Kidney and gastroenterology Flashcards
Calculation of eGFR
= (k * height (cm) ) / creatine (micro mol/L)
k = 31 or 40 (old Jaffe method)
Symptoms of UTI in infant
Nonspecific:
- Fever (usually present), febrile seizures
- Vomiting
- Lethargy or irritability
- Poor feeding/faltering growth
- Jaundice
- Septicemia - may develop rapidly
- Offensive urine
Symptoms of UTI in child
- Dysuria, frequency, and urgency
- Abdominal pain or loin tenderness
- Fever with or without rigors
- Lethargy and anorexia
- Vomiting, diarrhea
- Hematuria
- Offensive/cloudy urine
What can dysuria alone as a symptom indicate?
- Cystitis
- Vulvitis
- Balanitis (in uncircumcised boys)
Most common pathogens causing UTI
- E. coli
- Klebsiella
- Proteus (more common in boys)
- Pseudomonas
- Streptococcus faecalis
Causes of vesicoureteric reflux
- Familial (30-50% chance of occurring in first-degree relatives)
- Secondary to bladder pathology (neuropathic bladder, urethral obstruction)
- Temporary after a UTI
Causes of daytime enuresis
- Developmental or psychogenic
- Blader instability or neuropathy
- UTI
- Constipation
- Ectopic ureter
What is orthostatic proteinuria?
Proteinuria is only found when the child is upright during the day.
Causes of protienuria
- Orthostatic proteinuria
- Glomerular abnormalities
- Minimal change disease
- Glomerulonephritis
- Abnormal glomerular basement membrane
- Increased glomerular filtration pressure
- Reduced renal mass in chronic kidney disease
- HTN
- Tubular proteinuria
Main features of nephrotic syndrome
- Proteinuria
- Edema
- Low plasma albumin (<2,5 g/dL)
- Hyperlipidemia (loss of enzymes responsible of breakdown of cholesterol and lipids)
Clinical signs of nephrotic syndrome
- Periorbital edema (often the earliest sign)
- Scrotal or vulval, leg and ankle edema
- Ascitis
- Breathlessness - due to pleural effusion and abdominal distension
- Infection - peritonitis, septic arthritis, sepsis (loss of Ig in urine)
Nephrotic syndrome is often precipitated by …
respiratory infections
Features suggesting steroid-sensitive nephrotic syndrome
- Age 1-10 years
- No macroscopic hematuria
- Normal BP
- Normal complement levels
- Normal renal function
What is the most common nephrotic syndrome?
Steroid-sensitive minimal change disease
What is seen on the electron microscopy in steroid-sensitive nephrotic syndrome
Electron microscopy - fusion of the specialized epithelial cells that invest the glomerular capillaries (podocytes)
- Light microscopy usually normal
Complications in nephrotic syndrome
- Hypovolemia (during initial phase of edema formation)
- Thrombosis (urinary loss of antithrombin III, thrombocytosis, increased synthesis of clotting factors, increased blood viscosity)
- Infection (esp. pneumococcus)
- Hypercholesterolemia
Prognosis of nephrotic syndrome
1/3 - resolve directly
1/3 - infrequent relapses
1/3 - frequent relapses - steroid-dependent
What is often the earliest sign in nephrotic syndrome?
Periorbital edema
What is the most common steroid-resistant nephrotic syndrome?
Focal segmental glomerulosclerosis
Management of steroid-resistant nephrotic syndrome
- Treat edema - diuretics, salt restriction, ACEI
- Non-steroidal antiinflammatory drygs
- Genetic testing
Most common cause of hematuria?
