Cost-effectiveness of minimally invasive surgery US Medical PG Practice Questions and MCQs
Practice US Medical PG questions for Cost-effectiveness of minimally invasive surgery. These multiple choice questions (MCQs) cover important concepts and help you prepare for your exams.
Cost-effectiveness of minimally invasive surgery US Medical PG Question 1: A 36-year-old woman is brought to the emergency department 20 minutes after being involved in a high-speed motor vehicle collision. On arrival, she is unconscious. Her pulse is 140/min, respirations are 12/min and shallow, and blood pressure is 76/55 mm Hg. 0.9% saline infusion is begun. A focused assessment with sonography shows blood in the left upper quadrant of the abdomen. Her hemoglobin concentration is 7.6 g/dL and hematocrit is 22%. The surgeon decided to move the patient to the operating room for an emergent explorative laparotomy. Packed red blood cell transfusion is ordered prior to surgery. However, a friend of the patient asks for the transfusion to be held as the patient is a Jehovah's Witness. The patient has no advance directive and there is no documentation showing her refusal of blood transfusions. The patient's husband and children cannot be contacted. Which of the following is the most appropriate next best step in management?
- A. Administer hydroxyethyl starch
- B. Transfusion of packed red blood cells (Correct Answer)
- C. Consult hospital ethics committee
- D. Administer high-dose iron dextran
Cost-effectiveness of minimally invasive surgery Explanation: ***Transfusion of packed red blood cells***
- This patient is in **hemorrhagic shock** (tachycardia, hypotension, low hemoglobin, and hematocrit with evidence of active bleeding), requiring emergent blood transfusion to prevent irreversible organ damage and death.
- In an **emergency setting** with an **unconscious patient** and **no documented refusal** of blood products, the principle of **presumed consent** for life-saving treatment takes precedence, especially when next of kin cannot be reached.
*Administer hydroxyethyl starch*
- **Colloids** like hydroxyethyl starch can temporarily increase intravascular volume but do not provide oxygen-carrying capacity, which is critically needed for a patient with severe anemia and hemorrhagic shock.
- While useful for volume expansion, it is **not a substitute for blood products** in severe bleeding and can have adverse effects such as kidney injury.
*Consult hospital ethics committee*
- Consulting an ethics committee is appropriate for **complex ethical dilemmas** when there is time for deliberation and the patient's life is not in immediate danger.
- In this acute, life-threatening emergency, **delaying treatment** to consult an ethics committee would jeopardize the patient's life and is not appropriate.
*Administer high-dose iron dextran*
- **Iron dextran** is used to treat iron-deficiency anemia and works by supporting red blood cell production over several days to weeks.
- It is **ineffective in acute hemorrhagic shock** where immediate restoration of oxygen-carrying capacity is required.
Cost-effectiveness of minimally invasive surgery US Medical PG Question 2: A researcher is studying whether a new knee implant is better than existing alternatives in terms of pain after knee replacement. She designs the study so that it includes all the surgeries performed at a certain hospital. Interestingly, she notices that patients who underwent surgeries on Mondays and Thursdays reported much better pain outcomes on a survey compared with those who underwent the same surgeries from the same surgeons on Tuesdays and Fridays. Upon performing further analysis, she discovers that one of the staff members who works on Mondays and Thursdays is aware of the study and tells all the patients about how wonderful the new implant is. Which of the following forms of bias does this most likely represent?
- A. Hawthorne effect
- B. Pygmalion effect (Correct Answer)
- C. Attrition bias
- D. Golem effect
Cost-effectiveness of minimally invasive surgery Explanation: ***Pygmalion effect***
- This bias occurs when higher expectations lead to an increase in performance. In this scenario, the staff member's positive reinforcement about the new implant likely instilled **higher patient expectations**, leading to better reported pain outcomes.
- The patients' belief in the implant's superiority, influenced by the staff member, acted as a **self-fulfilling prophecy**, improving their subjective pain experience.
