Journal of clinical monitoring and computing
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J Clin Monit Comput · Jun 2010
Cardiac index measurements by transcutaneous Doppler ultrasound and transthoracic echocardiography in adult and pediatric emergency patients.
Non-invasive hemodynamic monitoring may facilitate resuscitation in critically ill patients. Validation studies examining a transcutaneous Doppler ultrasound technology, USCOM-1A, using pulmonary artery catheter as the reference standard showed varying results. In this study, we compared non-invasive cardiac index (CI) measurements by USCOM-1A with transthoracic echocardiography (TTE). ⋯ The USCOM-1A hemodynamic monitoring technology showed poor correlation and agreement to standard transthoracic echocardiography measures of cardiac function. The utility of USCOM-1A in the management of critically ill patients remains to be determined.
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J Clin Monit Comput · Jun 2010
The standard strong ion difference, standard total titratable base, and their relationship to the Boston compensation rules and the Van Slyke equation for extracellular fluid.
A general formalism for calculating physiological acid-base balance in multiple compartments is extended to the combined interstitial, plasma, and erythrocyte multicompartment system in humans using the Siggaard-Andersen approximation for interstitial fluid. The resulting equations for total titratable base and strong ion difference reproduce the experimental in vivo carbon dioxide titration curve as well as the experimental strong ion difference value of the interstitial, plasma, and erythrocyte system in normal man. The "Boston rules" for compensation in acute respiratory acidosis and alkalosis are then derived analytically from the model. The Van Slyke equation for the interstitial, plasma, and erythrocyte system is also derived and shown to approximate the Van Slyke equation for standard base excess.
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Numerous possibilities exist which may cause obstruction to ventilation under anesthesia resulting in a tight reservoir bag with low compliance. We report an interesting case where a reservoir bag twisted around its own neck and resulted in a tight bag situation. ⋯ We caution all anesthesiologists using the disposable modified Jackson-Rees breathing system to be aware of such an eventuality. We also urge the manufacturer to consider strengthening the neck of the reservoir bag by improving the quality of the material used for its construction.
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J Clin Monit Comput · Apr 2010
Comparative StudyTransthoracic electrical bioimpedence cardiac output: comparison with multigated equillibrium radionuclide cardiography.
Thoracic electrical bioimpedance (TEB) for measuring cardiac output (CO) is being explored increasingly as an alternative to pulmonary artery catheter. The major advantage of this technology is that it is non-invasive and easy to perform. Several studies have compared it to thermodilution cardiac output using PA catheter, with variable correlation. Multigated radionuclide equilibrium cardiography (RNEC) method of cardiac output measurement is known to be reliable. ⋯ This study observed a moderate correlation between TEB and RNEC methods of CO measurement. Further studies are indicated to explore the relative utility of TEB in comparison with RNEC as well as other methods of CO measurement before considering its use in patients with ischemic heart disease.
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J Clin Monit Comput · Apr 2010
Index of consciousness and bispectral index values are interchangeable during normotension and hypotension but not during non pulsatile flow state during cardiac surgical procedures: a prospective study.
Awareness under anesthesia is an avoidable complication during general anesthesia. Anesthetic depth monitors assist anesthesiologists in providing appropriate levels of anesthesia. Index of consciousness monitoring is a recently introduced monitor in the array of anesthesia depth monitors. The objective of this study was to assess the interchangeability of bispectral index, which is already in clinical use and the recently introduced index of consciousness techniques. The other objective was to assess this interchangeability during normotension, hypotension and during pulseless state in patients undergoing coronary artery bypass graft surgery. This study is a prospective observational study, conducted in a tertiary referral hospital. ⋯ The bispectral index and index of consciousness values may be interchangeable. The interchangeability is better appreciated during normotension and hypotension but not during non pulsatile state of cardiopulmonary bypass.