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By D. Mason. Western Maryland College.

Note: the grade system has also been assigned in an effort to parallel an approach more commonly used to evaluate therapeutic recommendations cheap prednisone 5 mg with visa. Randomized trials and systematic reviews have directed decision- making in the use of therapeutic apheresis as a treatment modality (Table 96 buy 20 mg prednisone overnight delivery. Two randomized controlled trials in adults using either continuous plasma filtration versus supportive care [39] or plasma exchange versus standard care [40] have been published 5mg prednisone overnight delivery. No differences were observed in the 14-day mortality rates of 14 patients with sepsis syndrome receiving 34 hours of continuous plasma filtration and 16 untreated control patients (57% vs. When differences between the control and experimental groups were considered using multiple logistic regression, the significance of the treatment variable on mortality was p = 0. A recent meta-analysis of these two trials demonstrated insufficient evidence to recommend plasma exchange as an adjunctive therapy for patients with sepsis or septic shock [41]. No overall difference in mortality was observed between treated patients and an untreated historical control group (42% vs. Although encouraging, these data must be supported by results from additional well-designed randomized controlled trials before plasma exchange can be recommended as a noninvestigational therapy for this indication [41,43]. The evidence supporting a potential benefit of plasma exchange derives from retrospective and case–control studies among more severely affected patients [45,46], whereas randomized controlled trials have yielded supportive results in some studies [47] but not others [48,49] (see Table 96. Because automated red cell exchange (also called erythrocytapheresis) can more rapidly reduce the level of hemoglobin S-positive cells (to the goal of <30%) [5]. Although maintaining euvolemia and minimizing hyperviscosity complications, this modality has been utilized in preference to simple transfusion by many centers. Although this makes intuitive sense, the data needed to show a clear advantage of automated red cell exchange over simple transfusion are lacking. Red cell exchange may also be useful in patients with severe clinical manifestations of falciparum malaria or babesiosis [55]. Although a meta- analysis performed in 2002 showed no survival benefit of red cell exchange compared with antimalarials and aggressive supportive care alone [56], many case reports and series suggest a benefit in clinical status with rapid reduction of hyperparasitemia using adjunctive manual or automated red cell exchange [57–59]. They now no longer recommend its use based on a review of the published literature that found no evidence of overall survival benefit for exchange transfusion as adjunctive therapy [61]. As in fulminant malaria, several case reports demonstrate that patients with overwhelming parasitemia from Babesia also quickly respond to red cell exchange [63]. Automated red cell exchange may be considered as an alternative to large volume phlebotomy in selected patients with uncontrolled erythrocytosis and polycythemia vera with acute thromboembolism, severe microvascular complications, or bleeding [64]. This method can quickly and more safely normalize the hematocrit in patients who are hemodynamically unstable. Signs and symptoms typically manifest as neurologic alterations (confusion, mental status changes, altered level of consciousness) or pulmonary compromise (hypoxemia, diffuse lung infiltrates). The potential benefits of urgent leukapheresis should be discussed with the apheresis physician; however, definitive treatment with chemotherapy should not be delayed by the leukapheresis procedure and is required to prevent the rapid reaccumulation of blasts. Plateletpheresis Plateletpheresis should be considered as an urgent intervention in patients experiencing thrombosis or hemorrhage in the setting of uncontrolled thrombocytosis associated with a stem cell disorder [69]. Such stem cell disorders include essential thrombocythemia, polycythemia vera, idiopathic myelofibrosis, chronic myeloid leukemia, or unclassified myeloproliferative neoplasm. The goal of plateletpheresis is to decrease the platelet count (ideally below 600,000 per µL) and to