By R. Roland. Webster University North Florida.

Insulin increases cellular uptake of potassium best when high insulin levels are achieved by intravenous injection of 5 to 10 units of regular insulin order vantin 100 mg with amex, accompanied by 50 mL of 50% glucose purchase 200 mg vantin with visa. Salbutamol cheap 100 mg vantin with visa, a selective β -agonist purchase vantin 100mg on line, decreases serum potassium acutely by 1 mEq/L or more2 when given by inhalation or intravenously, although cardiac dysrhythmias may occasionally complicate treatment with selective β -agonists. Sodium polystyrene sulfonate resin (Kayexalate), which exchanges sodium for potassium, can be given orally (30 to 60 g)154 or as a retention enema (50 g in 200 mL of 20% sorbitol). Hemodialysis and continuous renal replacement therapy may be necessary for patients with acute kidney injury or chronic renal failure. Circulating calcium consists of a protein-bound fraction (40% to 50%), a fraction bound to inorganic anions (10% to 15%), and an ionized fraction (45% to 50%), which is the physiologically active and homeostatically regulated component. In general, calcium is essential for all movement that occurs in mammalian systems. Essential for normal excitation–contraction coupling, calcium is also necessary for proper function of muscle tissue, ciliary movement, mitosis, neurotransmitter release, enzyme secretion, and hormonal secretion. Calcium is important both for generation of the cardiac pacemaker activity and for generation of the cardiac action potential and therefore is the primary ion responsible for the plateau phase of the action potential. Vitamin D, after ingestion or cutaneous manufacture under the stimulus of ultraviolet light, is 25-hydroxylated to calcidiol in the liver and then is 1-hydroxylated to calcitriol, the active metabolite, in the kidney. Permanent hypocalcemia occurs in about 5% of patients who undergo thyroidectomy, with the incidence somewhat higher in patients who undergo central neck dissection. Vitamin D deficiency may result from lack of dietary vitamin D or from vitamin D malabsorption in patients who lack sunlight exposure. Hyperphosphatemia- induced hypocalcemia may occur as a consequence of overzealous phosphate therapy, from cell lysis secondary to chemotherapy, or as a result of cellular destruction from rhabdomyolysis. Alkalemia resulting from hyperventilation or sodium bicarbonate injection can acutely decrease [Ca2+]. In massive transfusion, citrate may produce hypocalcemia by chelating calcium; however, decreases are usually transient and produce negligible cardiovascular effects, unless citrate clearance is decreased (e. In massive transfusion, a high proportion of patients develop moderate or severe hypocalcemia. Early symptoms include sensations of numbness and tingling involving fingers, toes, and the circumoral region. In frank tetany, tonic contraction of respiratory muscles may lead to laryngospasm, bronchospasm, or respiratory arrest. Mental status alterations include irritability, depression, psychosis, and dementia. Reduced ionized serum calcium occurs in as many as 88% of critically ill patients, 66% of less severely ill intensive care unit patients, and 26% of 1058 hospitalized non–intensive care unit patients. Table 16-20 Hypocalcemia: Clinical Manifestations Initial diagnostic evaluation should concentrate on history and physical examination, laboratory evaluation of renal function, and measurement of serum phosphate concentration. Latent hypocalcemia can be diagnosed by tapping on the facial nerve to elicit Chvostek sign or by inflating a sphygmomanometer to 20 mmHg above systolic pressure, which produces radial and ulnar nerve ischemia and causes carpal spasm known as Trousseau sign. The differential diagnosis of hypocalcemia can be approached by addressing four issues: age of the patient, serum phosphate concentration, general clinical status, and duration of hypocalcemia. An otherwise healthy patient with chronic hypocalcemia probably is hypoparathyroid. In renal insufficiency, reduced phosphorus excretion results in hyperphosphatemia, which downregulates the 1α-hydroxylase responsible for the renal conversion of calcidiol to calcitriol. This, in combination with decreased production of calcitriol secondary to reduced renal mass, causes reduced intestinal absorption of calcium and hypocalcemia. The definitive treatment of hypocalcemia necessitates identification and treatment of the underlying cause (Table 16-21). Hypocalcemia resulting from hypomagnesemia or hyperphosphatemia is treated by repletion of magnesium or removal of phosphate. Treatment of a patient who has tetany and hyperphosphatemia requires coordination of therapy to avoid the consequences of metastatic soft-tissue calcification. Potassium and other electrolytes should be measured and abnormalities should be corrected. Hyperkalemia and hypomagnesemia potentiate hypocalcemia-induced cardiac and neuromuscular irritability. In contrast, hypokalemia protects against hypocalcemic tetany; therefore, correction of hypokalemia without correction of hypocalcemia may provoke tetany. For instance, in most patients after cardiac surgery, administration of calcium only increases blood pressure and actually attenuates the β-adrenergic effects of epinephrine. Therefore, calcium infusions should be of limited value in surgical patients unless there is demonstrable evidence of ionized hypocalcemia. Calcium salts appear to confer no benefit to patients already