Paeds - Fever without a focus Flashcards
What is the difference between sepsis and septicaemia?
Septicaemia = when bacteria enter bloodstream, and cause blood poisoning which triggers sepsis
Sepsis = life-threatening physiological response to infection that causes systemic inflammation, organ failure and death
In which (adults or children) should symptoms of a UTI prompt an investigation for underlying causes / kidney damage?
Children
What are the common causative organisms of a UTI in children?
E. Coli ( ~ 80% of cases)
- Proteus
- Pseudomonas
What factors predispose children to developing a UTI?
- incomplete emptying
- infrequent voiding - resulting in bladder enlargement
- hurried micturition
- obstruction by full rectum due to constipation
- neuropathic bladder
- vesicoureteric reflux - abnormal backflow of urine from bladder into ureter / kidney (present in ~30% of children who present with UTI)
- poor hygiene - not wiping front to back in girls
Up till 3 months of age, UTIs are more common in which gender?
Males (due to more congenital abnormalities)
then it becomes substantially higher in girls past 3-months
How does a UTI present for the following age groups:
- Infants
- Children
Infants:
- Fever
- Poor feeding
- Vomiting
- Irritability
- Jaundice
- Offensive urine smell
- Febrile convulsions ( > 6-months old)
Children:
- Fever
- Dysuria
- Urinary frequency
- Abdo pain or loin tenderness
- Haematuria
- Vomiting
- Diarrhoea
- Constipation
- Lethargy
- Recurrence of enuresis
Dysuria without other symptoms is often due to
what in each of boys / girls?
Boys = balanitis (in uncircumcised boys)
Girls = vulvitis
In Infants what ways can be used to collect a urine sample?
- ‘Clean-catch’ (preferred) - sample into a waiting clean pot when nappy is removed
-
Urine collection pads - can be used if a clean-catch sample is not possible
- Never use cotton wool balls or gauze to obtain a sample
- Urethral catheter - if sample is urgent + no urine is being passed
- Suprapubic aspiration (SPA) /w ultrasound to confirm urine present in bladder - only to be used if non-invasive methods aren’t possible
How are UTI’s in children managed?
- < 3-months old –> immediate referral to hospital (require IV Abx e.g. cefotaxime)
-
> 3-months old + upper UTI –> consider admission to hospital
- if not admitted –> oral Abx for 7-10 days e.g. cephalosporin or co-amoxiclav
- > 3-months old + lower UTI –> oral Abx for 3 days e.g. trimethoprim, nitrofurantoin, cephalosporin or amoxicillin
Which 2 features on a Urine dipstick can be used to indicate whether a pt likely has a UTI?
Leucocyte esterase (+ve)
&
Nitrite (+ve)
For each of the following 4 urine dipstick results in a child what action do you take?
- Leucocyte +ve & Nitrite +ve
- Leucocyte -ve & Nitrite +ve
- Leucocyte +ve & Nitrite -ve
- Leucocyte -ve & Nitrite -ve
If the conclusion of a urine dipstick is that a UTI is likely then:
- Send a clean-catch sample (or other suitable sample) for M,C&S
- Start antibiotics whilst awaiting urine culture
What features are measured on a urine dipstick?
- Leucocyte esterase
- Nitrates
- Glucose
- Blood
- Protein
- Ketones
For each of the following aspects of a urine dipstick, if the result is abnormal what subsequent test might you suggest?
- Glucose
- Blood
- Protein
- Ketones
Glucose:
- Indicative of: Diabetes
- Action: Check blood glucose / HbA1C
Blood:
- Indicative of: Tumour, trauma or infection
- Action: if no indication or infection then USS urgent
Protein:
- Indicative of: Tubular or glomerular disease
- Action: Recheck, check Protein:Creatinine ratio
Ketones:
- Indicative of: Fat metabolism e.g. fasting as compensation of DKA
- Action: monitor or consider checking blood glucose
What are the hallmarks of nephrotic syndrome?
