Module C Flashcards
Raised anion gap metabolic acidosis causes
- lactate: shock, hypoxia
- ketones: diabetic ketoacidosis, alcohol
- urate: renal failure
- acid poisoning: salicylates, methanol
- 5-oxoproline: chronic paracetamol use
Normal anion gap or hyperchloraemic metabolic acidosis causes
- gastrointestinal bicarbonate loss: diarrhoea, ureterosigmoidostomy, fistula, renal tubular acidosis
- drugs: e.g. acetazolamide, ammonium chloride injection
- Addison’s disease
Signs of negative or under-filled fluid balance
Tachycardia Hypotension Oliguria Sunken eyes Reduced skin turgor
Signs of positive or over-filled fluid balance
Ascites
Crackles
Tachypnoea
Elevated JVP
Most important intracellular cation and anion
Cation: K+
Anion: PO4-
Most important extracellular cation and anion
Cation: Na+
Anion: Cl-
Prescribing maintenance fluid (requirements)
25-30ml/kg/day H2O
1mmol/kg/day Na+/K+/Cl-
50-100mg/day glucose (to prevent starvation ketosis)
Plasma concentration of electrolytes
Na+ 135-145mmol/L
K+ 3.5-5mmol/L
Cl- 98-105
HCO3- 22-28mmol/L
IV fluid composition - 0.9% saline, 5% glucose, 0.18% saline with 4% glucose, Hartmann’s solution
0.9% saline = 154mmol/L Na+ & 154mmol/K Cl-
5% glucose = 50g glucose
0.18% saline with 4% glucose = 30mmol/L Na+, 30mmol/L Cl- and 40g glucose
Hartmann’s solution = 131mmol/L Na+, 111mmol/L Cl-, 5mmol/L K+, 29mmol/L HCO3-
Henoch-Schonlein purpura
HSP is an IgA mediated small vessel vasculitis
Commonly seen in children after an infection
Results in palpable purpuric buttock rash, abdo pain, polyarthritis, IgA nephropathy features (e.g. haematuria, renal failure)
Tx: analgesia for polyarthritis, supportive tx/steroids/immunosuppressants for nephropathy
Prognosis: self-limiting condition, 1/3 children relapse
IgA nephropathy
Signs: haematuria, renal failure
Commonest cause of renal disease (female vs male)
Female: UTI
Male: BPH
Dysuria
Pain on micturition
Causes: inflammation of urethra or bladder (e.g. UTI, Chlamydia trachomatis or Neisseria gonorrhoeae infections) OR inflammation of vagina or glans penis (e.g. Candida albicans or Gardnerella vaginalis infections)
Oliguria
Reduced urine output (<0.5ml/kg/hr)
Causes: AKI, urinary obstruction, or hypotensive/hypovolaemic patient
Polyuria
Excessive urine output (> 2.5-3L/day)
Causes: polydipsia, diabetes insipidus, CKD, solute diuresis (e.g. hyperglycaemia with glycosuria)
Nocturia
Night time urination
Causes: drinking before bed, prostatic enlargement
Kidney pain
Typically loin or flank pain
May radiate to iliac fossa or testes depending on cause
Anuria
No urine output
Causes: bladder outflow obstruction, or bilateral ureteric obstruction
Microalbuminuria
Increased albumin excretion in urine undetected by dipstick (30-300mg/day)
Early indicator of renal disease
Pyuria
Pus in urine
Seen in partially treated UTI, urinary tract tuberculosis, calculi, bladder tumour, papillary necrosis and tubulointerstitial nephritis
Pathognomonic finding of glomerulonephritis
Red cell casts on urine microscopy
White cell casts on urine microscopy
Seen in acute pyelonephritis, interstitial nephritis, and glomerulonephritis
Granular casts on urine microscopy
Indicate glomerular or tubular disease due to degenerated tubular cells - seen with CKD
Urolithiasis
Ureteric obstruction