Critical care medicine
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Critical care medicine · Apr 1988
Randomized Controlled Trial Comparative Study Clinical Trial Retracted PublicationInfluence of acute normovolemic hemodilution on extravascular lung water in cardiac surgery.
Preoperative hemodilution (HD) is an established blood-saving method. With HD, however, a concomitant increase in extracellular and interstitial water has been reported. This randomized study was undertaken to compare the effects of acute normovolemic HD (10 ml/kg; n = 15) using hydroxyethyl starch solution (HES) on extravascular lung water (EVLW) with those of an untreated control group (n = 15) of cardiac surgery patients submitted to extracorporeal circulation (ECC). ⋯ Hemodynamic and laboratory variables indicated the typical changes during HD (cardiac index increases while albumin concentration decreases); circulatory stability was maintained during the entire study. We conclude that preoperative normovolemic HD did not increase lung water content significantly nor compromise pulmonary function even in cardiac surgery patients. Although ECC provides an additional HD (crystalloid priming of the heart-lung bypass machine) and possibly damage of capillary integrity, the two groups did not differ.
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Critical care medicine · Mar 1988
ReviewEffect of cardiopulmonary resuscitation compression rate on end-tidal carbon dioxide concentration and arterial pressure in man.
The optimal rate of chest compression during CPR in man has been debated. Recently, the end-tidal carbon dioxide concentration (PetCO2) has been shown to correlate with cardiac output during CPR in experimental animals. Eighteen prehospital cardiac arrest patients were studied to determine the effect of external chest compression rate on the PetCO2 and BP in man when ventilation rate, ventilation inspiration time, applied compression force, and a 50:50 downstroke:upstroke ratio were held constant using a microprocessor-controlled CPR Thumper. ⋯ Systolic BP fell progressively from 59 +/- 5 mm Hg at 60/min to 46 +/- 4 mm Hg at 140/min. Diastolic BP remained approximately 23 mm Hg at all rates studied. Using a CPR manikin, we found that greater Thumper compression force was necessary to sustain the same sternal displacement and to achieve the same applied sternal pressure when the rate was increased due to a rate-limited fall in the compression duration.
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Critical care medicine · Mar 1988
Endotracheal tube occlusion associated with the use of heat and moisture exchangers in the intensive care unit.
A heat moisture exchanger (HME) with bacterial filtering capabilities was evaluated over an 8-month period in a total of 170 ICU patients. During this time there were 15 endotracheal tube (ETT) occlusions in 15 patients. Over the ensuing 4 months, cascade humidification was used for 81 patients and only one ETT occlusion occurred (p less than .01). ⋯ Most patients with ETT occlusion required minute volumes greater than 10 L and F10(2) greater than 0.4. We conclude that HMEs do not provide sufficient airway humidification for generalized ICU use. Their role outside of the operating room remains to be determined.