NEET-PG 2013 Anesthesiology MCQs — Questions 31–33 (Page 4 of 4)

Q: Which anaesthetic drug contributes to green house effect?

Desflurane. **Desflurane** - **Desflurane** has the highest **global warming potential (GWP)** among commonly used volatile anesthetics, primarily due to its long atmospheric half-life and potent infrared absorption. - Its environmental impact is also amplified by its high **minimum alveolar concentration (MAC)** and low blood solubility, requiring higher delivered concentrations for anesthesia. *Enflurane* - **Enflurane** has a lower GWP compared to desflurane and is less commonly used in modern practice. - While it contributes to the greenhouse effect, its impact is significantly less than that of desflurane due to differences in chemical structure and atmospheric persistence. *Sevoflurane* - **Sevoflurane** has a relatively low GWP and a short atmospheric half-life compared to desflurane, making it a more environmentally friendly option among volatile anesthetics. - Although it still contributes to atmospheric warming, its overall environmental impact is considerably less than desflurane's. *Halothane* - **Halothane** is a potent greenhouse gas but is no longer used in many parts of the world due to concerns about hepatotoxicity and its significant ozone-depleting potential. - While it contributes to atmospheric warming, its current lack of clinical use limits its ongoing contribution to the greenhouse effect compared to currently utilized agents.

Q: Regarding propofol, which one of the following statements is false?

It causes severe vomiting. ***It causes severe vomiting*** - Propofol is actually known for its **antiemetic properties**, meaning it helps *prevent* rather than cause nausea and vomiting. - This makes it a preferred anesthetic for procedures where **postoperative nausea and vomiting (PONV)** are a concern. *It is used as an intravenous induction agent* - **Propofol** is a widely used **intravenous anesthetic** for the **induction and maintenance of general anesthesia**. - It provides a rapid onset of unconsciousness due to its high lipid solubility. *It is painful on injecting intravenously* - Injection of propofol can often cause **pain at the injection site**, particularly when administered into smaller veins. - This pain can be mitigated by co-administering **lidocaine** or using larger veins. *It has no muscle relaxant property* - Propofol does **not possess intrinsic muscle relaxant properties**; patients require additional neuromuscular blocking agents for surgical relaxation. - It facilitates intubation by causing **loss of consciousness** and **reducing airway reflexes**, but does not directly relax skeletal muscles.

Q: The inducing agent of choice in shock -

Ketamine. **Ketamine** * **Ketamine** is preferred in shock due to its sympathomimetic properties, which maintain or increase blood pressure and heart rate, thus preserving **cardiovascular stability**. * It also has minimal respiratory depression and bronchodilatory effects, making it safer for patients with compromised respiratory function. * The cardiovascular stimulating effects of ketamine helps maintain haemodynamic stability in shocked patients. It maintains cerebral autoregulation and perfusion of vital organs. *Isoflurane* * **Isoflurane** is an inhaled anesthetic that typically causes **dose-dependent myocardial depression** and **vasodilation**, which can worsen hypotension in a shock state. * It can significantly decrease systemic vascular resistance, thereby exacerbating the already compromised cardiovascular status of a shock patient. *Desflurane* * **Desflurane** is an inhaled anesthetic known for its rapid onset and offset but can cause a **significant increase in heart rate and blood pressure** upon rapid concentration changes, which may be detrimental in an unstable patient. * Like isoflurane, it also causes dose-dependent peripheral vasodilation and myocardial depression, which can worsen hypotension in patients in shock. *Thiopentone* * **Thiopentone** is a barbiturate that causes significant **myocardial depression** and **peripheral vasodilation**, leading to a substantial drop in blood pressure. * Its use in shock would further compromise cardiovascular stability and is generally contraindicated due to its potent hemodynamic depressant effects.

Q31

Which anaesthetic drug contributes to green house effect?

Q32

Regarding propofol, which one of the following statements is false?

Q33

The inducing agent of choice in shock -

NEET-PG 2013 — Anesthesiology