Adenosine: a new antihy- metastatic disease buy sildalist 120mg overnight delivery, it is possible to predict metastatic pertensive agent during pheochromocytoma removal safe 120 mg sildalist. Malignant pheochromocytoma: clinical purchase 120mgmg sildalist with amex, biological, histologic and thera- tissue is not possible, the tumor will recur and even- peutic data in a series of 20 patients with distant metastases. Treatment of malignant pheochromocytomas with 131-1 metaiodobenzylguanidine ment, if scintigraphy is positive, and chemotherapy, and chemotherapy. On sagittal images of the same tu- mor (line markings), it is seen to be suprarenal and Figure 75. Beware of needle aspiration of unexpected pheochromocytoma because sudden death has been Differential Diagnosis reported in this context. The differential diagnosis includes benign and ma- lignant adrenal medullary and cortical tumors as well as metastatic breast cancer to the adrenal Case Continued gland. The workup of an incidentaloma is designed to This patient has elevated urinary and plasma-free address two issues that may require surgical inter- levels of catecholamines. Hormonally functional Diagnosis and Recommendation tumors include those with excessive secretion of al- The diagnosis is pheochromocytoma. The patient dosterone, cortisol, male or female hormones, and should be prepared with alpha-blockade followed by catecholamines. Aldosteronoma is excluded by beta-blockade and scheduled for right adrenalec- measuring serum levels of potassium (K ), as long as tomy. Moreover, 24-hour urine levels of hydro- The patient is started on phenoxybenzamine at 10 cortisone or free cortisol should be measured before mg orally twice daily, and is instructed to drink at and following low-dose dexamethasone. After 3 to 5 days, the with Cushing syndrome will not suppress levels fol- dose of phenoxybenzamine is increased to 10 mg lowing low-dose dexamethasone, while normal in- three times daily. This patient did not have elevated later, her pulse rate increases to 120 beats per urinary levels of free cortisol and reduced levels af- minute and propranolol is started and increased to ter dexamethasone. The blood pressure should metanephrine, normetanephrine, and total cate- be titrated with phenoxybenzamine to normal cholamines. After approximately 2 to 3 weeks, the patient pheochromocytoma is measurement of blood levels is ready for surgery. The anesthesiologist has placed an arterial catheter The issue of malignancy is determined primarily and a central venous catheter. A critical criterion through a bilateral subcostal incision, and the right for the diagnosis of adrenal cortical cancer is tumor lobe of the liver is completely mobilized to expose weight >100 g, which equals a diameter of 6 cm. The adrenal vein is ligated Tumors that are >4 cm in diameter should be re- early in the operation to avoid episodes of severe moved based on the possibility that they may be hypertension. Alternatively, a laparoscopic right adrena- they have increased in size, they should be re- lectomy may be used because it results in less pain moved. For this patient with a history of breast can- postoperatively and is associated with a more rapid cer, if the biochemical studies exclude pheochromo- recovery. However, it may not be indicated for large cytoma and there is no other site of disease, the tumors that are potentially malignant. Pheochro- tumor could be aspirated to diagnose breast cancer mocytomatosis has been reported as a complication metastases to the adrenal. The classic patient describes “spells” of paroxysmal headaches, pallor, palpitations, hyper- Pheochromocytomas are rare tumors that secrete ex- tension, and diaphoresis. Extra-ad- The diagnosis of pheochromocytoma is based renal tumors are more likely to be cancerous. Certainly the blood measure- renal pheochromocytomas and no other manifesta- ment greatly facilitates the workup and is accurate. The compound is similar to norepinephrine pheochromocytomas indicate that the right adre- and is taken up by vesicular monoamine trans- nal gland harbors a tumor more often than the left porters. Pheochromocytomas usually measure be- for pheochromocytoma is 100% and the specificity tween 3 and 5 cm in diameter and weigh <100 g. Tumors are tan to gray in color and have a soft con- Once the diagnosis is established and the tumor sistency. Larger tumors are cystic and have necrosis localized, preoperative preparation includes alpha- or calcification. Patients are started on phenoxy- tomas are usually arranged in cords or alveolar pat- benzamine, 10 mg orally two or three times daily. Tumors are generally clearly separated from If tachycardia develops, beta-adrenergic blocking the adrenal cortex by a thin band of fibrous tissue. Propranolol should Extension into the cortex or vascular invasion may never be started before alpha blockade because un- occur. Phenoxybenzamine increases the total blood malignant pheochromocytomas is not clear. Ap- only absolute criterion for malignancy is the pres- propriately used calcium channel antagonists and ence of secondary tumors in sites where chromaffin selective alpha1-receptor blockers are also effective cells are not usually present and visceral metastases. Malignant tumors tend to be larger and weigh Small (<6 cm) intra-adrenal pheochromocytomas more. How- Patients with pheochromocytomas can present ever, larger tumors should be removed by open sur- with a range of symptoms, from mild labile hyper- gery. Laparoscopic procedures appear to decrease tension to sudden death secondary to severe hyper- pain and shorten the time to recovery. However, tension, myocardial infarction, or cerebral vascular 346 Case 75 iatrogenic pheochromocytomatosis has been de- 2003;138:424–429. Iatrogenic pheochromocy- tomatosis: a previously unreported result of laparoscopic imaging and biochemical studies because tumors adrenalectomy. A comparison of biochemical tests for pheochromocytoma: measurement of fractionated plasma metanephrines compared with the combination of 24- Suggested Readings hour urinary metanephrines and catecholamines. Similarly, if the pa- tient has evidence of gastric outlet obstruction Presentation from ulcer disease or scarring, a nasogastric tube The patient is a 52-year-old man who has severe epi- should be inserted to reduce gastric antral disten- gastric pain and diarrhea. A secretin test may also be done, in which 2 U/kg of secretin is administered intravenously and serum ■ Endoscopic Image levels of gastrin are obtained prior to secretin and at 1, 5, 10, and 15 minutes later. Antral G-cell hyperplasia should be excluded by measuring serum levels of gastrin before and after a protein meal. The gastrocolic ligament is di- mogranin A are elevated, and this is consistent with vided to expose the lesser sac. The inferior border of the pancreas is mobilized by dividing the inferior attachments so that the pancreas can be palpated with the in- Diagnosis and Recommendation dex finger underneath and the thumb on top. Lymph nodes around the porta hepatis, celiac The diagnosis of sporadic Zollinger-Ellison syn- axis, and head of the pancreas are systematically drome means that there is a gastrin-secreting neu- sampled to document the presence of lymph roendocrine tumor that is causing the severe peptic node metastases or lymph node primary gastri- ulcer disease, diarrhea, and weight loss. Intraoperative ultrasound of the pan- step in management is to control the acid hyper- creas and liver is performed to image tumor secretion with medication and to perform localiz- within either organ. The duodenum is opened to identify gastri- acid output and administer a proton-pump in- nomas within the duodenum, the most common hibitor at doses that normalize the acid secretion. In this patient, a gastri- This typically requires omeprazole at 60 to 80 mg noma is identified within the duodenum and it is every 12 hours. The acid output should be <10 excised with a small rim of normal intestine mEq/h prior to the dose of omeprazole. If the acid output is controlled in this manner, the ■ Intraoperative Image peptic ulcer disease will heal, the diarrhea will stop, and the patient will gain weight.
