Journal of clinical monitoring and computing
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J Clin Monit Comput · Jan 2000
Comparative Study Clinical TrialNon-invasive estimation of cardiac output in critical care patients.
This study was carried out to compare cardiac output measurements determined by thermodilution and by Portapres, a non-invasive system. ⋯ To date, Portapres measurements cannot replace thermodilution cardiac output estimations. Fluctuations of finger arterial perfusion due to hemodynamic instability, hypothermia and catecholamines may be responsible for problems of Portapres use in critically ill patients.
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J Clin Monit Comput · Jan 2000
ReviewEffects of high thoracic epidural anesthesia and local anesthetics on bronchial hyperreactivity.
Bronchial hyperreactivity can cause life threatening bronchospasm after airway irritation. Therefore, endotracheal intubation is avoided in asthmatics when feasible. High thoracic epidural anesthesia can be used to avoid endotracheal intubation and offers less postoperative pulmonary complications when compared to systemic postoperative analgesia. ⋯ The attenuation of bronchial hyperreactivity can be shown as a dose dependent effect of lidocaine and bupivacaine. The intravenous effect of lidocaine is comparable to the effect of a moderate dose of salbutamol and leads to an additive effect when both drugs are used in combination. Overall, high thoracic epidural anesthesia can be used safely in patients with bronchial hyperreactivity and intravenous administration of lidocaine (1.5-2.0 mg x kg(-1)) can be used as a prophylactic treatment prior to airway instrumentation.
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Inhaled nitric oxide is a ubiquitous molecule which is produced endogenously and is also found in air pollution and in cigarette smoke. After describing the chemistry of NO, we review its history from the first description in 1980 to the current clinical indications. ⋯ Possible drug interactions are listed. Inhaled nitric oxide is here to stay, and future studies will provide more information on its therapeutic dose, duration and potential toxicity.
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J Clin Monit Comput · Jan 2000
ReviewNon-invasive imaging of regional lung function using x-ray computed tomography.
The use of imaging technologies has progressed beyond the depiction of anatomic abnormalities to providing non-invasive regional structure and functional information in intact subjects. These data are particularly valuable in studies of the lung, since lung disease is heterogeneous and significant loss of function may occur before it is detectable by traditional whole lung measurements such as oxygenation, compliance, or spirometry. ⋯ In addition, using the radiodense gas xenon (Xe) as a contrast agent, regional ventilation or gas transport may also be obtained. This communication will review recent advances in CT based techniques for the measurement of regional lung function.
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Pulmonary air embolism is a well-known consequence of surgery, trauma, diving, and aviation. This article reviews the physiological effects, means of detection and methods of prevention and treatment of pulmonary air embolism. The primary physiological effects are elevated pulmonary artery pressures, increased ventilation-perfusion inhomogeneity, and right ventricular failure. ⋯ Prevention measures include volume expansion, careful positioning, positive end-expiratory pressure, military anti-shock trousers, and jugular venous compression. Treatment of pulmonary air embolism includes flooding the surgical site with saline, controlling sites of air entry, repositioning the patient with the surgical site below the right atrium, aspiration of air from a central venous catheter, cessation of inhaled nitrous oxide, and resuscitation with oxygen, intravenous fluids, and inotropic agents. Some hypotheses on the effects of air in the pulmonary vasculature and investigational treatment options are discussed.