By Y. Tom. Walden University. 2018.
I call the diseases caused by fluke stages in inappropriate locations Fluke Disease; it is discussed in more detail later (page 249) discount 250mg diamox with visa. Pollutants can invade your body via the air you breath cheap 250mg diamox otc, the foods and beverages you eat diamox 250mg discount, and the products you put on your skin buy diamox 250 mg mastercard. The one who did not assumes the cream is not harmful to them…that they are like a bank vault, impreg- nable to that product. A better assumption is that the face cream is somewhat toxic, as evidenced by the rash that can develop, and they escaped the rash only because they had a stronger im- mune system. The immune system is like money, paid out of the bank vault, for every toxic invasion. Most other solvents dissolve fats and are life threatening, because fats form the membrane wall around each of our cells, especially our nerve cells. Metal Pollution Biochemists know that a mineral in raw element form always inhibits the enzyme using that mineral. Inorganic copper, like you would get from a copper bottomed kettle or copper plumbing, is 3 carcinogenic. We put metal jewelry on our skin, eat bread baked in metal pans, and drink water from metal plumbing. Mercury amalgam fillings, despite the assurances of the American Dental Association, are not safe. And sometimes the mercury is polluted with thallium, even more toxic than mercury! Gold and silver seem to have fewer harmful effects, but no one should have any pure metal in or on their body. Other prevalent toxic metals include lead and cadmium from soldered and galvanized plumbing, nickel and chromium from dentalware and cosmetics, and aluminum from food and drink cans, and cooking pots. From Carcinogenicity and Metal Ions, volume 10, page 61, of a series called Metal Ions in Biological Systems, edited by Helmut Sigel, 1980. One small moldy fruit or vegetable can pol- lute a huge batch of juice, jam or other product. Although molds are alive, and can be killed by zapping, mycotoxins are not, and must be detoxified by your liver. But because mycotoxins are so extremely poisonous, a tiny amount can incapacitate a part of the liver for days! For that reason I am always cautioning people to eat only perfect citrus fruit, and never drink commercial fruit juice. Of the thousands of oranges that go into the batch of orange juice you drink, one is sure to be moldy, and that is all it takes to give your liver a setback. It also helps get rid of aflatoxin before it is consumed, right in the food container. So keep a plastic shaker of vitamin C powder handy and use it like salt on all your food. Physical Toxins Breathing in dust is quite bad for you so your body rejects it by sneezing, coughing, spitting up and out. But because it is sharp it gets caught in your tissue, then works its way deeper and deeper. We are unaware that it fills our homes when fiberglass insulation is left imperfectly sealed off. Any hole made through the ceiling or wall, even if covered with cloth, lets swarms of broken glass bits into the house air. Of course, fiberglass should never be used in home construction, draperies, or around water heaters. The best advice is to have it all removed while you are away and then vacuum and dust. Chronic exposure from a single small hole in the ceiling does a lot of harm, leading to cyst formation. And that cyst is a perfect place for parasites and bacteria to settle and multiply. Asbestos is another tiny bit, sharp as glass, that moves through your body like a swordfish, impaling your cells until it, too, gets routed into a cyst. We have been led to believe that we no longer have asbestos in our homes because we have outlawed the fireproofing mate- rials it was used in. While that may be true, the source I find most often is all too prevalent: the clothes dryer belt. As it gets hot the belt releases a blast of asbestos particles that are forced through the seams of your dryer, and also openings in your exhaust hose, by the high pressure formed inside. By the time your air conditioner or refrigerator needs recharging, you have been exposed for a long time. Our diligent scientists have studied the mechanism of arsenic poisoning in great detail. Then why are we allowed to put it on our lawns to be carried into our carpets via shoes? As a result, foam fur- niture, pillows and mattresses give off formaldehyde for about two years after manufacturing. If you sleep with your nose buried in a new foam pillow all night, you are risking major lung problems. And what if you found that although many people had them, those who were sick with a cold always