maintain the count until pharmacologic cytoreductive therapy takes effect [5]. Plateletpheresis may also be electively considered for the prevention of perioperative thrombohemorrhagic complications in patients with myeloproliferative neoplasms undergoing splenectomy [70]. Initial discussion with the apheresis physician will include whether the indication is urgent or routine, the impact of apheresis on other treatment modalities, volume management, fluid replacement, and vascular access. Ongoing discussions should continue through the patient’s course so that appropriate adjustments can be made to optimize the therapy. Schwartz J, Padmanabhan A, Aqui N, et al: Guidelines on the use of therapeutic apheresis in clinical practice-evidence-based approach from the Writing Committee of the American Society for Apheresis: the seventh special issue. Weinstein R: Prevention of citrate reactions during therapeutic plasma exchange by constant infusion of calcium gluconate with the return fluid. Use of cellular and plasma apheresis in the critically ill patient: part 1: technical and physiological considerations. How we developed and use the American Society for Apheresis guidelines for therapeutic apheresis procedures. Evidence-based guideline update: plasmapheresis in neurologic disorders: report of the Therapeutics and Technology Assessment Subcommittee of the American Academy of Neurology. A randomized and controlled study comparing immunoadsorption and plasma exchange in myasthenic crisis. Gajdos P, Chevret S, Clair B, et al: Clinical trial of plasma exchange and high-dose intravenous immunoglobulin in myasthenia gravis. Walsh M, Catapano F, Szpirt W, et al: Plasma exchange for renal vasculitis and idiopathic rapidly progressive glomerulonephritis: a meta-analysis. Busund R, Koukline V, Utrobin U, et al: Plasmapheresis in severe sepsis and septic shock: a prospective, randomized, controlled trial. Walsh M, Catapano F, Szpirt W, et al: Plasma exchange for renal vasculitis and idiopathic rapidly progressive glomerulonephritis: a meta-analysis. Zauner I, Bach D, Braun N, et al: Predictive value of initial histology and effect of plasmapheresis on long-term prognosis of rapidly progressive glomerulonephritis. Cole E, Cattran D, Magil A, et al: A prospective randomized trial of plasma exchange as additive therapy in idiopathic crescentic glomerulonephritis. Boga C, Kozanoglu I, Ozdogu H, et al: Plasma exchange in critically ill patients with sickle cell disease. Out with the bad and in with the good; red cell exchange, white cell reduction, and platelet reduction. American society for apheresis guidelines support use of red cell exchange transfusion for severe malaria with high parasitemia. Bug G, Anargyrou K, Tonn T, et al: Impact of leukapheresis on early death rate in adult acute myeloid leukemia presenting with hyperleukocytosis. Leukapheresis and low-dose chemotherapy do not reduce early mortality in acute myeloid leukemia hyperleukocytosis: a systematic review and meta-analysis. Outcomes and lessons from 3 decades of splenectomy for myelofibrosis with myeloid metaplasia at the Mayo Clinic. Every attempt has been made to be as evidence based as possible, within the intrinsic limitations of the medical toxicology literature. Because overdose studies cannot ethically be performed in humans and animal data may not be available or applicable to humans, predicting the severity of poisoning must be based on toxicodynamic data from previously published reports of human poisonings. However, such data are often incomplete or altogether unavailable and are always limited by the accuracy of the overdose history. Poisoning or intoxication is defined as the occurrence of harmful effects resulting from exposure to a foreign chemical or xenobiotic. In the absence of signs or symptoms, external or internal body contact with a potentially harmful amount of a chemical is merely an exposure. Whether an exposure or overdose results in poisoning depends more on the conditions of exposure (primarily the dose) than the identity of the agent involved. Ordinarily safe chemicals, even those essential for life such as oxygen and water, in excessive amounts or by an inappropriate route can result in harmful effects. Poisoning is distinguished from adverse allergic, intolerance, and idiosyncratic pharmacogenetic reactions in that effects are concentration or dose related and, hence, predictable.

