E-learning: Diagnosis + Management Of Common +/- Serious Infection Flashcards
Antibiotic use
- Defervescence: sign of under control infection (NOT how severely patient is still coughing)
- Antibiotic take 48 hours to work (exceptions: typhoid fever, TB, necrotising pneumonia, empyema, abscess)
- Emergency antibiotic stock: Meropenem, Tazocin, Levofloxacin, Amikacin, Vancomycin
- Other supportive therapy may be needed
- Taper according to sensitivity
Pneumonia
- Typical bacteria vs Atypical bacteria vs Viral vs TB —> by History of duration / Acuteness
- Fever + Cough starting with Runny nose —> more likely viral
- Presence of viral infection NOT rule out superimposed bacterial infection
P/E + Radiologic findings:
- Lobar (consolidation) —> Bacterial more likely
- Interstitial —> Viral / Mycoplasma more likely
- Effusion —> Pneumococcus, Mycoplasma, TB (Viral unlikely)
CBC:
- Neutrophilia —> Bacterial more likely
- Normal WBC + Lymphopenia / Neutropenia —> Viral
- Normal WBC —> Viral / Mycoplasma
- Low WBC —> Beware of overwhelming bacterial infection
Treatment:
- Typical bacterial (Strept pneumoniae, H. influenzae, M. catarrhalis): Augmentin
—> Septic looking / Parapneumonic effusion —> IV Cefotaxime / Ceftriaxone
—> No reason for IV Vancomycin empirically
- Mycoplasma: Clarithromycin (if not work —> Doxycycline (>8 yo), Levofloxacin (<8 yo))
- Viral: No antibiotic unless superimposed bacterial infection e.g. new fever, consolidation, neutrophilia
- Influenza A / B: Oseltamivir (Tamiflu) probably not needed in mild disease (beware SE of vomiting, neuropsychiatric behaviours e.g. suicide)
CXR:
- Repeat if progressive deterioration
- No need FU CXR after treatment if uncomplicated pneumonia
- Repeat 4-6 weeks later if
—> Recurrent pneumonia with same lobe
—> Lobar collapse with suspicion of anatomic anomaly
—> Chest mass
—> Foreign body aspiration
Acute otitis media
Causative agents:
- Viral
- Mixed Viral + Bacterial (Pneumococcus, H. influenzae, M. catarrhalis)
P/E:
- Red tympanic membrane
- Light reflex gone (inflammation + effusion)
Treatment:
- Amoxicillin / Augmentin 10 days (Spontaneous resolution rate: 66-80%)
- Recheck tympanic membrane in 2 months (effusion can take up to 3 months to resolve, if still present at 3 months, refer ENT for drainage)
Meningitis
S/S:
- Fever
- Bulging anterior fontanelle
- Neck stiffness (anterior flexion (NOT L/R flexion))
- Headache
- Seizure
Bacterial meningitis:
- CSF: Leukocytosis with neutrophil predominance, Low glucose, High protein
- Strept pneumoniae, N. meningitidis, H. influenzae type B
- E. coli usually in context of urosepsis from UTI (urinary tract —> blood —> meninges)
- IV 3rd gen Cephalosporin + IV Vancomycin (cover for potential 3rd gen cephalosporin resistance pneumococcus)
Viral meningitis:
- CSF: Leukocytosis without neutrophilia, Lowish glucose, High protein
- Enterovirus, HSV (esp. if bloody with high RBC + high protein) —> send CSF for HSV + EV PCR
- IV Acyclovir for HSV
TB meningitis:
- CSF: Leukocytosis without neutrophilia, Very low glucose, High protein
- Isoniazid, Rifampin, Ethambutol, IV Amikacin
- No need for Pyridoxine
- Consider steroid (inflammatory response once TB is killed)
Urinary tract infection
- NOT test for UTI in children with obvious RTI unless special reason
- Bag urine / MSU for urinalysis first if not toxic (i.e. you can wait)
- Never send Bag urine for culture —> Catheterised urine / Clean catch MSU
- Ascending infection from stool flora that colonise the perineum
—> Enterobacteriaceae (E. coli, Klebsiella)
—> Significant incidence of ESBL producing Enterobacteriaceae resistant to Cephalosporins
—> Susceptible to Augmentin now
Treatment:
- Oral Augmentin (standard dose)
- IV Meropenem (for septic looking patients (send blood culture))
Monitoring:
- Elective renal USG
- MCUG (voiding / micturating cystourethrogram) if the 1st febrile UTI accompanied by >=1 risk factors:
1. Severe sepsis / proven septicaemia
2. Palpable abdominal mass
