Urgent vs emergent conditions recognition US Medical PG Practice Questions and MCQs
Practice US Medical PG questions for Urgent vs emergent conditions recognition. These multiple choice questions (MCQs) cover important concepts and help you prepare for your exams.
Urgent vs emergent conditions recognition US Medical PG Question 1: A 27-year-old man presents to the emergency department for altered mental status. The patient was found napping in a local market and brought to the hospital. The patient has a past medical history of polysubstance abuse and is homeless. His temperature is 104°F (40.0°C), blood pressure is 100/52 mmHg, pulse is 133/min, respirations are 25/min, and oxygen saturation is 99% on room air. Physical exam is notable for an altered man. Cardiopulmonary exam reveals a murmur over the left lower sternal border. A bedside ultrasound reveals a vegetation on the tricuspid valve. The patient is ultimately started on IV fluids, norepinephrine, vasopressin, vancomycin, and piperacillin-tazobactam. A central line is immediately placed in the internal jugular vein and the femoral vein secondary to poor IV access. Cardiothoracic surgery subsequently intervenes to remove the vegetation. While recovering in the ICU, days 3-5 are notable for an improvement in the patient’s symptoms. Two additional peripheral IVs are placed while in the ICU on day 5, and the femoral line is removed. On day 6, the patient's fever and hemodynamic status worsen. Though he is currently responding and not complaining of any symptoms including headache, photophobia, neck stiffness, or pain, he states he is feeling weak. Jolt accentuation of headache is negative and his abdominal exam is benign. A chest radiograph, urinalysis, and echocardiogram are unremarkable though the patient’s blood cultures are positive when drawn. Which of the following is the best next step in management?
- A. Add micafungin to the patient’s antibiotics
- B. Perform a lumbar puncture
- C. Remove all peripheral IV’s and send for cultures
- D. Add cefepime to the patient’s antibiotics
- E. Remove the central line and send for cultures (Correct Answer)
Urgent vs emergent conditions recognition Explanation: **Correct: Remove the central line and send for cultures**
- The patient's worsening fever and hemodynamic instability on day 6, despite initial improvement, raise suspicion for a **catheter-related bloodstream infection (CRBSI)**, especially given the history of central line placement.
- **Prompt removal of the catheter** and sending the tip for culture is crucial for diagnosis and treatment of potential CRBSI, as the source of infection often resides within the biofilm on the catheter.
*Incorrect: Remove all peripheral IV's and send for cultures*
- While **peripheral IVs** can be a source of infection, the central line was placed earlier and is associated with a much higher risk of serious infection, especially in a critically ill patient.
- The patient's initial improvement followed by deterioration points more towards a **central line-associated infection** rather than new peripheral IVs placed only on day 5.
*Incorrect: Perform a lumbar puncture*
- Although the patient has altered mental status, the absence of focal neurological deficits, headache, photophobia, and neck stiffness, along with a negative **Jolt accentuation of headache**, makes **meningitis** less likely as the primary cause of deterioration.
- The more immediate and likely cause of worsening sepsis in this context is a **catheter-related infection**.
*Incorrect: Add micafungin to the patient's antibiotics*
- Adding an antifungal agent such as **micafungin** would be considered if there was a strong suspicion of a fungal infection, which is not indicated by the current blood cultures or clinical picture.
- Empiric antifungal therapy is typically reserved for patients with persistent fever refractory to broad-spectrum antibiotics, known fungal exposure, or specific risk factors.
*Incorrect: Add cefepime to the patient's antibiotics*
- The patient is already on **vancomycin and piperacillin-tazobactam**, which provides broad-spectrum coverage for both gram-positive and gram-negative bacteria, including *Pseudomonas aeruginosa*.
- Adding **cefepime** would broaden gram-negative coverage further but is usually unnecessary unless the current regimen is failing due to specific resistant organisms, and the more likely source of infection should be addressed first.
