(Option A) Fine-needle aspiration (FNA) biopsy: This is the most valuable initial test when evaluating a thyroid nodule. During FNA, a thin needle is inserted into the nodule to obtain a sample of cells or tissue. These cells are then examined under a microscope to determine whether the nodule is benign (non-cancerous) or malignant (cancerous). FNA biopsy provides crucial information about the nature of the nodule and helps guide further management and treatment decisions.

(Option B) Serum calcium levels: Serum calcium levels are not the primary investigation for evaluating a thyroid nodule. Elevated serum calcium levels may suggest hyperparathyroidism, a separate condition that involves the parathyroid glands, not the thyroid gland.

(Option C) Ultrasound of the neck: While an ultrasound of the neck is a valuable imaging tool to assess the size, characteristics, and location of a thyroid nodule, it alone cannot definitively determine whether the nodule is benign or malignant. It is often used in conjunction with other tests, such as FNA biopsy, to aid in diagnosis.

(Option D) Thyroid function tests (TFTs): Thyroid function tests measure the levels of thyroid hormones (T3 and T4) and thyroid-stimulating hormone (TSH) in the blood. While TFTs are important for assessing overall thyroid function, they are not the primary investigation for evaluating the nature of a thyroid nodule. TFTs are more commonly used to assess thyroid function in cases of hyperthyroidism or hypothyroidism.

Subject: Surgery

System: Endocrine

Topic: Thyroid Nodule

(Option D) Secondary hemorrhage: Secondary hemorrhage is a known complication after splenectomy, where there is bleeding from the surgical site after an initially successful surgery. The symptoms of secondary hemorrhage can include tachycardia, hypotension, and decreased urine output. This is the most likely issue in this case, given the patient's history of splenectomy and the presentation of tachycardia, hypotension, and decreased urine output. The patient should be evaluated and treated promptly for this condition.

(Option A) Basal atelectasis: This is a condition where there is a collapse or incomplete inflation of the lungs, typically affecting the lower regions of the lungs. While atelectasis can cause tachycardia (elevated heart rate), it is unlikely to cause hypotension (low blood pressure) and decreased urine output, which are the key findings in this case.

(Option B) Gastric perforation: Gastric perforation is a serious complication that can occur after abdominal surgery, where there is a hole or tear in the stomach lining, leading to leakage of stomach contents into the abdominal cavity. While gastric perforation can cause tachycardia, it typically presents with abdominal pain, tenderness, and signs of peritonitis (inflammation of the abdominal lining), which are not mentioned.

(Option C) Portal vein thrombosis: Portal vein thrombosis is a blood clot that forms in the portal vein, which carries blood from the digestive organs to the liver. While portal vein thrombosis can cause hypotension and decreased urine output, it typically presents with abdominal pain, jaundice, and gastrointestinal bleeding, which are not mentioned.

Subject: Surgery

System: GIT

Topic: Splenectomy Complication

(Option B) Automatic micturition reflex: After several months of supportive care following a severe injury in the lower thoracic region of the spinal cord, the patient would most likely develop an automatic micturition reflex. This reflex is also known as the "spinal reflex bladder." It occurs when the spinal cord below the level of injury becomes hyperreflexic due to the loss of supraspinal control.

When the spinal cord is severed or damaged, the communication between the brain and the lower part of the spinal cord is disrupted. In this case, the lower part of the spinal cord, responsible for controlling bladder function, is detached from the upper part.

(Option A) Complete absence of bladder tone: If the injury is severe and the patient develops a complete detachment of the lower part of the spinal cord from the upper part, it is likely that there will be a complete absence of bladder tone. Without supraspinal control, the bladder loses its ability to contract and relax in a coordinated manner, resulting in flaccid or atonic bladder. This can lead to urinary retention and the inability to initiate micturition voluntarily.

(Option C) Frequent desire to micturate: Frequent desire to micturate, also known as urinary frequency, is less likely. Since the lower part of the spinal cord is detached from the upper part, there is a disruption in the communication between the bladder and the brain. As a result, the sensation of a full bladder and the desire to urinate may be diminished or absent. This can lead to urinary retention rather than frequent desire to micturate.

(Option D) Urge incontinence: Urge incontinence refers to the involuntary loss of urine associated with a strong, sudden desire to urinate. It typically occurs due to an overactive bladder or neurological conditions that disrupt bladder control. In this scenario, where the lower part of the spinal cord is detached from the upper part, the ability to perceive and respond to the sensation of a full bladder is impaired. Therefore, the patient is less likely to experience the sudden urge to urinate that characterizes urge incontinence.

