Superior vena cava (SVC) obstruction is an oncological emergency caused by compression of the SVC and is most commonly associated with lung cancer.

Some causes of the condition include:
1. Common malignancies: non small cell lung cancer, lymphoma
2. Other malignancies: metastatic seminoma, Kaposi’s sarcoma, breast cancer
3. Aortic aneurysm
4. Mediastinal fibrosis

Clinical features of SVC obstruction include:
1. Dyspnoea: most common
2. Swelling of the face, neck, and arms: conjunctival and periorbital oedema may be seen
3. Headache: often worse in the morning
4. Visual disturbances
5. Pulseless jugular venous distension

Management options are:
1. General: dexamethasone, balloon venoplasty, stenting
2. Small cell lung cancer: chemotherapy and radiotherapy
3. Non small cell lung cancer: radiotherapy

There are two main reasons for using combinations of chemotherapeutic agents rather than single agents. First, different drugs exert their effects through different mechanisms, therefore, carefully combining them will increase the number of tumour cells killed in each cycle as well as decrease their chances of developing drug resistance. Second, there may be an even greater effect with drugs that are synergistic.

The patient is 74 years old. She has had a recent gastroscopy and colonoscopy. She has a history of angina and a right CEA. She is having colicky abdominal pain after meals and weight loss, which points to a possible diagnosis of chronic mesenteric ischemia. Thus, you would want to do a contrast-enhanced CT scan of the abdomen to look for this. A 24 hour cardiac monitor would also be helpful to look for any abnormal rhythm that could be a potential aetiology of her disease.

Severe vitamin C deficiency results in scurvy, a disorder characterized by hemorrhagic manifestations and abnormal osteoid and dentin formation.
Vitamin C plays a role in collagen, carnitine, hormone, and amino acid formation. It is essential for bone and blood vessel health and wound healing and facilitates recovery from burns. Vitamin C is also an antioxidant, supports immune function, and facilitates the absorption of iron (see table Sources, Functions, and Effects of Vitamins).
Dietary sources of vitamin C include citrus fruits, tomatoes, potatoes, broccoli, strawberries, and sweet peppers. (See also Overview of Vitamins.)

Cystinuria is strongly suspected because of the recurrent passing of cystine stones and otherwise non-remarkable medical history of this young adult patient. Like Cystinuria, all the conditions listed are also inherited disorders, however, the other differentials usually present in the early years of childhood, usually with failure to thrive.

Methyldopa is the drug of first choice for the control of mild to moderate hypertension in pregnancy. Labetalol is also considered as a first line drug for hypertension in pregnancy. Calcium channel blockers and hydralazine are considered as second line drugs. Beta-blockers (except labetalol), angiotensin receptor blockers, angiotensin-converting enzyme inhibitors and thiazides are not recommended.

In the petrous temporal bone the facial nerve produces three branches:
1. The greater petrosal nerve, which transmits preganglionic parasympathetic fibres to the sphenopalatine ganglion. These postganglionic fibres supply the lacrimal gland and the glands in the nasal cavity;
2. The nerve to stapedius;
3. Parasympathetic fibres to the submandibular and sublingual glands and taste fibres from the anterior two-thirds of the tongue.

Clozapine can cause neutropenia or agranulocytosis.

Clozapine is an atypical antipsychotic used in the treatment of schizophrenia, and in patients who are intolerant to, or unresponsive to other antipsychotics.

It is a weak D2-receptor and D1-receptor blocking activity, with noradrenolytic, anticholinergic, and antihistaminic properties.

Many antipsychotic drugs can occasionally cause bone marrow depression, but agranulocytosis is particularly associated with clozapine.

Other side effects include:
Hypotension, tachycardia
Fever, sedation, seizures (with high doses)
Appetite increase
Constipation
Heartburn
Weight gain
Extrapyramidal symptoms
Agranulocytosis
Neuroleptic malignant syndrome

Occupational asthma (OA) could be divided into a nonimmunological, irritant-induced asthma and an immunological, allergy-induced asthma. In addition, allergy-induced asthma can be caused by two different groups of agents: high molecular weight proteins (>5,000 Da) or low molecular weight agents (<5,000 Da), generally chemicals like the isocyanates.
Isocyanates are very reactive chemicals characterized by one or more isocyanate groups (–N=C=O). The main reactions of this chemical group are addition reactions with ethanol, resulting in urethanes, with amines (resulting in urea derivates) and with water. Here, the product is carbamic acid which is not stable and reacts further to amines, releasing free carbon dioxide.