Urgent vs emergent conditions recognition US Medical PG Question 2: A 57-year-old man was brought into the emergency department unconscious 2 days ago. His friends who were with him at that time say he collapsed on the street. Upon arrival to the ED, he had a generalized tonic seizure. At that time, he was intubated and is being treated with diazepam and phenytoin. A noncontrast head CT revealed hemorrhages within the pons and cerebellum with a mass effect and tonsillar herniation. Today, his blood pressure is 110/65 mm Hg, heart rate is 65/min, respiratory rate is 12/min (intubated, ventilator settings: tidal volume (TV) 600 ml, positive end-expiratory pressure (PEEP) 5 cm H2O, and FiO2 40%), and temperature is 37.0°C (98.6°F). On physical examination, the patient is in a comatose state. Pupils are 4 mm bilaterally and unresponsive to light. Cornea reflexes are absent. Gag reflex and cough reflex are also absent. Which of the following is the next best step in the management of this patient?
- A. Second opinion from a neurologist
- B. Withdraw ventilation support and mark time of death
- C. Electroencephalogram
- D. Repeat examination in several hours
- E. Apnea test (Correct Answer)
Urgent vs emergent conditions recognition Explanation: ***Apnea test***
- The patient exhibits classic signs of **brain death**, including a **coma**, fixed and dilated pupils, and absent brainstem reflexes (corneal, gag, cough). The next step is to perform an apnea test to confirm the absence of spontaneous respiratory drive.
- An apnea test confirms brain death by demonstrating the **absence of respiratory effort** despite a rising pCO2, provided that spinal cord reflexes are not mistaken for respiratory efforts.
*Second opinion from a neurologist*
- While consulting a neurologist is often helpful in complex neurological cases, the current clinical picture presents such clear signs of brain death that **further confirmatory testing** for brain death (like the apnea test) is more immediately indicated before seeking additional opinions on diagnosis.
- A second opinion would typically be sought to confirm the diagnosis or guide management, but establishing brain death requires a specific protocol which is incomplete without the apnea test.
*Withdraw ventilation support and mark time of death*
- It is **premature to withdraw ventilation** before brain death is unequivocally confirmed by all necessary clinical and confirmatory tests, including the apnea test.
- Withdrawing support without full confirmation could lead to ethical and legal issues, as the patient might still have residual brainstem function, however minimal.
*Electroencephalogram*
- An **EEG** can show absent electrical activity, supporting brain death, but it is **not a mandatory part of the core brain death criteria** in many protocols, especially when clinical signs are clear and an apnea test can be performed.
- The primary diagnostic criteria for brain death usually prioritize clinical examination and the apnea test for proving irreversible cessation of all brain functions.
*Repeat examination in several hours*
- Repeating the examination in several hours is typically done if there are **confounding factors** (e.g., severe hypothermia, drug intoxication) that might mimic brain death, or if the initial assessment is incomplete.
- In this case, there are no mentioned confounding factors, and the immediate priority is to complete the brain death protocol with an apnea test, given the current clear clinical picture.
Urgent vs emergent conditions recognition US Medical PG Question 3: A 65-year-old man presents to the emergency department for sudden weakness. He was doing mechanical work on his car where he acutely developed right-leg weakness and fell to the ground. He is accompanied by his wife, who said that this has never happened before. He was last seen neurologically normal approximately 2 hours prior to presentation. His past medical history is significant for hypertension and type II diabetes. His temperature is 98.8°F (37.1°C), blood pressure is 177/108 mmHg, pulse is 90/min, respirations are 15/min, and oxygen saturation is 99% on room air. Neurological exam reveals that he is having trouble speaking and has profound weakness of his right upper and lower extremity. Which of the following is the best next step in management?
- A. Thrombolytics
- B. Noncontrast head CT (Correct Answer)
- C. CT angiogram
- D. MRI of the head
- E. Aspirin
Urgent vs emergent conditions recognition Explanation: ***Noncontrast head CT***
- A **noncontrast head CT** is the most crucial initial step in managing acute stroke symptoms because it can rapidly rule out an **intracranial hemorrhage**.
- Distinguishing between ischemic stroke and hemorrhagic stroke is critical, as the management strategies are vastly different and administering thrombolytics in the presence of hemorrhage can be fatal.
*Thrombolytics*
- **Thrombolytics** can only be administered after an **intracranial hemorrhage** has been excluded via noncontrast head CT.
- Administering thrombolytics without imaging could worsen a hemorrhagic stroke, causing significant harm or death.
*CT angiogram*
- A **CT angiogram** is used to identify large vessel occlusions in ischemic stroke and is typically performed after a noncontrast CT rules out hemorrhage.
