I. Candela. Shaw University.
Virtues are indispensable both in making clinical decisions and carrying them out cheap wellbutrin 300mg line, and suggestions for nurturing them are given in conclusion. CHAPTER 1 COGNITIVE SEMANTIC STRUCTURES IN INFORMAL MEANS/ENDS REASONING "The physician is lost who would guide his activities of healing by building up a picture of perfect health, the same for all and in its nature complete and self-enclosed once for all. The forms are thus independent of the attitude taken by the thinker, of his desire and intention. This distinction has become important in assessing how best to resolve clinical problems in medicine. A useful working distinction between formal and informal reasoning closely follows that of Dewey quoted above, between "formal logic" and "actual thinking. The intent is to show how such structures contribute to our multiple senses of causation, and therefore inform diagnostic and treatment actions. The use of standards, of course, rests upon the identification of commonalities among situations and often, indeed, upon forcing them into common molds. Formal means/ends reasoning requires not only the universalization of particulars but also the quantification of 9 10 CHAPTER 1 qualities. The standardization project involves applying one or another variant of economic rationality to decision making. All of the varying formulae, however, make similar assumptions about the nature of entities, relations and categories of entities and relations, as well as similar assumptions about the assessment of value and the rules of reason. Formal means/ends reasoning demands that particular entities must be classifiable according to their essential features, and that entities having the same essential features can be treated in a protocol as identical. Clinical situations amenable to standardization must be replicable ensembles of such entities which can also be treated as identical. Additionally, outcomes of professional work need to be specifiable ensembles which can be classified and thought of generically. Just as situations must be specified, assigned to categories, and dealt with according to category assignment, there must also be a formula for valuation.
When the assessment of volume status by diet and exercise therapy buy wellbutrin 300 mg amex, no special preoperative becomes critically important, it is often necessary to preparation is required. Hyperglycemia can be effec- measure pulmonary capillary wedge pressure using a tively treated with supplemental short-acting insulin Swan–Ganz catheter. The patients receiv- Intravenous ﬂuid administration must be adjusted ing oral hypoglycemic medications should have these for the older surgical patient because there is a decline held on the day of the operation. Hyperglycemia can be in both total body water and intracellular water with treated with short-acting insulin. For men between 65 and 85 years of age insulin, several management regimens are possible. More commonly, for lular volume is approximately 20% to 25% of body patients normally treated with a single dose of insulin weight. In the absence of acute stress and conditions each day, one-half to two-thirds of the usual dose of known to affect salt and water balance, the daily meta- insulin is given on the morning of surgery, and a glucose- bolic requirements per liter of intracellular ﬂuid are as containing intravenous solution is administered at a rate follows: of 5 to 10 g glucose per hour. For patients who are normally managed with multiple Water, 100 mL does of insulin throughout the day, one-third the usual Energy, 100 kcal morning dose is administered on the morning of sur- Protein, 3 g gery, and a glucose-containing solution is infused intra- Sodium, 3 mmol 89 venously. Blood sugar control is easier if a constant rate Potassium, 2 mmol of infusion of the glucose solution is maintained while For example, an 80-year-old woman weighing 40 kg has nonglucose-containing intravenous ﬂuids are used to an estimated intracellular volume of 10 L. Additional nance requirements would be 1 L water, 1000 kcal, 30 g doses of regular insulin should be administered to control protein, 30 mmol sodium, and 20 mmol potassium. Fluid blood sugar levels; a 6-h interval between glucose meas- and electrolyte status must be closely monitored and urements is commonly used. In addition to meticulous adjusted according to the response of the patient and the attention to blood sugar levels, it is important to monitor development of other pathophysiologic conditions. Myocardial ischemia can be silent and Endocrine Disorders may be detected unexpectedly on postoperative electro- Diabetes mellitus, usually type II, is common among cardiograms. It has been estimated that of diabetic Thyroid disease is not as prevalent as diabetes but, if patients undergoing surgery, more than 75% are over the undetected, can result in major complications periopera- age of 50. The prevalence of hypothyroidism in hospitalized ment of surgical patients but also predisposes the patient older patients has been reported to be 9. With the stress and tissue injury of tain a high index of suspicion for thyroid illness in this surgery, there is an increase in many of the counterregu- population.
