Invasive Hemodynamic Monitoring — MCQs
ABPI increases artificially in
All are the Complication of CVP line except
The 'a' wave in jugular venous pressure is due to?
Most sensitive method of monitoring cardiovascular ischemia in the perioperative period is -
In which vein is Central Venous Pressure (CVP) most accurately monitored?
Decreased CVP is seen in
Which among the following is the best method to assess adequacy of fluid resuscitation in a polytrauma patient:
Swan Ganz catheter is used for what ?
A patient presents with cold skin, fatigue, shortness of breath on exertion, and an enlarged liver. Upon examination, his jugular venous pressure (JVP) reveals a prominent "a" wave. What is the most likely cause of the elevated "a" wave in this patient?
Early and reliable indication of air embolism during anaesthesia can be obtained by continuous monitoring of:
Invasive Hemodynamic Monitoring Indian Medical PG Practice Questions and MCQs
Question 1: ABPI increases artificially in
- A. Ischemic limb ulcers
- B. Intermittent claudication syndrome
- C. Deep vein thrombosis (DVT)
- D. Conditions causing arterial calcification (Correct Answer)
Explanation: ***Conditions causing arterial calcification*** - In cases of **arterial calcification**, particularly in conditions like **diabetes** and **chronic kidney disease**, the blood vessels become stiff and non-compressible. - This stiffness leads to falsely elevated ankle systolic pressures because the cuff cannot effectively compress the calcified arteries, resulting in an artificially high **Ankle-Brachial Pressure Index (ABPI)** reading [2]. *Ischemic limb ulcers* - **Ischemic limb ulcers** are a direct consequence of **peripheral artery disease (PAD)**, which is characterized by reduced blood flow to the extremities [2]. - In these conditions, the ABPI would be **decreased** (typically < 0.9), indicating impaired blood supply, not an increase [2]. *Intermittent claudication syndrome* - **Intermittent claudication** is a classic symptom of **peripheral artery disease (PAD)**, where pain occurs in the legs during exercise due to insufficient blood flow [1]. - This syndrome is associated with a **reduced ABPI**, as arterial narrowing limits oxygen delivery to the muscles during exertion [1]. *Deep vein thrombosis (DVT)* - **Deep vein thrombosis (DVT)** is a condition involving a blood clot in a deep vein, typically in the legs. - DVT does not directly cause an artificial increase in ABPI; it primarily affects venous return and can cause swelling and pain, but not elevated arterial pressure readings [2].
Question 2: All are the Complication of CVP line except
- A. Haemothorax
- B. Airway injury (Correct Answer)
- C. Air embolism
- D. Septicemia
Explanation: ***Airway injury*** - While central venous catheterization can cause various complications, direct **airway injury** (e.g., tracheal puncture) is extremely rare and not a typical complication of the procedure itself as the insertion sites are generally not near the major airways. - Complications usually involve vascular, pleural, or infectious issues rather than direct damage to the respiratory tree. *Haemothorax* - **Haemothorax** can occur if the subclavian or internal jugular vein is punctured and the needle or catheter inadvertently punctures an adjacent artery (e.g., subclavian artery), leading to bleeding into the pleural space. - This complication presents with respiratory distress and signs of hypovolemia as blood accumulates in the thoracic cavity. *Air embolism* - **Air embolism** is a serious complication, especially during insertion or removal of a CVP line, if the catheter lumen is exposed to air and negative intrathoracic pressure sucks air into the venous system. - It can lead to sudden cardiorespiratory collapse and is a recognized risk of CVP placement. *Septicemia* - **Septicemia** (or central line-associated bloodstream infection, CLABSI) is a common and serious complication, particularly with prolonged catheter dwelling times, poor aseptic technique, or inadequate site care. - Bacteria can colonize the catheter surface and enter the bloodstream, leading to systemic infection.
Question 3: The 'a' wave in jugular venous pressure is due to?
