Common Diseases and Antibiotics

1. Common Diseases and Antibiotics William Bortcosh, MD

2. Introduction • Lectures are boring • Let’s jump right into questions!

3. Case #1 A 7-year-old female presents with a complaint of cough. Her mother reports that she has had a runny nose and cough for one day. Her skin felt “hot hot” today, so she came to the hospital to see you. On examination her temperature is 101° F, her heart rate is 90, her respirations are 25 breaths per minute, her blood pressure is 100/70, and her oxygen saturation is 99% on room air. She is alert and playful. She has clear rhinorrhea and injected nasal mucosa. You hear inspiratory rhonchorous sounds bilaterally. What do you want to do? • Give chloramphenicol • Give ampicillin and gentamicin • Give artesunate followed by ACTs • Give ampicillin/cloxacillin combination drug • Do nothing

4. Case #1: A. Chloramphenicol WRONG! You give the patient chloramphenicol. She develops aplastic anemia and dies.

5. Case #1: B. Ampicillin and Gentamicin WRONG! This patient did not have a pneumonia. She develops acute kidney injury and ends up staying in the hospital for a total of 21 days.

6. Case #1: C. Artesunate and ACTs WRONG! This patient did not have malaria. Your patient develops a new fever after initiating the ACTs. She was hospitalized for 3 days to search for a cause for the fever. (insert image)

7. Case #1: D. Ampicillin/Cloxacillin WRONG! This patient had an upper respiratory infection. Your patient spends a lot of money on unnecessary antibiotics. (insert picture

8. Case #1: E. Do nothing CORRECT! This patient has an upper respiratory infection (URI). This is most commonly caused by viruses (insert pictures of viruses). An upper respiratory infection will resolve spontaneously usually within 7-14 days. Viruses are the cause of upper respiratory tract infections. These resolve with supportive care if the immune system is competent.

9. Pneumonia versus URI You can clinically differentiate between a pneumonia and an upper respiratory infection. Fever and cough can occur in both a pneumonia and a URI. Patients with a lower respiratory tract infection such as pneumonia are often tachypnic. If a patient has fever, cough, and tachypnea, one should be concerned for a pneumonia regardless of sounds auscultated on the respiratory examination.

10. Upper and Lower Respiratory Tracts

11. Case #2: A 6-year-old male presents to you in the emergency department. He felt “hot hot” for four days. He had a cough that started three days prior. On examination his temperature is 101° F, his heart rate is 110, his respirations are 48 breaths per minute, his blood pressure is 95/70, and his oxygen saturation is 93% on room air. He is uncomfortable appearing lying on the table. He does not have rhinorrhea. You hear inspiratory crackles on the right side more than the left. What do you want to do? • Give ceftriaxone and admit to the hospital • Give metronidazole and admit to the hospital • Give high-dose amoxicillin and discharge home if drinking well • Give erythromycin and discharge home if drinking well • Do nothing

12. Case #2: A. Ceftriaxone and admit WRONG! You give the patient ceftriaxone and admit to the hospital. The patient gets better, but he stays 7 days longer than he had to!

13. Case #2: B. Metronidazole and admit WRONG! You give the patient metronidazole and admit to the hospital. The patient get worse, and your attending hits you with a rolled up newspaper for choosing the wrong antibiotic.

14. Case #2: C. Amoxicillin and discharge home Correct! This patient has clinical features consistent with a pneumonia (fever, cough, tachypnea, and chest exam findings) but is also hemodyamically stable. If he is able to adequately hydrate, he can go home on oral medicine.

15. Pneumonia Common Organisms • Viruses commonly cause lower respiratory tract infections • Lobar pneumonia (single lobe pneumonia) • Streptococcus pneumonia (resistant to low-dose amoxicillin) • Haemophilusinfluenzae(sometimes resistant to amoxicillin; susceptible to beta-lactamase inhibitors, e.g. amoxicillin-clavulanate) • Atypical pneumonia (bilateral, diffuse infiltrates in well-appearing patient) • Mycoplasma pneumonia • Legionella pneumonia (often associated with diarrhea, uncommon in children) • Severe pneumonia (bilateral infiltrates, hemodynamically unstable) • Staphylococcus aureus(requires anti-staphylococcal antibiotics) • Pseudomonas (patient is often immunocompromised) • Neonates (primary organisms are streptococcus, E. coli, and Listeria, all of which are susceptible to ampicillin and gentamicin)

16. Case #2: D. Erythromycin and discharge home WRONG! You give the patient erythromycin and discharge them home. They develop diarrhea, and their pneumonia fails to improve.

17. Case #2: E. Do Nothing WRONG! You decide to go take a lunch break, and the patient goes home without treatment. You are implicated in a lawsuit for malpractice.

