Preoperative and Postoperative Care Practice Questions

Q: After an operation on the femur, chest X-ray shows widespread mottling throughout the lung field like a snowstorm. It is diagnostic of

Fat embolism. ***Fat embolism*** - A **snowstorm appearance** or **diffuse intraparenchymal opacities** on a chest X-ray, along with a history of **long bone fracture** (like the femur), is highly characteristic of fat embolism syndrome. - Fat embolism occurs when fat droplets enter the bloodstream after trauma to fat-containing tissues, leading to lung injury and respiratory distress. *Atelectasis* - Refers to the **collapse of lung tissue**, often appearing as an area of increased opacification with **volume loss** on X-ray, which is different from a "snowstorm" pattern. - It usually results from airway obstruction or hypoventilation, not typically associated with widespread mottling. *Shock lung* - This is an older term often used to describe **Acute Respiratory Distress Syndrome (ARDS)**, which presents with diffuse bilateral infiltrates. - While ARDS can be a complication of severe trauma or systemic inflammatory response, the "snowstorm" pattern in the context of a recent femur operation is more specific to fat embolism. *Bronchopneumonia* - Typically presents with **patchy infiltrates** that may be bilateral but are usually more consolidated and localized to specific areas due to inflammation and infection in the bronchioles and alveoli. - It would also likely be accompanied by symptoms of infection, such as fever and productive cough, which are not mentioned here.

Q: Which of the following is the LEAST significant risk factor for postoperative pulmonary complications?

Age > 60 years. ***Age > 60 years*** - While age is a factor, it is generally considered **less significant** than other comorbid conditions or surgical factors in predicting postoperative pulmonary complications. - Pulmonary function naturally declines with age, but healthy elderly individuals may still tolerate surgery well if other risk factors are controlled. *ASA class 3 and 4 patients* - Patients classified as **ASA (American Society of Anesthesiologists) 3 or 4** have severe systemic disease or life-threatening systemic disease, respectively. - This significantly increases their risk of **postoperative pulmonary complications** due to their underlying health issues. *Longer surgeries >2 hr* - **Prolonged duration of surgery** (typically defined as >2-3 hours) is a significant independent risk factor for pulmonary complications. - This is due to longer periods of **immobility**, ventilation, and exposure to anesthetics, contributing to atelectasis and pneumonia risk. *Upper Abdominal surgery* - **Upper abdominal surgery** is one of the highest risk categories for postoperative pulmonary complications. - Incisions in this area can cause *diaphragmatic dysfunction*, pain leading to shallow breathing, and impaired cough reflex.

Q: A key clinical finding in post-operative ileus is:

No intestinal sounds heard. ***No intestinal sounds heard*** - Postoperative ileus is characterized by a temporary arrest of **bowel peristalsis**, leading to absent or markedly decreased bowel sounds upon auscultation. - This lack of sounds is a key clinical indicator of the gut's inability to propel contents normally. *Is due to hypernatremia* - Postoperative ileus is primarily caused by multifactorial physiologic responses to surgery, including **inflammation**, **opioid use**, and **sympathetic nervous system overactivity**, not hypernatremia. - While electrolyte imbalances can contribute to gut dysmotility, hypernatremia is not the direct or primary cause of paralytic ileus. *Intestinal peristalsis never becomes normal again* - Postoperative ileus is typically a **self-limiting condition** where intestinal peristalsis eventually returns to normal. - While it can sometimes be prolonged or recurrent, it does not imply a permanent loss of intestinal function. *Begins 2-3 days post-operatively* - Postoperative ileus typically begins **immediately after surgery** and usually resolves within **2 to 3 days**, though its duration can vary depending on the surgical procedure and individual patient factors. - Its onset is directly linked to the surgical insult, not a delayed presentation.

Q: What is the most common cause of hyponatremia in surgical practice?

