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Infection, Pharmacology & VTE MCQs

Practice Set 16 of 68

This practice set contains high-yield board review questions covering key concepts in Infection, Pharmacology & VTE. Each clinical scenario is designed to test your diagnostic and management skills relevant to this subspecialty.

Question 301

Topic: Infection, Pharmacology & VTE

A patient undergoing tibial lengthening with a circular external fixator presents with erythema, pain, and serous drainage at a proximal half-pin site. The pin remains rigidly fixed in the bone. According to standard protocols (e.g., Checketts-Burns), what is the most appropriate initial management?

. Immediate removal of the pin and re-insertion at a different site
. Intravenous vancomycin and surgical debridement
. Oral antibiotics and aggressive local pin site care
. Cessation of distraction until the erythema resolves
. Observation only, as this is a normal reaction to tension

Correct Answer & Explanation

. Oral antibiotics and aggressive local pin site care

Explanation

Superficial pin tract infections with a stable pin (Checketts-Burns grades 1-3) are best managed with oral antibiotics and improved local pin care. Pin removal is reserved for loose pins or deep osteomyelitis.

Question 302

Topic: Infection, Pharmacology & VTE

A 70-year-old male with poorly controlled diabetes presents with a chronic paronychia of his great toe, which has been present for several months. He has significant pain, erythema, and swelling, and plain radiographs show cortical irregularity and periosteal reaction of the distal phalanx. Which of the following is the most appropriate initial imaging study to confirm the suspected diagnosis?

. A. Magnetic Resonance Imaging (MRI)
. B. Computed Tomography (CT) scan
. C. Plain radiographs (X-rays)
. D. Ultrasound
. E. Bone scintigraphy

Correct Answer & Explanation

. C. Plain radiographs (X-rays)

Explanation

Correct Answer: CThe patient's history of chronic paronychia, poorly controlled diabetes (a risk factor for osteomyelitis), and the clinical signs of pain, erythema, and swelling, combined with the suspicion of bone involvement, make plain radiographs (X-rays) the most appropriate initial imaging study. X-rays are readily available, inexpensive, and can effectively demonstrate signs of osteomyelitis such as cortical irregularity, periosteal reaction, and bone erosion, especially in chronic infections. The question states that plain radiographs 'show cortical irregularity and periosteal reaction,' indicating that X-rays have already provided diagnostic information and are the correct initial step for suspected osteomyelitis.Incorrect Options:A. Magnetic Resonance Imaging (MRI):MRI is highly sensitive for osteomyelitis and can detect early changes not visible on X-rays. However, it is a more expensive and less accessible study, typically reserved for cases where X-rays are equivocal or when the extent of soft tissue involvement needs to be precisely delineated. It is not theinitialimaging study when osteomyelitis is suspected.B. Computed Tomography (CT) scan:CT scans are excellent for evaluating cortical bone detail and complex fractures but are less sensitive than MRI for early osteomyelitis and expose the patient to higher radiation. It is not the initial imaging study for suspected osteomyelitis.D. Ultrasound:Ultrasound can be useful for identifying and localizing fluid collections (abscesses) in soft tissues but is not the primary imaging modality for diagnosing osteomyelitis, although it can sometimes show periosteosteal fluid or cortical irregularities.E. Bone scintigraphy:Bone scintigraphy (bone scan) is very sensitive for detecting increased bone turnover associated with infection but lacks specificity and anatomical detail. It is often used when osteomyelitis is suspected but X-rays are negative, or to assess multifocal involvement, but it is not the initial imaging study.

Question 303

Topic: Infection, Pharmacology & VTE
An 82-year-old male presents with acute onset of severe pain, swelling, and erythema in his right dominant hand, primarily affecting the MCP and PIP joints. He has a history of hypertension, renal insufficiency (eGFR 45 mL/min/1.73m2), and takes a thiazide diuretic. He denies any recent trauma or fever. Physical examination reveals warm, exquisitely tender, swollen joints with overlying shiny, erythematous skin. There are also several firm, non-tender subcutaneous nodules on the dorsal aspect of his hand and forearm, which he states have been present for years. Given the high suspicion for an acute gout flare in the setting of chronic tophaceous disease, an arthrocentesis is performed on the most inflamed MCP joint. The synovial fluid analysis is crucial for definitive diagnosis. Which of the following findings, as depicted in the image, is considered the gold standard for confirming the diagnosis of gout?
. A. Elevated serum uric acid (SUA) level of 9.5 mg/dL
. B. Presence of a 'double contour sign' on musculoskeletal ultrasound
. C. Identification of negatively birefringent, needle-shaped crystals under polarized light microscopy
. D. Radiographic evidence of 'punched-out' erosions with sclerotic margins
. E. Synovial fluid white blood cell count of 60,000 cells/mm³ with 90% neutrophils

