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Question 1
Incorrect
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A 20-year-old man presents to the emergency department with diabetic ketoacidosis. After early treatment, an arterial blood gas is taken, which shows the following results.
ABG result - temperature 35.0 ºC:
pH 7.30 (7.35 - 7.45)
PaCO2 3.5 kPa (4.7 - 6.0)
PaO2 10 kPa (11 - 13)
HCO3- 16 mEq/L (22 - 26)
Na+ 138 mmol/L (135 - 145)
K+ 3.3 mmol/L (3.5 - 5.0)
What physiological change is occurring in this patient?Your Answer: Hypothermia is causing a decreased affinity of haemoglobin for oxygen
Correct Answer: Metabolic acidosis is causing a decreased affinity of haemoglobin for oxygen
Explanation:In acidosis, the oxyhaemoglobin dissociation curve shifts to the right, indicating a decrease in affinity of haemoglobin for oxygen. This is due to an increase in the number of [H+] ions, reflecting greater metabolic activity. Low [H+] levels cause a shift to the left. The low HCO3- in this patient can be explained by metabolic acidosis, but it does not cause a shift in the oxyhaemoglobin dissociation curve. Hypokalaemia may be a result of treatment for diabetic ketoacidosis, but it does not cause a shift in the oxygen dissociation curve. When temperature increases, the oxyhaemoglobin dissociation curve also shifts to the right, causing a decrease in haemoglobin affinity for oxygen. Hypothermia causes a shift to the left, indicating an increased affinity of haemoglobin for oxygen.
Understanding the Oxygen Dissociation Curve
The oxygen dissociation curve is a graphical representation of the relationship between the percentage of saturated haemoglobin and the partial pressure of oxygen in the blood. It is not influenced by the concentration of haemoglobin. The curve can shift to the left or right, indicating changes in oxygen delivery to tissues. When the curve shifts to the left, there is increased saturation of haemoglobin with oxygen, resulting in decreased oxygen delivery to tissues. Conversely, when the curve shifts to the right, there is reduced saturation of haemoglobin with oxygen, leading to enhanced oxygen delivery to tissues.
The L rule is a helpful mnemonic to remember the factors that cause a shift to the left, resulting in lower oxygen delivery. These factors include low levels of hydrogen ions (alkali), low partial pressure of carbon dioxide, low levels of 2,3-diphosphoglycerate, and low temperature. On the other hand, the mnemonic ‘CADET, face Right!’ can be used to remember the factors that cause a shift to the right, leading to raised oxygen delivery. These factors include carbon dioxide, acid, 2,3-diphosphoglycerate, exercise, and temperature.
Understanding the oxygen dissociation curve is crucial in assessing the oxygen-carrying capacity of the blood and the delivery of oxygen to tissues. By knowing the factors that can shift the curve to the left or right, healthcare professionals can make informed decisions in managing patients with respiratory and cardiovascular diseases.
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This question is part of the following fields:
- Respiratory System
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Question 2
Incorrect
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A 35-year-old female presents with recurrent episodes of severe vertigo that have been disabling. She experiences these episodes multiple times a day, with each one lasting for about 10-20 minutes. Along with the vertigo, she also experiences ringing in both ears, nausea, and vomiting. She has noticed a change in her hearing in both ears, with difficulty hearing at times and normal hearing at other times. Additionally, she reports increased pressure in her ears. During the examination, you notice a painless rash behind her ear that has been present for many years.
What is the most likely diagnosis?Your Answer: Vestibular neuronitis
Correct Answer: Meniere’s disease
Explanation:Suspect Meniere’s disease in a patient presenting with vertigo, tinnitus, and fluctuating sensorineural hearing loss. Acoustic neuroma would present with additional symptoms such as facial numbness and loss of corneal reflex. Herpes Zoster Oticus (Ramsey Hunt syndrome) would present with facial palsy and a painless rash. Vestibular neuronitis would have longer episodes of vertigo, nausea, and vomiting, but no hearing loss. Benign paroxysmal positional vertigo would have brief episodes of vertigo after sudden head movements.
Meniere’s disease is a condition that affects the inner ear and its cause is unknown. It is more commonly seen in middle-aged adults but can occur at any age and affects both men and women equally. The condition is characterized by the excessive pressure and progressive dilation of the endolymphatic system. The main symptoms of Meniere’s disease are recurrent episodes of vertigo, tinnitus, and sensorineural hearing loss. Vertigo is usually the most prominent symptom, but patients may also experience a sensation of aural fullness or pressure, nystagmus, and a positive Romberg test. These episodes can last from minutes to hours and are typically unilateral, but bilateral symptoms may develop over time.
The natural history of Meniere’s disease is that symptoms usually resolve in the majority of patients after 5-10 years. However, most patients will be left with some degree of hearing loss, and psychological distress is common. ENT assessment is required to confirm the diagnosis, and patients should inform the DVLA as the current advice is to cease driving until satisfactory control of symptoms is achieved. Acute attacks can be managed with buccal or intramuscular prochlorperazine, and admission to the hospital may be required. Prevention strategies include the use of betahistine and vestibular rehabilitation exercises, which may be beneficial.
