By V. Tizgar. Minot State University--Bottineau. 2019.
Little or no movement of the reservoir bag suggests that the patient is mouth breathing 20mg vardenafil, or that there is a gross leak generic vardenafil 10 mg free shipping, for example buy vardenafil 20mg line, a poorly fitting nasal mask. Plane 1: moderate sedation and analgesia This plane is usually obtained with concentrations of 5-25% nitrous oxide (95-75% oxygen). As the patient is being encouraged to inhale the mixture of gases through the nose, it is necessary to reassure him or her that the sensations described by the clinician may not always be experienced. The patient may feel tingling in the fingers, toes, cheeks, tongue, back, head, or chest. There is a marked sense of relaxation, the pain threshold is raised, and there is a diminution of fear and anxiety. The patient will be obviously relaxed and will respond clearly and sensibly to questions and commands. Other senses, such as hearing, vision, touch, and proprioception, are impaired in addition to the sensation of pain being reduced. The peri-oral musculature, so often tensed involuntarily by the patient during treatment, is more easily retracted when the dental surgeon attempts to obtain good access for operative work. The absence of any side-effects makes this an extremely useful plane when working on moderately anxious patients. Plane 2: dissociation sedation and analgesia This plane is usually obtained with concentrations of 20-55% nitrous oxide (80-45% oxygen). As the patient enters this plane, psychological symptoms, described as dissociation or detachment from the environment, are experienced. It may also take the form of a euphoria similar to alcoholic intoxication (witness the laughing gas parties of the mid-nineteenth century). Apart from the overall appearance of relaxation, one of the few tangible physical signs is a reduction in the blink rate. At the deeper level of this plane of sedation the psychological effects become more pronounced. There is a noticeable tendency for the patient to dream, the dreams usually being of a pleasant nature. It is believed by many operators that the dreams experienced by the patient are to some extent conditioned by the ideas and thoughts introduced by the dental surgeon during the induction phase of sedation. The sedative effect is considerably pronounced, with both psychosedation and somatic sedation being present. The psychosedation takes the form of a relaxed demeanour, and a willingness on the part of the previously unwilling patient to allow treatment regarded as frightening or especially traumatic. The somatic sedation takes the form of physical relaxation, unresisting peri-oral musculature, and occasionally an arm or leg sliding off the side of the dental chair indicating profound relaxation. The analgesic effect is probably accentuated by the sedation and sense of detachment. The patient is still able to respond to questions and commands, although there may be a considerable mental effort involved in thinking out the answer. Paraesthesia may be more pronounced and cover a greater area of the body than in plane 1. The patient is nevertheless obviously conscious and can demonstrate this by keeping the mouth wide open to assist the dental surgeon during operative treatment. Plane 3: total analgesia This plane is usually obtained with concentrations of 50-70% nitrous oxide (50-30% oxygen). It has been claimed, that analgesia is so complete that extraction of teeth may be carried out in this plane. It is important to recognize that in a small number of patients as little as 50% nitrous oxide may bring about loss of consciousness. It is for this reason that dentists must exercise considerable caution if the concentration of gas coming from the machine rises above 40% nitrous oxide. It is for this reason that a mouth prop must never be used, for if a prop is used the open mouth sign would not function. If sedation is too deep and the patient shows signs of failing to co-operate, then the dentist should reduce the concentration of nitrous oxide by 10 or 15% for a couple of minutes. If it is considered necessary to lighten the sedation even more rapidly, the nasal hood should be removed and the patient allowed to breathe ambient air. This plane of total analgesia is regarded as a buffer zone between the clinically useful planes of moderate and dissociation sedation and analgesia, and the potentially hazardous plane of light anaesthesia. The major disadvantage (or minor if handled properly) is the inconvenience of the nasal hood restricting access to the upper incisor area if an apicectomy is required. This problem can be overcome by careful retraction of the upper lip and counterpressure from the thumb held on the bridge of the nose. Considerable care needs to