Correct Answer & Explanation

. C. Identification of negatively birefringent, needle-shaped crystals under polarized light microscopy

Explanation

The definitive diagnostic test for gout is the identification of negatively birefringent, needle-shaped monosodium urate (MSU) crystals under polarized light microscopy in synovial fluid. This finding confirms the presence of MSU crystals, which are pathognomonic for gout.

Question 304

Topic: Infection, Pharmacology & VTE

A 70-year-old patient with a known history of severe tophaceous gout is scheduled for surgical debulking of a large, symptomatic tophus on the dorsal aspect of his wrist that is causing significant functional impairment. He is currently experiencing an acute gout flare in his knee, with severe pain and swelling, and his serum uric acid (SUA) is 11 mg/dL. He also has a history of poorly controlled diabetes and is on warfarin for atrial fibrillation. Which of the following factors represents the MOST significant contraindication to proceeding with elective surgical intervention at this time?

. A. History of poorly controlled diabetes
. B. Use of warfarin for atrial fibrillation
. C. Acute gout flare and uncontrolled hyperuricemia
. D. Age of the patient (70 years old)
. E. Location of the tophus on the dorsal wrist

Correct Answer & Explanation

. C. Acute gout flare and uncontrolled hyperuricemia

Explanation

Correct Answer: CThe teaching case explicitly lists 'Acute Gout Flare' and 'Uncontrolled Hyperuricemia' as contraindications for surgical intervention. 'Surgical intervention is generally contraindicated during an acute inflammatory flare. Surgery can exacerbate the inflammatory response and potentially trigger a new flare. Medical management (NSAIDs, colchicine, corticosteroids) should be optimized to quiescent the inflammation before elective surgery.' Additionally, 'elective surgical intervention should ideally be deferred until serum uric acid (SUA) levels are adequately controlled... High SUA levels increase the risk of post-operative flares and continued crystal deposition.' The patient's acute knee flare and SUA of 11 mg/dL clearly fall under these contraindications.Option A is incorrect:While poorly controlled diabetes is a significant medical comorbidity that increases surgical risk, it is listed as a 'Significant Medical Comorbidity' that requires thorough pre-operative workup and risk-benefit analysis, rather than an absolute contraindication that would immediately halt an elective procedure if other factors were optimized.Option B is incorrect:Warfarin use indicates a coagulopathy, which is a contraindication if uncorrected, due to increased risk of hematoma. However, coagulopathies can often be managed pre-operatively (e.g., bridging therapy) to mitigate risk. The acute flare and uncontrolled hyperuricemia are more direct and absolute contraindications for elective surgery in this context.Option D is incorrect:While advanced age (70 years old) is associated with increased comorbidities and surgical risk, it is not an absolute contraindication in itself. Many elderly patients undergo successful elective surgeries after appropriate medical clearance.Option E is incorrect:The location of the tophus on the dorsal wrist does not represent a contraindication to surgery; rather, it is the site of the pathology requiring intervention.

Question 305

Topic: Infection, Pharmacology & VTE

A 78-year-old female with a history of chronic tophaceous gout in her hands undergoes surgical debulking of a large tophus on her left middle finger. The procedure is uneventful. Post-operatively, the patient is placed in a protective splint. During the rehabilitation phase, the hand therapist emphasizes early and aggressive mobilization. Which of the following is the MOST critical aspect of long-term post-operative management to prevent recurrence of tophi and progressive joint destruction?

