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Cost containment, as an essential part of current effort to manage health care, has been examined thoroughly from the perspectives of finance and patient care. In this article, the ethics of cost containment are discussed from the vantage point of the health care provider. Cost-cutting initiatives, however necessary and sound, nevertheless may place anesthesiologists in situations of ethical conflict and ultimately interfere with their rights as workers and professionals. The anesthesiology community is encouraged to investigate the effect of cost-cutting measures on patients and physicians alike.

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UNLABELLED: Although continuous auscultation has been used during surgery as a monitor of cardiac function for many years, the effect of anesthetics on heart sounds has never been quantified. We determined the root mean squared amplitude and frequency characteristics (peak frequency, spectral edge, and power ratios) of the first (S1) and second (S2) heart sounds in 19 healthy children during induction of anesthesia with halothane. In all patients, halothane decreased the amplitude of S1 (R2 = 0.87 +/- 0.12) and S2 (R2 = 0.66 +/- 0.33) and the high-frequency components (>80 Hz) of these sounds. These changes were clearly audible and preceded decreases in heart rate and blood pressure. The spectral edge decreased for S1 in 18 patients (R2 = 0.73 +/- 0.24) and for S2 in 13 patients (R2 = 0.58 +/- 0.25). Peak frequency did not change. The rapidity with which myocardial depression and its associated changes in heart sound characteristics occurred confirms that continuous auscultation of heart sounds is a useful clinical tool for hemodynamic monitoring of anesthetized infants and children. IMPLICATIONS: Heart sound characteristics can be used to monitor cardiac function during halothane anesthesia in children. The changes occur rapidly and precede noticeable changes in heart rate and blood pressure.

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UNLABELLED: Although the esophageal stethoscope has been used for many years, the effect of the depth of placement on the quality of the sounds obtained has never been investigated. The amplitude and frequency characteristics of the first and second heart sound and of inspiratory and expiratory breath sounds were determined at various stethoscope depths (from the distal tip) in 17 healthy anesthetized adults. The amplitude for each type of sound varied markedly with depth. Maximal amplitude for S1 was at 34 +/- 3 cm, for S2 at 27 +/- 2 cm, for inspiratory breath sound at 28 +/- 2 cm, and for expiratory breath sound at 26 +/- 2 cm. There was a positive linear correlation between the depth of maximal amplitude of these sounds and patient height. Peak frequency, in general, did not change with depth. We conclude that investigators should measure and document depth when performing studies involving the esophageal stethoscope. IMPLICATIONS: Analysis of sound from the esophageal stethoscope at various depths reveals that placement depth greatly affects the sounds. A depth of 28-32 cm is recommended for clinical use; S1, S2, and inspiratory and expiratory sounds have a high amplitude in that range.

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Although auscultation is commonly used as a continuous monitoring tool during anesthesia, the breath sounds of anesthetized patients have never been systematically studied. In this investigation we used digital audio technology to record and analyze the breath sounds of 14 healthy adult patients receiving general anesthesia with positive pressure ventilation. Sounds recorded from inside the esophagus were compared to those recorded from the surface of the chest, and corresponding airflow was measured with a pneumotachograph. The sound samples associated with inspiratory and expiratory phases were analyzed in the time domain (RMS amplitude) and frequency domain (peak frequency, spectral edge, and power ratios). There was a positive linear correlation (R2 > 0.9) between inspiratory flow and sound amplitude in the precordial and esophageal samples of all patients. The RMS amplitude of the inspiratory and expiratory sounds was approximately 13 times greater when recorded from inside the esophagus than from the surface of the chest in all patients at all flows (p < 0.001). The peak frequency (Hz) was significantly higher in the esophageal recordings than the precordial samples (298 +/- 9 vs 181 +/- 10, P < 0.0001), as was the 97% spectral edge (Hz) (740 +/- 7 vs 348 +/- 16, P < 0.0001). In the adult population esophageal stethoscopes yield higher frequencies and greater amplitude than precordial stethoscopes. Quantification of lung sounds may provide for improved monitoring and diagnostic capability during anesthesia and surgery.

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Forty-six adults undergoing dental procedures were monitored with a pulse oximeter for hypoxemia. Thirty-six patients received various amounts and combinations of central nervous system depressant drugs (barbiturates, sedatives, and narcotics) in addition to local anesthetics to produce a state of conscious sedation. Twenty-eight patients in the latter group received supplemental oxygen. Ten subjects served as a control group and received only local anesthesia without supplemental oxygen. Continuous monitoring by pulse oximetry revealed 151 episodes of mild, 132 of moderate, and 33 of severe arterial oxygen desaturation, although clinical signs of hypoxemia were absent. Patients with a body mass index greater than 30 or those with a smoking history greater than 30 pack-years were particularly prone to arterial oxygen desaturation.

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From poly(vinyl alcohol) precursors, various reactive carriers for the immobilization of enzymes were synthesized. As insoluble starting polymers, the following products were used: poly(vinyl alcohol), gels crosslinked with terephthalaldehyde, hydrolyzed beads of crosslinked poly(vinyl acetate), poly(vinyl acetate-co- ethylene) tubes coated with poly(vinyl alcohol), and poly(vinyl alcohol)-containing synthetic pulp. Reactive groups introduced into these carriers or methods for their activation included the diazonium- and isothiocyanato group, and the glutardialdehyde-, BrCN, 2, 4, 6-trichloro-s-triazien, and p-benzoquinone methods. Furthermore, SH-specific reactive groups such as N-substituted maleimide groups or activated mixed disulfides with 2-thiopyridyl groups could be introduced into PVA-polymers. Enzymes like hydrolases (e.g. papain, trypsin, chymotrypsin, urease), oxidoreductases (e.g. glucose oxydase, catalase, glucose-6-phosphate dehydrogenase) as well as the example of transferase hexokinase coimmobilized with glucose-6-phosphate dehydrogenase, were immobilized by reactive poly(vinyl alcohol) carriers. The properties of the immobilized enzymes were investigated.

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