Moreover buy sildalist 120mg lowest price, systematic teaching of the use of the pump is essential order sildalist with american express, while at the same time the responsible physician should have proven experience with the use of pumps buy discount sildalist 120 mg on-line. Consequently, it is obvious that it is not feasible, as well as not advisable, for all Type 1 diabetics to use pumps. The use of pumps in diabetic children – or even infants – is con- tinuously increasing, since the results of their use are encouraging. Why does hypoglycaemia unawareness constitute an indication for treatment with an insulin pump? Insulin-treated persons, who manifest hypoglycaemia unawareness due to multiple hypoglycaemic episodes in the frame of very strict diabetic control, can correct this complication by setting slightly higher blood sugar targets. Treatment with an insulin pump helps the controlled achievement of these individualized targets. The pump users should maintain basic conditions of hygiene where the catheter end connects to their skin. They should also know about the use of intensiﬁed treatment with insulin injections (in case this is needed), and have batteries and materials for the change of the catheter. A 24-hour telephone service should be available that offers advice or solutions when problems with the use of the pump occur. Local microbial infections at the point of catheter entry, hypoglycaemic or hyperglycaemic episodes and episodes of ketosis can occur if the New therapies in diabetes 415 pump is not used properly or if – and this is infrequent with the newer pumps – technical problems arise. These problems are usually prevented with the right education, the continuous psychological support of the users and regular visits to their physicians. With improvement in pump technology and the provision of more needs of the users in the software, undesirable effects are minimized. Moreover, the increasing interna- tional experience and rich literature gathered by the use of pumps, contribute to the reduction of undesirable effects. They can disconnect the pump for a short period of time of 1–2 hours usually without consequences (for example, when they want to have a bath, etc. If, however, they want to remove it for more time, they should receive extra insulin in order to cover the basal rate. If they do not want to use it for a day or more, they should apply an intensiﬁed regimen with subcutaneous insulin injections on these days. These individuals should communicate with their doctor on an almost daily basis during the ﬁrst weeks, until the blood sugar levels are controlled and there is certainty that the use of the pump and the measurement of the food carbohydrates are being performed correctly. If control is good, the insulin users should repeat their education on the measurement of the food carbohydrates after about one year. Many patients who use an insulin pump feel that after a few months they can control their blood sugar levels without the help of their doctors and so they can omit visits. Some studies support the idea that treatment with pumps has an advantage and other studies show that the two treatments are equivalent. There is, however, a general consensus that the blood glucose ﬂuctuations are smaller with the use of a pump, and the hypoglycaemic episodes are fewer. Moreover, a claimed increase in the percentage of ketoacidotic episodes with pump users, compared to those treated with multiple insulin injections, has not been proven. A lot of small studies agree that quality of life is better when a pump is used, and that microvascular complications occur less often. There is also evidence that diabetic neuropathy is improved with the use of an insulin pump. There is no signiﬁcant evidence that the incidence of macroangiopathy is reduced with the use of a pump compared with multiple insulin injections. Furthermore, the insulin needs are generally less (roughly by 15 percent) when a pump is used compared to multiple injections and some consider this element as a potential advantage for the prevention of atherosclerosis. Apart from the above mentioned conditions, the cost of the pump plays a signiﬁcant role. In some countries, an unwillingness is observed con- cerning the use of pumps that stems from the conviction that their wide- spread application will adversely effect the insurance system. Studies in certain countries, however, have shown that treatment with insulin pumps is ﬁnancially more beneﬁcial, provided it is performed correctly, when the long-term economic beneﬁts of the prevention of late diabetic complications are taken into account. Pro- vided that these individuals are sufﬁciently controlled with an intensive New therapies in diabetes 417 regimen of multiple insulin injections (which is not rare), and are satisﬁed with this treatment, obviously there is no reason to recommend treatment with an insulin pump. Their extent in 2 humans is 50–140 m , and they contain around 500 million alveoli. The perfusion ﬂow is about 5 litres per minute, and the pulmonary capillary blood volume is around 0. Many peptidases are absent, and are infact encountered in the gastro- intestinal tract. The administered insulin does not immediately pass through the liver, unlike insulin physiologically secreted by the pancreas, which is channelled via the portal vein to the liver. Insulin can be inhaled in different forms, depending on how it has been prepared by various companies. Insulin connected to big porous particles, stable in room temperature, which are inhaled with special appliances, from Alkermes and Eli Lilly. There is no consensus on whether dry powder or the solution is abso- rbed better, or is more effective, since there are no comparative studies. Particles of > 10 mm in size remain in the mucosa of the mouth, the pharynx, the larynx and the bronchial tree. Macrophages and peptidases degrade the insulin particles that remain in the alveoli. How does the action of inhaled insulin differ from the action of the subcutaneously administered insulin? The onset of action of the inhaled insulin is more rapid than that of subcutaneously administered rapid-acting regular insulin (but not than the onset of action of the very-rapidly acting insulin analogues). Its action has an intermediate duration between that of the very-rapid acting analogues and the rapid-acting regular insulin. Obviously, the main beneﬁt is