By I. Randall. Bethany Bible College.
It has sensorimotor discount levitra soft 20mg without prescription erectile dysfunction pills nz, stage (birth to 24 months) generic 20 mg levitra soft fast delivery erectile dysfunction treatment dublin, knowledge is been found that children do not always reach the differ- gained primarily through sensory impressions and motor ent stages at the age levels he specified, and that their activity. Through these two modes of learning, experi- entry into some of the stages is more gradual than was enced both separately and in combination, infants gradu- first thought. However, Piaget remains the most influen- ally learn to control their own bodies and objects in the tial figure in modern child development research, and external world. The ultimate task at this stage is to many of his ideas are still considered accurate, including achieve a sense of object constancy, or permanence—the the basic notion of qualitative shifts in children’s think- sense that objects go on existing even when we cannot ing over time, the general trend toward greater logic and see them. This developing concept can be seen in the less egocentrism as they get older, the concepts of assim- child’s keen enjoyment of games in which objects are re- ilation and accommodation, and the importance of active peatedly made to disappear and reappear. The preoperational stage (ages two to six years) in- The most significant alternative to the work of Pi- volves the manipulation of images and symbols. One ob- aget has been the information-processing approach, ject can represent another, as when a broom is turned which uses the computer as a model to provide new in- into a “horsey” that can be ridden around the room, and a sight into how the human mind receives, stores, re- child’s play expands to include “pretend” games. Researchers using infor- guage acquisition is yet another way of manipulating mation-processing theory to study cognitive develop- symbols. Key concepts involved in the logical organiza- ment in children have focused on areas such as the grad- tion of thoughts—such as causality, time, and perspec- ual improvements in children’s ability to take in tive—are still absent, as is an awareness that substances information and focus selectively on certain parts of it retain the same volume even when shifted into contain- and their increasing attention spans and capacity for ers of different sizes and shapes. For example, they have found that the mains egocentric throughout both the preoperational and superior memory skills of older children are due in part sensorimotor stages. During the third, or concrete operational, stage (six or seven to 11 years of age), children can perform logical Today it is widely accepted that a child’s intellectual operations, but only in relation to concrete external ob- ability is determined by a combination of heredity and jects rather than ideas. Thus, although a child’s genetic inheri- measure, and they learn about the conservation of length, tance is unchangeable, there are definite ways that par- mass, area, weight, time, and volume. At this stage, chil- ents can enhance their children’s intellectual develop- dren can sort items into categories, reverse the direction ment through environmental factors. Other funda- mature, parents can both challenge and support the mental aspects of cognition are reasoning, the process by child’s talents. Although a supportive environment in which people formulate arguments and arrive at conclu- early childhood provides a clear advantage for a child, it sions, and problem solving—devising a useful represen- is possible to make up for early losses in cognitive devel- tation of a problem and planning, executing, and evaluat- opment if a supportive environment is provided at some ing a solution. Studies in Cognitive Growth: A Collabora- term memory provides the basis for one’s working tion at the Center for Cognitive Studies. The cognitive function that most distinctively sets Piaget, Jean, and Barbel Inhelder. The Growth of Logical humans apart from other animals is the ability to com- Thinking from Childhood to Adolescence. Of historical interest is the work of Benjamin Whorf (1897-1941), the proponent of the idea that the language people use determines the way in which they view the world. As of the late 1990s, most Cognition psychologists view the Whorfian hypothesis with skepti- A general term for the higher mental processes by cism, believing that language and perception interact to which people acquire knowledge, solve problems, influence one another. Language acquisition is another topic of debate, Cognition depends on the ability to imagine or rep- with some—including psycholinguist Noam Chomsky resent objects and events that are not physically present —arguing that all humans have innate language abilities, at a given moment. Cognitive functions include atten- while behaviorists stress the role of conditioning and so- tion, perception, thinking, judging, decision making, cial learning theorists stress the importance of imitation problem solving, memory, and linguistic ability. One of the most basic cognitive functions is the abil- Since the 1950s, cognitive psychology, which fo- ity to conceptualize, or group individual items together cuses on the relationship between cognitive processes as instances of a single concept or category, such as and behavior, has occupied a central place in psychologi- “apple” or “chair. The cognitive psychologist studies human framework for thought, allowing people to relate most perceptions and the ways in which cognitive processes objects and events they encounter to preexisting cate- operate on them to produce responses. People learn concepts by building prototypes to most cognitive psychologists is Jerome Bruner, who which variations are added and by forming and testing has done important work on the ways in which needs, hypotheses about which items belong to a particular cat- motivations, and expectations (or “mental sets”) affect egory.
