Seminar 3 - IVDU and Complications Flashcards
Describe the histological features of aspiration pneumonia
Desquaminated epithelial cells
Gastric contents
Clumps of bacteria
Alveolar haemorrhage
How do you manage mitral stenosis
Only requires management in severe cases
Can do a percutaneous balloon valvotomy, open valve commissurotomy or valve replacement
Describe the epidemiology of infective endocarditis
Incidence has been increasing
Approx. 12.7 cases per 100000
Proportion due to intracardiac devices rising but cases due to HIV fell
Describe the structure of the AV valves
Valve leaflets attach at the annulus which is a a collagenous, crown-shaped structure that is part of the fibrous skeleton of the heart
The valve has 4 layers of varying compositions of elastic and collagenous tissue – atrialis, lamina spongiosa, lamina fibrosa, ventricularis
The chordae tendinae are branching structures made up of collagen and elastic fibres
Which valve does most endocarditis develop on
Mitral valve
How can drug metabolites affect interpretation of toxicology results
Some drugs produce the exact same metabolites when broken down
e.g. opioids
Patient taking codeine will have both codeine and morphine in urine, must look at levels and determine if they also took morphine
What are the 2 types of valve disease
Stenosis - failure of valve to fully open
Insufficiency/regurgitation - failure of valve to fully close
How does aortic stenosis present
May not have symptoms until disease is severe and prognosis poor
May have signs of CHF, angina and syncope
Describe the effect of M6G
It is pharmacologically active
2x more potent than normal morphine when administered systemically
Describe the risk of contracting HIV at autopsy
Occupational exposure has been documented but is rare and there is no evidence that it is easily acquired at autopsy.
Staff at risk if they receive a cut or needlestick injury when working on an infected corpse
Estimated HIV transmission rate after a single needlestick injury is 0.1-0.36%.
Risk is increased by AIDS, high viral load or a deep injury with visible blood.
IVDU are higher risk.
How can a moving injury occur during autopsy
Incorrect moving and lifting of the body can lead to serious back injury
What is secondary haemostasis
Second stage of haemostasis
Involves the activation of the clotting cascade and the deposition of fibrin
What causes deep vein thrombosis
Trauma Surgery Contraceptive pill Tumours Pregnancy Prolonged travel/immobility Hypercoagulability or stasis usually
Describe how blood is taken for toxicology at autopsy
At least 10ml of peripheral blood taken Ideally from femoral or iliac vessels Identify location in report Sodium fluoride/potassium oxalate should be used as a preservative unless suspect poisoning with fluoride or a fluoride-producing compound exists Always taken
List the pathological features of the skin due to injection of drugs
Track marks with puckered scarring, hyper pigmentation and chronic sinuses
Skin popping scars
At time of injection you have acute bleeding and then progresses to inflammatory reaction after a few hours
Hemosiderin forms at the injection site 2-3 days post injection (shows an older site)
May have granulomatous inflammation present if foreign material also injected
Rarely some people get hypersensitivity uticarial rash post injection
What is the major metabolic pathway for morphine in the body
Conjugation with glucuronic acid (glucuronidation)
Becomes morphine-6-glucuronide (M6G) and M3G
Which valves are most susceptible to non-infectious endocarditis
Affects mitral valve > aortic valve > tricuspid valve > pulmonary valve
What is Libman-sacks endocarditis
Small sterile lesions in the heart in the context of SLE
How does morphine affect the respiratory centers in the brain
Directly affects nucleus accumbens in brainstem
Decreases responsiveness to arterial CO2
Depresses the centers responsible for regulating the rhythm of breathing
What causes superficial vein thrombosis
Varicose veins
6MAM is only detectable once the heroin has been metabolised - true or false
True (mostly)
Some forms of heroin such as black tar may contain some 6MAM but most types only produce it on metabolisation
Give examples of sharps based hazards from the body and explain how you reduce the risk
Scrape injury from the ends of cut bone - cover ends with surgical towel to prevent injury
Needle , bullet or other fragments may be found within the body
High risk corpses may get radiography prior to autopsy
Special equipment and resistant gloves used to remove
Define ‘risk’
The chance of a negative event occurring.
e.g. chance of contracting HIV from a sharp injury
List the microscopic features of subacute endocarditis
Granulation tissue at the base - sign of healing
Fibrosis -> calcification -> development of a chronic inflammatory infiltrate
Describe the risk of contracting Hep B or C at autopsy
Staff at risk if they receive a cut or needlestick injury when working on an infected corpse.
HBV is highly infectious, and transmission can occur following exposure to extremely small volumes of infected blood
HCV is less infectious but still has a transmission rate of 2.7-10% following exposure
IVDUs are at higher risk
In which body fluids can 6MAM be detected and how long for
Oral fluid - for several hours after heroin use
Urine - 12 hour detection window
May be found in vitreous humor and CSF
How can lines of Zahn be used to differentiate between between ante-mortem and postmortem thrombi
Lines of Zahn are only seen when a thrombi is formed in flowing blood
Therefore tell you it was ante-mortem
List the invasive procedures which can lead to endocarditis
Pacemaker insertion Endoscopy Colonoscopy Barium enema Dental extractions Transurethral resection of the prostate Transesophageal echocardiography Lines
Describe the effects of infection induced valvular damage
Leads to valvular insufficiency and a backflow of blood
The heart cannot pump effectively and the tissues don’t get enough O2
Leads to fatigue, muscles tiring quickly, SOB and kidney malfunction
In forensic cases, is a blood sample enough for toxicology
No
Collection of blood should be supplemented with collections of vitreous, urine, bile, gastric contents, and in some instances, CSF.
What causes pulmonary insufficiency
Pulmonary HTN, L-sided heart pathologies Endocarditis Connective tissue abnormalities Commonly occurs following surgical repair of heart eg in Tetralogy of Fallot
What are the infectious disease hazard groups
Organised by the likelihood of acquisition, severity of resulting disease, availability and efficacy of treatment and risk of transmission from staff to general public.
Group 1 - unlikely to cause human disease.
Group 2 - can cause disease and may affect employees, unlikely to spread to community and treatment available.
Group 3 - cause severe human disease and may be serious hazard to employees, may spread to community but effective treatment available.
Group 4 - cause severe human disease and may be serious hazard to employees, likely to spread to community and effective treatment not available.