had at least one of them. Would you ask whether a sudden buildup of mycotoxins is what really lets colds develop? What if you always found every mysteriously ill person had some unsuspected parasite or pollutant? They forced me to alter my entire outlook on what really causes some of our “incurable”, mysterious diseases. This multicausal concept is what made the study of medicine so difficult that only a few could undertake it. But these diagnoses are based on a description of what is happening at a particular place in your body. This is like calling a mosquito bite behind the ears by one name and a mosquito bite behind the knee by another name. If you never see the true cause, a mosquito at work, this system could be excused as somewhat sensible. And you can find them yourself by building the electronic diagnostic circuit (page 457)! Once you have seen a mosquito at work on your body you no longer need to go to the doctor for a red, itchy bump. Once you have seen how common house dust is implicated in the common cold you get rid of the house dust. Once you have seen the mold in your food facilitate the cold virus you throw out that moldy food. The electronic resonance method described in this book will let you see all these things for yourself.
This agent has been quite extensively used in Europe from the time of the Middle Ages buy 250 mg diamox with amex. One of the old writers—Dragendorff—says the bark is given in malarial fevers cheap diamox 250mg with visa, in dropsy purchase diamox 250 mg otc, gout generic diamox 250 mg on-line, disease of the lungs; also in abscesses, and in skin diseases and itch, and where there is excessive sweating of the feet. Isenburg of Hamburg, Germany: The bark contains betulin, a resinous substance, and betulalbin. The bark of the black variety contains glucosides, gaultherin, and an essential oil. Winternitz and Jenicke both recommend the remedy for its diuretic effect and for its influence in dissolving kidney stones. Winternitz made an infusion of the dried leaves in the preparation of one part to six or eight parts of water by weight. The urine was concentrated, sometimes bloody, contained pus cells, and uric acid in large quantities with three and one-half per cent of albumin. There has been passed from time to time with the water tiny pieces of stone from the kidney. We have had reports from a number of writers in this country concerning the action of this remedy in a similar manner, and all confirm the observations made by the German writers. Synonyms—White Agaric (Agaricus Albus), Larch Agaric, Purging Agaric, Fungus Agaric, Spunk. Specific Symptomatology—Chilliness at regular intervals, followed by marked fever. Alternate chills and flushes of heat, with severe aching in the back, colliquative sweats, night sweats of phthisis. It is especially useful in those localities where malaria and the results of malaria prevail. The symptoms are languor, dullness, and general malaise, long continued, with the usual results, such as disordered digestion, lack of appetite, heavily coated tongue, pale mucous membranes. Usually there is a bitter taste in the mouth, often persistent, with constipation, and a dull, persistent headache. The intermission, or remission, may be irregular, not only in time, but in amount. The broncho-pulmonary secretion of incipient phthisis, or the night sweats of the protracted cases, are benefited by this remedy. It also controls the rapid circulation and seems to exercise a favorable influence over the hectic fever. It will arrest the flow of milk, in the nursing woman, and will correct in many cases the tendency to passive hemorrhages. Some claim that it will check arterial hemorrhage, making the application of a ligature unnecessary. Those who are constantly under the influence of alcohol, trembling, weak with cold skin, he gives one or two drops of the specific medicine every two hours. Ellingwood’s American Materia Medica, Therapeutics and Pharmacognosy - Page 81 Agaricus acts upon the nerves of the skin, controlling involuntary twitching of the face and eyes. While agaracin, or agaric acid, is most commonly used in consumption, and the observations have been made from its influence, it is doubtful if it is superior to the specific boletus if the latter remedy is given in proper doses, and persisted in. An infusion of half an ounce in a pint of water should be made and drunk on rising in the morning. The patient should take but little food during the day, and if the bowels do not move freely, a physic should be taken at night. An extractive is obtained from the plant, known as Koosin, which is given in doses of twenty