Treatment with intravenous ampicillin–sulbactam 5 mg prednisone fast delivery, ticarcillin–clavulanate prednisone 5mg mastercard, or cefoxitin is usually effective buy prednisone 5mg. As noted for animal bites, the duration of therapy depends on the rate of improvement, the degree of soft tissue damage, and the likelihood of bone involvement. In closed-fist injuries, bone and tendon involvement is common and usually warrants more prolonged antibiotic therapy for presumed osteomyelitis. Narrative review: tetanus-a health threat after natural disasters in developing countries. Guidelines for the management of partial-thickness burns in a general hospital or community setting—recommendations of a European working party. Assessing the relationship between the use of nonsteroidal antiinflammatory drugs and necrotizing fasciitis caused by group A streptococcus. Effect of silver on burn wound infection control and healing: review of the literature. Microbiologic characterization and antimicrobial susceptibility of Clostridium tetani isolated from wounds of patients with clinically diagnosed tetanus. Increasing incidence of necrotizing fasciitis in New Zealand: a nationwide study over the period 1990 to 2006. Fatal toxic shock syndrome associated with Clostridium sordellii after medical abortion. American Burn Association consensus conference to define sepsis and infection in burns. Clinical practice guidelines by the infectious diseases society of America for the treatment of methicillin-resistant Staphylococcus aureus infections in adults and children. A predictive model of recurrent lower extremity cellulitis in a population-based cohort. Successful management of severe group A streptococcal soft tissue infections using an aggressive medical regimen including intravenous polyspecific immunoglobulin together with a conservative surgical approach. Practice guidelines for the diagnosis and management of skin and soft-tissue infections. Necrotizing fasciitis: clinical presentation, microbiology, and determinants of mortality. Are oral antibiotics ever the appropriate treatment for osteomyelitis or septic arthritis? Osteomyelitis is a progressive infectious process that can involve one or multiple components of bone, including the periosteum, medullary cavity, and cortical bone. The disease is characterized by progressive inflammatory destruction of bone, by necrosis, and by new bone formation. Acute Versus Chronic Osteomyelitis Acute osteomyelitis evolves over several days to weeks; chronic osteomyelitis is a disease characterized by clinical symptoms that persist for several weeks. Chronic osteomyelitis can also evolve over months or even years and is characterized by the persistence of microorganisms, by low- grade inflammation, by the presence of necrotic bone (sequestra) or foreign material (or both), and by fistulous tracts. The terms “acute” and “chronic” do not have a sharp demarcation, and they are often used somewhat loosely. Nevertheless, they are useful clinical concepts in infectious disease, because they describe two different patterns of the same disease, often caused by the same microorganisms but with different rates of progression. Initial infections are the result of traumatic injury, penetrating injury, orthopedic surgery, or diabetic or other forms of ischemic or neuropathic ulcer. Classification by extent of bone involvement, four stages: a) medullary, b) superficial, c) localized, and d) diffuse Osteomyelitis of Hematogenous Origin or Attributable to a Contiguous Focus of Infection Hematogenous osteomyelitis is the result of bacteremic spread with seeding of bacteria in bone. Osteomyelitis secondary to a contiguous focus of infection follows trauma, perforation, or an orthopedic procedure. As the name implies, infection first begins in an area adjacent to bone, eventually spreading to the bone. An important category of osteomyelitis resulting from contiguous spread is found in diabetic patients. Classification by Extent of Bone Involvement A second way of classifying osteomyelitis is by the extent of bone involvement. This classification guides the appropriate therapy and also predicts the eventual prognosis. Stage 1 usually can be managed with antibiotics alone, while stages 2-4 require surgical intervention as well as systemic antibiotics: the four stages of osteomyelitis are as follows: 1. Hematogenous osteomyelitis and infected intramedullary rods most commonly result in this stage of involvement. Localized—A discrete area of bone infection that extends to the full thickness of the bone and contains cortical sequestration that can be surgically removed without impairing bony stability. Diffuse—Infection involving all regions of the bone and requires resection to arrest the spread of infection. In adults, hematogenous osteomyelitis most frequently