Obstetric Anesthesia — MCQs

Obstetric Anesthesia Indian Medical PG Practice Questions and MCQs

Question 41: Anesthetic agent of choice as epidural anesthesia in labour is?

A. Prilocaine
B. Bupivacaine (Correct Answer)
C. Procaine
D. Lignocaine

Explanation: ***Bupivacaine*** - **Bupivacaine** is the preferred agent for epidural anesthesia in labor due to its **long duration of action** and ability to produce good sensory block with minimal motor block. - This allows for effective pain relief during labor while preserving the mother's ability to push during delivery. *Prilocaine* - **Prilocaine** has a **shorter duration of action** and a higher risk of causing **methemoglobinemia** at doses required for effective labor epidural. - It is generally not recommended for obstetric epidural anesthesia. *Procaine* - **Procaine** is an **ester-type** local anesthetic with a very short duration of action, making it unsuitable for continuous epidural pain relief during labor. - It also has a higher incidence of **allergic reactions** compared to amide-type local anesthetics. *Lignocaine* - While **lignocaine** (lidocaine) can be used for epidural anesthesia, its **shorter duration of action** compared to bupivacaine often necessitates more frequent dosing or continuous infusion at higher concentrations. - Higher concentrations of lignocaine can lead to more significant motor block, potentially interfering with the pushing phase of labor.

Question 42: Best treatment for relieving pain during intrapartum period is:

A. Epidural anesthesia (Correct Answer)
B. General Anesthesia
C. Spinal anesthesia
D. IV ketamine

Explanation: ***Epidural anesthesia*** - Provides **continuous pain relief** during labor, allowing mobility and control over medication dosage through patient-controlled epidural analgesia (PCEA). - It is effective for both vaginal and cesarean deliveries, offering superior pain control compared to other methods while maintaining maternal consciousness. *General Anesthesia* - Involves a **complete loss of consciousness** and is primarily reserved for emergency cesarean sections due to its associated risks for both mother and baby. - It is unsuitable for routine labor pain management as it prevents maternal participation and response during delivery. *Spinal anesthesia* - Provides **rapid, intense pain relief** but is typically a single-shot injection with a shorter duration of action compared to epidural anesthesia. - It is often used for planned cesarean sections or for a rapid, profound block during the late stages of labor, but it does not allow for long-term, dynamic pain management like an epidural. *IV ketamine* - Can be used for pain relief in lower doses, but it can cause **sedation, hallucinations, and dysphoria**, which are undesirable during labor. - While it's a potent analgesic, its side effect profile makes it a less favorable choice than regional anesthesia for routine intrapartum pain relief.

Question 43: A 30 year old woman with coarctation of aorta is admitted to the labour room for elective caesarean section. Which of the following is the anaesthesia technique of choice -

A. Epidural anaesthesia
B. Spinal anaesthesia
C. General anaesthesia (Correct Answer)
D. Local anaesthesia with nerve blocks

Explanation: ***General anaesthesia*** - In patients with **coarctation of the aorta**, general anaesthesia is often preferred for caesarean section to maintain **hemodynamic stability** and carefully control **cardiovascular responses**. - Rapid changes in blood pressure and heart rate associated with regional anaesthesia can increase the risk of **aortic dissection** or **rupture** due to the stress on the weakened aorta. *Epidural anaesthesia* - While epidural anaesthesia offers **gradual onset** and titration, the controlled hypotension it induces can still be risky in coarctation patients if not managed meticulously. - The potential for **sympathetic blockade** and associated blood pressure changes might compromise perfusion to vital organs distal to the coarctation. *Spinal anaesthesia* - **Spinal anaesthesia** causes a rapid and profound sympathetic blockade, leading to a sudden drop in systemic vascular resistance and blood pressure. - This abrupt change significantly increases the risk of **aortic dissection** or severe **hypotension** distal to the coarctation, making it highly dangerous for this patient population. *Local anaesthesia with nerve blocks* - **Local anaesthesia** with nerve blocks alone is generally insufficient for a caesarean section, as it would not provide adequate surgical anaesthesia or uterine muscle relaxation. - While it has minimal systemic hemodynamic effects, its inadequacy for the surgical procedure itself makes it an impractical choice for coarctation patients undergoing caesarean section.

Question 44: Anesthesia of choice for cesarean section in severe preeclampsia:-

A. Spinal (Correct Answer)
B. GA
C. Epidural
D. Combined spinal-epidural (CSE)

Explanation: ***Spinal*** - **Spinal anesthesia** is generally preferred in severe preeclampsia because it provides **rapid onset** of dense block, which can be critical for emergent cesarean sections. - It avoids the risks associated with general anesthesia in these patients, such as difficult intubation and exaggerated **hypertensive response** to laryngoscopy. *GA* - **General anesthesia (GA)** in severe preeclampsia carries increased risks due to **airway edema**, potential for difficult intubation, and significant **blood pressure fluctuations** during induction and intubation. - It can exacerbate the already compromised uteroplacental perfusion due to the sympathetic blockade and the potential for a **hypotensive episode**. *Epidural* - While generally safe in less severe preeclampsia, an **epidural** has a **slower onset** compared to spinal anesthesia, which may be a disadvantage in emergent situations. - The gradual sympathetic blockade with an epidural is often preferred to avoid sudden drops in blood pressure, but the delay in achieving a surgical block might not be acceptable in severe, unstable cases. *Combined spinal-epidural (CSE)* - **Combined spinal-epidural (CSE)** offers the rapid onset of a spinal block with the flexibility of an epidural catheter for prolonged anesthesia or postoperative pain control. - However, in cases of severe preeclampsia where **hemodynamic instability** is a major concern, the relatively larger dose of local anesthetic required for epidural component can lead to a more pronounced or rapid drop in blood pressure.