18. Case #3: A 1-year-old male presents to you in the outpatient department. His mother tells you that he felt “hot hot” today. He had a cough and runny nose that started two days prior. On examination his temperature is 101° F, his heart rate is 110, his respirations are 36breaths per minute, his blood pressure is 90/65, and his oxygen saturation is 99% on room air. He appears irritable in his mother’s arms. He has clear rhinorrhea and yellow drainage from his left ear. His lungs are clear to auscultation without adventitious sounds. What do you want to do? • Give ceftriaxone and admit to the hospital • Give co-trimoxazole and discharge home • Give high-dose amoxicillin and discharge home if drinking well • Give high-dose amoxicillin, ciprofloxacin ear drops, and discharge home if drinking well • Give chloramphenicol and discharge home with a hemoglobin check scheduled in one week

19. Case #3: A. Ceftriaxone and admit WRONG! You give the patient ceftriaxone and admit to the hospital. The patient gets better, but you are fired from your job for admitting a patient who could have been discharged home. You spend the rest of your life as an auto-mechanic.

20. Case #3: B. Co-trimoxazole and discharge home WRONG! The patient’s ear infection seems to go away after about a week, but he develops mastoiditis and a subsequent brain abscess.

21. Case #3: C. Amoxicillin and discharge WRONG! The patient’s ear pain lingers for another week before a different clinician places the patient on antibiotic ear drops.

22. Case #3: D. Amoxicillin, ciprofloxacin ear drops, and discharge Correct! This patient had an otitis media with an associated tympanic membrane rupture. The ear canal does not have good perfusion, and oral antibiotics often do not reach that area in the desired quantity. Thus, if there is a rupture, many physicians prescribe both oral antibiotics for the middle-ear infection and oral antibiotics for the associated cellulitis of the ear canal. Two of the three of the following must exist to diagnose an otitis media: inflammation (e.g. fever), otalgia (i.e. ear pain), and otorrhea (i.e. ear drainage).

23. Pathophysiology • The Eustachian Tube, connecting the middle ear to the posterior oral cavity, functions to maintain an equal pressure on both sides of the tympanic membrane as well as to allow fluid and bacteria to drain from the middle ear • Eustachian Tube dysfunction, which may occur in the settings of infections or allergies, may result in buildup of fluid and bacteria behind the tympanic membrane, promoting infection

24. Etiology of Otitis Media • Most ear infections are caused by viruses and are thus self-limited • RSV, rhinovirus, coronavirus, parainfluenza, adenovirus, enterovirus • Likely bacterial pathogens include: • Streptococcus pneumoniae • Hemophilusinfluenzae • Moraxellacatarrhalis

25. Otitis Media • Common organisms in otitis externa (infection of the ear canal) • Pseudomonas (susceptible to ciprofloxacin and other certain antibiotics) • Polymicrobial

26. Amenable Risk Factors • Daycare attendance • Lack of breastfeeding for at least 6 months • Supine bottle feeding • Pacifier use after 6 months of life • Exposure to tobacco smoke • Vaccination (Influenza and H. influenzae)

27. Antibiotic Coverage

28. Case #3: E. Chloramphenicol and follow-up You give the patient chloramphenicol, and he has not improved at his one week follow-up (although his hemoglobin is fine). Your attending prescribes the appropriate antibiotics and punishes you.

29. Case #4: A 10-year-old female presents to you in the emergency department. She has had abdominal pain around her umbilicus for 2 days, and now the pain is in her right lower quadrant. She has felt nauseous and has vomited two times in the past 2 days. She has not passed stool since yesterday. She has felt “hot hot” since yesterday. On examination her temperature is 102° F, her heart rate is 110, his respirations are 32 breaths per minute, his blood pressure is 100/70, and his oxygen saturation is 99% on room air. She is uncomfortable appearing lying on the table. Her lung exam reveals crackles at the bases bilaterally. Her abdomen is firm and diffusely tender. What do you want to do? • Send the patient to surgery and start ciprofloxacin and metronidazole • Send the patient home on ciprofloxacin and metronidazole • Send the patient to surgery and start ampicillin and gentamicin • Send the patient home on amoxicillin and gentamicin • Send the patient home on chloramphenicol

30. Case #4: A. Surgery, ciprofloxacin, and metronidazole Correct! This patient had an appendicitis. Differential diagnosis includes typhoid perforation and small bowel obstruction. Obstruction of the appendix, often with a fecolith, leads to inflammation, swelling, and eventual perforation. Clinical findings suggestive of appendicitis include abdominal pain with migration from the umbilicus to the right lower quadrant, pain pain with percussion or hopping, fever, vomiting, tenderness at McBurney’s point, Rosving’s sign, Psoas sign, and Obturator sign.

31. Appendicitis • Common organisms • Enteric gram negatives (e.g. Enterobacter) • Anaerobes (e.g. Bacteroidesfragilis)

32. Antibiotic Coverage

33. Case #4: B. Discharge home with ciprofloxacin and metronidazole WRONG! The patient initially feels better, but then starts spiking fevers. She becomes septic and dies due to an abdominal abscess.

34. Case #4: C. Surgery, ampicillin, and gentamicin WRONG! The patient tolerates the surgery well, but she continues to spike fevers post-operatively. The surgeons round one week later and yell at you for choosing the wrong antibiotics.