Diisocyanates and polyisocyanates are, together with the largely nontoxic polyol group, the basic building blocks of the polyurethane (PU) chemical industry, where they are used solely or in combination with solvents or additives in the production of adhesives, foams, elastomers, paintings, coatings and other materials.

The complex salts of platinum are one of the most potent respiratory sensitising agents having caused occupational asthma in more than 50% of exposed workers. Substitution of ammonium hexachlor platinate with platinum tetra amine dichloride in the manufacture of catalyst has controlled the problem in the catalyst industry. Ammonium hexachlorplatinate exposure still occurs in the refining process.

Rosin based solder flux fume is produced when soldering. This fume is a top cause of occupational asthma.

Bakeries, flour mills and kitchens where flour dust and additives in the flour are a common cause of occupational asthma.

Cadmium was not found to cause occupational asthma.

Osteoblastic (or sclerotic) bone metastases, characterized by deposition of new bone, present in prostate cancer, carcinoid, small cell lung cancer, Hodgkin lymphoma or medulloblastoma.

Lithium acts by:
– I inhibiting postsynaptic D2 receptor super sensitivity
– Altering cation transport in nerve and muscle cells and influencing reuptake of serotonin or norepinephrine
– Inhibiting phosphatidylinositol cycle second messenger systems

The NICE guidelines for depression and bipolar disorder both recommend Lithium as an effective treatment; patients who take lithium should have regular blood tests to monitor the amount of lithium in their blood (every 3 months), and to make sure the lithium has not caused any problems with their kidneys or thyroid (every 6 months).

Lithium adverse effects include:
– Leucocytosis (most patients) which is when the white cells are above the normal range in the blood.
– Polyuria/polydipsia (30-50%)
– Dry mouth (20-50%)
– Hand tremor (45% initially, 10% after 1 year of treatment)
– Confusion (40%)
– Decreased memory (40%)
– Headache (40%)
– Muscle weakness (30% initially, 1% after 1 year of treatment)
– Electrocardiographic (ECG) changes (20-30%)
– Nausea, vomiting, diarrhoea (10-30% initially, 1-10% after 1-2 years of treatment)
– Hyperreflexia (15%)
– Muscle twitch (15%)
– Vertigo (15%)

Furosemide is a loop diuretic that is known to have significant ototoxicity side-effects although the mechanism is not fully known.

Acute angle closure glaucoma is associated with hypermetropia, whereas primary open-angle glaucoma is associated with myopia. Glaucoma is a group of eye disorders characterised by optic neuropathy due, in the majority of patients, to raised intraocular pressure (IOP). It is now recognised that a minority of patients with raised IOP do not have glaucoma and vice versa.

Age of the patient, headache only on one side, and loss of vision on that side suggest temporal arteritis, also known as giant cell arteritis. The laboratory hallmark of this condition is a raised ESR.

Urobiligen is produced by the action of bacteria on bilirubin in the intestine. As a reminder, unconjugated bilirubin becomes conjugated in the hepatocyte. Conjugated bilirubin goes through enterohepatic circulation. About half of the urobiligen is reabsorbed and excreted by the kidneys in the urine. The rest is converted to stercobilinogen –> stercobilin, which is excreted in stool, giving it its brown colour.

The walls of the ascending limb of the loop of Henle are not permeable to water. The tubular fluid thus becomes increasingly dilute as it ascends toward the cortex, whereas the interstitial fluid around the loops of Henle in the medulla becomes increasingly more concentrated.

The ascending limb actively reabsorbs NaCl but has an extremely low transepithelial osmotic water permeability, even in the presence of vasopressin. This combination of NaCl reabsorption without water reabsorption serves two vital functions: it provides NaCl to increase the osmolality of the medullary interstitium, tubules, vasculature, and collecting ducts; and it dilutes the luminal fluid within the thick ascending limb.