Question 45: A 30-year-old female in her third trimester of pregnancy presents for emergency surgery requiring immediate intervention. What is the most appropriate anesthetic plan for this patient?

A. Spinal anesthesia with low-dose bupivacaine
B. Regional anesthesia with minimal sedation
C. Epidural anesthesia with continuous infusion
D. General anesthesia with rapid sequence induction (Correct Answer)

Explanation: ***General anesthesia with rapid sequence induction*** - **Rapid sequence induction (RSI)** is crucial in pregnant patients due to **increased risk of aspiration** from delayed gastric emptying and increased intra-abdominal pressure. - An emergency surgery requiring **immediate intervention** precludes the time needed for regional anesthesia to take full effect and ensures optimal fetal monitoring and management. *Spinal anesthesia with low-dose bupivacaine* - While spinal anesthesia is a common choice for *elective* C-sections, it may not be suitable for **emergency surgery requiring immediate intervention** due to the time lag in onset and potential for maternal hypotension, which can compromise fetal oxygenation. - **Low-dose bupivacaine** might not provide adequate surgical anesthesia rapidly enough for an emergent procedure, and the urgency often necessitates a quicker onset. *Epidural anesthesia with continuous infusion* - Epidural anesthesia has a **slower onset** compared to spinal or general anesthesia, making it inappropriate for an emergency situation requiring immediate intervention. - A **continuous infusion** is better suited for prolonged procedures or labor analgesia, not for an urgent surgical start. *Regional anesthesia with minimal sedation* - **Regional anesthesia** in general, including spinals and epidurals, takes time to administer and achieve full effect, which may not be compatible with the need for immediate surgical intervention. - **Minimal sedation** might be insufficient if the patient is anxious or if the surgical field is extensive or requires deep tissue manipulation, which can lead to patient discomfort and movement.

Question 46: What is the preferred position for a patient undergoing spinal anesthesia for a cesarean section?

A. Supine
B. Trendelenburg
C. Lateral decubitus (Correct Answer)
D. Sitting

Explanation: ***Lateral decubitus*** - The **lateral decubitus position** (left or right side-lying) is commonly preferred for spinal anesthesia in pregnant women. - This position helps prevent **aortocaval compression**, which can occur in the supine position due to the gravida uterus compressing the great vessels. *Supine* - The **supine position** is generally avoided for spinal anesthesia in pregnant women due to the risk of **aortocaval compression**. - This compression can lead to **maternal hypotension** and reduced placental perfusion, posing risks to both mother and fetus. *Trendelenburg* - The **Trendelenburg position** involves placing the patient head-down. - While it can be used in some situations to manage hypotension, it is **not the preferred initial position** for administering spinal anesthesia, especially in pregnant patients. *Sitting* - The **sitting position** can be used for spinal anesthesia, as it allows for easy identification of the intervertebral spaces due to **flexion of the lumbar spine**. - However, for pregnant women, it may be less comfortable and still carries some risk of **hypotension** if not carefully managed.

Question 47: A 30-year-old pregnant woman is scheduled for an elective cesarean section. Which inhalational agent has the least effect on uteroplacental blood flow?

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

Explanation: ***Isoflurane*** - Isoflurane causes **minimal suppression of uterine contractions** and has the **least effect on uteroplacental blood flow** compared to other volatile anesthetics, making it suitable for pregnant patients. - Its **low solubility** allows for rapid emergence, which is beneficial for maternal-fetal well-being. *Desflurane* - Desflurane, while having a very **low blood-gas solubility** and rapid onset/offset, can cause a **higher incidence of maternal hypertension and tachycardia**, potentially compromising uteroplacental blood flow. - Its tendency to cause a more pronounced **sympathetic response** makes it less ideal for maintaining stable uteroplacental perfusion compared to isoflurane. *Nitrous oxide* - While nitrous oxide is often used in obstetric anesthesia, it provides **poor uterine relaxation** and can lead to **diffusional hypoxia** in the mother if not appropriately managed during emergence. - It's typically used as an adjunct to other agents rather than a sole anesthetic, and in higher concentrations, it can still negatively impact uteroplacental circulation. *Sevoflurane* - Sevoflurane provides **good uterine relaxation** and smooth induction, but it tends to cause **more uterine atony** and bleeding compared to isoflurane at equipotent concentrations. - Its **higher impact on uterine tone** can compromise uteroplacental blood flow more significantly than isoflurane, especially during the maintenance phase.

