A 70 year old patient with benign prostatic hyperplasia underwent transuretheral resection of prostate under spinal anaesthesia. One hour later, he developed vomiting and altered sensorium. The most probable cause is –
**Core Concept**
Spinal anesthesia can lead to hypotension due to sympathetic blockade, potentially causing inadequate blood flow to the gastrointestinal system and subsequent nausea, vomiting, and altered sensorium.
**Why the Correct Answer is Right**
In this scenario, the patient developed hypotension due to spinal anesthesia, which can cause decreased perfusion of the gastrointestinal system. This decreased perfusion can lead to the release of vasopressin and other vasoactive substances, causing nausea and vomiting. The altered sensorium can be attributed to the hypotension and subsequent cerebral hypoperfusion. The patient's age and the presence of benign prostatic hyperplasia may have contributed to an increased sensitivity to the effects of spinal anesthesia.
**Why Each Wrong Option is Incorrect**
* **Option A:** This option is not directly related to the scenario described. While it is true that spinal anesthesia can cause respiratory depression, the patient's symptoms of vomiting and altered sensorium are more consistent with hypotension and decreased gastrointestinal perfusion.
* **Option B:** This option is not relevant to the scenario. While spinal anesthesia can cause urinary retention, it is not the most probable cause of the patient's symptoms of vomiting and altered sensorium.
* **Option C:** This option is incorrect because it is not directly related to the scenario. While spinal anesthesia can cause hypotension, it is not the most probable cause of the patient's symptoms of vomiting and altered sensorium.
**Clinical Pearl / High-Yield Fact**
Spinal anesthesia can cause hypotension due to sympathetic blockade, which can lead to decreased gastrointestinal perfusion and subsequent nausea, vomiting, and altered sensorium. This is particularly important in patients with benign prostatic hyperplasia, as they may be more sensitive to the effects of spinal anesthesia.
**Correct Answer:** **D**