By M. Kerth. University of Idaho.
Soft tissue injections around the scapula or into an intercostal muscle have perforated lungs cheap brahmi 60caps 5 medications post mi. Joint injections by those not properly trained have caused destructive septic arthritis best brahmi 60 caps treatment bursitis. These and similar misadventures have led to lawsuits that are very difficult to defend. The Language Barrier The problems related to language barriers are well known to phy- sicians. Patients with limited English skills cannot be denied health care or in any way be discriminated against by health care providers. In 2000, President Clinton issued Executive Order 13166, requiring equal access to federally funded health care services for patients with limited English proficiency. A language barrier will probably not shield a physician from allegations of negligence. In one recent case, a physician failed to diagnose a subarachnoid hemorrhage because he could not understand the history of onset or severity of a headache. Interpreters on the telephone or, bet- ter still, in the office are invaluable. Before discharging a patient, a physician should be certain that he or she understands the medical problems and that the patient understands the necessary advice and follow-up. SUMMATION At any given time, 15–20% of physicians are defendants in malprac- tice lawsuits. The average lawsuit takes more than 3 years from incep- tion to resolution. The experience can destroy a physician’s health, family relationships, standing in the community, self-confidence, and financial security. There have even been suicides where objective evaluation indicated that the physician was not guilty of wrongdoing. Risk managers have been criticized for advising strategies that are too time-consuming. New laws, rules, and court decisions continue to create additional responsibilities and risks for physicians. Finally, it should be kept in mind that a family physician’s best friends in a malpractice lawsuit are the contemporaneous, thoughtful, clearly written medical record and a supportive, competent, caring nurse. Chapter 9 / Emergency Medicine 101 9 Emergency Medicine Michael Jay Bresler, MD, FACEP SUMMARY This chapter reviews some general medical and legal principles, most of which are important regardless of medical specialty. They are particularly relevant to emergency physicians but are also important to physicians from other specialties who treat patients in the emergency department (ED). I then discuss some specific emergency medical conditions that often result in litigation. The topics presented are not meant to be an exhaustive list of potential liability problems, but rather a sample of some of the more com- mon issues that confront physicians and their patients. Key Words: Emergency; emergency medicine; emergency depart- ment; medical-legal; risk management. Emergency physicians revel in the excitement, chaos, and challenge presented by emergency patients. Unfortunately, we are also appreciated by another class of people—plaintiff attor- neys. They like us precisely because we practice in a hectic, somewhat From: Medical Malpractice: A Physician’s Sourcebook Edited by: R. They like us because our patients often are either very ill or will become very ill. And they like us because they know that we cannot always predict which of our patients will become very ill or die in the near future. Although we will be emphasizing the avoidance of liability, remem- ber that the best defense, as is often said, is to do the right thing.
The fluid enters the fetal blood purchase brahmi 60caps with amex symptoms gastritis, and the Yolk Sac waste products it contains enter the maternal blood in the pla- The yolk sac is established during the end of the second week as cells from the trophoblast form a thin exocoelomic (ek'so-se˘- Down syndrome: from John L order 60 caps brahmi overnight delivery medications bladder infections. Developmental © The McGraw−Hill Anatomy, Sixth Edition Development Anatomy, Postnatal Companies, 2001 Growth, and Inheritance 764 Unit 7 Reproduction and Development Decidua basalis Chorion frondosum Maternal vein Maternal Umbilical artery Chorion cord Amnion Amniotic sac containing amniotic fluid Placenta FIGURE 22. Blood from the embryo is carried to and from the chorion frondosum by the umbilical arteries and vein. The maternal tissue between the chorionic villi is known as the de- cidua basalis; this tissue, together with the villi, form the functioning placenta. Attached to It also contributes to the development of the urinary bladder. After birth, the urachus becomes a fibrous cord called form in the wall of the yolk sac. During the fourth week, they the median umbilical ligament that attaches to the urinary bladder. It contributes to the formation of the placenta as small fin- pregnancy advances. Eventually, it becomes very small and gerlike extensions, called chorionic villi, penetrate deeply into the serves no additional function. But those chorionic villi on the sur- Allantois face toward the uterine cavity gradually degenerate, producing a The allantois forms during the third week as a small outpouch- smooth, bare area known as the smooth chorion. As this occurs, ing, or diverticulum, near the base of the yolk sac (see the chorionic villi associated with the uterine wall rapidly increase fig. It remains small but is involved in the formation of in number and branch out. Blood does not flow directly between these two portions, but because their membranes are in close proximity, certain substances diffuse readily. When fully formed, the placenta is a reddish brown oval disc with a diameter of 15 to 20 cm (6 to 8 in. Exchange of Molecules across the Placenta The two umbilical arteries deliver fetal blood to vessels within Uterine wall the villi of the chorion frondosum of the placenta. This blood circulates within the villi and returns to the fetus via the umbili- Amniotic fluid cal vein (fig. Maternal blood is delivered to and drained from the cavities within the decidua basalis, which are located Amniotic sac between the chorionic villi. In this way, maternal and fetal blood Placenta are brought close together but do not normally mix within the placenta. The placenta serves as a site for the exchange of gases and other molecules between the maternal and fetal blood. Oxygen diffuses from mother to fetus, and carbon dioxide diffuses in the opposite direction. Nutrient molecules and waste products like- wise pass between maternal and fetal blood. In this procedure, amniotic fluid containing suspended cells is withdrawn for examination. It utilizes about netic diseases can be detected prenatally by this means. In fact, the rate of protein synthesis is actually higher in the placenta than it is in the fetal liver. The verting biologically active molecules (such as hormones and villous chorion becomes highly vascularized with embryonic drugs) into less active, more water-soluble forms. In this way, po- blood vessels, and as the embryonic heart begins to function, em- tentially dangerous molecules in the maternal blood are often bryonic blood is pumped in close proximity to the uterine wall. Chorionic villus biopsy is a technique used to detect genetic Some substances ingested by a pregnant woman are able to disorders much earlier than amniocentesis permits. In chori- pass through the placenta readily, to the detriment of the fetus. Ex- chorion, and a sample of chorionic villus is obtained by suction or cessive nicotine will stunt the growth of the fetus; heroin can lead to cutting.
