Fitness for Altitude and Diving — MCQs
In an accident case, after the arrival of medical team, all should be done in early management except;
Which of the following is not done in high altitude sickness?
Which physiological adaptation does not happen at high altitudes?
Which is a feature of high-altitude pulmonary edema?
Which of the following is seen in high altitude climbers?
At what altitude is kala azar unlikely to occur?
Which of the following is correct about the flow volume curve shown below? (Recent NEET Pattern 2016-17)
How does pulmonary hypertension contribute to hemoptysis?
Which flow volume curve recording is shown below?
Which of the following areas of nitrogen washout test indicate closing volume?
Fitness for Altitude and Diving Indian Medical PG Practice Questions and MCQs
Question 1: In an accident case, after the arrival of medical team, all should be done in early management except;
- A. Glasgow coma scale
- B. Check BP (Correct Answer)
- C. Stabilization of cervical vertebrae
- D. Check Respiration
Explanation: ***Check BP*** - In the **immediate/early management** of trauma (primary survey), while circulation assessment is crucial, the **initial assessment of circulation** focuses on: - **Pulse rate and quality** (radial, carotid) - **Capillary refill time** - **Skin color and temperature** - **Active hemorrhage control** - **Formal blood pressure measurement** with a cuff, while important, is typically recorded during or after these rapid initial assessments, as it takes more time to obtain an accurate reading. - In the context of this question, among the four options listed, BP measurement is relatively less immediate compared to the other life-saving priorities (airway protection, breathing assessment, C-spine stabilization, and GCS). - **Note:** This is a nuanced distinction - BP is assessed during primary survey, but the other three options have more immediate life-threatening implications if not addressed. *Glasgow coma scale* - **GCS assessment** is part of the **"D" (Disability)** step in the ATLS primary survey. - It is performed early to assess neurological status and level of consciousness. - GCS <8 indicates need for **definitive airway protection** (intubation). - This is a critical early assessment that guides immediate management decisions. *Stabilization of cervical vertebrae* - **C-spine immobilization** is part of the **"A" (Airway)** step - "Airway with cervical spine protection." - It is performed **simultaneously** with airway assessment using a **rigid cervical collar**. - This is the **first priority** in trauma management to prevent secondary spinal cord injury. - All trauma patients should be assumed to have C-spine injury until proven otherwise. *Check Respiration* - **Respiratory assessment** is part of the **"B" (Breathing)** step in the ATLS primary survey. - This involves checking: - **Respiratory rate and pattern** - **Chest wall movement** - **Air entry bilaterally** - **Signs of tension pneumothorax or flail chest** - This is an immediate life-saving priority and must be assessed early.
Question 2: Which of the following is not done in high altitude sickness?
- A. Rapid descent
- B. Acetazolamide
- C. Oxygen
- D. Digoxin (Correct Answer)
Explanation: ***Digoxin*** - **Digoxin** is a cardiac glycoside used for heart conditions like **atrial fibrillation** and **heart failure**. It has no role in the treatment of high altitude sickness. - Its primary actions are to increase **myocardial contractility** and decrease heart rate, which are not beneficial in addressing the hypobaric hypoxia of high altitude. *Rapid descent* - **Rapid descent** is the most effective and often immediate treatment for severe forms of high altitude sickness, such as **High Altitude Cerebral Edema (HACE)** or **High Altitude Pulmonary Edema (HAPE)** [2]. - It involves moving the affected individual to a significantly lower altitude to alleviate the effects of **hypoxia** [2]. *Acetazolamide* - **Acetazolamide** is a **carbonic anhydrase inhibitor** commonly used for the prevention and treatment of high altitude sickness [2]. - It works by inducing a **metabolic acidosis**, which stimulates **respiration** and increases **oxygenation**. *Oxygen* - Administering **supplemental oxygen** is a crucial treatment for high altitude sickness, especially in more severe cases [2]. - It directly counteracts the **hypoxia** experienced at high altitudes, improving symptoms and preventing progression [1], [2].
Question 3: Which physiological adaptation does not happen at high altitudes?