. A. Prolonged immobilization to protect the surgical site
. B. High-dose NSAIDs for pain management
. C. Strict adherence to urate-lowering therapy (ULT)
. D. Aggressive passive range of motion exercises immediately post-op
. E. Surgical revision for any residual tophaceous material

Correct Answer & Explanation

. C. Strict adherence to urate-lowering therapy (ULT)

Explanation

Correct Answer: CThe teaching case explicitly states under 'Advanced Phase' of rehabilitation: 'Medical Management Reinforcement: Crucial to emphasize continued adherence to urate-lowering therapy and regular follow-up with the rheumatologist to prevent future flares and crystal deposition. This is paramount to surgical success and long-term joint health.' ULT is the cornerstone of preventing recurrence and progression of gout.Option A is incorrect:While initial protection with a splint is necessary, prolonged immobilization is a risk factor for joint stiffness and reduced range of motion, as mentioned in the complications section. Early, guided mobilization is crucial for rehabilitation.Option B is incorrect:High-dose NSAIDs are used for acute flare management, but their long-term use is often limited by side effects, especially in the elderly with comorbidities like renal impairment. They are not the primary strategy for preventing tophi recurrence.Option D is incorrect:Aggressive passive range of motion exercises immediately post-op can jeopardize wound healing and surgical repairs, especially if tendon or joint capsule repairs were performed. Rehabilitation progresses gradually from protected AROM to PROM.Option E is incorrect:While revision surgery for symptomatic residual tophi may be considered, it is not the primary long-term management strategy for prevention. The goal is to prevent new tophi formation and dissolve existing ones through medical management.

Question 306

Topic: Infection, Pharmacology & VTE
A 62-year-old male presents with acute, severe pain and swelling in his right wrist and multiple MCP joints. He has a history of hyperuricemia but has never been formally diagnosed with gout. His symptoms are accompanied by warmth and erythema. Given the inflammatory nature of his presentation, the orthopedic surgeon considers a differential diagnosis that includes septic arthritis, rheumatoid arthritis, and calcium pyrophosphate deposition disease (CPPD), in addition to gout. An arthrocentesis is performed on the most inflamed MCP joint. The synovial fluid analysis reveals a WBC count of 75,000 cells/mm³ with 92% neutrophils. Gram stain is negative. Which of the following additional findings from the synovial fluid analysis, as shown in the image, would definitively confirm a diagnosis of gout and rule out the other inflammatory conditions?
. A. Presence of positively birefringent, rhomboid-shaped crystals
. B. Identification of negatively birefringent, needle-shaped crystals
. C. Absence of bacteria on culture
. D. Low synovial fluid glucose level
. E. High synovial fluid lactate level

Correct Answer & Explanation

. B. Identification of negatively birefringent, needle-shaped crystals

Explanation

Synovial fluid analysis using polarized light microscopy is the gold standard for definitive diagnosis. Identification of negatively birefringent, needle-shaped MSU crystals definitively confirms gout and differentiates it from septic arthritis, CPPD (which has positively birefringent crystals), and rheumatoid arthritis.

Question 307

Topic: Infection, Pharmacology & VTE

A 24-year-old male presents with a small laceration over the dorsum of the 3rd metacarpophalangeal (MCP) joint sustained during an altercation.

What is the most appropriate initial management and empiric antibiotic of choice?

. Primary closure and oral clindamycin
. Primary closure and oral ciprofloxacin
. Incision, drainage, wound left open, and amoxicillin-clavulanate
. Incision, drainage, delayed primary closure, and cephalexin
. Wound irrigation, primary closure, and IV vancomycin

Correct Answer & Explanation

. Incision, drainage, wound left open, and amoxicillin-clavulanate

Explanation

Human bite wounds ("fight bites") over the MCP joint carry a high risk of deep space infection and septic arthritis. They require formal surgical exploration, irrigation, being left open to heal by secondary intention, and amoxicillin-clavulanate to cover Eikenella corrodens and other oral flora.

Question 308

Topic: Infection, Pharmacology & VTE

A 45-year-old avid aquarist presents with an indolent, slowly enlarging erythematous nodule on his hand. Biopsy reveals noncaseating granulomatous inflammation. Acid-fast bacilli cultures grown at 30 degrees Celsius (86 degrees Fahrenheit) are positive. Which of the following is the most appropriate initial treatment?

