ISSN:1046-7467    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

For centuries, medical practitioners had no electronic medical instruments and had to rely on their senses of sight, hearing, smell, taste, and touch to obtain physiologic measurements. Although it is possible to estimate blood pressure by palpating the pulse at the radial or brachial artery, such estimates are not accurate. Determining arterial oxygen saturation of hemoglobin is more complex: how “blue” a patient appears depends on skin coloration, lighting, and the examiner's sense of color. Finally, using radiographic images to validate pulmonary edema when clinicians suspect that there is an elevated left atrial or pulmonary artery wedge pressure also challenges human senses. However, today's medical instruments use transducers and signal processors to convert patient information into a form that clinicians can easily perceive and understand. This article defines terms used with biomedical instrumentation and discusses the components of ideal physiologic patient monitoring systems

ISSN:1046-7467    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

A recent national survey of critical care nurses reveals that the leads many nurses select to monitor their patients are diagnostically inferior to other available leads, and that lead placement often is inaccurate. This article reviews the best leads for electrocardiographic (ECG) monitoring, illustrates their accurate placement, and explains reasons for the dilemma in current practice. Questions relevant to practicing nurses are addressed, including 1) Is lead MCL, as good as V,? 2) When is it appropriate to substitute lead MCL, for V,? and 3) How important is it for electrodes to be placed exactly in specific anatomic locations? Finally, a case study is provided to illustrate how accurate monitoring can prevent misdiagnosis and resultant inappropriate therapy.

ISSN:1046-7467    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

Many patients in the critical care unit (CCU) are at risk for myocardial ischemia and acute coronary artery reocclusion. The use of continuous ST segment monitoring detects transient and sustained ischemia, despite the absence of symptoms, more completely than rate and rhythm monitoring alone. The accuracy and sensitivity of the ST segment for detection of ischemia is dependent on the number and location of the electrocardiographic leads used in conjunction with the site of obstruction. Thus, when using ST segment monitoring for detection of ischemia, one of the most important decisions for the nurse to make is lead selection. In addition, both ischemic and nonischemic ST segment changes must be considered

ISSN:1046-7467    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

Vigilant and accurate assessment of thermal balance is imperative with the critically ill. Disease, injury, or pharmacologic activity can impair thermoregulation, leaving patients vulnerable to uncontrolled gain or loss of heat. Body temperature provides cues to onset of infection, inflammation, and antigenic responses, as well as indicating efficacy of treatment. With knowledge of heat transfer principles, physiologic processes that distribute body heat, and principles of thermometry, the nurse is better equipped to make reasoned clinical judgment about this important vital sign. Choices of instruments or measurement sites are influenced by needs to estimate either hypothalamic temperature or shifts in body heat. Need for continuous versus episodic assessment, availability or intrusiveness of equipment, and stability of the patient also influence choices. Monitoring devices, measurement sites and techniques, equipment limitations and precautions are discussed. Interpretation and application of assessment findings are presented as they relate to abnormally high or low temperatures, patterns of fever, and temperature gradients

ISSN:1046-7467    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

The assessment of pulmonary function, from a clinical perspective, can be performed accurately only if the clinician understands the concept ventilation/ perfusion ratios of the lung. The major categories of ventilation/perfusion ratios are intrapulmonary shunting and physiologic deadspace. Virtually all pulmonary assessments and interventions are aimed to address Qs/Qt or Vd/Vt. This chapter provides background information useful to the clinician in the assessment of intrapulmonary shunting and deadspace analysis. From this information, more thorough assessments of pulmonary function are possible

ISSN:1046-7467    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

Arterial blood pressure (BP) measurements, which include invasive direct methods and noninvasive indirect methods, provide a picture of the hemodynamic status of the patient. Invasive BP methods measure pressure pulse wave amplitude; noninvasive methods rely on blood flow or arterial wall motion as a basis for the determination of BP values. To obtain the most accurate BP value, the clinician must identify which measurement variables in a specific clinical situation are most contributory to error and, if possible, use a method of measurement for which the sources of error are not parallel. Blood pressure values obtained by different methods cannot be compared without a thorough understanding of the user-related and instrumentation-related limitations associated with each BP measurement technique

ISSN:1046-7467    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

Critical care nurses frequently are involved in obtaining cardiac output measurements and in using these data to assess and to plan therapy. This article reviews the physiologic determinants of cardiac output and the clinical factors that influence these determinants. Principles and techniques of common methods of cardiac output measurement arc discussed. A thorough presentation of guidelines for troubleshooting problems with thermodilution cardiac output measurement is provided in a table. Nursing management issues are discussed using relevant nursing research. Future considerations in cardiac output measurement are discussed, and suggestions of an ideal cardiac output system are provided

ISSN:1046-7467    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

Critical care nurses often care for critically ill patients who require pulmonary artery catheterization. Nurses need an extensive knowledge base to understand the various technical and physiologic factors that may affect the accuracy of pressure measurements. Continued nursing research is needed to refine and guide the development of nursing practice standards in caring for patients who require pulmonary artery pressure monitoring.

ISSN:1046-7467    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

The goal of invasive hemodynamic monitoring is to evaluate the components of oxygen delivery and consumption. Parameters obtained from the physiologic profile are used to assess and optimize oxygen delivery to meet the tissue needs of the critically ill patient. Oxygen delivery is defined as cardiac output multiplied by the arterial oxygen content. Research has demonstrated that adequate increases in oxygen delivery improve survival. The primary intervention for optimizing oxygen delivery is appropriate fluid resuscitation. Classic endpoints of adequate fluid resuscitation have been pressurebased parameters, which possess many inherent assumptions. Current clinical issues are directed toward assessment of the patient's status in relation to the oxygen supply-and-demand balance. Identification of therapeutic interventions to achieve the goal of increasing oxygen delivery are paramount. Evaluation of the role of the right ventricle (RV) in biventricular performance and incorporation of volumetric measurements to assess the critically ill patient are presented

ISSN:1046-7467    

出版商:OVID    

年代:1993

数据来源: OVID