- A. Pulmonary vasoconstriction
- B. Respiratory acidosis (Correct Answer)
- C. Hypoxia
- D. Polycythemia
Explanation: ***Respiratory acidosis*** - At high altitudes, the primary physiological response to **hypoxia** is to increase ventilation, leading to a decrease in **arterial PCO2**. - This reduction in **PCO2** causes **respiratory alkalosis**, not acidosis, as the body tries to compensate for the lower oxygen levels. *Pulmonary vasoconstriction* - This is a significant physiological response to **hypoxia** at high altitudes, leading to an increase in **pulmonary artery pressure**. - Its purpose is to divert blood flow to better-ventilated areas of the lung, but it can also contribute to **pulmonary hypertension**. *Hypoxia* - Reduced **atmospheric pressure** at high altitudes directly results in a lower partial pressure of oxygen (**PO2**), leading to **hypoxia**. - This low **PO2** is the primary trigger for most other physiological adaptations seen at high altitudes. *Polycythemia* - Prolonged exposure to **hypoxia** stimulates the kidneys to release **erythropoietin (EPO)**, which in turn increases **red blood cell production**. - This adaptive increase in **red blood cell count** and **hemoglobin concentration** aims to enhance the oxygen-carrying capacity of the blood.
Question 4: Which is a feature of high-altitude pulmonary edema?
- A. Associated with low cardiac output
- B. Exercise has no effect
- C. Associated with pulmonary hypertension (Correct Answer)
- D. Occurs in both acclimatized and unacclimatized persons
Explanation: ***Associated with pulmonary hypertension*** - **High-altitude pulmonary edema (HAPE)** is characterized by **exaggerated hypoxic pulmonary vasoconstriction**, leading to significantly increased pulmonary artery pressures. - This **pulmonary hypertension** drives fluid extravasation into the alveolar spaces, causing non-cardiogenic pulmonary edema. *Associated with low cardiac output* - HAPE is typically associated with **normal or elevated cardiac output** in response to hypoxia, not low cardiac output. - Low cardiac output suggests conditions like cardiogenic shock or severe myocardial dysfunction, which are not primary features of HAPE. *Exercise has no effect* - **Physical exertion at altitude** is a significant risk factor and can worsen HAPE due to increased cardiac output and pulmonary blood flow, exacerbating pulmonary hypertension. - Rest and reduced activity are crucial components of preventing and treating HAPE, indicating that exercise does indeed have an effect. *Occurs in both acclimatized and unacclimatized persons* - HAPE primarily affects **unacclimatized individuals** or those who ascend rapidly to high altitudes. - While rare, it can occur in previously acclimatized individuals returning to altitude after a period at lower elevations or in those with predisposing factors, but it is predominantly a disease of the unacclimatized.
Question 5: Which of the following is seen in high altitude climbers?
- A. Hyperventilation
- B. Pulmonary edema
- C. Decreased PaCO2
- D. All of the options (Correct Answer)
Explanation: ***All of the options*** - High altitude climbers experience **hypoxia**, which triggers several physiological responses as the body tries to compensate. - **Hyperventilation**, **pulmonary edema**, and **decreased PaCO2** are all common occurrences in individuals exposed to high altitudes. *Hyperventilation* - **Hypoxia** at high altitudes stimulates the peripheral chemoreceptors, leading to an increased respiratory rate and depth. - This increased ventilation is a compensatory mechanism to try and increase **oxygen intake**. *Pulmonary edema* - **High-altitude pulmonary edema (HAPE)** is a potentially life-threatening condition caused by exaggerated hypoxic pulmonary vasoconstriction. - This leads to increased pulmonary arterial pressure, capillary leakage, and **fluid accumulation in the lungs**. *Decreased PaCO2* - The increased respiratory rate due to **hyperventilation** causes an excessive exhalation of carbon dioxide. - This results in a **decreased partial pressure of arterial carbon dioxide (PaCO2)**, leading to respiratory alkalosis.
Question 6: At what altitude is kala azar unlikely to occur?
