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
Transcutaneous renal biopsy
Ultrasound guided
Used for nephritic and nephrotic syndromes, AKI and CKD, haematuria after negative urological investigations and renal graft dysfunction
Complications: haematuria, flank pain and perirenal haematoma formation
Glomerulonephritis
Typically an immunologically-mediated injury of the glomeruli involving both kidneys, and may be part of a systemic disease (e.g. SLE)
Plural: glomerulonephridities
Proliferative glomerular histology
Increase in cell numbers in glomerulus due to hyperplasia of at least one resident glomerular cell with/out inflammation
Crescents in glomerular histology
Epithelial cell proliferation in Bowman’s space, signifies severe glomerular injury as there is mononuclear cell infiltration in Bowman’s capsule
Serum anti-streptolysin-O titre
Used with culture to confirm recent Streptococcal infection
Membrane alterations in glomerular histology
Capillary wall thickening due to deposition of immune deposits or alterations in basement membrane
Overview of kidney
Retroperitoneal structure located on either side of vertebral column at level of T12-L3
Renal capsule and ureters innervated by T10-L1
Receive 25% of cardiac output
Functions:
- excretion of waste and drugs
- catabolism of hormones e.g. insulin
- regulation of volume and composition of body fluid
- regulation of acid-base balance
- production of erythropoietin and renin
- metabolism of VitD to active form
- production of endothelin, prostaglandins, renal natriuretic peptide
Prostadynia
Prostatic pain without an infection
May be seen in men recovering from bacterial prostatitis
What conditions are classified as UTIs?
Prostatitis Cystitis Epididymitis Acute pyelonephritis Balanitis Urethritis
Crystals seen in urine microscopy
Uric acid due to uric acid stones, or tumour lysis syndrome
Calcium oxalate due to stones, high oxalate diet, ethylene glycol poisoning
Cystine seen in cystinuria (autosomal recessive defect)
Anterior triangle boundaries
Superior: inferior border of mandible
Medial: midline of neck
Lateral: anterior border of sternocleidomastoid
Posterior triangle boundaries
Anterior: posterior margin of sternocleidomastoid muscle
Posterior: anterior margin of trapezius muscle
Inferior: middle 1/3 of clavicle
Haemopoeisis
Formation of blood cells
RBCs 120d
Platelets 7d
Granulocytes 7hrs
Plasma vs Serum
Plasma = fluid component of blood with soluble fibrinogen present Serum = remaining fluid after fibrin clot has formed
Haematocrit
Proportion of total blood volume occupied by erythrocytes
AKA packed cell volume
Percentage or ratio obtained by centrifuging blood sample and measuring height of RBCs compared to height of blood sample
Pluripotent stem cells
Able to differentiate into any type of blood cells
Abundant in bone marrow of pelvis, ribs, sternum, vertebrae, clavicles, scapulae, and skull
Drug causes of thrombocytopenia
Heparin (UH > LMWH) Alcohol Quinine/quinidine Sulfa drugs Etc.
Which antibiotic classes cause inhibition of bacterial cell wall synthesis?
Monobactams Carbapenems Penicillins Cephalosporins Glycopeptides
Which antibiotic classes cause inhibition of bacterial protein synthesis?
Aminoglycosides
Macrolides
Tetracyclines
Chloramphenicol
Inhibition of bacterial DNA synthesis
Rifampicin
Quinolones
Which antibiotic classes cause inhibition of bacterial folic acid metabolism?
Trimethoprim
Sulphonamides
Toxoplasmosis
Caused by Toxoplasma gondii = protozoa parasite
Infects via GI tract, broken skin, lung
Oocytes release trophozoites which migrate to eye, brain and muscle
Animal reservoir = cat, rat
Self limiting infection in immunocompetent pts with mononucleosis symptoms seen e.g. fever, lymphadenopathy, malaise
Immunocompromised pts e.g. HIV may present with cerebral toxoplasmosis causing constitutional symptoms, headache, confusion and drowsiness
Toxoplasmosis can mimic EBV in immunocompromised pt
Investigations show: raised platelet count, raised CRP, normal Hb, normal WBC, negative EBV
CT may show single or multiple ring, possible mass effect
Treatment: pyrimethamine & sulphadiazine for 6 weeks
Migraine
Px: throbbing painful headache, N&V, photophobia
Associated with GI upset in children
Tx: 50-100mg PO sumatriptan for acute tx with analgesia, consider anti-emetic (metoclopramide)
Preventative tx: 80-160mg PO propanolol, 50-100mg PO topiramate, 25-75mg amitriptyline
Myasthenia gravis
Autoimmune disorder with antibodies against acetylcholine receptors (85-90%); F>M
Px: extraocular muscle weakness (diplopia), proximal muscle weakness (face, neck, limb girdle), ptosis (drooping eyelid), dysphagia
Associated with thymomas (30-40% of pts), thymic hyperplasia, SLE, RA, autoimmune thyroid disorders, pernicious anaemia
Ix: single fibre electromyography, antibody, CT thorax, CK normal
Tx: pyridostigmine (long-acting acetylcholinesterase), immunosuppression with prednisolone initially (may also use azathioprine, cyclosporine, mycophenolate mofetil)
