Asthma and Medicine Management - Essay Example

?Pathophysiology of asthma and pharmacology of drugs for the treatment of asthma Introduction Asthma is a disorder that will turn out to be a life-threatening condition if it is not treated and controlled appropriately. The following are the important points in relation to the pathophysiology of different asthmatic conditions and pharmacokinetics and pharmacodynamics of the drugs meant for the treatment of asthma with reference to the case scenario presented. 1) What is asthma? Asthma is a chronic inflammatory airway disorder marked by airflow obstruction and airway hyperresponsiveness to a multiplicity of stimuli. This widespread but variable airflow obstruction is caused by bronchospasm, edema of the airway mucosa and increased mucus production with plugging and airway remodeling. It is a type of chronic obstructive pulmonary disorder (COPD) which is a long-term pulmonary disease characterized by increased airflow resistance. Other types of COPD include chronic bronchitis and emphysema. 2) Incidence of asthma and implications of this. There are an estimated 234.9 million people affected by Asthma worldwide of which 28.8 million are in Europe and about 5.4 million are in the U.K. Incidence of new cases occurs mostly in children. In England about 64,000 hospital admissions took place for asthma in 2008/09. Globally 287000 deaths occurred in 2004 and there were 1034 deaths in England and Wales due to asthma in 2008 (Ward, Toledano, Shaddick, Davies, & Elliot, 2012). (NICE, 2013). 3) What are the common signs and symptoms of asthma? Common symptoms are wheezing, breathlessness, tightness in the chest, and cough. These symptoms can be worse at night and in early morning. They can arise after exercise, allergen exposure and cold air (Meerabeau & Wright, 2011). 4) Pathophysiology of asthma and relation to the case scenario. “The pathophysiology of asthma is complex in that it is characterized by airway inflammation, intermittent airflow obstruction and bronchial hyperresponsiveness” (Morris & Mosenifar, 2013) . Airway inflammation “The Airway inflammation in asthma can be acute, subacute or chronic” (Morris & Mosenifar, 2013). Airflow obstruction is also caused by swelling of airway and secretion of mucus which also cause bronchial reactivity. “Mononuclear cell and eosinophill infiltration, mucus hyper-secretion, desquamation of epithelium, smooth muscle hyperplasia and airway remodeling” (Morris & Mosenifar, 2013) are also characteristics of airway inflammation. Airflow obstruction Airflow obstruction results due to changes taking place in the form of acute bronchoconstriction, airway edema, and chronic mucus plug formation, and airway remodeling. Acutebronchoconstriction occurs due to exposure to aeroallergens when immunoglobulin E-dependent mediator is released. The aeroallergen exposure which is the primary reason for the early asthmatic response causes edema in the away that occurs after 6-24 hours which is known as the late asthmatic response. Chronic mucus plug formation will take several weeks to subside as it contains exudates of serum proteins and cell debris. Airway remodeling is so called because of structural changes occurring due chronic inflammation and can affect the reversibility of airway obstruction. Airway obstruction results in reduced airflow in and out of the respiratory system. This leads to lowered ability to expel air resulting in hyperinflation. The airway remodeling causes overdistension which helps maintain airway function and improve expiratory flow but overtime it alters pulmonary mechanics and increases breathing modulation. Bronchial hyperresponsiveness Hyperinflation which is in response to airflow obstruction is however is short-lived due to tidal volume approaching the volume of the pulmonary deadspace and the resultant is known as alveolar hypoventilation. It leads to ventilation-perfusion mismatch. The mismatch is also due to vasoconstriction as a result of alveolar hypoxia. Vasoconstriction is also an adaptive response to the above said mismatch (Morris & Mosenifar, 2013). Robert became asthmatic since the age of 7 and had been well managed without any asthma attack for several years now. Now at the age of 32, he has had the attack again forcing him to use Salamol inhaler with 2 puffs (100 mg/puff) three times a day. It shows that his condition is due to airway inflammation, airflow obstruction and bronchial hyperresponsiveness. As a word of caution, it must be noted that “all that wheezes is not asthma”. There is a long list of asthma masquerders. COPD and VCD are on the top of the list of conditions mistaken for or confused with asthma. If the conditions are diagnosed as COPD, treatment plan must be different from that of asthma. VCD i.e Vocal Cord dysfunction if correctly diagnosed, harmful medications for asthma and cost involved can be avoided (Tilles, 2006). 