By F. Felipe. Lasell College. 2018.
This repair enhances glenohumeral stability by enhanc- ing the limited joint volume mechanism buy zyrtec 10 mg fast delivery allergy job market. Therefore multidirectional instability should be distinguished from multidirec- tional hyperlaxity and should be considered into a classification of shoulder instability discount zyrtec 10 mg with visa allergy forecast fresno ca. This differentiation of laxity and instability lead to the following classification: 1) Chronic locked dislocation 2) Unidirectional instability without hyperlaxity 62 7 Classifications of instability 3) Unidirectional instability with hyperlaxity 4) Multidirectional instability without hyperlaxity 5) Multidirectional instability with multidirectional hyperlaxity 6) Uni- or multidirectional voluntary instability This simple form of the classification has been helpful to determine diag- nostic and therapeutic strategies and to establish a basis of communica- tion with other orthopaedists. Description of static instabilities and recog- nition of osseous lesions to this classification may be an additional aid. A basis for this classification is that hyperlaxity (either generalized or of the shoulder) is an individual trait and not pathologic. However, hyper- laxity may be a factor of risk for having shoulder problems develop. If treatment becomes neces- sary, the consequences are entirely different from those imposed by a diagnosis of dynamic instability. In addition, these static instabilities currently are difficult to treat successfully. Static instabilities can co- exist with dynamic instabilities (recurrent anterior instability in a massive cuff tear with superior humeral migration) and then require a decision as to which instability has priority in treatment. Seven millimetres is currently the value used to define static superior subluxation. The cause of cranial migration of the humeral head seems to be insufficiency of the infraspinatus in the presence of a supraspinatus tear. Isolated supraspinatus, isolated infraspinatus, or combination tears of the supraspinatus and sub- scapularis tendons do not cause static superior instability. In ad- dition, such static superior subluxation carries a poor prognosis for repair of the rotator cuff tear and some consider it to be a pre- dictor of an irreparable tear. It usually is detected on computed tomography (CT) scans or MRI scan taken with the arm in neutral rotation but oc- casionally may be evident on axillary lateral radiographs. Static anterior subluxation usually is not associated with recurrent ante- rior shoulder instability. To develop a static anterior subluxation without any previous op- eration, it seems that a combination of a subscapularis tear, a su- praspinatus tear, and fatty degeneration of the infraspinatus mus- cle is necessary. An isolated tear of the subscapularis tendon and posterosuperior tears usually do not lead to anterior static sub- luxation. Current treatment attempts include repair of the supraspinatus tendon plus pectoralis major transfer with the transferred tendon being rerouted behind the conjoined tendon or a Latarjetlike pro- cedure to provide better anterior stability. This condition is most frequently but not al- ways associated with congenital dysplasia of the glenoid or with degenerative glenohumeral joint disease. Static posterior subluxa- tion may be associated with glenoid deformations such as classi- fied by Walch and co-workers. This static subluxation may be 64 7 Classifications of instability present without any rotator cuff deficiencies. To date, most authors have found static posterior subluxations to be irreversible. This may occur from trauma, neurologic injury, septic arthritis, or inadequate restoration of humeral length after arthroplasty. Inferi- or subluxation after trauma and surgery, if not associated with permanent nerve injury, usually resolves within 6 weeks but al- ways resolves within 2 years. Conversely, inferior subluxation caused by infection tends to result in joint surface destruction and only successful treatment of infection results in resolution of the inferior subluxation. Inferior subluxation cause by neurologic in- jury shortening of the humerus also remains symptomatic unless the primary problem can be resolved. Subluxation must be distinguished from traumatic inferior dis- location, which occasionally is encountered as luxatio erecta. This entity is part of the dynamic instabilities that can momentarily be reduced and may recur. Being able to passively displace the humeral head out the gle- noid fossa during physical examination does not describe instability but is a semiquantitative assessment of hyperlaxity. Such translation testing may be a sign of instability if it is significantly different from the asymptomatic side of if it is associated with symptoms of appre- hension.