be taken to discourage the patients from mouth breathing, to use rubber dam whenever possible, and ensure that full recovery is carried out with the nasal hood in place. This design of scavenger can be used on a normal relative analgesia machine without any specific modifications to the machine itself. All that is required is a change in the design of the nasal hood and the tubing leading from the machine to the hood. First, the expiratory and/or air entrainment valve on the nasal hood itself is removed and replaced with a simple blank because the use of this valve is obsolete. The efferent tube that leads away from the nasal mask is doubled in diameter to reduce resistance and connects to a specially devised exhaust pipe built into the wall or floor of the surgery. If considered essential, negative pressure can be applied at this connection to increase the efficiency of the scavenging (active scavenging). Key Points To reduce nitrous oxide pollution • use a scavenging system; • use a scavenging nasal hood (block air entrainment valves in older nasal hoods); • discourage mouth breathing (do not let the child talk); • use rubber dam. Unfortunately, the risk of unintended loss of consciousness is high with propofol because of the narrow therapeutic range of the drug that leads quickly to anaesthesia. A disposable tray should be prepared with the following: (1) a 5 ml syringe; (2) a venflon; (3) adhesive tape; (4) a green needle gauge 21; (5) isopropyl alcohol swab; (6) a single ampoule of the intravenous sedation drug; (7) an ampoule of flumazenil (for urgent reversal of benzodiazepine sedation); (8) a tourniquet. This usually entails a loading dose of 2 mg followed by further increments as appropriate. The technique requires the insertion of a venflon that is allowed to remain in situ until the treatment for that visit is complete. Nevertheless, there appears to be a group of older children, usually adolescents requiring dento-alveolar surgery, who are willing to allow the placement of a needle in the dorsum of the hand or the antecubital fossa for infusion of benzodiazepine drugs. Intravenous access The two most common sites of access are the antecubital fossa and the dorsum of the hand. In children especially, the antecubital fossa carries with it the danger of the needle causing damage to the vein and surrounding structures if the arm is bent during sedation. Note: a very anxious patient might be distressed by these procedures so they can be left until the patient is sedated.
Streptokinase is a nonenzyme protein that is isolated from streptococci; it binds to plasmin- ogen to catalyze the conversion of plasminogen to active plasmin generic vardenafil 20mg mastercard. Many individu- als have antistreptococcal antibodies because of prior exposure to the bacteria; this can reduce effectiveness and complicate treatment discount vardenafil 10mg overnight delivery. Although streptokinase is commonly used in Europe vardenafil 10 mg generic, it is no longer marketed in the United States. Urokinase is a protease originally isolated from urine; the drug is now prepared in recombi- nant form from cultured kidney cells. It is less antigenic than streptokinase and is indicated in patients sensitive to streptokinase. A patient is admitted to the hospital for gall- constant abdominal pain, nausea, and short- bladder surgery, and although the surgery is ness of breath. A young couple present to their primary (E) Folic acid care physician stating that they are trying to conceive. A man undergoing chemotherapy for lung future mom-to-be needs to be on any cancer complains of shortness of breath when supplements. Which of the following women develop iron deficiency anemia would be most appropriate for this patient? A 65-year-old diabetic man develops end- peripheral vision and dizziness that lasts for stage renal disease. A 53-year-old obese woman is brought into stored in the body the emergency room by her concerned husband (E) It participates in the mitochondrial reaction approximately 1 hour after complaining of that produces succinyl-CoA 186 Chapter 7 Drugs Used in Anemia and Disorders of Hemostasis 187 7. He states that since he does not have alcohol abuse presents to the urgent care medical insurance, he only comes to see a doc- clinic complaining of lightheadedness and tor when he experiences these ‘‘crises. His laboratory studies pain medication is the emergency physician indicate a low hemoglobin level. A 74-year-old woman who is undergoing (E) Folic acid chemotherapy for advanced lung cancer presents to the infusion center for her next 8. Before each treatment her white goes gastric bypass surgery to help her lose count, hemoglobin, and platelet counts are weight. Her surgeon reminds her that now she checked to make sure she is not