5) Pathophysiology of acute exacerbation of asthma and relation to case scenario. In acute asthma exacerbation one or more of the following features can be observed. Accessory muscle activity, paradoxical pulse over 25 mmHg, heart rate > 100 beats/min, respiratory rate > 25-30 beats/min, speaking difficulty, peak expiratory flow rate (PEF) or forced expiratory volume in 1 second (FEV1) , 50 % predicted and an arterial oxygen saturation 90-92 % . These conditions can be mitigated in most of the patients with intensive inhalation of bronchodilators and systemic corticosteroids. This life threatening asthmatic condition is known as acute asthma exacerbation which leads to respiratory failure in spite of aggressive medical therapy and needs to be supported by life-sustaining therapies to overcome the acute attack. Mechanical ventilation may have to be resorted to. Only when all conventional treatments fail, intubation is used as a last resort. Robert’s pulse is 101 bpm, blood pressure 143 /80 mmHg, Respiratory rate is 28 breaths per minute. These match with more than one of the above features of acute asthma exacerbations. i.e pulse, respiratory rate shown above as 25 mmHg and 25-30 beats /min respectively. Pathophysiology: Acute asthma exacerbation is characterized by narrowing of airway leading to limited airflow. Bronchial hyperresponsiveness causes reduction in airway caliber but other important causes are airway edema and enhanced mucus production associated with airway inflammation. The inflammation is caused by immune reaction resulting from respiratory viruses, allergens, or inhaled irritants. Acute asthma exacerbation occurs due to increased work of breathing caused by expiration which becomes as an active process with impaired lung emptying while inspiration is normal initially. When there is severe airflow obstruction, expiration is impaired by the next inspiratory before end-expiratory lung volume reaches a static equilibrium or functional residual capacity (FRC). Air trapping or hyperinflation is caused by three factors: Tidal volume, expiratory flow limitation, and expiratory resistance (Vincent, 2010). Differential diagnosis to rule out asthma : In case of foreign body/obstruction, it may result in a localized wheeze at the particular site of obstruction, bronchodilators not reducing the condition , foreign body aspiration are the differentiating signs/symptoms. Differentiating tests are; a radiopaque foreign body appears on a plain radiograph or the CT scan of the chest suggests endoluminal obstruction. Fiberoptic bronchoscopy is the appropriate test for diagnosis and treatment of foreign body in the airway. VCD can be diagnosed through a video laryngostroboscopic exam shows paradoxic vocal cord movement. If it is due to cardiac dysfunction, there must a history of left ventricular dysfunction accompanied by the signs and “symptoms of heart failure including crackles, and rales on auscultation of the lungs and peripheral edema.”. Similarly emphysema/COPD, carcinoid syndrome, pulmonary embolism, allergic bronchopulmonary aspergillosos (ABPA) pneumothorax should all be ruled out in cases of seeming exacerbations of acute asthma (BMJ, 2013). 6) How is an acute exacerbation of asthma defined or diagnosed: BTS guidelines? BTS guidelines have defined acute exacerbation of asthma according to levels of severity. Thus, near fatal asthma is characterized by PaCO2 and /requiring mechanical ventilation with raised inflation pressures. Life threatening asthma is defined by the presence of any one of the following features presented by a patient with severe asthma. Altered conscious level measured as PEF < 33% best or predicted. Exhaustion measured by SpO2 50-75 % best or predicted and no features severe asthma. Brittle asthma is defined as Type 1: wide PEF variability (. 40 % diurnal variation for ¦> 50 % of the time over period > 150 days) despite intense therapy. Type 2: sudden severe attacks on a background of apparently well controlled asthma.) (BTS, 2008, 2012 (revised) , p. 59). 7) Treatment guidelines for acute exacerbation of asthma: BTS guidelines: Relation to the scenario Supplementary oxygen is given to hypoxemic patients with a facemask. For maintenance of SpO2 of 94-98%, Venturi mask or nasal cannuale with flow rates should be used to adjust flow rates (BTS, 2008, 2012 (revised) ). Best treatment of acute exacerbations of asthma is their prevention. Inhaled Corticosteroids (ICS) therapy is the treatment of choice to control asthma symptoms and prevent asthma exacerbations of asthma. In the most severe cases ICS therapy along with a long-acting ?