List the general pathological lung changes that are caused by drug misuse
Agonal or PM movement can lead to gastric content in the lung without the inflammation
Injecting talc/lactose/crushed tablets can cause intravascular granulomatous disease
May develop septic emboli in lungs following infective endocarditis
IVDU of any drug can cause TB, pulmonary talk granulomas, foreign body emboli and pulmonary necrotising angitis
HIV can increase risk of bacterial or pneumocytic pneumonia
Which thrombi are called white thrombi
Arterial thrombi
Made up of lots of platelets and few red cells
What are the semilunar valves
The aortic and pulmonary valves
They close in diastole and open for systole
What causes pulmonary stenosis
Mostly congenital
May occur in carcinoid heart disease
Describe the microscopic features of venous thrombosis
Lots of red cells with few platelets
Lines of Zahn present - alternating layers of red cells and layers of platelets and fibrin
How do you manage tricuspid stenosis
f mild or moderate, fluid restriction, diuretics
Valve replacement, balloon dilation if severe
Which valve disease is the result of of abnormalities of the valve leaflets or aortic root dilation
Aortic regurgitation
What causes aortic stenosis
Calcification of the valve leaflets
How does aortic stenosis progress to heart failure
Valve opening becomes narrower due to calcification
This increases pressure in the left ventricle and leads to hypertrophy with ischaemia
The heart decompensates and you get congestive heart failure
Describe the risk of contracting TB at autopsy
Can get pulmonary or cutaneous infection
Incidence in post-mortem staff is greater than clinical staff.
May actually be a higher risk at autopsy than during life.
Bacilli have been found on surfaces up to 24hrs after autopsy
Intravenous drug users are at higher risk
If ante-mortem blood samples are used in toxicology, what should be considered
The gels used in many serum gel tubes may absorb drugs and affect the blood concentration
Can a person take heroin and still have a negative 6MAM test
Yes
It has a short half life so may only show up if taken recently
After 6MAM has been metabolised the person will only be positive for morphine
What can increase the window of 6MAM detection
Chronic heroin use
List the pathological features of the skin associated with crack cocaine use
Burns due to preparation
Self inflicted excoriations due to psychological delusions - often parasitic
List external signs of drug use seen on the face
Jaundice = liver failure
Necrosis of nasal tip = infective endocarditis
What are the main causative organisms of healthcare-associated or nosocomial infective endocarditis
Related to the underlying bacteremia
Typically gram-positive cocci i.e. S aureus, CoNS, enterococci, non-enterococcal streptococci
When is pre-autopsy testing carried out
If there is suspicion of a HG3 infection (or higher)
Can test for HIV if they had a high risk lifestyle without prior consent from deceased
Pulmonary manifestations of infective endocarditis are common in which patient
Those with tricuspid infections
1/3 have pleuritic chest pain
3/4 have radiograph changes
List the standard PPE for autopsy
Scrub suits, gowns, waterproof sleeves, plastic disposable aprons, caps, N95 particulate masks, eye protection (goggles or face shields), shoe covers or footwear restricted to contaminated areas, and double sets of gloves
Remove rings to prevent gloves punctures
Cut resistant gloves should be available for high risk procedures
What are the pros and cons of bioprosthetic valves
Pros – Do not require anticoagulation, can be inserted via transcatheter procedures
Cons – May only last 10-15 years so further replacement surgery may be required
Which antibiotics are used to treat prosthetic valve endocarditis
Penicillin-sensitive S viridans: penicillin G/ceftriaxone + gentamicin
Vancomycin & gentamicin
MSSA = nafcillin
What are the clinical features of endocarditis
Rapid onset of fever - most consistent symptom
Chills
Weakness and fatigue
Flu-like syndrome
Weight loss
If IE is left sided they probably have a murmur
During autopsy, whos health and safety needs to be considered
The lead pathologist
Any other staff helping in the autopsy room
Visitors such as clinical staff or medical students
Those involved in the handling of the body (relatives, funeral home staff etc.)
Laboratory workers handling the samples
Which antibiotics are used to treat native valve endocarditis
Penicillin G & gentamicin
Vancomycin if MRSA
What is the risk from ICDs on autopsy and explain how you reduce it
Risk of electric shock. To reduce, it should be inactivated before autopsy and high quality gloves used on handling.
Must be removed prior to cremation = explosion
How does heroin affect the heart
Injection of heroin can lead to infective endocarditis – does effect both left and right heart (R more common)
Will see inflammatory cells in myocardium but not fibrosis
May have myocarditis and cardiomyopathy due to HIV infection from needle sharing
Which patients are at risk from fungal endocarditis
IV drug users
ICU patients who have received broad spectrum antibiotics
Where are fibroblast samples typically taken from
Skin, fascia, lung, diaphragm and muscle
How does ecstasy affect the liver
2 forms of liver damage
Type 1 - steatosis, sinusoidal dilatation and hepatonecrosis
Causes death through hyperpyrexia
Type 2 - hepatitis and fulminant liver failure
May be due to direct toxic effect
Describe endocarditis in the context of SLE
Significant valvulitis with vegetations formed from fibrin and immune complexes
Mostly asymptomatic but may cause valvular dysfunction in severe cases
How can general drug use affect the kidneys
IV drug use causing suppurative skin infections may cause renal amyloidosis
HIV can cause FSGS
Prosthetic valves in which position are most susceptible to infective endocarditis
Mitral position are more susceptible than the aortic areas
Give examples of aerosol based hazards from the body and explain how you reduce the risk
Examples: bone dust, smoke from searing tissue for sample.
Risk of inhalation
Aerosol generating procedure limited if possible
Can use masks, filters or vacuums
How does morphine affect the respiratory centers in the brain
Directly affects it
Decreases responsiveness to arterial CO2
Depresses the centers responsible for regulatiing the rhythm of breathing
List the key vaccines suggested for autopsy workers
Hep B, TB, tetanus, polio, diphtheria, MMR
All staff should be up to date
How do you diagnose fungal IE
Microscopic examination of large emboli
What is the main difference between pharmaceutical and street heroin
Pharmaceutical heroin is made from pure morphine
Street heroin is made from morphine purified from opium extract and is extract ten contaminated with other alkaloids, e.g. codeine, noscapine
How does mitral stenosis present
Patients may present with symptoms of R-sided heart failure +/- atrial fibrillation, but even severe cases may be asymptomatic
What are the main types of embolism
Pulmonary
Fat - caused by soft tissue injuries, bone breaks or burns
Air - scuba divers rising to fast or air entering circulation
Systemic - most from cardiac mural thrombi
Amniotic - can reach mother’s lungs
Septic - particles from infection reach bloodstream and block
Retinal - small clots can block tiny vessels in the eye
Describe how injection sites are sampled for toxicology at autopsy
Resect a wide skin ellipse of needle puncture mark & surrounding skin (down to subcutaneous tissue).