The greatest hazards of accidental overdosage with epinephrine and norepinephrine are cardiac arrhyth- CLINICAL USES OF CATECHOLAMINES mias generic zyrtec 10 mg allergy forecast cambridge ma, excessive hypertension quality 10mg zyrtec allergy testing tray, and acute pulmonary The clinical uses of catecholamines are based on their edema. Large doses of isoproterenol can produce such actions on bronchial smooth muscle, blood vessels, and excessive cardiac stimulation, combined with a decrease the heart. Epinephrine is also useful for the treatment in diastolic blood pressure, that coronary insufﬁciency of allergic reactions that are due to liberation of hista- may result. It also may cause arrhythmias and ventricu- mine in the body, because it produces certain physio- lar ﬁbrillation. It is also employed in ophthalmology as a mydri- A number of adrenomimetic amines are not cate- atic agent. Some of these are directly acting amines to patients with closed-angle glaucoma before iridec- that must interact with adrenoceptors to produce a re- tomy, since further increases in intraocular pressure sponse in effector tissues. In dentistry, phenylephrine is used to pro- pounds, such as phenylephrine and methoxamine, acti- long the effectiveness of a local anesthetic. Drugs that exert their pharma- cological actions by releasing norepinephrine from its Dobutamine (Dobutrex), in contrast to dopamine, does neuronal stores (indirectly acting) produce effects that not produce a signiﬁcant proportion of its cardiac effects are similar to those of norepinephrine. They tend to ex- through the release of norepinephrine from adrenergic ert strong -adrenoceptor activity, but 1-adrenoceptor nerves; dobutamine acts directly on 1-adrenoceptors in activity typical of norepinephrine, such as myocardial the heart. Other amines are used as bronchodilators, while doses, it produces vasodilation of renal and mesenteric still others are used exclusively for their ability to stim- blood vessels. The indirectly acting Terbutaline and Albuterol drugs are effective only when given in large doses, and Terbutaline and albuterol are relatively selective 2- they often produce tachyphylaxis. Both have a longer duration of action than isoproterenol because they are not metabo- Directly Acting Adrenomimetic Drugs lized by COMT. Like isoproterenol, they are not me- Phenylephrine, Metaraminol, and Methoxamine tabolized by MAO and are not transported into adren- ergic neurons. Terbutaline and albuterol are effectively These drugs are directly acting adrenomimetic amines administered either orally or subcutaneously. Because that exert their effects primarily through an action on of their selectivity for -adrenoceptors, they produce 2 -adrenoceptors. Consequently, these agents have little less cardiac stimulation than does isoproterenol but are or no direct action on the heart. The pressor response is accom- to treat bronchial asthma and bronchospasm associated panied by reﬂex bradycardia, no change in the contrac- with bronchitis and emphysema (see Chapter 39). They do not precipitate cardiac arrhythmias and do dia, palpitations, headache, nausea, vomiting, and sweat- not stimulate the CNS. The frequency of appearance of these adverse ef- Phenylephrine is not a substrate for COMT, while fects is minimized, however, when the drugs are given metaraminol and methoxamine are not metabolized by by inhalation. Consequently, their duration of action is considerably longer than that of norepineph- Indirectly Acting Adrenomimetic Drugs rine. Following intravenous injection, pressor responses Ephedrine to phenylephrine may persist for 20 minutes, while pres- sor responses to metaraminol and methoxamine may Ephedrine is a naturally occurring alkaloid that can cross last for more than 60 minutes. They are used to re- ter effects are primarily due to its indirect actions and de- store or maintain blood pressure during spinal anesthe- pend largely on the release of norepinephrine. The reﬂex ephedrine may cause some direct receptor stimulation, bradycardia induced by their rapid intravenous injec- particularly in its bronchodilating effects. Because it re- tion has been used to terminate attacks of paroxysmal sists metabolism by both COMT and MAO, its duration atrial tachycardia. As is the nasal decongestant, although occasional nasal mucosal case with all indirectly acting adrenomimetic amines, 106 II DRUGS AFFECTING THE AUTONOMIC NERVOUS SYSTEM ephedrine is much less potent than norepinephrine; in insomnia, nervousness, nausea, vomiting, and emotional addition, tachyphylaxis develops to its peripheral actions. Ephedrine should not be Unlike epinephrine or norepinephrine, however, ephe- used in patients with cardiac disease, hypertension, or drine is effective when administered orally. Pharmacological Actions Amphetamine Ephedrine increases systolic and diastolic blood Amphetamine is an indirectly acting adrenomimetic pressure; heart rate is generally not increased. Ephedrine produces bronchial smooth logical effects are similar to those of ephedrine; how- muscle relaxation of prolonged duration when adminis- ever, its CNS stimulant activity is somewhat greater. Aside from pupillary dilation, ephedrine Both systolic and diastolic blood pressures are increased has little effect on the eye. Ephedrine is useful in relieving bronchoconstriction The therapeutic uses of amphetamine are based on and mucosal congestion associated with bronchial its ability to stimulate the CNS.
