Critical Care Medicine

Critical Care Medicine Indian Medical PG Question 1: The best measure of organ perfusion and the best monitor of adequacy of shock therapy is

• A. urine output (Correct Answer)
• B. restoring blood pressure/pulse vital parameters
• C. central venous pressure
• D. pulmonary wedge pressure

Critical Care Medicine Explanation: ***urine output*** - **Urine output** is a direct and sensitive indicator of **renal blood flow** and, consequently, overall organ perfusion [1]. Adequate urine production (typically >0.5 mL/kg/hr) signifies that the kidneys are being sufficiently perfused, which generally correlates with adequate perfusion of other vital organs. - In the context of shock, improved urine output following therapy indicates effective restoration of **circulating blood volume** and microcirculation, making it an excellent monitor for treatment adequacy. *restoring blood pressure/pulse vital parameters* - While restoring **blood pressure** and **pulse** is a critical goal in shock management, these parameters alone do not always reflect true tissue perfusion [1]. A patient can have normalized blood pressure due to **vasoconstriction** while still experiencing inadequate microcirculatory flow and cellular hypoxia. - These vital signs are systemic indicators, and while essential, they don't provide the same granular insight into **organ-level perfusion** as urine output. *central venous pressure* - **Central venous pressure (CVP)** primarily reflects the **right heart's filling pressure** and overall intravascular volume status [1]. While CVP helps guide fluid resuscitation, it is not a direct measure of organ perfusion. - CVP can be influenced by various factors, including **cardiac function** and **intrathoracic pressure**, and a "normal" CVP does not guarantee adequate perfusion to all organs [1]. *pulmonary wedge pressure* - **Pulmonary wedge pressure (PWP)**, also known as pulmonary artery occlusion pressure, reflects the **left atrial pressure** and serves as an indicator of left ventricular preload [1]. - While PWP is useful in assessing **cardiac function** and guiding fluid management in specific types of shock [1] (e.g., cardiogenic shock), it is not a primary measure of global organ perfusion or a universal monitor for adequacy of shock therapy.

Critical Care Medicine Indian Medical PG Question 2: A patient who met with an accident presented to the emergency department, he lost 25% of his total blood volume approximately, blood pressure is normal. He/she will be classified under which class of hypovolemic shock?

• A. Class II (Correct Answer)
• B. Class I
• C. Class III
• D. Class IV

Critical Care Medicine Explanation: ***Class II*** - A 25% blood loss (within the **15-30% range**), with **blood pressure remaining normal**, categorizes this patient into **Class II hypovolemic shock**. - In Class II, compensatory mechanisms such as increased **heart rate** and **peripheral vasoconstriction** maintain systolic blood pressure despite significant volume loss. - Patients typically present with **tachycardia (100-120 bpm)**, **narrowed pulse pressure**, mild **anxiety**, and **normal systolic BP**. *Class I* - Class I shock involves **minimal blood loss** (up to 15%), with blood loss <750 mL in adults. - Patients in Class I typically present with **normal vital signs** and minimal to no clinical symptoms. - The 25% blood loss exceeds the threshold for Class I classification. *Class III* - Class III shock is characterized by blood loss of **30-40%** (1500-2000 mL in adults). - This level of loss typically results in **decreased systolic blood pressure**, **marked tachycardia (120-140 bpm)**, **confusion**, and clinical instability. - The patient's normal blood pressure and 25% loss are **below the threshold** for Class III shock. *Class IV* - Class IV shock involves massive blood loss of **greater than 40%** (>2000 mL in adults). - Presents with profound **hypotension**, **severe tachycardia (>140 bpm)**, **altered consciousness**, and **imminent cardiovascular collapse**. - This patient's normal blood pressure and stable condition are inconsistent with Class IV shock.

Critical Care Medicine Indian Medical PG Question 3: All of the following are indicators of adequacy of pre-operative resuscitation except

• A. Hematocrit level
• B. Consciousness level
• C. C-reactive protein level (Correct Answer)
• D. Urine output

Critical Care Medicine Explanation: ***C-reactive protein level*** - **C-reactive protein (CRP)** is an inflammatory marker and is not a direct indicator of the adequacy of pre-operative fluid and hemodynamic resuscitation. An elevated CRP suggests ongoing inflammation or infection, not necessarily a deficit in perfusion or hydration. - While inflammation can coincide with critical illness requiring resuscitation, CRP itself does not provide real-time information about **organ perfusion**, **oxygen delivery**, or **fluid status**. *Hematocrit level* - **Hematocrit** levels are crucial for assessing factors like **blood loss** and **hemoconcentration**, which directly impact the need for and adequacy of resuscitation. An increasing hematocrit can indicate hemoconcentration, while a decreasing hematocrit may suggest blood loss. - It helps guide decisions regarding **blood product transfusions** and overall fluid management. *Consciousness level* - The **level of consciousness** is a vital clinical indicator of **cerebral perfusion** and overall brain oxygenation. Deterioration can signal inadequate resuscitation and poor cerebral blood flow. - Improvements in consciousness level after interventions suggest improved **systemic perfusion** and oxygen delivery to the brain. *Urine output* - **Urine output** is a sensitive and widely used indicator of **renal perfusion** and overall systemic hydration status. Adequate urine output (e.g., >0.5 mL/kg/hr) suggests sufficient renal blood flow. - Low or absent urine output can indicate **hypovolemia**, **poor cardiac output**, or **renal hypoperfusion**, highlighting the need for further resuscitation.

