S. Kelvin. Notre Dame de Namur University.
They also should be reassured that 10 mg zyrtec with amex, while they will have some postoperative discomfort discount zyrtec 5 mg fast delivery, measures will be taken to assure that they will have adequate pain relief order zyrtec 5 mg on line. Perhaps the most useful intervention is for the smoking patient to cease smoking prior to surgery buy 10mg zyrtec overnight delivery. Cessation of cigarette smoking is very important for those who smoke more than 10 cigarettes per day. Short- term abstinence (48 hours) decreases the carboxyhemoglobin to that of a nonsmoker, abolishes the effects of nicotine on the cardiovascu- lar system, and improves mucosal ciliary function. Sputum volume decreases after 1 to 2 weeks of abstinence, and spirometry improves after about 6 weeks of abstinence. Nutritional There is a strong inverse correlation between the body’s protein status and postoperative complications in populations of patients undergoing elective major gastrointestinal surgery and, to a lesser extent, other forms of surgery. With this in mind, it would seem useful to assess the nutritional status of a patient prior to surgery and possibly intervene preoperatively if a deficit is unmasked. While this makes intuitive sense, there in not much evidence to support improved clinical outcome via aggressive nutritional supportive measures. While there are many clinical and laboratory measures that can help assess a patient’s nutritional status, there is no “gold standard. Ciocca ual markers may not accurately represent the nutritional status of the patient. Preoperative weight loss is an important historical factor to obtain, if possible. In general, a weight loss of 5% to 10% over a month or 10% to 20% over 6 months is associated with increased complica- tions from an operation. A more thorough history of weight loss in the patient in the case presented at the beginning of this chapter will be important. While no one marker is predictive of surgical outcome, combinations of measurements have been used to quantify the risk for subsequent complications. Because delayed hypersensitivity is uncommon in clinical practice, the equation has been simplified by substituting the lymphocyte score, using a scale of 0 to 2, where 0 is less than 1000 total lymphocytes/mm3, 1 is 1000 to 2000 total lymphocytes/mm3, and a score of 2 is more than 2000 total lymphocytes/mm3. The higher the score using either of these equa- tions, the greater the risk of postoperative complications. It is important to take the patient’s nutritional state into consideration after surgery. In the majority of well-nourished patients, little needs to be done other than to ensure that they resume a normal diet as soon as possible after surgery, preferably within 5 to 10 days. In patients who are severely malnourished, aggressive nutritional support may be of some benefit, with most of the benefit occurring in the early postoperative period. Hematologic An obvious concern for a surgeon who is about to induce iatrogenic injury to a patient is that of bleeding and the patient’s inherent ability to form clots. On the one hand, the surgeon depends on it so that the patient does not exsanguinate from the intervention (fortu- nately, an exceedingly rare event). Conversely, a patient in a hyper- coaguable state may suffer from a thromboemblic event that could be life threatening. In addition, a growing number of patients requiring surgical intervention are chronically anticoagulated for a number of reasons, e. Historical information of importance includes whether the patient or a family member has had a prior episode of bleeding or a throm- boembolic event, and whether the patient has a history of prior 1. Perioperative Care of the Surgery Patient 13 transfusions, prior surgery, heavy menstrual bleeding, easy bruising, frequent nosebleeds, or gum bleeding after brushing teeth. If the history is negative and the patient has not had a previous significant hemostatic challenge, then the like- lihood of a bleeding or thrombotic event is exceedingly rare and the value of preoperative coagulation testing is low. This underscores the importance of adopting a rea- sonable strategy of ordering only those diagnostic tests indicated by the patient’s history. If a clinically important coagulopathy is identi- fied, therapeutic strategies for management of various coagulation dis- orders in preparation for surgery are listed in Table 1. A good deal of the planning hinges upon how urgently the surgery needs to be performed and the indication for the anticoagula- tion. Most patients who take warfarin and who are to undergo ambu- latory or same-day admission elective surgery can be managed simply by having them discontinue their warfarin for several days prior to surgery.