- A. Atrial filling
- B. Atrial relaxation
- C. Atrial contraction (Correct Answer)
- D. Ventricular relaxation
Explanation: ***Atrial contraction*** - The **a wave** in jugular venous pressure (JVP) corresponds to the increase in right atrial pressure due to **atrial systole** (contraction). - This pushes blood against the closed tricuspid valve and back into the great veins, causing a visible pulsation. *Atrial filling* - **Atrial filling** occurs during diastole and contributes to the overall increase in atrial pressure but is not the primary cause of the a wave. - This phase is more related to the **v wave** (due to ventricular contraction pushing blood into the atria against a closed tricuspid valve) and the **y descent** (due to tricuspid valve opening and rapid ventricular filling). *Atrial relaxation* - **Atrial relaxation** follows **atrial contraction** and is associated with the **x descent** on the JVP waveform, representing the decrease in right atrial pressure as the atrium relaxes and the tricuspid valve moves away from the atrium during ventricular systole. - It results in a fall in pressure not a rise, so it cannot be the a wave. *Ventricular relaxation* - **Ventricular relaxation** (early diastole) is primarily responsible for the **y descent**, which occurs as the tricuspid valve opens and blood rapidly empties from the atrium into the ventricle. - This phase of the cardiac cycle is related to falling pressures within the right atrium and ventricle, not the initial pressure rise seen in the **a wave**.
Question 4: Most sensitive method of monitoring cardiovascular ischemia in the perioperative period is -
- A. NIBP
- B. ECG
- C. Pulse oximeter
- D. TEE (Correct Answer)
Explanation: ***TEE*** - **Transesophageal echocardiography (TEE)** is the most sensitive method for detecting perioperative myocardial ischemia because it can visualize **regional wall motion abnormalities** and changes in **ventricular function** much earlier than ECG. - **Ischemia** directly impairs the contractility of the affected myocardium, leading to subtle changes in wall motion that TEE can identify. *NIBP* - **Non-invasive blood pressure (NIBP)** monitoring can detect **hemodynamic changes** (like hypotension or hypertension) that may precede or accompany ischemia. - However, these changes are **non-specific** and occur relatively late, making NIBP a less sensitive indicator of early ischemia. *ECG* - **Electrocardiography (ECG)** monitors the electrical activity of the heart and can detect **ST-segment changes** indicative of ischemia. - While useful, ECG changes may appear later than wall motion abnormalities, and **silent ischemia** can be missed if the leads are not optimally placed or if the ischemia does not produce significant electrical changes. *Pulse oximeter* - A **pulse oximeter** measures **oxygen saturation** in the peripheral blood. - It is primarily used to assess **respiratory function** and tissue oxygenation, and it does not directly monitor myocardial ischemia or cardiac function.
Question 5: In which vein is Central Venous Pressure (CVP) most accurately monitored?
- A. Anterior jugular vein
- B. External jugular vein
- C. Inferior vena cava
- D. Internal jugular vein (Correct Answer)
Explanation: ***Internal jugular vein*** - The **internal jugular vein** provides the **most direct and consistent access** to the superior vena cava and right atrium, where CVP is accurately measured. - Its straight course and reliable anatomical landmarks make it a preferred site for CVP catheter insertion. *Anterior jugular vein* - The **anterior jugular vein** is smaller and often has a more tortuous course, making consistent and reliable CVP monitoring difficult. - It is not typically chosen for central venous access due to its anatomical variability and smaller caliber. *External jugular vein* - The **external jugular vein** is superficially located and easier to access but often has valves and a more oblique angle to the subclavian vein, making catheter advancement to the central circulation challenging. - Catheter tip placement is less consistent for accurate CVP measurements compared to the internal jugular vein. *Inferior vena cava* - While the **inferior vena cava** eventually drains into the right atrium, access is typically via the femoral vein, which is associated with a higher risk of infection and deep vein thrombosis for long-term CVP monitoring. - Measurements from the inferior vena cava or femoral vein can be affected by **intra-abdominal pressure** and are not as accurately reflective of right atrial pressure as those from the superior vena cava.