This effect cheap 5 mg zyrtec allergy symptoms of the throat, which m ay not be evident upon initial sym ptom s zyrtec 10mg discount allergy shots youtube, as well as cardiac sensitization (see adm inistration of the drug, is particularly beneﬁcial in H ypokalem ia). A ppropriate dietary and therapeutic m easures their utility in treating nephrogenic diabetes insipidus. The thiazides also possess som e diabetogenic whose kidneys fail to respond to A D H excrete large potential, and although pancreatitis during thiazide volum es of very dilute urine, not unlike those who have therapy has been reported in a few cases, the m ajor an A D H deﬁciency. The thiazides reduce glom erular ﬁl- m echanism contributing to the potential for glucose in- tration m odestly and decrease positive free water for- tolerance is not known. These actions com bine to cause patients with nephrogenic di- Hypokalem ia and Potassium -sparing abetes insipidus to excrete a som ewhat reduced urine Diuretics volum e with increased osm olality. Hypokalemia Absorption and Elimination The chronic use of som e diuretics m ay require the oral adm inistration of potassium supplem ents or potassium - O rally adm inistered thiazides are rapidly absorbed from sparing diuretics that reduce urinary K excretion. This the gastrointestinal tract and begin to produce diuresis is true especially for patients with congestive heart fail- in about 1 hour. A pproxim ately 50% of an oral dose is ure and cirrhosis, who are particularly sensitive to K excreted in the urine within 6 hours. The presence or absence of clinical sym ptom s of are organic acids and are actively secreted into the prox- hypokalem ia is quite closely related to serum K con- im al tubular ﬂuid by the organic acid secretory m echa- centrations, and even sm all changes in extracellular K nism. M ost patients begin to show their elim ination involving the hepatic–biliary acid se- sym ptom s when serum K levels fall below 2. Neurological sym ptom s include drowsiness, irritabil- The thiazides have a variable effect on elim ination ity, confusion, loss of sensation, dizziness, and com a. A dm inistration of thiazide diuret- lar weakness, cardiac arrhythm ias, tetany, respiratory ar- ics, especially at low doses, m ay elevate serum uric acid rest, and increased sensitivity of the m yocardium to dig- levels and cause goutlike sym ptom s. Clinical Uses Replacem ent should be gradual, with frequent evalua- Thiazides, especially hydrochlorothiazide (D yazide, tion of both serum K concentrations and cardiac activ- Esidrix, H ydroD IURIL, O retic), are useful adjunctive ity (electrocardiographic m onitoring). K supplem ents 21 Diuretic Drugs 247 can be adm inistered in several form s. W hen hypokalem ia is not attended by Product M anufacturer Dosage Form m etabolic alkalosis, other form s of K supplem entation Kaochlor A dria Liquid m ay be preferred. Since KCl solutions have a rather bit- Kay Ciel elixir Berlex Liquid ter and unpleasant taste, this salt was form erly given as Potassium Triplex Lilly Liquid an enteric-coated tablet. H owever, the rapid release of KCL 10% Purepac Liquid KCl from the tablet after it entered the sm all intestine KCL 20% Stanlabs Liquid K-Lor A bbott Powdera was responsible for a severe local ulceration, hem or- a K-Lyte M ead Johnson Tablets rhage, and stenosis, especially when there was a delay in gut transit tim e; therefore, the enteric-coated tablets aThis product, although supplied as a solid dose, is dissolved in water before ingestion. Sugar-coated products have been m arketed that contain KCl in a wax m atrix (Slow-K and Kaon-Cl) and helpful. Finally, the addition of a K -sparing diuretic to are purportedly slow- and controlled-release prepara- the therapeutic regim en m ay prove useful. A vailable evidence indicates that these slow- The three principal potassium -sparing diuretic release form s of KCl are occasionally capable of causing agents produce sim ilar effects on urinary electrolyte local tissue dam age and therefore probably should be com position. Solutions of tubule and collecting duct, they cause m ild natriuresis potassium gluconate, like the tablets, also have been as- and a decrease in K and H excretion. M icroencapsulated sim ilarities, these agents actually constitute two groups KCl preparations (M icro-K, K-D ur) that are neither en- with respect to their m echanism s of action. Aldosterone Antagonists: Spironolactone Consum ption of potassium -rich foods is the easiest and m ost generally advised m eans of counteracting a The m echanism by which Na is reabsorbed in coupled K deﬁcit. If K -rich A ldosterone and other com pounds with m ineralocorti- foods prove inadequate in replacing large quantities of coid activity bind to a speciﬁc m ineralocorticoid recep- the electrolyte or if the increased caloric intake that is tor in the cytoplasm of late distal tubule cells and of part of the dietary supplem entation is not desirable, principal cells of the collecting ducts. A listing receptor com plex is transported to the cell nucleus, of these solutions is given in Table 21. A lthough pa- where it induces synthesis of m ultiple proteins that are tients m ay ﬁnd m any of these products unpalatable, collectively called aldosterone-induced proteins. The their further dilution with water or fruit juice can be precise m echanism s by which these proteins enhance Na transport are incom pletely understood. H owever, the net effect is to increase Na entry across apical cell m em branes and to increase basolateral m em brane Na –K –A TPase activity and synthesis. Spironolactone thus blocks the hormone-induced Prunes (7) stimulation of protein synthesis necessary for Na reab- Banana (1) D ates (7) sorption and K secretion. Spironolactone, in the presence Figs (4) of circulating aldosterone, promotes a modest increase in Raisins (0.