3. Impairment of baseline RFT
4. History of abnormal urine stream
5. UTI due to non-E. coli organisms
6. No clinical response to appropriate antibiotic treatment within 48 hours
7. VUR in 1st degree relative
Urinary tract infection (UTI) in Paediatrics (SpC Paed UTI: Dr. Christy Mak Junior Tutorial)
Epidemiology:
- ~3-7% boys + 1-2% >=1 episode <6 yo
- 12-30% recurrence in 1 yr
- 50% have structural abnormality
Causes:
1. Urinary stasis
- Vesicoureteric Reflux (VUR)
- Obstruction: Mechanical (loaded rectum / impacted faeces), Neuropathic
- Dysfunction
2. Stones
3. Ascending (Bubble-bath)
Causative agents (bowel flora):
- E. coli > Klebsiella > Proteus > Pseudomonas > Strept faecalis
- Proteus in boys esp. as colonised in prepuce (predisposes to phosphate stone, from splitting of urea to NH3 —> alkalising the urine)
- Pseudomonas esp. in structural abnormality
Clinical features:
Infant / Young child:
1. Non-specific: Fever, Appetite, Lethargy, Vomiting
- Often just present as FEVER with NO localizing signs
2. Foul smelling urine / blood stain on diaper
3. Jaundice (inability to get rid of bilirubin esp. during NNJ)
4. Febrile convulsion
5. Septicaemia
Older child:
1. Specific Urinary Sx (e.g. Dysuria, Frequency, Urgency, Haematuria) (vs Dysuria in vulvitis, balanitis)
2. Others: Fever (may imply Pyelonephritis), Abdominal pain, Vomiting, Diarrhoea
3. Recurrence of enuresis
P/E:
- Abdominal Mass
- Bladder
- External Genitalia
- Sacrum
Diagnosis:
1. S/S
2. Urinalysis result
3. +ve Culture
Investigations:
1. Urinalysis
- ALL infants with unexplained fever >38oC
Bag urine: Screening + Urinalysis, Help rule out UTI but never sufficient for Dx
- Dipstick: leukocyte esterase, nitrite
- Microscopy: pyuria (WBC +ve also in balanitis / vulvitis)
—> ANY +ve —> Confirmatory tests (Culture)
Confirmatory:
- Clean-catch urine: Difficult in young infants (Parents may still try if insist)
- Catheterised urine: 10^4 CFU
- Suprapubic aspiration (Gold standard, but often considered too Invasive)
- Imaging in FU for Causes / Complications
- USG
—> Routine for ALL <2yo (detect possible stones, nephrocalcinosis, UT dilatation)
—> Elective for congenital renal abnormality, hydronephrosis, etc.
—> Urgent if suspect renal abscess, e.g. NOT responding to empirical abx
-
MCUG / VCUG (Micturating / Voiding cystourethrogram)
—> Detect VUR
—> Prophylactic cover with cefuroxime (Zinnat) on D-1, DO, D1 needed
—> Indications:
QMH Manual:
<3 yo: - Abnormal renal bladder USG
- Recurrent UTI
- Atypical UTI
—> Seriously ill / Septicaemia
—> Poor urine flow
—> Abdominal / bladder mass
—> Raised Cr
—> Failure to respond to suitable Abx
—> Infection w/ NON E coli organisms
>3yo: NOT indicated -
DMSA (99Tm DiMercaptoSuccinic Acid) scan = Static scan
—> 4-6 months after Infection (avoid “FALSE scar”)
—> Check renal parenchyma, scarring, function
—> Indications: - All boys <3 yo
- Girls <3 yo:
—> VUR grade 3-5
—> Recurrent UTI
—> Atypical UTI - > 3 yo: Recurrent UTI
-
MAG3 / DTPA scan: Exo/Dynamic scan (NOT usually done unless under specific circumstances)
—> MAG3 (MercaptoAcetyl Triglycerine) scan: Renal tubules, Drainage, Function
—> More preferred in (esp. Infant <2 y) than DTPA scan
—> MAG3 is excreted by proximal tubules (vs DTPA excreted via glomerular filtration) + Renal tubules mature faster than Glomeruli —> MAG3 extraction fraction is better
—> DTPA (Diathylene Triamine Pentaacetic Acid) scan: Glomerular filtration, Drainage
Management:
Principles:
1. NO need admission if child is well + >4 months
2. Clinically Upper UTI if fever >38oC or loin pain / tenderness
3. Identify G6PD (for Septrin)
- Empirical antibiotics
- <3 months / seriously ill: IV 2nd / 3rd gen Cephalosporin / Aminoglycoside
- >3 months: PO Augmentin for 7-10 d (as S/E of Augmentin) (3 d if dysuria ONLY)
- Oral NOT tolerated: IV for 2-4 d before switching to PO (total course = 10 d)
- Same dose conversion from oral to IV - General advice
- High fluid intake
- Regular voiding
- Double micturition