experiencing will have to get a monthly injection of vitamin chemotherapy-related cytotoxicity. Her blood B12, since the part of her stomach responsible sample is run in the analyzer, and her platelet for production of intrinsic factor has been count is reported to be at a dangerously low removed. A 55-year-old woman undergoes an open (E) Neurologic deficits are not seen with this cholecystectomy. She is admitted for postopera- kind of anemia tive observation and started on subcutaneous heparin treatment to prevent formation of deep 9. A 31-year-old pregnant woman presents to venous thrombosis, a major risk factor for pul- her obstetrician for a routine visit. Which of the following is eral questions for her doctor, one of which has true regarding the mechanism of action of to do with the supplements that she was advised heparin? She stated she (A) Heparin increases activity of antithrombin leads a very busy lifestyle and sometimes forgets (B) Serine proteases of the clotting cascade are to take all the pills she is supposed to take. She deactivated wants to know the purpose of folic acid supple- (C) Heparin catalyzes clotting in vitro mentation in pregnancy. A 63-year-old man has a history of atrial fi- (C) It aids in bone growth of the maturing fetus brillation. To reduce his risk of a stroke, his phy- (D) It stimulates myelopoiesis of erythroid pro- sician had given him an anticoagulant genitor cells medication. This agent, while being of tremen- (E) It reduces blood viscosity during pregnancy dous benefit to this patient, comes with its asso- ciated risks, such as spontaneous hemorrhage. A 29-year-old African-American man To monitor the appropriateness of the current presents to the emergency department with a dosage of the medication, the patient comes in chief complaint of severe pain in his arms and frequently to have the laboratory check his pro- legs. Which medication must this knows that what he is experiencing is a sickle patient be taking? You are very excited, (D) Coumarin because you, in fact, had just reviewed your (E) Protamine pharmacology. A 75-year-old man is brought to the emer- (B) Coumarin gency department after being found on the floor (C) Clopidogrel of his room. His wife tells you that his medical (D) Alteplase history includes two prior strokes, for which he (E) Dextran is now taking a ‘‘small pill that works on plate- lets. After 6–7 days of parenteral feeding, vitamin K stores are depleted and clotting factor biosynthesis is impaired. Ticlopidine is an anticoagulant, and urokinase is a thrombolytic; both would be contraindicated in this circumstance. Digoxin is a cardiac glycoside that can improve contractility in impaired myocardium but would not be used in this circumstance. Prophylactic antiplatelet therapy should be instituted while the diagnosis is confirmed. While increased bleeding tendency, dietary deficiency, and malabsorption are all true causes of iron deficiency anemia, they are not the culprits during pregnancy. Iron storage is regulated at the level of absorption, and very little of it is lost from the body. Participation in the mitochondrial reaction that produces succinyl-CoA refers to the mechanism of action of one of the natural cobalamins, deoxyadenosylcobalamin. Sideroblastic anemia may develop in alcoholics and patients undergoing anti- tuberculin therapy. Vitamin B12 and folic acid are used for megaloblastic anemias caused by depletion of the vitamin. Loss of vitamin B12 is a very slow process, with hepatic stores being sufficient for up to 5 years. Folic acid supplementation has been shown to decrease the incidence of neu- ral tube defects. Increasing the oxygen-carrying capacity of the blood refers to a possible role of iron supplements. Stimulating myelopoiesis of ery- throid progenitor cells refers to the mechanism of action of erythropoietin. Finally, reduction of blood viscosity during pregnancy refers to pentoxifylline; however, this medication is not recom- mended during pregnancy. Hydroxyurea increases the production of fetal hemoglobin and has been shown to be effective in reducing painful episodes of sickle crisis. Acetaminophen is unlikely to be helpful in this patient’s situation, as this agent is useful for mild-to-moderate pain. Oprelvekin has been shown to reduce the need for platelet transfusions follow- ing myelosuppressive chemotherapy. Leucovorin is used in patients undergoing treatment with methotrexate, to prevent some of its side effects. Heparin releases lipoprotein lipase from vascular beds, which accelerates clearing of lipoproteins from plasma. The clotting factor is inactivated, which releases heparin and allows it to be recycled. Coumarin is commonly used in patients with atrial fibrillation for prevention of thromboembolic events, such as stroke.