receiving inotropic or vasoactive agents. The cornerstone of therapy for confirmed, symptomatic, ionized hypocalcemia ([Ca2+] < 0. In patients who have severe hypocalcemia or hypocalcemic symptoms, calcium should be administered intravenously. In emergency situations, in an averaged-sized adult, the “rule of 10s” advises infusion of 10 mL of 10% calcium gluconate (93 mg elemental calcium) over 10 minutes, followed by a continuous infusion of elemental calcium, 0. Calcium salts should be diluted in 50 to 100 mL D W (to limit venous irritation and thrombosis), should not be mixed5 with bicarbonate (to prevent precipitation), and must be given cautiously to digitalized patients because calcium increases the toxicity of digoxin. During calcium replacement, clinicians should monitor serum calcium, magnesium, phosphate, potassium, and creatinine. Urinary calcium should be monitored in an attempt to avoid hypercalciuria (>5 mg/kg/24 hr) and urinary tract stone formation. Although the principal effect of vitamin D is to increase enteric calcium absorption, osseous calcium resorption is also enhanced. When rapid changes in dosage are anticipated or an immediate effect is required (e. Because the effect of vitamin D is not regulated, the dosages of calcium and vitamin D should be adjusted to raise the serum calcium into the low normal range. Adverse reactions to calcium and vitamin D include hypercalcemia and hypercalciuria. If hypercalcemia develops, calcium and vitamin D should be discontinued and appropriate therapy given. The toxic effects of vitamin D metabolites persist in proportion to their biologic half-lives (ergocalciferol, 20 to 60 days; dihydrotachysterol, 5 to 15 days; calcitriol, 2 to 10 days). In hypoalbuminemic patients, total serum calcium can be estimated (albeit inaccurately) by assuming an increase of 0. Severe hypercalcemia (total serum calcium > 13 mg/dL) is associated with more severe neuromyopathic 1061 symptoms, including muscle weakness, depression, impaired memory, emotional lability, lethargy, stupor, and coma. The cardiovascular effects of hypercalcemia include hypertension, arrhythmias, heart block, cardiac arrest, and digitalis sensitivity. Skeletal disease may occur secondary to direct osteolysis or humoral bone resorption. In response to hypovolemia, renal tubular reabsorption of sodium enhances renal calcium reabsorption. Effective treatment of severe hypercalcemia is necessary to prevent progressive dehydration and renal failure leading to further increases in total serum calcium, because volume depletion exacerbates hypercalcemia.

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There is a centralized resource for74 obtaining these and other guidelines at the Equator-Network buy vantin 200mg cheap. Academic anesthesia needs more workers to immerse themselves in these statistical fundamentals buy vantin 100mg lowest price. Having done so proven vantin 200 mg, these statistically knowledgeable academic anesthesiologists will be prepared to improve their own research projects 200 mg vantin sale, to assist their colleagues in research, to efficiently seek consultation from the professional statistician, to strengthen the editorial review of journal articles, and to expound to the clinical reader the whys and wherefores of statistics. The clinical reader also needs to expend his or her own effort to acquire some basic statistical skills. Journals are increasingly difficult to understand without some basic statistical understanding. Finally, understanding principles of experimental design and statistical inference can prevent premature acceptances of new therapies from faulty studies. The unpredictability paradox: review of empirical comparisons of randomised and non-randomised clinical trials. Different methods of allocation to groups in randomized trials are associated with different levels of bias: a meta- epidemiological study. Empirical evidence of bias: dimensions of methodological quality associated with estimates of treatment effects in controlled trials. Effect of formal statistical significance on the credibility of observational associations. A comparison of Bayes-Laplace, Jeffreys, and other priors: the case of zero events. Risk scores for predicting postoperative nausea and vomiting are clinically useful tools and should be used in every patient. Effective management of postoperative nausea and vomiting: let us practise what we preach! Risk scores for predicting post-operative nausea and vomiting are clinically useful tools and should be used in every patient: ‘Don’t throw the baby out with the bathwater. Independent predictors from stepwise logistic regression may be nothing more than publishable p values. Advances in measuring the effect of individual predictors of cardiovascular risk: the role of reclassification measures. Assessing the performance of prediction models: a framework for traditional and novel measures. A randomized control trial of right-heart catheterization in critically ill patients. The effectiveness of right heart catheterization in the initial care of critically ill patients. Epidural anaesthesia and survival after intermediate-to-high risk non-cardiac surgery: a population-based cohort study. Propensity scores in intensive care and anaesthesiology literature: a systematic review. Increased mortality, postoperative morbidity, and cost after red blood cell transfusion in patients having cardiac surgery. Evidence-based practice: how to perform and use systematic reviews for clinical