NU 641 Discussion: Infection Case Study

Sample Answer for NU 641 Discussion: Infection Case Study Included After Question

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Answer the following questions in three well-developed paragraphs (450–500 words) using APA formatting, integrating two evidence-based resources to include clinical practice guidelines as well as the course textbook.

Anthony Miller, a 59-year-old male, presents to the clinic with complaints of cough, shortness of breath, and increased sputum production. His past medical history is significant for COPD with chronic bronchitis, hypertension, diabetes, and hyperlipidemia. He reports that his sputum has increased in consistency and amount over the past few days. His last exacerbation was about 6 months ago, for which he received amoxicillin. This is his third exacerbation in the past year.

He has a 40-pack year history of cigarette smoking and quit smoking 3 years ago. He does not take chronic steroids. Physical exam reveals rhonchi and expiratory wheezes. His vital signs are blood pressure 140/83 mm Hg, pulse rate 80 beats/min, respiration rate 20 breaths/min, and temperature 98.8°F. He has no known drug allergies. A sputum Gram stain in the office reveals purulent sputum (presence of WBCs). Chest x-ray findings are negative for pneumonia.

Diagnosis: Acute Exacerbation of Chronic Bronchitis—Please provide your rationales for each answer with supporting data

  1. Which of the following would suggest the need for antibiotic therapy in A.M.?
    1. Cough, history of smoking, and expiratory wheezes on physical examination
    2. Elevated respiratory rate and shortness of breath
    3. Increased dyspnea, increased sputum production, and increased sputum purulence
    4. History of previous COPD exacerbations, cough, and fever
  2. What is a likely pathogen associated with an acute exacerbation of chronic bronchitis in A.M.?
    1. Mycobacterium tuberculosis
    2. Pseudomonas aeruginosa
    3. Staphylococcus aureus
    4. Streptococcus pneumonia
  3. What antibiotic would be most appropriate to treat an acute exacerbation of chronic bronchitis in A.M.?
    1. Amoxicillin–clavulanate
    2. Azithromycin
    3. Linezolid
    4. Sulfamethoxazole/trimethoprim
  4. What is the mechanism of action of the medication of choice in question #3? Provide rationale.
  5. What kind of counseling points would you provide for A.M.?

A Sample Answer For the Assignment: NU 641 Discussion: Infection Case Study

Title: NU 641 Discussion: Infection Case Study

Most exacerbating of chronic obstructive pulmonary disease (COPD) are usually caused by respiratory tract infections. As such, empiric antibiotic therapy can only be considered when the patient displays signs of bacterial infection. According to the GOLD guidelines, antibiotic therapy is only recommended among patients who are critically ill, and displays at least two of the following symptoms including increased dyspnea, increased sputum purulence, and increased sputum production just as displayed in the case of A.M (Li et al., 2019).  However, not all patients with the three cardinal symptoms will benefit from antibiotic therapy. As such, it is also necessary to consider the evaluation of biomarkers such as procalcitonin to determine patients who are most likely to benefit from antibiotic therapy.

The most common bacteria that are known to cause acute exacerbation of chronic bronchitis include Streptococcus pneumoniae, Moraxella catarrhalis, andHemophilus influenzae (Ritchie & Wedzicha, 2020). However, for the case of A.M, the most likely causative pathogen is Pseudomonas aeruginosa. The patient’s chest X-ray findings revealed negative results for pneumonia. Consequently, Pseudomonas aeruginosa is considered to be one of the most common nosocomial pathogens which become more prevalent among patients with severe underlying disease. A.M displayed a history of significant COPD with chronic bronchitis, hyperlipidemia, diabetes, and hypertension. Additionally, the sputum gram stain revealed purulent sputum present in the white blood cells, which indicates the presence of a bacterial infection.

Antibiotics recommended by the GOLD guidelines for the management of an acute exacerbation of chronic bronchitis include azithromycin, amoxicillin/clavulanate, or doxycycline. However, in the case of patients who have used antibiotics in the last 30 days, or present with the recurrent disease just like for the case of A.M use of an antibiotic from a different class such as Sulfamethoxazole/trimethoprim (SMX/TMS) is recommended. SMX/TMS is a combination of two active pharmaceutical ingredients with a synergistic effect (Joyner et al., 2020).

Sulfamethoxazole is a sulfonamide that acts by inhibiting the synthesis of bacterial dihydrofolic acid as a result of being structurally similar to an endogenous substrate known as para-aminobenzoic acid (PABA). Sulfamethoxazole is a competitive inhibitor of dihydropteroate synthase which is responsible for converting PABA to dihydrofolic acid essential for the synthesis of purines and DNA of the bacteria, hence leading to a bacteriostatic effect (Dietrich et al., 2019). Trimethoprim on the other hand acts by reversibly inhibiting dihydrofolate reductase, which is an essential enzyme responsible for the formation of tetrahydrofolic acid (THF) from dihydrofolic acid (DHF).

THF is essential for the synthesis of bacterial nucleic acids and proteins. A combination of the two drugs inhibits two consecutive steps in the synthesis of bacterial nucleic acid and proteins exhibiting a bactericidal effect. The patient must be informed that this medication can lead to increased sensitivity to the sun, hence A.M should limit his time in the sun when using SMX/TMS. Additionally, the drug is known to affect the blood sugar levels of patients with diabetes, like A.M. As such, he should be advised to monitor his blood sugar levels more frequently.


Dietrich, E., Klinker, K. P., Li, J., Nguyen, C. T., Quillen, D., & Davis, K. A. (2019). Antibiotic stewardship for acute exacerbation of chronic obstructive pulmonary disease. American Journal of Therapeutics26(4), e499-e501. DOI: 10.1097/MJT.0000000000000717

Joyner, K. R., Walkerly, A., Seidel, K., Walsh, N., Damshekan, N., Perry, T., & Soric, M. M. (2020). Comparison of narrow-versus broad-spectrum antibiotics in elderly patients with acute exacerbations of chronic obstructive pulmonary disease. Journal of Pharmacy Practice, 0897190020938190.

Li, Z., Yuan, X., Yu, L., Wang, B., Gao, F., & Ma, J. (2019). Procalcitonin-guided antibiotic therapy in acute exacerbation of chronic obstructive pulmonary disease: an updated meta-analysis. Medicine98(32). DOI: 10.1097/MD.0000000000016775

Ritchie, A. I., & Wedzicha, J. A. (2020). Definition, causes, pathogenesis, and consequences of chronic obstructive pulmonary disease exacerbations. Clinics in chest medicine41(3), 421-438.