Respiratory Tract Infections

Influenza Type B

Carries one form of hemagglutinin and one form of neuraminidase, both of which are less likely to mutate than Type-A. Changes through antigenic drift (minor mutations from year to year) when enough drifts occur, an epidemic is likely. Causes epidemics every 5 years

What characteristics a patient must NOT have in order to be diagnosed with CAP?

- Hospitalization 2 days or more in the past 90 days - Residence in a long-term care facility - Receipt of IV antibiotic therapy, chemotherapy, or wound care in the past 30 days. - Attendance at a hospital clinic or receipt of hemodialysis in the past 30 days.

B.P. is a 66-year-old woman who underwent a two-vessel coronary artery bypass graft 8 days ago and has been on a ventilator in the surgical intensive care unit since then. Her temperature is now rising, and a tra- cheal aspirate shows many white blood cells and gram-negative rods. Her medical history includes coronary artery disease with a myocardial infarction 2 years ago, COPD, and hypertension. Which is the best empiric therapy for B.P.? A. Ceftriaxone 1 g/day intravenously plus gentamicin 480 mg intravenously every 24 hours plus linezolid 600 mg intravenously every 12 hours. B. Piperacillin/tazobactam 4.5 g intravenously every 6 hours. C. Levofloxacin 750mg/day IV + Linezolid 600mg IV Q12H D. Cefepime 2 g intravenously every 12 hours plus tobramycin 480 mg intravenously every 24 hours plus vancomycin 15 mg/kg intravenously every 12 hours.

D. Cefepime 2 g intravenously every 12 hours plus tobramycin 480 mg intravenously every 24 hours plus vancomycin 15 mg/kg intravenously every 12 hours. - Ceftriaxone and Gentamycin have limited activity against pseudomonas - Guidelines recommend 2 abx with activity for pseudomonas for patients with severe nosocomial pneumonia and she may also need and antibiotic wit MRSA activity

H.W. is a 38-year-old woman who presents with a fever, malaise, dry cough, nasal congestion, and severe headaches. Her symptoms began suddenly 3 days ago, and she has been in bed since then. She reports no other illness in her family, but several people have recently called in sick at work. Which is best for H.W.? A. Azithromycin 500 mg, followed by 250 mg/ day orally for 4 more days. B. Amoxicillin/Clavulanic acid 875mg orally twice daily C. Oseltamivir 75mg twice daily orally for 5 days D. Symptomatic treatment only.

D. Symptomatic treatment only. - Symptoms are consistent with influenza therefore antibacterial agent would not affect recovery. - Oseltamivir should be initiated within 48 hours of symptoms onset, so because this patient is more than 3 days out from symptoms onset, oseltamivir will not affect recovery.

P.E. is a 56-year-old man who comes to the clinic with a 3-day history of fever, chills, pleuritic chest pain, malaise, and productive cough. In the clinic, his temperature is 102.1 F (38.9 C) (all other vital signs are normal). His chest radiograph shows consolidation in the right lower lobe. His white blood cell count (WBC) is 14,400 cells/mm3, but all other laboratory values are normal. He is given a diagnosis of community-acquired pneumonia (CAP). He has not received any antibiotics in 5 years and has no chronic disease states. Which is the best empiric therapy for P.E.? A. Doxycycline 100 mg orally twice daily. B. Cefuroxime axetil 250 mg orally twice daily. C. Levofloxacin 750mg/day orally D. Trimethoprim/sulfamethoxazole double strength orally twice daily.

A. Doxycycline 100 mg orally twice daily. - Community-Acquired Pneumonia (CAP) - CURB-65 score is 1 at most - No antibiotics in the past 3 months and no comorbidities - Drugs of Choice: Macrolide or Doxycycline - Cefuroxime is not recommended for the treatment of CAP. - Fluoroquinolones are recommended only if the patient has recent antibiotic use or comorbidities - Bactrim is not used for CAP

Community Acquired Pneumonia (CAP)

Acute infection of the pulmonary parenchyma accompanies by an acute infiltrate consistent with pneumonia on chest radiograph or auscultatory findings.

A study is designed to assess the risk of pneumococcal pneumonia in older adults 10 years or more after their pneumococcal vaccination, compared with older adults who have never received the vaccination. Which study design is best? A. Case series B. Case-control study C. Prospective cohort study D. Randomized controlled trial

B. Case-control study - Most ethical, cost-effective and timely method

S.C. is a 46-year-old woman who presents to the clinic with purulent nasal discharge, nasal and facial congestion, headaches, fever, and dental pain. Her symptoms began about 10 days ago, improved after about 4 days, and then worsened again a few days later. Which is the best empiric therapy for S.C.? A. Cefpodoxime 200 mg twice daily. B. Clindamycin 300 mg orally four times daily. C. Amoxicillin/clavulanate 875mg/125mg every 12 hours D. No antibiotic therapy is needed because this is a typical viral infection.