Indianapolis cheap brahmi 60 caps with amex medicine disposal, Indiana Professor of Physiology and Biophysics Indiana University School of Medicine Paul F buy generic brahmi 60caps on-line symptoms anxiety. Indianapolis, Indiana Director, Center for Reproductive Sciences University of Kansas Medical Center John C. Kansas City, Kansas Associate Professor of Neurology and Physiology and Biophysics Indiana University School of Medicine Patrick Tso, Ph. Indianapolis, Indiana Professor of Pathology University of Cincinnati School of Medicine Bruce E. Cincinnati, Ohio Associate Professor of Physiology Indiana University School of Medicine C. Indianapolis, Indiana Research Pharmacologist, Military Ergonomics Division USARIEM James McGill, M. Natick, Massachusetts Assistant Professor of Medicine Indiana University School of Medicine Jackie D. Indianapolis, Indiana Professor and Chairman, Department of Physiology Ohio State University College of Medicine Columbus, Ohio vii PART I Cellular PhysiologyCellular Physiology CHAPTER Homeostasis and Cellular Signaling Patricia J. Different modes of cell communication differ in terms of and how they are regulated and integrated. Chemical signaling molecules (first messengers) provide function and survival of the organism. Homeostasis is the maintenance of steady states in the clude ions, gases, small peptides, protein hormones, body by coordinated physiological mechanisms. Receptors are the receivers and transmitters of signaling body’s responses to changes in the environment. Second messengers are important for amplification of the while equilibrium represents a balance between opposing signal received by plasma membrane receptors. Cellular communication is essential to integrate and coor- receptors that participate in the regulation of gene ex- dinate the systems of the body so they can participate in pression. It is a broad field that encompasses many dis- modynamic terms, muscle contraction is analyzed in terms of ciplines and has strong roots in physics, chemistry, and math- forces and velocities, and regulation in the body is described ematics. Physiologists assume that the same chemical and in terms of control systems theory. Because the functions of physical laws that apply to the inanimate world govern living systems are carried out by their constituent structures, processes in the body. They attempt to describe functions in knowledge of structure from gross anatomy to the molecular chemical, physical, or engineering terms. In recent years, we have seen many advances in our understanding of phys- Lungs iological processes at the molecular and cellular levels. In higher organisms, changes in cell function always occur in Alimentary the context of a whole organism, and different tissues and tract organs obviously affect one another. The independent ac- Kidneys tivity of an organism requires the coordination of function at all levels, from molecular and cellular to the organism as a whole. An important part of physiology is understanding Internal how different parts of the body are controlled, how they in- environment teract, and how they adapt to changing conditions. For a person to remain healthy, physiological conditions in the body must be kept at optimal levels and closely reg- ulated. Regulation requires effective communication be- Body cells tween cells and tissues. This chapter discusses several top- ics related to regulation and communication: the internal environment, homeostasis of extracellular fluid, intracellu- Skin lar homeostasis, negative and positive feedback, feedfor- ward control, compartments, steady state and equilibrium, intercellular and intracellular communication, nervous and endocrine systems control, cell membrane transduction, and important signal transduction cascades. Exchanges of matter and energy between the body and THE BASIS OF PHYSIOLOGICAL REGULATION the external environment (indicated by arrows) occur via the gas- trointestinal tract, kidneys, lungs, and skin (including the special- Our bodies are made up of incredibly complex and delicate ized sensory organs). It is clear that conditions and processes in the body must be closely maintain a relatively constant internal environment. A Stable Internal Environment Is Essential for Normal Cell Function Homeostasis Is the Maintenance of The nineteenth-century French physiologist Claude Steady States in the Body by Bernard was the first to formulate the concept of the inter- Coordinated Physiological Mechanisms nal environment (milieu intérieur). He pointed out that an ex- ternal environment surrounds multicellular organisms (air The key to maintaining stability of the internal environ- or water), but the cells live in a liquid internal environment ment is the presence of regulatory mechanisms in the body. Most body cells are not directly ex- In the first half of the twentieth century, the American posed to the external world but, rather, interact with it physiologist Walter B. Cannon introduced a concept de- through the internal environment, which is continuously scribing this capacity for self-regulation: homeostasis, the renewed by the circulating blood (Fig.