*Hawthorne effect*
- This effect describes how individuals modify an aspect of their behavior in response to their awareness of being observed. While patients were part of a study, their improved outcomes were specifically linked to a staff member's verbal influence, not solely the act of observation.
- The improved pain outcomes stem from the **expectations created by the staff member's praise**, rather than a general awareness of being studied.
*Attrition bias*
- Attrition bias refers to systematic differences between groups in the loss of participants from a study.
- This scenario describes differences in patient outcomes based on staff influence during the study, not due to **patients dropping out differentially** between groups.
*Golem effect*
- The Golem effect is the opposite of the Pygmalion effect, where lower expectations placed upon individuals lead to poorer performance from them.
- In this case, the staff member's influence created **high expectations and positive outcomes**, not negative expectations leading to worse outcomes.
Cost-effectiveness of minimally invasive surgery US Medical PG Question 3: A 56-year-old previously healthy woman with no other past medical history is post-operative day one from an open reduction and internal fixation of a fractured right radius and ulna after a motor vehicle accident. What is one of the primary ways of preventing postoperative pneumonia in this patient?
- A. Shallow breathing exercises
- B. Incentive spirometry (Correct Answer)
- C. Outpatient oral antibiotics
- D. Hyperbaric oxygenation
- E. In-hospital intravenous antibiotics
Cost-effectiveness of minimally invasive surgery Explanation: ***Incentive spirometry***
- **Incentive spirometry** is a cornerstone of postoperative care, actively encouraging patients to take slow, deep breaths. This expands the lungs and prevents the collapse of alveoli, reducing the risk of **atelectasis** and subsequent **pneumonia**.
- Its effectiveness lies in promoting lung aeration and clearing secretions, which are crucial after anesthesia and surgery, especially in patients with reduced mobility or pain.
*Shallow breathing exercises*
- **Shallow breathing** is insufficient for adequate lung expansion and can actually contribute to **atelectasis** and the pooling of secretions in the lungs.
- Effective pulmonary hygiene requires **deep breaths** to maximize alveolar recruitment and prevent respiratory complications.
*Outpatient oral antibiotics*
- **Prophylactic antibiotics** are typically given around the time of surgery to prevent surgical site infections, not primarily to prevent postoperative pneumonia in an outpatient setting.
- Administering antibiotics without a diagnosed infection can lead to **antibiotic resistance** and is not a standard practice for preventing pneumonia unless a specific risk factor or existing infection is identified.
*Hyperbaric oxygenation*
- **Hyperbaric oxygenation** involves breathing 100% oxygen in a pressurized chamber and is used for conditions like **decompression sickness**, non-healing wounds, or severe infections.
- It is not a standard or primary method for preventing postoperative pneumonia, as its mechanism of action is unrelated to common pulmonary hygiene techniques.
*In-hospital intravenous antibiotics*
- While antibiotics can treat pneumonia, their routine, **prophylactic use** intravenously in-hospital solely for preventing postoperative pneumonia is generally unwarranted and can contribute to **antibiotic resistance**.
- Antibiotics are indicated if there is evidence of an active infection, but the primary prevention of pneumonia focuses on mechanical lung expansion and airway clearance.
Cost-effectiveness of minimally invasive surgery US Medical PG Question 4: A surgeon is interested in studying how different surgical techniques impact the healing of tendon injuries. In particular, he will compare 3 different types of suture repairs biomechanically in order to determine the maximum load before failure of the tendon 2 weeks after repair. He collects data on maximum load for 90 different repaired tendons from an animal model. Thirty tendons were repaired using each of the different suture techniques. Which of the following statistical measures is most appropriate for analyzing the results of this study?
