Surgical complications

Surgical complications US Medical PG Question 1: A 52-year-old man comes to the physician because of a 3-week history of a cough and hoarseness. He reports that the cough is worse when he lies down after lunch. His temperature is 37.5°C (99.5°F); the remainder of his vital signs are within normal limits. Because the physician has recently been seeing several patients with the common cold, the diagnosis of a viral upper respiratory tract infection readily comes to mind. The physician fails to consider the diagnosis of gastroesophageal reflux disease, which the patient is later found to have. Which of the following most accurately describes the cognitive bias that the physician had?

• A. Framing
• B. Anchoring
• C. Visceral
• D. Confirmation
• E. Availability (Correct Answer)

Surgical complications Explanation: ***Availability*** - The physician recently seeing several patients with the common cold led to this diagnosis readily coming to mind, demonstrating how easily recalled examples can disproportionately influence diagnosis. - This bias occurs when easily recalled instances or information (like recent cases of common cold) are used to estimate the likelihood or frequency of an event, even if other more relevant data exist. *Framing* - This bias occurs when the way information is presented (e.g., as a gain or a loss) influences a decision, rather than the intrinsic characteristics of the options themselves. - The scenario does not involve the presentation of information in different ways to sway the physician's judgment. *Anchoring* - This bias involves relying too heavily on an initial piece of information (the "anchor") when making subsequent judgments, often leading to insufficient adjustment away from that anchor. - While the physician initially considered a viral URI, the setup is more about the ease of recall influencing the decision rather than being stuck on an initial data point. *Visceral* - This is not a commonly recognized cognitive bias in the context of medical decision-making; "visceral" largely refers to emotional or intuitive feelings rather than a structured cognitive bias. - Cognitive biases describe systematic patterns of deviation from norm or rationality in judgment, not merely emotional responses. *Confirmation* - This bias involves seeking, interpreting, favoring, and recalling information in a way that confirms one's pre-existing beliefs or hypotheses. - The physician did not actively seek information to confirm the common cold diagnosis; rather, the diagnosis came to mind due to recent encounters, which aligns with availability bias.

Surgical complications US Medical PG Question 2: A 68-year-old woman presents to the hospital for an elective right hemicolectomy. She is independently mobile and does her own shopping. She has had type 2 diabetes mellitus for 20 years, essential hypertension for 15 years, and angina on exertion for 6 years. She has a 30-pack-year history of smoking. The operation was uncomplicated. On post-op day 5, she becomes confused. She has a temperature of 38.5°C (101.3°F), respiratory rate of 28/min, and oxygen saturation of 92% on 2 L of oxygen. She is tachycardic at 118/min and her blood pressure is 110/65 mm Hg. On chest auscultation, she has coarse crackles in the right lung base. Her surgical wound appears to be healing well, and her abdomen is soft and nontender. Which of the following is the most likely diagnosis?

• A. Malignant hyperthermia
• B. Drug-induced fever
• C. Multiple organ dysfunction syndrome
• D. Sepsis (Correct Answer)
• E. Non-infectious systemic inflammatory response syndrome (SIRS)

Surgical complications Explanation: ***Sepsis*** - The patient exhibits several signs of **systemic inflammatory response syndrome (SIRS)** (fever, tachycardia, tachypnea) coupled with evidence of infection (coarse crackles in the lung base suggests **pneumonia**). - The combination of **SIRS criteria** and a likely infection source in a postoperative patient strongly points to sepsis, a life-threatening organ dysfunction caused by a dysregulated host response to infection. *Malignant hyperthermia* - This is a rare, life-threatening condition typically triggered by **volatile anesthetic agents** or **succinylcholine** during surgery. - It usually presents **intraoperatively or immediately postoperatively** with rapid onset of hyperthermia, muscle rigidity, and metabolic acidosis, which is not consistent with a presentation on post-op day 5. *Drug-induced fever* - While drug-induced fever is possible, particularly in polymedicated patients, it would be a **diagnosis of exclusion** when other more likely causes of fever, such as infection, are present. - There are no specific clinical features in this case that strongly suggest a drug as the singular cause of fever and the systemic inflammatory response. *Multiple organ dysfunction syndrome* - **MODS** is the progressive failure of two or more organ systems and is often a **complication of severe sepsis or septic shock**, rather than an initial diagnosis. - While the patient is unwell, her current presentation describes a potential precursor (sepsis) rather than established multi-organ dysfunction. *Non-infectious systemic inflammatory response syndrome (SIRS)* - SIRS caused by non-infectious etiologies (e.g., pancreatitis, trauma, burns) can occur, but the presence of **localized lung crackles** and a **postoperative fever** makes an infectious etiology much more likely. - Postoperative SIRS can occur due to surgical stress, but the signs of infection (especially respiratory) shift the diagnosis towards sepsis.