the avoidance of injections for the administration of rapid-acting insulin. From clinical studies up to now New therapies in diabetes 419 (which are small and of short duration so far), satisfaction from its use is deﬁnitely higher for patients, compared to the use of subcutaneous insulin. The existing inhalation appliances do not allow for an easy change of the dose of insulin. Only a small percentage (roughly 10 percent of the administered dose) is absorbed, since a quantity of insulin remains in the appliance (in the walls and the chamber), and, as mentioned before, particles smaller than 1 mm and larger than 10 mm are not absorbed. This characteristic renders the treatment with inhaled insulin ten times more expensive than treatment with subcutaneous insulin. The improvement, however, of glycaemic control in patients who refuse to start subcutaneous insulin, may possibly have more economic ben- eﬁt as a whole, due to the expected reduction of chronic diabetic complications. Anti-insulin antibodies develop with the inhalation of insulin in larger proportions compared with the use of subcutaneous insulin, an element without clinical importance (so far).
This was a 3-month study paw-licking and paw-lifting pain behaviors due to formalin buy generic sildalist on line. Patients were randomized to receive single venting peripheral sensitization in a dose-dependent manner discount sildalist 120mgmg visa. Patients receiving 25U onabotulinum toxin A showed a signiﬁcantly Onabotulinum Toxin and Headaches greater reduction in mean headache severity compared with placebo at months 1 and 2 (p<0 best purchase for sildalist. Smuts conducted a 4-month, randomized, double- Onabotulinum toxin A suppression of substance-P release blind, placebo-controlled trial in 37 patients with chronic has been demonstrated in the iris muscles of rabbits  tension-type headache . Onabotulinum toxin A (50U) 15 Onabotulinum Toxin Injection and Headaches 105 treatment resulted in statistically signiﬁcant improvements a clinically signiﬁcant improvement compared with pla- in headache intensity and headache-free days by month 3 cebo in responder rates and headache frequency. The primary efﬁcacy mea- blind, randomized, placebo-controlled multicenter study sure was the mean change from baseline in the frequency by Silberstein and colleagues in 300 patients with chronic of headache-free days for the placebo nonresponder group tension-type headache showed improvement in headaches at day 180. The main secondary measures were the per- by day 60, and, at day 90, more patients in three onabotuli- centage of patients with a decrease from baseline of 50 % num toxin A groups (86–100U) had at least a 50 % decrease or more in the frequency of headache days for the placebo in tension headache days than did patients given placebo nonresponder group at day 180 and the mean change from (p 0. However, the study failed to ﬁnd baseline in the frequency of headaches per 30-day period. Statistically Freitag completed a double-blind, randomized, con- signiﬁcantly more patients treated with onabotulinum toxin trolled trial in 60 chronic migraine sufferers, and patients A had a decrease from baseline of 50 % or greater in the were injected with 100U of onabotulinum toxin A in a ﬁxed- frequency of headache days per 30-day period at day 180 dose–ﬁxed-site technique . After two injection A headache treatment may be related to inconsistencies in sessions, the maximum change in the mean frequency of administration. The number of treatments administered may halved the frequency of headaches from baseline in over also be important. Onabotulinum As a consequence of the above results, onabotulinum toxin A and placebo signiﬁcantly differed in the change from toxin A treatment began to focus around those patients with baseline in headache frequency and headache severity for chronic daily headache. Headache occurs Headaches lasting longer than 4 h were signiﬁcantly more than 15 days per month and is often associated with reduced at most time points throughout the Mathew study considerable disability . The mean frequency of headache of onabotulinum toxin A in 355 patients with chronic daily episodes lasting 4 or more hours was reduced from baseline headache in an 11-month, multicenter trial . An a priori analysis of change from base- than 4 h’ duration was signiﬁcantly greater for onabotulinum line in headache frequency revealed that onabotulinum toxin A at all assessments [53 ]. Patients in the ona- Therapy) involved two multicentered pivotal trials, each botulinum toxin A group had a signiﬁcant reduction in acute included a 24-week randomized, double-blind phase fol- headache pain medication usage at day 90 (onabotulinum lowed by a 32-week open-label phase (ClinicalTrials. Additionally, the number of days with acute (155–195U) administered intramuscularly across seven headache pain medication use was signiﬁcantly reduced at head and neck muscles or placebo injections every 12 weeks several time points, including the primary efﬁcacy date (180 for up to 5 treatment cycles . All of the 168 patients (47 % of the total The two studies had different primary endpoints. Signiﬁcant headache episodes at all time points except for day 90 versus reductions were also present for headache-related disability. At day 180, after 2 treatment cycles, the primary The primary endpoint for the ﬁrst trial was the change efﬁcacy time point, onabotulinum toxin A treatment resulted from baseline in the number of headache episodes at the end in a mean decrease from baseline of 8. Pooled analyses showed number of days with acute headache pain medication ranged a large mean decrease from baseline in frequency of headache from −5. There were botulinum toxin A may be a reasonable option in reducing signiﬁcant differences favoring onabotulinum toxin A for all acute medication overuse and potentially preventing the secondary efﬁcacy variables at all time points, except for the development of medication overuse headache. Adverse toxin A also appears to reduce acute medication in existing events occurred in 62. Porter did a double-blind, randomized, pilot in 3 sites on each side, cervical paraspinals 5 units in 2 sites study in 60 patients . The onabotulinum toxin A-treated on each side, and trapezius muscles 5 units in 3 sites on group received a single injection cycle of up to 200U using each side, and the follow-the-pain sites, temporalis 5 units a combination ﬁxed-site–ﬁxed-dose and follow-the-pain in 2 additional sites, occipitalis 5 units in 2 additional sites, methodology, as well as a blinded placebo tablet twice a and trapezius 5 units in 4 additional sites. The divalproex sodium from 155 units for the ﬁxed sites to a total of 195 units for group received one cycle of saline injections and divalproex the combination of ﬁxed sites and follow-the-pain sites sodium 250 mg twice a day the ﬁrst week and 500 mg twice (Fig. Both groups had statistically signiﬁcant mean improvements from baseline in headache episode fre- quency and mean headache day frequency per month, with Safety and Tolerability no between-group differences. Blumenfeld conducted a similar comparative, random- Onabotulinum toxin A should be used with extreme cau- ized, double-blind trial in 59 patients and found similar tion in patients who have