UTI
Nonglomerular causes of hematuria
- Infection
- Trauma
- Stones
- Tumors
- Sickle cell disease
- Bleeding disorders
- Renal vein thrombosis
- Hypercalciuria
Glomerular causes of hematuria
- Acute glomerulonephritis (usually with proteinuria)
- Chronic glomerulonephritis (usually with proteinuria)
- IgA nephropathy
- Familial nephritis (e.g., Alport syndrome)
- Thin basement membrane disease
Types of steroid-resistant nephrotic disorders
- Focal segmental glomerulosclerosis
- Membranoproliferative glomerulonephritis
- Membranous nephropathy
Main features of acute nephritis
- Decreased urine output and volume overload
- Hypertension - may cause seizures
- Edema, initially periorbital
- Hematuria and proteinuria
Causes of acute nephritis
- Post-infectious (including streptococcus)
- Vasculitis (Henoch-Schonlein purpura, SLE, Wegener granulomatosis, microscopic polyarteritis, polyarteritis nodosa)
- IgA nephropathy and mesangiocapillary glomerulonephritis = membranoproliferative
- Antiglomerular basement membrane disease (Goodpasture syndrome)
Titres in post-streptococcal nephritis
- Raised Antistreptolysin O/anti-DNAse B titres
- Low complement C3 levels
Common features in Henoch-Schonlein purpura
- Characteristic skin rash on extensor surfaces
- Arthralgia
- Periarticular edema
- Abdominal pain
- Glomerulonephritis
Characteristics of the rash in Henoch-Schonlein purpura
- Symmetrically distributed
- Buttock, the extensor surfaces of the arms, legs and ankles
- Trunk is usually spared
- Initially urticarial –> maculopapular and purpuric
- Palpable
- Rash is first clinical features in about 50%
Clinical features in Henoch-Schonlein purpura
- Fever
- Rash
- Joint pain - knees and ankles, 2/3 of patients
- Colicky abdominal pain (hematemesis, melena)
- Renal involvement - 80% have micro- or macroscopic hematuria or mild proteinuria
Most common chronic glomerular disease
IgA nephropathy (Berger disease)
Most common familial nephritis
Alport syndrome
- Usually associated with nerve deafness and ocular defects
Most common vasculitis to involve the kidneys
Henoch-Schonlein purpura
Clinical presentations in hypertension
- Vomiting
- Headaches
- Facial palsy
- Hypertensive retinopathy
- Convulsions
- Proteinuria
Most common features of hypertension in infants
- Cardiac failure
- Faltering growth
Causes of hypertension
- Renal
- Renal artery stenosis
- Renal parenchymal disease
- Polycystic disease
- Renal tumors
- Coarctation of the aorta
- Catecholamine excess
- Pheochromocytoma
- Neuroblastoma
- Endocrine
- Congenital adrenal hyperplasia
- Cushing syndrome or corticosteroid therapy
- Hyperthyroidism
- Essential HTN
Causes of unilateral palpable kidney
- Multicystic kidney
- Compensatory hypertrophy
- Obstructed hydronephrosis
- Renal tumor (Wilms tumor)
- Renal vein thrombosis
Causes of bilateral palpable kidneys
- ARPKD - most common cause
- ADPKD
- Tuberous sclerosis
- Renal vein thrombosis
Fanconi syndrome causes dysfunction of which part of the kidneys?
Proximal tubules
Features of Fanconi syndrome
- Excessive loss of:
- Amino acids
- Glucose
- Phosphate
- Bicarbonate
- Sodium
- Calcium
- Potassium
- Magnesium
Clinical presentation of Fanconi syndrome
- Polydipsia and polyuria
- Salt depletion and dehydration
- Hyperchloremic metabolic acidosis
- Rickets
- Faltering or poor growth
Definition of oliguria
<0,5 ml/kg per hour
Most common cause of acute kidney injury
Prerenal - hypovolemi
- Gastroenteritis
- Burns
- Sepsis
- Hemorrhage
- Nephrotic syndrome
Features of acute-on-chronic renal failure
- Growth failure
- Anemia
- Disordered bone mineralization (renal osteodystrophy)
2 most common renal causes of acute renal failure
- Haemolytic uraemic syndrome
2. Acute tubular necrosis
Triad of hemolytic uremic syndrome (HUS)
- Acute renal failure
- Microangiopathic hemolytic anemia
- Thrombocytopenia
Cause of HUS
GI infection with verocytotoxin-producing E. coli O157:H7
Definition of stage 5 chronic kidney disease
End stage renal failure
GRF <15 ml/min per 1,73 m2
Bile-stained vomit can be caused by
Intestinal obstruction
Hematemesis can be caused by
- Esophagitis
- Peptic ulceration
- Oral/nasal bleeding
- Esophageal variceal bleeding
Projectile vomiting, in first weeks of life can indicate
Pyloric stenosis
Vomiting at the end of paroxysmal coughing can indicted
Whooping cough (pertussis)
Abdominal distention can indicate
Intestinal obstruction including strangulated inguinal hernia
Blood in stool can indicate
- Intussusception
- Bacterial gastroenteritis
Clinical features of gastro-esophageal reflux
- Recurrent regurgitation or vomiting
- Infant is putting one weight normally and are otherwise well
Gastro-esophageal reflux disease is more common in which children?