Vertical Binocular Diplopia Blowout fracture of orbital floor with entrapment of the inferior rectus muscle Thyroid orbitopathy with tight inferior rectus muscle Ocular myasthenia Cranial nerve III (oculomotor) palsy Cranial nerve IV (trochlear) palsy Skew deviation Horizontal Binocular Diplopia Blowout fracture of medial orbital wall and entrapment of the medial rectus muscle Thyroid orbitopathy with tight medial rectus muscle Ocular myasthenia Internuclear ophthalmoplegia Convergence insufficiency Decompensated strabismus Cranial nerve III (oculomotor) palsy Cranial nerve VI (abducens) palsy Tsementzis order 300 mg wellbutrin mastercard, Differential Diagnosis in Neurology and Neurosurgery © 2000 Thieme All rights reserved. Ptosis 95 Ptosis Congenital Isolated Drooping is unilateral in 70% of congenital ptosis cases Familial Very rare, bilateral Sympathetic denerva- Congenital Horner’s syndrome tion Anomalous synkinesis Marcus Gunn phenomenon, jaw winking between cranial nerves III and V Blepharophemosis syn- dromes Neonatal myasthenia Neurogenic E. Acute Ophthalmoplegia 97 Brain tumors Brain stem glioma, craniopharyngioma, pituitary ade- noma, nasopharyngeal carcinoma, lymphoma, pineal region tumors Idiopathic cranial nerve Transitory nerve palsy, attributed to a viral infection palsy and affecting the abducens nerve more often than the oculomotor or trochlear nerves Myasthenia gravis And other pharmacological or toxic causes of neuro- muscular blockade Orbital – Tumors Dermoid cyst, hemangioma, metastatic neuroblas- toma, optic glioma, rhabdomyosarcoma – Inflammatory dis- Tolosa–Hunt syndrome, orbital pseudotumor, sarcoid ease Trauma E. The MLF lesion produces disconjugate eye movements and diplopia on lateral gaze, since impulses to the lateral rectus travel abnormally, whereas those to the medial rectus are intact. Brain stem infarction Most common in the older population; the syndrome is unilateral, and is caused by occlusion of the basilar artery or its paramedian branches Multiple sclerosis Most common in the young adults, especially when the syndrome is bilateral Intrinsic and extra-axial E. Unilateral Sudden Visual Loss 99 Vertical Gaze Palsy Tumors – Pineal area – Midbrain – Third ventricle Aqueduct stenosis and hydrocephalus Infarction or hemorrhage of the dorsal midbrain Head trauma Multiple sclerosis Miller–Fisher syndrome Vitamin B12 or B1 deficiency Neurovisceral lipid storage diseases – Gaucher’s disease – Niemann–Pick disease, type C Congenital vertical oculomotor apraxia The syndrome can be mimicked by: – Progressive supranuclear palsy – Thyroid ophthalmopathy – Myasthenia gravis – Guillain–Barré syndrome – Congenital upward gaze limitation Unilateral Sudden Visual Loss Vascular disturbances Ischemic optic atrophy Pallor of the optic nerve head, pale retinas, pseudo- due to arteriosclerosis papilledema and incomplete blindness are the promi- nent diagnostic features Transient monocular Stenosis of the internal carotid artery or cardiogenic blindness or amaurosis emboli are mainly responsible fugax Temporal arteritis Affects elderly individuals, and frequently leads to complete blindness; patients complain of headaches, and the ESR is usually raised Tsementzis, Differential Diagnosis in Neurology and Neurosurgery © 2000 Thieme All rights reserved. The examination re- veals impaired visual acuity (20/200), a cen- tral scotoma, and occa- sionally papilledema (when the inflamma- tion is just behind the nerve head) Differential diagnosis – Papilledema (due to the severe visual loss, since vi- sion remains normal in papilledema unless there is hemorrhage or exudate into the macula retinal area, which leads into rapid central visual loss – Optic chiasmal compression (central vision is served by the papillomacular bundle, which is more sensitive to external compression than the rest of the optic nerve fibers. The presence of optic atro- phy and bitemporal field defects are the clues to the diagnosis – Trauma (fracture of the anterior cranial fossa ex- tending into the optic foramen) – Amblyopia with papilledema (transient attacks as- sociated with raised intracranial pressure, e. Bilateral Sudden Visual Loss Cortical blindness Loss of vision with preservation of the pupillary light reflex and normal ophthalmoscopic examination Transient blindness Mild head trauma, migraine, hypoglycemia, hypoten- sion Tsementzis, Differential Diagnosis in Neurology and Neurosurgery © 2000 Thieme All rights reserved. Sudden and marked impairment of the basilar artery flow, usually in elderly individuals! Posttraumatic intracranial hypertension, leading to tentorial herniation and causing compression of the posterior cerebral arteries Hemorrhage E. Transient Monocular Blindness 103 Transient Monocular Blindness Embolic 3–5 minutes in duration; quadrantic, altitudinal, or total visual loss, corresponding in distribution of reti- nal arterioles; associated with contralateral hemiplegia with or without hemihypoesthesia. The most common type of embolus is cholesterol embolus, manifesting as a glistening, shiny, slightly irregular object with the narrowed retinal vessel, corresponding to a field de- fect, and in other retinal areas, since the cholesterol emboli are often multiple. Fibrin platelet emboli mani- fest as creamy white molding on the arterial tree, re- sembling an amorphous plug; they may coexist with cholesterol emboli.