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This question is part of the following fields:
- Respiratory System
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Question 3
Incorrect
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During a schoolyard brawl a boy is hit in the chest. The stick passes through the posterior mediastinum (from left to right). Which one of the following structures is least likely to be injured?
Your Answer: Descending thoracic aorta
Correct Answer: Arch of the azygos vein
Explanation:The azygos vein’s arch is located within the middle mediastinum.
The mediastinum is the area located between the two pulmonary cavities and is covered by the mediastinal pleura. It extends from the thoracic inlet at the top to the diaphragm at the bottom. The mediastinum is divided into four regions: the superior mediastinum, middle mediastinum, posterior mediastinum, and anterior mediastinum.
The superior mediastinum is the area between the manubriosternal angle and T4/5. It contains important structures such as the superior vena cava, brachiocephalic veins, arch of aorta, thoracic duct, trachea, oesophagus, thymus, vagus nerve, left recurrent laryngeal nerve, and phrenic nerve. The anterior mediastinum contains thymic remnants, lymph nodes, and fat. The middle mediastinum contains the pericardium, heart, aortic root, arch of azygos vein, and main bronchi. The posterior mediastinum contains the oesophagus, thoracic aorta, azygos vein, thoracic duct, vagus nerve, sympathetic nerve trunks, and splanchnic nerves.
In summary, the mediastinum is a crucial area in the thorax that contains many important structures and is divided into four regions. Each region contains different structures that are essential for the proper functioning of the body.
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This question is part of the following fields:
- Respiratory System
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Question 4
Incorrect
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A 28-year-old man is found on his bathroom floor next to needles and syringes and is brought into the hospital. He has a Glasgow coma score of 10 and a bedside oxygen saturation of 88%. On physical examination, he has pinpoint pupils and needle track marks on his left arm. His arterial blood gases are as follows: PaO2 7.4 kPa (11.3-12.6), PaCO2 9.6 kPa (4.7-6.0), pH 7.32 (7.36-7.44), and HCO3 25 mmol/L (20-28). What do these results indicate?
Your Answer: Acute type I respiratory failure
Correct Answer: Acute type II respiratory failure
Explanation:Opiate Overdose
Opiate overdose is a common occurrence that can lead to slowed breathing, inadequate oxygen saturation, and CO2 retention. This classic picture of opiate overdose can be reversed with the use of naloxone. The condition is often caused by the use of illicit drugs and can have serious consequences if left untreated.
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This question is part of the following fields:
- Respiratory System
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Question 5
Incorrect
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A 65-year-old man visited his family doctor with a persistent cough that has been bothering him for the last six months. He complains of coughing up clear sputum and how it has been affecting his daily life. He has also noticed that he gets short of breath more easily and cannot keep up with his grandchildren. He has a medical history of well-controlled diabetes and dyslipidemia. He attended a smoking cessation program a few months ago, but he finds it challenging to quit smoking after smoking a pack of cigarettes a day for the past 40 years. During the examination, the doctor hears bilateral wheezing with some crackles. The doctor expresses concerns about a possible lung disease due to his long history of smoking and refers him for a pulmonary function test. What is likely to be found during the test?
Your Answer: The FEV1/FVC ratio is lower than normal due to an increase in FVC
Correct Answer: The FEV1/FVC ratio is lower than normal as there is a larger decrease in FEV1 than FVC
Explanation:The patient’s prolonged smoking history and current symptoms suggest a diagnosis of chronic bronchitis and possibly emphysema, both of which are obstructive lung diseases. These conditions cause air to become trapped in the lungs, making it difficult to breathe out. Pulmonary function tests typically show a greater decrease in FEV1 than FVC in obstructive lung diseases, resulting in a lower FEV1/FVC ratio (also known as the Tiffeneau-Pinelli index). This is different from restrictive lung diseases, which may sometimes show an increase in the FEV1/FVC ratio due to a larger decrease in FVC than FEV1. Chest X-rays may reveal hyperinflated lungs in patients with obstructive lung diseases. An increase in FEV1 may occur in healthy individuals after exercise training or in patients with conditions like asthma after taking medication. Restrictive lung diseases, such as pneumoconioses, hypersensitivity pneumonitis, and idiopathic pulmonary fibrosis, are typically associated with a decrease in the FEV1/FVC ratio.
Understanding Pulmonary Function Tests
Pulmonary function tests are a useful tool in determining whether a respiratory disease is obstructive or restrictive. These tests measure various aspects of lung function, such as forced expiratory volume in one second (FEV1) and forced vital capacity (FVC). By analyzing the results of these tests, doctors can diagnose and monitor conditions such as asthma, COPD, pulmonary fibrosis, and neuromuscular disorders.