grains. Physiological Action—In large doses bryonia is an active hydragogue cathartic and sometimes causes inflammation of the stomach and bowels. Ellingwood’s American Materia Medica, Therapeutics and Pharmacognosy - Page 82 In poisonous doses it causes a fall of temperature, dizziness, delirium, weak pulse, cold perspiration, dilated pupils and other evidences of a depressing action on the nervous system. The recent root is highly irritant when locally applied, and capable of producing, vesication. The results from laboratory observations of this agent do not to any degree suggest its clinical adaptions. Specific Symptomatology—The following symptoms demand the use of bryonia: Distress or pain in acute inflammatory disease, which is aggravated by movement increased by pressure; elevated temperature, with hard, frequent, vibratile pulse; the muscular structures sore and tender, as if bruised; acute lung or bronchial disorders, with no expectoration, dry cough, short and harsh, or hacking, with soreness increased by coughing; flushed right cheek frontal pain extending to the basilar region; irritating cough. Again: Sharp, cutting, lancinating or tearing pain from serous inflammation; increased muscular tension, and tenderness on pressure, aggravated by motion; headache on the right side; inflamed lung structure, with pain and soreness relieved by lying on the inflamed side, usually with a bright spot on one cheek. With this latter indication its influence is often enhanced by alternation with small doses of belladonna. Bryonia promotes the elimination of heat, and like aconite, it opposes the dryness of the mucous membranes induced by inflammation which suspends secretion. It is thus valuable in enteritis, in the inflammation of the glandular organs, and in pulmonary and bronchial inflammations, always looking for its precise indications—tenderness on pressure, tiny shooting pains, or pain increased by motion. The absorption of inflammatory products, either of a serous or sanguineous character, is greatly facilitated by this remedy. Its influence upon inflammatory processes and upon the results of inflammation is even more positive in certain cases than aconite. Therapy—Bryonia is a remedy of great value in the treatment of all acute Ellingwood’s American Materia Medica, Therapeutics and Pharmacognosy - Page 83 inflammations of the thoracic viscera or of the pleura. Occasionally, though, more rapid results will be accomplished by alternating it with aconite or with asclepias tuberosa. One physician, in two cases of pleurisy where there was at least a pint of serum in the pleural sac of each, gave bryonia alone, and persistently using it for a reasonable time, the entire quantity in both cases was absorbed, and the patient made an excellent recovery. In bronchitis, with short, quick cough, with quick, sharp pains, especially if the sputum be bloody or frothy, bryonia acts directly. It should be given in small doses, at short intervals, and should be persisted in. It will subdue the pain and the cough promptly and exercise as marked an effect on the fever as any special sedative known. If used in combination with other specific remedies, abatement of the symptoms will be even more rapid in these cases. Although opposed to complex medication, the author has used the following combination in these conditions in infants and children with the most happy results. In severe cases in small children, or during severe paroxysms, it is very desirable to give a yet smaller dose and alternate the remedies every twenty or thirty minutes: Rx— Tinct. Half of a teaspoonful every hour, alternated with the following prescription every half hour: Rx— Tinct. Half teaspoonful every hour, alternated with the above as stated, every half hour. I have found in many cases the precise indications for the use of this remedy, and in one Ellingwood’s American Materia Medica, Therapeutics and Pharmacognosy - Page 84 exceedingly bad case, I got excellent results, indeed, but I combined it with Mag. Henderson specifies a form of neuralgia of the face, usually on the right side caused by cold or from a draft with dull pain and stiffness or tenderness of the muscles, especially if there should be a sharp catch under the right shoulder or in the right side increased by inspiration as immediately relieved by a combination of bryonia and sticta, ten drops of each in four ounces of water, a teaspoonful every half hour. Bryonia controls the temperature and the fever processes, when the exact indications are present, as positively as any of the other known special sedatives.