Many staff are uncomfortable with applying economics to healthcare buy cheap levitra soft 20mg on-line erectile dysfunction medication new zealand, but while decisions should never be made solely on economic grounds purchase 20mg levitra soft with amex erectile dysfunction vasectomy, finance cannot be ignored where resources remain finite. Intensive care nursing relies on technology to support and monitor physiological function. Breathing and heartbeat can be replaced by technology (causing redefinition of death as absence of brainstem function), but intervention may prolong dying rather than prolong life: Rachels (1986) draws a distinction between living and the physical process of being alive. Technology may be used inappropriately; no treatment, intervention or observation should become ‘routine’. This much-used term is value-laden: what one person considers acceptable quality, another may not (e. Values vary between the extremes of preserving life at all costs, and always letting ‘nature’ take its course. Ethical principles Autonomy Beauchamp and Childress (1994) suggest that each ethical principle is part of a continuum. Autonomy, the first principle, is usually interpreted as ‘self-rule’—that is, making an informed free choice. Consent by relatives for mentally competent adults has no legal validity (Brazier 1992; Dimond 1995; Braithwaite 1996). Parents or guardians have the right to consent to treatment for children under 18 (Dimond 1995), but the 1989 Children’s Act and civil law precedent of ‘Gillick competence’ emphasise rights of children to make their own informed decisions provided they have achieved sufficient maturity to fully understand what is proposed (Brazier 1992). So one relatively young child may (legally) make more profound decisions than an older child. If in doubt, nurses should seek help to clarify the rights and duties of all concerned (most hospitals have legal advisors). The law assumes that healthcare staff will act in patients’ best interests (Brazier 1992). Actions in patients’ best interests may be condoned, but nonconsensual touch (including Intensive care nursing 140 any nursing/medical intervention without valid consent) is technically assault. The consent of relatives, while not legally binding, may provide an insight into the patient’s wishes, while building goodwill between relatives and staff. However, the relatives’ values may also differ, and extreme stress and guilt can result from believing they are making ‘life or death’ decisions. Advance directives (‘living wills’) state patients’ wishes for specific (stated) treatments to be withheld (e. Advance directives must necessarily anticipate scenarios where patients cannot express their wishes. However the ability of most people to make informed decisions about hypothetical situations is questionable (Ryan 1996); most consultants oppose withdrawing treatment only on the basis of advance directives (Grubb et al. Patients’ views may have changed since writing the document, especially if it is old (although this would not affect validity of a last will and testament). Nurses finding evidence of an advance directive (possibly through discussions with relatives) should alert unit managers and the multidisciplinary team. Non-maleficence Not doing harm has been fundamental to healthcare since the Hippocratic Oath, and restated in Nightingale’s (1980 ) Notes on Nursing, Roper et al. Benefits of invasive equipment may justify risks from infection; psychological dilemmas are often more complex. Healthcare workers may justify white lies or withholding truth and diagnoses as being in the patients’ and families’ best interests, while others may consider deliberate untruth or withholding information is unjustifiable (unethical). If life is sacrosanct, then death is presumably the greatest possible harm; if death is preferable to continued suffering, then life support can be harmful. Individual assessment of each patient can help nurses to understand what they would consider harmful; once identified, potential and existing harms (e.