decision-making. Systematic reviews of anesthesiologic interventions reported as statistically significant: problems with power, precision, and type 1 error protection. Statistically significant meta-analyses of clinical trials have modest credibility and inflated effects. A study of the deaths associated with anesthesia and surgery: based on a study of 599548 anesthesias in ten institutions 1948–1952, inclusive. Possible association between halothane anesthesia and postoperative hepatic necrosis. Reassessing Google Flu Trends data for detection of seasonal and pandemic influenza: a comparative epidemiological study at three geographic scales. University of Queensland vital signs dataset: development of an accessible repository of anesthesia patient monitoring data for research. What your future doctor should know about statistics: must-include topics for introductory undergraduate biostatistics. Antibiotic prophylaxis has become standard for surgeries in which there is more than a minimum risk of infection. The most commonly used antibiotic for surgical prophylaxis is cefazolin, a first-generation cephalosporin, as the potential pathogens for most surgeries are gram-positive cocci from the skin. Anesthesiologists should work in consultation 501 with surgeons to use guidelines determined by the local infection control committee to take initiative for administering prophylactic antibiotics because they have access to the patient during the 60 minutes prior to incision and can optimize timing of administration. Peripheral vasoconstriction, which results from central sympathetic control of subcutaneous vascular tone, is probably the most frequent and clinically the most important impediment to wound oxygenation and wound healing. All vasoconstrictive stimuli must be corrected simultaneously to allow optimal healing. Modifiable risks for wound infections include smoking, malnutrition, obesity, hyperglycemia, hypercholesterolemia, and hypertension. Maintenance of a high room temperature or active warming before, during, and after the operation is significantly more effective than other methods of warming, such as application of warmed blankets, circulating water blankets placed on the surface of the operating table, and humidification of the breathing circuit. Current best recommendations for volume management include replacing fluid losses based on standard recommendations for the type of surgery, replacement of blood loss, and replacement of other ongoing fluid losses (e. Pain control also appears important since it favorably influences both pulmonary function and vascular tone. Wound complications are associated with2 prolonged hospitalization, increased resource consumption, and even increased mortality. A growing body of literature supports the concept that patient factors are a major determinant of wound outcome following surgery. Comorbidities such as diabetes and cardiac disease clearly contribute, and a patient’s genetic make-up may also contribute. Environmental stressors and3 the individual response to stress are also important. In particular, wounds are exquisitely sensitive to hypoxia, which is both common and preventable. Perioperative management can be adapted to promote postoperative wound healing and resistance to infection. Along with aseptic technique and prophylactic antibiotics, maintaining perfusion and oxygenation of the wound is paramount. This chapter discusses how knowledge of the principles of infection control and the biology and physiology of wound repair and resistance to infection can improve outcomes. The graph shows the distribution of adverse events within the subcategory of operative care (7,716 operative adverse events).

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Two laryngoscopes that closely resembled modern L-shaped instruments were designed in 1910 and 1913 by two American surgeons purchase 200mg vantin fast delivery, Henry Janeway and George Dorrance 200mg vantin mastercard, but neither instrument achieved lasting use despite their excellent designs cheap 100 mg vantin with amex. This challenge was made somewhat easier vantin 200 mg low cost, however, with the advent of laryngoscope blades specifically designed to increase visualization of the vocal cords. Robert Miller of San Antonio, Texas, and Robert Macintosh of Oxford University created their respectively named blades within an interval of 2 years. In 1941, Miller brought forward the 64 slender, straight blade with a slight curve near the tip to ease the passage of the tube through the larynx. Although Miller’s blade was a refinement, the technique of its use was identical to that of earlier models as the epiglottis was lifted to expose the larynx. Sir Robert Macintosh later described the circumstances of its discovery in an appreciation writing regarding the career of his technician, Mr. As Sir Robert recalled, “A Boyle-Davis gag, a size larger than intended, was inserted for tonsillectomy, and when the mouth was fully opened the cords came into view. This was a surprise since conventional laryngoscopy, at that depth of anaesthesia, would have been impossible in those pre-relaxant days. Within a matter of hours, Salt had modified the blade of the Davis gag and attached a laryngoscope handle to it; and streamlined (after testing several models), the end result came into widespread use. The most distinguished innovator in tracheal intubation was the self- trained British anesthetist Ivan (later, Sir Ivan) Magill. In 1919, while34 serving in the Royal