Reducing the risks of ventilator-associated infections.

Mechanically ventilated patients are at high risk for developing nosocomial pneumonia. This article reviews the pathogenesis of ventilator-associated infections and ways nurses can intervene to reduce the risks to patients and to themselves.

D(2), but not D(1) dopamine receptor agonists potentiate cannabinoid-induced sedation in nonhuman primates.

In primates, CB(1) cannabinoid receptor agonists produce sedation and psychomotor slowing, in contrast to behavioral stimulation produced by high doses of dopamine receptor agonists. To investigate whether dopamine agonists attenuate the sedative effects of a cannabinoid agonist in monkeys, we compared the effects of D(1) or D(2) dopamine receptor agonists on spontaneous behavior in three to six cynomolgus monkeys (Macaca fasicularis) alone and after administration of a low dose of the CB(1) agonist levonantradol. Alone, the CB(1) cannabinoid receptor agonist levonantradol (0.01-0. 3 mg/kg) induced sedation, ptosis, and decreased locomotor and general activity. Alone, D(2)-type dopamine agonists quinelorane (0. 001-1.0 mg/kg; n = 4) or pergolide (0.01-1.0 mg/kg) or a D(1) dopamine agonist 6-chloro-7,8-dihydroxy-1-phenyl-2,3,4, 5-tetrahydro-3-allyl-[1H]-3-benzazepine (0.3-3.0 mg/kg) produced either no effect or promoted hyperactivity. Thirty minutes after administration of a threshold dose of levonantradol (0.03 mg/kg), D(2)-type agonists, but not the D(1) agonist, precipitated marked sedation, ptosis, and decreased general activity and locomotor activity. These data inducate the following: 1) D(2,) but not D(1) dopamine agonists, potentiate sedation in monkeys treated with a CB(1) cannabinoid agonist, at doses of agonists that alone do not produce sedation; 2) the threshold dose for cannabinoid-induced sedation is reduced by D(2) agonists, but not by a D(1) dopamine agonist, differentiating D(1) and D(2) dopamine receptor linkage to cannabinoid receptors; and 3) modulation of D(2) dopamine receptor activity by a nonsedating dose of a cannabinoid agonist has implications for the pathophysiology and treatment of dopamine-related neuropsychiatric disorders and drug addiction. Cannabinoid agonists and D(2) dopamine agonists should be combined with caution.

Co-oximetry.

The adequacy of tissue oxygenation depends on the interaction of many factors. Assuming the presence of sufficient tissue perfusion, oxygenation failure must be caused by depressed respiratory efficiency (shunt or other ventilation/perfusion mismatch), inadequate FIO2/PaO2 relationships (alveolar-capillary diffusion deficits, for example), or oxygen transport difficulties (hemoglobin loading/unloading dysfunction). When presented with patients whose respiratory distress is not alleviated by application of increasing levels of FIO2 and seemingly adequate SaO2 values, one must look toward less obvious reasons for the disparity between subjective and objective findings. Early response by clinicians to situations such as those just mentioned should include a survey and analysis of hemoglobin status. It is important to note that meaningful co-oximetry results depend on the quality of the patient history and other laboratory tests to rule out factors that might affect the co-oximetry results. Good preparation of the sample is essential to ensure that adequate hemolysis has occurred and that the sample was not contaminated prior to analysis. A well designed and executed program of preventive maintenance and QA is important. It should include preparation and sampling as well as technique and instrument integrity. All of these are essential for safe, effective, and accurate determination and dissemination of this important clinical information.

Wernicke and Alzheimer on the language disturbances of dementia and aphasia.

Signs of language dysfunction in dementia of the Alzheimer's type (DAT) and in the aphasic syndromes of transcortical sensory aphasia and Wernicke's aphasia are superficially similar. The unresolved question concerning the extent to which the language disturbances of DAT are "aphasic" is linked to a more fundamental question concerning the relation of language to thought, given that aphasia is often defined as language disturbance without disturbance of intellect, and dementia as dissolution of intellectual function, of which language forms an integral part. In this paper we explore the historical roots of today's debate by analyzing the original case studies of Wernicke (1874) and Alzheimer (1907, 1911). Although each of these neurologists described similar patterns of language disturbance, they drew different conclusions. Wernicke argued for a distinction between language and thought and between the language disturbances of aphasia and those of dementia. Alzheimer continued the then dominant paradigm of aphasia in describing the language disturbances of his demented patients as aphasic. Paradoxically his conclusion makes him appear, in contrast to Wernicke, to argue for the identity of the language disturbances of aphasia and dementia. Yet he himself acknowledged that the presence of focal language symptoms arising from diffuse degenerative pathology was indeed problematic. We conclude that today's discussion could profitably be refocused on the question which emerges from the original works of Wernicke and Alzheimer, which Alzheimer himself asked, and which remains unanswered: How can diffuse cerebral pathology give rise to a pattern of language deficit virtually identical to that of a focal lesion?

Needs: importance and satisfaction in respiratory therapy personnel.

Using Maslow's hierarchy of needs as a base, this article attempts to determine the motivational level of respiratory therapy personnel. Also analyzed was the importance of these needs to the individuals studied. The instrument used to obtain the necessary data was a questionnaire designed to indicate a mathematical score relevant to a person's position in the hierarchy. This instrument was designed by Lyman Porter and is called the Porter needs-satisfaction index (PNSI). The respondents, who were representatives of all classes of respiratory therapy personnel, showed high levels of satisfaction in areas concerned with helping others, autonomy, and prestige. They ranked ability to help others, self-fulfillment, and feelings of accomplishment as highly important. Further analysis of the questionnaires is presently under way. It is hoped that data relative to position in the hierarchy based on demographic data will soon be available.