First Aid Pathology Pt 1 Flashcards
What causes rhinosinusitis and what does it cause?
Obstruction of the sinus drainage into the nasal cavity which causes inflammation and pain
Which sinus is typically affected in rhinosinusitis?
The maxillary sinuses which drain against gravity as the Ostia is located superomedially
What does the superior, middle and inferior meatus of the nasal cavity drain?
Superior: sphenoid, posterior ethmoid
Middle: frontal, maxillary and anterior ethmoid
Inferior: nasolacrimal duct
What is the most common acute cause of rhinosinusitis?
Viral URI which can lead to a superimposed bacterial infection (most commonly H. influenza, S. pneumonia, M. catarrhalis)
Where might paranasal sinus infections extend to and what can happen as a result?
Orbits, cavernous sinus, and brain
May cause: orbital cellulitis, cavernous sinus syndrome, meningitis
What is epistaxis and where does it most commonly occur? Name four common causes
Nose bleeds, most commonly occur in the anterior segment of nasal cavity. Common causes include trauma, foreign body, allergic rhinitis and nasal angiofibroma
Where do life-threatening hemorrhages (epistaxis) commonly occur and why?
The posterior segment of the nasal cavity as this is where the sphenopalatine artery is (a major branch of the maxillary artery)
What is a nasal angiofibroma and what group of people are more commonly affected by it?
Benign but locally aggressive vascular tumour of the nasopharynx (grows in the back of the nasal cavity), most commonly affects adolescent males
What are the arteries supplying the Kiesselbach plexus of the nasal septum?
Kiesselbach drives his LEXUS with his LEGS
- Labial artery
- Posterior and anterior ethmoidal artery
- Greater palatine artery
- Sphenopalatine artery
What is the most common kind of head and neck cancer? Name four risk factors
SCC is the most common
RFs: tobacco, alcohol, EBV (nasopharyngeal), HPV-16 (oropharyngeal)
What is field cancerization? How does it affect the head and neck and parts of the body in general?
When a carcinogen damages a large area of the mucosal surface, this causes multiple tumours to arise independently after one exposure
What predisposes you to a DVT?
SHE
S: Stasis
H: Hypercoagulability (clotting protein defect (like factor 5 Leiden), OCP, pregnancy)
E: Endothelial damage, as collagen exposure triggers the clotting cascade
How does pregnancy increase the risk of a DVT?
Increase in clotting proteins (due to placenta), and the uterus can place increased pressure on the veins causing stasis
Where do most pulmonary emboli arise from?
The proximal deep veins of the lower extremity
What is the D-dimer lab test used for clinically? What does a high D-dimer
Used to rule out a DVT in low-moderate risk patients (as it has a high sensitivity but low specificity)
A high d-dimer indicates high levels of fibrin degradation products and lots of thrombus formation and breakdown – but won’t tell you location or cause
How is a DVT managed…
a) for prophylaxis and acute management
b) for treatment and long-term prevention
a) Unfractionated or low molecular weight heparin (like enoxaparin)
b) oral anticoagulants like warfarin
What is the imaging test of choice for a DVT?
Compression ultrasound with doppler
What is the imaging test of choice for a PE and why?
What abnormality might be present on an ECG?
CT pulmonary angiography as it can visualize filling defects, which are thrombi in situ caused by stasis (not PEs)
ECG: SQI3T3
What can happen as a result of large emboli or saddle embolus in the lungs?
Sudden death due to electromechanical dissociation (pulseless electrical activity)
How can a PE induce respiratory alkalosis?
Causes a V/Q mismatch which induces hypoxia and hyperventilation
Name four ‘sudden-onset’ symptoms that might occur in a patient with a PE
Dyspnea, pleuritic chest pain, tachypnea and tachycardia
What forms the lines of Zahn and what do they indicate?
Lines of Zahn are interdigitating areas pf pink (platelet and fibrin) and red (RBCs) found in thrombi ONLY before death, and thus can help distinguish pre and postmortem thrombi
What are the six types of emboli?
FAT BAT
F: fat A: air T: thrombi B: bacteria A: amniotic fluid T: Tumour
What is associated with a fat embolus and how does it usually present
Fracture at the end of long bones and liposuction: presents with the classic triad of neurological abnormalities, hypoxemia and petechial rashes (little red spots on the skin as a result of excessive bleeding)
What can cause an air embolus and how is it treated
- Nitrogen precipitating in the blood (of ascending divers), can be treated with hyperbaric O2
- Iatrogenic (i.e after a central line placement).
What three vessels are most commonly used for central line placements?
Femoral vein, subclavian vein, internal jugular vein
When and why do amniotic fluid emboli tend to occur? What can they lead to and how common are they?
Tend to occur during labour or postpartum, but can be due to uterine trauma. Can lead to a DIC (disseminated intravascular coagulation; blood clots forming throughout the body which can occlude the small vessels)
Rare but high mortality
What structures are contained in the normal mediastinum?
HEAT L: Heart, esophagus, aorta, thymus, lymph nodes
What pathologies commonly occur in the anterior, middle and posterior mediastinum?
Anterior: 4Ts; thymic neoplasm, thyroid (substernal goitre), teratoma, “terrible” lymphoma
Middle: esophageal carcinoma, metastasis, hiatal hernia, bronchogenic cysts
Inferior: neurogenic tumours (ie neurofibroma), multiple myeloma
What is mediastinitis and why commonly causes it?
Inflammation of the mediastinal tissue, commonly due to…
- postoperative complications of cardiothoracic procedures (will present in <14 days)
- Esophageal perforation
- The continuous spread of odontogenic/retropharyngeal infections
How does mediastinitis commonly present?
FTLCS: Fever, temperature, leukocytosis, chest pain and sternal wound drainage
What is a pneumomediastinum and how can it be caused?
Presence of air (typically gas) in the mediastinum. Can be caused
1. Spontaneously: Rupture of a pulmonary bleb (small air bubble between the lung and visceral pleura)
- Caused by trauma, iatrogenic, Boerhaave syndrome
What causes Boerhaave syndrome (including the causative symptoms)
Esophageal rupture due to increased intraesophageal pressure and negative intrathoracic pressure, can occur with vomiting and severe straining
What happens as a result of ruptured alveoli in a pneumomediastinum
Air goes into the mediastinum via the peribronchial and perivascular sheaths
What are the clinical features of pneumomediastinum?
CDVSH: chest pain, dyspnea, voice change, subcutaneous emphysema, (+) Hammond’s sign (crackles on cardiac auscultation)