Army as a general medical officer, Magill was assigned to a military hospital near London. Although he had only rudimentary training in anesthesia, Magill was obliged to accept an assignment to the anesthesia service, where he worked with another neophyte, Stanley Rowbotham. Together, Magill and Rowbotham attended casualties35 disfigured by severe facial injuries who underwent repeated restorative operations. These procedures required that the surgeon, Harold Gillies, have unrestricted access to the face and airway. These patients presented formidable challenges, but both Magill and Rowbotham became adept at tracheal intubation and quickly understood its current limitations. Because they learned from fortuitous observations, they soon extended the scope of tracheal anesthesia. They gained expertise with blind nasal intubation after they learned to soften semirigid insufflation tubes for passage through the nostril. Even though their original intent was to position the tips of the nasal tubes in the posterior pharynx, the slender tubes frequently ended up in the trachea. Stimulated by this chance experience, they developed techniques of deliberate nasotracheal intubation. In 1920, Magill devised an aid to manipulating the catheter tip, the “Magill angulated forceps,” which continues to be manufactured according to his original design over 90 years ago. With the war over, Magill entered civilian practice and set out to develop a wide-bore tube that would resist kinking but be conformable to the contours of the upper airway. While in a hardware store, he found mineralized red 65 rubber tubing that he cut, beveled, and smoothed to produce tubes that clinicians around the world would come to call “Magill tubes. Magill also rediscovered the advantage of applying cocaine to the nasal mucosa, a technique that greatly facilitated awake blind nasal intubation. In 1926, Arthur Guedel began a series of experiments that led to the introduction of the cuffed tube. Guedel transformed the basement of his Indianapolis home into a laboratory, where he subjected each step of the preparation and application of his cuffs to a vigorous review. He fashioned36 cuffs from the rubber of dental dams, condoms, and surgical gloves that were glued onto the outer wall of tubes. Using animal tracheas donated by the family butcher as his model, he considered whether the cuff should be positioned above, below, or at the level of the vocal cords. He recommended that the cuff be positioned just below the vocal cords to seal the airway. Ralph Waters later recommended that cuffs be constructed of two layers of soft rubber cemented together. These detachable cuffs were first manufactured by Waters’ children, who sold them to the Foregger Company. He first filled the mouth of an anesthetized and intubated patient with water and showed that the cuff sealed the airway. Even though this exhibition was successful, he searched for a more dramatic technique to capture the attention of those unfamiliar with the advantages of intubation. He reasoned that if the cuff prevented water from entering the trachea of an intubated patient, it should also prevent an animal from drowning, even if it were submerged under water. To encourage physicians attending a medical convention to use his tracheal techniques, Guedel prepared the first of several “dunked dog” demonstrations (Fig. An anesthetized and intubated dog, Guedel’s own pet, “Airway,” was immersed in an aquarium. After the demonstration was completed, the anesthetic was discontinued before the animal was removed from the water. According to legend, Airway awoke promptly, shook water over the onlookers, saluted a post, then trotted from the hall to the applause of the audience. After a patient experienced an accidental endobronchial intubation, Ralph Waters reasoned that a very long cuffed tube could be used to isolate the lungs. On learning of his friend’s success with intentional one-lung37 anesthesia, Arthur Guedel proposed an important modification for chest surgery, the double-cuffed single-lumen tube, which was introduced by Emery Rovenstine. These tubes were easily positioned, an advantage over bronchial blockers that had to be inserted by a skilled bronchoscopist. The 66 double-lumen tube currently most popular was designed by Frank Robertshaw of Manchester, England, and is prepared in both right- and left-sided versions. Robertshaw tubes were first manufactured from mineralized red rubber but are now made of extruded plastic, a technique refined by David Sheridan. Sheridan was also the first person to embed centimeter markings along the side of tracheal tubes, a safety feature that reduced the risk of the tube’s being incorrectly positioned. In 1928, a rigid bronchoscope was specifically designed for examination of the large airways. Although it was known in 1870 that a thread of glass could transmit light along its length, technologic limitations were not overcome until 1964, when Shigeto Ikeda developed the first flexible fiberoptic bronchoscope. Fiberoptic-assisted tracheal intubation has become a common approach in the management of patients with difficult airways having surgery. Roger Bullard desired a device to simultaneously examine the larynx and intubate the vocal cords. He had been frustrated by failed attempts to visualize the larynx of a patient with Pierre-Robin syndrome. In response, he developed the Bullard laryngoscope, whose fiberoptic bundles lie beside a curved blade.

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