Infections – Part 1

1. Infections – Part 1 • In patients with a suspected infection • Determine the correct tools (eg. swabs, culture/transport medium), techniques and protocols for cultures • Culture when appropriate (eg. thraot swabs/sore throat guidelines). • When considering treatment of an infection with an antibiotic, do so • Judiciously (eg. delayed treatment in otitis media) • Rationally (eg. cost, guidelines, comorbidity, local resistance patterns) • Treat infections empirically when appropriate (eg. life threatening sepsis without culture reported or confirmed diagnosis, candida vaginitis post-antibiotic use) • Look for infection as a possible cause in a patient with an ill defined problem (eg. failure to thrive, unexplained pain [necrotizing fasciitis], abdominal pain in children with pneumonia) • When a patient returns after an original diagnosis of a simple infection and is deteriorating or not responding to treatment, think about and look for more complex infection (i.e. Don’t assume the infection is just slow to resolve) • When treating infections with antibiotics, use other therapies where appropriate (eg. aggressive fluid resuscitation in septic shock, incision and drainage for abscess, pain relief)

2. Case 1 • Elise is a 6 year old who presents to your office with a 2 day history of fever, malaise, mild abdominal pain and sore throat. On examination, she looks generally well, but her temperature is 38.4. Other VSS. She has erythematous enlarged tonsils and a strawberry tongue with some cervical lymphadenopathy in the anterior cervical chain. • Question 1: How do you diagnose her?

3. Pharyngitis Streptococcal Viral Rapid onset Headache, abdo pain, fever Enlarged, erythematous tonsils Petechiae, adenopathy Systemic signs (Scarlet fever) – circumoral pallor, Pastia’s lines, strawberry tongue Slower onset Coryza, conjunctivitis, cough Enlarged, erythematous tonsils Ulcerations (eg. enteroviruses Systemic signs (Infectious mononucleosis) – hepatomegaly, fatigue,etc

4. Diagnosis pharyngitis • Throat swab • False positives – • Organism misidentified as GABHS • Chronic GABHS carrier • False negatives • Poor technique • Patient using antibiotics • Rapid strept antigen test • Very specific, but less sensitive • Send culture to confirm negative result • A word on technique • Position: Neck extended, tongue protruded and depressed • Reassurance: May cause gagging, coughing. May require restraint • Anatomy: Swab tonsillar arches. Avoid sides of mouth

5. Case 1 (continued) • Elise is a 6 year old who presents to your office with a 2 day history of fever, malaise, mild abdominal pain and sore throat. On examination, she looks generally well, but her temperature is 38.4. Other VSS. She has erythematous enlarged tonsils and a strawberry tongue with some cervical lymphadenopathy in the anterior cervical chain. • Question 2: Her throat swab is positive for group A streptococcus. What is your treatment plan?

6. Wrong Answer

7. Treatment of pharyngitis • Most resolve uneventfully in a few days • Antibiotic therapy hastens resolution and prevents development of rheumatic fever • Treat without culture if: • Positive rapid strept test • Scarlet fever • Household contact with documented strep pharyngitis • Past history of acute rheumatic fever • Recent history of acute rheumatic fever in family member • Penicillin is first choice (inexpensive, narrow spectrum, effective) • Use macrolide in anaphylactic allergy to penicillin • May use 1st generation cephalosporin (eg. cephalexin) in non type 1 allergy • Treat the pain • Gargling with salt water • Acetaminophen

8. Case 1 (continued) • Elise returns two weeks later with a similar episode and has a rapid test positive for strep. • Question 3: What must you consider in treating her? • Answers: • Possible resistant organism • Possible reinfection with different strain • Possible viral pharyngitis with strep carriage • Consider immunologic abnormalities • Treatment to eliminate carriage (Clindamycin) • Tonsillectomy in >7 per year or >5 per year in past two years

9. Case 2 • Brayden is a three month old boy who is being seen in the ER. His mother says he has always been a fussy baby. They were seen by their family doctor who told his mother “It’s only colic”. He seemed to be getting better for the past month, but over the past week he is about as fussy as he has ever been. Your examination reveals a well appearing baby asleep in his mother’s arms after a breastfeed. The triage nurse did a bagged urine specimen which is positive for leukocytes and nitrites. • How do you interpret this result?