In obstructive lung diseases, such as asthma and COPD, the FEV1 is significantly reduced, while the FVC may be reduced or normal. The FEV1% (FEV1/FVC) is also reduced. On the other hand, in restrictive lung diseases, such as pulmonary fibrosis and asbestosis, the FEV1 is reduced, but the FVC is significantly reduced. The FEV1% (FEV1/FVC) may be normal or increased.
It is important to note that there are many conditions that can affect lung function, and pulmonary function tests are just one tool in diagnosing and managing respiratory diseases. However, understanding the results of these tests can provide valuable information for both patients and healthcare providers.
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This question is part of the following fields:
- Respiratory System
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Question 6
Incorrect
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A senior woman with a history of chronic obstructive pulmonary disease (COPD) arrives at the hospital complaining of worsening shortness of breath and a productive cough. As part of the initial evaluation, a chest X-ray is requested.
What radiographic feature would you anticipate observing on her chest X-ray?Your Answer: Pleural effusion
Correct Answer: Flattened diaphragm
Explanation:The diaphragm of patients with COPD often appears flattened on a chest X-ray due to the chronic expiratory airflow obstruction causing dynamic hyperinflation of the lungs. Pleural effusions are commonly associated with infection, malignancy, or heart failure, while empyema is a result of pus accumulation in the pleural space caused by an infection.
Understanding COPD: Symptoms and Diagnosis
Chronic obstructive pulmonary disease (COPD) is a common medical condition that includes chronic bronchitis and emphysema. Smoking is the leading cause of COPD, and patients with mild disease may only need occasional use of a bronchodilator, while severe cases may result in frequent hospital admissions due to exacerbations. Symptoms of COPD include a productive cough, dyspnea, wheezing, and in severe cases, right-sided heart failure leading to peripheral edema.
To diagnose COPD, doctors may recommend post-bronchodilator spirometry to demonstrate airflow obstruction, a chest x-ray to check for hyperinflation, bullae, and flat hemidiaphragm, and to exclude lung cancer. A full blood count may also be necessary to exclude secondary polycythemia, and body mass index (BMI) calculation is important. The severity of COPD is categorized using the FEV1, with a ratio of less than 70% indicating airflow obstruction. The grading system has changed following the 2010 NICE guidelines, with Stage 1 – mild now including patients with an FEV1 greater than 80% predicted but with a post-bronchodilator FEV1/FVC ratio of less than 0.7. Measuring peak expiratory flow is of limited value in COPD, as it may underestimate the degree of airflow obstruction.
In summary, COPD is a common condition caused by smoking that can result in a range of symptoms and severity. Diagnosis involves various tests to check for airflow obstruction, exclude lung cancer, and determine the severity of the disease.
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This question is part of the following fields:
- Respiratory System
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Question 7
Incorrect
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Which of the following laryngeal tumors is unlikely to spread to the cervical lymph nodes?
Your Answer: Subglottic
Correct Answer: Glottic
Explanation:The area of the vocal cords lacks lymphatic drainage, making it a lymphatic boundary. The upper portion above the vocal cords drains to the deep cervical nodes through vessels that penetrate the thyrohyoid membrane. The lower portion below the vocal cords drains to the pre-laryngeal, pre-tracheal, and inferior deep cervical nodes. The aryepiglottic and vestibular folds have a significant lymphatic drainage and are prone to early metastasis.
Anatomy of the Larynx
The larynx is located in the front of the neck, between the third and sixth cervical vertebrae. It is made up of several cartilaginous segments, including the paired arytenoid, corniculate, and cuneiform cartilages, as well as the single thyroid, cricoid, and epiglottic cartilages. The cricoid cartilage forms a complete ring. The laryngeal cavity extends from the laryngeal inlet to the inferior border of the cricoid cartilage and is divided into three parts: the laryngeal vestibule, the laryngeal ventricle, and the infraglottic cavity.
The vocal folds, also known as the true vocal cords, control sound production. They consist of the vocal ligament and the vocalis muscle, which is the most medial part of the thyroarytenoid muscle. The glottis is composed of the vocal folds, processes, and rima glottidis, which is the narrowest potential site within the larynx.
The larynx is also home to several muscles, including the posterior cricoarytenoid, lateral cricoarytenoid, thyroarytenoid, transverse and oblique arytenoids, vocalis, and cricothyroid muscles. These muscles are responsible for various actions, such as abducting or adducting the vocal folds and relaxing or tensing the vocal ligament.
The larynx receives its arterial supply from the laryngeal arteries, which are branches of the superior and inferior thyroid arteries. Venous drainage is via the superior and inferior laryngeal veins. Lymphatic drainage varies depending on the location within the larynx, with the vocal cords having no lymphatic drainage and the supraglottic and subglottic parts draining into different lymph nodes.
Overall, understanding the anatomy of the larynx is important for proper diagnosis and treatment of various conditions affecting this structure.