- Proteinuria ( > 3.5g / 24hrs, ++++ Protein dipstick, frothy urine)
-
Hypoalbuminaemia (< 30g/L)
- albumin lost in urine due to gaps in podocytes of glomerulus
-
Oedema
- albumin lost in urine –> ↓ intravascular oncotic pressure –> fluid moves into into surrounding tissues
-
Hyperlipidemia
- liver compensates for hypoalbuminaemia by ↑ production, but side effect is ↑ lipid production
Also you will see:
- Lipiduria
- Loss of immunoglobulins –> increased risk of infection
- Loss of antithrombin-III, proteins C and S (endogenous anticoagulants) –> increase thrombosis risk
Proteinuria can occur transiently for physiological reasons (non pathological),
name some instances where this can occur?
- Post-exercise (transient but can by up to 10g/day)
- Post-prandial (transient & thought to be due to insulins actions on podocytes)
- Febrile illness
- Orthostatic proteinuria (only when upright and not during early morning)
- Pregnancy
- High BP
What are the 4 main features of Nephritic Syndrome?
-
Haematuria (+++ Blood dipstick - microscopic or macroscopic)
- Possible ‘red cell casts’ = microscopic cylindrical structure, present in urine, produced in nephrons in diseased states
- Haematuria occurs due to gaps in podocytes of glomerulus
- Proteinuria (++ Protein dipstick = small amount)
- Hypertension (usually mild)
- Low Urine Volume (i.e. oliguria, < 300 ml/day) - due to ↓ renal function
Which has greater sensitivity for low levels of proteinuria;
Protein:creatinine ratio
OR
Albumin:creatine ratio
Albumin : Creatinine Ratio
Which method of monitoring proteinuria is recommended for diabetics;
Protein:creatinine ratio
OR
Albumin:creatine ratio
Albumin : Creatine ratio
What are normal values for:
- Adult PCR (Protein : Creatinine ratio)
- Child PCR (Protein : Creatinine ratio)
- ACR (Albumin : Creatinine ratio)
Adult PCR < 15 mg/mmol
Child PCR < 20 mg/mmol
ACR < 3 mg/mmol
Reminder: what is the classic triad of nephrotic syndrome?
How are the values for this triad different in children?
Nephrotic syndrome Triad:
- Proteinuria > 1 g/m2/24hrs (as opposed to > 3.5g/24hrs)
- Hypoalbuminaemia < 25 g/L (as opposed to < 30 g/L)
- Oedema
At what ages is nephrotic syndrome most common in children?
2 -5 years old
What are ~80% of Nephrotic Syndrome cases in children
due to?
Minimal Change Glomerulonephritis
~80% of childhood nephrotic syndrome
For the following, at what threshold do we diagnose Proteinuria?
- Protein : Creatinine ratio
- Albumin : Creatinine ratio
- Adult - PCR > 15 mg/mmol = proteinuria
-
Child - PCR > 20 mg/mmol = proteinuria
- PCR > 200 mg/mmol = nephrotic range
- ACR > 30 mg/mmol
Which protein is secreted by renal tubules up to 150 mg/day
and forms the boundary for the normal level of protein in urine
(<150 mg/day)?
Tamm-Horsfall Glycoprotein (THP) also called Uromodulin
- > 150 mg/day = proteinuria –> suggests ↑ glomerular permeability
- This protein is not tested for by urine dipstick (which usually tests for albumin)
What is the commonest cause of nephrotic syndrome in adults?
Membranous Nephropathy / Membranous Glomerulonephritis
What can cause Minimal Change Glomerulonephritis (MCG)?
Most cases = Idiopathic!!
10-20% of cases due to:
- Drugs: NSAIDs, rifampicin
- Hodgkin’s lymphoma or thymoma
- Infectious mononucleosis (glandular fever)
What are the features of MCG?
-
Nephrotic syndrome
- Hyperproteinuria is selective i.e. only intermediate-sized proteins such as albumin & transferrin leak through the glomerulus
- Normal BP (HTN is rare)
- Renal biopsy:
- Normal glomeruli on light microscopy
- Electron microscopy shows fusion of podocytes + flattening of foot processes