Constriction of veins by sympathetic stimulation increases preload and may be an important factor in the control of cardiac output order 250mg diamox otc. In steady-state situations purchase diamox 250 mg overnight delivery, it is easy to imagine that the heart acts in a machine-like fashion diamox 250mg line, ejecting exactly the same quantity of blood in systole as enters in diastole diamox 250mg cheap. Different steady states can be compared and the work of the heart as a pump or its O2 consumption can be measured. It was recognized very early that the heart could adapt to changes in filling (venous return) by changing its performance as a pump. This was first shown in the isolated frog heart by Otto Frank at the turn of the century (Fig. In the experiment pictured, the heart was filled to different diastolic pressures and then allowed to contract isovolumically (i. Starling in England elaborated upon these studies in mammals and showed that changing right atrial filling led to elevation in stroke volume (ventricular end- diastolic volume minus end-systolic volume) and increased aortic pressures. In other words cardiac output or cardiac work (volume x pressure) was a function of filling pressure. He expanded our understanding by demonstrating that a given curve corresponds to a given level of contractility (inotropism). Interventions which increased contractility, such as the administration of epinephrine or Ca++ would allow the experimental heart preparation to increase its work for a given filling pressure. Conversely, negative inotropic influences such as sympathetic blockade would reduce cardiac work below control levels for a given filling pressure. Although this may seem obvious, it has raised some interesting questions and provided some new explanations for physiological observations. For example, during exercise with its attendant increase in cardiac output, was cardiac work in the normal heart increased due to increase in filling pressure? Or was filling pressure maintained constant by shifting cardiac function to a more positively inotropic curve due to sympathetic stimulation of the heart by locally released norepinephrine? In the case of heart failure, Starling demonstrated that as filling pressure rose to extremely high levels, cardiac performance initially increased, reached a plateau and then eventually declined ("The descending limb of the Starling Curve"). Was this the hemodynamic mechanism of heart failure or was a sustained low cardiac output due to depression of the normal curve to a lower inotropic state without being on a "descending limb"? Sonnenblick, Braunwald, Parmley and others reinvestigated the question of myocardial performance and contractility. Although the different Starling-Sarnoff curves defined different degrees of contractility, the work of the heart was measured exclusively as external work: systolic pressure x stroke volume. With measurement of work during ejection alone, Sarnoff had been measuring only isotonic work, whereas the heart was doing isometric and isotonic work. However, with reference to the Starling curves, the point is that since the work of Sarnoff, cardiac performance was seen as a function of filling pressure. Since reexamination of the heart as a muscle, it is clear that the change in myofibril length by preload is the variable which correlates best with subsequent stroke work. Since fiber length and filling pressure do not vary linearly, measurement of one cannot entirely substitute for the other. Thus a given ventricle, filled to a given end-diastolic pressure and volume would produce some specified stroke work with each beat. If, by some pathologic process, the ventricle would become stiffer during diastole (i. Measurement of Starling curves for the right heart and left heart differ (see Figs. Since both ventricles pump the same volume output, the stroke work differences are due to lower arterial pressure in the pulmonary artery than in the aorta. After all, in the human the thickness of the ventricular wall will be appropriate to the work (esp. Since the left ventricular peak systolic pressure (120 mm Hg) is 5- 6x higher than right ventricular peak systolic pressure (20 mm Hg), the left ventricular wall (10-12 mm) is 5-6x thicker than the right ventricular wall (1-2 mm). Similarly, the thicker wall will be less compliant, so that filling pressures for the left ventricle (5-12 mm Hg) are 5-10 x higher than filling pressures for the right ventricle (1- 2 mm hg) in the normally functioning heart. Although volume measurement would permit better correlation with fiber length, it is commoner to measure pressures in clinical situations. Reasons include the fact that it is easier to measure