Informed consent revisited

The resurgence in mycobacterial infection worldwide has led to renewed attention to the pathogenesis of Mycobacterium species. The purpose of this study was to characterize the infection of alveolar macrophages (AMs) by nonopsonized Mycobacterium bovis, and to elucidate the mechanism by which a differential infection of subpopulations of AM may occur. A difference in susceptibility to Mycobacterium bovis infection of subpopulations of AMs was observed, such that the least dense cells were the least susceptible (21.4 +/- 10.7%) and the most dense cells were the most readily infected (61.8 +/- 5.6%). The percentage of AMs staining for CD14 receptors showed a similar differential distribution, with fewer of the least dense cells expressing CD14 and a greater percentage of the most dense cells staining for CD14 receptor expression. To investigate the role of CD14 receptors in the infection of AMs, anti-CD14 antibody was added to the cell cultures. Infection of AM by Mycobacterium bovis was blocked by up to 60.2% by anti-CD14 antibody but not by isotype control antibody. The results of this study suggest that Mycobacterium bovis selectively infects AM subpopulations, specifically those with the greatest expression of CD14, a putative receptor mechanism for Mycobacterium bovis infection of porcine AM.     

Informed consent for phase I studies: evaluation of quantity and quality of information provided to patients

BACKGROUND: The process by which patients are informed and their consent is obtained in phase I trials has thus far been only marginally studied. Since 1986 we have followed an oral procedure, consisting of three consecutive conversations in which the investigator responsible for phase I studies, the research nurse and the patients' relatives and/or friends also participate, followed by the patients signing of a written consent form. It is required that six items of information considered essential by our staff be conveyed to patients by the responsible investigator. Meerwein's model, which defines three main dimensions of the informing process (the information itself, the emotional and interactive aspects), has been studied to ascertain whether it can be applied to evaluate the quality of the information proffered. METHODS: Thirty-two conversations were taped, transcribed and evaluated by one psychiatrist and one psychologist. A quantitative analysis of information was performed by calculating the number of patients to whom the essential items of information had been conveyed. The qualitative analysis was performed by rating on a five-point scoring system, from 1 (very bad) to 5 (excellent), the three dimensions of the informing process for each patient and by calculating for each dimension the mean score of the constituent items. RESULTS: Complete information about the characteristics of the phase I drug and the modalities of the treatment and follow up was given to almost 80% of the patients. All but one of the items of the information dimension scored 3.5 or higher, with the one related to the assessment by the doctor of the patient's understanding at the end of the consultation scoring less than 3 in 53% of the patients. All items of the emotional dimension scored higher than 3.5. Greater difficulty was encountered by the physician with the interactive dimension, the lowest mean scores being reported on the items related to the doctor's awareness of the indirectly expressed anxieties of the patients. In 71% of the consultations the three dimensions of information scored more than 3 and balanced one another, indicating a successful consultation by the Meerwein model. CONCLUSIONS: The informed consent procedure applied was satisfactory from a quantitative point of view, and the main items of information were acceptable to the patients. Meerweins's model proved to be applicable and useful for identifying pitfalls in communication. Greater attention should be paid to the indirect messages and implied criticisms of the patients to improve their participation in decision making. Physicians should become more skillful in providing adequate information and improve their methods of communication.     

Informed consent meets managed care

This article evaluates the correlation between injury occurrence, step test estimated maximal aerobic capacity (VO2max), and body composition in a high-frequency manual materials handling task. The study used 212 highly trained male manual material handlers working for a major materials handling company. Three locations across the United States (western, midwestern, and southeastern) were chosen based on similarity of size and function. An estimated maximal aerobic capacity was obtained for each participant using a submaximal bench step protocol. Also, a percentage body fat estimation was randomly obtained for approximately 25% of the participants. The correlation between injury occurrences, absolute VO2max, relative VO2max, and percentage body fat were analyzed. Also, the relationship between both VO2max estimations and percentage body fat was analyzed. Finally, the correlation between location VO2max and percentage body fat was studied. Results indicated no significant difference between absolute VO2max, injury, or percentage body fat. Relative VO2max suggested a significant relationship with injury occurrences and body composition. Body composition also indicated a significant correlation with injury occurrences. Finally, location played a significant factor in injury occurrence, step test estimated VO2max, and estimated body composition. This investigation demonstrates significant evidence of the predictability of employee injury occurrence and the fitness estimation methods used. In a high-frequency manual materials handling task, high occurrences of injury were significantly correlated with low estimated relative maximal aerobic capacity and high estimated percentage body fat.     

Informed consent: a dialogue

Legal precedents and current approaches of the courts to the issue of informed consent in cases of urographic contrast media injection are considered. Radiologists ought to inform their patients of the possibility of an idiosyncratic reaction to contrast medium injection.     

Informed consent and home birth

The history and purpose of informed consent are explored and its legal components are detailed. Recommendations are given to meet the criteria for informed decision-making at home, including discussion of unusual circumstances. The nature of assistance at childbirth, especially at home, is explored in relation to legal obligations. The article includes some observations on cultural dissonance regarding informed consent. Finally, the authors recommend a focus on a therapeutic alliance with the client as the best outcome of effective informed consent and as the second best preventive measure against malpractice, the first being competent care.     

Informed consent for epidural analgesia in labor

Characteristics and reproducibility of bulbocavernosus reflex (BCR) and pudendal somatosensory evoked potentials (PSEP) elicited by mechanical stimulation in children were tested. Twenty-five male children aged 5-14 years without uroneurological complaints were enrolled in the study. In addition to electrical stimulation, a specially constructed electromechanical hammer triggered by an oscilloscope was used for mechanical stimulation of distal penis. All responses were detected by surface electrodes. The latencies and amplitudes of averaged as well as latencies of single BCR on single and double electrical stimuli were determined. Mechanical stimulation was described as much less unpleasant than electrical stimulation. Both mechanical/electrical stimulation elicited consistent and reproducible responses in high percentages of children (BCR: average, 80%/71%, single, 94%/100%; PSEP: 96%/96%, respectively). BCR latencies were significantly longer and PSEP amplitudes were significantly higher on mechanical stimulation. The compliance with mechanical was much better than with the electrical stimulation and the former can be recommended for clinical use. The effective mechanical stimulus delivered by a particular mechanical stimulator has a characteristic 'delay' (as to the actual point of triggering the oscilloscope ray) which influences the latency reading of responses; appropriate control data are therefore necessary.