- This imaging is crucial for determining eligibility for **endovascular thrombectomy** but is not the very first diagnostic step.
*MRI of the head*
- An **MRI of the head** is more sensitive for detecting acute ischemic changes but takes longer to perform and is often not readily available in the acute emergency setting.
- It is not the initial imaging of choice for ruling out hemorrhage due to its longer acquisition time compared to CT.
*Aspirin*
- **Aspirin** is indicated for acute ischemic stroke but should only be given after an **intracranial hemorrhage** has been ruled out.
- Like thrombolytics, aspirin could exacerbate a hemorrhagic stroke and is thus deferred until initial imaging is complete.
Urgent vs emergent conditions recognition US Medical PG Question 4: A 29-year-old man presents to the emergency department with chest pain and fatigue for the past week. The patient is homeless and his medical history is not known. His temperature is 103°F (39.4°C), blood pressure is 97/58 mmHg, pulse is 140/min, respirations are 25/min, and oxygen saturation is 95% on room air. Physical exam is notable for scars in the antecubital fossa and a murmur over the left sternal border. The patient is admitted to the intensive care unit and is treated appropriately. On day 3 of his hospital stay, the patient presents with right-sided weakness in his arm and leg and dysarthric speech. Which of the following is the most likely etiology of his current symptoms?
- A. Herpes simplex virus encephalitis
- B. Septic emboli (Correct Answer)
- C. Intracranial hemorrhage
- D. Thromboembolic stroke
- E. Bacterial meningitis
Urgent vs emergent conditions recognition Explanation: ***Septic emboli***
- The patient's history of **intravenous drug use** (inferred from antecubital scars and homelessness), fever, hypotension, tachycardia, and a new murmur strongly suggest **infective endocarditis**.
- **Septic emboli** from an infected heart valve can dislodge and travel to the brain, causing a **stroke-like presentation** with focal neurological deficits such as right-sided weakness and dysarthria.
- This is the **most specific etiology** as it identifies both the embolic mechanism AND the infectious source.
*Herpes simplex virus encephalitis*
- While encephalitis can cause focal neurological deficits, it typically presents with **altered mental status, seizures**, and a distinct pattern on MRI (temporal lobe involvement), which is not the primary presentation here.
- The context of infective endocarditis makes **embolic events** a more direct and likely cause of acute focal deficits.
*Intracranial hemorrhage*
- Intracranial hemorrhage would typically cause a **sudden onset** of neurological deficits, often accompanied by severe headache, altered consciousness, and signs of increased intracranial pressure.
- Although endocarditis can rarely lead to mycotic aneurysms that rupture, **ischemic stroke** due to emboli is far more common than hemorrhage in this setting.
*Thromboembolic stroke*
- While septic emboli do cause an embolic stroke, **"thromboembolic stroke"** is a broader, less specific term that doesn't identify the **infectious etiology**.
- The term typically refers to sterile emboli from sources like atrial fibrillation, left ventricular thrombus, or atherosclerotic plaques.
- **"Septic emboli"** is the most precise answer as it specifically indicates emboli containing infected material from the endocarditis, which has important implications for treatment and prognosis.
*Bacterial meningitis*
- Meningitis typically presents with classic symptoms like **fever, headache, nuchal rigidity**, and altered mental status.
- While it can cause neurological complications, acute focal deficits like hemiparesis and dysarthria are more characteristic of a stroke or mass lesion, not diffuse meningeal inflammation.
Urgent vs emergent conditions recognition US Medical PG Question 5: A 28-year-old man is admitted to the emergency department with a gunshot wound to the abdomen. He complains of weakness and diffuse abdominal pain. Morphine is administered and IV fluids are started by paramedics at the scene. On admission, the patient’s blood pressure is 90/60 mm Hg, heart rate is 103/min, respiratory rate is 17/min, the temperature is 36.2℃ (97.1℉), and oxygen saturation is 94% on room air. The patient is responsive but lethargic. The patient is diaphoretic and extremities are pale and cool. Lungs are clear to auscultation. Cardiac sounds are diminished. Abdominal examination shows a visible bullet entry wound in the left upper quadrant (LUQ) with no corresponding exit wound on the flanks or back. The abdomen is distended and diffusely tender with a rebound. Aspiration of the nasogastric tube reveals bloody contents. Rectal examination shows no blood. Stool guaiac is negative. Which of the following is the next best step in management?