Critical Care Medicine Indian Medical PG Question 4: Which of the following parameters is most critical for maintaining optimal oxygenation?

• A. FiO2
• B. Respiratory rate
• C. PEEP (Correct Answer)
• D. Tidal volume

Critical Care Medicine Explanation: ***PEEP*** - **Positive End-Expiratory Pressure (PEEP)** is crucial for maintaining optimal oxygenation because it prevents **alveolar collapse** at the end of expiration, thereby increasing the **functional residual capacity** and improving gas exchange. - By keeping alveoli open, PEEP increases the number of available alveoli for ventilation, preventing **atelectasis** and optimizing the **venous admixture** from non-ventilated lung units. *FiO2* - While **Fraction of Inspired Oxygen (FiO2)** is essential for providing sufficient oxygen, simply increasing FiO2 without proper alveolar recruitment and patency (often achieved with PEEP) can be less effective and potentially harmful due to **oxygen toxicity**. - High FiO2 can improve oxygenation in cases of **hypoxemia**, but it doesn't address underlying problems like **alveolar collapse** or **ventilation-perfusion mismatch** as directly as PEEP does. *Respiratory rate* - **Respiratory rate** primarily affects **carbon dioxide elimination** (PaCO2) and, to some extent, alveolar ventilation. - While an adequate respiratory rate is necessary for overall gas exchange, it is not the most direct or critical parameter for optimizing **oxygenation** compared to PEEP's role in maintaining alveolar patency. *Tidal volume* - **Tidal volume** also primarily affects **carbon dioxide elimination** and plays a role in overall minute ventilation. - Excessive tidal volume can lead to **ventilator-induced lung injury (VILI)**, while insufficient tidal volume can reduce minute ventilation, but it does not directly optimize oxygenation by preventing **alveolar collapse** in the same way PEEP does.

Critical Care Medicine Indian Medical PG Question 5: The following ventilation modality is used in:

• A. Meconium aspiration syndrome
• B. Assessment of extubation potential (Correct Answer)
• C. Bronchiolitis obliterans organizing pneumonia
• D. Acute exacerbation of chronic bronchitis

Critical Care Medicine Explanation: ***Assessment of extubation potential*** - The image depicts **Continuous Positive Airway Pressure (CPAP)**, as indicated by the "Applied CPAP level" and the continuous positive pressure throughout the respiratory cycle, with slight variations but no distinct inspiratory aid. - CPAP is commonly used as a **weaning modality** to assess a patient's ability to breathe spontaneously and maintain adequate oxygenation and ventilation before extubation. *Meconium aspiration syndrome* - Meconium aspiration syndrome often causes severe respiratory distress, requiring **high-frequency oscillatory ventilation (HFOV)** or **conventional mechanical ventilation** with high PEEP and ventilation strategies to minimize barotrauma and air trapping. - While CPAP might be used in milder cases or during the weaning phase, it is not the primary or defining ventilation modality for initial management of severe MAS. *Bronchiolitis obliterans organizing pneumonia* - **Bronchiolitis obliterans organizing pneumonia (BOOP)**, now known as cryptogenic organizing pneumonia, is a restrictive lung disease that typically responds to **corticosteroids**. - Ventilatory support, if needed, would generally involve conventional mechanical ventilation, not specifically CPAP in its primary management. *Acute exacerbation of chronic bronchitis* - **Acute exacerbations of chronic bronchitis (AECB)**, particularly those leading to hypercapnic respiratory failure, are commonly treated with **non-invasive positive pressure ventilation (NIPPV)**, such as BiPAP, which provides both inspiratory (IPAP) and expiratory (EPAP) pressure support. - While CPAP can be used in some cases, BiPAP is generally preferred for its ability to reduce the work of breathing and improve ventilation in hypercapnic patients.

Critical Care Medicine Indian Medical PG Question 6: Patient in hospital was given IVF and patient develops hyperchloremic metabolic acidosis. Which fluid will cause this?