- Children with CP or other neurodevelopmental disorders
- Preterm infants, especially in those with BPD
- Following surgery for esophageal atresia or diaphragmatic hernia
Complications of G-E reflux = G-E disease
- Faltering growth from severe vomiting
- Esophagitis:
- Hematemesis
- Discomfort on feeding or heartburn
- Iron-deficiency anemia
- Recurrent pulmonary aspiration
- Recurrent pneumonia
- Cough or wheeze
- Apnea in preterm infants
- Dystonic neck posturing (Sandifer syndrome)
- Apparent life-threatening events
Investigations of G-E reflux
- 24-houre esophageal pH
- 24-houre impedance monitoring
- Endoscopy with esophageal biopsies
What is normal lower esophageal pH?
Above 4 for most of the time
Management of G-E reflux
- Thickening agents to feed
- Smaller, more frequent feeds
- Acid suppressants:
- H1-receptor antagonists (e.g. Ranitidine)
- PPIs (e.g. Omeprazole
- Surgical management - only in children with complications unresponsive to treatment
- Nissan fundoplication
Pathophys of pyloric stenosis
- Hypertrophy of the pyloric muscle - gastric outlet obstruction
When does the clinical features of pyloric stenosis present?
At 2-8 weeks of age.
More common in boys (4:1)
Clinical features of pyloric stensosis
- Vomiting, increases in frequency and forcefulness over time - becoming projectile
- Hunger after vomiting
- Dehydration
- Weight loss
Blood gass i pyloric stenosis show
Hypochloremic metabolic alkalosis with a low plasma sodium and potassium
Findings on physical examination of pyloric stenosis
- Gastric peristalsis may be seen as a wave moving from left to right across the abdomen
- Palpation of the pyloric mass - olive shaped in right upper quadrant
Management of pyloric stenosis
- Fluid and electrolyte treatment
- Pyloromyotomy - division of the hypertrophied muscle down to, not including, the mucosa.
Extra-abdominal causes of acute abdominal pain
- URT infection
- Lower lobe pneumonia
- Torsion of the testis
- Hip and spine
Surgical causes of acute abdominal pain
- Acute appendicitis
- Intestinal obstruction including intussusception
- Inguinal hernia
- Peritonitis
- Inflamed mocked diverticulum
- Pancreatitis
- Trauma
Clinical features and signs of acute uncomplicated appendicitis
Symptoms: - Anorexia - Vomiting - Abdominal pain (initially central and colicky, then localized to the right iliac fossa) Signs: - Fever - Abdominal pain aggravated by movement - Persisten tenderness with guarding
Where does intussusception most often appear?
Ileum passing into the caecum through the ileocaecal valve
- proximal bowel into a distal segment
Complications of intussusception
Stretching and constriction of the mesentery –> venous obstruction –> engorgement and bleeding from the bowel mucosa –> fluid loss –> bowel perforation, peritonitis, gut necrosis
Clinical features of intussusception
- Paroxysmal, severe colicky pain with pallor
- May refuse feeds, may vomit
- A sausage-shaped mass, palpable in the abdomen
- Characteristic redcurrant jelly stool
- Abdominal distension and shock
What can you see on a abdominal x-ray and USG in intussusception?
X-ray: * Distended small bowel * Absence of gas in the distal colon or rectum USG: * Target/doughnut sign
What does Meckel diverticulum consist of?
Is an ileal remnant of the vitelli-intetsinal duct.
- Contains ectopic gastric mucosa or pancreatic tissue
Pathphys of IBS
- Altered GI motility
- Abnormal sensation of intra-abdominal events
- Symptoms may be precipitated by a GI infection
- Abnormally forceful contractions in small intestine
Clinical features of IBS
- Non-specific abdominal pain, may be worse before or relieved by defecation
- Explosive, loose or mucous stools
- Bloating
- Feeling of incomplete defecation
- Constipation
Treatment of peptic ulcer
- PPI (e.g. Omeprazole)
- If H. pylori - Amoxicillin and Metronidazole or Clarithromycin
What is eosinophilic esophagitis?
