Difficult Airway Algorithms — MCQs

10 questions

Laryngeal mask airway [LMA] is contraindicated in?

Patient with BMI 40 presents for emergency surgery. All are correct about airway management EXCEPT:

Which of these is the most life-threatening injury that can be identified by assessing the breathing component of the patient?

All of the following are related to difficult intubation, except which of the following?

What is to be addressed first in case of polytrauma -

An unconscious child is brought to the casualty. What is the correct sequence of the management?

Maximum Airway Irritation caused by:-

A 45-year-old patient develops bronchospasm during induction. Which inhalational agent is most suitable for management?

A construction worker met with an accident when a cement block fell on his face. He sustained severe maxillofacial and laryngeal injury. He was not able to open his mouth and is having jaw fracture with obstruction in nasopharynx and oropharynx. To stabilize his airway, the following procedure was done on him. Which option describes the procedure done on him?

Q10

Recommended illumination range for regular work is _______ foot-candles.

Difficult Airway Algorithms Indian Medical PG Practice Questions and MCQs

Question 1: Laryngeal mask airway [LMA] is contraindicated in?

A. Ocular surgeries
B. Pregnant female (Correct Answer)
C. Difficult airways
D. In CPR

Explanation: ***Pregnant female*** - **Pregnant patients** are at an increased risk of **gastric reflux and aspiration pneumonitis** due to decreased lower esophageal sphincter tone and increased intra-abdominal pressure. - The LMA does not provide a secure airway seal against aspiration, making it contraindicated in cases where **aspiration risk is high**, such as pregnancy or full stomach. *Difficult airways* - The LMA is often considered a **rescue device** in difficult airway algorithms when tracheal intubation fails. - It can be used as a conduit for **fiberoptic intubation** or as a temporary airway while preparing for a definitive airway. *Ocular surgeries* - LMAs are generally suitable for ocular surgeries as they provide a stable airway without the use of a mask, which can obstruct the surgical field. - They tend to cause **less coughing and straining** upon insertion and maintenance compared to endotracheal tubes, which is beneficial in preventing increases in intraocular pressure. *In CPR* - The LMA can be an effective airway device during **cardiopulmonary resuscitation (CPR)** when endotracheal intubation is not immediately feasible. - It provides a relatively quick and easy way to establish an airway, facilitate ventilation, and reduce the risk of gastric insufflation during chest compressions.

Question 2: Patient with BMI 40 presents for emergency surgery. All are correct about airway management EXCEPT:

A. Extended ramping
B. Avoid cricoid pressure (Correct Answer)
C. Rapid sequence induction
D. Avoid preoxygenation

Explanation: ***Avoid cricoid pressure*** - While **cricoid pressure** (Sellick's maneuver) is used to prevent **aspiration** by compressing the esophagus, its effectiveness in **obese patients** is highly debated and often hindered by excess neck tissue. - In obese patients, cricoid pressure can actually worsen the view during laryngoscopy, making intubation more difficult and potentially causing airway trauma. *Extended ramping* - **Ramping** the patient, where the head and shoulders are elevated, is crucial in **obese patients** to align the **oral, pharyngeal, and laryngeal axes**. - This position improves the view during laryngoscopy and facilitates successful intubation by effectively displacing excess tissue. *Rapid sequence induction* - **Rapid sequence induction (RSI)** is often indicated in **obese patients** undergoing emergency surgery due to their increased risk of **gastric reflux** and **pulmonary aspiration**. - RSI involves administering a sedative and a paralytic agent in rapid succession, followed immediately by intubation, to minimize the time the airway is unprotected. *Avoid preoxygenation* - **Preoxygenation** is essential in **obese patients** to maximize their **oxygen reserves** before intubation. - Obese patients have reduced **functional residual capacity (FRC)** and increased **oxygen consumption**, making them desaturate rapidly during apnea, so preoxygenation significantly prolongs safe apnea time.