Take a similar sample at a distant or contralateral site as a control. If specimen is for histology, add neutral buffered formalin
How do valve leaflets become calcified
Repeated injury to valve encourages calcium deposition
This eventually limits the movement of the valves and they stop opening fully - stenosis
Define early prosthetic valve endocarditis
Occurring within 60 days of the valve implantation
What is thrombosis
When a blood clot blocks the circulation
Disruption of normal haemostasis
List the features of ‘crack’ lung
Alveolar haemorrhage Hemosiderin laden macrophages Pneumonitis Interstitial fibrosis Carbon laden macrophages ( see right) Small artery medial hypertrophy
Additionally you’ll get barotrauma and emphysematous lung disease
Describe the extrinsic pathway of the coagulation cascade
In the presence of tissue factor, factor 7 becomes activated
This then activates factor 10
Factor 10, in the presence of Factor 5 and calcium then generates a molecule called prothrombin activator
This converts prothrombin to thrombin
Thrombin then converts fibrinogen to fibrin
How would you take a foetal tissue sample
Chorionic villus sampling has best chance of growing cell culture
Must be done as soon as intrauterine death confirmed
Fibroblasts can also be used but 1/4 will fail
How do DVTs present
May be asymptomatic
Also have localised pain, heat, oedema
At what point in the autopsy should toxicology samples be taken
Before any disruption of the body has occurred
How does rheumatic fever progress to heart failure
Acute RF leads to fusion of the leaflet commissures and thickened leaflets
This reduces flow which increases pressure in the L atrium and decreases it in the L ventricle
This leads to reduced CO and pulmonary hypertension
Results in RHF
What are the typical causative agents of subacute native valve endocarditis
Alpha-haemolytic strep or enterococci
How do you reduce transmission of transmissible spongiform encephalopathies at autopsy
Should be carried out in a separate/isolated room with limited staff if possible.
To reduce risk use waterproof gown, HEPA filters, disposable equipment where possible, keep reusable equipment wet and have a dedicated set for TSEs.
Care must be taken when removing the brain and fixing it.
Samples must be marked
Certain detergents need to be used as they denature the prions
What is the issue with existing toxicology results ‘ranges/scales’
They were created before redistribution was discovered so this is not taken into consideration
What oesophageal changes may be seen in drug misuse
Mallory Weiss tears if drug use causes a lot of vomiting
Varices may be present if liver disease
What is the most common way to take crack cocaine
To smoke it
What are the effects of carcinoid heart disease
Typically causes R sided pathology (tricuspid insufficiency, pulmonary stenosis) as this side receives blood from the liver first
How is heroin synthesised
In the presence of acetic anhydride, morphine is initially acetylated at position 3 producing 3-acetylmorphine
There is a further acetylation reaction at position 6 to give 3,6-diacetylmorphine which is heroin
Which type of vegetations are associated with more valvular destruction
Those from subacute endocarditis rather than acute endocarditis
What are the acute causes of mitral regurgitation
Infective endocarditis
Ischaemic damage to the papillary muscles
Rupture
Acute rheumatic fever
What is the half life of 6-MAM
0.6 hours
Very quickly metabolised into morphine or excreted from the body
Describe the macroscopic features of venous thrombosis
Thrombi extend in direction of blood flow
Long clot in the shape of the lumen (like a cast)
List some of the complications of infective endocarditis
Glomerulonephritis - due to antigen-antibody complex deposition
Particularly ill patients may develop sepsis, arrhythmias or emboli
Now uncommon ones include :
microthrombi (splinter or subungual haemorrhage)
Janeway lesions and osler nodes
Roth spots - retinal haemorrhages
Untreated IE can be fatal
Describe how gastric content are taken for toxicology at autopsy
Stomach tied off (reduce contamination) and emptied
The total volume is recorded
Only a few labs routinely analyse
Look for undigested pills etc.
How do opiates affect the lungs
Classically causes mushroom plume in overdose
Histologically non specific with amorphous eosinophilic material in alveolar spaces
May have aspiration pneumonitis/pneumonia – suggest opiate overdose over stimulant overdose
List the cure rates for specific IE organisms
S. viridans: 98%
Enterococci & S. aureus: 60-90%
Gram-negative bacilli/fungi: 50%
What is the purpose of vasoconstriction in haemostasis
It is an immediate response to try and stop haemorrhage
Rarely effective alone and requires the other processes
Explain how a pacemaker ‘settles into’ the heart
When implanted a fibrin/platelet thrombus can form on the generator box and leads - this is a sterile vegetation
After around a week connective tissue proliferates which partially embedding the leads in the wall of vein & endocardium
This process may offer partial protection against infection during a bacteremia
Which valve disease is the result of abnormalities to the functional unit of the valve
Mitral regurgitation
How can you reduce transmission of TB at autopsy
Autopsy should be carried out in a separate/isolated room with limited staff
Aerosol generating procedures are high risk so N95 masks or suits with HEPA filters should be worn and bulb syringe used for body fluids rather than hose aspirator.
Staff can get yearly TB tests and should be vaccinated.
Name the leaflets of the aortic valve
Left coronary, right coronary, non-coronary leaflets
What is primary haemostasis
First stage of haemostasis
Involves arteriolar vasoconstriction and formation of the platelet plug
What are the 3 active metabolites of heroin
6-MAM
Morphine
3-MAM - much less active than 6
Which patients are most prone to recurrent IE
Those who abuse IV drugs
Or those with pretreatment symptoms of IE of more than 3 months’ duration
Which patients are most likely to develop healthcare-associated or nosocomial infective endocarditis
Those with significant comorbidities More advanced age Predominant infection with S aureus High mortality May be associated with new intravascular devices
What are the general indications for surgery in endocarditis
Paraventricular abscess & intracardiac fistula
Treatment of metastatic infections
Patients with multi-resistant organisms
Persistent hypermobile vegetations - history of emboli
Which patients are susceptible to non-infective endocarditis
Those in hypercoagulable states (malignancy, sepsis)
Or those with endocardial trauma
What can contaminate blood from the general body cavity
Highly likely to be grossly contaminated by intestinal contents, effusions, urine, faeces etc.
Blood should not be taken from here.