Fluid shifts in small intestinal obstruction. ***Fluid shifts in small intestinal obstruction*** - In **small intestinal obstruction**, fluid and electrolytes accumulate in the **dilated bowel loops**, a phenomenon known as "third spacing." - This leads to **intravascular volume depletion** and subsequent release of **antidiuretic hormone (ADH)**, causing water retention and dilutional hyponatremia. *Electrolyte loss due to duodenal fistula* - While a **duodenal fistula** can cause significant electrolyte loss, leading to hyponatremia, it is a less common clinical scenario compared to **small bowel obstruction**. - The fluid loss in a duodenal fistula is generally **hypotonic**, meaning it contains less sodium than plasma, contributing to hyponatremia. *Electrolyte loss due to pancreatic fistula* - A **pancreatic fistula** can lead to significant fluid and electrolyte loss, particularly of bicarbonate and potassium, but direct sodium loss is usually not as prominent as in small bowel obstruction. - While it can contribute to **dehydration**, it's a less common cause of hyponatremia in surgical patients than the widespread fluid shifts in obstruction. *Intussusception causing bowel obstruction* - **Intussusception** is a cause of bowel obstruction, and it leads to hyponatremia through the same mechanism of **fluid shifts** and third-spacing. - However, "fluid shifts in small intestinal obstruction" is a broader, more encompassing description of the most common cause, of which intussusception is one specific etiology.

Q: Postoperative third-space accumulation should be managed by intravenous fluid with

Normal saline. ***Normal saline*** - **Third-space accumulation** leads to fluid shifts from the intravascular space to the interstitial space, commonly seen after trauma or surgery, resulting in **hypovolemia**. - **Isotonic solutions** like normal saline help replenish the lost intravascular volume and maintain blood pressure without shifting more fluid into the third space. *Albumin* - While albumin can increase oncotic pressure and draw fluid back into the intravascular space, it is typically reserved for cases of **severe hypoalbuminemia** or when crystalloids alone are insufficient. - Using albumin in the setting of acute third-space loss without clear indications of hypoalbuminemia may not be the initial or most appropriate intervention. *Fluid restriction* - **Fluid restriction** would worsen the patient's hypovolemia as third-space losses deplete the effective circulating volume of the patient. - This approach is appropriate for conditions like **heart failure** or **SIADH**, where there is true fluid excess or impaired excretion, not for hypovolemic states due to fluid shifts. *Dextrose in water* - Dextrose in water is a **hypotonic solution** that would rapidly distribute into the intracellular and interstitial compartments and may contribute to worsening edema in the third space. - It does not effectively expand intravascular volume and can lead to **hyponatremia** if administered in large quantities.

Q: Early movement following surgery for ankylosis is

Desirable. ***Desirable*** - Early movement following surgery for **ankylosis** is crucial for preventing **re-ankylosis** and promoting the formation of a **neocartilage-like layer**. - It helps maintain joint mobility, reduce stiffness, and improves long-term functional outcomes after procedures like **arthroplasty**. *Harmful* - Delays in movement can lead to increased fibrous tissue formation, limiting the newly created joint's mobility and potentially causing **re-ankylosis**. - Prolonged immobilization after joint surgery can also lead to muscle atrophy, contractures, and impaired circulation, hindering recovery. *Indicated only when ankylosis is one sided* - The principle of early movement applies to both **unilateral** and **bilateral ankylosis** to prevent recurrence and improve range of motion in the affected joint(s). - Focusing solely on unilateral cases overlooks the functional benefits of early mobilization for all patients undergoing such surgery. *Unimportant* - Early movement is a **critical component** of postoperative recovery, as it directly impacts the success of the surgical intervention by maintaining joint space and flexibility. - Neglecting early motion can compromise the surgical outcome, increasing the risk of stiffness, pain, and the need for further interventions.

Q: Most common cause of postoperative renal failure:

Decreased renal perfusion. **Decreased renal perfusion** - **Hypovolemia** and **hypotension** during or after surgery are frequent causes of reduced blood flow to the kidneys, leading to **ischemic injury**. - This inadequate perfusion results in **acute tubular necrosis (ATN)**, which is the most common intrinsic cause of postoperative acute renal failure. - Accounts for the majority (50-80%) of postoperative acute kidney injury cases. *Toxicity of anesthetic drugs* - While some anesthetic agents, particularly older ones, could be nephrotoxic, modern anesthetics are generally **well-tolerated** by the kidneys and rarely cause direct renal failure. - **Nephrotoxicity** from anesthetic drugs is an uncommon cause compared to the widespread issue of inadequate renal perfusion during surgical stress. *Toxicity of antibiotics* - Certain antibiotics, such as **aminoglycosides** (e.g., gentamicin) and **vancomycin**, are known to be nephrotoxic. However, their use is often monitored, and renal failure due to antibiotic toxicity is less common and often preventable compared to hypovolemia. - **Antibiotic-induced nephrotoxicity** typically presents with ATN but is not the most frequent cause in the general postoperative population. *None of the options* - This option is incorrect because **decreased renal perfusion** is, in fact, a widely recognized and leading cause of postoperative renal failure.