-adrenergic agonist (LABA) controls asthma better than with ICS alone. ICS therapy however in general improves control of the disease with reduced frequencies of repeat medication of such short-acting ?-adrenergic agonist and lung function measurements like peak expiratory flow rates or forced expiratory volume in 1 second (FEV1). ICS also consistently reduces airway “hyperresponsiveness in asthma along with reduction in airway responsiveness triggers like histamine, cholinergic agonists, allergens, exercise, fog, cold air, bradykinin, adenosine, and irritants such as sulfur dioxide and metabisulfites” (p117) . CS administration through oral or systemic route is retained for acute severe exacerbations of asthma as they shorten the recovery time from an exacerbation. This is continued for 1 to 2 weeks until there are signs of recovery. Short-shots of CS therapy such as prednisolone for two weeks to a patient with stable asthma at 40 mg per day are given to predict the degree of reversibility of airflow obstruction (Wenzel & Wenzel, 2011). Robert is being given prednisolone 30 mg once a day for 5 days as part of CS therapy to control acute exacerbation which medication is within the limits of 40 mg per day as per the BTS guidelines. Salbutamol 5 mg four times a day and Atrovent 0.5 mg four times a day are also given via oxygen driven nebuliser as per the guidelines. 8) Triggers for asthma: relate this to your scenario and education and information for the patient in terms of management of asthma Conditions or factors that cause asthma are triggers of asthma. It is a well-known fact that Allergens are triggers of asthma. High exposure to allergens in utero or in early childhood leads to allergic sensitization in people who are predisposed. The high exposure manifests as skin-prick tests or increased levels of specific IgE in serum. These factors result in allergic disease. Triggers are environmental factors that can lead to acute asthma attack. The triggers are classified as allergic and nonallergic irritant factors. Common allergic triggers are house dust mite, can dander, dog dander, cockroaches, grass pollens and tree pollens. Common nonallergic triggers are viruses, exercise, cigarette smoke, thunderstorms, air pollutions, and emotional trauma. Robert is asthmatic since his childhood. He has not had attacks for several years now until he has taken up the course of environmental science which exposes him to asthma triggers stated above one can come across while encountering grass and tree pollens as part of one’s occupational study. Part B Salbutamol, Prednisolone, and Ipratropium bromide are the three identified drugs in the treatment of asthma. Salbutamol Salbutamol is administered through the routes of inhalation, tablet, oral liquid, intravenous injection, subcutaneous injection, and intramuscular injection. Mechanism of action: Salbutamol stimulates beta2 adrenoceptors in the airways thereby producing intracellular cyclic adenosine monophosphate (cAMP). This cAMP reduces intracellular calcium and enables bronchodilatation. Side/adverse effects: generally tremor and tachycardia and rarely headache, palpitations, hypokalaemia, muscle cramps, insomnia are experienced. However the rare side effects are dose dependant and hence common with high doses. While there are no contraindications, there are interactions with certain drugs. In respect of corticosteroids in high doses along with high doses of Salbutamol, there is an increased risk of hypokalaemia as also with loop or thiazide diuretics. Similarly increased risk of hypokalaemia occurs if given with theophylline (Chatu, 2011). Salbutamol is prescribed with the specific aim of its action at beta adrenoceptors in the bronchi since the drug is beta, adrenoceptor agonist. It therefore acts as a bronchodilator capable of easing breathing in asthma. Since its action not adrenoceptor-specific, it can act on other beta adrenoceptors in the body especially in cases of high doses resulting in increased receptor occupancy. This is the reason why some side effects occur. Action on other adrenoceptors causes palpitations and increased occupancy at non-bronchial beta adrenoceptor causes tremor (Paul & Deborah, 2012). Pharmacokinetics of Salbutamol: It refers to absorption, distribution, metabolism and excretion of the drug (Noel & Diane, 2013). The drug is well absorbed on oral administration and undergoes rapid and extensive metabolism (Ward & Hisley, 2009) . Pharmacodynamics is about what drug does to the body having a therapeutic effect. Salbutamol that binds with Beta2 adrenoceptor of the smooth muscle in the lungs resulting bronchodilatation (Blair, 2011). Prednisolone This drug, a corticosteroid is given in the case of acute exacerbations of bronchial asthma and for some other conditions. Routes of administration are oral and intra muscular. Oral: 