involves the vertebral bodies. In the case of the long bones, bacteria tend to lodge in small end vessels that form sharp loops near the epiphyses. In the case of vertebral bodies, small arteriolar vessels are thought to trap bacteria. The vertebral arteries usually bifurcate and supply two adjacent vertebral bodies, explaining why hematogenous vertebral osteomyelitis usually involves two adjacent boney segments and the intervening disc. In addition, the vertebra is surrounded by a plexus of veins lacking valves, called Batson’s plexus. This venous system drains the bladder and pelvic region and, on occasion, can also transmit infection from the genitourinary tract to the vertebral bodies. The lumbar segments are most commonly infected, followed by the thoracic regions; the cervical region is only occasionally involved. Microbiology the bacteria responsible for hematogenous osteomyelitis essentially reflect their bacteremic incidence as a function of host age, so the organisms most frequently encountered in neonates include Escherichia coli, group B streptococci, and Staphylococcus aureus. The microbiology of Osteomyelitis In elderly people, who are frequently subject to gram-negative bacteremias, an increased incidence of vertebral osteomyelitis attributable to gram-negative rods is found. Fungal osteomyelitis is a complication of intravenous device infections, neutropenia, or profound immune deficiency. Pseudomonas aeruginosa hematogenous osteomyelitis is often seen in intravenous drug abusers, and this organism has a predilection for the cervical vertebrae. Several days after her catheterization, she noted a fever that lasted for 2-3 days. Approximately 3 weeks after her catheterization, she began experiencing dull pain in the lumbosacral region that progressively worsened over the next 2 months. Pain was not relieved by over-the-counter pain medications, and it became so severe that she sought medical attention in the emergency room.

Although it is in small allergic disorders later on in life quantities buy discount prednisone 10 mg line, it is sufficient to meet the needs of the newborn • Breastfeeding enhances brain development discount 40 mg prednisone free shipping, visual baby discount prednisone 40mg with visa. This helps to as breastfed infants get ill less often prevent the baby from developing allergies and intolerance • Breastfeeding protects the environment. Colostrum helps to clean baby’s intestine which is important to prevent jaundice in the newborn. Infant formula, which is generally used as an artificial substitute for human breast milk, is time consuming, less nutritious and Transitional Milk expensive. It is also fraught with innumerable risks for the During the transition from colostrum to the mature milk, infants and children in comparison with the breastfeeding. Science of Milk Transfer Mature milk Understanding the structure of breast and the process of After a few days, colostrum changes into mature milk. Foremilk is produced in larger amounts, and it the human breast consists of the nipple and areola, provides plenty of protein, lactose and other nutrients. The nipple is the area from which the whiter milk that is produced later in a feed. When a baby suckles at the breast, sensory • Increased risk of acute respiratory infections, diarrhea, otitis media and impulses go from the nipple to the brain. In response, the ear infections • Increased risk of necrotizing enterocolitis anterior part of the pituitary gland at the base of the brain • Increased risk of asthma and other allergies secretes prolactin. Prolactin goes in the blood to the breast • Reduced cognitive development and makes the milk secreting cells produce milk. This process • Increased risk of chronic diseases like type 1 diabetes, ulcerative colitis is known as the prolactin reflex. This is evident and Crohn’s disease that milk production is dependent on the suckling stimulus. More prolactin is produced at night due to the inhibition of dopaminergic drive during sleep so breastfeeding at night is especially helpful for keeping up the milk supply. Prolactin suppresses ovulation so breastfeeding can help to delay a new pregnancy. Flow of Breast Milk When a baby suckles, sensory impulses go from the nipple to the brain. In response, the posterior part of the pituitary gland at the base of the brain secretes the hormone oxytocin. Oxytocin goes in the blood to the breast and makes the muscle cells around the alveoli contract. This makes the milk which has collected in the alveoli flow along the ducts toward nipple. Infant and Young Child Feeding: Model Chapter for Textbooks for Medical Students and Allied Health Professionals. The nerve endings in the nipple are important to provide stimulus for the hormonal reflexes important for production and release of the milk from