- Prevent constipation
- Good perineal hygiene
(- Lactobacillus acidophilus: reduce invasive gut organisms colonisation) - Prophylaxis
- Recommended for structural abnormality / VUR grade >=3: Trimethroprim 2mg/kg nocte
- Avoid broad spectrum antibiotics
- Considered for in VUR grade 1-2 or Recurrent UTI without VUR
Recurrent UTI / Scarring:
1. Urine culture x Any non-specific illness (routine)
2. Consider circumcision
3. Anti-reflux surgery (if VUR —> progressive scarring), i.e. reimplantation or injection of bulking agents = Deflux surgery
- NO evidence for outcome improvement
4. Annual BP (in all renal defects)
5. Regular assessment of renal growth + function (if Bilateral scarring due to risks of CRF)
Definition of Recurrent UTI:
- >=2 episodes of UTI with acute PN / upper UTI
or
- 1 episode of UTI with acute PN / upper UTI + >=1 episode of cystitis / lower UTI
or
- >=3 episode of UTI with cystitis / lower UTI
Definition of Seriously ill:
1. Unable to arouse / if aroused does not stay awake
2. Weak high-pitched / continuous cry (not consolable)
3. Pale / Mottled / Blue / Ashen
4. Reduced skin turgor
5. Bile-stained vomiting
6. Moderate / Severe chest indrawing
7. RR >60/min
8. Grunting
9. Bulging fontanelle
10. Appearing ill to a healthcare professional
11. Infants <3 months with >38oC and infants 3-6 months with >39oC
Staph. aureus, Strep. pyogenes
Cervical adenitis:
- Infection of LN
- NOT reactive adenopathy (draining an infection elsewhere)
- Acute, febrile, unilateral, red, hot, painful
- Neutrophilia
- If not responsive to appropriate antibiotics after 2 days —> consider Kawasaki, Kikuchi
Skin infections:
- Staph. aureus, Strep. pyogenes common coloners
- Cellulitis, necrotising fasciitis, abscess, phlebitis, infected eczema, boils etc.
- Exception: Perirectal abscess: Staph common but mixed with coliforms + anaerobes —> Tazocin +/- Metronidazole
Osteomyelitis + Septic arthritis
Treatment for all above:
- IV Cloxacillin (NOT oral) / IV Cephalothin (osteomyelitis, septic arthritis, and other infections if severe / not responsive to oral drug)
- Oral Cephalexin (Augmentin works but too broad coverage)
- Do NOT use Vancomycin unless proven MRSA (and not CA-MRSA)
Necrotising fasciitis
- Usually in context of broken skin e.g. Varicella (esp. with no bathing)
- On an extremity in paediatrics
- Need to rule out if considering Cellulitis
- Tenderness out of proportion with redness
- Medical + Surgical emergency
—> Rapid progression to Toxic shock syndrome (Toxin-mediated)
—> Urgent debridement + Relieve compartment syndrome
—> Call ICU + Ortho
—> IV Cloxacillin + IV Clindamycin (to block toxin), IVIG
—> (IV Vancomycin from emergency stock)
Fever + Neutropenia
- NOT same as oncology patients with neutropenia
—> Fever with no focus
—> Gram -ve bacteraemia translocated from GI tract
—> Need to kill them rapidly due to immunocompromised state - Most common in paediatric is associated with viral infection (e.g. RTI, roseola) + found neutropenic
—> Neutropenia a sequalae of viral infection
—> NO need empirical antibiotic
—> NO need to FU to recheck if patient had previous normal neutrophil count
—> Otherwise document normalisation esp. in young children since this may be incidental finding of chronic / cyclic neutropenia
—> If found in context of bacterial infection, think underlying chronic / cyclic neutropenia
Use of CRP, Blood culture
CRP:
- Monitor treatment response to deep-seated infection (e.g. fever gone but still wanna know whether infection controlled to determine treatment requirement)
Blood culture:
- NOT routine for all febrile children
- NOT send unless have a specific diagnosis in mind e.g. typhoid fever, bacteraemia
- Fever is the best indicator of persistent bacteraemia
—> Afebrile patients without new focal infections can be treated as outpatients with oral antibiotics
—> Febrile patients / Patients with new focal infection (e.g. meningitis) should undergo evaluation for sepsis + admitted for parenteral antibiotic
