Pathophysiology of COPD

Chronic obstructive pulmonary disease (COPD) is a condition that refers to a group of lung diseases that cause inflammation leading to blockage of airflow through airway during exhalation, hence making smooth breathing progressively  difficult (Nagaratnam et al., 2018). Some of the main diseases that constitute the COPD include, emphysema, and chronic asthmatic bronchitis. According to Vogelmeier et al. (2017), damage to the airways inhibits the gaseous exchange in the lungs. Smoking, infection caused by virus and bacteria, and air pollution results to exacerbations of COPD indicative of worsening of the underlying chronic inflammation of the airways, and the frequency of the exacerbations is one of the important determinants of health-related quality of life (Divo et al., 2015). According to Kaufman and Kent (2008), some of the definitive symptoms of COPD include coughing and sputum production which can continue for a period beyond three months, shortness of breath associated with laboured breathing especially after heavy exercise, tightness of the chest, and wheezing.   The management and treatment strategies of COPD involves a combination of Pharmacological therapy, pulmonary rehabilitation, and behavioural therapy (Vogelmeier et al., 2017).

According to Croft et al. (2018), in the developed countries, COPD is one of the principal causes of morbidity and mortality. For example in Australia COPD is the second leading cause of individual disease burden after coronary heart disease (Australian Institute of Health and Welfare [AIHW], 2018). According to AIHW (2018), 10% of the annual deaths in Australia are directly caused by respiratory related diseases just second after cancer related disease. Furthermore, COPD is among the most common disease of the elderly in Australia.

Therefore, this essay is a case study analysis of a patient admitted with Infective exacerbation of COPD, Influenza A, and Pneumonia. This essay focuses on the information related to patient case summery, succinct of the aetiology of COPD based on the primary causes leading to current hospital admission, review of medical history, relevant diagnostic investigation, and strategies for treatment and management of the COPD patient.

Based on the medical history Mrs Y has been in the past diagnosed with a myriad of conditions including atrial fibrillation, Chronic Obstructive Pulmonary Disease (COPD), hypertension, osteoporosis, chronic kidney disease, dementia, and bilateral cataracts with intraocular lens replacement. At the same time, from the medical history Mrs Y was revealed to be having penicillin hypersensitivity. Mrs Y aged 89 years old female who on review of a family history revealed that she depends on her son for help, she is a current heavy smoker, and not currently registered as one of the beneficiary of government’s social services. Based on the received referral documents from a local medical officer the patient presented with clinical signs including febrile illness, cough, and tachypnoea.

A close physical examination of the patient vital signs revealed that she was experiencing intermittently with stimulation like blood pressure as a result Haloperidol drug was given to her to help calm her down. Further, diagnostics were made based the results of chest X-ray revealing increased consolidation in Left lower lobe, right basal creps, and there were signs of poor inspiration effort and minimal wheeze. Furthermore, microbial tests on flu swab revealed a positive results for Influenza A confirming the earlier fear of Influenza A Viral infection, whereas the Full heamogram (FHG) report, Urea electrolyte creatinine (U/E/C), and blood culture were normal. The diagnostic confirmed the impression made that Mrs Y was suffering from the following conditions: infective exacerbation of COPD, Influenza A viral infection, Pneumonia on background of COPD, and Delirium secondary to her infection on the background of current work up of dementia. Therefore, the doctor’s treatment and management strategy involved pharmacological therapy by prescribing drugs including Oseltamivir, Aspirin 100mg (OD), Panadol Osteo two tablets (T.D.S), Tiotropium puffer 18mcg mane, Seretide 500/50 puffer 2 puffs two times a day (B.D), Moxifloxacin Intravenous administration: 400mg nocte, Atrovent Nebuliser 250 mcg QID, and Salbutamol nebuliser 2.5-5 mg 4th hourly.

Viral infection and COPD

Pathophysiology of COPD

Mrs Y medical history revealed that she was current smoker. According to (Riesco et al., 2017; McCarthy et al., 2015), smoking is a leading risk factor that contribute to the occurrence of COPD. The smoke acts as an allergen that provokes hypersensitivity reaction whereby, T-helper and T-cytotoxic cells proliferates and release inflammatory mediators leading to airways smooth muscles contraction, bronchial wall inflammation, and airways mucus hypersecretion (Wawrzyniak et al., 2017; Siahpush et al., 2015). At the same time, repeated damages and regeneration of bronchial smooth muscles epithelium as a result of frequent exposure to smoke leads to physiological dysfunction and cellular changes of airways epithelial cells (Gon and Hashimoto, 2018). Therefore, the hallmark of COPD is increased obstruction and unresponsiveness of the airway. According to Riesco et al. (2017), continues smoking increases the decline Forced Expiratory Volume in one second (FEV1) and the patient clinical presentations include breathlessness cough, tachypnoea, and lung parenchymal destruction.