Note: if acetylcholine antibodies absent, anti-muscle-specific tyrosine kinase antibodies may be present in 40%
Lambert-Eaton myasthenic syndrome
Autoantibodies directed against presynaptic VGCCat NMJ in the PNS
Gradual onset proximal muscle weakness in legs/arms, hyporeflexia, autonomic sx (constipation, dry mouth, difficulty urinating, impotence)
Associated with small cell lung cancer, and less commonly breast/ovarian cancer
Lambert’s sign: increased response to repetitive stimulation resulting in improving grip strength during electromyography
Tx: cancer mx, prednisolone, azathioprine, IVIG or plasma exchange
Different from MG due to no ocular involvement, and increasing grip strength (MG causes reduced strength)
Muscular dystrophy
Associated with cardiac abnormalities and diabetes
Buerger’s disease
Typical presentation: combination of Raynaud’s syndrome, intermittent claudication and finger ulcerations in a young smoker
Small and medium vessel vasculitis
Features
extremity ischaemia = intermittent claudication and ischaemic ulcers
superficial thrombophlebitis
Raynaud’s phenomenon
Acid-fast bacillus smear
Positive for all mycobacterium species
Monospot test
Specific for infectious mononucleosis (Glandular fever) due to EBV
Mantoux test
Used for latent TB
Potassium infusion rate via peripheral line
10mmol/L per hour of potassium hence 40mmol/L in 4hrs
If given too fast, can cause cardiac arrhythmias
Infusion rate for 0.9% sodium chloride
1L over 6 hours
RBC transfusion in ACS patient
Start if Hb < 80g/L
Target: 80-100g/L
RBC transfusion in pt without ACS
Start if Hb < 70g/L
Target: 70-90g/L
Threshold disregarded if pt is experiencing major haemorrhagic bleeding
RBC transfusion rate (non-emergency)
90-120mins for 1 unit
Syphilis
Painless genital ulcer (chancre) seen in pt with unprotected sex with frequent partners
May also see constitutional symptoms and inguinal lymph node enlargement
Caused by Treponema pallidum bacteria (gram negative spirochaete)
Treatment: benzylpenicillin IM (or doxycycline)
First dose may cause Jarisch-Herxheimer reaction (fever, tachycardia, rash) but no treatment required other than antipyretic
Herpes simplex virus 2
Multiple painful genital ulcers seen with dysuria, and pruritus
Systemic features such as headache, fever and malaise seen with 1st episode, as well as tender inguinal lymphadenopathy, and urinary retention
Ix: nucleic acid amplification tests (NAAT = 1st line) or HSV serology
Treatment:
1st line: saline bathing, analgesia, topical anaesthetic
Consider oral aciclovir with frequent exacerbations
Elective Caesarean section if primary HSV attack after 28 weeks
Cholera
Caused by Vibrio cholerae (gram negative rod)
Symptoms: profuse (rice water) diarrhoea, dehydration, hypoglycaemia
May also see hypokalaemia and metabolic acidosis
Associated with travel to South America, Africa, Asia, and Middle East; and shellfish
Treatment: oral rehydration solution, doxycycline, ciprofloxacin
Norovirus
Non-encapsulated RNA virus, replicates in small intestine
Most common cause of gastroenteritis in UK
Symptoms include (within 15-50hrs): N&V, diarrhoea, low-grade fever, headache, myalgia
Faecal-oral transmission with spread prevented by regular handwashing; must stay off work for 48hrs
Asymptomatic bacteruria in pregnant women
Urine culture at 1st antenatal visit
Treat with 7d amoxicillin/nitrofurantoin/cefalexin to prevent pyelonephritis in mother, and premature delivery
Avoid nitrofurantoin near term
Urine culture after course of abx to ensure bacteria are cleared
UTI treatment in non-pregnant women and men
Women: Trimethoprim or nitrofurantoin 3d
Men: 7d course of trimethoprim or nitrofurantoin (unless prostatitis)
Urine culture required in >65 or haematuria (visible or non-visible)
Symptomatic UTI in pregnant women
Urine culture required
1st line tx: Nitrofurantoin (unless close to term)
2nd line tx: amoxicillin or cefalexin
UTI treatment in catheterised pt
If asymptomatic bacteruria, do not treat
If symptomatic, 7d course of trimethoprim or nitrofurantoin
Acute pyelonephritis
10-14d broad spectrum cephalosporin (or quinolone if not pregnant)
Necrotising fasciitis
Bacterial infection of deep dermis and subcutaneous tissue
Tx: Ciprofloxacin IV 400mg BD + Clindamycin 600mg IV QDS (+ benzylpenicillin 1.2g IV 4 hourly if no penicillin allergy)
Erysipelas
Superficial dermis infection
Impetigo
Ulceration of superficial skin
Seen in children typically
Golden crust - due to S. aureus
Cellulitis
Deep dermis infection (and subcutaneous tissue)
EEG
Electroencephalogram
Used to assess electrical activity of brain
Used in epilepsy to determine type and cause
May be used to investigate dementia, head injuries, tumours, encephalitis, sleep disorders
Fournier’s gangrene
NF in groin, perianal, perineal area
Ludwig’s angina
Necrotising fasciitis in submandibular space
Video telemetry
EEG with video
Dysarthria
Difficulty speaking due to damage to muscles of speech
Diplopia
Double vision
Hyperacusis
Noise sensitivity - sounds heard louder than normal