- A. Focused assessment with sonography for trauma (FAST)
- B. Abdominal CT
- C. Exploratory laparotomy (Correct Answer)
- D. Abdominal X-ray
- E. Diagnostic peritoneal lavage
Urgent vs emergent conditions recognition Explanation: ***Exploratory laparotomy***
- The patient presents with clear signs of **hemodynamic instability** (BP 90/60 mmHg, HR 103/min, lethargy, cool extremities, diminished cardiac sounds) following a **gunshot wound to the abdomen**.
- In hemodynamically unstable trauma patients with penetrating abdominal injuries, immediate **exploratory laparotomy** is indicated to identify and control hemorrhage and repair organ damage.
*Focused assessment with sonography for trauma (FAST)*
- While FAST can detect free fluid (e.g., blood) in the abdomen, it is **not sufficient to rule out significant injury** in a hemodynamically unstable patient with a penetrating abdominal wound.
- A positive FAST in a stable patient might prompt further imaging, but in this unstable case, it would delay definitive surgical intervention.
*Abdominal CT*
- Abdominal CT is useful for evaluating intra-abdominal injuries in **hemodynamically stable** patients.
- Performing a CT on this unstable patient would delay critical surgical intervention and could lead to rapid deterioration in the scanner.
*Abdominal X-ray*
- An abdominal X-ray can sometimes identify the **location of a bullet** or **free air** under the diaphragm, but it has limited utility in assessing or quantifying intra-abdominal hemorrhage or solid organ injury.
- It is not the definitive diagnostic or therapeutic step for an unstable patient with a penetrating abdominal injury.
*Diagnostic peritoneal lavage*
- DPL is an invasive procedure that can detect intra-abdominal bleeding or perforation, but it has largely been **replaced by FAST and CT scans** in hemodynamically stable patients.
- For a hemodynamically unstable patient with a clear indication for surgery (penetrating trauma and instability), DPL would delay definitive surgical management and provides less information than direct visualization via laparotomy.
Urgent vs emergent conditions recognition US Medical PG Question 6: A 65-year-old woman comes to the physician for the evaluation of sharp, stabbing pain in the lower back for 3 weeks. The pain radiates to the back of her right leg and is worse at night. She reports decreased sensation around her buttocks and inner thighs. During the last several days, she has had trouble urinating. Three years ago, she was diagnosed with breast cancer and was treated with lumpectomy and radiation. Her only medication is anastrozole. Her temperature is 37°C (98.6°F), pulse is 80/min, respirations are 12/min, and blood pressure is 130/70 mm Hg. Neurologic examination shows 4/5 strength in the left lower extremity and 2/5 strength in her right lower extremity. Knee and ankle reflexes are 1+ on the right. The resting anal sphincter tone is normal but the squeeze tone is reduced. Which of the following is the most likely diagnosis?
- A. Anterior spinal cord syndrome
- B. Cauda equina syndrome (Correct Answer)
- C. Conus medullaris syndrome
- D. Central cord syndrome
- E. Brown-sequard syndrome
Urgent vs emergent conditions recognition Explanation: ***Cauda equina syndrome***
- The patient's presentation with **severe low back pain**, **saddle anesthesia** (decreased sensation around buttocks and inner thighs), **bladder dysfunction** (trouble urinating), and **motor weakness** in the lower extremities is highly indicative of cauda equina syndrome. This can be caused by **spinal metastases** from her breast cancer.
- The **reduced squeeze tone** of the anal sphincter, despite normal resting tone, further supports the diagnosis, indicating dysfunction of the sacral nerve roots which are compressed in cauda equina syndrome.
*Anterior spinal cord syndrome*
- This syndrome typically presents with **motor paralysis**, loss of **pain** and **temperature** sensation below the lesion, but preservation of **proprioception** and **vibration sense**.
- It does not typically cause **saddle anesthesia** or **bladder dysfunction** to the extent seen in this patient.
*Conus medullaris syndrome*
- Conus medullaris syndrome involves the lower part of the spinal cord (T12-L2) and typically presents with **symmetric motor weakness**, **early onset bladder and bowel dysfunction**, and often **perianal numbness**.