List external signs of drug use seen on the hands
Palmar erythema and Dupuytren’s contractures = liver disease
Splinter haemorrhages = infective endocarditis
Clubbing
How does a pacemaker lead to endocarditis
A bacteremia cab infect the sterile fibrin/platelet clots or vegetations on the pacemaker
Microorganisms establish themselves on the surface of the vegetation
The process of platelet aggregation & fibrin deposition accelerate at the site
The bacteria multiply
and are covered by ever-thickening layers of platelets and thrombin
This protect them from neutrophils & other host defenses
What thrombi are called ‘red thrombi’
Venous thrombi
lots of red cells
Which antibiotics are used to treat IVDU endocarditis
Should be aimed at s.aureus
Vancomycin or amox/nafcillin
What are some of the complications of left sided IVDU endocarditis
Can be associated with systemic manifestations from embolic events
Must be special attention to renal, splenic and central nervous system involvement
Why might the bladder be distended on a drug death autopsy
MDMA, amphetamine and other psycho-actives may cause urinary retention
List common opioids/opiates
heroin, morphine, pethidine, fentanyl, methadone, oxycodone, dihydrocodeine
Describe the aetiology of native valve endocarditis
Rheumatic valvular disease - primarily of mitral (most common)
Congenital heart disease (PDA, VSD, ToF)
Mitral valve prolapse with associated murmur
Degenerative heart disease such as calcified aortic stenosis, Marfan’s or syphillis
Infections - most commonly strep or staph
Does IVDU endocarditis occur due to underlying valve abnormalities
No
the valves are typically normal
Why are arterial thromboses more dangerous
Can occlude critical vessels resulting in infarction
May lead to MI or stroke
What causes carcinoid heart disease
Carcinoid syndrome - around 50% of patients will develop the heart effects
Neuroendocrine tumours in the gut secrete compounds such as serotonin
If there is significant liver pathology, these cannot be broken down and are carried to the heart where they cause damage
What is the preferred sample for death by carbon monoxide poisoning
Blood sample
List most common causes of IVDA infective endocarditis
Staph aureus is the most common organism
Also Group A, C, G streptococci and enterococci
Gram-negative organisms e.g P aeruginosa and the HACEK family
List the basic precautions taken during autopsy
Prevention of puncture wounds, cuts, and abrasions by safe handling of needles and sharp instruments.
Protection of existing wounds, skin lesions, conjunctiva, and mucous membranes with appropriate barriers.
Prevention of contamination of workers’ skin and clothing with appropriate barriers and hand washing.
Control of work surface contamination by containment and decontamination.
Safe disposal of contaminated waste.
Minimise aerosol production.
Limit the number of staff in the room at one time.
Where are lung samples taken from
Take approximately 2cm3 of tissue
Heroin has a higher affinity for the m-opioid receptor than its metabolites - true or false
False
It has a lower affinity
Therefore called a pro-drug as action comes mainly from metabolites
Give examples of radioactive based hazards from the body and explain how you reduce the risk
Some corpses will be slightly radioactive if just undergone therapeutic or diagnostic radiology procedures
Should be left until level has fallen (most used in diagnostic have short half lives). In these cases the risk of exposure is very low.
If the source cannot be removed a radiology specialist should be involved and levels should be measured
Which valve is most effected by endocarditis in SLE
Mitral valve
What are the major complications of endocarditis treatment
Post-treatment bacteraemia Relapse Valvular dysfunction Myocardial or septal abscesses Congestive heart failure Metastatic infection Embolic phenomenon Organ dysfunction resulting from immunological processes
Can blood clots be useful for toxicology
Yes
They may reflect drug and/or alcohol concentrations closer to the time of injury - act like time capsules as poorly perfused
Also good for documenting pre-existing drug use
What poses a risk of electrocution in autopsy
Poorly maintained electrical equipment - wet environment
ICDs
How are clots resorbed
Once stabilised, the body activates counter measures to break down and stop clotting
Tissue plasminogen Activator is released which converts plasminogen into plasmin which is capable of breaking down fibrin.
Also thrombomodulin which blocks coagulation cascade
Describe the features of the vegetations in endocarditis
They are friable, bulky, potentially destructive lesions containing fibrin, inflammatory cells & bacteria/other organisms
Can be single/multiple
May involve more than 1 valve
Describe the process of secondary haemostasis
Tissue factor is released by subendothelial cells, activating factor VII & the coagulation cascade resulting in the generation of thrombin from prothrombin
Thrombin cleaves fibrinogen into fibrin (strong, insoluble substance)
Fibrin consolidates the platelet plug by forming a fibrin mesh and further enhancing platelet aggregation
List the microscopic features of acute bacterial endocarditis
Vegetations that contain no fibroblasts and develop rapidly (no evidence of repair)
Large amounts of both polymorphonuclear leukocytes & organisms in an expanding area of necrosis
Rapidly produces spontaneous rupture of leaflets, papillary muscles and chordae tendinae
What is the main transmissible spongiform encephalopathy
Creutzfeldt-Jacobs disease
Caused by a prion
List common stimulant drugs
Cocaine, amphetamine, methamphetamine and amphetamine derivatives like ecstasy
What is morphine
Opioid agonist - greatest activity on m-receptor
Relatively long-acting
Hydrophilic
Describe how hair and fingernails taken for toxicology at autopsy
Hair samples should be collected before body is opened to avoid contamination
Cut from posterior vertex of head, as close as possible to scalp.
Specify cut end of hair bundle, then wrap in inert covering e.g. aluminium foil
Fingernails can be collected by clipping, or if necessary, by removal of entire nail.