pressure (fluid-filled catheters are left in the atria or pulmonary artery) than volume; measurements are usually made over relatively short periods of time (minutes-days) and as a rule no important changes in compliance or heart size occur during such short times and compliance is difficult to measure precisely. For the right side of the heart clinical measurements usually utilize right atrial pressures, since these are in equilibrium with right ventricular end-diastolic pressures. For the left ventricle, pulmonary artery diastolic (sometimes pulmonary capillary, or "wedge") pressures are used. These approximate pulmonary venous pressures which are, in turn, in equilibrium with mean left atrial, and therefore, left ventricular pressures. For any stable compliance (or stiffness) a reduction in filling pressure would reflect a decrease in filling volume. A very high filling pressure might signal hypervolemia and the need for addition of an inotropic drug (e. Repeated measurements of cardiac output by indicator-dilution techniques may be made throughout such a series of pressure measurements and medical interventions. Peripheral resistance can then be calculated (Peripheral Resistance = Mean Arterial Pressure/Cardiac Output) and it, too, can be modified to maintain output at optimum levels. Some examples of different situations may help to clarify the changes in the Starling curves: Starling Curve and Venous Return - Jim Wong, M. Heart failure (-) inotropic* •* Means that this variable is the “initial” cause of the altered physiology. To understand the bases of measurement of intracardiac pressures, their significance and their normal range. The net volume of blood propelled from the heart in one beat is denoted the stroke volume. Even though the actual flow is pulsatile with instantaneous flow rate changing rapidly with time, constant demand on the heart to pump blood leads to a constant average flow rate, the cardiac output, which remains stable. If blood flowed in a simple tube and in discrete mass elements, one could flag one or more elements then watch the flag move to compute the flow rate. The Fick method follows directly from a statement of conservation of mass, assuming the subject remains in a constant physiological state. To obtain accurately measured cardiac output, the oxygen concentration in the blood entering and leaving the lungs as well as the cardiac output itself must remain constant during the period of measurement. Under these conditions the mass flow rate of oxygen away from the lungs equals the rate at which it is being carried in by - venous blood plus the rate of absorption from the air in the alveoli (Fig. In addition to requiring that the patient be in physiological steady state (especially constant respiratory activity and cardiac output), the indicator substance (generally oxygen) must be thoroughly mixed with the blood to truly represent the average concentration at each sampling point. Only passing through the heart assures adequate mixing; therefore, the Fick method requires obtaining blood samples in the heart or an artery beyond its mixing chambers. Typically, one takes blood samples to measure for oxygen saturation from any systemic artery (all arterial blood has the same oxygen concentration as the aorta) and from the pulmonary artery (equivalent to mixed venous blood). Furthermore, since the actual flow is highly pulsatile, the sample should be taken slowly, over 5-10 seconds, to insure measuring the average oxygen concentration (averaged over time, i. Having found Ci , Co , and O, one can use the Fick formula to compute cardiac output, F.
This arene oxide intermediate has been implicated as the source of various toxicities and teratogenicity associated with the use of phenytoin (19) discount diamox 250mg line. This suicide inhibition leads to disproportionate and dramatic increases in serum concentration with relatively small changes in dosing rate (12) discount 250mg diamox with visa. In most patients diamox 250mg overnight delivery, the usual therapeutic range exceeds the concentration at which metabolism is half-max- imal cheap diamox 250mg fast delivery, which causes phenytoin to exhibit a nonlinear profile in the majority of patients. A variety of situations such as concurrent illness, medications, pregnancy, age, or gene- tics may influence the maximal rate of metabolism and thus may alter the pharmacoki- netic profile of phenytoin in a given patient (20). At high serum concentrations (greater than 20 µg/mL) many patients exhibit lateral gaze nystagmus. Other adverse effects known to occur at excessive plasma con- centrations include