- While there is bladder dysfunction, the described **asymmetric weakness** and prominent **radicular pain** radiating down one leg are more characteristic of cauda equina syndrome, which affects nerve roots rather than the spinal cord itself.
*Central cord syndrome*
- This syndrome usually results from hyperextension injuries and leads to **greater motor impairment in the upper extremities** than in the lower extremities.
- It is often associated with a **'shawl-like' distribution** of sensory loss and does not typically present with the same severe lower extremity weakness, saddle anesthesia, or bladder dysfunction as seen in this patient.
*Brown-Sequard syndrome*
- This syndrome is characterized by **hemisection of the spinal cord**, resulting in **ipsilateral motor paralysis** and loss of **proprioception and vibration sensation** below the level of the lesion.
- It also causes **contralateral loss of pain and temperature sensation** starting a few segments below the lesion, which does not match the patient's symptoms of bilateral sensory and motor deficits with saddle anesthesia.
Urgent vs emergent conditions recognition US Medical PG Question 7: A 43-year-old woman was admitted to the hospital after a fall. When the emergency services arrived, she was unresponsive, did not open her eyes, but responded to painful stimuli. The witnesses say that she had convulsions lasting about 30 seconds when she lost consciousness after a traumatic event. On her way to the hospital, she regained consciousness. On admission, she complained of intense headaches and nausea. She opened her eyes spontaneously, was responsive but confused, and was able to follow motor commands. Her vital signs are as follows: blood pressure, 150/90 mm Hg; heart rate, 62/min; respiratory rate, 13/min; and temperature, 37.3℃ (99.1℉). There are no signs of a skull fracture. The pupils are round, equal, and poorly reactive to light. She is unable to fully abduct both eyes. Ophthalmoscopy does not show papillary edema or retinal hemorrhages. She has nuchal rigidity and a positive Kernig sign. An urgent head CT does not show any abnormalities. Which of the following is a proper investigation to perform in this patient?
- A. Lumbar puncture (Correct Answer)
- B. Angiography
- C. Sonography
- D. Brain MRI
- E. EEG
Urgent vs emergent conditions recognition Explanation: ***Lumbar puncture***
- The patient's symptoms, including **severe headache**, **nuchal rigidity**, **positive Kernig sign**, and **abnormal oculomotor findings** (poorly reactive pupils, inability to abduct eyes), despite a normal head CT, are highly suggestive of **subarachnoid hemorrhage**. A lumbar puncture is essential to look for **xanthochromia** (yellowish discoloration of CSF due to bilirubin from lysed red blood cells), which confirms the diagnosis, especially when CT is negative in the first 6-12 hours.
- The history of a "traumatic event" followed by convulsions and transient loss of consciousness, along with a "lucid interval" then renewed symptoms (headache, confusion), raises suspicion for head injury leading to hemorrhagic event. The **elevated BP and bradycardia** (Cushing's reflex components), though not fully developed, also suggest increased intracranial pressure, further warranting investigation for hemorrhage.
*Angiography*
- While angiography (CTA or conventional) is performed **after a subarachnoid hemorrhage is confirmed** to identify the source of bleeding (e.g., aneurysm), it is not the *initial* diagnostic test to *confirm* the hemorrhage itself when CT is negative.
- Doing an angiography before ruling out significant hemorrhage via LP (when CT is negative) is premature and could expose the patient to unnecessary risks without a confirmed diagnosis.
*Sonography*
- **Sonography** (ultrasound) has **no role** in the acute diagnosis of subarachnoid hemorrhage or other intracranial pathology in adults.
- It is used for imaging the brain in neonates through the open fontanelles but is ineffective through the adult skull.
*Brain MRI*
- While an **MRI is more sensitive than CT for detecting subarachnoid hemorrhage** (especially subacute hemorrhage or small bleeds missed by CT), it is generally **less readily available** in an emergency setting than CT and LP.
- In cases where CT is negative but clinical suspicion for SAH is high, **lumbar puncture is typically the next step** as it can detect early SAH via xanthochromia, which might not be immediately visible on MRI. MRI may be used later to identify causes or small bleeds not picked up by CT.
*EEG*
- An **EEG (electroencephalogram)** is used to **evaluate seizure activity** and other types of brain dysfunction related to electrical activity.