5-60 mgs/day and I.M. 10-40 mg. only 10 mg per day is insisted for long-term therapy. The drug is contra indicated in peptic ulcer, acute psychosis, cushing’s syndrome, herpes simplex, keratitis, CHF and lactation. Pharmacokinetics: It is metabolized into the liver and its bioavailability is 50-80 % after oral administration (WebHealthCentre, n.d.). Rapidly absorbed in to GI membrane, prednisolone’s peak effects occur after 1-2 hours. The corticosteroid enters into the breast milk and cross the placenta. Prednisone gets metabolized by the liver to the active metabolite prednisolone and further metabolized into inactive compounds to be ultimately excreted into urine (Schein, n.d.). . Absorption It is immediately absorbed from the G.I.tract. A delayed release formulation can have a four-hour release time. Half-life 3-4 hours, moderately high protein-binding and excreted in the urine (DrugBank, n.d.), (Qizlet, n.d.). Pharmacodynamics Acute inflammatory process is suppressed. It prevents cell-mediated immune reactions. Peak action in 1-2 hours and duration is 1 to 1.5 days (Qizlet, n.d.). Ipratropium bromide It is presented in solution form for inhalation at 0.02 % i.e 500 mcg/vial. It antagonizes action of acetylcholine on bronchial smooth muscle in lungs and thereby enables bronchodilatation. Pharmacokinetics Absorption: Not readily absorbed and has a mean bioavailability of 7 % (inhalation). Distribution: It is protein bound 0 to 9 %. Partially metabolized and almost half the dose excreted in the urine unchanged in IV administration. The t ? is 2 hours (Drugs.com, 2013) . 4) Why are steroids recommended in all acute exacerbations of asthma: BTS guidelines? Steroids that are inhaled have proved to be effective as a preventer drug. The steroids should be considered in cases of patient having exacerbation of asthma recently in the last two years. (Patient.co.uk, n.d.) The three drugs given to Robert are Salbutamol, Ipratropium bromide and prednisolone. Pharmacology of these drugs ensures that they are absorbed to act on the targeted sites and get excreted in urine. The 6 Rs of medicines management: The 6 Rs of medicine management 1) Right medicine, 2) Right Records, 3) Right Dose, 4) Right Time, 5) Right Route, and 6 ) Right Patient (NHS, 2013). Right medicine refers to the need to compare the medicines ready for administration with the medication order so that right medicines are actually given. Right records refer to proper documentation in that the administrator will record the patient’s response to the medicines administered. Prior to it, the administrator has to record the status of the patient before the administration. Right dose refers to it should be ensured that the right dose is given by triple checking any calculations and have them rechecked by another team member. Right time refers to the timely administration of the prescribed medicine by proper checking of the medication order. The person prescribes should mention the frequency with which the medicines should be given. Right Route refers to the need to check with the medication order thrice and rightly identify the route. Right patient or client refers to the need to identify the right patient with reference to the medication order and the client’s bracelet (Tracy, n.d). Robert has been prescribed with one drug to be administered orally and two drugs through oxygen driven nebuliser. These are in accordance with the 6 R’s stated above. Care and management of nebulisers in practice (equipment and infection control) The chamber of the nebulizer, mouthpiece or mask has to be cleaned in warm soap water, rinsed and dried after each nebulisation. It has been so advised as it reduces the possibility of growth of microorganisms inside the chamber. Such a practice also prevents formation of crystals from the drug and blocking the jets. The tubing should be allowed to get wet and it should be dried after the nebulisation by blowing compressed air. Wet tubs should be replaced since wet tubing will allow growth of bacteria. As part of infection control and prevention of it from being passed on to others, each patient should have their own tubing, nebuliser and mask/face mask. Mouthpieces and facemasks should be discarded once in three or four months in order to minimize the risk of bacterial growth. Compressors should be disconnected from electricity and wiped down with a damp cloth in order to prevent dust and dirt entering and impair its functioning. Compressors should be serviced once in a year to make it efficient and safe to use (Den, 2010). Patient education regarding nebulisers and specific drug therapy for this patient Asthmatic patients should be made aware of possible triggers that will provoke an asthmatic attack. The nurse should ensure that patient uses the required inhaler technique (Den, 2010). Education and advice regarding asthma management (particularly important due to problems highlighted with concordance and asthma): British Guidelines on the management of Asthma recommend 1) Stepping up or down the treatment depending upon the severity for proper control of the disease and keeping the drug related side effects at a minimum. 