What causes tricuspid insufficiency
L-sided cardiac pathologies
Congenital abnormalities
Pacemaker lead entrapment
Marfan’s
What causes arteriolar vasoconstriction in primary haemostasis
Reflex neurogenic mechanisms and the local release of vasoconstrictors such as endothelin
Temporary effect
If there is too much space in a toxicology container what should be considered
Oxidative loss due to air trapped in container and volatile drug evaporation
What is bile tested for in toxicology
Historically used in the determination of opiates in general and morphine in particular
May be used if nothing else is available
What causes arterial thrombosis
Atherosclerosis - plaque ruptures forming clot
Abnormal myocardial contractions (arrhythmias/MI)
Thrombophilia’s
Heparin
Prosthetic heart valves
Genetic conditions
How is heroin metabolised in the body
Rapidly enters the CNS
Metabolised into 6-acetylmorphine (6-MAM), 3-acetylmorphine (3-MAM; less potent), and morphine
List the common causes of prosthetic valve endocarditis
Early infection (just after surgery) is typically staph aureus and s. epidermidis
Also gram -ve bacilli and candida
Late infection is most commonly alpha haemolytic strep/enterococci or s. aureus
Other causes include Corynebacterium,non-enterococcal streptococci, fungi, Legionella, and the HACEK organisms
What does a positive 6-MAM test mean
It can only mean that the person has recently used heroin
Cannot be caused by prescription opiates
Describe how urine is taken for toxicology at autopsy
At least 20ml if possible Use of fluoride preservative encouraged. Undergoes immunoassay Collected by creating a nick in the upper anterior fundus, or by aspiration with 20ml needle and syringe. Always taken
How do you manage aortic and mitral insufficiency
Depends on the symptoms and ejection fractions
May consider valve replacement or repair
List the effects of cocaine on the GI tract
Causes gastroduodenal perforation
Causes accelerated atherosclerotic disease causing ischemic colitis and colonic perforation
May occlude the SMA
What can lung samples tell you in a drugs death case
Useful in assessment of volatile substance abuse or exposure
Describe the course of acute native valve endocarditis
Involves normal valves - does not need underlying structural damage
Has an aggressive course
Rapidly progressive in all patients
List the indications for surgery in cases of native valve endocarditis
Congestive heart failure refractory to standard medical therapy
Fungal IE
Persistent sepsis after 72 hours of appropriate antibiotic treatment
Recurrent septic emboli, especially after 2 weeks of antibiotic treatment
Rupture of an aneurysm of the sinus of Valsalva
Conduction disturbances caused by a septal abscess
Kissing infection of the anterior mitral leaflet in patients with IE of the aortic valve
What were the original uses of heroin
As an anti-tussive for patients with TB and asthma
What is haemostasis
The process by which clots form at the site of vascular injury, arresting bleeding and maintaining vascular patency
What are the potential complications of air embolism
Decompression sickness
Mental impairment / coma
Which valves are most effected by rheumatic heart disease
Mitral most common, followed by aortic and, rarely, tricuspid
Valves can be effected in isolation or combination
What pathology is associated with aortic valve prothesis
Local abscesses
Fistula formation
Valvular dehiscence
Give examples of chemical based hazards from the body
If the death was due to toxic chemical ingestion/exposure
e.g. Cyanide poisoning can covert to toxic gas in stomach
List the main effects of morphine
Analgesia Respiratory depression Reduced GI activity Miosis Euphoria
Describe how CSF is taken for toxicology at autopsy
Aspirate from cisterna magna (skin at junction of back of head & posterior neck)
Entry felt as a loss of resistance.
Can also be taken via standard percutaneous LP (between L1&2 after organ evisceration)
Or by inserting a needle connected to a sterile syringe into a lateral ventricle of brain
List the pathological features of the skin due to secondary infection from drug use
May have abscesses and necrotising fasciitis due to pyogenic bacterial infection
Can get ulceration due to bacterial and fungal infection of injection sites
Chronic suppurative infections of the injection sites can lead to systemic amyloidosis
How long does it take heroin concentration to reach its peak in the body
After 1-5 mins from IV and smoked route, and within 5 mins of intranasal and IM administration
List the histological features seen in the lungs following cannabis use
Goblet and reserve cell hyperplasia
Squamous metaplasia
Nuclear atypia, basement membrane thickening
Subepithelial inflammation
Brown pigment macrophages - more common in smokers
How can you reduce transmission of Hep B and C at autopsy
Hep B risk can minimised by vaccination which should be given to all healthcare workers
Sharps care
Should be carried out in a separate/isolated room with limited staff if possible
What can contaminate blood from the jugular venous system
Reflux from the upper thorax
How can deep vein thrombosis remain asymptomatic
Collateral veins open up to maintain blood flow
What is the most common type of valve disease
Aortic stenosis
in developed world
What is post-mortem redistribution
The movement of drugs after death along a concentration gradient
It is a non-uniform process
Starts around 1hr after death and continues as PM interval increases
Biggest changes occur in the first 24hrs
How can perivascular abscesses progress
Can extend into adjacent cardiac conduction tissues leading to heart block
If it interferes with the ventricular conduction system in the septum it may cause sudden cardiac death
When might hair and fingernail samples be taken
Hair is rare as no direct link to cause of death
Can be useful when investigating sexual offence prior to death (drug-facilitated), long-term drug compliance/abstinence, previous use in drug users with abstinence/loss of tolerance & relapse, and chronic heavy metal poisoning.
How can tolerance affect interpretation of toxicology results
What may seem like a toxic or fatal dose may have less clinical effect in a person who has developed tolerance.
Take history into context
Which drugs can cause rhabdomyolysis without muscle compression
Cocaine, ecstasy and heroin
When do mechanical valves most often get infected
Within the first 3 months of implantation
What is an embolism
A solid, liquid or gaseous mass carried by the blood to a site distal from its origin
The majority are dislodged thrombi
What is rheumatic heart disease
Chronic complication following acute rheumatic fever
Occurs in 30-50% of patients
Describe the morphology of arterial thromboses
Grow in retrograde against the direction of flow
Consist of a meshwork of lots of platelets, some red cells and degenerating white cells - crumbly
Superimposed on atherosclerosis
How do you reduce the risk of chemical exposure during autopsy
Room should be well ventilated
Formaldehyde levels monitored to remain below safe legal limits as can be irritant or cause respiratory disorders
What can injection site samples be tested for
May be useful for determining the type of substance that has been injected, such as insulin or heroin
What are the underlying causes of aortic regurgitation
Bicuspid valve RHD Endocarditis Aortic root dissection Connective tissue diseases Most commonly aetiology is unknown
What is heroin
A semi-synthetic opiate
Why does heroin have such a fast effect
Lipophilic properties allow it to cross the BBB rapidly
This gives the immediate action and more intense effect
What is the major causative agent in IVDU endocarditis
Staph aureus
List the management options for infective endocarditis
Treatment of congestive heart failure
Oxygen
Haemodialysis - may be required in patients with renal failure
Take blood culture
Antibiotic therapy - dependent on culture results
May use anti-coagulation but contraversial
What is in Virchow’s triad
Stasis of blood flow - increase endothelial dysfunction and bring platelets in contact
Hypercoagulability - genetic or acquired
Endothelial injury - enhances procoagulant molecules and limits anti- ones
Which infection hazard groups required labelling on corpse or sample
HG3 or 4
What must be considered when interpreting toxicology from a urine sample
Positive identification of drugs in urine indicates past drug use, but does not indicate when or how much was ingested.
