electrode catheters. Thirty patients were randomized to receive digoxin pretreatment (group A), and 26 patients were randomized to receive procainamide pretreatment (group B). Efficacy of each pretreatment was evaluated by observing the change in the rhythm. In group A, transesophageal pacemaker therapy successfully converted atrial flutter to sinus rhythm in 13 patients and to atrial fibrillation in 14 patients, whereas the arrhythmia remained unchanged in the 3 remaining patients in the digitalized group. In group B, after procainamide pretreatment, sinus rhythm appeared in 19 and atrial fibrillation in 5, and no change was observed in the remaining 2 patients. Procainamide is more efficacious than digoxin (P< 0.05) in facilitating cardioversion by transesophageal stimulation.

ISSN:1075-2765    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Endogenous carbon monoxide (CO) is produced in the degradation of heme by heme oxygenase. Studies have shown that hypoxia induces heme oxygenase production of CO in vascular tissue. Because elevated plasma lactate levels are associated with tissue hypoxia, we determined if there was any correlation between lactate and carboxyhemoglobin (COHb) levels in a group of critically ill patients with a high likelihood of hypoxia. In a 7.5-month period, 5322 simultaneous arterial COHb and lactate measurements were performed routinely on 183 patients with a blood gas analyzer in the Department of Veterans Affairs Medical Center, Bronx, New York, Surgical Intensive Care Unit. Sixty-one percent of the patients had elevated lactate levels (>2.5mmol/L), and 46% had elevated COHb levels (>1.5%). Lactate levels ranged from 0.12 to 22.7 mmol/L and COHb levels from 0% to 4.8%. There was no correlation between lactate and COHb levels (r= .07 withP< .0001). Levels of endogenous CO do not increase in situations in which lactate production is increased. It is possible that changes in endogenous production of CO may not significantly affect the circulating level of COHb. Although readily available, COHb levels do not seem to be clinically useful as markers of critical illness.

ISSN:1075-2765    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

The engineering risk analysis method can be extended to include some human and organizational factors and can be used in the medical domain; this transfer is illustrated by a description of a study of anesthesia patient risk. This study involves first a dynamic analysis of accident risks. The model is then extended by relating the basic events of accident scenarios to the state of the practitioner described by the probability of personal problems that may affect his or her level of competence and alertness. These potential problems, in turn, are linked (by probabilistic relations) to the way the system is managed. This extension of the analytical framework allows assessment of the effect of particular types of practitioner problems and therefore of corresponding risk mitigation measures on the probability of the different accident scenarios. The risk analysis model can then be used as a management tool that permits setting priorities among patient safety measures, based either on the sole benefits of the corresponding decrease of patient risk or on a cost-to-benefit ratio. This probabilistic approach constitutes a departure from the classic risk studies exclusively based on statistical frequencies because it involves both available statistics and expert opinions. It is commonly used in engineering for systems for which there is not enough information at the time when decisions need to be made. I show here how the probabilistic model can be used in the medical field to support patient safety decisions before complete data sets can be gathered or in cases in which some key factors are not directly observable.

ISSN:1075-2765    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Patients with chronic heart failure (CHF) have an increased risk for sudden death. This increased risk has been associated with increased QT dispersion (QTd), a reflection of the heterogeneity in ventricular repolarization. Angiotensin-converting enzyme (ACE) inhibitors have been reported to decrease heart size as well as decreasing morbidity and mortality in moderate-to-severe CHF. The aim of this study was to determine if ACE therapy is associated with a decrease in QTd, a marker for increased electrical instability. Ninety-seven patients were evaluated. The normalized QTd after 2 months of ACE therapy decreased from 16 ± 4 to 12 ± 3, a 25% reduction in dispersions. QTd also decreased from 61 ± 14 to 47 ± 12 (P< .001) and QTc dispersions decreased from 71 ± 18 to 52 ± 14 (P< .001). After 2 months of ACE inhibitor therapy, heart rate slowed significantly (RR intervals 765 ± 198 before and 838 ± 186 after ACE). There was a negative correlation between ejection fraction and QTd (r= −0.8;P< .001). The study also found no correlation between ACE level, percent converting enzyme inhibition, and QTd. The effects of ACE therapy appear early on in terms of repolarization changes. The reduction in QTd may explain the reduced sudden death mortality in patients with heart failure who are treated with ACE inhibitor therapy.

ISSN:1075-2765    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

One of the many provisions of the recently enacted Food and Drug Administration Modernization Act (FDAMA) provides for an additional period of market exclusivity in exchange for completed pediatric studies requested by the FDA for certain drugs of potential benefit to the pediatric population. The impetus for this law centers around two facts: Drugs needed in the pediatric population lack labeling for pediatric use, and industry lacks incentive to perform studies to support this additional labeling. Congress has now provided the incentive. The success of the pediatric initiative will rest initially on industry's willingness and readiness to do the studies. This willingness, in turn, will depend on FDAMA's impact on the economics of drug development and the availability of pediatric research capacity, both of which could be affected by the FDA's final rule on the assessment of safety and effectiveness of drugs and biologicals for pediatric patients. This rule will compel firms to conduct pediatric studies similar to the ones encouraged under FDAMA's voluntary pediatric exclusivity program. Although the Act provides for the statutory harmonization of the rule with the Act, whether the effects of the rule on the Act have been fully contemplated is a premise considered in this article. Congress too has much to contemplate as they evaluate the FDA's report, due in less than 2 years, on the public health effectiveness and economic effects of the Act's incentive program in preparation for possible FDAMA II modifications.

ISSN:1075-2765    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Fenoldopam is a direct-acting vasodilator that acts at the postsynaptic dopamine 1 receptors in renal, coronary, cerebral, and splanchnic vasculature resulting in arterial dilation and a lowering of the mean arterial pressure (MAP). Preliminary evidence suggests its efficacy in the treatment of hypertensive urgencies and emergencies in adults. We present four children in whom fenoldopam was used to control MAP in various clinical scenarios, including hypertensive emergencies and urgencies, intraoperative reduction of MAP for controlled hypotension, and control of MAP during extracorporeal membrane oxygenation. The possible applications of fenoldopam and suggested dosing regimens in children are reviewed.

ISSN:1075-2765    

出版商:OVID    

年代:1999

数据来源: OVID

ISSN:1075-2765    

出版商:OVID    

年代:1999

数据来源: OVID