Question 6: Decreased CVP is seen in
- A. PEEP
- B. Bacterial sepsis (Correct Answer)
- C. Heart failure
- D. Pneumothorax
Explanation: ***Bacterial sepsis*** - In **sepsis**, widespread **vasodilation** and increased capillary permeability lead to significant fluid redistribution out of the intravascular space [3]. - This results in a decrease in **venous return** and thus a lower **central venous pressure (CVP)** due to relative hypovolemia [2]. *Pneumothorax* - A **pneumothorax** causes increased intrathoracic pressure, compressing the great veins and heart. - This leads to **reduced venous return** and typically an *increase* in CVP, or at least a minimal change, due to obstructed outflow from the right atrium, not a decrease [2]. *PEEP* - **Positive end-expiratory pressure (PEEP)** increases intrathoracic pressure, which impedes venous return to the right atrium [2]. - This elevated pressure can artificially *increase* the measured CVP reading, and it does not typically cause a decrease in intrinsic CVP [2]. *Heart failure* - In **heart failure**, particularly right-sided heart failure or biventricular failure, the heart's pumping efficiency is reduced [1]. - This leads to **venous congestion** and an *increase* in CVP due to fluid overload and the inability of the right ventricle to effectively pump blood forward [2].
Question 7: Which among the following is the best method to assess adequacy of fluid resuscitation in a polytrauma patient:
- A. CVP
- B. Pulse rate
- C. Urine output (Correct Answer)
- D. BP
Explanation: ***Urine output*** - **Urine output** is a direct and real-time reflection of **renal perfusion**, which is highly sensitive to changes in circulating blood volume and cardiac output in trauma patients. - Maintaining a urine output of **0.5-1 mL/kg/hr** is generally accepted as a key indicator of adequate fluid resuscitation and organ perfusion in polytrauma. *CVP* - **Central Venous Pressure (CVP)** can be influenced by multiple factors beyond fluid status, such as **intrathoracic pressure**, **venous tone**, and **right ventricular function**, making it an unreliable sole indicator. - While it offers some insight into preload, CVP measurements alone do not provide a direct and dynamic assessment of **end-organ perfusion** in trauma. *Pulse rate* - **Pulse rate** is a non-specific indicator that can be affected by pain, anxiety, medications, and other systemic responses beyond fluid status in polytrauma. - While **tachycardia** often suggests hypovolemia, a normal pulse rate does not guarantee adequate fluid resuscitation, especially in patients with compensatory mechanisms. *BP* - **Blood pressure (BP)** is a relatively late indicator of hypovolemia in trauma, as compensatory mechanisms can maintain BP near normal despite significant blood loss. - Relying solely on BP can lead to delayed recognition of **inadequate resuscitation** and potential end-organ damage.
Question 8: Swan Ganz catheter is used for what ?
- A. saturation in mixed venous blood
- B. Pulmonary capillary pressure (Correct Answer)
- C. LV filling pressure
- D. Pulmonary artery occlusion pressure
Explanation: ***Pulmonary capillary pressure*** - A Swan-Ganz catheter, when properly wedged, measures the **pulmonary capillary wedge pressure (PCWP)**, which is an indirect estimate of the left atrial pressure [1] and, consequently, the **left ventricular end-diastolic pressure (LVEDP)** or **preload**. - This measurement helps in assessing left heart function and fluid status [1]. *saturation in mixed venous blood* - While a Swan-Ganz catheter can measure **mixed venous oxygen saturation (SvO2)** from the distal port positioned in the pulmonary artery, this is not its primary or most unique diagnostic application. - SvO2 reflects the balance between oxygen delivery and consumption, providing insights into overall tissue perfusion and oxygen utilization. *LV filling pressure* - The Swan-Ganz catheter does not directly measure the **left ventricular (LV) filling pressure**. Instead, it estimates it indirectly via the **pulmonary capillary wedge pressure (PCWP)**, which is typically a good surrogate for LVEDP [1]. - Direct measurement of LV filling pressure would require a catheter to be placed within the left ventricle. *Pulmonary artery occlusion pressure* - **Pulmonary artery occlusion pressure (PAOP)** is the technical term for the pressure measured when the balloon at the tip of the Swan-Ganz catheter is inflated, occluding a branch of the pulmonary artery [1]. This pressure is synonymous with the **pulmonary capillary wedge pressure (PCWP)**. - Therefore, while the Swan-Ganz catheter measures PAOP, PCWP is a more common and direct description of the physiological parameter being assessed, which represents the pulmonary capillary pressure.