Your body then responds with a full- system alert known as the fight-or-flight response order 10 mg zyrtec amex. Chapter 3: Sorting Through the Brain and Biology 39 Preparing to Fight or Flee When danger presents itself generic 10mg zyrtec visa, you reflexively prepare to stand and fight or run like you’ve never run before buy zyrtec 10mg mastercard. Your body responds to threats by preparing for action in three different ways: physically discount zyrtec 5 mg visa, mentally, and behaviorally. It tells the adrenal glands to rev up production of adrena- line and noradrenaline. Your heart pounds faster and you start breathing more rapidly, sending increased oxygen to your lungs while blood flows to the large muscles, preparing them to fight or flee from danger. All senses on high alert, scan for more danger Pupils widen to Brain sends message to let in more light nervous system to get ready Sweating increases, keeping body cool and slippery so aggressor can’t grab hold Heart beats harder and faster Digestion stops to Lungs pull in more oxygen, allow more energy preparing for movement for fight or flight Muscles tense, poised Adrenal glands pump Figure 3-1: potent adrenaline Blood flow decreases to hands and noradrenaline and feet so they won’t bleed as When much if injured; also increases presented blood flow to large muscles with danger, your body prepares Blood flow increases itself to flee to large muscle groups in arms and legs for better or stand and kicking, hitting, and running fight. Those pening in reality — affects the immune system who felt themselves to be at a lower status and the tendency to come down with colds. Sheldon Cohen and colleagues nomic status were not so predictive of who have conducted research on the role of stress would get colds. He then exposed the par- These studies show that the mind and body ticipants to the cold virus. Other research high stress came down with colds at far higher has been consistent with this idea, showing rates than the volunteers who reported having that stress also slows wound healing, dimin- low stress. In other words, the A more recent study reported in the journal way people think about things that happen to Health Psychology (2008) found that people’s them strongly affects their bodies. Blood flow decreases to hands and feet to minimize blood loss if injured and keep up the blood supply to the large muscles. Sweating increases to keep the body cool, and it makes you slippery so aggressors can’t grab hold of you. When you have to take on a bear, a lion, or a warrior, you’d better have all your resources on high alert. Unfortunately, your body reacts too easily with the same preparation to fight traffic, meet deadlines, speak in public, and cope with other everyday worries. When human beings have nothing to fight or run from, all that energy has to be released in other ways. Chapter 3: Sorting Through the Brain and Biology 41 Most experts believe that experiencing these physical effects of anxiety on a frequent, chronic basis doesn’t do you any good. Various studies have sug- gested that chronic anxiety and stress contribute to a variety of physical prob- lems, such as abnormal heart rhythms, high blood pressure, irritable bowel syndrome, asthma, ulcers, stomach upset, acid reflux, chronic muscle spasms, tremors, chronic back pain, tension headaches, a depressed immune system, and even hair loss. Before you get too anxious about your anxiety, please realize that chronic anxiety contributes to many of these problems, but we don’t know for sure that it’s a major cause of them. Nevertheless, enough studies have suggested that anxiety or stress can make these disorders worse to warrant taking chronic anxiety seriously. Chronic tension headaches — may contribute to high blood pressure, which could lead to stroke Teeth grinding Chronic shoulder pain, back pain Chest pain, abnormal heart rhythms Suppressed immune system, increases risk of colds, infections May trigger asthma Ulcers, stomach upset, acid reflux Irritable bowel syndrome Tremors Muscle spasms in legs, back, or shoulders Figure 3-2: The chronic effects of anxiety. In fact, excess stress can deliver another wallop: many of them are the same techniques that you People with long-lasting stress are significantly can read about in this book. This isn’t The amazing result of this study was that the surprising, because stress increases the levels glucose levels of those who found out how to of glucose (sugar) in the bloodstream. So if you don’t have when stress management was added to the diabetes, protect yourself by overcoming anxi- care of adults with diabetes, their blood sugar ety, and if you do have diabetes, know that calm readings actually went down. Mimicking Anxiety: Drugs, Diet, and Diseases As common as anxiety disorders are, believing that you’re suffering from anxiety when you’re not is all too easy. Prescription drugs may have a vari- ety of side effects, some of which mimic some of the symptoms of anxiety. Various medical conditions also produce symptoms that imitate the signs of anxiety.
Their research has aimed at the discovery of hydrogels that display a sudden change in properties in response to environmental stimuli including pH generic zyrtec 5 mg on line, temperature generic zyrtec 5 mg free shipping, ionic strength purchase 10mg zyrtec, electromagnetic radiation discount zyrtec 5 mg free shipping, electric fields, shear, sonic radiation, enzyme substrates or affinity ligands. Variations in the chemical structure of a hydrogel and the composition of a solvent make it possible to fabricate such responsive hydrogels. For example, a hydrogel can either swell a hundred times in volume or collapses in response to a subtle change in temperature as little as a 1 °C. Other hydrogels do not swell or collapse, but their physical property changes from sol to gel or vice versa. Due to the softness and flexibility of hydrogels, a hydrogel- based implantable device would provide minimal friction to surrounding tissues and house delicate materials, especially proteins or cells, without causing damage to them. The low interfacial tension between the hydrogel surface and biological fluids would minimize protein adsorption and cell adhesion, thereby displaying excellent biocompatibility. The SmartGel, previously mentioned in the context of vaginal drug delivery, is an example of temperature-sensitive hydrogels. It is a viscoelastic soft gel at room temperature but becomes much firmer at body temperature. This interesting property allows the gel to be used as a shoe