ataxia, mental-status changes, and coma. Further, phenytoin has the ability to precipitate seizures or status epilepticus at extreme concentrations. Chronic adverse effects include gingival hyperplasia, which can occur in up to 50% of patients receiving long-term therapy. Other long-term effects include hirsutism, acne, coarsening of facial features, vitamin D deficiency, osteomalacia, folic acid defi- ciency (with resultant macrocytosis), hypothyroidism, and peripheral neuropathy. In addition, some patients exhibit cross-sensitiv- ity to other compounds with similar chemical structures such as barbiturates, succin- imides, and oxazolidinediones. Because of the risk of myelosuppression, the use of phenytoin in immunosup- pressed patients or patients with blood dyscrasias may increase the risk of infection or exacerbation of the hematologic abnormality. The metabolism of phenytoin may be impaired in patients with active liver dis- ease or active alcoholism with subsequent toxic effects associated with elevated serum concentrations (6,12,23). Drug Interactions Phenytoin is involved in many drug interactions (Tables 2 and 3). These interac- tions are well characterized and phenytoin may be the target or cause of interactions. Pharmacokinetic drug interactions affecting absorption, metabolism, or excretion have the potential to either increase or decrease the plasma concentration of phenytoin. Though food may slightly alter the rate of absorption of phenytoin, it is well recog- nized that enteral feedings can dramatically decrease the bioavailability of phenytoin suspension when administered via a feeding tube (24). Although phenytoin is highly protein bound, protein-binding interactions are gen- erally of minimal significance. This is followed by an increase in the clearance of phe- nytoin, a decrease in total phenytoin concentration, and subsequent reestablishment of baseline free phenytoin concentration (17). It is important that clinicians understand the mechanism of this interaction and do not react to decreases in total concentration without considering the possibility that free concentrations remain therapeutic. Replacement of folic acid effectively increases the clearance of phenytoin and thereby decreases pheny- toin concentrations. Supplementation of folic acid, alone or as a vitamin, has the poten- tial to decrease plasma phenytoin concentrations and subsequently decrease seizure control (25). T a b l e 3 I n t e r a c t i o n s w i t h O t h e r D r u g s * A E D A l t e r e d b y R e s u l t a A l t e r s R e s u l t a P h e n y t o i n A n t a c i d s D e c r. This lipophilicity strongly influences drug transport across biological membranes. This change in struc- ture alters the solubility of the compound and renders it only slightly soluble in chloro- form, dichloromethane, acetone, and methanol whereas it is practically insoluble in water ethanol and ether (27). This results in a net decrease in high-frequency repetitive firing of action potentials. These effects are evident and selective at serum concentrations within the therapeutic range (28). The 10,11 epoxycarbamazepine metabolite also con- tributes a similar therapeutic effect (29). The pharmacologic effect of oxcarbazepine is due to a principal metabolite, 10- hydroxy-oxcarbazepine (27). The mechanism of action is similar to that of carbamaze- pine but may also include increased potassium conduction and modulation of high- voltage calcium channels (30,31). The time to maximal serum concentration (tmax) is 8 or more h for tablets but 3–5 h for the suspension (33). That means that the full effects of a given oral dose of carbamazepine tablets may not be recognized until 8 or more h after the dose has been ingested, whereas a similar dose of the suspension reaches maximal concentration in just 3–5 h and may influence the interpretation of serum concentration data. In addition to delayed absorption of car- bamazepine from tablets, it has also been recognized that tablet formulations can be adversely affected by humidity and moisture content, thus further delaying or decreas- ing absorption (34). Approx- imately 35% of an oral dose is absorbed in zero-order fashion (no effect of dose on absorption) whereas the remainder of the dose is absorbed according to a first-order kine- tics. At doses greater than 20 mg/kg, an inverse relationship between dose and absorp- tion begins to occur (35). Consistent with its lower lipid solubility, 10,11 epoxycarbamazepine has a lower apparent volume of distribution and increased fraction unbound of 48 to 53% (39). To date, no accepted therapeutic range for the use of oxcarbazepine in treating epilepsy