. Intravenous Vancomycin and Ceftriaxone
. Oral Amoxicillin-clavulanate
. Oral Clarithromycin and Ethambutol
. Topical Terbinafine
. Emergent surgical amputation of the digit

Correct Answer & Explanation

. Oral Clarithromycin and Ethambutol

Explanation

The clinical scenario is classic for Mycobacterium marinum (fish tank granuloma), which grows optimally at 30 degrees Celsius. Treatment involves prolonged dual antibiotic therapy, typically with clarithromycin and ethambutol, or rifampin.

Question 309

Topic: Infection, Pharmacology & VTE

A 65-year-old man with end-stage renal disease on hemodialysis presents with an acute, excruciatingly painful, red, and swollen right thumb interphalangeal joint. Joint aspiration confirms the presence of negatively birefringent needle-shaped crystals. Given his comorbidities, which of the following is the safest and most appropriate acute pharmacologic management?

. Oral Indomethacin
. Oral Colchicine
. Intra-articular or systemic corticosteroids
. Initiation of oral Allopurinol
. Intravenous Ketorolac

Correct Answer & Explanation

. Intra-articular or systemic corticosteroids

Explanation

In a patient with severe renal impairment, NSAIDs and colchicine are heavily contraindicated due to the risk of toxicity and acute renal failure. Intra-articular or systemic corticosteroids are the safest treatment for an acute gout flare in this setting.

Question 310

Topic: Infection, Pharmacology & VTE

A 55-year-old male with chronic kidney disease stage IV presents with a swollen, erythematous, and exquisitely painful right thumb interphalangeal joint. Aspiration confirms acute gout. Which of the following is the most appropriate initial medical management?

. Oral indomethacin 50 mg TID
. Oral colchicine 1.2 mg followed by 0.6 mg in 1 hour
. Initiation of oral allopurinol 100 mg daily
. Intra-articular injection of a corticosteroid
. Intravenous vancomycin and ceftriaxone

Correct Answer & Explanation

. Intra-articular injection of a corticosteroid

Explanation

In a patient with severe chronic kidney disease, NSAIDs (indomethacin) and colchicine are contraindicated or carry high toxicity risks. An intra-articular corticosteroid injection (or systemic steroids if multiple joints are involved) is the safest and most effective acute treatment.

Question 311

Topic: Infection, Pharmacology & VTE

A 65-year-old male with end-stage renal disease on hemodialysis presents with an acute, severe gout flare in his left wrist. He has a history of severe, recurrent peptic ulcer disease with gastrointestinal bleeding. Which of the following is the most appropriate initial pharmacological treatment?

. Oral indomethacin
. Oral colchicine
. Allopurinol
. Intra-articular corticosteroid injection
. Probenecid

Correct Answer & Explanation

. Intra-articular corticosteroid injection

Explanation

In patients with severe renal impairment (ESRD), systemic colchicine is contraindicated. Nonsteroidal anti-inflammatory drugs (NSAIDs) are also contraindicated given his severe GI bleeding history. An intra-articular corticosteroid injection provides safe, targeted, and rapid relief.

Question 312

Topic: Infection, Pharmacology & VTE

A 40-year-old aquarist presents with a 4-week history of multiple nodular, erythematous lesions ascending in a sporotrichoid pattern along the lymphatic drainage of his right forearm. The lesions began after a minor abrasion sustained while cleaning a fish tank and have been unresponsive to oral cephalexin. Which of the following organisms is the most likely etiology?

. Sporothrix schenckii
. Pasteurella multocida
. Staphylococcus aureus
. Mycobacterium marinum
. Vibrio vulnificus

Correct Answer & Explanation

. Mycobacterium marinum

Explanation

Mycobacterium marinum is an atypical mycobacterium found in fresh and saltwater environments, classically causing 'fish tank granuloma' with lymphatic spread. It is inherently resistant to typical beta-lactam antibiotics and is effectively treated with prolonged courses of clarithromycin, ethambutol, or rifampin.

Question 313

Topic: Infection, Pharmacology & VTE

A 40-year-old patient presents with a lumbrical plus deformity of the ring finger, significantly impacting her ability to perform daily tasks. After a trial of hand therapy, the deformity persists. The surgeon is considering surgical intervention. According to the case, which of the following is an absolute contraindication to surgical intervention for this condition?

. Mild, intermittent pain that is managed with NSAIDs.
. The patient's desire for a non-invasive approach, despite significant functional impairment.
. A dynamic deformity that improves with active-assistive exercises.
. Active infection in the surgical field.
. Unrealistic patient expectations regarding the timeline for recovery.

