Misc Flashcards
Acute mountain sickness
generally a self-limiting condition. Features of AMS start to occur above 2,500 - 3,000m, developing gradually over 6-12 hours and potentially last a number of days:
* Headache * Nausea
* Fatigue
Prevention and treatment of AMS
The risk of AMS may actually be positively correlated to physical fitness
* Gain altitude at no more than 500 m per day
* Acetazolamide (a carbonic anhydrase inhibitor) is widely used to prevent AMS and has a
supporting evidence base
* Treatment: descent
high altitude pulmonary edema (HAPE)
Descent
* Dexamethasone, nifedipine, phosphodiesterase type V inhibitors (Sildenafil)
* Oxygen if available
Hereditary Angioedema Description of disease
autosomal dominant condition associated with low plasma levels of the C1 inhibitor (C1-INH) protein. C1-INH is a multifunctional serine protease inhibitor - the probable mechanism behind attacks is uncontrolled release of bradykinin resulting in edema of tissues
Hereditary Angioedemam investigation
- C1-INH level is low
- Low C2 and C4 levels are seen, even between attacks
Hereditary Angioedemama Symptoms
Symptoms
* Attacks may be proceeded by painful macular rash
* Painless, non-pruritic swelling of subcutaneous/submucosal tissues
* May affect upper airways, skin or abdominal organs (can occasionally present as abdominal pain due to visceral edema)
* Urticaria is not usually a feature
Hereditary Angioedemama management
Acute: IV C1-inhibitor concentrate or FFP
* Anabolic steroid; Danazol may help
Galactosemia
a rare autosomal recessive condition caused by the absence of galactose-1- phosphate uridyl transferase. This results in intracellular accumulation of galactose-1-phosphate
Features
* Jaundice
* Failure to thrive
* Hepatomegaly
* Cataracts
* Hypoglycemia after exposure to galactose
* Fanconi syndrome
Diagnosis
* Urine reducing substances
DVT Risk Factors:
Hematological
* Thrombophilia: e.g. Activated protein C resistance, protein C and S deficiency
* Polycythemia
* Paroxysmal nocturnal hemoglobinuria
* Hyperviscosity syndrome
Autoimmune
* Antiphospholipid syndrome * Behcet’s
Drugs
* Combined oral contraceptive pill: 3rd generation more than 2nd generation
* Antipsychotics (especially olanzapine) have recently been shown to be a risk factor
Other conditions
* Homocystinuria
Motion sickness
describes the nausea and vomiting which occurs when an apparent discrepancy exists between visually perceived movement and the vestibular systems sense of movement.
Management
* The BNF recommends hyoscine (e.g. Transdermal patch) as being the most effective treatment. Use is limited due to side-effects
* Non-sedating antihistamines such as cyclizine or cinnarizine are recommended in preference to sedating preparation such as promethazine
Acute intermittent porphyria (AIP) (Acute)
- Autosomal dominant
- Defect in porphobilinogen deAminase
- Results accumulation of delta aminolaevulinic acid and porphobilinogen
- ♀s, 20-40 year olds more likely to be affected (♀5:1)
- Typically present with abdominal symptoms, neuropsychiatric symptoms
- Hypertension and tachycardia common
- Urine turns deep red on standing
Acute intermittent porphyria (AIP) (Acute) Features
Abdominal: abdominal pain, vomiting
* Neurological: motor neuropathy
* Psychiatric: e.g. Depression
* Hypertension and tachycardia common
* No feces porphyria (can not be detected in
stool)
Acute intermittent porphyria (AIP) Diagnosis
Classically urine turns deep red on standing
* Raised urinary porphobilinogen (elevated between attacks and to a greater extent during acute attacks)
* Assay of red cells for porphobilinogen deaminase
* Raised serum levels of delta aminolaevulinic acid and porphobilinogen
Acute intermittent porphyria (AIP) treatment
Hematin: needs to be given very early in an attack to be effective. Effectiveness varies among individuals. They are not curative drugs, but can shorten attacks and reduce the intensity of an attack
Porphyria cutanea tarda (PCT) (Non-acute)
- Most common hepatic porphyria
- 80% sporadic and 20% autosomal dominant