Question 3: Which of these is the most life-threatening injury that can be identified by assessing the breathing component of the patient?

A. Blunt cardiac injury
B. Tension pneumothorax (Correct Answer)
C. Cervical spine injury
D. Laryngotracheal injury

Explanation: ***Tension pneumothorax*** - A tension pneumothorax is a **life-threatening condition** identified during the breathing assessment, as it severely impairs ventilation and causes **hemodynamic instability** by compressing major vessels. - Key signs include absent breath sounds on the affected side, **tracheal deviation**, and **hypotension** due to mediastinal shift. *Blunt cardiac injury* - While serious, blunt cardiac injury is typically identified during the **circulation assessment**, with signs like arrhythmias, hypotension, or cardiac tamponade. - Its direct impact on breathing is less immediate compared to a tension pneumothorax. *Cervical spine injury* - A cervical spine injury can affect breathing if it involves the **phrenic nerve** (C3-C5), leading to respiratory paralysis, but this is assessed during the **disability component** or secondary survey for neurological deficits. - It does not directly cause an acute, life-threatening compromise of lung function discernible primarily through a breathing assessment like a tension pneumothorax. *Laryngotracheal injury* - A laryngotracheal injury primarily affects the **airway component** (A in ABCDE), leading to immediate obstruction or stridor. - While critical, it is distinct from problems with the lungs' ability to expand or perform gas exchange, which are assessed under breathing.

Question 4: All of the following are related to difficult intubation, except which of the following?

A. TMJ ankylosis
B. Micrognathia
C. Increased thyromental distance (Correct Answer)
D. Miller's sign

Explanation: ***Increased thyromental distance*** - An **increased thyromental distance** (greater than 6.5 cm) indicates more space between the mental protuberance and the thyroid cartilage, suggesting better laryngeal visualization and thus a **lower likelihood of difficult intubation**. - This measurement correlates with the adequacy of the submandibular space, which is crucial for achieving an optimal sniffing position for intubation. *Miller's sign* - **Miller's sign** refers to a prominent or anterior larynx, which can make it challenging to visualize the glottis during direct laryngoscopy. - This anatomical feature can obstruct the view of the vocal cords, thereby increasing the difficulty of intubation. *TMJ ankylosis* - **Temporomandibular joint (TMJ) ankylosis** significantly restricts mouth opening, which is essential for laryngoscope insertion and laryngeal visualization. - Limited mouth opening is a well-established predictor of **difficult intubation** because it prevents adequate alignment of the oral, pharyngeal, and laryngeal axes. *Micrognathia* - **Micrognathia**, or a small mandible, is associated with a posterior displacement of the tongue and a reduction in the space available for laryngoscope insertion. - This anatomical variation makes it difficult to achieve an adequate view of the glottis and can lead to **difficult or failed intubation**.

Question 5: What is to be addressed first in case of polytrauma -

A. Circulation
B. Neurology
C. Blood Pressure
D. Airway (Correct Answer)

Explanation: ***Airway*** - Maintaining a **patent airway** is the absolute first priority in polytrauma management according to the **ATLS (Advanced Trauma Life Support)** protocol. - Failure to secure an airway can lead to **hypoxia** and **brain damage** within minutes, regardless of other injuries. *Circulation* - While critical, addressing **circulation** (C in ABCDE) comes after establishing a secure airway and adequate breathing (A and B). - Uncontrolled hemorrhage would be the focus of circulation management, but only after guaranteeing proper oxygenation. *Neurology* - Neurological assessment (D in ABCDE for Disability) follows the primary survey of airway, breathing, and circulation. - Initial neurological evaluation focuses on **level of consciousness** using the **GCS (Glasgow Coma Scale)**. *Blood Pressure* - **Blood pressure** is an indicator of circulatory status but is not the first thing to be addressed. - It falls under the "C" for circulation in the ATLS protocol, which is secondary to airway and breathing.