Other fiber-containing enteral feedings are available to help regulate bowel function (En- rich cheap 10 mg zyrtec with amex allergy symptoms natural remedies, Jevity) cheap 5 mg zyrtec with mastercard allergy symptoms burning skin. Initiating Tube Feedings Guidelines for ordering enteral feedings are outlined in Table 11–5, page 218. Determine fluid requirements and volume tolerance based on overall status and concur- rent disease states. Monitor and assess nutritional status to evaluate the need for changes in the selected 11 regimen. The tube feeding can be given into the stomach (bolus, intermittent gravity drip, or continu- ous) or into the small intestine by continuous infusion (Table 11–6, page 219). Enteral nutri- tion is best tolerated when instilled into the stomach because this method produces fewer problems with osmolarity or feeding volumes. The stomach serves as a barrier to hyperos- molarity, thus the use of isotonic feedings is mandated only when instilling nutrients di- rectly into the small intestine. The use of gastric feedings is thus preferable and should be used whenever appropriate. Patients at risk for aspiration or with impaired gastric emptying may need to be fed past the pylorus into the jejunum or the duodenum. Feedings via a je- junostomy placed at the time of surgery can often be initiated on the first postoperative day, obviating the need for parenteral nutrition. Although enteral nutrition is generally safer than parenteral nutrition, aspiration can be a significant morbid event in the care of these patients. Appropriate monitoring for residual volumes in addition to keeping the head of the bed elevated can help prevent this complica- tion. Any transient postoperative ileus can best be treated by waiting for the ileus to resolve. Metoclopramide or erythromycin may be useful pharmacologic ther- apy for postop ileus (Chapter 22). Patients who have been tolerating feedings and develop intolerance should be carefully assessed for the cause. Feeding intolerance is characterized by vomiting, abdominal distention, diarrhea, or high gastric residual volumes. Complications of Enteral Nutrition Diarrhea: Diarrhea occurs in about 10–60% of patients receiving enteral feedings. The physician must be certain to evaluate the patient for other causes of diarrhea. Formula- related causes include contamination, excessively cold temperature, lactose intolerance, os- molality, and an incorrect method or route of delivery. Constipation: Although less common than diarrhea, constipation can occur in the enter- ally fed patient. Patients with ad- ditional requirements may benefit from water boluses or dilution of the enteral formulation. Aspiration: Aspiration is a serious complication of enteral feedings and is more likely to occur in the patient with diminished mental status. Further evaluate any patient who may have aspirated or who is assessed as being at increased risk for aspiration prior to instituting enteral feedings. Such patients may not be candidates for gastric feed- ings, and small-bowel feedings may be necessary. Drug Interactions: The vitamin K content of various enteral products varies from 22 to 156 mg/1000 Cal. This can significantly affect the anticoagulation profile of a patient re- ceiving warfarin therapy. Tetracycline products should not be administered 1 h before or 2 h 11 after enteral feedings to avoid the inhibition of absorption. Similarly, enteral feedings should be stopped 2 h before and after the administration of phenytoin. POSTOPERATIVE NUTRITIONAL SUPPORT Most patients can be started on oral feedings postoperatively, the question is when to begin them. Motility is delayed in patients un- dergoing laparotomy, whereas feedings begin fairly quickly for patients who undergo surgery on other parts of the body, once they recover consciousness sufficiently to protect their airway. Remember that the gut recovers motility as follows: The small intestine never loses motility (peristalsis is observed in the OR), the stomach regains motility about 24 h postoperatively, and the colon is the last to recover at 72–96 h postoperatively. Thus, by the time a patient reports flatus, one can assume that the entire gut has regained motility.
9 of 10 - Review by F. Felipe
Votes: 83 votes
Total customer reviews: 83