insert to tailor the shape of the shoe to the need of an individual wearer. An aqueous solution of poly(N-isopropylacrylamide) has a critical transition temperature at 32 ~ 37 °C. Above the critical transition temperature, however, polymer strands interact with one another to make a gel structure. A similar change is also observed with the graft copolymer of poly(N-isopropylacrylamide) and polyacry lamide. Its interesting gellation tendency is utilized to immobilize cells inside the gel matrix. For example, a polymeric solution containing islets of Langerhans (insulin-releasing pancreatic cells) is loaded into a pouch with a semipermeable membrane. When the pouch is implanted, the solution becomes a gel to serve as a matrix to immobilize the cells. Responding to rising glucose levels in diabetic patients, the islets would secrete insulin to maintain a normal glycemic level. It was demonstrated that free islets of Langerhans dispersed in a solution tended to aggregate and lost their viability quickly, while the cells immobilized in the gel matrix remained intact and viable much longer. Graft copolymers of poloxamers and either poly(acrylic acid) or chitosan change from a sol to a gel at temperature above 37 °C. The appearing gel forms a stable matrix that can retain a drug for its sustained release. At room temperature, gellation is followed by a further increase in the polymer concentration due to packing of the micelles. Interestingly, the gel is changed into a sol at an elevated temperature such as 45 °C. Upon subcutaneous injection of the polymeric solution into the body (37 °C), a gel is formed immediately. If a drug is dissolved in the polymeric solution prior to the injection, the gel would function as a sustained release matrix for the entrapped drug. The critical gel-sol transition temperature is conveniently modified by varying the length of each block and molecular weight of the triblock polymer. An application of such technology has been in the development of biomimetic secretory granules for drug delivery applications. Secretory granules within certain cells consist of a polyanionic polymer network encapsulated within a lipid membrane. The polymer network, which contains biological mediators such as histamine, exists in a collapsed state as a consequence of the internal pH and ionic content which is maintained by the lipid surrounding the granule. Release of histamine from such granules is initiated through the fusion of the granule with the cell membrane exposing the polyanionic internal matrix to the extracellular environment. The change in pH and ionic strength results in ion exchange and swelling of the polyanionic network which in turn causes release of the endogenous mediators. An environmentally responsive, hydrogel microsphere coated with a lipid bilayer has recently been shown to act as a secretory granule mimic (Figure 16. Disruption of the lipid bilayer by electroporation was shown to cause the microgel particles to swell and release their drug.
The signs and symptoms of hyponatremia and hypernatremia can be detected clinically (Table 4 5 mg zyrtec with mastercard. Under such circumstances buy 10 mg zyrtec otc, mixed volume and concentration abnormalities often occur purchase zyrtec 5 mg amex. Conse- quently generic zyrtec 10mg, it is important that volume status is assessed initially before any conclusion as to changes in concentration or composition is ascribed. Sodium Excess In surgical patients, this condition is caused primarily by excess sodium intake (as may occur with infusion of isotonic saline) and renal retention. Treatment of sodium excess includes eliminating or reducing sodium intake, mobilization of edema fluid for renal excre- tion (such as osmotic diuretics for fluid and solute diuretics for sodium), and treatment of any underlying disease that enhances sodium retention. An algorithm for assessment of fluid status and acute sodium changes is shown in Algorithm 4. Sodium Deficit In the surgical patient, this condition usually occurs via loss of sodium without adequate saline replacement. Several additional sources of sodium loss should be considered, including gastrointesti- nal fluids and skin. Third-space losses of sodium (and water) also can be extensive after major injury or operation. The symptoms and signs of sodium deficit arise from hypovolemia and reduced tissue perfu- sion. Under such circumstances, urine sodium is low (<15mEq/L) and osmolarity is increased (>450mOsm/L). If hypotension is present, this must be treated with normal saline or lactated Ringer’s 4. A mild sodium deficit without symptoms may be treated over several days if the losses of sodium have been reduced. Administration of fluids for water and sodium requires knowledge of the current fluid and electrolyte status of the patient, understanding of the level of stress, and appreciation for actual or potential sources of ongoing fluid and electrolyte losses. Having estimated the fluid and sodium status of the patient, administration of appropriate volumes of water and sodium usually is done by the intravenous route. Standard solutions of known contents nearly always are used, and the prescrib- ing physician must be familiar with these basic formulas (Table 4. Abnormalities of other electrolytes (K, Ca, P, Mg: see Abnormalities of Electrolytes, below) usually require specific fluid solutions or addition of these ions to standard solutions. Changes in acid–base balance also may require special alkalotic or acidotic solutions to correct these abnormalities (Tables 4. Solution 1 is made by taking 800mL of 5% D/W and adding four ampules of 50mL (200mL) of 7. Disorders of Composition By definition, composition changes include alterations in acid–base balance plus changes in concentration of potassium, calcium, magne- sium, and phosphate. Acid–Base Balance There are four major buffers in the body: proteins, hemoglobin, phos- phate, and bicarbonate. All serve to maintain the hydrogen ion con- centration within a physiologic range. Respiratory acid–base abnormalities are identified readily by determination of Paco2. By contrast, there are no definitive means to identify a “metabolic” acid–base abnormality. The first is the concept of anion gap, which is used to iden- tify a nonvolatile or fixed acid–base abnormality. Metabolic acidosis is the most common reason for increases with accumulation of anions such as lactate, acetoacetate, sulfates, and phosphates. Base excess measures the amount of nonvolatile acid loss or extra base that has increased the total buffer base.