neuromuscular disorders, such as results . This 9-month study evaluated efﬁcacy at 1-, 3-, myasthenia gravis or Lambert–Eaton syndrome. The onabotulinum toxin A group received the potential risk of systemic effects of botulism developing 100U via the follow-the-pain paradigm at months 0 and 3 at sites distant from the injection site. The Botulinum toxins have the potential for antibody forma- divalproex sodium group received saline injections, 250 mg tion. This may be minimized by injecting with the lowest twice a day for the ﬁrst week with the option of 500 mg twice effective dose, with the longest feasible intervals between a day thereafter if necessary. Local weakness of the injected muscles adverse events in the onabotulinum toxin A-treated group may occur, but weakness of adjacent muscles may be due to compared with the divalproex sodium group. Patients should be advised about the reduction a similar study design that compared the efﬁcacy of onabotu- of hyperfunctional facial lines. When injecting the corrugator linum toxin A and topiramate and had similar ﬁndings [61 ]. These adverse events are generally mild to moder- Onabotulinum Toxin Injection Technique ate, temporary, self-resolving, and more common with higher doses. Patients injected for cervical dystonia and spasticity have The standardized method of injecting onabotulinum toxin A developed dysphagia and aspiration pneumonia. The total dose of onabotulinum toxin A is 155U Conclusion in a ﬁxed-dose, ﬁxed-site protocol; an additional 40U can Onabotulinum toxin A relieves headache pain by its mus- be given on an individualized basis, taking into account the cle relaxing, anti-inﬂammatory, and antinociceptive prop- speciﬁc features of each patient, including location of head- erties. Further work is needed to elucidate the exact ache, as well as tender areas in the temporal, occipital, and/ mechanism of action in headache pain. Trapezius: 15 U each side sustained and well-tolerated response to onabotulinum 4. Prophylactic treatment of chronic tension-type headache using botulinum toxin type A. Botulinum toxin type A (Botox) for treatment of migraine headaches: an open-label study. Treatment of chronic cervical-associ- References ated headache with botulinum toxin A: a pilot study. Physiology and pharmacology of therapeutic botulinum A and divalproex sodium for prophylactic treatment of episodic or neurotoxins. Botulinum toxin type A from trigeminal ganglion neurons and relieves neuropathy behav- for treatment of chronic migraine; the double blind phase of the iors induced by infraorbital nerve constriction. Dural stimulation in awake rats: migraine: a safe, well-tolerated, and effective treatment paradigm based a model for recurrent headache. Botulinum toxin type A and other botulinum neurotoxin A on sciatic nerve injury-induced neuroimmunological toxin serotypes; a comparative review of biochemical and pharma- changes in rat dorsal root ganglia and spinal cord. Surgical treatment of migraine head- repair of motor endplates after botulinum neurotoxin type A poison- aches. Differential inhibition by botulinum type A produced from the original bulk toxin source and current neurotoxin A of cotransmitters released from autonomic vasodilator bulk toxin source for the treatment of cervical dystonia. Intramuscular injection of of botulinum toxin type A on capsaicin-evoked pain, ﬂare, and sec- botulinum toxin for the treatment of wrist and ﬁnger spasticity after ondary hyperalgesia in an experimental model of trigeminal sensi- a stroke.
Creatinine is a product of phospho- Aferent arteriolar tone appears to be responsible for creatine breakdown in muscle order sildalist 120 mg amex. It ceases when mean systemic arterial pressure is less preferentially dilates the aferent glomerular arteri- than 40–50 mm Hg order sildalist 120mgmg amex. Neuronal and Paracrine Regulation mechanism is poorly understood buy generic sildalist online, the macula densa Sympathetic outfow from the spinal cord at the level appears to be responsible for tubuloglomerular feed- of T4–L1 reaches the kidneys via the celiac and renal back by inducing refex changes in aferent arteriolar plexuses. Sympathetic nerves innervate the juxtaglo- tone and possibly glomerular capillary permeability. Dopamine 4 Increases in aferent glomerular arteriolar pressure and fenoldopam dilate aferent and eferent stimulate renin release and formation of angiotensin arterioles via D1-receptor activation. Both Fenoldopam and low-dose dopamine infusion can at aferent and eferent glomerular arterioles are con- least partially reverse norepinephrine-induced renal stricted, but because the eferent arteriole is smaller, vasoconstriction. Adrenal catecholamines (epinephrine and cells from circulating L-3,4-dihydroxyphenylalanine norepinephrine) directly and preferentially increase (L-dopa). It occurs in 1–5% of all hospitalized Clinical studies attempting to defne the efects patients and is a major contributor to increased hos- of anesthetic agents on renal function are compli- pital length of stay, markedly increasing morbidity, cated and difcult. Endocrine Endocrine changes during sedation and general anesthesia are a component of the stress response 2. Such changes are usually less pronounced induced by factors that may include anxiety, during regional anesthesia. Increases mediated by autonomic and hormonal in epinephrine and norepinephrine, renin, responses to surgery and anesthesia. The when administered at low fow rates in endocrine response to surgery and anesthesia 6 laboratory animals. Depending on the level Volatile Agents of sympathetic blockade, spinal or epidural anes- Halothane, sevofurane, desfurane, and isofurane thesia may cause a drop in systemic blood pressure decrease renal vascular resistance. As previ- 7 secondary to decreased cardiac output as a result of ously noted, compound A, a breakdown prod- decreased sympathetic tone. Drugs obstruction acyclovir, sulfonamides, ethylene with antidopaminergic activity—such as metoclo- glycol, uric acid, cocaine, lovastatin pramide, phenothiazines, and droperidol—may Immunological– Penicillin, cephalosporins, allopurinol, impair the renal response to dopamine. Mechanisms In addition to the physiological changes associated of injury include vasoconstriction, direct tubular with the neuroendocrine stress response to surgery, injury, drug-induced immunological and infamma- certain surgical procedures can signifcantly alter tory responses, and renal microvascular or tubular renal physiology. In addition to intravenous hydration, produced during laparoscopy creates an pretreatment with N-acetylcysteine (600 mg orally abdominal compartment syndrome–like state. N-Acetylcysteine’s include central venous compression (renal vein and protective action may be due to its free radical vena cava); renal parenchymal compression; scavenging or sulfydryl donor (reducing) prop- decreased cardiac output; and increases in plasma erties. Mannitol appears to activate the intrare- cantly impair renal function include cardiopulmo- nal synthesis of vasodilating prostaglandins. It also nary bypass (see Chapter 22), cross-clamping of the appears to be a free radical scavenger. Injury in High-Risk Patients Many clinicians continue to administer mannitol for renal protection and, less frequently, to