- A. Chi-squared
- B. Wilcoxon rank sum
- C. Pearson r coefficient
- D. Student t-test
- E. ANOVA (Correct Answer)
Cost-effectiveness of minimally invasive surgery Explanation: ***ANOVA***
- **ANOVA (Analysis of Variance)** is appropriate here because it compares the means of **three or more independent groups** (the three different suture techniques) on a continuous dependent variable (maximum load before failure).
- The study has three distinct repair techniques, each with 30 tendons, making ANOVA suitable for determining if there are statistically significant differences among their mean failure loads.
*Chi-squared*
- The **Chi-squared test** is used for analyzing **categorical data** (frequencies or proportions) to determine if there is an association between two nominal variables.
- This study involves quantitative measurement (maximum load), not categorical data, making Chi-squared inappropriate.
*Wilcoxon rank sum*
- The **Wilcoxon rank sum test** (also known as Mann-Whitney U test) is a **non-parametric test** used to compare two independent groups when the data is not normally distributed or is ordinal.
- While the study has independent groups, it involves three groups, and the dependent variable is continuous, making ANOVA a more powerful and appropriate choice assuming normal distribution.
*Pearson r coefficient*
- The **Pearson r coefficient** measures the **strength and direction of a linear relationship between two continuous variables**.
- This study aims to compare means across different groups, not to determine the correlation between two continuous variables.
*Student t-test*
- The **Student t-test** is used to compare the means of **exactly two groups** (either independent or paired) on a continuous dependent variable.
- This study involves comparing three different suture techniques, not just two, making the t-test unsuitable.
Cost-effectiveness of minimally invasive surgery US Medical PG Question 5: A 27-year-old man is brought to the emergency department after a motor vehicle accident. He was the unrestrained driver in a head on collision. The patient is responding incoherently and is complaining of being in pain. He has several large lacerations and has been impaled with a piece of metal. IV access is unable to be obtained and a FAST exam is performed. His temperature is 98.2°F (36.8°C), blood pressure is 90/48 mmHg, pulse is 150/min, respirations are 13/min, and oxygen saturation is 98% on room air. Which of the following is the best next step in management?
- A. Reattempt intravenous access
- B. Obtain intraosseous access (Correct Answer)
- C. Place a central line
- D. Administer oral fluids
- E. Exploratory laparotomy
Cost-effectiveness of minimally invasive surgery Explanation: ***Obtain intraosseous access***
- The patient is in **hypotensive shock** (BP 90/48 mmHg, HR 150/min) after a severe trauma, and **IV access cannot be obtained**. **Intraosseous (IO) access** provides a rapid and reliable route for fluid and medication administration in emergent situations when peripheral IV access is difficult or impossible.
- While central line placement is also a viable option, **IO access is generally faster and easier to establish** in an emergency setting by a wide range of providers, making it the **best initial step** when peripheral IV fails.
*Reattempt intravenous access*
- Although obtaining IV access is critical, the question states that it "is unable to be obtained," implying initial attempts have failed or are proving too difficult/time-consuming given the patient's critical state.
- Persisting with repeated attempts risks significant delay in resuscitation, which is detrimental for a patient in shock.
*Place a central line*
- A central line provides reliable access for fluid and medication, but its placement is generally **more time-consuming** and technically challenging than IO access, especially in an agitated, unstable patient in a chaotic emergency setting.
- The immediate priority is rapid access for fluids to address the patient's shock, for which IO is superior in terms of speed of establishment.
*Administer oral fluids*
- The patient is **unstable**, **incoherently responding**, and likely has significant internal injuries given the mechanism of injury (head-on collision, impalement).
- Oral fluids would be **ineffective** and potentially dangerous (risk of aspiration) in this critical, hemodynamically unstable patient who requires immediate intravenous fluid resuscitation.
*Exploratory laparotomy*
- While the patient likely has significant internal injuries requiring surgical intervention (impalement, hypovolemic shock), an **exploratory laparotomy** is a definitive treatment step, not the *best next step in management* for immediate resuscitation.