Question 6: An unconscious child is brought to the casualty. What is the correct sequence of the management?

A. Circulation, Airway, Breathing
B. Breathing, Circulation, Airway
C. Circulation, Breathing, Airway
D. Airway, Breathing, Circulation (Correct Answer)

Explanation: ***Airway, Breathing, Circulation*** - The **ABC sequence** is the cornerstone of pediatric resuscitation as per **PALS (Pediatric Advanced Life Support) guidelines** - In an unconscious child, a patent **airway** is the absolute first priority - without this, no oxygen can reach the lungs regardless of breathing effort - Once airway patency is ensured, **breathing** must be assessed and supported to provide adequate ventilation and oxygenation - Only after securing airway and breathing should **circulation** be addressed, as effective circulation without oxygenation is futile - This sequence prevents **hypoxic brain injury**, which can occur within 4-6 minutes of oxygen deprivation *Circulation, Airway, Breathing* - This violates the fundamental **ABC principle** of emergency management - Prioritizing **circulation** before establishing a patent **airway** means attempting to circulate deoxygenated blood - Without airway patency, any circulatory support will fail to deliver oxygen to vital organs, leading to **irreversible hypoxic damage** - In pediatric emergencies, respiratory failure is more common than primary cardiac arrest, making airway management even more critical *Breathing, Circulation, Airway* - Attempting to support **breathing** before securing the **airway** is physiologically ineffective - An obstructed airway prevents air entry despite breathing efforts or bag-mask ventilation attempts - This sequence can lead to **gastric distension, aspiration**, and worsening hypoxia - Delays in airway management increase the risk of **cardiac arrest** from prolonged hypoxemia *Circulation, Breathing, Airway* - This sequence dangerously delays **airway management**, the most time-critical intervention - In an unconscious child, airway obstruction from tongue falling back or secretions is common and immediately life-threatening - Without a patent airway, neither breathing support nor circulatory measures can prevent **brain death** from anoxia - Following this sequence contradicts all **international resuscitation guidelines** (PALS, AHA, ERC)

Question 7: Maximum Airway Irritation caused by:-

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

Explanation: ***Desflurane*** - **Desflurane** has a pungent odor and is known to cause significant **airway irritation**, leading to coughing, breath-holding, laryngospasm, and secretions, especially during induction. - Its high volatility and low blood-gas solubility contribute to its rapid onset and offset, but also increase its propensity for airway irritation. *Halothane* - **Halothane** has a sweet, non-pungent odor and is generally well-tolerated during induction, causing minimal airway irritation. - Although it causes myocardial depression and is associated with hepatotoxicity, airway irritation is not a primary concern. *Enflurane* - **Enflurane** has a mild, sweet odor and causes less airway irritation than **desflurane**, but more than halothane or sevoflurane. - It can cause central nervous system excitation at high concentrations, but airway irritation is not its most prominent side effect. *Sevoflurane* - **Sevoflurane** has a pleasant, non-pungent odor and is known for its minimal airway irritation, making it an excellent choice for inhalational inductions, particularly in pediatric patients. - It is often preferred over other volatile anesthetics when airway reactivity is a concern. *Isoflurane* - **Isoflurane** has a pungent odor and can cause moderate airway irritation, but generally less than desflurane. - It is associated with a higher incidence of coughing and breath-holding during induction compared to sevoflurane.

Question 8: A 45-year-old patient develops bronchospasm during induction. Which inhalational agent is most suitable for management?

