Articles: critical-illness.
-
Minerva anestesiologica · Jun 1993
Comparative Study[The thermodilution determination of right ventricular volumes and ejection fraction in the critical patient. Volumetric vs pressure measurement assessment].
The widespread use of hemodynamic investigation techniques, allowed a better understanding of the right ventricle (RV) pathophysiology and led to progressive reevaluation of its role. A modification of the classical Swan-Ganz catheter, made possible the measurement of the ejection fraction (EF) and of the end-systolic and end-diastolic volumes of RV just by the simple application of the thermodilution technique. In this paper, we first refreshed the basic theoretical principles of the technique and then presented our preliminary results of one-year experience in ICU. ⋯ We conclude that the use of the thermodilution technique to measure the volumes of RV, allows a real evaluation of the preload. At the same time it avoids all the problems associated with the measurement of transmural pressure and with the changes produced by shifting of intrapleural pressure. Finally the end systolic volume may be combined with the pressure data to estimate the contractile status and, in our experience, this parameter has proved more sensitive than EF in order to detect changes of contractility of the right ventricle.
-
Patients who require mechanical ventilation are often sedated with midazolam. As clinical signs of sedation are often confusing or nonexistent, and there are few adverse side effects when large doses are infused over a period of days, substantial drug accumulation can result in these critically ill patients, despite the short half-life of midazolam. An objective monitor of sedation would help maintain sedation at a constant level despite changing pharmacokinetic values in patients. ⋯ High frequency electroencephalogram activity decreased as sedation level increased. This was reflected in decreases in the spectral edge (17.61 to 10.56 Hz (p = 0.0024)), the median frequency (4.27 to 2.56 Hz (p = 0.0278)), and the logarithm of the absolute power in the beta 1 (p = 0.0012), and beta 2 (p < 0.0001) bands. An incidental finding of asymmetry in power between right and left frontal electrodes was observed, with right-sided power being 9-18% greater (p < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)
-
Surg Gynecol Obstet · May 1993
The failure of conventional methods to promote spontaneous transpyloric feeding tube passage and the safety of intragastric feeding in the critically ill ventilated patient.
Nasoenteral tube feedings are often recommended in critically ill patients when gastrointestinal tract function is intact. Conventional methods of placement include turning the patient on the right side and the use of drugs that stimulate peristalsis to promote transpyloric passage. A prospective study was initially performed to assess the success of conventional methods used to promote transpyloric feeding tube placement in patients requiring assisted ventilation admitted to the Surgical Intensive Care Unit (SICU) (Part I of the study). ⋯ The presence of complications was not related to age, gender, admitting diagnosis, infusion method or type of formula used. Duodenal intubation using conventional methods in critically ill ventilated patients is unsuccessful in most patients. Nasogastric feeding in this group of patients can be safely administered in selected instances.
-
Intensive care patients often require inotropic support to stabilise circulation and to optimise oxygen supply. In this context, the catecholamines norepinephrine (noradrenaline), epinephrine (adrenaline), dopamine and dobutamine are still the mainstay of therapy. They provide, to different extents, a variety of adrenoceptor-mediated actions comprising vasoconstriction (via alpha-receptors) as well as vasodilatation (via beta 1-receptors), and an increase in cardiac output by enhancing inotropy and heart rate (again via beta 1-receptors). ⋯ Depending on the dosage and the speed of intravenous administration, the use of phosphodiesterase inhibitors sometimes results in pronounced decrease of blood pressure which may require vasopressor therapy. Other drugs including histamine H2-agonists are currently under investigation. Their value in the treatment of intensive care patients has still to be evaluated.
-
Positioning of critically ill patients affects hemodynamic and cardiopulmonary outcomes. A review of clinical studies indicates that backrest elevations up to 60 degrees do not affect measurement of intracardiac pressures or cardiac output, but PaO2 may diminish in sitting positions following surgical procedures. In lateral positions, measurement of intracardiac pressures and cardiac output is not recommended, since a uniform reference point has not been identified for lateral positions. ⋯ Prone positioning may be beneficial in adult respiratory distress syndrome and in weaning of mechanically ventilated patients. When planning positioning maneuvers, critical care nurses should consider these effects in relation to the specific needs of each patient. Hemodynamic and cardiopulmonary responses to positioning should be evaluated in conjunction with other therapeutic modalities such as those designed to preserve skin integrity and improve comfort.