Revised in 2001 following passage of Needlestick Safety & Prevention Act to include stronger requirements for employers to evaluate & adopt safer medical devices best 20 mg vardenafil. Universal precautions: All blood & certain body ﬂuids are to be handled as if known to be infectious for bloodborne pathogens buy vardenafil 20 mg mastercard. Engineering controls: Control measures that isolate or remove a hazard from workplace buy vardenafil 20 mg without prescription, e. Hepatitis B vaccine: Provided by employer within 10 days of assignment at no cost to employee. Sharps injury log: Must include description & location of incident, device involved. Must be securely closed, watertight, surrounded by absorbent material, & placed in secondary container. Secondary container Must be watertight, sealed, & placed in approved mailing container. Training Employees must be trained & retrained every 2–3 yr or when regulations change. Written for manufacturing industry, but courts expanded jurisdiction to clinical labs. Primary Requirements Written chemical hygiene plan outlining standard operating procedures for use, storage, exposure control, & disposal of hazardous chemicals. Concen- Can cause injury on inhala- trated acids & bases can generate large tion or contact. Mutagens & teratogens Benzene, lead, mercury, ra- Mutagens induce genetic Special precautions during pregnancy. Ignitables Acetone, alcohols, ether, Fire Flashpoint = lowest temp that produces xylene ignitable vapor. Perchloric acid may react explosively with organic compounds; separate from other acids. Hazard Identiﬁcation System continued Laboratory Operations Review 15 Red area = flammability Blue area = Yellow area = health reactivity White area = special dangers Safety diamond. Colored areas within the diamond indicate types of danger: red area (top) = ﬂammability; blue area (left) = health; yellow area (right) = reactivity; and white area (bottom) = special dangers. Separate Inorganic: hydrochloric, nitric, sulfuric from ﬂammable & combustible material, bases, & active Oxidizing: chromic, nitric, perchloric, sulfuric metals (e. Oxidizers Nitric acid, perchloric acid, sulfuric acid, acetic Separate from reducing agents (e. Heparin Green Prevents clotting by Many chemistries, os- Best anticoagulant for prevention of neutralizing thrombin motic fragility, plasma hemolysis. Sodium citrate Light blue Prevents clotting by Most coagulation tests Preserves labile clotting factors. Tube must binding Ca2+ be full for 9:1 blood-to-anticoagulant ratio or coag results falsely↑. To ensure proper ratio when drawing with butterﬂy, use discard tube to clear air from tubing. Sodium ﬂuoride Gray Inhibits glycolysis Glucose, lactic acid, Preserves glucose for 24 hr. Combined (not an anticoagulant) blood alcohol with K oxalate if anticoagulation needed. Coagulation Light blue Drawing before other anticoagulant & clot activator tubes avoids (citrate) contamination with additives that can aﬀect coag results. Serum Red, gold, speckled Drawing before green avoids contamination with sodium heparin (with/without clot (↑Na+) or lithium heparin (↑Li+). Drawing before 2 gray avoids contamination with sodium ﬂuoride/potassium oxalate (↓Ca2+,↑Na+,↑K+, interference with some enzyme assays). Drawing before gray avoids contamination with sodium ﬂuoride/potassium oxalate (↓Ca2+,↑Na+,↑K+). Lab may draw below heparin lock if heparin locks, cannulas nothing is being infused. Warming Cold agglutinins, cryoglobulins Use 37ºC heat block, heel warmer, or hold in hand. Protection from light Bilirubin, carotene, erythrocyte protoporphyrin, Wrap in aluminum foil. Inadequate mixing of anticoagulant tube Micro-clots, ﬁbrin, platelet clumping can lead to erroneous results. Radius (r) Distance in cm from center of rotation to bottom of tube when rotating. Polycarbonate Stronger than polypropylene & better temp tolerance, but chemical resistance not as good. Mechanical Micropipets Laboratory Operations Review 33 Types Air displacement Uses suction to