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This question is part of the following fields:
- Respiratory System
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Question 8
Correct
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An 80-year-old woman presents to the emergency department with a 2-day history of severe abdominal pain, accompanied by nausea and vomiting. Upon examination, she has a distended abdomen that is tender to the touch, and bowel sounds are infrequent. Her medical history includes a hysterectomy and cholecystectomy. A CT scan is ordered, which reveals a bowel obstruction at the L1 level. What is the most likely affected area?
Your Answer: Duodenum
Explanation:The 2nd segment of the duodenum is situated at the transpyloric plane, which corresponds to the level of L1 and is a significant anatomical reference point.
The Transpyloric Plane and its Anatomical Landmarks
The transpyloric plane is an imaginary horizontal line that passes through the body of the first lumbar vertebrae (L1) and the pylorus of the stomach. It is an important anatomical landmark used in clinical practice to locate various organs and structures in the abdomen.
Some of the structures that lie on the transpyloric plane include the left and right kidney hilum (with the left one being at the same level as L1), the fundus of the gallbladder, the neck of the pancreas, the duodenojejunal flexure, the superior mesenteric artery, and the portal vein. The left and right colic flexure, the root of the transverse mesocolon, and the second part of the duodenum also lie on this plane.
In addition, the upper part of the conus medullaris (the tapered end of the spinal cord) and the spleen are also located on the transpyloric plane. Knowing the location of these structures is important for various medical procedures, such as abdominal surgeries and diagnostic imaging.
Overall, the transpyloric plane serves as a useful reference point for clinicians to locate important anatomical structures in the abdomen.
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This question is part of the following fields:
- Respiratory System
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Question 9
Incorrect
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A man in his early fifties comes in with a painful rash caused by herpes on the external auditory meatus. He also has facial palsy on the same side, along with deafness, tinnitus, and vertigo. What is the probable diagnosis?
Your Answer: Bell's palsy
Correct Answer: Ramsay Hunt syndrome
Explanation:Ramsay Hunt syndrome is characterized by a combination of Bell’s palsy facial paralysis, along with symptoms such as a herpetic rash, deafness, tinnitus, and vertigo. It is important to note that the rash may not always be visible, despite being present.
While Bell’s palsy may present with facial paralysis, it does not typically involve the presence of herpetic rashes.
Understanding Ramsay Hunt Syndrome
Ramsay Hunt syndrome, also known as herpes zoster oticus, is a condition that occurs when the varicella zoster virus reactivates in the geniculate ganglion of the seventh cranial nerve. The first symptom of this syndrome is often auricular pain, followed by facial nerve palsy and a vesicular rash around the ear. Other symptoms may include vertigo and tinnitus.
To manage Ramsay Hunt syndrome, doctors typically prescribe oral acyclovir and corticosteroids. These medications can help reduce the severity of symptoms and prevent complications.
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This question is part of the following fields:
- Respiratory System
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Question 10
Incorrect
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A 35-year-old pregnant woman undergoes an ABG test. What is the anticipated outcome for a healthy pregnant woman?
Your Answer: Compensated metabolic acidosis
Correct Answer: Compensated respiratory alkalosis
Explanation:During pregnancy, a woman’s increased tidal volume leads to a decrease in carbon dioxide levels, resulting in alkalosis. This is because carbon dioxide generates acid, and reduced levels of it lead to a decrease in acid. The kidneys eventually adapt to this change by reducing the amount of alkaline bicarbonate in the body. Therefore, pregnancy causes a compensated respiratory alkalosis.
If a woman’s bicarbonate levels remain normal, she would have simple respiratory alkalosis.
On the other hand, if a woman produces excess acid, she would have metabolic acidosis, which is the opposite of what occurs during pregnancy.
Arterial Blood Gas Interpretation: A 5-Step Approach
Arterial blood gas interpretation is a crucial aspect of patient care, particularly in critical care settings. The Resuscitation Council (UK) recommends a 5-step approach to interpreting arterial blood gas results. The first step is to assess the patient’s overall condition. The second step is to determine if the patient is hypoxaemic, with a PaO2 on air of less than 10 kPa. The third step is to assess if the patient is acidaemic (pH <7.35) or alkalaemic (pH >7.45).
The fourth step is to evaluate the respiratory component of the arterial blood gas results. A PaCO2 level greater than 6.0 kPa suggests respiratory acidosis, while a PaCO2 level less than 4.7 kPa suggests respiratory alkalosis. The fifth step is to assess the metabolic component of the arterial blood gas results. A bicarbonate level less than 22 mmol/l or a base excess less than -2mmol/l suggests metabolic acidosis, while a bicarbonate level greater than 26 mmol/l or a base excess greater than +2mmol/l suggests metabolic alkalosis.