- **Hemodynamic stabilization** with fluid resuscitation must occur *before* or *simultaneously with* definitive surgical intervention to improve survival chances.
Cost-effectiveness of minimally invasive surgery US Medical PG Question 6: Two hours after admission to the intensive care unit, a 56-year-old man with necrotizing pancreatitis develops profound hypotension. His blood pressure is 80/50 mm Hg and he is started on vasopressors. A central venous access line is placed. Which of the following is most likely to decrease the risk of complications from this procedure?
- A. Placement of the central venous line in the femoral vein
- B. Replacement of the central venous line every 7-10 days
- C. Initiation of anticoagulation after placement
- D. Preparation of the skin with chlorhexidine and alcohol (Correct Answer)
- E. Initiation of periprocedural systemic antibiotic prophylaxis
Cost-effectiveness of minimally invasive surgery Explanation: ***Preparation of the skin with chlorhexidine and alcohol***
- **Chlorhexidine** with alcohol is the most effective skin antiseptic for preventing **catheter-related bloodstream infections (CRBSIs)** by significantly reducing skin microbial counts.
- Proper skin preparation is a cornerstone of preventing **infectious complications** associated with central venous catheter insertion.
*Placement of the central venous line in the femoral vein*
- The femoral site is generally associated with a **higher risk of infection** and **deep venous thrombosis** compared to subclavian or internal jugular sites in adult patients.
- Femoral access is often reserved for situations where other sites are inaccessible or contraindicated, due to its **less favorable complication profile**.
*Replacement of the central venous line every 7-10 days*
- Routine replacement of central venous lines at fixed intervals, without clinical indication, has **not been shown to reduce infection rates**.
- This practice can actually **increase the risk** of mechanical complications and introduce new opportunities for infection with each procedure.
*Initiation of anticoagulation after placement*
- Routine systemic **anticoagulation** after central venous line placement is generally **not recommended** due to an increased risk of **bleeding complications**.
- Anticoagulation is typically reserved for specific indications such as documented **catheter-related thrombosis**.
*Initiation of periprocedural systemic antibiotic prophylaxis*
- Routine **systemic antibiotic prophylaxis** is **not recommended** for central venous catheter insertion as it promotes **antibiotic resistance** without significantly reducing CRBSIs.
- Strict adherence to **aseptic technique** and proper skin antisepsis are more effective for preventing infections.
Cost-effectiveness of minimally invasive surgery US Medical PG Question 7: A 63-year-old woman is brought to the emergency department because of severe abdominal pain and vomiting for 3 hours. She had previous episodes of abdominal pain that lasted for 10–15 minutes and resolved with antacids. She lives with her daughter and grandchildren. She divorced her husband last year. She is alert and oriented. Her temperature is 37.3°C (99.1°F), pulse is 134/min, and blood pressure is 90/70 mm Hg. The abdomen is rigid and diffusely tender. Guarding and rebound tenderness are present. Rectal examination shows a collapsed rectum. Infusion of 0.9% saline is begun and a CT of the abdomen shows intestinal perforation. The surgeon discusses the need for emergent exploratory laparotomy with the patient and she agrees to it. Written informed consent is obtained. While in the holding area awaiting emergent transport to the operating room, she calls for the surgeon and informs him that she no longer wants the surgery. He explains the risks of not performing the surgery to her and she indicates she understands but is adamant about not proceeding with surgery. Which of the following is the most appropriate next step in management?
- A. Consult hospital ethics committee
- B. Obtain consent from the patient's daughter
- C. Obtain consent from the patient's ex-husband
- D. Continue with emergency life-saving surgery
- E. Cancel the surgery (Correct Answer)
Cost-effectiveness of minimally invasive surgery Explanation: ***Cancel the surgery***
- The patient is **alert and oriented** and has indicated she understands the risks of refusing surgery, demonstrating **decision-making capacity**. An adult with intact capacity has the right to refuse medical treatment, even if it is life-saving.