has been established (41). Clinical trials in patients treated for neurologic pain have reported serum 10-hydroxy-carbazepine concentrations between 50 and 100 µg/mL (42). As the autoinduction progresses, changes in daily dose are required to main- tain adequate plasma concentrations. These effects are typically dose related and may resolve with continued administration only to recur with significant increases in plasma concentration (9). Though somewhat common, there appears to be no association between the presence of leuko- penia and an increased incidence of infection. Hypersensitivity manifests most commonly as the development of an eczema- tous rash, which can progress in some patients to Stevens-Johnson syndrome (46). Dilutional hyponatremia and the syndrome of inappropriate antidiuretic hormone have been reported. The incidence of this phenomenon may increase with the age of the patient and appears somewhat dose related although low-dose therapy does not preclude the development of hyponatremia (47). As a tertiary amine, lamotrigine is only very slightly soluble in water, and slightly solu- ble in 0. Further, this action appears greater during repeti- tive activation, such as may occur during an epileptic seizure (double check that). Plasma concentrations peak 1–3 h after oral administra- tion and absorption appears to be linearly related to dose up to approximately 700 mg. Food does not alter the absorption of lamotrigine and systemic absorption can occur with rectal administration although to a more limited extent than with oral dosing (50). Although lamotrigine serum concentrations can be determined, no therapeutic range has been established for this drug and it is advised that treatment decisions be guided by thera- peutic response without concern for serum concentration (51). Metabolism can occur at either heterocyclic nitro- gen atom to form one of two glucuronide conjugates. Though some evidence suggests that lamotrigine may undergo autoinduction, the relatively slow onset of autoinduction and the slow, tapered dosing schedule make this autoinduction clinically insignificant. Less than 10% of an administered dose is renally eliminated as unchanged drug (51). Though sev- eral types of rash have been reported, the most common is a generalized erythematous morbilliform rash that is typically mild to moderate in severity.
If initial spirometry indicates severe obstruction purchase 250 mg diamox, an intra- venous bolus of 125 mg methylprednisolone should be considered purchase diamox 250mg without a prescription. It has been recommended that corticosteroids should be part of the initial therapy for women with severe diamox 250 mg online, acute asthma (Cunningham cheap diamox 250mg visa, 1994; National Heart, Lung and Blood Institute, 1991). After two or three doses of epinephrine or inhaled beta-agonists, if the wheezing is not corrected, then intravenous aminophylline may be indicated. Dosing should be based on theophylline levels, if the patient has been receiving oral theophylline (it should be noted that theophylline requirements decrease as pregnancy advances; see Table 5. The patient should be admitted to the hospital if she demonstrates a poor spirometric response to therapy, has no symptom improvement, or has pneumonia or pneumothorax. Endotracheal intubation and mechanical ventilation should be considered when signs of respiratory failure present. Patients who respond quickly to such therapy should be discharged on an intensified reg- imen. A tapering schedule of oral corticosteroids should be given if intravenous steroids were used. Close follow-up should be arranged to reassess their clinical condition and possible adjustments in medication. Opiates, sedatives, and tranquilizers are contraindicated in asthmatics because they cause alveolar ventilatory depression, and are associated with respiratory arrest imme- diately after use (Table 5. Beta-adrenergic blockers and parasympathetic agents should also be avoided in asthmatics because they can cause bronchospasm. Chronic asthma Chronic asthma patients need additional steroid therapy for coverage during the stress of labor if they have received oral steroid therapy for more than 2 weeks within the pre- vious year to prevent adrenal crisis. Corticosteroids should be given in cases of severe or mild asthma with wheezing that is unresponsive to bronchodilators. Beclomethasone dipropionate is effective and safe when prolonged steroid use is necessary. Beta-agonist by inhalation every 3–4 h as needed is used for outpatient management of chronic asthma, along with inhalation steroids such as beclomethasone (Cunningham, 