The prompt is suggestive of acute appendicitis. The Alvarado score is a clinical scoring system used to determine the likelihood of appendicitis, so this is the correct answer. A score greater than 6 is generally considered at risk for having acute appendicitis. It has 8 different criteria included (symptoms, signs, and lab results) and divides patients into appendicitis unlikely, possible, probable, and definite. The Center Score is a score to access the likelihood that pharyngitis is due to Strep. The Child-Pugh score predicts prognosis in liver cirrhosis. The Glasgow score is two different scores– the Glasgow coma score in trauma, which estimates level of consciousness, essentially, and The Glasgow Imrie Criteria which determines the severity of acute pancreatitis based on 8 lab values. The MELD score predicts the severity of end-stage liver disease.

Bronchiectasis is a long-term condition where the airways of the lungs become abnormally widened, leading to a build-up of excess mucus that can make the lungs more vulnerable to infection. The most common symptoms of bronchiectasis include:
– a persistent productive cough
– breathlessness.

The 3 most common causes in the UK are:
– a lung infection in the past, such as pneumonia or whooping cough, that damages the bronchi
– underlying problems with the immune system (the body’s defence against infection) that make the bronchi more vulnerable to damage from an infection
– allergic bronchopulmonary aspergillosis (ABPA) – an allergy to a certain type of fungi that can cause the bronchi to become inflamed if spores from the fungi are inhaled

Allergic bronchopulmonary aspergillosis (ABPA) is a form of lung disease that occurs in some people who are allergic to Aspergillus. With ABPA, this allergic reaction causes the immune system to overreact to Aspergillus leading to lung inflammation. ABPA causes bronchospasm (tightening of airway muscles) and mucus build-up resulting in coughing, breathing difficulty and airway obstruction.

Treatment of ABPA aims to control inflammation and prevent further injury to your lungs. ABPA is a hypersensitivity reaction that requires treatment with oral corticosteroids. Inhaled steroids are not effective. ABPA is usually treated with a combination of oral corticosteroids and anti-fungal medications. The corticosteroid is used to treat inflammation and blocks the allergic reaction. Examples
of corticosteroids include: prednisone, prednisolone or methylprednisolone. Inhaled corticosteroids alone – such as used for asthma treatment – are not effective in treating ABPA. Usually treatment with an oral corticosteroid is needed for months.

The second type of therapy used is an anti-fungal medication, like itraconazole and voriconazole. These medicines help kill Aspergillus so that it no longer colonizes the airway. Usually one of these drugs is given for at least 3 to 6 months. However, even this treatment is not curative and can have side effects.

Obsessive-Compulsive Disorder (OCD) is a common, chronic and long-lasting disorder in which a person has uncontrollable, reoccurring thoughts (obsessions) and behaviours (compulsions) that he or she feels the urge to repeat over and over.
People with OCD may have symptoms of obsessions, compulsions, or both. These symptoms can interfere with all aspects of life, such as work, school, and personal relationships.

Obsessions are repeated thoughts, urges, or mental images that cause anxiety. Common symptoms include:
Fear of germs or contamination
Unwanted forbidden or taboo thoughts involving sex, religion, and harm
Aggressive thoughts towards others or self
Having things symmetrical or in a perfect order

Compulsions are repetitive behaviours that a person with OCD feels the urge to do in response to an obsessive thought. Common compulsions include:
-Excessive cleaning and/or handwashing
-Ordering and arranging things in a particular, precise way
-Repeatedly checking on things, such as repeatedly checking to see if the door is locked or that the oven is off
-Compulsive counting

Research also shows that a type of CBT called Exposure and Response Prevention (ERP) is effective in reducing compulsive behaviours in OCD, even in people who did not respond well to SRI medication. ERP has become the first-line psychotherapeutic treatment for OCD

The use of nitrates and nicorandil concomitantly with sildenafil citrate is contraindicated.

Sildenafil (Viagra) is a phosphodiesterase type V inhibitor used in the treatment of impotence.

Contraindications
– Patients taking nitrates and related drugs such as nicorandil
– Hypotension
– Recent stroke or myocardial infarction (NICE recommend waiting 6 months)

Side-effects:
Visual disturbances e.g. cyanopsia, non-arthritic anterior ischaemic Neuropathy
Nasal congestion
Flushing
Gastrointestinal side-effects
Headache

High Altitude Cerebral Oedema (HACE) is a severe and potentially fatal manifestation of high altitude illness and is often characterized by ataxia, fatigue, and altered mental status. HACE is often thought of as an extreme form/end-stage of Acute Mountain Sickness (AMS). Although HACE represents the least common form of altitude illness, it may progress rapidly to coma and death as a result of brain herniation within 24 hours, if not promptly diagnosed and treated.