This is thought gradually to dissipate the ionic gradient that is needed for the transporter to take up 5-HT into the neuron and so culminates in the outward transport of 5-HT into the synapse (Rudnick 1997) cheap 60caps brahmi free shipping medicine quetiapine. This action is compounded by their disruption of the vesicular transporters (VMATs) since purchase brahmi 60caps without prescription medications 122, once they gain access to the neuron, they diminish the proton gradient required for the VMATs to function properly, possibly because they are weak bases (see Chapter 8; Fig. This leads to leakage of 5-HT into the cytoplasm where its ensuing increased concentration ensures that a large pool is available for its retrotransport into the synapse. Recent evidence indicates that the 5-HT transporter is subject to post-translational regulatory changes in much the same way as neurotransmitter receptors (Blakeley et al. Protein kinase A and protein kinase C (PKC), at least, are known to be involved in this process. Phosphorylation of the transporter by PKC reduces the Vmax for 5-HT uptake and leads to sequestration of the transporter into the cell, suggesting that this enzyme has a key role in its intracellular trafficking. Since this phosphorylation is reduced when substrates that are themselves transported across the membrane bind to the transporter (e. Possibly, this process serves as a homeostatic mechanism which ensures that the supply of functional transporters matches the demand for transmitter uptake. Thus, such inhibitors would reduce 5-HT uptake both by their direct inhibition of the transporter and by disinhibition of its phosphorylation (Ramamoorthy and Blakely 1999). In contrast, activation of adenosine (A3) receptors seems to upregulate the transporter, possibly through the PKG, NO/cGGP pathway. Glycosylation sites have also been identified on the transporter and recent findings suggest that the sex steroids, estradiol and testosterone increase transcription of the transporter gene and, in turn, the density of transporters in the DRN but not the MRN (McQueen et al. Although it is not yet clear whether this involves a direct effect on transporter gene expression, this finding does suggest that transporters associated with these two groups of neurons are subject to different control mechanisms. Many studies have attempted to show changes in 5-HT uptake or the density of transporters either in depressed patients, or after treatment with antidepressants. Most have found a reduction in the density of uptake sites, labelled with the tricyclic reuptake inhibitor, [3H]imipramine, in depression. However, there appears to be no change in the density of uptake sites when these are labelled with the selective serotonin reuptake inhibitor, [3H]paroxetine. Another problem is that, even in studies showing a reduction in transporter density, there are no consistent changes in 5-HT uptake. More recently, research has been directed towards a search for genetic polymorphisms of the 5-HT transporter gene that might account for disorders including depression, bipolar disorder, anxiety, substance abuse and autism. So far, no certain links with either the expression of, or vulnerability to, any disorder have emerged. One drug that seems to cause quite marked, long-term changes in 5-HT transporter function is MDMA. Interestingly, fenfluramine, another 5-HT-releasing agent, does not seem to have this effect. It has been suggested that loss of transporters in users of MDMA is due to the death of 5-HT neurons and that this is evidence for its neurotoxic effects. This toxicity is thought to be mediated by the formation of quinones and then free radicals from the metabolites of MDMA, although there are alternative explanations (see Sprague, Everman and Nichols 1998) and some individuals still dispute that this drug is actually neurotoxic in humans. At the very least, there is accumulating evidence for long-term deficits in cognitive and neuroendocrine function in users of MDMA and, of even greater concern, it is not known whether these are reversible. METABOLISM 5-HT is metabolised primarily by MAO to 5-hydroxyindoleacetic acid (5-HIAA) (Fig. In vitro, 5-HT is the preferred substrate for the MAOA, rather than the MAOB isoenzyme (see Chapter 8) and this appears to be the case in vivo since MAOA, but not MAOB, knock-out mice have increased concentrations of 5-HT in the brain. Obviously, because of its indole nucleus, 5-HT is not a substrate for the enzyme COMT which metabolises the catechol derivatives, dopamine and noradrenaline. However, other metabolic products of 5-HT are theoretically possible and one, 5-hydroxytryptophol, 5-HYDROXYTRYPTAMINE 197 which results from the reduction of its intermediate metabolite, 5-hydroxyindoleacetal- dehyde, instead of oxidation to 5-HIAA, has been identified in the brain. The comparatively straightforward link between 5-HT and its primary metabolite, 5-HIAA, encouraged many researchers to use changes in the ratio of tissue concentrations of 5-HIAA and 5-HT as an index of the rate of release of 5-HT ex vivo.