breast. The milk ducts beneath the areola are filled with milk and become wider during a feed. Areola is an important anatomical landmark as it is important to ensure that majority of areola is in baby’s mouth during the feed to achieve an effective suckling. The mammary tissue is composed of alveoli, which are small sacs, made up of millions of milk secreting cells. Milk produced in the alveoli is carried toward the nipple via tubular structures called ducts. Infant and Young Child Feeding: Model Chapter for by myoepithelial tissue which helps in pushing the milk Textbooks for Medical Students and Allied Health Professionals. However, for a good attachment on breast, some basic principle need to be observed for relative positioning of the baby while breastfeeding. These are: • Baby turned towards mother and his or her ears, shoulder and buttock are in a straight line • His face should face the breast with nose opposite the nipple • Mother should hold the baby close to her • In a newborn, she should support his bottom with hand and not just his head and shoulders. Infant and Young Child Feeding: Model Chapter for Textbooks for Medical Students and Allied Health Professionals. Oxytocin • With her thumb pressing on the top of the breast so that can start working before a baby suckles, when a mother it is easier for her baby to attach well. The oxytocin reflex is positively affected the mother should be explained how to bring the baby by mother’s sensations and feelings like thinking lovingly to the breast: about the baby; touching, smelling or seeing the baby; or • Touch baby’s lips with her nipple hearing the baby cry. If the oxytocin reflex does not work • Wait until baby’s mouth is wide open well, the baby may have difficulty in getting the milk. This may happen if the mother is emotionally disturbed or experiencing pain and discomfort. In such a condition, Attachment mother needs support to make her physically and/or emotionally comfortable to make the oxytocin reflex This is important how baby’s mouth is attached to mother’s work again and let the milk flow. In good Signs of an active oxytocin reflex are a tingling suckling position, baby is suckling with nipple and a larger sensation in the breast before or during a feed, milk breast tissue having in his or her mouth. In poor suckling flowing from breasts when mother thinks of the baby or position, baby is suckling with nipple only or nipple with a hears him/her crying, milk flowing from the other breast small breast tissue in his or her mouth. However, • the baby’s chin touches the breast absence of these signs does not indicate an inadequate • His mouth is wide open oxytocin reflex. Breast Milk Inhibitor Breast milk production is also controlled within the breast itself. Sometimes one breast stops making milk, while the other breast continues to make milk although oxytocin and prolactin go equally to both breasts. If a lot of milk is left in a breast, the inhibitor stops the cells from ure 4. If breast milk is removed by suckling with permission from World Health Organization. Infant and Young Child or expression, the inhibitor is also removed and the breast Feeding: Model Chapter for Textbooks for Medical Students and Allied 122 makes more milk. Infant and Young Child Feeding: Model Chapter for Textbooks for services to enable mothers to breastfeed babies for the Medical Students and Allied Health Professionals”. It aims at improving the care of pregnant women, mothers and newborns at health facilities that • His lower lip is turned outwards provide maternity services for protecting, promoting and • One can see more of the areola above his or her mouth supporting breastfeeding. The initiative has measurable and proven impact, increasing the likelihood of babies Poor attachment may lead to pain and damage to being exclusively breastfed for the first 6 months. It may also lead to engorgement of the breast due Components of Baby-Friendly Hospital Initiative to improper milk removal. The baby remains hungry and A maternity facility can be designated “baby-friendly” when frustrated that leads to refusal to suck. Common causes of poor attachment are use of feeding bottle, inexperience of Breastfeeding the Preterm Babies mother and lack of skilled support. The nutritional management plays a large role in the Practices for Successful Breastfeeding immediate survival and subsequent growth, and develop- ment of the preterm infants. The optimal diet for premature To ensure adequate milk production and flow for 6 months infants should support growth at intrauterine rates without of exclusive breastfeeding and thereafter continued imposing stress on the infant’s immature metabolic and breastfeeding, certain practices are very important. Restricting length of the breastfeeding session communicated to all health care staff.