Hyperbaric pressure can be discontinued once haemoglobin oxygen carriage is available (at most 20mg levitra soft sale erectile dysfunction age 16, usually a few hours) buy levitra soft 20mg cheap erectile dysfunction doctors in arizona. The complications of hyperbaric oxygen include: ■ evidence: is largely limited to enthusiastic anecdotes rather than controlled trials; ■ high atmospheric pressures: cause barotrauma to ears, sinuses and lungs, grand mal fits and changes in visual acuity (Oh 1997); ■ oxygen toxicity: if prolonged (Oh 1997); ■ monitoring: pulse oximetry has little value as oxygen carriage is not by haemoglobin (Pitkin et al. This may affect ventilation, inotropes and other infusions/mechanical support; ■ scarcity: few units have hyperbaric chambers, necessitating long-distance transfer of hypoxic patients. Implications for practice ■ modes discussed in this chapter may be rarely seen; where used, staff should take every opportunity to become familiar with their use ■ these modes are usually used with the sickest patients, so individual complications of each mode are compounded by complications of severe pathophysiologies; nursing care should be actively planned to optimise safety for each patient ■ visitors and patients may be anxious about use of rarer modes, or frightened by particular aspects (e. This chapter provides an introduction to these modes for staff unfamiliar with them or new to units where they are used. Whenever rarer modes or treatments are used the potential for unidentified complications is increased. Therefore the decision to use (or suggest) alternatives modes should be tempered by considerations of patient safety: ■ How will the patient benefit? Where unusual equipment is used, staff should take every reasonable opportunity to become familiar with it, but remember the focus of nursing should be the patient, not the machine. Alternative ventilatory modes 289 Useful contact Helpline for hyperbaric oxygen: 01705–822351, ext. Fewer nursing articles have appeared on these modes; Dirkes (1996) gives a reasonable summary of liquid ventilation, although discusses medical treatment rather than nursing care. Clinical scenario Gary Powers is a 22-year-old who, whilst working in construction, sustained a crush injury to his chest and head injury when a wall collapsed on top of him. Chest X-ray has revealed flail chest with multiple rib fractures, haemothoraxcis and lung contusions. When drug therapies cannot support cardiac failure, surgery is needed either to repair or replace damaged tissue. Hospitals not performing open heart surgery may still transfer patients to or receive patients from specialist centres. This chapter describes most open heart procedures, percutaneous (‘closed’) alternatives, means to support failing hearts (intra-aortic balloon pumps, ventricular assist devices), and transplant surgery. Much nursing care follows from problems and potential problems caused by surgical procedures; this chapter begins by briefly describing intraoperative procedures. Aortic dissection and aortic root repair, although not discussed in this text, share many of the approaches and problems of open heart surgery. In this chapter, ‘bypass’ refers to grafts; in practice, contexts often clarify intended meanings. The heart is isolated and either arrested (with cardioplegia) or slowed (with β-blockers, usually to about 40 bpm). Sternotomy repair with permanent wire loops (usually five—visible on X-rays) leaves a distinctive permanent skin scar. Sternal wounds and chest drain tubing can cause considerable postoperative pain, making patients reluctant to breathe deeply (predisposing to chest infection). Disconnection and reconnection of major vessels, together with surgery on heart tissue, exposes patients to possible air (micro)emboli, causing possible postoperative neurological and coronary dysfunction. Traditionally, cold cardioplegia (4–10°C) was used to reduce metabolism, but hypothermia causes ■ myocardial depression (‘stunning’) ■ ventricular dysrhythmias ■ increased blood viscosity ■ reduced cerebral blood flow ■ increased systemic and pulmonary vascular resistance ■ cell dysfunction and many other complications (Price & Donahue 1994; Barden & Hansen 1995). To prevent hypervolaemia, 2 units of blood are usually removed for postoperative autologous transfusion.