Blood should be tested for analytes found in urine to interpret context of exposure, e.g. negative in urine but high concentration in blood might indicate an acute death due to drug ingestion
All autopsies and samples should be handled as if infectious - true or false
True
Use standard infection control at all times, even if not confirmed infection - e.g. safe sharps, PPE
What are the potential complications of septic embolism
Ischaemic Injury - due to occlusion
Infectious - potential abscess
What is the typical half life of morphine
1.8 hours in women and 2.9 in males
Half life doubles in cirrhotic patients
Not affected by renal failure
What are the potential complications of systemic embolism
75% travel to lower extremities
10% go to brain and cause stroke
Where do thrombi form in endocarditis
Deposited on the sides of the low-pressure sink that lies just beyond a narrowing or stenosis (Venturi effect)
In mitral insufficiency they form on the atrial surface of the valve
With aortic insufficiency they are located on ventricular side
Define late prosthetic valve endocarditis
Occurring 60 days or more after the valve implantation
Repeated dosing of oral morphine is more potent relative to repeated doses of IV morphine - true or false
True
Thought to be due to large accumulation of M6G as oral morphine undergoes extensive first pass metabolism
What are the most common sites of infection in endocarditis
Aortic and mitral valves
Right heart valves affected in IVDU
What is normorphine
N-demethylated product of morphine
About 5% of morphine dose converted to this
Low conc and less potent
In general what are the most common causative organisms of infective endocarditis
S. aureus Viridans group streptococci Coagulase-negative staphylococci Enterococcus spp S. bovis
How does ketamine affect the urinary tract
It causes cystitis
Presents with denudation of the uroepithelium, granulation tissue in lamina propria and lymphocytic and eosinophilic infiltrate
Can be haemorrhagic
What can liver samples be tested for in drug deaths
Used for screening not quantification
Particularly valuable for Tricyclic antidepressant interpretation as well as other drugs which are highly protein bound
What are bioprosthetic valves made of
Porcine or frozen human valves from deceased donors
How can synergy affect interpretation of toxicology results
One drug increases the effects of another, either by summation (alcohol and ether) or by potentiation
Must consider all substances together - how do they affect each other
How do you manage pulmonary stenosis
Monitoring only if mild
Percutaneous balloon pulmonary valvuloplasty
What are the risk factors for recurrent IE
IV drug use
a previous episode of IE
The presence of a prosthetic valve
Congenital heart disease
Describe non-infectious endocarditis
Caused by the deposition of small bland thrombi onto the valve leaflets
There is no damage to underlying structures and no inflammatory response
Which enzyme is most important in opioid metabolism
UGT2B7
Describe the macroscopic appearance of carcinoid heart disease
Glistening white plaques form on endocardial surface
Plaques are comprised of extracellular matrix, myofibroblasts, mast cells and lymphocyte
Describe the course of subacute native valve endocarditis
Affects abnormal heart valves
More indolent course and may extend over several months
What criteria is used to diagnose endocarditis
Modified Duke Criteria
How you reduce the risk from infected bodies during autopsy
Body should be washed with detergent and then antiseptic.
Place in a leakproof bag.
Mark known infected corpses
List potential hazards from the equipment during autopsy
Sharp instruments and needles
Contaminated equipment
Chemical exposure - e.g. formaldehyde for fixing samples
Electrocution
What is the main difference between the mitral and tricuspid valves
Mitral only has 2 cusps and papillary muscles
Tricuspid have 3 of each
Where are liver samples taken from and why
Deep in the right lobe
This site should be uncontaminated with bile and less affected by drug distribution from the stomach
Describe how the platelet plug forms
Damage to the endothelial wall exposes collagen
This causes endothelial cells to release Von Willebrand Factor and other proteins
These substances from a bridge between platelets and site of injury - platelets adhere to it
Platelets then secrete chemicals causing further platelet aggregation and vasoconstriction
This forms a platelet plug
What are the typical causative agents of acute native valve endocarditis
Staph aureus
Group B strep
What are the potential complications of pulmonary embolism
Sudden death
Acute right heart failure
Artery rupture – haemorrhage
Pulmonary hypertension -> RV failure
How do you manage tricuspid insufficiency
Medical management of heart failure
Valve replacement or annuloplasty if severe
How can metabolism affect interpretation of toxicology results
Metabolism can be affected by liver disease so levels interpreted differently
Oxidative pathways which are easily saturable are most affected
What is included in the ‘circumstances of death’ information
Witness statement Medical history Current medication/therapies Previous operations/interventions Alcohol and drug use Previous imprisonment (incl. dates) Blood borne virus status Family history If they have had recent tests then pathologist should be given results
Describe endocarditis embolism
The emboli fragments contain virulent organisms
They can form abscesses where they lodge
They also may go on to cause septic infarcts
How is morphine excreted
90% in the urine
10% in faeces
75% excreted as M3G, 10% as free morphine and the rest as M6G and other molecules
approx 87% excreted after 72hrs
Which antibiotics are used to treat MSSA endocarditis
Nafcillin
When collecting samples for genomic DNA analysis what is the goal
It is to collect tissue type with intact nuclei that doesn’t hinder tissue dissociation procedures.