To remember the relationship between pH, PaCO2, and bicarbonate, the acronym ROME can be used. Respiratory acidosis or alkalosis is opposite to the pH level, while metabolic acidosis or alkalosis is equal to the pH level. This 5-step approach and the ROME acronym can aid healthcare professionals in interpreting arterial blood gas results accurately and efficiently.
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This question is part of the following fields:
- Respiratory System
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Question 11
Incorrect
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A 23-year-old woman comes to your clinic complaining of difficulty hearing her partner at home. She has been experiencing a high-pitched ringing in her left ear for the past 6 months. She attributes this to attending loud concerts frequently and has not sought medical attention until now. She reports that she can hear better when she is outside but struggles in quiet environments. Upon examination, there are no abnormalities seen during otoscopy. One of the possible diagnoses for this patient is otosclerosis, a condition that primarily affects the stapes bone. Which structure does the stapes bone come into contact with in the cochlea?
Your Answer: Organ of Corti
Correct Answer: Oval window
Explanation:The oval window is where the stapes connects with the cochlea, and it is the most inner of the ossicles. The stapes has a stirrup-like shape, with a head that articulates with the incus and two limbs that connect it to the base. The base of the stapes is in contact with the oval window, which is one of the only two openings between the middle and inner ear. The organ of Corti, which is responsible for hearing, is located on the basilar membrane within the cochlear duct. The round window is the other opening between the middle and inner ear, and it allows the fluid within the cochlea to move, transmitting sound to the hair cells. The helicotrema is the point where the scala tympani and scala vestibuli meet at the apex of the cochlear labyrinth. The tectorial membrane is a membrane that extends along the entire length of the cochlea. A female in her third decade of life with unilateral conductive hearing loss and a family history of hearing loss is likely to have otosclerosis, a condition that affects the stapes and can cause severe or total hearing loss due to abnormal bone growth and fusion with the cochlea.
Anatomy of the Ear
The ear is divided into three distinct regions: the external ear, middle ear, and internal ear. The external ear consists of the auricle and external auditory meatus, which are innervated by the greater auricular nerve and auriculotemporal branch of the trigeminal nerve. The middle ear is the space between the tympanic membrane and cochlea, and is connected to the nasopharynx by the eustachian tube. The tympanic membrane is composed of three layers and is approximately 1 cm in diameter. The middle ear is innervated by the glossopharyngeal nerve. The ossicles, consisting of the malleus, incus, and stapes, transmit sound vibrations from the tympanic membrane to the inner ear. The internal ear contains the cochlea, which houses the organ of corti, the sense organ of hearing. The vestibule accommodates the utricule and saccule, which contain endolymph and are surrounded by perilymph. The semicircular canals, which share a common opening into the vestibule, lie at various angles to the petrous temporal bone.
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This question is part of the following fields:
- Respiratory System
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Question 12
Correct
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A 55-year-old man comes to the hospital complaining of lethargy, headache, and shortness of breath. Upon examination, he is found to be cyanotic and hypoxic, and is admitted to the respiratory ward for oxygen therapy.
Following some initial tests, the consultant informs the patient that his hemoglobin has a high affinity for oxygen, resulting in reduced oxygen delivery to the tissues.
What is the probable reason for this alteration in the oxygen dissociation curve?Your Answer: Low 2,3-DPG
Explanation:The correct answer is low 2,3-DPG. The professor’s description refers to a left shift in the oxygen dissociation curve, which indicates that haemoglobin has a high affinity for oxygen and is less likely to release it to the tissues. Factors that cause a left shift include low temperature, high pH, low PCO2, and low 2,3-DPG. 2,3-DPG is a substance that helps release oxygen from haemoglobin, so low levels of it result in less oxygen being released, causing a left shift in the oxygen dissociation curve.
The answer high temperature is incorrect because it causes a right shift in the oxygen dissociation curve, promoting oxygen delivery to the tissues. Hypercapnoea also causes a right shift in the curve, promoting oxygen delivery. Hyperglycaemia has no effect on haemoglobin’s ability to release oxygen, so it is also incorrect.
Understanding the Oxygen Dissociation Curve
The oxygen dissociation curve is a graphical representation of the relationship between the percentage of saturated haemoglobin and the partial pressure of oxygen in the blood. It is not influenced by the concentration of haemoglobin. The curve can shift to the left or right, indicating changes in oxygen delivery to tissues. When the curve shifts to the left, there is increased saturation of haemoglobin with oxygen, resulting in decreased oxygen delivery to tissues. Conversely, when the curve shifts to the right, there is reduced saturation of haemoglobin with oxygen, leading to enhanced oxygen delivery to tissues.
The L rule is a helpful mnemonic to remember the factors that cause a shift to the left, resulting in lower oxygen delivery. These factors include low levels of hydrogen ions (alkali), low partial pressure of carbon dioxide, low levels of 2,3-diphosphoglycerate, and low temperature. On the other hand, the mnemonic ‘CADET, face Right!’ can be used to remember the factors that cause a shift to the right, leading to raised oxygen delivery. These factors include carbon dioxide, acid, 2,3-diphosphoglycerate, exercise, and temperature.