- While the decision may seem medically unwise, **patient autonomy** is a fundamental ethical principle that must be respected once capacity is confirmed.
*Consult hospital ethics committee*
- An ethics committee consultation is typically reserved for situations where there is **uncertainty about a patient's capacity**, a conflict among healthcare providers, or a difficult ethical dilemma where principles of patient care are in clear conflict.
- In this case, the patient's capacity seems clear, and her refusal is unequivocal.
*Obtain consent from the patient's daughter*
- The patient's daughter cannot provide consent for her mother if the mother is **competent and able to make her own decisions**. **Surrogate decision-makers** are only legally authorized when the patient lacks capacity.
- The patient's expressed wishes directly override any potential preferences of her next-of-kin.
*Obtain consent from the patient's ex-husband*
- As the patient is divorced, her ex-husband has **no legal standing** to make medical decisions on her behalf.
- Even if they were still married, a spouse can only act as a surrogate if the patient lacks decision-making capacity.
*Continue with emergency life-saving surgery*
- Performing surgery against a **competent patient's explicit refusal** would be an act of **battery** and a violation of her **autonomy**.
- Even in life-threatening situations, a patient with capacity has the right to refuse treatment.
Cost-effectiveness of minimally invasive surgery US Medical PG Question 8: A researcher is trying to determine whether a newly discovered substance X can be useful in promoting wound healing after surgery. She conducts this study by enrolling the next 100 patients that will be undergoing this surgery and separating them into 2 groups. She decides which patient will be in which group by using a random number generator. Subsequently, she prepares 1 set of syringes with the novel substance X and 1 set of syringes with a saline control. Both of these sets of syringes are unlabeled and the substances inside cannot be distinguished. She gives the surgeon performing the surgery 1 of the syringes and does not inform him nor the patient which syringe was used. After the study is complete, she analyzes all the data that was collected and performs statistical analysis. This study most likely provides which level of evidence for use of substance X?
- A. Level 3
- B. Level 1 (Correct Answer)
- C. Level 4
- D. Level 5
- E. Level 2
Cost-effectiveness of minimally invasive surgery Explanation: ***Level 1***
- The study design described is a **randomized controlled trial (RCT)**, which is considered the **highest level of evidence (Level 1)** in the hierarchy of medical evidence.
- Key features like **randomization**, **control group**, and **blinding (double-blind)** help minimize bias and strengthen the validity of the findings.
*Level 2*
- Level 2 evidence typically comprises **well-designed controlled trials without randomization** (non-randomized controlled trials) or **high-quality cohort studies**.
- While strong, they do not possess the same level of internal validity as randomized controlled trials.
*Level 3*
- Level 3 evidence typically includes **case-control studies** or **cohort studies**, which are observational designs and carry a higher risk of bias compared to RCTs.
- These studies generally do not involve randomization or intervention assignment by the researchers.
*Level 4*
- Level 4 evidence is usually derived from **case series** or **poor quality cohort and case-control studies**.
- These studies provide descriptive information or investigate associations without strong control for confounding factors.
*Level 5*
- Level 5 evidence is the **lowest level of evidence**, consisting of **expert opinion** or **animal research/bench research**.
- This level lacks human clinical data or systematic investigative rigor needed for higher evidence levels.
Cost-effectiveness of minimally invasive surgery US Medical PG Question 9: A 23-year-old man comes to the emergency department because of a 2-day history of painful swelling of the right hand. There is no associated recent trauma. Physical examination shows a 3 × 3-cm area of induration that is fluctuant and warm to the touch, consistent with an abscess. The patient consents to incision and drainage of the abscess in the emergency department. Following evaluation of the patient's allergy status, a short-acting, local anesthetic drug is administered via subcutaneous infiltration. Which of the following local anesthetics would provide the shortest duration of analgesia?