- While the patient had convulsions, the primary concern given her overall presentation (severe headache, meningeal signs, altered mental status, and cranial nerve palsies) is **subarachnoid hemorrhage**, not solely seizure. An EEG would not help diagnose the underlying cause of her acute neurological deterioration.
Urgent vs emergent conditions recognition US Medical PG Question 8: A 47-year-old male with a medical history significant for hypertension, recurrent urinary tract infections, mitral valve prolapse, and diverticulosis experiences a sudden, severe headache while watching television on his couch. He calls 911 and reports to paramedics that he feels as if "someone shot me in the back of my head." He is rushed to the emergency room. On exam, he shows no focal neurological deficits but has significant nuchal rigidity and photophobia. Of the options below, what is the most likely etiology of this man's headache?
- A. Temporal Arteritis
- B. Brain Tumor
- C. Carotid Dissection
- D. Migraine
- E. Subarachnoid Hemorrhage (Correct Answer)
Urgent vs emergent conditions recognition Explanation: ***Subarachnoid Hemorrhage***
- The sudden onset of a "thunderclap" headache, often described as the "worst headache of my life" or feeling like "someone shot me in the back of my head", is a classic presentation of **subarachnoid hemorrhage (SAH)**.
- **Nuchal rigidity** (neck stiffness) and **photophobia** are common signs of meningeal irritation due to blood in the subarachnoid space.
*Temporal Arteritis*
- Typically presents in older individuals (usually >50 years old) with headache, **scalp tenderness**, jaw claudication, and visual disturbances, often associated with elevated inflammatory markers.
- The sudden, extremely severe nature and the patient's age (47) make this less likely.
*Brain Tumor*
- Headache associated with a brain tumor usually has a more **gradual onset** and progressive worsening, often accompanied by **focal neurological deficits** or seizures.
- The acute, severe "thunderclap" nature described here is not typical for a brain tumor headache.
*Carotid Dissection*
- Carotid dissection can cause a sudden headache, often unilateral, and may be associated with **neck pain**, neurological deficits (e.g., Horner's syndrome, transient ischemic attacks, stroke symptoms), or cranial nerve palsies.
- While it can present with acute headache, the description of "worst headache of my life" and prominent nuchal rigidity without focal deficits points more strongly to SAH.
*Migraine*
- Migraines typically have a **prodrome** or a more gradual onset, often accompanied by aura, photophobia, phonophobia, and nausea; they are usually recurrent.
- While migraines can be severe, the description of a sudden, explosive headache with associated nuchal rigidity is more characteristic of a serious underlying vascular event like SAH.
Urgent vs emergent conditions recognition US Medical PG Question 9: A 53-year-old man is brought to the emergency department by his wife for the evaluation of a progressively generalized headache that started suddenly 2 hours ago. He describes the pain as 10 out of 10 in intensity. The pain radiates to the neck and is aggravated by lying down. The patient has vomited once on his way to the hospital. He had a similar headache 1 week ago that had resolved after a few hours without treatment. The patient has smoked one pack of cigarettes daily for 35 years. He does not drink alcohol or use illicit drugs. He appears lethargic. His temperature is 37.7°C (99.9°F), pulse is 82/min, respirations are 13/min, and blood pressure is 165/89 mm Hg. Pupils are equal and reactive to light and extraocular eye movements are normal. There is no weakness or sensory loss. Reflexes are 2+ throughout. Neck flexion causes worsening of the pain. Which of the following is the most appropriate next step in the management of this patient?
- A. MRI scan of the brain
- B. Electroencephalogram
- C. CT scan of the head without contrast (Correct Answer)
- D. Lumbar puncture
- E. CT angiography of the head
Urgent vs emergent conditions recognition Explanation: ***CT scan of the head without contrast***
- The patient's presentation with a **sudden-onset, severe "thunderclap" headache**, nausea/vomiting, hypertension, and neck stiffness is highly concerning for a **subarachnoid hemorrhage (SAH)**. A non-contrast CT scan of the head is the most appropriate initial imaging study to rapidly detect SAH, which appears as high-attenuation blood in the subarachnoid spaces.
- Given the urgency and life-threatening nature of SAH, a CT scan is preferred over MRI due to its **faster acquisition time** and high sensitivity in the acute setting (within 12-24 hours of symptom onset) for detecting acute blood.