How do you treat aortic stenosis
Valve replacement - either open surgery or TAVI
May do balloon valvuloplasty if patient is unstable
Which drugs have the greatest post-mortem redistribution
Highly protein bound drugs
Especially those contained within the major organs
Likely due to changes to proteins PM which causes release of the bound drugs - they can redistribute
Describe the general pathogenesis of infective endocarditis
All cases develop from a bacteremia (nosocomial or spontaneous) that delivers the organisms to the surface of the valve
Adherence of the organisms
Eventual invasion of the valvular leaflets
What are mechanical valves made of
Configurations of metal and ceramic
How can cocaine affect the kidneys
Can cause FSGS, renovascular disease, interstitial nephritis
What are the potential complications of retinal embolism
May be asymptomatic
Branch retinal artery occlusion
Central retinal artery occlusion
Vision problems
Describe laminar flow
This is how blood flows normally
Most blood constituents in the middle and plasma around the periphery
When might you see a ‘mushroom plume’ at autopsy
Plume of froth at the mouth due to pulmonary oedema
Common in opiate overdose
List potential hazards from the room during autopsy and explain how they can be avoided
Contaminated work surfaces
Disinfect all surfaces and floors
UV light can be used to decontaminate air and surfaces if necessary
Spills - risk of contamination or slips
Disinfect and dry all spills
Which areas of the heart are most susceptible to perivascular abscesses following endocarditis
Aortic valve & its adjacent annulus
Which side of the heart is most often affected in IVDU endocarditis
Right side - 70% of cases
50% of cases involves the tricuspid valve
List external signs of drug use seen on the chest
Spider naevi, caput medusa, haemorrhoids and abdominal distension as a result of liver failure
What pathological changes may be seen in the liver due to drug use
Most due to hep B and C or ethanol
Hep B/C cause triaditis – lymphocytic infiltration with a few plasma cells and neutrophils
Hep C can cause steatosis with a mixed macro/micro vesicular pattern
Skin infections from IV use can lead to amyloidosis
Which samples can be taken at autopsy for toxicology
Blood Urine Vitreous humor Gastric contents Bile CSF Hair and fingernails Sample from injection sites Lung tissue Bone marrow
What are the potential complications of amniotic embolism
Mortality rate 80%
Permanent neurological deficit in 85% of survivors
How does cocaine affect the heart
Enlarged hearts with interstitial fibrosis and perivascular fibrosis caused by catecholamine effect of cocaine
Accelerated atherosclerosis, coronary and aortic dissection and coronary thrombus in the young
Will increase the chances of an MI
Cocaine can cause a cardiomyopathy
Can cause sudden cardiac death with contraction band necrosis
Also seen in methamphetamine/amphetamine (without vascular effects)
Which heart valves are most commonly affected by valve diseases
Aortic and mitral
List the macroscopic features of infective endocarditis
Vegetations on the heart valves - may be single or multiple
May produce a ring abscess in the myocardium if the vegetations erode
May lead to septic emboli
What is the sample of choice for detecting and analysing drugs concentrations in PM
Blood
If patient was in hospital or had a blood test in the last days of life then this is the best sample - ante-mortem
Peripheral venous or arterial best PM sample
Which samples are taken for metabolic studies at autopsy
Liver, brain, kidney, cardiac + skeletal muscle and peripheral nerves can be used
Samples obtained soon after death
Can be used to diagnose inborn errors of metabolism
List the indications for surgery in cases of prosthetic valve endocarditis
Same as native valve but also includes:
Valvular dehiscence
Early PVE
What are fibroblast samples used for
Tissue culture
Then karyotyping, metabolic & enzyme assays, and diagnostic ultrastructural studies can be done
When are muscle samples taken at autopsy
Can be useful if internal organs are badly decomposed
Take from the psoas muscle
When does rheumatic fever typically occur
2-3 weeks after a group A strep pharyngitis
What does morphine bind to in the body
Mainly albumin
List the main sources of hazards from the body during autopsy
Aerosols Sharp injury from within the body Infection Radioactivity Implanted cardiac devices Chemical contamination Moving injury
Which drugs can cause changes in the testes
Cocaine and cannabinoids impair spermatogenesis through reduction in mature germinal cells, narrower tubules and shorter sperm producing epithelium
Cannabis can cause a non-seminoma testicular germ cell tumour
What factors impact the effect a drug has on an individual
Sex Age Body habitus Genotype Fast/slow metabolisms Empty/full stomach Concurrent substance Tolerance Dose & purity of drug.
Most patients with IVDA infective endocarditis typically have a history of heart disease or murmurs - true or false
False
2/3 have no history
If multiple autopsies are being performed which one should be done first
The highest risk/most infectious
This reduces risk of error due to fatigue
How can metabolism affect interpretation of toxicology results
Metabolism can be affected by liver disease so levels interpreted differently
Oxidative pathways which are easily saturable are most affected
What is MRSA endocarditis associated with
Previous hospitalisation
Long-term addiction
Non-prescribed antibiotic use
What are kidney samples useful for
Analysis of heavy metals
What is included in the functional unit of the AV valves
Valve leaflet - cusp
Chordae tendinea
Papillary muscles
What is included in the ‘scene of death’ information
Details of environment - indoors/outdoors, temp etc.
How body was discovered
Security
Place, posture and clothing
Presence/absence of needles, syringes, medicine containers and pills
Provisional description of the body, including injuries (if any)
Identity of person discovering the dead person
Describe how bile is taken for toxicology at autopsy
Aspirate from gall bladder (after tying it off) or directly from common bile duct
What are the potential complications of fat embolism
Fat embolism syndrome
What autopsy results can suggest drug packing
Presence of undigested pills in the cases/wrapping in the GI tract
High levels on toxicology due to rupture
Which sites see the greatest changes in drug concentrations post-mortem
The greatest increase is seen in blood at central sites such as vessels around major organs
Changes are highly site dependent
List the non-specific external signs of drug use
Malnourishment Recent injury/self harm Signs of resus Bright red hypostasis Scars and homemade tattoos Abnormal patterns of hypostasis
List the external signs of chronic drug use
Perforated nasal septum from snorting
Thrombophlebitis from injecting
Self harm and previous injury and bruising
Older needle marks - look all over, may have irregular scarring, hyperpigmentation and chronic sinuses
Which drug can cause black sputum
Cocaine
Which sites see the greatest changes in drug concentrations post-mortem
The greatest increase is seen in blood at central sites such as vessels around major organs
What is the last stage of haemostasis
Clot stabilization and resorption
Describe the risk of contracting transmissible spongiform encephalopathies at autopsy
Risk of transmission is lower, but the prions are much harder to kill.
Incidence is the same amongst mortuary staff as general population, again suggesting the risk is not that high
It can remain infective once dried down and is resistant to normal cleaning procedures
What are the chronic causes of mitral regurgitation
Mitral valve prolapse
Myxomatous degeneration of the mitral valve
Mitral annular calcification
Why is it unlikely for a thrombus to occur in the arterial system
It is high flow so pro-coagulant molecules are easily washed away
More turbulent blood flow - less stasis
However, may occur if there is underlying atherosclerosis
Describe the composition of vegetations in non-infective endocarditis
Made up of fibrin and platelets
Bland vegetations
How can heroin affect the kidneys
Can cause FSGS, interstitial nephritis and fibrosis
Will see plasma cell and lymphocyte infiltrates
List the potential complications of valve replacement surgery
Thromboembolism - occlusion of valve or emboli thrown off it
Infective endocarditis - increased risk of bacterial vegetation
Structural deterioration of bioprosthetic valve
Continued valve dysfunction e.g. with inadequate or fibrotic healing, valve-orifice disproportion
If you cant get a peripheral blood sample at autopsy where should you take it from
The heart - right chamber is preferable
Must label it as a cardiac sample
When do the complications of IE typically present
Usually within the first few weeks of IE onset
How does superficial vein thrombosis present
Overlying skin is inflamed
Pain, oedema, swelling and tenderness
Can feel like a hard cord under the skin
How can endocarditis cause death
Heart failure
Valvular damage due to the infection
Abscesses which involve the conducting system can lead to arrhythmia0 and sudden cardiac death
Septic emboli can lead to infarction and acute MI
Describe the effect of M3G
It is not an agonist of opioid receptors - has no narcotic activity
Highly water soluble
How does right sided IVDU endocarditis present
Fever Pleuritic chest pain Dyspnea Non-productive cough May or may not have a murmur
How do you reduce the risk from contaminated equipment during autopsy
All should be put in enzymatic cleaner, rinsed and then disinfected.