- Inflammation of esophagus, caused by activation of eosinophils within the mucosa and submucosa
- Unknown pathophys. but probably connected with allergy (more common in atopic children)
- Dx: endoscopy
- Tx: oral corticosteroids
Most common virus causing gastroenteritis in develop countries
Rotavirus
60% of cases in children under 2 years of age
- Other viruses: adenovirus, norovirus, calicivirus, coronavirus, astrovirus
Most common bacteria causing gastroenteritis in developed countries
- C. jejuni
Features for Shigella and Salmonella
- Dysenteric type of infection
- Blood and pus in the stool
- Pain
- Tenesmus
Children at increased risk of dehydration from gastroenteritis
- Infants, <6 months of age, those born with low birthweight
- Passed six or more diarrheal stools in previous 24h
- Vomited three or more times in previous 24h
- Unable to tolerate extra fluids
- Malnutrition
Degrees of dehydration
- Not clinically detectable (<5% loss of body weight)
- Clinical dehydration (5-10% loss of body weight)
- Shock (>10% loss of body weight)
Clinical features of shock from dehydration in an infant
- Prolonged capillary refill time
- Tachycardia. Weak peripheral pulses
- Reduces tissue turgor
- Sudden weight loss
- Reduced urine output
- Cold extremities
- Tachypnea
- Eyes sunken and tearless
- Dry mucous membranes
- Sunken fontanelle
- Decreased level of consciousness
- Pale or mottled skin
- Hypotension
Clinical features of coeliac disease
- Faltering growth
- Abdominal distension
- Buttock wasting
- Abnormal stools
- General irritability
Serological tests fro coeliac disease
- Anti-tTG (immunoglobulin A tissue transglutaminase antibodies)
- EMA (endomysial antibodies)
Diagnosis of coeliac disease
- Endoscopy biopsy, mucosal changes
- Increased intraepithelial lymphocytes
- Variable degree of villous atrophy and crypt hypertrophy
Most common inflammatory bowel disease
Crohn’s disease is more common than UC
Clinical features of Crohn’s disease
- General ill health (fever, lethargy, weight loss) - often presenting symptoms
- Growth failure, puberty delayed
- Abdominal pain, diarrhea
- Extra-intestinal: oral lesions or perianal skin tags, uveitis, arthralgia, erythema nodosum
- Labs: raised inflammatory markers (platelet, ESR, CRP), iron-deficiency anemia, low serum albumin)
Pathophys of Crohn’s disease
- Can affect whole GI tract, most commonly distal ileum and proximal colon
- Transmural, focal, subacute or chronic inflammation
- Initially - areas of acutely inflamed, thickened bowel
- Fistula may develop
Histological hallmark of Crohn’s disease
Non-caseating epithelioid cell granulomata
Management for Crohn’s disease
- Nutritional therapy - normal diet replaced by whole protein modular feeds for 6-8 weeks - effective in 75%
- Systemic steroids if diet ineffective
- When relapses - immunosuppressants:
- Azathioprine
- Mercaptopurine
- Methotrexate
(Anti-tumour necrosis factor agents when conventional treatments have failed)
Complications of Crohn’s
- Obstruction
- Fistula
- Abscess
Clinical features of Ulcerative colitis
- Rectal bleeding
- Diarrhea
- Colicky pain
- Weight loss and growth failure may occur (less frequent than in Crohn’s)
- Extra-intestinal: Erythema nodosum, arthritis
Pathophys of UC
- Affects the colon
- Confluent colitis - extend from rectum proximally. 90% of children have pancolitis (all colon)
Histology of UC
- Mucosal inflammation
- Cryp damage (cryptitis, architectural distortion, abscesses and crypt loss)
- Ulceration
Management of UC
- Mild disease: Aminosalicylates (e.g., Mesalazine) (induction and maintenance therapy)
- Confined to rectum and sigmoid - topical steroids
- Aggressive or extensive: systemic steroids, immunomodulatory therapy
Primary underlying causes of constipation
- Hirschsprung disease
- Lower spinal cord problems
- Anorectal abnormalities
- Hypothyroidism
- Coeliac disease
- Hypercalcemia
Pathophys of Hirschsprung disease
Absence of ganglion cells from the myenteric and submucosal plexuses of part of the large bowel
75% of cases the lesion is confined to the rectosigmoid
Clinical features of Hirschsprung disease
- In neonatal period:
- Intestinal obstruction - failure to pass meconium within the first 24h.
- Abdominal distention
- Later bile-stained vomiting
- Later in life:
- Profound chronic constipation
- Abdominal distention
- Growth failure
Diagnosis of Hirschsprung disease
- Suction rectal biopsy:
- Absence of ganglion cells
- Presence of large, acetylcholinesterase-positive nerve trunks