Understanding the oxygen dissociation curve is crucial in assessing the oxygen-carrying capacity of the blood and the delivery of oxygen to tissues. By knowing the factors that can shift the curve to the left or right, healthcare professionals can make informed decisions in managing patients with respiratory and cardiovascular diseases.
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This question is part of the following fields:
- Respiratory System
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Question 13
Correct
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A 75-year-old man is having a left pneumonectomy for bronchial carcinoma. When the surgeons reach the root of the lung, which structure will be the most anterior in the anatomical plane?
Your Answer: Phrenic nerve
Explanation:The lung root contains two nerves, with the phrenic nerve positioned in the most anterior location and the vagus nerve situated in the most posterior location.
Anatomy of the Lungs
The lungs are a pair of organs located in the chest cavity that play a vital role in respiration. The right lung is composed of three lobes, while the left lung has two lobes. The apex of both lungs is approximately 4 cm superior to the sternocostal joint of the first rib. The base of the lungs is in contact with the diaphragm, while the costal surface corresponds to the cavity of the chest. The mediastinal surface contacts the mediastinal pleura and has the cardiac impression. The hilum is a triangular depression above and behind the concavity, where the structures that form the root of the lung enter and leave the viscus. The right main bronchus is shorter, wider, and more vertical than the left main bronchus. The inferior borders of both lungs are at the 6th rib in the mid clavicular line, 8th rib in the mid axillary line, and 10th rib posteriorly. The pleura runs two ribs lower than the corresponding lung level. The bronchopulmonary segments of the lungs are divided into ten segments, each with a specific function.
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This question is part of the following fields:
- Respiratory System
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Question 14
Correct
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A 59-year-old man comes to see his GP complaining of vertigo that has been going on for three days. He also reports experiencing left-sided ear pain and a change in his sense of taste, as well as constant ringing in his left ear. He took paracetamol on his own, but the vertigo persisted, so he decided to seek medical attention.
During the examination, the doctor observes that the man has a drooping left face with involvement of the forehead. Upon otoscopic examination, vesicles are seen in the external auditory canal of the left ear. A neurological examination is performed, which is normal except for the left facial paralysis.
What is the appropriate treatment for this man's condition?Your Answer: Oral acyclovir and corticosteroids
Explanation:Ramsay Hunt syndrome is treated with a combination of oral acyclovir and corticosteroids. This condition is caused by the varicella zoster virus, as evidenced by the presence of vesicles on the left ear and involvement of the seventh and eighth cranial nerves. Symptoms include facial paralysis and hearing impairments. Treatment typically involves a seven to ten day course of oral acyclovir and a five day course of corticosteroids, such as prednisolone.
It is important to note that oseltamivir (tamiflu) is an antiviral used for influenzae, while chloroquine is typically used for malaria. Amoxicillin is an antibiotic and is not effective in treating viral infections. While corticosteroids can provide relief from inflammation, they are not the primary treatment for Ramsay Hunt syndrome when used alone.
Understanding Ramsay Hunt Syndrome
Ramsay Hunt syndrome, also known as herpes zoster oticus, is a condition that occurs when the varicella zoster virus reactivates in the geniculate ganglion of the seventh cranial nerve. The first symptom of this syndrome is often auricular pain, followed by facial nerve palsy and a vesicular rash around the ear. Other symptoms may include vertigo and tinnitus.
To manage Ramsay Hunt syndrome, doctors typically prescribe oral acyclovir and corticosteroids. These medications can help reduce the severity of symptoms and prevent complications.
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This question is part of the following fields:
- Respiratory System
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Question 15
Incorrect
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What is the carrier rate of cystic fibrosis in the United Kingdom?
Your Answer: 1 in 100
Correct Answer: 1 in 25
Explanation:Understanding Cystic Fibrosis
Cystic fibrosis is a genetic disorder that causes thickened secretions in the lungs and pancreas. It is an autosomal recessive condition that occurs due to a defect in the cystic fibrosis transmembrane conductance regulator gene (CFTR), which regulates a chloride channel. In the UK, 80% of CF cases are caused by delta F508 on chromosome 7, and the carrier rate is approximately 1 in 25.
CF patients are at risk of colonization by certain organisms, including Staphylococcus aureus, Pseudomonas aeruginosa, Burkholderia cepacia (previously known as Pseudomonas cepacia), and Aspergillus. These organisms can cause infections and exacerbate symptoms in CF patients. It is important for healthcare providers to monitor and manage these infections to prevent further complications.
Overall, understanding cystic fibrosis and its associated risks can help healthcare providers provide better care for patients with this condition.
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This question is part of the following fields:
- Respiratory System
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Question 16
Incorrect
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Mrs. Johnson is an 82-year-old woman who visited her General practitioner complaining of gradual worsening shortness of breath over the past two months. During the medical history, it was discovered that she has had Chronic Obstructive Pulmonary Disease (COPD) for 20 years.