Question 9: A patient presents with cold skin, fatigue, shortness of breath on exertion, and an enlarged liver. Upon examination, his jugular venous pressure (JVP) reveals a prominent "a" wave. What is the most likely cause of the elevated "a" wave in this patient?
- A. Tricuspid Stenosis (Correct Answer)
- B. Mitral Stenosis
- C. Tricuspid Regurgitation
- D. Mitral Regurgitation
- E. Pulmonary Stenosis
Explanation: ***Tricuspid Stenosis*** - A prominent "a" wave in the **JVP** indicates increased **right atrial pressure** during atrial contraction, which is characteristic of **tricuspid stenosis** due to resistance to blood flow from the right atrium to the right ventricle. - The symptoms of **cold skin**, **fatigue**, **shortness of breath on exertion**, and an **enlarged liver** are consistent with **right-sided heart failure** caused by tricuspid stenosis. - Among the valvular causes, tricuspid stenosis most directly causes a prominent "a" wave with associated right heart failure symptoms. *Mitral Stenosis* - **Mitral stenosis** primarily affects the **left atrium** and left ventricle, leading to pulmonary symptoms and, if severe, right heart failure. - It would typically cause a prominent "a" wave in the **pulmonary veins**, not directly in the JVP, although severe pulmonary hypertension could eventually lead to right ventricular overload. *Tricuspid Regurgitation* - **Tricuspid regurgitation** causes a large, prominent, and often **pulsatile "c-v" wave** in the JVP due to the reflux of blood into the right atrium during ventricular systole. - While it can cause right heart failure symptoms, it does not typically present with an isolated prominent "a" wave. *Mitral Regurgitation* - **Mitral regurgitation** primarily affects the **left side of the heart**, leading to symptoms related to left heart failure (e.g., pulmonary edema). - It does not directly cause an elevated "a" wave in the **JVP** unless there is severe, longstanding left-sided heart failure leading to secondary pulmonary hypertension and right heart failure. *Pulmonary Stenosis* - **Pulmonary stenosis** causes obstruction to right ventricular outflow, which can lead to a prominent "a" wave due to increased right atrial pressure. - However, pulmonary stenosis typically presents with a **systolic ejection murmur** at the left upper sternal border and may have signs of **RV hypertrophy** rather than the predominantly congestive symptoms seen here. - The clinical picture of hepatomegaly and signs of backward failure is more consistent with tricuspid stenosis than pulmonary stenosis.
Question 10: Early and reliable indication of air embolism during anaesthesia can be obtained by continuous monitoring of:
- A. Oxygen saturation
- B. End Tidal CO2 (Correct Answer)
- C. ECG
- D. Blood pressure
Explanation: ***End Tidal CO2*** - A sudden and unexplained decrease in **End Tidal CO2 (EtCO2)** is often the first sign of an air embolism. - This occurs because air in the pulmonary circulation obstructs blood flow, leading to reduced CO2 delivery to the lungs. *Oxygen saturation* - **Oxygen saturation** changes are typically a later sign of air embolism, as significant pulmonary impairment or right-to-left shunting must occur before a drop is detectable. - A decrease in saturation indicates a more advanced and potentially severe embolism. *ECG* - **ECG changes**, such as arrhythmias or signs of right heart strain, are usually late and non-specific indicators of air embolism. - These changes reflect the cardiovascular consequences of the embolism rather than its initial event. *Blood pressure* - A drop in **blood pressure** is a late and often profound sign of an air embolism, reflecting significant cardiovascular compromise. - Early detection methods precede observable changes in systemic blood pressure.
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