10. Urine cultures • UTI may be suspected on clinical grounds, but culture diagnosis is essential for confirmation and to direct therapy. • Accurate urine samples • Toilet trained children: • Mid stream urine • Clean introitus, retract prepuce • Children in diapers: • Catheter specimen • What is a positive culture? (NB. The urine that sits on the counter.....) • Treatment • Oral antibiotics (TMP-SMX) • Consider intravenous in certain circumstances (3rd gen cephalosporin or Amp&Gent) • Age (eg. under one month) • Clinical condition (eg. toxic appeareance, dehydration) • Ability to tolerate po antibiotics (i.e. Vomiting)

11. Case 3 • Lydia is a four year old in your office for a routine visit. She says she has had a cold for the past two weeks but has been otherwise well. Your examination reveals Mildly discoloured fluid behind both tympanic membranes • What is your treatment plan?

12. Possible Otitis Media • Certain diagnosis contains all of the following: • Recent (usually acute) onset of illness • Presence of MEE • At least two signs of middle ear inflammation • Discoloration • Opacification not due to scarring • Decreased/absent mobility • Important to distinguish AOM from OME! • Distinct fullness or bulging of the TM (bagel without a hole) • Clinically important ear pain • Erythema alone does not distinguish • OME in absence of acute infection does not require antibiotic therapy!

13. Possible Otitis Media • Situations in which a period of watchful waiting may be appropriate: • Over 2 years of age with certain or uncertain diagnosis • Age 6-24 months with uncertain diagnosis • Excluding children with craniofacial anomalies • Excluding children with severe disease • Fever >39 • Severe otalgia • Toxic appearance • Patient should be reassessed in 48-72 hours • Parents must be able to know if child is deteriorating

14. Case 3 • Eric’s parents have brought him to the ER tonight as he is “just not himself”. He is an eleven month old boy that is usually playful and happy, but over the day he has had a fever and has been quite fussy. Tonight, his parents describe him as “lethargic”. He has been previously well and has had all his vaccinations. On examination, he is a fussy child who doesn’t fully console in his parents arms. He looks tired, hypotonic and has mottled skin. He demonstrates effortless tachypnea with a resp rate of about 60. His heart rate is 180 with no murmur and his blood pressure 88/50. He is noted to have a petechial rash over both of his feet. • What is your initial assessment? • What are your treatment priorities?

15. Case 3 • What is your initial assessment? • Compensated shock, likely septic shock • What are your treatment priorities? • Stabilize ABCs • Monitored setting; call for help • Ensure maintaining airway • 100% oxygen • Establish iv access and begin fluid resuscitation • Obtain blood and urine cultures • Start empiric antibiotic therapy

16. Septic Shock • Approximately 7% of childhood deaths • Sepsis-associated mortality in young infants dropped from 97% in 1960s to 9% in 1990s • Definition of septic shock requires two components: • Shock – Inability of body to adequately perfuse organs • Sepsis – SIRS criteria with an infectious source

17. Investigation of Septic Shock • CBC (leukopenia/leukocytosis, platelet count) • Blood culture • Coagulation function, D-dimer, fibrinogen • Blood type and crossmatch • Chemistry (Acidosis) including lactate • Urinalysis & culture • CSF analysis and culture • CXR if any findings in chest • CT Abdo if concern for intra-abdominal surgical focus

18. Management of Septic Shock “The Golden Hour” • Stabilize Airway/Breathing • High flow oxygen • Regardless of sats • Use a non-rebreather mask if possible • Consider intubation & ventilation • Up to 40% of cardiac output used for work of breathing • Ketamine drug of choice for RSI • Stabilize circulation • Early and aggressive fluid resuscitation • 20ml/kg boluses, aiming for 60ml/kg in the first 15 minutes (10ml/kg for neonates) • Use of intropes if fluid refractory shock • Dopamine still firstline in children • Next use epinephrine or norepinephrine in “warm shock”

19. Management of Septic Shock “The Golden Hour” • Treat underlying focus of infection • Draw cultures & Start broad spectrum antibiotics • Do not delay treatment waiting for cultures • Treat associated complications • Adrenal insufficiency • Hypoglycemia • Hypocalcemia

20. Other tidbits • Kids are often harder to get cultures (non-compliant) • Typically only get one aerobic culture • Young children at higher risk for bacterial infection • Remember per kilogram dosing of antibiotics • LOOK IT UP! • Limited data on pharmacokinetics of antibiotics in children • Avoid tetracyclines in children under age eight (dental staining) • Avoid fluoroquinolones due to concerns re: arthropathy