Surgical complications US Medical PG Question 3: A 55-year-old woman is being managed on the surgical floor after having a total abdominal hysterectomy as a definitive treatment for endometriosis. On day 1 after the operation, the patient complains of fevers. She has no other complaints other than aches and pains from lying in bed as she has not moved since the procedure. She is currently receiving ondansetron, acetaminophen, and morphine. Her temperature is 101°F (38.3°C), blood pressure is 127/68 mmHg, pulse is 100/min, respirations are 17/min, and oxygen saturation is 94% on room air. Her abdominal exam is within normal limits and cardiopulmonary exam is only notable for mild crackles. Which of the following is the most likely etiology of this patient’s fever?

• A. Deep vein thrombosis
• B. Abscess formation
• C. Inflammatory stimulus of surgery (Correct Answer)
• D. Urinary tract infection
• E. Wound infection

Surgical complications Explanation: ***Inflammatory stimulus of surgery*** - Postoperative fever occurring within the first 24-48 hours after surgery, especially a major abdominal procedure, is most commonly due to the **systemic inflammatory response** to tissue trauma and stress from the surgery itself. - The temperature of 101°F (38.3°C) is a common reactive fever. In this timeframe, **atelectasis** (part of the inflammatory response to surgery) is the classic cause, supported by the patient's **immobility since surgery** and **mild crackles** on exam. - The patient has no other specific signs of infection, making this the most likely cause. *Deep vein thrombosis* - While DVT is a concern post-surgery, it typically presents with **leg pain, swelling, and tenderness**, not primarily as fever alone on day 1. - A fever from DVT would usually indicate a more advanced complication like pulmonary embolism, which is inconsistent with the mild crackles and stable oxygen saturation. *Abscess formation* - Abscesses usually take several days to form and present with significant fevers, localized pain, and possibly purulent drainage, not typically within the first **24 hours post-op**. - The abdominal exam is noted as within normal limits, making an abscess unlikely at this early stage. *Urinary tract infection* - UTIs are common post-op, especially with catheterization, but typically present with **dysuria, frequency, urgency**, and sometimes suprapubic pain, which are absent here. - While fever can be a symptom, the lack of urinary complaints makes it a less likely primary diagnosis on day 1. *Wound infection* - Wound infections rarely develop within the first **24-48 hours** post-surgery, as bacteria require time to proliferate and cause inflammatory signs. - Typical signs include **erythema, warmth, tenderness, and purulent drainage** at the incision site, which are not mentioned.

Surgical complications US Medical PG Question 4: A 34-year-old male is brought to the emergency department by fire and rescue following a motor vehicle accident in which the patient was an unrestrained driver. The paramedics report that the patient was struck from behind by a drunk driver. He was mentating well at the scene but complained of pain in his abdomen. The patient has no known past medical history. In the trauma bay, his temperature is 98.9°F (37.2°C), blood pressure is 86/51 mmHg, pulse is 138/min, and respirations are 18/min. The patient is somnolent but arousable to voice and pain. His lungs are clear to auscultation bilaterally. He is diffusely tender to palpation on abdominal exam with bruising over the left upper abdomen. His distal pulses are thready, and capillary refill is delayed bilaterally. Two large-bore peripheral intravenous lines are placed to bolus him with intravenous 0.9% saline. Chest radiograph shows multiple left lower rib fractures. Which of the following parameters is most likely to be seen in this patient?