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

Explanation: ***Sevoflurane*** - **Sevoflurane** is an excellent choice for managing intraoperative **bronchospasm** due to its low airway irritancy and potent **bronchodilating** properties. - Its rapid onset and offset allow for quick adjustment of anesthetic depth to help relieve airway constriction. *Halothane* - While **halothane** has significant **bronchodilating effects**, its use is limited due to concerns about **hepatotoxicity** (halothane hepatitis) and cardiac arrhythmias. - It is rarely used in modern anesthetic practice, especially when safer alternatives like sevoflurane are available. *Isoflurane* - **Isoflurane** is a **bronchodilator**, but it tends to be more **pungent** and airway irritant than sevoflurane, potentially exacerbating bronchospasm upon induction or during light anesthesia. - It has a slower onset and offset compared to sevoflurane, making it less ideal for rapid resolution of an acute bronchospasm. *Desflurane* - **Desflurane** is a known **airway irritant** and can precipitate or worsen **bronchospasm**, particularly in patients with reactive airway disease, making it unsuitable for this scenario. - Its strong smell and propensity to cause coughing and laryngospasm make it contraindicated during induction in patients at risk for bronchospasm.

Question 9: A construction worker met with an accident when a cement block fell on his face. He sustained severe maxillofacial and laryngeal injury. He was not able to open his mouth and is having jaw fracture with obstruction in nasopharynx and oropharynx. To stabilize his airway, the following procedure was done on him. Which option describes the procedure done on him?

A. Cricothyroidotomy
B. Subcutaneous tracheostomy
C. Tracheostomy (Correct Answer)
D. Submental insertion of ET

Explanation: ***Tracheostomy*** - A tracheostomy creates a surgical opening in the **trachea** to establish a direct airway, bypassing the upper airway. This is crucial when the **nasopharynx and oropharynx are obstructed** due to severe maxillofacial and laryngeal injuries, as described in the case. - The procedure allows for ventilation and prevents aspiration, making it the most suitable long-term solution for definitive airway management in patients with extensive facial and jaw trauma preventing oral or nasal intubation. *Cricothyroidotomy* - This procedure involves making an incision through the **cricothyroid membrane** into the trachea. It is typically a **rapid, emergency airway** procedure. - While it provides an immediate airway, it is generally considered a temporary measure due to potential complications like **subglottic stenosis** with prolonged use, and not ideal for the described severe, multifocal obstruction requiring a more stable, long-term solution. *Subcutaneous tracheostomy* - This term is **not a recognized medical procedure** for establishing an airway. - Tracheostomies are performed with direct access to the trachea, not subcutaneously. *Submental insertion of ET* - This technique involves passing an endotracheal tube through a submental incision into the oropharynx, bypassing the mouth in cases of **maxillofacial trauma** and securing the airway. - However, the question describes **obstruction in both the nasopharynx and oropharynx**, and also a laryngeal injury, which would likely preclude the passage of an endotracheal tube even via a submental approach, making a direct tracheal access (tracheostomy) a more appropriate and definitive solution.

Question 10: Recommended illumination range for regular work is _______ foot-candles.

A. 75-100
B. 10-25
C. 50-75
D. 25-50 (Correct Answer)

Explanation: ***25-50*** - For **regular work** or tasks requiring moderate visual effort, an illumination range of **25-50 foot-candles** (250-500 lux) is generally recommended to ensure adequate visibility and comfort. - This range balances sufficient light for tasks like **reading** or **writing** without causing glare or excessive energy consumption. *75-100* - An illumination range of **75-100 foot-candles** (750-1000 lux) is typically reserved for **tasks requiring precise visual acuity** or where fine details must be observed, such as intricate assembly work or detailed inspections. - Using such high illumination for regular work can lead to **eye strain** and excessive energy use. *10-25* - A range of **10-25 foot-candles** (100-250 lux) is suitable for **general lighting** in areas requiring minimal visual tasks, like hallways, lounges, or waiting areas where reading or close work is not primary. - This level is usually **insufficient for sustained regular work**, which often involves reading or writing. *50-75* - **50-75 foot-candles** (500-750 lux) is often recommended for **more demanding office work** or tasks involving prolonged reading of small print, which is a step above regular general work. - While it could be acceptable for some regular work, **25-50 foot-candles** is a more common and energy-efficient recommendation for general regular tasks.

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