Upon examination, there are no breath sounds at both lung bases and a stony dull note to percussion over the same areas. Based on this clinical scenario, what is the probable cause of her recent exacerbation of shortness of breath?Your Answer: Pulmonary oedema secondary to heart failure
Correct Answer: Pleural transudate effusion secondary to cor pulmonale
Explanation:The most likely cause of a pleural transudate is heart failure. This is due to the congestion of blood into the systemic venous circulation, which can result from long-standing COPD and increase in pulmonary vascular resistance leading to right-sided heart failure or cor pulmonale. Other options such as infective exacerbation of COPD or pulmonary edema secondary to heart failure are less likely to explain the clinical signs. Pleural exudate effusion secondary to cor pulmonale is also not the most appropriate answer as it would cause a transudate pleural effusion, not an exudate.
Understanding the Causes and Features of Pleural Effusion
Pleural effusion is a medical condition characterized by the accumulation of fluid in the pleural space, which is the area between the lungs and the chest wall. The causes of pleural effusion can be classified into two types: transudate and exudate. Transudate is characterized by a protein concentration of less than 30g/L and is commonly caused by heart failure, hypoalbuminemia, liver disease, and other conditions. On the other hand, exudate is characterized by a protein concentration of more than 30g/L and is commonly caused by infections, pneumonia, tuberculosis, and other conditions.
The symptoms of pleural effusion may include dyspnea, non-productive cough, and chest pain. Upon examination, patients may exhibit dullness to percussion, reduced breath sounds, and reduced chest expansion. It is important to identify the underlying cause of pleural effusion to determine the appropriate treatment plan. Early diagnosis and treatment can help prevent complications and improve the patient’s overall health.
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This question is part of the following fields:
- Respiratory System
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Question 17
Incorrect
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A 35-year-old man comes to the clinic complaining of worsening retrosternal chest pain that radiates to the neck and shoulders and is pleuritic in nature. During examination, a pericardial friction rub is heard at the end of expiration. The diagnosis is pericarditis. What nerve supplies this area?
Your Answer: Long thoracic nerve
Correct Answer: Phrenic nerve
Explanation:The correct answer is the phrenic nerve, which provides sensory innervation to the pericardium, the central part of the diaphragm, and the mediastinal part of the parietal pleura. It also supplies motor function to the diaphragm. The long thoracic nerve, medial pectoral nerve, thoracodorsal nerve, and vagus nerve are all incorrect answers.
The Phrenic Nerve: Origin, Path, and Supplies
The phrenic nerve is a crucial nerve that originates from the cervical spinal nerves C3, C4, and C5. It supplies the diaphragm and provides sensation to the central diaphragm and pericardium. The nerve passes with the internal jugular vein across scalenus anterior and deep to the prevertebral fascia of the deep cervical fascia.
The right phrenic nerve runs anterior to the first part of the subclavian artery in the superior mediastinum and laterally to the superior vena cava. In the middle mediastinum, it is located to the right of the pericardium and passes over the right atrium to exit the diaphragm at T8. On the other hand, the left phrenic nerve passes lateral to the left subclavian artery, aortic arch, and left ventricle. It passes anterior to the root of the lung and pierces the diaphragm alone.
Understanding the origin, path, and supplies of the phrenic nerve is essential in diagnosing and treating conditions that affect the diaphragm and pericardium.
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This question is part of the following fields:
- Respiratory System
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Question 18
Correct
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A 70-year-old man visits his primary care physician with complaints of hearing difficulties. He states that he has been increasingly struggling to hear his wife's conversations for the past six months. He is concerned that this problem will worsen and eventually lead to complete hearing loss, making it difficult for him to communicate with his children over the phone. His wife is also distressed by the situation, as he frequently asks her to turn up the volume on the television. The man has no history of exposure to loud noises and has well-controlled hypertension. He is a retired police officer and currently resides with his wife. What is the primary pathology underlying this man's most likely diagnosis?
Your Answer: Degeneration of the cells at the cochlear base
Explanation:The patient has a gradual-onset hearing loss, which is most likely due to presbycusis, an aging-related sensorineural hearing loss. This condition has multiple causes, including environmental factors like noise pollution and biological factors like genetics and oxidative stress. Damage to the organ of Corti stereocilia from exposure to sudden loud noises can also cause hearing loss, which is typically sudden and associated with a history of exposure to loud noises. Other conditions that can cause hearing loss include cholesteatoma, which is due to the accumulation of keratin debris in the middle ear, and otosclerosis, which is characterized by the overgrowth of bone in the middle ear.
