Critical care medicine
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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.
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Critical care medicine · Mar 1988
Comparative StudyComputer-controlled positive end-expiratory pressure titration for effective oxygenation without frequent blood gases.
We have previously designed a computerized system to automatically deliver PEEP to maintain functional residual capacity (FRC) at a desired value. The purpose of this study was to compare the computerized PEEP titration system with a standard clinical PEEP titration algorithm in the animal adult respiratory distress syndrome (ARDS) model. Thirty mongrel dogs were anesthetized, paralyzed, intubated, and ventilated. ⋯ PaCO2 was maintained at 35.8 +/- 3.4 (SD) torr. There was a significant difference in PEEP delivered between the three groups (p = .0006) and in FRC (p = .005). There was no significant difference in PaO2 (p = .80) or venous admixture (Qva/Qt) (p = .84) between the three groups.(ABSTRACT TRUNCATED AT 250 WORDS)
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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
Delayed respiratory depression following fentanyl anesthesia for cardiac surgery.
High-dose fentanyl anesthesia is widely used in cardiac surgery. Its immediate side-effects are well known. However, its late adverse effect manifested by extreme truncal rigidity, decreased chest wall compliance, hypoventilation, respiratory acidosis and hemodynamic instability is not sufficiently appreciated. ⋯ Administration of naloxone or a muscle relaxant rapidly reversed this late complication of fentanyl, thought to be due to re-entry of fentanyl into plasma from deposits in adipose tissue, muscle and the GI tract, leading to a secondary peak in plasma fentanyl. It is more likely to be encountered when hypothermia, rewarming, and acidosis occur in the postoperative period. Awareness of this life-threatening complication is critical in patients undergoing surgery with fentanyl anesthesia.