HACE generally occurs after 2 days above 4000m but can occur at lower elevations (2500m) and with faster onset. Some, but not all, individuals will suffer from symptoms of AMS such as headache, insomnia, anorexia, nausea prior to transitioning to HACE. Some may also have concomitant High Altitude Pulmonary Oedema (HAPE). HACE in isolation is rare, but the absence of concomitant HAPE or symptoms of AMS prior to deterioration does not rule-out the presence of HACE.

Most cases develop as a progression of AMS and will include a history of recent ascent to altitude and prior complaints/findings of AMS including a headache, fatigue, nausea, insomnia, and/or light-headedness. Some may also have signs/symptoms of HAPE. Transition to HACE is heralded by signs of encephalopathy including ataxia (usually the earliest clinical finding) and altered mentation which may range from mild to severe. Other symptoms may include a more severe headache, difficulty speaking, lassitude, a decline in the level of consciousness, and/or focal neurological deficits or seizures.

The mainstay of treatment is the immediate descent of at least 1000m or until symptoms improve. If descent is not an option, one may use a portable hyperbaric chamber and/or supplemental oxygen to temporize illness, but this should never replace or delay evaluation/descent when possible. If available, dexamethasone 8mg for one dose, followed by 4mg every 6 hours should be given to adults via PO, IM, or IV routes.
Acetazolamide has proven to be beneficial in only a single clinical study. The suggested dosing regimen for Acetazolamide is 250 mg PO, given twice daily. Though effective in alleviating or temporizing symptoms, none of the adjunct treatment modalities are definitive or a replacement for an immediate descent.

Azathioprine therapy can cause acute myelosuppression. Toxicity is in part caused by the incorporation of azathioprine-derived 6-thioguanine nucleotides (6-TGN) into deoxyribonucleic acid (DNA). The enzyme thiopurine methyltransferase (TPMT) plays an important role in azathioprine catabolism.

The patient has spinal cord compression until proven otherwise. Urgent assessment is required.

Spinal cord compression is an oncological emergency and affects up to 5% of cancer patients. Extradural compression accounts for the majority of cases, usually due to vertebral body metastases. One of the most common causes of spinal cord compression is osteoarthritis. It is also more commonly seen in patients with lung, breast, or prostate cancer.

Clinical features include:
1. Back pain: the earliest and most common symptom, may worsen on lying down or coughing
2. Lower limb weakness
3. Sensory changes: sensory loss and numbness
4. Neurological signs: depending on the level of the lesion.
Lesions above L1 usually result in upper motor neurone signs in the legs. Lesions below L1 usually cause lower motor neurone signs in the legs and perianal numbness. Tendon reflexes are increased below the level of the lesion and absent at the level of the lesion.

Management options are:
1. High-dose oral dexamethasone
2. Urgent MRI for consideration of radiotherapy or surgery

The most probable diagnosis in this patient is conversion disorder.

There may be underlying tension regarding her musical career which could be manifesting as apparent limb weakness.

Conversion disorder typically involves loss of motor or sensory function. The patient doesn’t consciously feign the symptoms (factitious disorder) or seek material gain (malingering). Patients may be indifferent to their apparent disorder – la belle indifference – although this has not been backed up by studies.

Other options:
Unexplained symptoms
There are a wide variety of psychiatric terms for patients who have symptoms for which no organic cause can be found:

Somatization disorder
Multiple physical symptoms present for at least 2 years
the patient refuses to accept reassurance or negative test results

Hypochondriacal disorder
The persistent belief in the presence of an underlying serious disease, e.g. cancer.
The patient again refuses to accept reassurance or negative test results

Dissociative disorder
Dissociation is a process of ‘separating off’ certain memories from normal consciousness
Unlike conversion disorder, it involves psychiatric symptoms e.g. amnesia, fugue, stupor
Dissociative identity disorder (DID) is the new term for multiple personality disorder as is the most severe form of dissociative disorder

Munchausen’s syndrome
Also known as factitious disorder
The intentional production of physical or psychological symptoms

Malingering
Fraudulent simulation or exaggeration of symptoms with the intention of financial or another gain.