Anatomy of the Ear
The ear is divided into three distinct regions: the external ear, middle ear, and internal ear. The external ear consists of the auricle and external auditory meatus, which are innervated by the greater auricular nerve and auriculotemporal branch of the trigeminal nerve. The middle ear is the space between the tympanic membrane and cochlea, and is connected to the nasopharynx by the eustachian tube. The tympanic membrane is composed of three layers and is approximately 1 cm in diameter. The middle ear is innervated by the glossopharyngeal nerve. The ossicles, consisting of the malleus, incus, and stapes, transmit sound vibrations from the tympanic membrane to the inner ear. The internal ear contains the cochlea, which houses the organ of corti, the sense organ of hearing. The vestibule accommodates the utricule and saccule, which contain endolymph and are surrounded by perilymph. The semicircular canals, which share a common opening into the vestibule, lie at various angles to the petrous temporal bone.
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This question is part of the following fields:
- Respiratory System
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Question 19
Correct
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A 50-year-old woman with a recent diagnosis of COPD is admitted to the hospital for treatment of an exacerbation caused by infection. She reports smoking 10 cigarettes per day and has a family history of lung cancer. Her chest x-ray shows signs of emphysema, and she mentions that her parents and siblings also have the disease. She asks for advice on the best course of action to improve her prognosis.
Your Answer: Stop smoking
Explanation:The most crucial step to enhance the patient’s prognosis is to assist them in quitting smoking. While lung reduction surgery and long-term oxygen therapy may benefit certain patient groups, smoking cessation remains the top priority. Proper inhaler technique and adherence, as well as the use of home nebulizers, can provide symptomatic relief for the patient.
The National Institute for Health and Care Excellence (NICE) updated its guidelines on the management of chronic obstructive pulmonary disease (COPD) in 2018. The guidelines recommend general management strategies such as smoking cessation advice, annual influenzae vaccination, and one-off pneumococcal vaccination. Pulmonary rehabilitation is also recommended for patients who view themselves as functionally disabled by COPD.
Bronchodilator therapy is the first-line treatment for patients who remain breathless or have exacerbations despite using short-acting bronchodilators. The next step is determined by whether the patient has asthmatic features or features suggesting steroid responsiveness. NICE suggests several criteria to determine this, including a previous diagnosis of asthma or atopy, a higher blood eosinophil count, substantial variation in FEV1 over time, and substantial diurnal variation in peak expiratory flow.
If the patient does not have asthmatic features or features suggesting steroid responsiveness, a long-acting beta2-agonist (LABA) and long-acting muscarinic antagonist (LAMA) should be added. If the patient is already taking a short-acting muscarinic antagonist (SAMA), it should be discontinued and switched to a short-acting beta2-agonist (SABA). If the patient has asthmatic features or features suggesting steroid responsiveness, a LABA and inhaled corticosteroid (ICS) should be added. If the patient remains breathless or has exacerbations, triple therapy (LAMA + LABA + ICS) should be offered.
NICE only recommends theophylline after trials of short and long-acting bronchodilators or to people who cannot use inhaled therapy. Azithromycin prophylaxis is recommended in select patients who have optimised standard treatments and continue to have exacerbations. Mucolytics should be considered in patients with a chronic productive cough and continued if symptoms improve.
Cor pulmonale features include peripheral oedema, raised jugular venous pressure, systolic parasternal heave, and loud P2. Loop diuretics should be used for oedema, and long-term oxygen therapy should be considered. Smoking cessation, long-term oxygen therapy in eligible patients, and lung volume reduction surgery in selected patients may improve survival in patients with stable COPD. NICE does not recommend the use of ACE-inhibitors, calcium channel blockers, or alpha blockers
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This question is part of the following fields:
- Respiratory System
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Question 20
Correct
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A 35-year-old man is stabbed in the right chest and requires a thoracotomy. During the procedure, the right lung is mobilized and the pleural reflection at the lung hilum is opened. Which of the following structures is not located in this area?
Your Answer: Azygos vein
Explanation:The pulmonary ligament extends from the pleural reflections surrounding the hilum of the lung and covers the pulmonary vessels and bronchus. However, it does not contain the azygos vein.
Anatomy of the Lungs
The lungs are a pair of organs located in the chest cavity that play a vital role in respiration. The right lung is composed of three lobes, while the left lung has two lobes. The apex of both lungs is approximately 4 cm superior to the sternocostal joint of the first rib. The base of the lungs is in contact with the diaphragm, while the costal surface corresponds to the cavity of the chest. The mediastinal surface contacts the mediastinal pleura and has the cardiac impression. The hilum is a triangular depression above and behind the concavity, where the structures that form the root of the lung enter and leave the viscus. The right main bronchus is shorter, wider, and more vertical than the left main bronchus. The inferior borders of both lungs are at the 6th rib in the mid clavicular line, 8th rib in the mid axillary line, and 10th rib posteriorly. The pleura runs two ribs lower than the corresponding lung level. The bronchopulmonary segments of the lungs are divided into ten segments, each with a specific function.
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This question is part of the following fields:
- Respiratory System
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