Known infected cases use the enzyme cleaner but then are rinsed and placed in bleach or glutaraldehyde.
Even things like the camera should be cleaned after use
List the most common risk factors for infective endocarditis
Most significant: residual valvular damage caused by a previous endocarditis
DM
Age
Use of anticoagulants and corticosteroids
3 times as common in males as in females
Surgical intervention to a pacemaker system
How can drug packing affect the GI tract
If the package ruptures it can lead to overdose - high levels on tox screen
Can perforate the bowel, cause mucosal discoloration and rarely ulceration
What can cause mitral stenosis
Most caused by RHD following rheumatic fever (rare in developed world but still prevalent elsewhere)
Other causes: calcification, carcinoid syndrome, use of serotonergic drugs, SLE and amyloidosis
How do you manage pulmonary insufficiency
Treatment of underlying cause
Medical management of heart failure
Valve replacement in severe cases
What are the atrioventricular valves
The valves found between the atria and ventricles - mitral and tricuspid
Close on first heart sound
What conditions may predispose you to aortic stenosis
Bicuspid aortic valves - may present earlier in life
RHD - more prone to calcification
Cardiac blood is particularly susceptible to drug concentration increases due to redistribution - true or false
True
Also susceptible due to cardiac muscle autolysis or trauma
How can you reduce transmission of HIV at autopsy
Should be carried out in a separate/isolated room with limited staff if possible
Can be inactivated by drying or disinfectant - virus doesn’t last well out of body
What are the risk factors of a pacemaker
Development of a postoperative hematoma
Infectious endocarditis
Inexperience of the surgeon
A preceding temporary transvenous pacing
What information must be collected prior to the autopsy
Info about the scene of death - environment, position etc.
Circumstances of death - witnesses, medical history etc.
Sources of the above information
Patient history
List the external signs of recent drug use
Powder and froth around mouth and nose Faecal and urine staining Vomitus Facial petechiae Recent bruising/injury Needle marks - look all over
How does valve insufficiency progress to heart failure
Increased atrial and ventricular filling pressures
This leads to cardiac hypertrophy and eventually congestive heart failure
Patients may be asymptomatic until this occurs
Which antibiotics are used to treat MRSA endocarditis
Vancomycin
List some of the potential sources for pre-autopsy information
If death in the community use GP notes or pre-hospital clinician report
If death in hospital get admission bloods, lab investigations, urine sample if possible and clinical notes
When do bioprosthetic valves most often get infected
Typically within 1 year
When are adipose tissue samples taken in drug deaths
When the presence of fat-soluble drugs or chlorinated hydrocarbons and other pesticides is suspected.
Is heroin hydrophilic or lipophilic
Highly lipophilic
Due to presence of 2 acetyl groups
More lipophilic than morphine
Name the leaflets of the pulmonary valve
anterior, left and right leaflets
What is bile tested for in toxicology
Historically used in the determination of opiates in general and morphine in particular
Which valvular disease gives a fish mouth appearance
Mitral stenosis
Where is morphine metabolised
Primarily in the liver
What are the pros and cons of mechanical valves
Pros – Typically long-lasting so unlikely to require further surgeries
Cons – Requires lifelong coagulation (currently with warfarin), audible clicking depending on design
Why might the bladder be empty on a drug death autopsy
Any drug that causes a seizure may
cause incontinence
What causes tricuspid stenosis
RHD (with mitral and aortic involvement)
Carcinoid syndrome
IE (especially among IVDU)
Anatomical abnormalities
Describe the appearance of post-mortem clots
Not attached to endothelium
Gelatinous, moist and shiny
Upper “chicken fat” portion is yellow and lower is dark red
Do not have lines of Zahn (differentiates from venous thrombi)
How are bacteria protected from the host response in pacemaker endocarditis
The growing layers of platelets and fibrin protect it from circulating neutrophils and other defenses
Lots of nutrients available
Organisms deep in the vegetation hibernate and are less susceptible to antibiotics that interfere with bacterial cell wall synthesis
Which type of venous thrombosis is most likely to embolise
Deep vein
List common sedative drugs
benzodiazepam and related drugs
How do you reduce the risk of sharps injury
Never recap a needle (most common cause of injury) and dispose immediately after use
Use blunt needles/blunt top scissors where possible
Apply traction with forceps or a cut resistant glove rather than a simple gloved hand
Describe how rheumatic fever damages the heart
Host mounts immune response to the RF
Antibodies and CD4+ T cells may recognise cardiac self-antigens as M antigens of group A streptococcus
This triggers complement activation and macrophage activity which damage the heart tissue Leads to formation of fibrous lesions
Describe how vitreous humor is taken for toxicology at autopsy
Collected from both eyes - can be put in the same container
Always taken
What is the difference between the pulmonary oedema seen in cocaine use and opiate overdose
Cocaine - the oedema is cardiogenic and so has a low protein count, doesn’t foam as much
Opiate - foams up causing mushroom plume
List the effects of cannabis on the lungs
Can cause a pneumopericardium, pneumomediastinum and pneumothorax as well as bullous disease
Can also cause a desquamative interstitial pneumonitis
Fibrosis and atelectasia of the lungs is also caused by cannabis
Combined with smoking increased COPD risk
How might the teeth be affected by cocaine use
Typically leads to poor dental hygiene and tooth damage
In which non-forensic cases are toxicology samples taken
Where death is very likely to be due to a drug
Where no cause of death is found at autopsy
Death by suicide/misadventure with the possibility of impaired reasoning
Where it is necessary to exclude toxicology as a likely cause of death
Any case where there is deprivation of liberty (e.g. when someone is held under supervision and not allowed to leave)
Where poor compliance may have contribute to death (e.g. anti-epileptic medication)
List external signs of drug use seen on the limbs
Peripheral oedema
Erythema over joints = hypothermia
Fungal endocarditis will have a negative blood culture - true or false
True
Describe the histology of the SL valves
Annulus is the same as AV
Have an endothelial lining – smooth on ventricular side, ridged on arterial side
Three distinct layers of connective tissue – lamina radialis, lamina spongiosa, lamina fibrosa
Can non-infective endocarditis cause emboli
Yes
Can go on to cause significant infarcts in the brain, heart, kidneys, and other organs
Define a ‘hazard’
A source or a situation that has the potential to cause harm
e.g. slippery floor or sharps
What are the clinical features of arterial thrombosis
Symptoms as dependent on site of occlusion/embolus
E.g. a stroke can cause one side of the face to droop, weakness in one side of the body and slurred speech