35. Case #4: D. Discharge home with amoxicillin and gentamicin WRONG! The patient initially feels better, but then starts spiking fevers. She is readmitted and is diagnosed with a perforated appendicitis with associated intraabdominal abscesses.

36. Case #4: E. Discharge home with chloramphenicol WRONG! The patient initially feels better, but then starts spiking fevers. She is readmitted and is diagnosed with a perforated appendicitis with associated intraabdominal abscesses.

37. Case #5: A 2-year-old male presents to you in the emergency department. He felt “hot hot” yesterday, and he had some jerking last night. Today when he woke up he was unresponsive. On examination his temperature is 104° F, his heart rate is 140, his respirations are 50 breaths per minute, his blood pressure is 90/70, and his oxygen saturation is 97% on room air. He has a GCS of 3. He is making sucking movements with his mouth. You cannot bend his neck to his chest. He resists flexion of his hips. What do you want to do? • Admit the patient and start ampicillin and gentamicin • Admit the patient and start ceftriaxone • Admit the patient and start co-trimoxazole • Send the patient home on chloramphenicol • Send the patient home with your best wishes

38. Case #5: A. Ampicillin, gentamicin, and admit WRONG! You give the patient ampicillin, gentamicin and admit him to the hospital. The patient dies the following morning. You remember that these medications do not have good CNS penetration due to the blood brain barrier!

39. Case #5: B. Ceftriaxone and admit Correct! You give the patient ceftriaxone and admit to the hospital. His fevers resolve, although he is left with a severe neurologic deficit. You support the family as best possible.

40. Meningitis • Pathophysiology • Inflammation of the meninges surrounded the brain and spinal cord, often from hematogenous spread • Clinical features • Fever, altered mental status, stiff neck (if older than 1 year), cranial nerve palsies (specifically abducens nerve palsy is common), seizures, Kerdnig and Brudzinski signs • Diagnosis • Clinical/laboratory (CSF: high WBC, low glucose, high protein)

41. Meningitis • Common organisms • Neonatal (GEL) • Group B streptococcus (susceptible to ampicillin) • E. coli (susceptible to ampicillin and gentamicin) • Listeria (susceptible only to ampicillin) • 2-12 months • Streptococcus pneumonia • Haemophilus influenza • E. coli • Staphylococcus aureus • In older children, also consider Neisseria meningitides, which is associated with purpura

42. Meningitis – Key Points • Ampicillin and gentamicin are appropriate in neonates for treatment of meningitis because of their incompetent blood-brain barrier • In older children, ceftriaxone is required to penetrate the blood brain barrier in adequate concentrations • Studies have shown that steroids are useful in meningitis caused by Neisseria meningitides (to decrease mortality) or Haemophilus influenza (to decrease risk of hearing loss)

43. Case #5: C. Co-trimoxazole and admit WRONG! You give the patient co-trimoxazole and admit to the hospital. The patient acutely decompensates, but he is resuscitated and started on the appropriate antibiotics. You are forced to work weekends for the next three months as punishment.

44. Case #5: D. Chloramphenicol and home WRONG! You give the patient chloramphenicol and discharge him home with the parents and your best wishes. He recovers surprisingly well, but you are fired from your job for negligence.

45. Case #5: E. Give you best wishes and send home WRONG! Really? That’s the answer you’re going to choose? Try again.

46. Case #6: An 8-year-old female presents to you in the outpatient department. She complains of burning with urination. She has been urinating more frequently. On examination her temperature is 99° F, her heart rate is 110, her respirations are 24 breaths per minute, her blood pressure is 100/70, and her oxygen saturation is 99% on room air. Her exam is unremarkable. What do you want to do? • Urine dipstick and start co-trimoxazole if positive • Urine dipstick and start chloramphenicol • Urine dipstick and start metronidazole • Urine dipstick and start erythromycin • Admit the patient for further evaluation

47. Case #6: A. Urine dipstick and co-trimoxazole Correct! This patient has a urinary tract infection (UTI), likely cystitis. A urine dipstick is important to confirm or disprove the presence of a UTI, and then the patient should be placed on an appropriate antibiotic for 5 to 7 days.

48. Urinary Tract Infection • Pathogenesis • Urinary tract infections are caused by the ascension of normal perineal flora up the urethra and to different portions of the urinary tract. Infection of the bladder is called “cystitis,” and infection of the kidney is caused “pyelonephritis” • Risk Factors • Female (more likely due to shorter urethra than males) • <2 years of age • Caucasian • Clinical features • Dysuria, frequency, nocturia; if fever or flank tenderness is present, these imply pyelonephritis

49. Urinary Tract Infection

50. Urinary Tract Infection • Common Organisms (SEEKS PP) • Streptococcus (group B) • E. coli • Enterobacter • Klebsiella • Serratiamarascens • Pseudomonas aeruginosa • Proteus mirabilis • Gram negative coverage is essential! • Treatment • 5 to 7 days of an appropriate antibiotic, which include co-trimoxazole, amoxicillin (in some cases), oral cephalosporins, and others