aspirate & dispense sample through polypropylene tip. Calibration Verify accuracy & precision on receipt, after service or repair, & on regular schedule. Most accurate method for calibration is gravimetric method (weight of distilled water delivered). Secondary method is spectropho- tometric (absorbance of potassium dichromate orp-nitrophenol delivered). May be acceptable for some lab applications when higher purity chemicals aren’t available. Puriﬁcation systems use various combinations of distillation, deionization, reverse osmosis, & ﬁltration. Instrument feed water Used in automated analyzers for rinsing, dilutions, water baths. Water supplied by a method manufacturer Water provided by manufacturer for use in particular test system. Impurities that could contaminate washed labware or solutions in autoclave are removed. Commercially bottled, puriﬁed water Must meet speciﬁcations for intended use & be packaged to protect from degradation & contamination. Depth of focus Distance throughout which all parts of specimen are in focus simultaneously. Kohler illumination Method of focusing & centering light path & spreading light uniformly. Most commonly used are low power (10×), high power (40×), & oil immersion (50×or 100×). Parcentric Object in center of ﬁeld at 1 magniﬁcation will be in center of ﬁeld at other magniﬁcations Parfocal Object remains in focus from 1 magniﬁcation to another Planachromatic objective More expensive objective that corrects for curvature of ﬁeld. Objects appear Identiﬁcation of liveTreponema pallidum& white against black background. Fluorescent Direct & indirect ﬂuorescent antibody dyes absorb light of 1 wavelength & emit light of longer stains in microbiology & immunology wavelength. Interference contrast Brightﬁeld microscope with special slit aperture below con- Wet mounts denser, polarizer, & special amplitude ﬁlter (modulator) in back of each objective.
Agranulocytosis occurs more frequently with clozapine than with other agents buy cheap vardenafil 20 mg line, requiring routine blood tests effective vardenafil 10mg. The unique affinities of various antipsychotics result in their unique activities and their unique side effects purchase vardenafil 20 mg on line. Phenytoin and carbamazepine can be used in partial seizures or in tonic-clonic seizures. Gingival hyperplasia is a unique side effect of phenytoin, which can be partially avoided by meticulous oral hygiene. Aplastic anemia is a rare, but a potential complication of carbamaze- pine, ethosuximide. Ethosuximide has been associated with a severe form of erythema multiforme, the Steven-Johnson syndrome. Tiagabine is an anticonvulsant used in conjunction with drugs such as pheny- toin. Gabapentin is approved for the treatment of diabetic nephropathy, an unfortunate consequence in this patient’s presentation. Acetazolamide, sometimes used as a treat- ment for absence seizure control, is used in the treatment of glaucoma. Salicylate toxicity initially increases the medullary response to carbon dioxide, with resulting hyperventilation and respiratory alkalosis. Increases in lactic acid and ketone body formation result in a metabolic acidosis. Treatment includes correction of acid–base disturbances, replacement of electrolytes and fluids, cooling, alkalinization of urine, and forced diuresis. From the presented list, only methotrexate is known to be an antineoplastic agent. This medication has been used successfully in rheumatoid arthritis and other rheumato- logic conditions. Probenecid and sulfin- pyrazone reduce urate levels by preventing reabsorption of uric acid. Allopurinol is a xanthine oxidase inhibitor; it is also used for treatment of chronic gout. Cyclophosphamide has been successfully used for treatment of lupus nephri- tis; however, it does carry significant morbidity associated with its use. Deferoxamine is an iron-chelating agent and as such can be given in cases of iron supplement overdose. Diazepam and lorazepam are very effective at treating the vertigo associated