• A. Increased cardiac output
• B. Increased mixed venous oxygen saturation
• C. Decreased pulmonary capillary wedge pressure (Correct Answer)
• D. Decreased systemic vascular resistance
• E. Increased right atrial pressure

Surgical complications Explanation: ***Decreased pulmonary capillary wedge pressure*** - The patient presents with classic signs of **hemorrhagic shock** (hypotension, tachycardia, somnolence, abdominal bruising, thready pulses) due to trauma, likely involving the spleen or kidney given the left upper abdominal bruising and rib fractures. - **Decreased pulmonary capillary wedge pressure (PCWP)** is expected in hypovolemic shock because it reflects left atrial and left ventricular end-diastolic pressure, which will be low due to reduced venous return and intravascular volume. *Increased cardiac output* - In **hemorrhagic shock**, the body attempts to compensate by increasing heart rate, but overall **cardiac output is typically decreased** due to profound reduction in preload (venous return) from blood loss. - While heart rate is elevated, the stroke volume is severely diminished, leading to a net decrease in cardiac output despite compensatory efforts. *Increased mixed venous oxygen saturation* - **Mixed venous oxygen saturation (SvO2)** is generally **decreased in hemorrhagic shock** due to increased oxygen extraction by tissues. - Inadequate oxygen delivery to the tissues forces them to extract more oxygen from the blood, leading to a lower SvO2. *Decreased systemic vascular resistance* - In **hemorrhagic shock**, the body activates compensatory mechanisms, including generalized **vasoconstriction**, to maintain blood pressure and prioritize blood flow to vital organs. - This leads to an **increased systemic vascular resistance (SVR)**, not decreased, as reflected by the thready distal pulses and delayed capillary refill. *Increased right atrial pressure* - **Right atrial pressure (RAP)**, representing CVP, is typically **decreased in hemorrhagic shock** due to reduced circulating blood volume. - A lower RAP indicates decreased venous return to the heart, a hallmark of hypovolemia.

Surgical complications US Medical PG Question 5: An epidemiologist is evaluating the efficacy of Noxbinle in preventing HCC deaths at the population level. A clinical trial shows that over 5 years, the mortality rate from HCC was 25% in the control group and 15% in patients treated with Noxbinle 100 mg daily. Based on this data, how many patients need to be treated with Noxbinle 100 mg to prevent, on average, one death from HCC?

• A. 20
• B. 73
• C. 10 (Correct Answer)
• D. 50
• E. 100

Surgical complications Explanation: ***10*** - The **number needed to treat (NNT)** is calculated by first finding the **absolute risk reduction (ARR)**. - **ARR** = Risk in control group - Risk in treatment group = 25% - 15% = **10%** (or 0.10). - **NNT = 1 / ARR** = 1 / 0.10 = **10 patients**. - This means that **10 patients must be treated with Noxbinle to prevent one death from HCC** over 5 years. *20* - This would result from an ARR of 5% (1/0.05 = 20), which is not supported by the data. - May arise from miscalculating the risk difference or incorrectly halving the actual ARR. *73* - This value does not correspond to any standard calculation of NNT from the given mortality rates. - May result from confusion with other epidemiological measures or calculation error. *50* - This would correspond to an ARR of 2% (1/0.02 = 50), which significantly underestimates the actual risk reduction. - Could result from incorrectly calculating the difference as a proportion rather than absolute percentage points. *100* - This would correspond to an ARR of 1% (1/0.01 = 100), grossly underestimating the treatment benefit. - May result from confusing ARR with relative risk reduction or other calculation errors.

Surgical complications Flashcard 1 of 5

Question: _____ is caused by GAS and enters through trauma openings causing infection and ultimately necrotic skin with large bullae.

Answer: Necrotizing fasciitis

Surgical complications Flashcard 2 of 5

Question: A _____ is indicated when an emergency airway is required or orotracheal / nasotracheal intubation is unsuccessful / contraindicated

Answer: cricothyrotomy

Surgical complications Flashcard 3 of 5

Question: Patients who have undergone _____ surgery can sometimes manifest with symptoms of hypoparathyroidism and hypocalcemia.

Answer: Thyroid

Surgical complications Flashcard 4 of 5

Question: Gas emboli may be iatrogenic, secondary to _____ procedures as air is pumped into the abdomen

Answer: laparoscopic

Surgical complications Flashcard 5 of 5

Question: Herniated contents may be at risk for _____, which is the inability to reduce contents back into the abdomen/pelvis

Answer: incarceration