1994). Cromolyn sodium can be given chronically by inhalation, and is fairly effective in improving the symptoms of an asthmatic. An added benefit with cromolyn use is a decreased requirement for other antiasthma agents. Cromolyn therapy is best begun during remissions because it requires several days to reach an effective dosing regimen. Medications that cause bronchospasm or depress alveolar ventilation should be avoided in the pregnant woman with asthma (Table 5. Effect of bronchial asthma on the course of pregnancy, labour and perinatal outcome. Many surgeons are reluctant to perform operative procedures on women known to be pregnant, although emergency procedures are sometimes necessary. In addition, elective or indicated procedures may be carried out on women with an unrecognized pregnancy. General principles that the clinician should be aware of when surgery is anticipated in a pregnant woman are based on physiologic differences between the pregnant and non- pregnant state (Box 6. Virtually all anesthetic agents and 98 percent of medications cross the pla- centa, exposing the fetus to medically significant levels. Even a minimal degree of hypotension and hypoxia is to be avoided because this may result in placental hypoperfusion and fetal hypoxemia. Pregnant women being prepared for surgery should be placed on their left side, adequately hydrated, and preoxygenated prior to induction of anesthesia. Pharmacokinetics of anesthetic agents have been reported for only pancuronium, and its disposition was a pregnancy-associated decreased half-life, and this was probably due to significantly increased clearance (Little, 1999). Increased blood volume is caused by a plasma volume increase of approximately 1000 cc and a 300–500 cc increase in red cells. This usually results in lower hematocrit compared to the nonpregnant woman, and is commonly known as physiologic anemia of pregnancy. Accordingly, the glomerular filtration rate increases (as measured by the endogenous creatinine clear- ance) because of increased blood volume. Serum creatinine and blood urea nitrogen decrease because of dilution by increased plasma volume. Other changes in the renal sys- tem include dilatation of the ureters and a relative stasis of urine, resulting in a ‘relative’ hydronephrosis. The relative hydronephrosis is frequently more pronounced on the right than on the left side. Other cardiopulmonary changes that occur during pregnancy include a slight increase in heart rate, and decreased systolic and diastolic blood pressures in the second trimester. Respiratory rate increases slightly during pregnancy with a decrease in physiologic ‘dead space’ as pregnancy pro- gresses. Tidal volume is increased during pregnancy, but minute ventilation and compli- ance do not change during pregnancy. Gastrointestinal system changes with pregnancy affect pregnant women that require anesthesia and/or surgery. The risk for aspiration pneumonitis in surgery on the gravid patient is increased because of pregnancy-associated decreases in intestinal motility and gastric emptying. This has implications for anesthesia dose man- agement of the pregnant patient; lower doses than in the nongravid patient may achieve the desired anesthetic effect. Serum levels as high as 400 mg percent are not unusual during the third trimester and cause increased red cell sedimentation rate in pregnant women. Hematocrit is decreased during pregnancy accompanied by a relative leukocytosis (white blood cell count greater than or equal to 10 000–12 000 or even higher during labor). Several hema- tologic measures are unchanged during pregnancy: for example, the relative percent of immature forms (i. Whole blood clotting time, prothrombin time, and partial thromboplastin time remain in normal ranges during pregnancy. Surgery should be performed without delay when it is indicated for life-threatening maternal conditions. Indicated laboratory tests and radiologic procedures should be per- formed without hesitation to properly guide life-saving surgical procedures. Anesthetic adjuncts, or other ‘nonanesthetic’ drugs and medications during the pre-, intra-, and post-operative peri- ods may also adversely affect the fetus. Regional techniques (spinal and epidural procedures, paracervical and pudendal blocks) result in physiologically important fetal exposure to clinically significant anesthetic levels. Anesthetic potency is related to protein-bound fraction, and the amount of binding determines the duration of action. Highly protein bound anesthet- ics are lipid soluble and readily cross the placenta (Morishima et al.
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