convert Diuretics oliguric acute kidney failure to nonoliguric kidney failure, with the goal of lowering associated mor- Diuretics increase urinary output by decreasing + bidity and mortality. Only compared with correction of hypovolemia and major mechanisms will be reviewed here. In The majority of diuretics exert their action on addition, high-dose mannitol can be nephrotoxic, the luminal cell membrane from within the renal especially in patients with renal insufciency. Because nearly all diuretics are highly protein bound, relatively little of the free drug B. Most diuretics Mannitol will augment urinary output in the set- must therefore be secreted by the proximal tubule ting of hypovolemia but will have little efect in the (usually via the organic anion pump) to exert their presence of severe glomerular or tubular injury. Impaired delivery into the renal tubules However, the optimal initial approach to evaluation accounts for resistance to diuretics in patients with of acute oliguria is to correct hypovolemia and opti- impaired renal function. Acute Reduction of Intraocular erulus and undergo limited or no reabsorption in Pressure in the Perioperative Period the proximal tubule. Although Intravenous Dosage their major efect is to increase water excretion, in large doses, osmotically active diuretics also increase The intravenous dose for mannitol is 0. The same mechanism also impairs water and solute reab- Side Eﬀects sorption in the loop of Henle. Mannitol solutions are hypertonic and acutely raise Mannitol is the most commonly used osmotic plasma and extracellular osmolality. It is a six-carbon sugar that normally cellular to extracellular shif of water can transiently undergoes little or no reabsorption. Edematous States (Sodium Overload) hyponatremia and reductions in hemoglobin con- centration are also common and represent acute These disorders include heart failure, cirrhosis, the hemodilution resulting from rapid movement of nephrotic syndrome, and renal insufciency. When water out of cells; a modest, transient increase given intravenously, these agents can rapidly reverse in plasma potassium concentration may also be cardiac and pulmonary manifestations of fuid observed. If fuid and electrolyte losses are not Loop diuretics may be used as adjuncts to other replaced following diuresis, mannitol administra- hypotensive agents, particularly when thiazides tion can result in hypovolemia, hypokalemia, and (below) alone are inefective. As noted above, high-dose mannitol can be nephrotoxic, especially The response to a small dose (10–20 mg) of furo- in patients with renal insufciency. Little or no response is seen with hypovolemia, whereas resumption of normal uri- The loop diuretics include furosemide (Lasix), nary output occurs with the latter. However, the bumetanide (Bumex), ethacrynic acid (Edecrin), optimal initial approach to evaluation of acute oli- and torsemide (Demadex). All loop diuretics inhibit + − guria is to correct hypovolemia and optimize cardiac Na and Cl reabsorption in the thick ascending output and renal perfusion. Sodium reabsorption at that site requires that all four sites on the Na –K + + –2Cl − luminal car- D. Loop diuretics compete − Failure to Nonoliguric Failure with Cl for its binding site on the carrier protein As with mannitol, discussed earlier, many clinicians (see Figure 29–4). With a maximal efect, they can continue to administer loop diuretics for renal pro- promote excretion of 15–20% of the fltered sodium tection and to convert oliguric acute kidney failure load. Both urinary concentrating and urinary dilut- to nonoliguric kidney failure, despite lack of evi- ing capacities are impaired. Treatment of Hypercalcemia marked increase in diuresis may occur when a loop See Chapter 49. Rapid Correction of Hyponatremia Loop diuretics also increase urinary calcium See Chapter 49. Ethacrynic acid is the only loop diuretic that is not a sulfonamide deriv- ative, and thus may be the diuretic of choice in Intravenous Dosages patients allergic to sulfonamide drugs. Torsemide The intravenous doses are furosemide, 10–100 mg; may have an antihypertensive action independent of bumetanide, 0. Hypertension ing tubules increases K+ and H+ secretion at those T iazide and thiazide-like diuretics are ofen selected sites and can result in hypokalemia and metabolic as frst-line agents in the treatment of hyperten- alkalosis. Marked Na+ losses will also lead to hypo- sion (see Chapter 21), and they have been shown to volemia and prerenal azotemia; secondary hyper- improve long-term outcomes in this disorder. Edematous Disorders magnesium loss promoted by loop diuretics may (Sodium Overload) result in hypocalcemia or hypomagnesemia, or These drugs are used to treat mild to moderate both. Hypercalciuria and irreversible hearing loss has been reported T iazide and thiazide-like diuretics are ofen used to with loop diuretics, especially furosemide and decrease calcium excretion in patients with hyper- ethacrynic acid. This group of agents includes thiazides, containing a benzothiadiazine molecular structure, and also Intravenous Dosages thiazide-like drugs with similar actions but without These agents are only given orally. Although thiazide and thiazide-like diuretics deliver Tese diuretics acThat the distal tubule, including less sodium to the collecting tubules than loop the connecting segment, and inhibition of sodium diuretics, the increase in sodium excretion is enough reabsorption at this site impairs diluting but not to enhance K+ secretion and frequently results in concentrating ability.
This same material should be placed under ing approximately 30–35 calories/kg daily and 1 sildalist 120mgmg on-line. Ascorbic acid 500 mg twice daily may enhance healing purchase sildalist on line, after serial surgical debridement can often be controlled with but this has not been proven effective 120mgmg sildalist. Keep in mind that the patient who an alginate dressing; the calcium alginate assists in the clotting is debilitated and has a multitude of other conditions may have pathway. Moistening with saline can loosen an alginate dress- no healing capabilities (skin failure). Increased bacterial burden may impede healing before Obtain total protein, serum albumin clinical signs of infection become apparent. The odor of an Obtain complete blood count infected ulcer can often be eliminated by applying metronida- zole gel to the ulcer bed. Systemic antimicrobial agents are indi- Clinical observation is the key to making the diagnosis. Cuta- cated for patients with bacteremia, sepsis, advancing cellulitis, neous biopsies will not be helpful, although biopsies for aerobic or osteomyelitis. Patients at risk need to be considered in terms of the underly- Blanchable erythema and non-blanchable erythema ing disease process: Spinal cord injury in an otherwise healthy person Blanchable and non-blanchable erythema represent the initial Neurologic disease with no medical disease, but a devastating development of the decubitus ulcer. The early lesions of non- condition such as multiple sclerosis or a cerebral vascular acci- blanchable erythema are bright red; later, they become dark red dent compromising the body integrity to purple. Both can be treated with adherent synthetic dressings to Debilitation with a