- No neurological consequences only urine porphyria
- The exact frequency is not clear because many people with PCT never experience symptoms
- Defect in uroporphyrinogen decarboxylase
- May be caused by hepatocyte damage e.g. Alcohol, estrogens
- Classically photosensitive rash with bullae, skin fragility on face and dorsal aspect of hands
- Urine: elevated uroporphyrinogen and pink fluorescence of urine under wood’s lamp
- Manage with chloroquine
Variegate porphyria
Autosomal dominant
* Defect in protoporphyrinogen oxidase
* Photosensitive blistering rash
* Abdominal and neurological symptoms
* More common in south africans
Kartagener’s syndrome
(also known as primary ciliary dyskinesia) was first described in 1933 and most frequently occurs in examinations due to its association with dextrocardia (e.g. ‘quiet heart sounds’, ‘small volume complexes in lateral leads’)
Features
* Dextrocardia or complete situs inversus
* Bronchiectasis
* Recurrent sinusitis
* Subfertility (secondary to diminished sperm motility and defective ciliary action in the fallopian
tubes)
Superior Vena Caval Obstruction (SVCO)
is an uncommon manifestation of mediastinal masses, but it is particularly for small-cell lung cancer.
Treatment depends on the cause and pace of the progression of symptoms.
* Although SVCO is an emergency in the presence of airway compromise, where possible it is
important to get tissue for a histological diagnosis, as some tumours are better treated with chemotherapy than radiotherapy. In this case, if feasible, a bronchoscopy would probably provide tissue for a diagnosis.
* For most tumours, radiotherapy is a good treatment and relieves symptoms in 90% of patients within 2 weeks.
* Patients should be sat up and given oxygen to provide initial relief.
* In severe cases high-dose steroids can be helpful.
* For patients with recurrent SVCO, insertion of expandable wire stents under radiological
guidance provides relief in a high proportion of patients.
Amyloidosis: diagnosis
iagnosis:
* Biopsy of abdominal wall fat, the rectum or a salivary gland can be examined for evidence of
characteristic amyloid deposits. The tissue is treated with Congo red stain, which combined
with polarized light makes the amyloid proteins appear apple-green on microscopy.
* Abdominal wall fat biopsy is not completely sensitive, and sometimes biopsy of an involved
organ (such as the kidney) is required to achieve a diagnosis
* The nature of the amyloid protein (type) can be determined by various ways:
o Protein electrophoresis or light chain determination
o Binding of particular antibodies to the amyloid found in the tissue
o Extraction of the protein and identification of its individual amino acids
AL amyloid
o L for immunoglobulin Light chain fragment
o Due to myeloma, Waldenstrom’s, MGUS
o Features include: cardiac and neurological involvement, macroglossia, periorbital
eccymoses
- AA amyloid
A for precursor serum amyloid A protein, an acute phase reactant o Seen in chronic infection/inflammation
o E.g. TB, bronchiectasis, rheumatoid arthritis
o Features: renal involvement most common feature
- β-2 microglobulin amyloidosis
Precursor protein is β-2 microglobulin, part of the major histocompatibility complex o Associated with patients on renal dialysis
Cardiac amyloidosis
Cardiac amyloidosis most commonly presents as restrictive cardiomyopathy, associated with AL Amyloidosis
Presentation:
* Typical presentation of right heart failure: o Jugular venous distension
o Peripheral oedema
o Orthopnoea and paroxysmal nocturnal dyspnea are typically absent
POEMS Syndrome
Polyneuropathy, Organomegaly, Endocrinopathy or Edema, M-protein and Skin abnormalities
plasma-cell proliferative disorder (typically myeloma), polyneuropathy and organomegaly. Average age of onset is 50 years, ♂:♀ 2:1. Its 5 years survival is 60% if untreated
Management:
* No treatment was found, just correct the hematological abnormality
* Conventional treatments for demyelinating neuropathy (Steroids, IV immunoglobulin and
plasma exchange) are ineffective; treatment must be aimed at the hematological disorder.