Viral infection and COPD

According to Hewitt et al. (2016), exacerbations of COPD can be caused by upper respiratory viral infections such as Influenza A virus and the severity of the infection depends on the specific virus and the host factors. The Patient’s body immune response releases T-cytotoxic cells, natural killer cells, and interferons leading airway inflammation and increased mucus production. Influenza A virus has been cited to greatly impact the elderly patients suffering from the COPD in terms of morbidity and mortality (Ritchie et al., 2015). Therefore, the airway inflammation and obstruction caused by hypersecretion of mucus lead to reduced airflow resulting to cough, difficulty in breathing, and tachypnoea as experienced by Mrs Y at the time of admission.

Mrs Y presented with clinical manifestation including febrile illness, cough, and tachypnoea. From the history given by Mrs Y it is evident that she developed COPD due to exposure to associated risk factor such as smoking and age. The presence of cough as presented by the patient further pointed at patient having COPD. According to Vogelmeier et al., (2017), patient with COPD usually present with persistent cough accompanied with sputum production and physical examination reveals hyperinflated chest and together with vesicular breathing indicative of airway obstruction. Moreover, COPD patient’s experiences difficult breathing which is associated with wheezing the worsening of the suggested symptoms is indicative of episode of acute exacerbation. The chest X-ray results for Mrs Y suggested right basal creps, poor inspiration effort and minimal wheeze. Furthermore, the X-ray revealed consolidation of left lobe. This is a fact supported by Nagaratnam et al. (2018), who suggested that chest X-ray results for persons suffering from COPD shows consolidation and flattened diaphragm as a result of hyperinflation with no evidence of cardiomegaly. It is important to perform differential diagnosis to rule out congestive heart failure due to the fact that congestive heart failure also present with wheezing. Mrs Y didn’t present with any symptoms that would suggest cardiovascular related diseases. However, an echocardiogram would be done to check for atrial hypertrophy.

Patients suffering from bronchiectasis also presents with clinical manifestations that are similar to COPD including persistent cough with production of sputum and shortness of breath and wheeze as suggested by Divo et al. (2015). However, in bronchiectasis patients produces purulent sputum. Mrs Y on admission presented with cough and no history of purulent sputum was given. Chest plain radiography would be appropriate to further offer differential diagnosis in order to check for cystic shadow which is typical of bronchiectasis.

COPD Treatment and management strategies

The main objective of pharmacological treatment of a patient suffering from exacerbation of COPD, in this case Mrs Y is to improve airway obstruction due to inflammation caused by Influenza A infection, smoking, and any hypersensitivity reaction caused by environmental allergens. According to Montuschi et al. (2014), the immediate treatment of COPD involves opportune administration of a combination of β2 agonist, corticosteroids, antibiotics, oxygen.  In this case study the medical doctor prescribed different drugs to help in the management of Mrs Y condition. The mode of action, drug interaction, side effects of each drug is discussed below;

Salbutamol Nebuliser

Salbutamol is a drug that is classified as a bronchodilator whose main function is to help open up the airways of the patient and allow free flow of oxygen into the lungs of a patient (Andrzejowski and Carroll, 2016). Salbutamol mode of action involves binding to Beta 2 receptors resulting to activation of G-S protein that is conjugated together with the Beta 2 receptor therefore GDP is exchanged to GTP. Consequently, adenylate cyclase enzyme is activated leading to conversion of ATP into cAMP which acts as a secondary massager. cAMP dependent protein kinase A enzyme increases it’s activity due to increased intracellular cAMP leading to alteration of phosphorylation of myosin and lowers intracellular calcium levels within the muscle (Thomas et al., 2017). The reduced muscle calcium levels results into relaxation of the bronchial smooth muscles, hence, bronchodilation (Andrzejowski and Carroll, 2016). Moreover, nebulized Salbutamol solution helps to make breathing easier for patients (Bjermer et al., 2016). In this case study Mrs Y presented with tachypnoea, therefore, salbutamol was drug of choice because it would help the patient by improving the breathing difficulties as presented by the patient. According to Miravitlles et al. (2012), in the management and treatment of COPD, 5mg salbutamol should be administered to the patient through oxygen-driven nebulizer within the first 5 minutes. Salbutamol helps improve the symptoms of patient suffering from COPD including wheezing and shortness of breath accompanied with coughing as suggested by Thomas et al. (2017). However, there are side effects that can be experienced by the patient when using his drug including tachycardia, slow heart rate after two hours of administration, hypokalaemia, and worsening ventilation.