multitude of medical diseases affecting the protect the lesion from friction and shear, topical corticosteroids, or patient (e. The bright red lesion can also be treated with 2% disease, Alzheimer’s disease, malignancy, malnutrition, and nitroglycerin ointment; 0. Bear in mind that ulcer staging is arbi- emia, serum albumin depletion, anemia, and hypotension. Risk factors associated with pressure ulcer development in critically ill traumatic spinal cord injury patients. Dermatologic observation Wilczweski P, Grimm D, Gianakis A, Gill B, Sarver W, McNett M. Blanchable erythema Clinical variables associated with pressure ulcers were fecal Non-blanchable erythema management systems, incontinence, acidosis, support surfaces, Decubitus dermatitis steroids, and additional equipment with hypotension as the Superfcial ulcer strongest predictor of pressure ulcers in 94 spinal cord injury Deep ulcer patients. Staging Pressure ulcer tissue histology: an appraisal of current Stages are as follows: knowledge. Ostomy Wound Manage 2007; 53: Stage I: non-blanchable erythema of intact skin 40–9. The concept of staging need not be thought of as National Pressure Ulcer Advisory Panel. Results of the national pressure Accumulating evidence suggests that a number of ulcers (most ulcer advisory panel consensus conference. Ostomy Wound Manage 2011; 57: compartment and progress outward to the dermis and epidermis 24–37. In a consensus conference that involved 24 stakeholder organi- By eliminating the current numerical classifcation system and zations from various disciplines, it was unanimously agreed that documenting the partial-thickness and full-thickness depth along pressure ulcers are largely preventable but not always avoidable. Ann value for predicting pressure ulcers in acutely ill veterans than Intern Med 1986; 105: 337–42. Hypoalbuminemia, fecal incontinence, and fractures may iden- tify bedridden patients at greatest risk for developing pressure ulcers. Elimination of pressure C All 40 patients with sacral pressure ulcers showed mild-to- Pressure-reducing and -relieving devices C moderate anemia with low serum iron and normal or increased Removal of necrotic debris C ferritin and hypoproteinemia with albuminemia. Patients who developed fewer pressure sores were those who Dilemmas about the decubitus ulcer: skin-fold ulcerations were turned every 2 to 3 hours. Shearing force as a factor in decubitus ulcers in paraple- Decubitus ulcers continue to have an uncertain etiology. No conclusive evidence on the effects of pressure-relieving Drawsheets for prevention of decubitus ulcer. Decubitus prophylaxis: a prospective trial on the eff- Debridement ciency of alternating-pressure air mattresses and water Collagenase in the treatment of dermal and decubitus mattresses. The incidence of pressure ulcers in patients cared for on the Enzymes can be used alone or in combination with other hospital mattress was signifcantly greater than in patients on forms of debridement. Weight shifting is an effective means of reducing the risk of pressure ulcer formation. J Am Coll Emerg Phys 1976; 5: the supersoft 3-piece mattress on areas of maximum 17–21. Enzymes normally present in wound fuid digest devitalized Mechanical loading and support surfaces. In: Agency for tissue when allowed to collect under a synthetic dressing for Health Care Policy and Research. Debridement of cutaneous ulcer: medical and surgical An overview of pressure-relieving devices. A clinical comparison of two pressure reducing surfaces Debridement can be accomplished by cold steel cutting, by in the management of pressure ulcers. Decubitus chemical application, or by autohemolytic destruction under an 1992; 5: 52–5, 58–60, 62–4. Adv A randomized trial of low-air-loss beds for treatment of Wound Care 1995; 6: 22–44. Patients with pressure ulcers showed a signifcantly improved More effective removal of debris can be accomplished by twice- healing rate. Comparison of total body tissue interface pressure of Maggot debridement therapy of infected ulcers: patient specialized pressure-relieving mattresses. Anderson was not so useful for the elderly who had septic arthritis, chronic C, Rappl L. Evidence to support debridement in enhancing healing is Although vitamins A, B, and C, proteins, and minerals such as scarce, and there are insuffcient data to support debridement zinc and copper promote healing in animal models, supplements for venous ulcers and pressure ulcers. The potential benefts of tube feeding may be lost due to diarrhea, bowel incontinence, and restricted mobility. Topical metronidazole gel: the bacteriology of decubitus A comparison of the effcacy and cost-effectiveness of two ulcers. Clin Dermatol The presence of increasing pain may make infection of a 2007; 25: 33–8. Further evidence is required to deter- There are many occlusive dressings available which are impor- mine which, if any, type of quantitative swab culture is most tant for accelerating wound healing. There are no satisfactory studies available to prove that hyper- High protein with increased caloric contents may enhance baric oxygen is useful in decubitus or arterial ulcers. Langer G, Schloemer G, Knerr A, Kuss O, Pros and cons of various dressing materials, including vacuum- Behrens J.
Drug is dissolved in a low boiling carinic (M3) receptors on bronchial smooth muscle point liquid in a canister under pressure order sildalist paypal. Blockade of these receptors releases a metered dose of liquid that is ejected into the at- with atropine causes bronchodilatation order sildalist online, although the pre- mosphere; the carrier liquid evaporates instantly buy cheap sildalist 120 mg on line, leaving ferred antimuscarinics in clinical practice are inhaled ipra- an aerosol of the drug that is inhaled. This switch has introduced a noticeable change antimuscarinic effects outside of the lung. They are used in the taste of some inhalers, but more importantly it has 475 Section | 5 | Cardiorespiratory and renal systems changed the bio-equivalence of inhaled glucocorticoids. Short-acting b -adrenoceptor agonists are used 2 To ensure optimal drug delivery, it is necessary to coor- throughout as rescue therapy for acute symptoms. Particular attention should be paid to inhaler used between the inhaler and lips; these act as an aerosol technique, as this is an important cause of treatment reservoir and also reduce impaction of aerosol in the oro- failure. Topical deposition can cause local side-effects in even with the addition of a spacer device or use of a dry- the mouth, particularly candida with inhaled glucocorti- powder device, can be given oral therapy, although this coids; a spacer abolishes this problem. Jet nebulisers require a driving gas, usually air from a An inhaled b2-adrenoceptor agonist should be used compressor unit for home use, or oxygen in hospital; the so- initially. Salbutamol or terbutaline (1–2 puffs up to four lution in the nebulising chamber is broken into droplets by times daily) are typical short-acting b2-adrenoceptor ago- the jet and the larger droplets are filtered off leaving the smal- nists whose bronchodilator effect is prompt in onset ler ones to be inhaled. Salmeterol and for- tion into particles of uniform size by vibrations created by moterol have a much longer duration of effect (12–24 h), a piezoelectric crystal (which converts electricity into me- making them useful for nocturnal symptoms; they should chanical vibration). With either method the aerosol is deliv- not be used as ‘rescue’ bronchodilator (salmeterol in partic- ered to the patient by a mouthpiece or facemask, so no ular, because its bronchodilating action takes 15–30 min to coordination is called for, and the dose can be altered by emerge) nor as a replacement for inhaled glucocorticoid changing the strength of the solution. Patients can often sodium cromoglicate or low-dose inhaled glucocorticoid use these when they fail with metered-dose aerosols. The inhaled glucocorticoids in current use Inhalation of powder occasionally causes transient bronchoconstriction. Drug treatment Step 5: Continuous or frequent use of oral This varies with the severity and type of asthma. Neither theophylline, leukotriene antagonist or oral 2 1 the patient’s feelings nor physical examination are alone sufficient to determine whether there is still room for im- Step 3: Add-on long-acting 2 - if no further provement. The scheme starts with a 9British Thoracic Society 2008 Guidelines on the management of asthma. Note that macrolide antibiotics, such as property is important, as it minimises the systemic effects erythromycin and clarithromycin, interfere with theophyl- of inhaled glucocorticoid, 80–90% of which is actually line metabolism. Precisely for this reason, prednisolone or hy- drocortisone would have less advantage (over oral admin- istration) if inhaled, because they are absorbed from the gut Acute severe asthma (‘status asthmaticus’) and enter the circulation with relatively little pre-systemic This is a life-threatening emergency requiring rapid metabolism. The airways may become refractory to lipid solubility and potency than those usually adminis- b2-adrenoceptoragonistsafter36–48 h,partlyforpharmaco- tered orally. Potency (the physical mass of drug in relation logical reasons (possibly receptor desensitisation) and partly to its effect, see p. Themucousplugs, isons of oral drugs, but is essential for locally administered whicharethehallmarkofthecondition,mayalsopreventin- drugs. The following lists, with some explanation, the recom- Inhaled glucocorticoids are generally safe at low doses. High doses (>2000 micrograms/day) are reported to carry a slightly in- Immediate treatment creased risk of cataract and glaucoma; this may reflect local Oxygen by mask (humidified, to help liquefy mucus). Bone Carbon dioxide narcosis is rare in asthma and 60% can turnover is also increased in adults, suggesting a long-term be used if the diagnosis is not in doubt. In older patients, risk of accelerated osteoporosis, and bone growth may be or when there is any concern about chronic carbon reduced in children (although evidence indicates that nor- dioxide retention, start with 28% oxygen and check that mal adult height can be attained10). Terbutaline 5–10 mg Oral prednisolone is very effective for severe exacerba- is an alternative. When oral glucocorti- • Chest radiography is required to exclude coids are used long term (Step 5), doses should be adjusted pneumothorax. Some patients may get further prednisolone-sparing • Alert the intensive care unit. If the patient is improving, twice daily or fluticasone 500 micrograms twice daily. Chest infections in asthma • Prednisolone 30–60 mg daily or hydrocortisone Antimicrobials are over-prescribed for exacerbations of 100–200 mg 6-hourly. Respiratory tract infections do cause increased air- • Nebulised salbutamol or terbutaline 4-hourly. The British Thoracic Society guideline no longer recommends intravenous aminophylline without consultation with a senior 10Agertoft L,Pedersen S2000 Effect of long-term treatmentwith inhaled physician. Doubtless, this reflects an equal lack of evidence base for budesonide on adult height in children with asthma. New England benefit and the very clear potential for harm if given to patients Journal of Medicine 343:1064–1069. Though the relationship between the use of b2- • Give nebulised b -adrenoceptor agonist more receptor agonists and death is presumed to be causal, the 2 frequently, e. In the mid-1960s, there was an epidemic of sudden deaths in young asthmatics outside hospital. It was associated with 13Crane J, Pearce N, Flatt A et al 1989 Prescribed fenoterol and death the introduction of a high-dose, metered aerosol of from asthma in New Zealand: case control study. This strategy is and histamine, and by reversible obstruction of the designed to reduce the frequency of disease exacerbations airways. Quitting smoking direct bronchodilatation by stimulation of the remains the only action of proven benefit in preserving bronchial b2-adrenoceptors. It is indicated when: • Antihistamines conventionally refer to antagonists • PaO2 is less than 7. Drugs that mechanisms by which the haemostatic system maintains modulate the haemostatic system are valuable in the man- blood in a fluid state within vessels yet forms a solid plug agement of bleeding and thrombotic disorders. Drugs are when a vessel is breached, and of the ways in which these classified according to the component of the system they processes may be altered by drugs to prevent or reverse affect and their perceived primary mode of action. In response to en- leading to thrombin generation and clot formation dothelial damage, there is rapid molecular switching to (Fig. Regulation of the haemostatic network in such a way results in localised thrombus formation with 1Genetically controlled by an active promoter and constantly produced minimal loss of vascular patency. Bile is required for the absorption of the natural forms of vitamin K, which are fat soluble. The vitamin allows g- carboxylation of glutamic acid residues in their structure; Fibrinogen Fibrin this permits calcium to bind to the molecule, mediating the conformational change required for enzymatic activity, Fig. Subsequently vitamin K epoxide reductase undergo regulation and modulation during the thrombin converts oxidised vitamin K back to the active vitamin K, generation process itself. The initial thrombin activity is necessary to prime dimensional configuration and associated membrane- the system for a full thrombin explosion.