When chest percussion with postural drainage is added to the previously mentioned expansion techniques for patients without prior lung disease cheap prednisone 10 mg on-line, it has failed to affect the incidence of postoperative pulmonary complications [62] best 40 mg prednisone. Augmentation of Mucociliary Clearance Mucociliary clearance is one of the most important defense mechanisms of the respiratory system discount prednisone 10mg without prescription. Mucociliary dysfunction is any defect in the ciliary and secretory elements of mucociliary interaction that disturbs the normal defenses of the airway epithelium [64]. Mucociliary clearance may be ineffective because of depression of the clearance mechanisms or oversecretion in the face of normal mucous transport, or both. Mucus is ineffectively cleared and overproduced by smokers with or without chronic bronchitis and by asthmatic patients [3]. The most important consideration for improving mucociliary clearance is to remove the inciting cause(s) of ineffective clearance and overproduction of secretions. Numerous drugs with potential mucociliary effect have been studied, but only a few are clinically useful. In a randomized controlled trail, healthy volunteers and patients with mild asthma showed no improvement of mucociliary clearance when given inhaled furosemide [65]. In vitro studies have demonstrated that corticosteroids reduce mucous secretion from human airway cells [66], and the use of inhaled corticosteroids has been recommended for the management of bronchorrhea (i. However, we know of no randomized controlled trials demonstrating the benefit of inhaled corticosteroids in the management of bronchorrhea. The flutter mucus clearance device is a small, handheld, pipe-like device used to facilitate the removal of mucus from the lungs. As patients exhale through the device, a steel ball rolls and bounces, producing vibrations that are transmitted throughout the airways. It is postulated that vibrations of the airways intermittently increase endobronchial pressure and accelerate expiratory airflow, thereby enhancing mucus clearance [70]. Among the therapies compared, the volume of sputum was three times greater with the flutter treatment. This, combined with “huff”2 coughing, allows mobilization of peripherally located secretions upward into larger airways. Mechanical insufflation– exsufflation (cough in-exsufflator) increases the volume inhaled during the inspiratory phase of cough, thereby increasing cough effectiveness [63]. Cough efficiency can be further enhanced by applying negative airway pressure for 1 to 3 seconds after the initial inspiration. This method appears to be most beneficial for patients with impaired cough due to neuromuscular disease [75]. In summary, the data available, although not abundant, indicate that in patients with copious secretions, clearance of secretions can be enhanced with selected physical therapy procedures. Although these modalities appear to increase expectoration of mucus, it is not clear what clinical benefit this achieves. There is no information about the influence of physical therapy maneuvers on health care outcomes, including frequency of hospitalization, hospital length of stay, longevity, and quality of life. Although mechanical aspiration or suctioning is routine in most hospitals, many are unaware of the numerous potential complications associated with suctioning, such as tissue trauma, laryngospasm, bronchospasm, hypoxemia, cardiac arrhythmias, respiratory arrest, cardiac arrest, atelectasis, pneumonia, misdirection of catheter, and death [3]. Complications are generally avoidable or reversible if proper technique and indications are adhered to strictly. Routine suctioning according to a predetermined schedule may cause excessive mucosal tissue damage, excessive impairment of mucociliary clearance, unnecessary exposure to the potential risks of hypoxemia associated with the procedure, arrhythmias, atelectasis, and bronchoconstriction [3]. Endotracheal suctioning is indicated when there is a need to (a) remove accumulated secretions, (b) obtain a sputum specimen for microbiologic or cytologic examination, (c) maintain the patency and integrity of the artificial airway, and (d) stimulate cough in patients with ineffective cough [76]. Suction catheters are generally 22 inches long (adequate in length to reach the main stem bronchus) and sized in French units. To avoid obstruction of the artificial airway, the outer diameter of the suction catheter should be less than half the size of the internal diameter of the endotracheal tube (rule of thumb: multiply the inner diameter of the endotracheal tube by 2 and use next smallest size [e. For patients receiving ventilatory support, closed, multiuse systems that are incorporated into the ventilator circuit are available. The