Question 48: Which volatile anesthetic agent is MOST commonly recognized for its clinically significant tocolytic effects in obstetric anesthesia?

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

Explanation: ***Isoflurane*** - **Isoflurane** is well-known for its potent dose-dependent uterine relaxation (tocolytic) properties, which can be clinically useful during obstetric procedures requiring uterine quiescence, such as manual placenta removal or fetal manipulation. - This effect is due to its ability to decrease the frequency and intensity of uterine contractions by relaxing myometrial smooth muscle. *Sevoflurane* - While sevoflurane does possess uterine relaxant properties, its tocolytic effect is generally considered less potent compared to isoflurane at equipotent doses. - It is frequently favored for maintenance of anesthesia in obstetrics due to its rapid onset and offset, but its uterine relaxation is often less pronounced than that of isoflurane. *Desflurane* - Desflurane also causes dose-dependent uterine relaxation, but its tocolytic effects are not typically considered as significant or as commonly utilized for specific uterine relaxation needs as isoflurane. - Its rapid pharmacokinetics make it suitable for obstetric anesthesia, but its uterine effects are generally in line with other volatile agents, with isoflurane having a more pronounced reputation for tocolysis. *Nitrous oxide* - **Nitrous oxide** has minimal to no direct significant uterine relaxant (tocolytic) effects, making it a common choice for analgesia during labor in sub-anesthetic concentrations. - It does not cause the widespread smooth muscle relaxation observed with potent volatile agents, hence is not used for obstetric scenarios requiring uterine quiescence.

Question 49: Which anesthetic agents are known to have tocolytic effects?

A. Enflurane
B. Halothane
C. Isoflurane
D. All of the options (Correct Answer)

Explanation: ***All of the options*** - **Inhaled halogenated anesthetics** (e.g., enflurane, halothane, isoflurane, sevoflurane, desflurane) all have dose-dependent tocolytic effects. - This property is due to their ability to **relax uterine smooth muscle**, which can be beneficial in certain obstetric situations (e.g., uterine relaxation for fetal manipulation) but can also increase the risk of postpartum hemorrhage. *Enflurane* - Enflurane is an **inhaled anesthetic** that, like other halogenated agents, exhibits tocolytic properties. - It causes **uterine smooth muscle relaxation**, which can inhibit labor or aid in uterine manipulation during surgery. *Halothane* - Halothane is another **volatile anesthetic** known for its significant tocolytic effects. - It was historically used for uterine relaxation but is less common now due to its potential for **myocardial depression** and arrhythmias. *Isoflurane* - Isoflurane is a commonly used **inhaled anesthetic** with demonstrable tocolytic activity. - Its ability to relax the uterus makes it useful in scenarios requiring uterine quiescence, such as during a **retained placenta** or uterine inversion.

Question 50: A lower segment caesarean section (LSCS) can be carried out under all the following techniques of anesthesia, except:

A. Spinal anaesthesia
B. Caudal anaesthesia (Correct Answer)
C. Combined Spinal Epidural anaesthesia
D. General anaesthesia

Explanation: ***Caudal anaesthesia*** - Caudal anesthesia provides analgesia for the **perineum** and **lower limbs**, making it unsuitable for the extensive surgical field required for a lower segment caesarean section (LSCS). - The level of block achieved with caudal anesthesia is typically not high enough to adequately anesthetize the **uterus**, abdominal wall, and surrounding structures for an LSCS. *Spinal anaesthesia* - Spinal anesthesia is a common and effective method for LSCS, providing rapid onset of **dense sensory and motor block** essential for surgery. - It involves injecting a local anesthetic directly into the **subarachnoid space**, leading to a high-quality block for abdominal surgery. *Combined Spinal Epidural anaesthesia* - **Combined spinal-epidural (CSE) anesthesia** offers the rapid onset of a spinal block with the flexibility of an epidural catheter for prolonged anesthesia or postoperative pain relief. - This technique is highly suitable for LSCS, allowing for precise control over the block level and duration. *General anaesthesia* - General anesthesia is a viable option for LSCS, particularly in emergencies or when regional techniques are contraindicated. - It involves inducing a state of **unconsciousness** and muscle relaxation, requiring intubation and mechanical ventilation.

Practice by Chapter

Physiological Changes in Pregnancy

Practice Questions

Labor Analgesia: Epidural and Combined Spinal-Epidural

Practice Questions

Anesthesia for Cesarean Delivery

Practice Questions

Difficult Airway in Obstetrics

Practice Questions

Preeclampsia and Eclampsia Management

Practice Questions

Obstetric Hemorrhage

Practice Questions

Amniotic Fluid Embolism

Practice Questions

Maternal Comorbidities

Practice Questions

High-Risk Obstetric Anesthesia

Practice Questions

Fetal Monitoring and Fetal Distress

Practice Questions

Postpartum Tubal Ligation

Practice Questions

Postdural Puncture Headache

Practice Questions

Want unlimited practice?

Get full access to all questions, explanations, and performance tracking.

Start For Free