- A. 400 meters
- B. 500 meters
- C. 600 meters (Correct Answer)
- D. 200 meters
Explanation: ***600 meters*** - Kala-azar, or **visceral leishmaniasis**, is primarily found in **low-lying areas** and is rarely reported at altitudes above 600 meters due to the specific ecological requirements of its **sand fly vector**. - The **Phlebotomus argentipes sand fly**, the main vector in the Indian subcontinent, prefers warm, humid climates and **lower altitudes**. *400 meters* - This altitude is within the **typical endemic range** for kala-azar, especially in regions like the Indian subcontinent. - The environmental conditions at 400 meters are generally conducive for the **survival and breeding** of the sand fly vector. *500 meters* - Similar to 400 meters, 500 meters is still considered within the **favorable altitude range** for kala-azar transmission. - The **sand fly vector** can thrive in the climate often found at this elevation. *200 meters* - This altitude represents a **highly endemic zone** for kala-azar, as it provides optimal conditions for the sand fly vector. - Lower altitudes are typically associated with increased **humidity and warmth**, favoring vector density and parasite transmission.
Question 7: Which of the following is correct about the flow volume curve shown below? (Recent NEET Pattern 2016-17)
- A. A= Emphysema, B= Upper airway obstruction, C= Pulmonary fibrosis
- B. A= Extraparenchymal restrictive lung disease, B= upper airway obstruction, C= Pulmonary fibrosis
- C. A= Emphysema, B= Extraparenchymal restrictive lung disease, C= Pulmonary fibrosis
- D. A= Emphysema, B= Upper airway obstruction, C= Extraparenchymal restrictive lung disease (Correct Answer)
Explanation: ***Correct Answer: A= Emphysema, B= Upper airway obstruction, C= Extraparenchymal restrictive lung disease*** - Curve **A** shows a reduced expiratory flow rate, especially in later expiration, and an increased residual volume, consistent with **emphysema** due to loss of elastic recoil. - Curve **B** shows a plateauing of both inspiratory and expiratory limbs, characteristic of a **fixed upper airway obstruction**. - Curve **C** shows a shift to the left with reduced lung volumes but preserved or increased flow rates, typical of **extraparenchymal restrictive lung disease**. *Incorrect: A= Emphysema, B= Upper airway obstruction, C= Pulmonary fibrosis* - While A and B are correctly identified, C is incorrectly identified as pulmonary fibrosis. **Pulmonary fibrosis** is an *intraparenchymal* restrictive lung disease, which would show a proportionate reduction in both flow and volume, similar to C but typically with less preserved flow rates at lower volumes. - Extraparenchymal restrictive lung disease (like chest wall restriction or neuromuscular disease) reduces lung volumes but the airways themselves are usually healthy, leading to strong expiratory efforts for the reduced volume. *Incorrect: A= Extraparenchymal restrictive lung disease, B= upper airway obstruction, C= Pulmonary fibrosis* - Curve **A** is clearly indicative of an obstructive pattern with a significantly prolonged and reduced expiratory flow, not extraparenchymal restrictive disease. - Curve **C** is restrictive, but the specific pattern aligns better with extraparenchymal restrictive disease rather than pulmonary fibrosis (an intraparenchymal restrictive disease). *Incorrect: A= Emphysema, B= Extraparenchymal restrictive lung disease, C= Pulmonary fibrosis* - Curve **B** shows a characteristic **fixed obstruction pattern** (plateauing), which is seen in upper airway obstruction, not extraparenchymal restrictive lung disease. - Curve **C** is restrictive, but as noted, the pattern here is more consistent with extraparenchymal restriction than pulmonary fibrosis.
Question 8: How does pulmonary hypertension contribute to hemoptysis?