C. Amoxicillin/clavulanate 875mg/125mg every 12 hours - Symptoms suggestive of bacterial sinusitis - Symptoms improved and then worsened. - Augmentin is the first-line agent for bacterial sinusitis - Clindamycin and Cefpodoxime can be used in combination but not monotherapy for penicillin-allergic patients.

R.L. is a 68-year-old man who presents to the emergency department with coughing and shortness of breath. His symptoms, which began 4 days ago, have worsened during the past 24 hours. He is coughing up yel- low-green sputum, and he has chills, with a temperature of 102.4 °F (39 °C). His medical history includes coronary artery disease with a myocardial infarction 5 years ago, congestive heart failure, hypertension, and osteoarthritis. He rarely drinks alcohol and has not smoked since his myocardial infarction. His medications on admission include lisinopril 10 mg/day, hydrochlorothiazide 25 mg/day, and acetaminophen 650 mg four times/day. On physical examination, he is alert and oriented, with the following vital signs: temperature 101.8 °F (38 °C), heart rate 100 beats/minute, respiratory rate 32 breaths/minute, and blood pressure 142/94 mm Hg. His laboratory results are normal except for blood urea nitrogen (BUN) 32 mg/dL (serum creatinine 1.23 mg/ were hospitalized, which would be the best empiric therapy for him? A. Ampicillin/sulbactam 1.5 g intravenously every 6 hours. B. Piperacillin/tazobactam 4.5 g intravenously every 6 hours plus gentamicin 180 mg intravenously every 12 hours. C. Ceftriaxone 1 g intravenously every 24 hours plus azithromycin 500 mg/day intravenously. D. Doxycycline 100 mg intravenously every 12 hours.

C. Ceftriaxone 1 g intravenously every 24 hours plus azithromycin 500 mg/day intravenously. - Ampicillin/Sulbactam has no activity against atypical organisms - Daptomycin is not recommended as monotherapy in hospitalized patients Piperacillin/Tazobactan + Gentamycin combination has no activity against atypical organisms and the increased activity is not necessary for CAP

What is the recommended treament for early onset HAP?

Early onset (more than 2 days and less than 5 days) and no risk factors for multidrug-resistant (MDR) organisms. 1. Third-generation cephalosporin (ceftriaxone) 2. Fluoroquinolone (Levofloxacin, Moxifloxacin, Ciprofloxacin) 3. Ampicillin/sulbactam 4. Ertapenem

Mention some symptoms of CAP.

Fever or hypothermia Rigors, sweats New cough with or without sputum Chest discomfort Onset of dyspnea Fatigue, myalgia, abdominal pain, anorexia and HA

Influenza Type A

Influenza further grouped by variations in hemagglutinin and neuraminidase Changes through antigenic drift or shift (a) Drift: Annual, gradual change caused by mutations, substitutions, and deletions (b) Shift: Less common dramatic change leading to pandemics

What is the recommended treament for late onset HAP?

Late onset (5 days or longer) or risk factors for MDR organisms. 1. Antipseudomonal -lactam (ceftazidime, cefepime, imipenem, meropenem, doripenem, or piperacillin/tazobactam) plus aminoglycosde or FQ (ciprofloxacin, levofloxacin) 2. Vacomycin or linezolid should be added to early onset regimen only if MRSA risk factors (e.g., history of MRSA infection or colonization, recent hospitalization or antibiotic use, presence of invasive health care devices) are present or there is a high incidence locally (greater than 10%-15%).

What is the empiric treatment for CAP in nonhospitalized patients that are previously healthy and have had no antibiotic therapy in the past 3 months?

Macrolide (clarithromycin or Azithromycin is H.influenza suspected) Doxycycline

CURB-65 scoring system

Measures the severity of illness for CAP patients

What is the empiric treatment for CAP in nonhospitalized patients with comorbidities (COPD, DM, renal or liver failure, CHF, malignancy, asplenia or immunosuppression) or recent antibiotic therapy (past 3 months)

Respiratory Fluoroquinolone (Moxifloxacin, Gemifloxaxin or Levofloxacin) Macrolide (or doxycycline) with high dose amoxicillin (1g three times/day) or augmentin (2g twice weekly) or a cephalosporine (Ceftriaxone, Cefuroxime, or Cefpodoxime)

How does the CURB-65 score determine the location of therapy?

Score of <2 = outpatient Score of 2 = Outpatient or inpatient Score >3 - Inpatient +/- ICU

What is ventilator-associated pneumonia (VAP)?

occurs more than 48-72 hours after endotracheal intubation

What is hospital acquired pneumonia (HAP)?

pneumonia occurs 48 hours or longer after hospital admission and not incubating at the time of hospitalization.