Tiotropium Puffer

Tiotropium Puffer is categorised as a long acting anticholinergic drug (Page Thomas et al., 2017). The mode of action of Tiotropium is based on its ability to prevent vagally mediated reflexes by antagonizing the actions of the nerve transmitter agent called acetylcholine that originates from vagus nerve stimulation. Therefore, it prevents the intracellular high concentration of cyclic guanosine monophosphate (cGMP) that is a result of acetylcholine with the muscarinic receptor on bronchial smooth muscle leading to bronchodilation (Beltaief et al., 2018; Page and Barnes, 2017). Therefore, Tiotropium Puffer prevents bronchospasm and enhance bronchodilation that enables the smooth muscles of the airway to relax leading to improved air flow into the lungs. In this case study Mrs Y presented with difficulty in breathing by administering Tiotropium Puffer 18mcg mane she will have improved breathing hence improving her condition.

Seretide

Seretide is made inform of dry powder and packaged in a device called an Accuhaler, it is made up of two drugs namely salmeterol xinafoate and Fluticasone propionate (Yang et al., 2017). The latter is categorised as corticosteroids. Fluticasone acts by averting the late phase of inflammatory response by reducing the swelling, redness, and drying up of mucus of the smooth muscles of the bronchial walls (Miravitlles et al., 2012). While Salmeterol xinafoate classified as a bronchodilator when taken in combination with fluticasone it helps ease the patients breathing difficulties as witnessed in the case of Mrs Y. According to Vogelmeier et al. (2017), Salmeterol in Seretide is classified as long-acting beta2-agonist and bronchodilator resulting relaxation the bronchial smooth resulting to widening of the airways. In this case study the patient had difficulty in breathing caused by bronchospasm, hence, it was necessary for to administered Seretide drug to Mrs Y to enhance relieving of symptoms of COPD including wheezing and shortness of breath. However, there is drug interaction between and some other drugs including beta-blockers and Ketoconazole (WHO, 2017). Some of the side effects for using include sore throat, headache, tachycardia, and muscle cramps among others.

Atrovent Nebuliser 

Atrovent is classified as anticholinergic drug with its active ingredient called ipratropium bromide (Thomas et al., 2017). It is a good example of bronchodilator that is prescribed to COPD patient for the treatment of bronchospasm. Its mode of action is based on preventing vagally mediated reflexes by antagonizing the actions of the nerve transmitter agent called acetylcholine that originates from vagus nerve stimulation (Beltaief et al., 2018). Therefore, Atrovent prevents bronchospasm and enhance bronchodilation that enables the smooth muscles of the airway to relax leading to improved air flow into the lungs. According to Vogelmeier et al. (2017), Ipratropium which is a short-acting muscarinic antagonist improves the respiratory rates by improving the lung functions. Atrovent is a derivative of and structurally similar to atropine. Therefore, the use is contraindicated in patients with allergy to atropine (Thomas et al., 2017). Some of the side effects of Atrovent include severe bronchospasm, visual impairment, and angioedema among others. 

Moxifloxacin Intravenous administration

Moxifloxacin is a classical respiratory quinolones, an antimicrobials agents which is highly effective against most respiratory pathogens as suggested by Miravitlles and Anzueto (2008). Some of the susceptible microorganisms to this drug include multi drug resistant Streptococcus pneumoniae and Haemophilus influenzae (Miravitlles, 2007). The mechanism of action involves its ability to interfere with topoisomerase which are important enzymes that has critical role in bacterial DNA replication and chromosal division (Miravitlles, 2007). Moxifloxacin is highly absorbed and easily distributed into extravascular spaces with a bioavailability of about 91% and it excellently penetrates into the lung cells especially alveolar macrophages and it binds to serum albumin (Miravitlles et al., 2012). Mrs Y symptom of exacerbations improved after the administering of Moxifloxacin Intravenous administration: 400 mg nocte. Hence, this would improve the condition of the patient. Some of the side effects associated with this drug include nausea, diarrhoea, and dizziness.