practice of instilling normal saline into the airway before suctioning to aid secretion removal is common, but it is unclear whether it is effective and it may increase the risk of nosocomial pneumonia. Although nasotracheal suctioning may be considered for patients who do not have an artificial tracheal airway, it is not recommended because of the potential side effects, and there are other, safer alternatives. Nasotracheal suctioning has been associated with fatal cardiac arrest, life-threatening arrhythmias presumably due to hypoxemia, and bacteremia [3]. Because quantitative cultures acquired with plugged telescoping catheters at bronchoscopy can be obtained more safely and are definitely more reliable than nasotracheal suction (see Chapter 10) in obtaining uncontaminated lower respiratory tract secretions for culture, nasotracheal suction is not recommended for this purpose. Because the catheter does not reach the vocal cords or enter the trachea, nasopharyngeal suctioning is associated with fewer complications than nasotracheal suctioning [3]. This requires insertion to a depth that corresponds to the distance between the middle of the patient’s chin and the angle of the jaw, just below the earlobe. Before removal of the endotracheal tube, perform nasopharyngeal and oropharyngeal suctioning to clear secretions that have pooled above the vocal cords for the inflated cuff. In preparation for deflating the cuff, place the endotracheal suction catheter tip just distal to the endotracheal tube to aspirate any secretions that gravitate downward when the cuff is deflated. Augmentation of Cough Effectiveness Although mucociliary transport is the major method of clearing the airway in healthy subjects, cough is an important reserve mechanism, especially in lung disease [3]. The ineffectiveness of voluntary coughing in normal subjects to clear tagged aerosol particles in the lower airways is probably due to the inability of the moving airstream to interact appropriately with the normally thin mucus layer on which the particles were deposited [3]. Once there is sufficiently thick material in the airways, the effectiveness of cough depends on achieving a high expiratory flow rate of air and a small cross-sectional area of the airway during the expiratory phase of cough to achieve a high linear velocity (velocity equals flow/cross- sectional area); therefore, any condition associated with decreased expiratory flow rates or reduced ability to compress airways dynamically places affected patients at risk of having an ineffective cough. All conditions that may lead to an ineffective cough interfere with the inspiratory or expiratory phases of cough; most conditions affect both. Cough effectiveness is likely to be most impaired in patients with respiratory muscle weakness because their ability to take in a deep breath in (flow rates are highest at high lung volumes) and to compress their airways dynamically during expiration are impaired, placing them at double liability. The muscles of expiration appear to be the most important determinant for producing elevated intrathoracic pressures, and they are capable of doing so even with an endotracheal tube in place [3]. Therefore, tracheostomy should not be performed in the intubated patient just to increase cough effectiveness. Assessment of Cough Effectiveness Ideally, clinicians would like to predict clinically or physiologically when a patient is at risk of developing atelectasis, pneumonia, or gas-exchange abnormalities because of an ineffective cough. The existing data that relate to assessment of cough effectiveness were generated in patients with muscular dystrophy and myasthenia gravis [3,78]. The goal of protussive therapy is to increase cough effectiveness with or without increasing cough frequency. The conflicting results with these two types of bronchodilators suggest that terbutaline achieved its favorable effect by increasing hydration of mucus or enhancing ciliary beating, and these overcame any negative effects that bronchodilation had on cough clearance. If bronchodilators result in too much smooth muscle relaxation of large airways, flow rates can actually decrease even in healthy individuals when more compliant large airways narrow too much because they cannot withstand dynamic compression during forced expirations [3]. Expiratory Muscle Training Because expiratory muscle weakness diminishes cough, strengthening the muscles may improve cough effectiveness. In quadriplegic subjects, there was a 46% increase in expiratory reserve volume after a 6-week period of isometric training to increase the clavicular portion of the pectoralis major [82]. This technique may improve cough by allowing patients with neuromuscular weakness to generate higher intrathoracic pressures [3].

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