• A. RL
• B. 5 % dextrose
• C. NS (Correct Answer)
• D. DNS

Critical Care Medicine Explanation: ***NS*** - **Normal Saline (0.9% NaCl)** contains a **chloride concentration of 154 mEq/L**, which is unphysiologically high (supranormal) compared to plasma (approx. 100 mEq/L). - Rapid infusion leads to the retention of excess chloride and dilution of serum bicarbonate, resulting in a **non-anion gap (hyperchloremic) metabolic acidosis**. *RL* - Ringer's Lactate (RL) is a **buffered solution** because it contains **lactate (28 mEq/L)**, which is metabolized by the liver into bicarbonate. - Because of the bicarbonate precursor (lactate) and a near-physiologic chloride concentration (109 mEq/L), RL tends to **prevent or correct** acidosis, rather than causing it. *DNS* - Dextrose Normal Saline (DNS) still contains the **supranormal chloride concentration** (154 mEq/L) from the normal saline component, posing a similar theoretical risk. - However, it is typically less associated with severe acidosis than pure NS in large volumes, and often the primary differentiating fluid in this context is the **buffered RL**. *5 % dextrose* - **5% Dextrose in Water (D5W)** contains no electrolytes (salt) and is only used to provide free water and small amounts of calories. - Rapid infusion of D5W results in dilution and can cause **hyponatremia** and free water excess, but it cannot precipitate hyperchloremic acidosis.

Critical Care Medicine Indian Medical PG Question 7: Which is not an obvious advantage of high-flow nasal cannula (HFNC):

• A. Bypassing nasopharyngeal dead space
• B. Hot and Humidification of air (Correct Answer)
• C. PEEP
• D. Decreases need for intubation

Critical Care Medicine Explanation: *Hot and Humidification of air* - This is an **obvious advantage** of HFNC, as it delivers warmed and humidified oxygen directly, improving patient comfort and mucociliary clearance. - The constant flow ensures the upper airway mucosa remains hydrated, preventing dryness and irritation that can occur with conventional oxygen therapy. ***Bypassing nasopharyngeal dead space*** - While HFNC does replace the gas in the **nasopharynx** with fresh gas, reducing dead space, this benefit is related to the high flow rate and is considered an **obvious advantage** in improving ventilatory efficiency. - The continuous washout of CO2 from the upper airway directly contributes to improved gas exchange. *PEEP* - HFNC can generate a modest level of **positive end-expiratory pressure (PEEP)**, which is an intentional and recognized effect due to the high flow rates. - This PEEP helps to recruit collapsed alveoli and improve oxygenation, making it an **obvious advantage** in respiratory support. *Decreases need for intubation* - The ability of HFNC to improve oxygenation, reduce work of breathing, and minimize airways inflammation is a well-established and **obvious advantage** that often prevents the need for invasive mechanical ventilation. - Clinical studies consistently demonstrate that HFNC can reduce intubation rates in patients with acute respiratory failure.

Critical Care Medicine Indian Medical PG Question 8: Which of the following is most cardio depressant

• A. Sevoflurane
• B. Halothane (Correct Answer)
• C. Isoflurane
• D. Desflurane

Critical Care Medicine Explanation: ***Halothane*** - **Halothane** is known for causing significant **myocardial depression** by directly reducing myocardial contractility and stroke volume. - It also **sensitizes the myocardium to catecholamines**, increasing the risk of arrhythmias. *Sevoflurane* - **Sevoflurane** causes less **myocardial depression** and is often preferred in patients with compromised cardiac function. - Its effects on heart rate and blood pressure are generally moderate compared to halothane. *Isoflurane* - **Isoflurane** can cause **systemic vasodilation** and a dose-dependent decrease in blood pressure but is generally less cardio-depressant than halothane. - It maintains **cardiac output** better than halothane, sometimes increasing heart rate to compensate for vasodilation. *Desflurane* - **Desflurane** typically causes a **lesser degree of myocardial depression** and tends to preserve cardiac output. - It can, however, lead to transient increases in heart rate and blood pressure upon rapid increases in concentration due to **sympathetic stimulation**.

Critical Care Medicine Indian Medical PG Question 9: Which of the following conditions are contraindications for noninvasive positive-pressure ventilation in patients with respiratory failure? I. Craniofacial abnormalities II. Significant burns III. Respiratory failure with PaCO_2 of 60 mm Hg IV. Cardiovascular instability Select the correct answer using the code given below :

• A. I, III and IV
• B. II, III and IV
• C. I, II and IV (Correct Answer)
• D. I, II and III