Progressive equilibrium between intracellular and extracellular ions impairs action potential generation buy generic levitra soft 20 mg erectile dysfunction treatment fruits. The accumulation of intracellular fatty deposits accelerates cell damage and rupture buy levitra soft 20 mg with mastercard erectile dysfunction treatment scams, with the kidneys, heart and liver being especially susceptible (e. Tissue tolerance to hypoxia varies; central nervous system neurons have high metabolic rates, relying on glucose for energy and can only tolerate a few minutes of ischaemia (hence cardiopulmonary resuscitation times); renal and hepatic cells can tolerate an hour’s ischaemia at normal body temperature (enabling safe isolation for most surgical procedures); hypothermia reduces metabolic rate, and so extends ischaemic toleration time (hence use of hypothermia for cardiac surgery). Cellular pathology 237 Microcirculation Most critical pathologies are fuelled by hypoperfusion from microcirculatory collapse (see Chapter 25). Vasoactive mediators (part of normal homeostasis) relax smooth muscle in arterioles, but venules remain constricted; the resulting pressure gradient forces plasma into interstitial spaces (oedema). Resulting haemoconcentration increases blood viscosity, which further reduces perfusion (see Chapter 18) and encourages thrombi formation. Although a brief overview is given below, most have similar interdependent effects (proinflammatory, procoagulopathic and cytotoxic) causing progressive multiorgan dysfunction. Neutrophil activation provokes oxygen-derived free radicals and protease production; oxygen radicals are discussed in Chapter 18. Cytokines Cytokines are chemical mediators of immunity which enhance inflammatory responses. They appear to cause various autoimmune disorders: meningitis, systemic lupus erythematosus, malaria, rheumatoid arthritis, Crohn’s disease, cystic fibrosis, asthma, multiple sclerosis, Intensive care nursing 238 atheroma, Alzheimer’s (Grimble 1994). Platelet activating factor In the early stages of shock, platelets release this mediator which ■ increases vascular permeability ■ increases smooth muscle contraction (arteriolarconstriction) ■ activates neutrophils ■ activates platelet surface adherence (accelerating hypercoaguable states) Myocardial depressant factor Released by the pancreas and spleen following lysosomal damage to cell proteins (e. Acute phase proteins Infection initiates the early release of proteins, including fibrinogen, alpha-1 protinase inhibitor, C-reactive protein and serum amyloid associated protein (Nowak & Handford 1996) to assist phagocytosis. Prostaglandin E1 is used therapeutically to reduce platelet adhesion and decrease systemic vascular resistance, so improving tissue perfusion (Appel et al. Complement Activated by endotoxaemia, the complement combination (C5b, 6, 7, 8, 9) forms a Membrane Attack Complex, part of antigen-antibody reactions to foreign proteins (especially gram negative bacteria). With systemic pathologies, such as shock, increased vascular permeability (C5), inappropriate neutrophil activation and gross fluid shifts complicate, rather than resolve, progression. Free radicals are molecules with one or more unpaired electrons in their outer orbit, which makes them inherently unstable, reacting readily with other molecules to pair the free electron. The reaction of two radicals eliminates both, but reactions between radicals and non-radicals produces a further radical. Reactivity is indiscriminate, so that although their lifespan lasts only microseconds, chain reactions may be thousands of events long (Davidson & Boom 1995) causing the autocatalysis underlying most critical illnesses. Oxygen radicals are particularly destructive, with oxidation modifying proteins (Hipkiss 1989), including cell membrane phospholipid. Free oxygen radicals are released with hyperoxia (Davidson & Boom 1995), so that prolonged high FiO2 (above 0. Intensive care nursing 240 Hypoxic vascular epithelium releases endogenous nitric oxide (see Chapter 28); widespread tissue hypoxia (shock) therefore causes widespread nitric oxide release and systemic vasodilation. Cells surviving initial injury exist in grossly disordered internal environments; anaerobic metabolism causes peripheral accumulation of metabolic acids, free radicals, oxidative enzymes (e. Reperfusion injury can result from toxic products being flushed into the central cardiovascular system during recovery, potentially causing secondary (reperfusion) damage. Calcification Necrosis leads to microscopic calcium deposits; accumulation through persistent injury causes progressive tissue damage and rigidity, especially in renal, pulmonary, cardiovascular and gastric cells (Nowak & Handford 1996). Implications for practice ■ most critical pathologies originate at microcellular rather than macro-system level; understanding these processes enables nurses to understand the pathologies and treatments covered in many of the other chapters (e.
10 of 10 - Review by I. Randall
Votes: 39 votes
Total customer reviews: 39