with Meniere disease. Loop diuretics, such as furosemide, can precipitate vertigo secondary to volume depletion and resultant orthostatic hypotension. Both omeprazole and lansoprazole are proton inhibitors that would not increase the protective mucus and bicarbonate. Nizatidine is an H2-blocker that would also do nothing to increase the production of protective prostaglandins. Pepto Bismol, clarithromycin and amoxicillin, and omeprazole can be used for 7 days to eradicate Helicobacter pylori associated with peptic ulcer disease (metronidazole and tetracycline are additional choices for antibiotics). Regimens containing clarithromycin are used for cases of resistance to metronidazole. Psyllium and methylcellulose are bulk-forming agents good for chronic constipation. Salt-containing osmotic agents such as magnesium sulfate are good for acute evacuation of the bowels. Loperamide would be a good choice in this patient as it effectively controls diarrhea. Both codeine and diphenoxylate are opioids with abuse potential, especially in patients with abusive histories. Diphenoxylate is available in combination with atropine to reduce the potential for abuse. Anticholinergic agents such as propantheline prevent cramping but have little effect on diarrhea. Octreotide is used for diarrhea secondary to increased release of gastrointesti- nal hormones. Bismuth subsalicylate and loperamide can be used in the treatment of uncompli- cated diarrhea. Infliximab is a monoclonal antibody approved for the treatment of refractory Crohn disease when mesalamine or steroids fail. Opium tincture and diphenoxylate are opioid preparations for uncomplicated diarrhea. They usually occur at elevated blood levels, generally accepted as greater than 20 lg/dL. A disulfiram-like reaction may be seen in non-insulin-dependent diabetics treated with chlorpropamide, an oral hypoglycemic, when used in combination with alcohol. Elderly patients with subclinical hypothyroidism are at risk for arrhythmias, angina, or myocardial infarction if they have underlying cardiovascular disease when they begin treatment with thyroid hormones such as levothyroxine. These potential adverse effects occur because of increased cardiovascular workload as well as the direct effect of thyroid hormone on the heart. Prednisone, a steroid commonly used to treat exacerbations of lupus erythem- atosus, can cause peptic ulcer disease due to the inhibition of the prostaglandins that normally protect the mucosa. Conjugation is the principal mechanism for the acquisition of antibiotic resist- ance among enterobacteria and involves the transfer of resistance transfer factors on plasmids through sex pili. The other mechanisms for gene transfer, including random mutation, transfor- mation, transduction, and transposition are not as common among these organisms. It is an inhibitor of renal dehydropep- tidase, which normally would degrade imipenem. Probenecid increases penicillin concentra- tions by blocking their excretion by the kidney. Both clavulanic acid and sulbactam are penicillinase inhibitors used to increase the spectrum against penicillinase-producing species. Cefazolin, a first-generation cephalosporin, is often used for surgical prophy- laxis because it has activity against most gram-positive and some gram-negative organisms. Second-generation agents (cefoxitin) and third-generation agents (ceftriaxone) are not used because they have less gram-positive coverage. Piperacillin, cefoxitin, and imipenem all have some overlap in penicillin-allergic patients. Although ciprofloxacin is good in nonpregnant patients, it is absolutely contraindicated in pregnancy. Cefamandole, a cephalosporin, is known to precipitate a disulfiram-like reac- tion. Bone marrow suppression results in pancytopenia in treated patients, which in rare cases can lead to aplastic anemia. Macrolides such as azithromycin or clarithromycin are the agents of choice for the treatment of mycoplasmal diseases.
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