Critical Care Medicine Explanation: ***I, II and IV*** - **Craniofacial abnormalities** (I) can prevent a proper mask seal, leading to air leaks and ineffective ventilation. - **Significant burns** (II), especially on the face, can make mask application impossible due to pain, skin integrity issues, and infection risk. - **Cardiovascular instability** (IV), such as severe hypotension or active myocardial ischemia, can be worsened by the positive intrathoracic pressure applied by NPPV, which can decrease venous return and cardiac output. *I, III and IV* - While **craniofacial abnormalities** (I) and **cardiovascular instability** (IV) are contraindications, NPPV can be beneficial for **respiratory failure with a PaCO2 of 60 mm Hg** (III) as it helps reduce CO2 levels and avoids intubation. - Therefore, including III as a contraindication makes this option incorrect. *II, III and IV* - **Significant burns** (II) and **cardiovascular instability** (IV) are clear contraindications. However, **respiratory failure with a PaCO2 of 60 mm Hg** (III) is often an indication for NPPV, not a contraindication. - This option incorrectly identifies a key indication as a contraindication. *I, II and III* - **Craniofacial abnormalities** (I) and **significant burns** (II) are valid contraindications for NPPV. - However, **respiratory failure with a PaCO2 of 60 mm Hg** (III) is a common indication for NPPV, especially in conditions like COPD exacerbations, as it helps improve ventilation and reduce hypercapnia.

Critical Care Medicine Indian Medical PG Question 10: All of the following are used to maintain proper oxygen flow to the patient except:

• A. Different pin index for nitrogen and oxygen (Correct Answer)
• B. A proportioner between N₂ and O₂ control valves
• C. Calibrated oxygen concentration analyzers
• D. Placement of oxygen flowmeter downstream of the nitrogen flowmeter

Critical Care Medicine Explanation: ***Different pin index for nitrogen and oxygen*** - Oxygen and nitrogen *do not* use pin index safety systems; the **Pin Index Safety System (PISS)** is used for small gas cylinders to prevent wrong gas connection, but nitrogen is a non-medical gas. - While medical gases have specific pin index patterns, this system is for preventing inadvertent connection of gas cylinders to the wrong yoke, not for *maintaining proper oxygen flow to the patient* from the anesthesia machine's internal system. *A proportioner between N₂ and O₂ control valves* - This device, such as the **Ohio proportioner** or **Link 25 system**, mechanically or pneumatically links the **nitrous oxide (N₂O)** and **oxygen (O₂)** flow controls. - It ensures that the inspired oxygen concentration never falls below a preset safe level, typically 25%, thereby **preventing hypoxic gas mixtures**. *Calibrated oxygen concentration analyzers* - **Oxygen analyzers** continuously monitor the inspired oxygen concentration and provide an audible and visual alarm if the level deviates from the set range. - This serves as a critical safety measure to detect and alert anesthesia providers to **hypoxic gas delivery** or machine malfunctions. *Placement of oxygen flowmeter downstream of the nitrogen flowmeter* - Positioning the **oxygen flowmeter downstream** (closest to the patient) of all other gas flowmeters (e.g., nitrous oxide, air) is a crucial safety feature. - This design ensures that **any leak occurring upstream** of the oxygen flow tube will primarily affect other gases, reducing the risk of an **undetected hypoxic mixture** reaching the patient.

Critical Care Medicine Flashcard 1 of 9

Question: The ideal rate of chest compressions in CPR is _____/min

Answer: 100-120

Critical Care Medicine Flashcard 2 of 9

Question: 2020 AHA guidelines recommendations:Parameters such as _____ may be used to monitor and optimize CPR quality

Answer: ETCO2

Critical Care Medicine Flashcard 3 of 9

Question: Patients who suffer unexpected cardiac arrest during intensive care are classified under Category _____ of Modified Maastricht classification

Answer: V

Critical Care Medicine Flashcard 4 of 9

Question: If after CPR initiation, PETCO2 is improve CPR quality

Answer: If after CPR initiation, PETCO2 is improve CPR quality

Critical Care Medicine Flashcard 5 of 9

Question: Therapeutic Hypothermia may be used in management of _____ in infants and _____ in adults

Answer: HIE; Cardiac arrest

Critical Care Medicine Flashcard 6 of 9

Question: If after CPR initiation, relaxation phase (diastolic) pressure is improve CPR quality

Answer: If after CPR initiation, relaxation phase (diastolic) pressure is improve CPR quality

Critical Care Medicine Flashcard 7 of 9

Question: Following second defib and CPR cycle, next step is to give patient IV _____ every 3-5 mins

Answer: epinephrine

Critical Care Medicine Flashcard 8 of 9

Question: In a cardiac arrest patient, if an intravenous access cannot be made, _____ is the next best way to administer epinephrine

Answer: intraosseus

Critical Care Medicine Flashcard 9 of 9

Question: Patients who suffer unexpected cardiac arrest during or after the determination of brain death are classified under Category _____ of Modified Maastricht classification

Answer: IV