Introduction drug induced pneumonitis.
Drug induced pneumonitis is a type of non-infectious lung tissue inflammatory diseasecategorized by infiltration of interstitial and alveolar (Cui et al., 2017). Interstitialpneumonitis involves the pleura, multiple structures of the respiratory system, airways, lungparenchyma, mediastinum, pulmonary vasculature and the neuromuscular system (Yonemoriet al.
, 2016). This often exhibits as a dyspnea, dry cough, chest tightness, low grade fever,pain, tachypnea, tachycardia, cyanosis, and fatigue. The most common form of drug inducedlung injury is drug-induced interstitial pneumonitis. Pneumonitis can cause permanentrespiratory failure which requires chronic oxygen therapy (Yonemori et al., 2016).Pneumonitis is a side effect associated with several cancer treatments, including radiationtherapy and chemotherapy as well as newer targeted drugs and immunotherapies (Yonemoriet al., 2016).
Pembrolizumab is a monoclonal antibody that binds to the programmed cell death protein 1(PD-1) receptor and targets programmed death-ligands 1 (PD-L1) found on T-cells and 2(PD-L2), releasing PD-1 pathway-mediated inhibition of anti-tumor proliferation.(Pai?Scherfet al., 2017). A severe adverse effect of Pembrolizumab is pneumonitis, which may causesignificant morbidity and mortality (Kwok, Yau, Chiu, Tse & Kwong.
, 2016). The mediantime from the initiation of therapy to pneumonitis was 2 to 6 months, even though it couldoccur after one to two doses of a PD-1/PD-L1 inhibitor (Li et al., 2017).Mdm. Ken is currently admitted for shortness of breath for few weeks and she was noted tobe long standing dyspnea for few weeks after she was started on Pembrolizumab, Lowpercutaneous arterial oxygen saturation, cough, fatigue, loss of appetite, loss of weight andincreasing requirement of oxygen therapy. The issue identified in this admission includes,lower back pain. The purpose of this essay the author has no previous experience ofmanaging drug induced pneumonitis.
Therefore the author will focus and discuss onpneumonitis and diagnosis and management. Ken was also noted to need minimal assistancein her ADL.Pneumonitis diagnosis and managementPembrolizumab demonstrates significant improvement in progression free survival andoverall survival for patients to compare with chemotherapy (Pai?Scherf et al., 2017).However due to the Pembrolizumab, patients are often exposed to higher risk of pneumonitiscompared with routine chemotherapy (Wu, Hong, Zhang, Lu & Miao., 2017).To rule out pneumonitis, it is important to evaluate promptly for any worsening respiratorysymptoms and treat if symptoms present (Lewis.
, 2016). Pneumonitis usually graded basedon the severity of the clinical symptoms and radiographic changes. Grade one pneumonitis ischaracterized by radiographic changes and clinically asymptomatic. Grade two characterizedby mild to moderate respiratory symptoms, whereas grade three and four pneumonitis willcause severe respiratory symptoms and limit patient’s self-care activities of daily living.Examples: hypoxia, cough dyspnea, fever, chest tightness (Cui et al., 2017). The diagnosis ofpneumonitis should include a physical examination, chest X-ray, High-resolution computedtomography (CT) scan, Arterial blood gas (ABG) analyses and full blood count, bloodaerobic and anaerobic cultures, echocardiogram(ECG), sputum Gram stain and culture(Meyer.
, 2014).Physical examination and history taking is very important which includes details of all recentdrugs taken by the patient any reaction or side effects to drugs, Type of reaction such asitching, urticaria, skin rash, respiratory difficulty, cigarette smoking and alcohol drinking,monitoring vital signs and measuring percutaneous arterial oxygen saturation, palpate forsuperficial lymph nodes for enlarged lymph nodes, auscultate the chest to examine for thebreathing differences between left and right side of lung for the presence of crepitate ralesand for airway lesions (Kubo et al., 2013).Chest X ray is the first radiological investigation in pneumonitis patients, which will help inestablishing disease progression and chronicity (Mikolasch, Garthwaite & Porter., 2017).
Mdm. Ken’s chest X-ray shows, patchy consolidation in the right lower zone, venouscongestion and diffuse septal lines are present and ECG showed sinus tachycardia andtroponins were negative.CT scans may show diffuse areas of ground-glass opacity with intra lobular interstitialthickening as the major findings in anti-neoplastic agent induced pneumonitis (Matsuno.,2012).CT scan helps to evaluate the extent to upper middle and lower lung (Nishino et al.,2016). Mdm.
Ken’s CT scan shows, Left supra clavicular lymph nodes are palpated whichcorresponds to the findings of the computed tomography (CT) scan of the thorax, abdomenand pelvis, And also showed innumerable nodules and ground glass opacities in bilaterallungs, The smooth septal thickening in the left lung, patchy opacity is seen in the right lowerlobe and bilateral pleural effusion. Which are indicative pattern of pneumonitis Apart fromthe pneumonitis, there were no other significant abnormal findings.Arterial blood gas (ABG) analysis may be useful in individual patients before initiatingtherapy with a drug known to cause pulmonary toxicity, especially in cancer patients. ABGused to asses gas exchange and lung function (Mohammed & Abdelatief., 2016).
A blood gasobtained from the patient on 4 L/minute of nasal O2 demonstrated a pH of 7.46, pCO2 42.2mm Hg, and pO2 106.6 mm Hg. Blood culture test used to identify infection and type ofmicro-organism causing infection. Prophylactic Broad-spectrum antibiotics were started forMdm.
Ken while waiting for blood culture, sputum gram stain and culture results. Allcultures and gram stain for infections were negative.Pneumonitis treatment includes discontinuing immunotherapy treatment especially in gradethree and four pneumonitis, corticosteroid therapy, oxygen therapy, pulmonary rehabilitation(Eigentler et al., 2016). Mdm. Ken’s treatment was discontinued. The initial treatment isadministering high doses of intra venous corticosteroids one to two milligram per kg per dayand required to taper the dose over few weeks if symptoms improved (Lewis.
, 2016).Corticosteroids are Immunosuppressive anti-inflammatory agents and it helps to reduceinflammation of the lung by suppressing the immune system (Meyer., 2014). However,suppressed immune system increase the risk of developing infections, frail bones, insomniatherefore corticosteroids can be dangerous (Meyer., 2014). Hyperglycemia is the mostcommon side effect of corticosteroids which will increases the glucose levels up to 68%compared to baseline. Therefore it is essential to monitor blood glucose level from the start ofcorticosteroids (Tamez-Pérez.
, 2015). Mdm Ken was started on IV dexamethasone 8 MgTDS for four days and tapered to 8Mg BD and blood glucose was monitored twice a day.The aim of pulmonary rehabilitation is to decrease symptoms, optimize functional state,increase participation there by improve quality of life. Pulmonary rehabilitation programincludes patient education on exercise to strengthen essential muscle groups, lower and upperextremity exercise, breathing technique using incentive spirometry, diaphragmatic breathing,and pursed lip breathing, respiratory therapy evaluation(Sharma & Singh.
, 2011). Progressiveweight loss occurs from inadequate dietary intake, increased resting energy expenditure.Malnourishment will leads to imbalance in energy and weight loss. Therefore early screeningand proper management is important.
Nutritional status should help to improve the state ofhealth, respiratory muscle function (Sharma & Singh., 2011). Mdm. Ken was referred tophysiotherapy and nutritional therapy.