A chest X-ray is normal order sildalist 120 mg line, without signs of cardiac overload or inﬂammatory inﬁltrates order sildalist 120 mg mastercard. Given the history of metformin ingestion and the presence of metabolic acidosis with a high anion gap order sildalist 120 mg without a prescription, lactate levels are measured in the blood and found to be 6. Metformin is discontinued and the patient started on insulin treatment with a twice a day injection of medium duration insulin. It occurs more frequently in diabetic persons, is a serious condition and often fatal. Type A lactic acidosis is characterized by severe tissue hypoxia (as, for example, in states of shock). Type B lactic acidosis is not characterized by tissue hypoxia (the case under discussion above) and is seen in diabetes, renal and hepatic insufﬁciency, leukaemia, vitamin B12 and B1 deﬁciency, as well as in starvation. Furthermore, the cause can sometimes be medicines, such as fenfor- min, isoniazid, salicylates, methanol and ethylene alcohol. Fre- quently, however, manifestation of lactic acidosis requires the additional presence of some other disease or condition, such as renal failure, cardiopulmonary insufﬁciency, hepatic insufﬁciency, serious infections, severe anaemia, alcoholism, surgeries or shock. Lactic acidosis is a dangerous condition and requires correction of the microcirculatory abnormalities, dealing with the aetiologic factors, treatment of the possibly coexistent infection or other aetiologic factor, and judicious administration of bicarbonate with the intent to raise pH above 7. Thus, alternatively, the use of Carbicarb has been proposed (a mixture of sodium bicarbonate and sodium carbonate). In resistant cases dichloroxic acid is administered (decreases lactate production), although its usefulness is questionable. Often, in severe and dangerous cases of lactic acidosis due to biguanide administration, haemodialysis helps in the removal of the biguanide. It should be emphasized that metformin administration is contraindicated when plasma creatinine concentration is > 1. In elderly people though, it is useful, despite the seemingly normal plasma creatinine concentrations, to calculate creatinine clearance using the Cockroft formula: ð140 À ageÞÂbody weight ðkgÞ Creatinine clearance ðml/minÞ¼ plasma creatinine ðmg/dlÞÂ72 In women this should be multiplied by 0. For the woman under discussion, who weighed 60 kg, calculating her creatinine clearance in this way found it to be 52 ml/min, which represents a moderate degree of renal impairment (despite a normal plasma creatinine level). Therefore, when we intend to prescribe metformin in elderly persons, it is prudent to calculate creatinine clearance with this simple formula and avoid its prescription when values are < 60 ml/min. He was examined by the urologist and had an ultra- sound examination of the kidneys, ureter and prostate. A signiﬁcant hypertrophy of the prostate gland was found, accompanied by an appreciable amount of residual urine in the bladder after urination. The urologist refers the patient back to his primary physician, so that pre-operative instructions for optimal control of his blood glucose before surgery are given. Can the patient be directly operated on, and if yes, should he be admitted to the hospital before the surgery? It is estimated that about 50 percent of diabetic patients will need to undergo at least one surgical procedure during their lifetime. Hyperglycaemia during the Diabetes in Clinical Practice: Questions and Answers from Case Studies. The most common complications of diabetic patients during surgery, anaesthesia and in the post-operative period are as follows: Metabolic: Diabetic ketoacidosis Hyperosmolar coma Hypoglycaemia Electrolyte disturbances (frequently hyperkalaemia or hypokalaemia) Cardiovascular: Hypotension (associated with diabetic neuropathy) Postoperative infarction Thrombotic phenomena Arrhythmias Renal: Acute renal failure Fluid overload Infections What does the preoperative evaluation of this patient include? The preoperative evaluation of a diabetic patient includes evaluation of his cardiac, renal and respiratory function, as is the case with all patients anyway, as well as management of possible anaemia. Cardiac examination is very important because it is well known that, very frequently, coronary heart disease in diabetic people is ‘silent’. Surgery in diabetes 95 Furthermore, the presence of cardiovascular autonomic neuropathy signiﬁcantly increases the risk of vascular complications and should be diagnosed preoperatively. Patients with well-controlled arterial hypertension can undergo a surgical procedure without excess risk. If b-adrenergic blockers are used in the patient’s regimen, he or she can have hypoglycaemia without warning symptoms, and so should be closely monitored. Unless there are contraindications, they should be treated prophylactically with low- molecular-weight heparin subcutaneously and elastic stockings during surgery and postoperatively. The use of vasoactive agents to treat the hypotension that frequently accompanies large decreases of intravascular volume or sepsis, causes severe peripheral vasoconstriction. Patients with underlying poor peripheral perfusion (for example, those with non-palpable peripheral pulses) can develop critical ischaemia or even gangrene with the use of such agents. Plasma creatinine measurement is not enough, because it increases only in advanced stages of diabetic nephropathy. Measurement or calculation of creatinine clearance is recommended (with 24-hour urine collection or the Cockroft formula) as well as measurement of 24-hour urine protein excretion. Pursuit of the presence of microalbuminuria is essential, when the above results are normal. Renal function evaluation is very important because patients with impaired renal function are at higher risk for acute renal failure. Nephrotoxic agents should be avoided in these people (intravenous dye, aminoglycoside antibiotics, etc. Albuminuria is known to increase cardiovascular mortality in these people, and so they should be closely monitored and cared for. Neurologic evaluation Diabetic sufferers can possibly have impaired gastrointestinal motility, which increases the risk of aspirations and also delays onset of patient feeding postoperatively. The doctor should be aware of the presence of gastrointestinal and bladder dysfunction, and so should exert extreme diligence in monitoring ﬂuid balance and using medicines that affect them during surgery. The anaesthesiologist should be aware of the possible presence of orthostatic hypotension (which is commonly associated with neuropa- thy), so that he or she can predict possible haemodynamic alterations during anaesthesia. During anaesthesia and surgery a series of hormonal changes (as a response to stress) can signiﬁcantly affect the diabetic patient’s metabolic control. The most important changes are: increased secretion of compensatory hormones (they promote hepatic glucose production and decreased clearance of glucose from periph- eral tissues); decreased secretion of insulin; decreased activity of insulin (increased insulin resistance). These alterations result in hyperglycaemia, ketosis and increase in metabolic rate and catabolism of the body. General principles for achieving metabolic control in diabetic patients who are going to be operated on are as follows: 1. Metabolic control should be evaluated and its improvement opti- mized on an outpatient basis for non-urgent surgeries. This dehydration is accompanied by electrolyte abnormalities and low intravascular volume, which lead to haemodynamic instability. If the patient is treated with metformin or sulfonylureas, they are discontinued at noon of the previous day before the operation. If it is a minor surgery (as was the case described above) the usual diet and treatment is followed. If the patient is already in the hospital, blood glucose is measured every 4–6 hours and insulin is administered subcutaneously based on an empiric sliding scale, on condition that after insulin administration small meals are offered, mainly containing carbohydrates. The authors of the present book frequently use continuous intravenous infusion of a glucose solution 5 percent (more rarely 10 percent) with the necessary electrolytes, depending on each patient’s needs.