2) Appropriate treatment suitable for the initial severity of disease should be started. 3) Patient must be consulted and treatment plans and goal negotiated but without losing sight of the aim to minimize the impact of symptoms life , prevent severe exacerbations. 4) Patient should educated on self management providing the patient with written asthma action plans. And 5) Before starting a new drug therapy, check concordance medication/existing plan, appropriate inhaler technique and availability or otherwise of trigger factors (Patient.co.uk, Management of Adult Asthma, n.d.). Robert has been advised with the administration of drugs through appropriate routes as part of stepping up treatment in the wake of his acute exacerbations of his asthmatic condition. He has been advised to treated in this dosage for five days. After five days, there will have to be a review of his condition and decide on stepping down or up in accordance with the severity. British Thoracic Guidelines (BTS) recommends nebulizers being driven by piped oxygen or an oxygen cylinder with high-flow regulator that can deliver a flow rate of > 6 1/min in order to maintain an appropriate oxygen saturation level (O'Driscoll, Howard, & Davison, 2008) . The legal requirement is that medicines should be administered to the right person, at the right time, in the right form of delivery. These are four main areas of accountability in regard to drug administration for a practicing nurse. Medicine Act 1968 governs the regulation of medicines while Misuse of Drugs Act 1971 governs the regulation of controlled drugs. It is a violation of drug license rules to administer a drug other than in the permitted route or form. Thus, if a capsule is crushed open to orally deliver the contents to the patient with swallowing difficulties, the nurse doing so can be suspended for 18 months for investigation by the NMC. . Storage conditions should be observed strictly failing which crystal formation in IV fluids will interfere with delivery of the drug. Nurse as a practicing professional is accountable for actions and omissions and should be in a position to justify his/her decisions (NMC, 2010). Discussion and Conclusion Patient Robert’s pursuing the environmental science education has obviously put him in the present health condition. Being a known asthmatic, continuance of his environmental science education would only aggravate the present condition. Hence, it is desirable that he is advised to discontinue his environmental science education and take up some other suitable course that would not exacerbate his asthma. His continuance would force him to resort to the inhalers and steroids from time to time whenever he gets attacks but in the long run he may stop responding to the present regimen of drugs anymore and his eventual life threatening condition will likely become irreversible. There is no other alternative to the drugs including inhalers he is having at present which should be tapered down once the condition recedes. To be effective these drugs should be taken sparingly and hence it is all the more essential he chooses a different occupation. Stepping down is important as part of review of patients. The factors such as severity of asthma, side effects from treatment, time on current dose, patient’s choice and benefits derived so far should help in deciding which drug to step down first and at what scale. Robert should be maintained at the lowest possible dose of inhaled steroid and tapering down of inhaled steroid dose should be slow. Reduction should be reviewed once in three months by reducing the dose by 25 to 50 % each time. There are suggestions of taking complementary treatments such as acupuncture, buteyko technique, herbal Chinese medicines, homeopathy, hypnosis and relaxation therapies, ionisers and physical exercise therapy. While ionisers are not recommended for treatment of asthma, buteyko breathing technique can be help for patients to control their asthmatic symptoms. For the rest of the complementary therapies, there are insufficient evidence meriting recommendation. References Blair, K. (2011). Medicines Management in Children's Nursing. Exeter, UK: Sage . BMJ. (2013). Acute asthma exacerbation in adults. Retrieved Oct 18, 2013, from epocrates online . BTS. (2008, 2012 (revised) ). British Guideline on the Management of Asthma . Chatu, S. (2011). 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