Q: When do we have to start antibiotics to prevent post-operative infection?

30-60 minutes before incision (up to 24 hours post-op). ***30-60 minutes before incision (up to 24 hours post-op)*** - Surgical antibiotic prophylaxis (SAP) should be administered **30-60 minutes before surgical incision** to ensure adequate tissue and serum concentrations at the time of incision. - This timing allows optimal drug distribution to surgical tissues, which is crucial for preventing surgical site infections (SSIs). - For most clean and clean-contaminated surgeries, prophylaxis should be limited to a **single dose** or continued for **maximum 24 hours post-operatively** as per WHO and CDC guidelines. - Prolonged post-operative antibiotics beyond 24 hours do **not** reduce infection rates and increase the risk of **antibiotic resistance** and **adverse effects**. *1 week before surgery* - Administering antibiotics this far in advance is **unnecessary** and **ineffective** for surgical prophylaxis. - It increases the risk of **antibiotic resistance** and does not guarantee adequate drug levels at the time of incision. - Pre-operative antibiotic use should be avoided unless treating an active infection. *2 days before surgery* - This timeframe is too early to achieve prophylactic benefit during the surgical procedure. - Prolonged pre-operative use promotes **bacterial resistance** without providing additional protection. - Drug levels will not be optimal at the time of incision due to metabolism and excretion. *After surgery* - Starting antibiotics **after surgical incision** is **too late** for prophylaxis as contamination has already occurred. - Post-operative initiation is considered **therapeutic treatment** for established infection, not prevention. - The critical window for prophylaxis is the period from skin incision to wound closure.

Question 1

After an operation on the femur, chest X-ray shows widespread mottling throughout the lung field like a snowstorm. It is diagnostic of

Accepted Answer

Fat embolism

Answer

Atelectasis

Answer

Shock lung

Answer

Bronchopneumonia

Question 2

Which of the following is the LEAST significant risk factor for postoperative pulmonary complications?

Accepted Answer

Age > 60 years

Answer

ASA class 3 and 4 patients

Answer

Longer surgeries >2 hr

Answer

Upper Abdominal surgery

Question 3

A key clinical finding in post-operative ileus is:

Accepted Answer

No intestinal sounds heard

Answer

Is due to hypernatremia

Answer

Intestinal peristalsis never becomes normal again

Answer

Begins 2-3 days post-operatively

Question 4

What is the most common cause of hyponatremia in surgical practice?

Accepted Answer

Fluid shifts in small intestinal obstruction

Answer

Electrolyte loss due to duodenal fistula

Answer

Electrolyte loss due to pancreatic fistula

Answer

Intussusception causing bowel obstruction

Question 5

Postoperative third-space accumulation should be managed by intravenous fluid with

Accepted Answer

Normal saline

Answer

Albumin

Answer

Fluid restriction

Answer

Dextrose in water

Question 6

Which of the following is true about the immediate postoperative period in a young patient with previously normal lungs having upper abdominal surgery?

Accepted Answer

Arterial oxygen tension will typically be reduced by an average of 10 mm Hg when breathing room air

Answer

Diffusion hypoxia is the major determinant of arterial hypoxaemia

Answer

The CXR will typically reveal no abnormalities

Answer

Arterial oxygen tension will normalize after 15 minutes

Question 7

Early movement following surgery for ankylosis is

Accepted Answer

Desirable

Answer

Harmful

Answer

Indicated only when ankylosis is one sided

Answer

Unimportant

Question 8

Most common cause of postoperative renal failure:

Accepted Answer

Decreased renal perfusion

Answer

Toxicity of anesthetic drugs

Answer

Toxicity of antibiotics

Answer

None of the options

Question 9

When do we have to start antibiotics to prevent post-operative infection?

Accepted Answer

30-60 minutes before incision (up to 24 hours post-op)

Answer

1 week before surgery

Answer

2 days before surgery

Answer

After surgery

Question 10

A patient presents in coma for 20 days, what will be the best way to give him nutrition?

Accepted Answer

Ryle's tube feeding

Answer

Feeding via jejunostomy

Answer

Parenteral nutrition

Answer

Oral feeding

Preoperative and Postoperative Care — MCQs

Preoperative and Postoperative Care — MCQs

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