Intramuscular injection (IM) Haloperidol

Haloperidol is classified as potent neuroleptic drug which is deaconate ester of the butyrophenone, and its mode of action involves blocking the effects of dopamine and increases its turnover rate (de Berardis et al., 2017). According to Torbic and Duggal (2018), it is 50 times more potent as compared to chlorpromazine on weight basis. Haloperidol activity against the delusions and acts of aggressions are attributed to effective dopaminergic receptor blockage in the brain mesocortex area. Further it inhibits dopamine activities in the nigrostriatal pathways, at the same time, haloperidol exhibits sedative characteristics with strong action against psychomotor agitation (Torbic and Duggal, 2018). Hence, it is effective in treating the states of agitation as expressed by Mrs Y during the admission.

Oseltamivir

According to (“Influenza Antiviral Medications: Summary for Clinicians | Seasonal Influenza (Flu) | CDC”, 2018), Oral oseltamivir is approved by the FDA for treatment of acute uncomplicated influenza virus within 2 days of illness onset. The drug is classified as an antiviral agent, its mechanism of action involves inhibition of neuraminidase action in influenza A virus (Venkatesan et al., 2017). The enzyme neuraminidase is important to in viral replication in that it promotes the release of progeny viruses from infected cells. Oseltamivir is an analogue of sialic acid therefore, it acts by blocking the active site of neuraminidase leaving behind uncleaved sialic acid residue both surface of host cell and envelope of influenza A virus. When the drug is orally administered about 80% of the drug is absorbed in the system and adverse effects of this drug include nausea and vomiting (Venkatesan et al., 2017)

Panadol Osteo

Panadol Osteo is a unique bi-layer tablet incorporating an immediate release and a sustained release dose of paracetamol, and the constant release layer is formulated in such a way that it speedily hydrates to form a gel layer at the matrix periphery thereafter the drug is then released from the matrix by a combination of diffusion and erosion of the gel layer (Ortiz, Calcino, and Dunagan, 2016). The mode of action is such that it inhibits the synthesis of prostaglandin, however, paracetamol have no anti-inflammatory activity (Navarro et al., 2018).  Therefore, it only provides relief from mild to moderate pain and fever. In the case of Mrs Y, it was necessary for the doctor to prescribe Panadol Osteo tablets to ease the pain that was attributed to osteoarthritis, muscle pain.

Ramipril

According to Karagiannis et al. (2007), Ramipril is categorised as a long acting non-sulphydryl converting enzyme inhibitor and it has ester group that must be cleavaged for it to form active diacid metabolite, and  the duration of action taken by the drug is dependent on the renal excretion rate. Daily dosage of 5mg can help control the blood pressure for over a period of 24 hours, however, in patient with cardiac problem low dosage is recommended. Therefore this drug was important for the case due to the fact the patient presented with high blood pressure.

Discussion

Mrs Y presented with symptoms of rapid and shallow breathing attributed to reduced gaseous exchange rate due to inflammation of the airway and hypersecretion of mucus caused the imbalance between carbon dioxide and oxygen in the body. Reduction in maximum expiratory volume per second and reduced respiratory rates flow results to acute respiratory acidosis due hypoventilation causing disturbance in the acid-base equilibrium (Divo et al., 2015). Therefore, Mrs Y might have experienced carbon dioxide retention in the circulatory system leading to tachypnoea, this would be fact checked by increased in paCO2 and PH in the borderline if blood gas tests were performed. The doctor rightfully prescribed Bronchodilators and anticholinergic which would increase FEV1 and reduce dynamic hyperinflation. According to Vogelmeier et al. (2018), when both β₂-agonist and anticholinergic agents are used to relieve patient’s symptoms leading to relaxation of airway smooth muscles, improved lung function, health status.

Mrs Y also presented with symptoms of typical upper respiratory tract infection. Patient with exacerbation COPD at times have compromised immune system related to long use of steroids such as prednisolone as well as acute infection, hence, they are at a risk of developing secondary infection including viral and bacterial infection according to Yang (2017). Therefore, the inclusion of both Oseltamivir and Moxifloxacin as in the case of Mrs Y.

Under nursing management Mrs Y needed counselling quitting smoking as a form of lifestyle behavioural change.  According to McCarthy et al. (2015), by quitting smoking an individual’s risks of progression of COPD and mortality are reduced.

Conclusion

In the developed countries, COPD is one of the principal causes of morbidity and mortality.. Pharmacological treatment and nursing management are critical when taking care of patient suffering from COPD. Smoking and old age are some of the risk factors for the development of COPD. Furthermore, early and accurate diagnosis of COPD and the patient’s change of behaviour is critical in treatment and management of COPD.

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