Resuscitation
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Laser doppler flowmetry (LDF) is a new non-invasive technique by which microcirculation changes in tissue can be studied. In recent papers, this technique has been used to measure microflow in standardized fluid models, in animals and in human clinical situations. LDF utilizes the doppler shift, i.e. the frequency (wave length) change that light as well as all waves undergo being reflected by moving objects such as, e.g. red blood cells. ⋯ Patient in shock. LDF seems to be an interesting new non-invasive technique, supplying a good definition of the skin microflow. In the future, this technique could be one of the non-invasive techniques used for intensive care, defining the microcirculation state of a patient.
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In spite of good correlations between cardiac output measurements by impedance and established invasive procedures (dye- and thermo-dilution) reported by numerous authors it is doubtful uptil now whether calculations of stroke volume according to the formula of Kubicek et al. (1974) can provide absolutely reliable results. The origin of the dz/dt curve and influencing factors of impedance wave have to be cleared up prior to the total acception of impedance cardiography as a reliable method for determining non-invasive stroke volume. This is true in spite of the agreement of all authors we know, that the reproducibility of the impedance cardiography values is as good as in dye or thermo-dilution measurements. ⋯ The reason for interindividual differences in the thoracic impedance at a given reduction of body water are due to anatomical differences, intrapulmonary air volume and pressure, location of the electrodes, electrical conductivity of the tissue and, above all, due to the position of the body. Therefore if transthoracic impedance is determined sequentially measurements must be performed with special attention to the position of the body to get reproducible results. Rapid infusion of colloids or blood transfusion may decrease transthoracic impedance due to intravascular volume expansion even at a net fluid lost during forced furosemide-induced diuresis or extracorporal hemodialysis.(ABSTRACT TRUNCATED AT 400 WORDS)
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HFPPV is not a jet technique, as it works without air entrainment. A low-compression ventilator, with a conventional rate of 20/min, provides efficient intrapulmonary gas mixing; however, with higher rates of 60-100/min the high inspiratory flow improves transfer/mixing of gas in the conducting airways. ⋯ It is important to note that enhanced gas mixing and improved gas distribution during HFPPV in acute respiratory failure patients are accomplished with lower mean airway pressure, thereby reducing barotrauma. In the future, versatile low-compression ventilators for volume-controlled IPPV and HFPPV will hopefully improve safety, efficiency and patient acceptance of mechanical ventilation in acute respiratory failure.
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Many critically ill patients suffer pain which can produce by itself undesirable effects. Consequently, pain must be carefully prevented, or at least, treated early and effectively. ⋯ Computer-assisted intravenous "on demand" analgesia with Fentanyl can also be used. When pain coverage is required during transient events such as active physiotherapy or dressing changes, additional intravenous of a narcotic (1-2 mg morphine e.g.) or inhalation of nitrous oxide with oxygen are usually effective.
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Increase in total cardiac output can improve oxygen delivery to the cells. Although inotropic drugs increase primarily myocardial contractility, they can adversely affect cardiac preload and afterload. Moreover, they can dangerously increase myocardial oxygen requirements. The combined use of vasodilating agents, with fluid challenge represents a challenging but more efficient treatment of acute circulatory failure.