- A. Increased alveolar pressure
- B. Increased bronchial artery pressure (Correct Answer)
- C. Elevated pulmonary venous pressure
- D. Vasoconstriction of pulmonary arteries
Explanation: ***Increased bronchial artery pressure*** - In chronic **pulmonary hypertension**, bronchial arteries undergo **hypertrophy and develop extensive collateral circulation** to compensate for reduced pulmonary blood flow. - These hypertrophied bronchial arteries are **high-pressure systemic vessels** (unlike the low-pressure pulmonary circulation) and can form **bronchopulmonary anastomoses**. - **Rupture of these dilated, thin-walled bronchial vessels** is the primary mechanism of hemoptysis in pulmonary hypertension, particularly massive hemoptysis. - This is commonly seen in conditions like **chronic pulmonary thromboembolism, Eisenmenger syndrome**, and other causes of chronic pulmonary hypertension. *Elevated pulmonary venous pressure* - **Elevated pulmonary venous pressure** causes hemoptysis in **left heart failure and mitral stenosis**, not in primary pulmonary arterial hypertension. - Pulmonary arterial hypertension is a **pre-capillary condition** affecting arteries; pulmonary venous pressure is typically normal or low. - This option confuses pulmonary arterial hypertension with pulmonary venous hypertension (post-capillary), which are distinct pathophysiologic entities. *Increased alveolar pressure* - Increased alveolar pressure (e.g., from **mechanical ventilation with high PEEP**) causes **barotrauma** leading to pneumothorax or pneumomediastinum. - This is **unrelated to pulmonary hypertension** and does not cause hemoptysis through the vascular mechanisms seen in pulmonary hypertension. *Vasoconstriction of pulmonary arteries* - **Vasoconstriction is a key feature** of pulmonary arterial hypertension pathophysiology, contributing to elevated pulmonary artery pressure. - However, vasoconstriction itself does not directly cause vessel rupture; rather, it is the **chronic high pressure leading to bronchial artery collateralization** that results in hemoptysis. - The thick-walled pulmonary arteries are less prone to rupture compared to thin-walled bronchial collaterals.
Question 9: Which flow volume curve recording is shown below?
- A. Parenchymal obstructive airway disease
- B. Fixed intrathoracic obstruction (Correct Answer)
- C. Variable extrathoracic obstruction
- D. Variable intrathoracic obstruction
Explanation: ***Fixed intrathoracic obstruction*** - The flow-volume loop shows **flattening of both inspiratory and expiratory limbs** equally. This indicates a fixed obstruction within the intrathoracic airways, affecting airflow during both phases regardless of transmural pressure changes. - Examples include **tracheal stenosis** or **tumors** within the main bronchi, which permanently narrow the airway. *Parenchymal obstructive airway disease* - This condition (e.g., asthma, COPD) would typically show a **decreased peak expiratory flow** and a "scooped out" appearance of the expiratory limb, while the inspiratory limb is often preserved or only mildly affected. - The obstruction is primarily within the **smaller airways** and can vary with lung volume. *Variable extrathoracic obstruction* - This would result in a flattened inspiratory limb but a relatively normal expiratory limb because the **negative inspiratory pressure collapses the airway lumen** during inspiration, while positive expiratory pressure often helps to open it. - Examples include vocal cord dysfunction or goiter compressing the trachea **outside the chest cavity**. *Variable intrathoracic obstruction* - This would primarily affect the **expiratory limb**, causing flattening, as the positive intrathoracic pressure during exhalation tends to narrow the already compromised airway. The inspiratory limb would be less affected. - Conditions like **tracheomalacia** within the chest cavity can cause this, where the airway collapses during exhalation.
Question 10: Which of the following areas of nitrogen washout test indicate closing volume?
- A. 1
- B. 2
- C. 3
- D. 4 (Correct Answer)
Explanation: ***4*** - Area 4 represents the **closing volume**. This is the point where the **small airways in the dependent parts of the lungs close**, leading to a sharp increase in the nitrogen concentration in the exhaled gas. - This sharp increase occurs because air from the upper regions of the lungs, which are better ventilated, continues to empty, and this air has a higher concentration of nitrogen as the patient was initially breathing 100% oxygen. *1* - Area 1 is known as the **anatomical dead space**, representing the initial part of exhalation consisting entirely of gas from the conducting airways (which has a near-zero nitrogen concentration). - This phase reflects the emptying of gas that did not participate in gas exchange, thus showing very low nitrogen levels as it's primarily the 100% oxygen inhaled for the test. *2* - Area 2, or the **alveolar washout phase**, shows a rapid increase in nitrogen concentration as exhaled gas now includes a mixture of dead space air and alveolar air. - This phase reflects the emptying of alveoli from different regions of the lung, but not yet the effect of airway closure. *3* - Area 3 is the **alveolar plateau**, where the nitrogen concentration remains relatively stable, indicating uniform emptying from the remaining open alveoli. - This plateau phase shows the mixing of gases from various lung units, with a steady increase in nitrogen as the oxygen washes out.
Want unlimited practice?
Get full access to all questions, explanations, and performance tracking.
Start For Free