- A. Etidocaine
- B. Ropivacaine
- C. Chloroprocaine (Correct Answer)
- D. Mepivacaine
- E. Lidocaine
Cost-effectiveness of minimally invasive surgery Explanation: ***Chloroprocaine***
- **Chloroprocaine** is an **ester-type** local anesthetic, which are rapidly metabolized by plasma cholinesterases, resulting in a **short duration of action**.
- Its rapid metabolism makes it suitable for procedures requiring **brief analgesia** and a quick return to normal sensation.
*Etidocaine*
- **Etidocaine** is an **amide-type** local anesthetic known for its **long duration of action** due to its high lipid solubility and protein binding.
- It would provide analgesia for a significantly longer period than the brief procedure indicated.
*Ropivacaine*
- **Ropivacaine** is an **amide-type** local anesthetic with a **long duration of action**, commonly used for regional anesthesia and continuous infusions.
- It has a slower onset but prolonged effect, making it unsuitable for the shortest duration requirement.
*Mepivacaine*
- **Mepivacaine** is an **amide-type** local anesthetic with a **moderate duration of action**, longer than chloroprocaine but shorter than ropivacaine or bupivacaine.
- Its duration is not the shortest among the options provided, as ester-type anesthetics are generally shorter-acting.
*Lidocaine*
- **Lidocaine** is an **amide-type** local anesthetic with an **intermediate duration of action**, making it one of the most commonly used.
- While relatively short-acting compared to other amides, it is still longer than chloroprocaine due to its different metabolism.
Cost-effectiveness of minimally invasive surgery US Medical PG Question 10: A 14-year-old girl presents to the emergency room complaining of abdominal pain. She was watching a movie 3 hours prior to presentation when she developed severe non-radiating right lower quadrant pain. The pain has worsened since it started. She also had non-bloody non-bilious emesis 1 hour ago and continues to feel nauseated. Her temperature is 101°F (38.3°C), blood pressure is 130/90 mmHg, pulse is 110/min, and respirations are 22/min. On exam, she has rebound tenderness at McBurney point and a positive Rovsing sign. She is stabilized with intravenous fluids and pain medication and is taken to the operating room to undergo a laparoscopic appendectomy. While in the operating room, the circulating nurse leads the surgical team in a time out to ensure that introductions are made, the patient’s name and date of birth are correct, antibiotics have been given, and the surgical site is marked appropriately. This process is an example of which of the following human factor engineering elements?
- A. Forcing function
- B. Safety culture
- C. Simplification
- D. Standardization (Correct Answer)
- E. Resilience engineering
Cost-effectiveness of minimally invasive surgery Explanation: ***Standardization***
- The surgical **time-out** is a prime example of **standardization** in healthcare, as it involves a prescribed, uniform procedure followed in every surgery to enhance safety.
- It ensures critical safety checks—like patient identification, site marking, and antibiotic administration—are consistently performed, thus reducing variability and the potential for errors.
*Forcing function*
- A **forcing function** is a design element that makes it impossible to commit an error, such as a specific connector shape that prevents incorrect device attachment.
- The time-out, while a critical safeguard, still relies on human compliance and does not physically prevent an error from occurring if the steps are not followed.
*Safety culture*
- **Safety culture** refers to the shared beliefs, values, and attitudes that employees have about safety within an organization.
- While a time-out contributes to a strong safety culture, it is a specific process or tool, not the overarching culture itself.
*Simplification*
- **Simplification** aims to reduce complexity in a process to minimize cognitive load and potential for error.
- The time-out adds a structured step rather than simplifying an existing process; its purpose is to ensure all necessary checks are systematically completed.
*Resilience engineering*
- **Resilience engineering** focuses on an organization's ability to anticipate, cope with, and recover from failures, maintaining stability in the face of disruptions.
- While the time-out promotes safety, it primarily addresses error prevention rather than the broader organizational capacity to adapt and recover from system failures.
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