*MRI scan of the brain*
- While an MRI can detect SAH, it is **less readily available** and has a **longer acquisition time** compared to CT, making it less suitable for initial evaluation of an acute, potentially life-threatening SAH.
- MRI is generally more sensitive for detecting parenchymal abnormalities and chronic blood, but **CT is superior for acute SAH** due to its speed and ability to clearly visualize acute blood.
*Electroencephalogram*
- An **EEG measures electrical activity in the brain** and is primarily used to diagnose seizure disorders or evaluate altered mental status from diffuse brain dysfunction.
- It does not provide structural information and is **not useful for diagnosing acute intracranial hemorrhage** or other structural causes of sudden severe headache.
*Lumbar puncture*
- A lumbar puncture (LP) is typically performed if the **CT scan is negative for SAH but clinical suspicion remains very high**. The presence of **xanthochromia** (yellow discoloration of CSF) due to bilirubin breakdown products of red blood cells confirms SAH.
- However, LP is an **invasive procedure** and should only be performed **after ruling out a mass effect** on CT to prevent brain herniation, especially in a patient with altered mental status and signs of increased intracranial pressure.
*CT angiography of the head*
- CT angiography is used to **visualize intracranial blood vessels** and identify the source of bleeding, such as an aneurysm, after SAH has been confirmed.
- It is an **additional diagnostic step** taken after an initial non-contrast CT confirms the presence of SAH, not the initial diagnostic test to rule out acute bleeding.
Urgent vs emergent conditions recognition US Medical PG Question 10: A 21-year-old college student is brought to the emergency department in a state of confusion. He also had one seizure approx. 45 minutes ago. He was complaining of fever and headache for the past 3 days. There was no history of nausea, vomiting, head trauma, sore throat, skin rash, or abdominal pain. Physical examination reveals: blood pressure 102/78 mm Hg, heart rate 122/min, and temperature 38.4°C (101.2°F). The patient is awake but confused and disoriented. He is sensitive to light and loud noises. Heart rate is elevated with a normal rhythm. Lungs are clear to auscultation bilaterally. The fundus examination is benign. Brudzinski’s sign is positive. What is the next best step in the management of this patient?
- A. Intensive care unit referral
- B. MRI of the brain
- C. CT scan of the brain (Correct Answer)
- D. Electroencephalography
- E. Lumbar puncture
Urgent vs emergent conditions recognition Explanation: ***CT scan of the brain***
- The patient presents with **altered mental status** (confusion, disorientation) and a **recent seizure**, which are **absolute indications for CT scan before lumbar puncture** according to IDSA guidelines.
- Even with a benign fundus examination, CT is necessary to rule out **increased intracranial pressure**, **mass lesions**, or **brain abscess** that could cause herniation during LP.
- In suspected meningitis with these risk factors, the standard approach is: **CT first → then LP if CT is safe** → empiric antibiotics if LP is delayed.
- This protects against the potentially fatal complication of **cerebral herniation** during lumbar puncture.
*Lumbar puncture*
- While lumbar puncture is **essential for diagnosing meningitis** and analyzing CSF, it must be performed safely.
- In patients with altered consciousness or seizures, **LP should be deferred until after CT** rules out contraindications.
- If LP is delayed, **empiric antibiotics** (e.g., ceftriaxone + vancomycin + acyclovir) should be started immediately after blood cultures.
*Intensive care unit referral*
- ICU referral may be appropriate after initial diagnostic workup and stabilization, or if the patient deteriorates rapidly.
- However, the **immediate next step** is to obtain neuroimaging before proceeding with LP to confirm the diagnosis.
*MRI of the brain*
- MRI provides superior detail for evaluating **encephalitis**, **brain abscess**, or other parenchymal pathology.
- However, **CT is faster and more readily available** in the emergency setting and is sufficient for ruling out LP contraindications.
- MRI may be obtained later for further characterization if needed.
*Electroencephalography*
- EEG evaluates seizure activity and can identify seizure foci or status epilepticus.
- While the patient had a seizure, the **primary concern is suspected meningitis**, which requires CSF analysis (after safe neuroimaging).
- EEG does not diagnose the underlying infectious cause and is not the immediate priority.
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