Subject: Surgery

System: Nervous System

Topic: Spinal Cord Injury and Bladder Dysfunction

(Option C) Electrocardiogram (ECG): An electrocardiogram, commonly known as an ECG or EKG, is a diagnostic test that records the electrical activity of the heart over a period of time.

It is commonly performed during the preoperative workup to assess cardiac risk because it can detect various cardiac abnormalities such as arrhythmias, ischemia, or previous heart attacks.

An ECG provides valuable information about the heart's rhythm and function, helping healthcare providers identifies potential cardiac issues that could impact a patient's ability to undergo surgery safely.

(Option A) Serum electrolyte panel: A serum electrolyte panel measures the levels of electrolytes such as sodium, potassium, chloride, and bicarbonate in the blood.

While it is an important test for assessing overall health, it is not specifically used to assess cardiac risk in the preoperative setting.

(Option B) Pulmonary function tests: Pulmonary function tests are used to assess lung function and are primarily focused on evaluating a patient's respiratory health.

They help in determining if a patient has any lung conditions or respiratory issues but are not directly related to assessing cardiac risk.

(Option D) Complete blood count (CBC): A complete blood count is a blood test that measures different components of the blood, including red blood cells, white blood cells, and platelets.

While a CBC is a standard test in preoperative evaluations to check for overall health and to identify conditions like anemia or infection, it is not specific to assessing cardiac risk.

Subject: Surgery

Main Topic: Perioperative Care

Sub Topic: Cardiac Risk Assessment in Perioperative Care

(Option B) Renal cell carcinoma: Renal cell carcinoma is a type of kidney cancer that often presents with symptoms like hematuria, flank pain, and a solid, enhancing renal mass on imaging. Smoking is a known risk factor for renal cell carcinoma, which further supports this diagnosis.

(Option A) Benign prostatic hyperplasia (BPH): BPH is a non-cancerous enlargement of the prostate gland, which is located in the male urinary system. It can cause urinary symptoms like difficulty urinating, but it typically does not present with hematuria (blood in the urine).

(Option C) Bladder cancer: Bladder cancer can also cause hematuria, but it usually arises in the bladder itself, not in the renal (kidney) tissue. While bladder cancer can sometimes be seen on imaging studies, it typically presents with different patterns and characteristics on imaging than renal cell carcinoma.

(Option D) Testicular cancer: Testicular cancer usually presents as a painless mass or lump in the testicles. It does not typically cause hematuria or have imaging findings in the kidneys.

Subject: Surgery

System: Renal System (Genitournary)

Topic: Renal Mass with Hematuria

(Option C) Venography: Venography is considered the gold standard for diagnosing DVT. This procedure involves injecting a contrast dye into a large vein, usually in the foot, and taking X-ray images to visualize the blood flow in the deep veins of the legs. Venography provides a direct and highly accurate assessment of the presence and location of blood clots in the deep veins. However, it is an invasive procedure and is typically reserved for cases where the diagnosis is uncertain or when precise information about clot location is essential.

(Option A) Doppler ultrasound: Doppler ultrasound is a commonly used non-invasive imaging technique for diagnosing DVT. It works by using sound waves to create images of blood flow in the veins, allowing healthcare providers to visualize blood clots in the deep veins of the legs. While Doppler ultrasound is a sensitive and specific test for DVT, it is not considered the gold standard because it may miss some smaller or less accessible clots.

(Option B) D-dimer assay: The D-dimer assay is a blood test that measures the presence of a substance called D-dimer, which is released into the bloodstream when a blood clot breaks up. It is a useful initial screening test for DVT and pulmonary embolism (PE) because elevated D-dimer levels may suggest the presence of a clot. However, D-dimer levels can be elevated for various reasons other than DVT, such as inflammation, surgery, or pregnancy. Therefore, a positive D-dimer test alone is not sufficient for a definitive diagnosis of DVT and must be followed by imaging studies.

(Option C) Magnetic resonance imaging (MRI): MRI is a non-invasive imaging technique that can be used to diagnose DVT. It uses magnetic fields and radio waves to create detailed cross-sectional images of the body. While MRI can provide high-quality images and is useful for detecting DVT, it is not as commonly used as venography or ultrasound for routine DVT diagnosis. It may be reserved for specific situations, such as when other imaging methods are inconclusive or when a patient cannot undergo contrast-based imaging.

Subject: Surgery

System: Vascular

Topic: Deep Vein Thrombosis (DVT)