Of all the listed options, gastric cancer is least likely to be inherited.

The above mentioned tumours are ruled out as explained below:
1. Breast and Ovarian cancers: Between 5%–10% of all breast cancers are thought to be hereditary. Mutation in the BRCA1 and BRCA2 genes also increase the risk of ovarian cancer.

2. Colorectal and Endometrial cancers: About 5% of cases of colorectal cancer are caused by hereditary non-polyposis colorectal carcinoma (HNPCC) and 1% are due to familial adenomatous polyposis. Women who have HNPCC also have a markedly increased risk of developing endometrial cancer—around 5% of endometrial cancers occur in women with this risk factor.

Based on the given clinical scenario, the most probable diagnosis in this patient is acute paranoid schizophrenia.

Schizophrenia is a functional psychotic disorder characterized by the presence of delusional beliefs, hallucinations, and disturbances in thought, perception, and behaviour.

Clinical features:
Schneider’s first-rank symptoms may be divided into auditory hallucinations, thought disorders, passivity phenomena, and delusional perceptions:

Auditory hallucinations of a specific type:
Two or more voices discussing the patient in the third person
Thought echo
Voices commenting on the patient’s behaviour

Thought disorder:
Thought insertion
Thought withdrawal
Thought broadcasting

Passivity phenomena:
Bodily sensations being controlled by external influence
Actions/impulses/feelings – experiences which are imposed on the Individual or influenced by others

Other features of schizophrenia include
Impaired insight (a feature of all psychoses)
Incongruity/blunting of affect (inappropriate emotion for circumstances)
Decreased speech
Neologisms: made-up words
Catatonia
Negative symptoms: incongruity/blunting of affect, anhedonia (inability to derive pleasure), alogia (poverty of speech), avolition (poor motivation).

Treatment:
For the initial treatment of acute psychosis, it is recommended to commence an oral second-generation antipsychotics such as aripiprazole, olanzapine, risperidone, quetiapine, etc.
Once the acute phase is controlled, switching to a depot preparation like aripiprazole, paliperidone, zuclopenthixol, fluphenazine, haloperidol, pipotiazine, or risperidone is recommended.
Cognitive-behavioural therapy (CBT) and the use of art and drama therapies help counteract the negative symptoms of the disease, improve insight, and assist relapse prevention.
Clozapine is used in case of treatment resistance.

Oestrogen therapy reduces plasma levels of LDL cholesterol and increases levels of HDL cholesterol. It can improve endothelial vascular function, however, it also has adverse physiological effects, including increasing the plasma levels of triglycerides (small dense LDL particles). Therefore, although HRT may have direct beneficial effects on cardiovascular outcomes, these effects may be reduced or balanced by the adverse physiological effects.

The patient is most likely to have Bulimia nervosa. A young girl with a low body mass contributes to the low urea. Hypokalaemia and hyponatraemia are due to vomiting. Her urine sodium is also low.
– In Addison’s diseases, there are low levels of sodium and high levels of potassium in the blood. In acute adrenal crisis: The most consistent finding is elevated blood urea nitrogen (BUN) and creatinine. Urinary and sweat sodium also may be elevated.
– In Syndrome of Inappropriate Antidiuretic Hormone Secretion (SIADH) there is hyponatremia with corresponding hypo-osmolality, continued renal excretion of sodium, urine less than maximally dilute and absence of clinical evidence of volume depletion.

The hazard ratio describes the relative risk of the complication based on comparison of event rates.

Hazard ratios have also been used to describe the outcome of therapeutic trials where the question is to what extent treatment can shorten the duration of the illness. However, the hazard ratio, a type of relative risk, does not always accurately portray the degree of abbreviation of the illness that occurred. In these circumstances, time-based parameters available from the time-to-event curve, such as the ratio of the median times of the placebo and drug groups, should be used to describe the magnitude of the benefit to the patient. The difference between hazard-based and time-based measures is analogous to the odds of winning a race and the margin of victory. The hazard ratio is the odds of a patient’s healing faster under treatment but does not convey any information about how much faster this event may occur.