Correct Answer & Explanation

. Active infection in the surgical field.

Explanation

Correct Answer: DExplanation:The case outlines both indications and contraindications for surgical intervention. Under 'Contraindications for Surgical Intervention', it explicitly states: 'Any active infection in the surgical field is an absolute contraindication to elective hand surgery until adequately treated.'Option A (Mild, intermittent pain): This falls under non-operative management criteria ('Mild to moderate pain managed with NSAIDs, activity modification, splinting') and is not an absolute contraindication.Option B (Patient's desire for non-invasive approach): While patient preference is a factor, it's listed as a reason for non-operative management, not an absolute contraindication. The question asks for anabsolutecontraindication.Option C (Dynamic deformity that improves with active-assistive exercises): This describes a mild deformity that is likely to respond to conservative management and would typically not warrant surgery, but it is not an absolute contraindication if surgery were otherwise indicated.Option E (Unrealistic patient expectations): This is listed as a contraindication, but it is generally considered a relative contraindication that can be addressed through thorough patient education, rather than an absolute one that completely precludes surgery.

Question 314

Topic: Infection, Pharmacology & VTE

A 65-year-old woman presents with a slow-growing mass over the dorsal aspect of the distal interphalangeal (DIP) joint of her index finger. Examination reveals longitudinal grooving of the nail plate. Which underlying joint pathology is most universally associated with this soft tissue lesion?

. Rheumatoid arthritis
. Osteoarthritis
. Gouty arthropathy
. Psoriatic arthritis
. Septic arthritis

Correct Answer & Explanation

. Osteoarthritis

Explanation

Mucous cysts are ganglion cysts that arise from the DIP joint and are nearly universally associated with underlying osteoarthritis of the DIP joint (Heberden's nodes). Nail grooving occurs due to pressure on the germinal matrix.

Question 315

Topic: Infection, Pharmacology & VTE

What is the most common causative bacteria in septic arthritis in children? Review Topic

. Staphylococcus aureus
. Brucella melitensis
. Haemophilus influenzae
. Kingella kingae
. Streptococcus pneumonia

Correct Answer & Explanation

. Staphylococcus aureus

Explanation

The spectrum of causative bacteria and frequency of occurrence of specific pathogens in septic arthritis are similar to those seen in osteomyelitis, with Staphylococcus aureus being the most common. Other common causative organisms include Kingella Kingae, Streptococcus pneumonia, Klebsiella species, Salmonella, Brucella melitensis, and Haemophilus influenzae.

Question 316

Topic: Infection, Pharmacology & VTE

A 30-year-old man has had severe knee pain and swelling for 1 week. He reports he previously had acromioclavicular joint pain that disappeared. He denies any fever. Aspiration of a cloudy fluid from the knee reveals a WBC count of greater than 50,000 with 90% polymorphonucleocytes. While awaiting culture results, what is the most appropriate action?

. Cortisone injection
. Open surgical debridement
. Immediate arthroscopic lavage
. Intravenous vancomycin for presumptive MRSA infection
. Obtain sexual activity history and select appropriate antibiotic

Correct Answer & Explanation

. Obtain sexual activity history and select appropriate antibiotic

Explanation

The patient has polyarticular gonococcal arthritis. Acute septic arthritis in adults can be separated into two major patient groups: young (age 15 to 40 years) healthy, sexually active patients with gonococcal pyogenic arthritis and elderly or immunocompromised patients with nongonococcal septic arthritis. In gonococcal septic arthritis, the infecting organism is Neisseria gonorrhea. It is the most common cause of acute joint infection in persons 15 to 40 years of age in the U.S. The clinical presentation is variable, but typically includes migratory polyarthralgias, fever, rash, urethral or vaginal discharge, and tenosynovitis. A patient with disseminated gonococcal infection may report few genital symptoms. More than 50% of these infections are polyarticular. Because patients with gonococcal septic arthritis are healthy, prompt antibiotic treatment results in a generally good prognosis. MRSA septic arthritis would be associated with fever, more rapid onset of symptoms, and is rarely polyarticular.

Question 317

Topic: Infection, Pharmacology & VTE

03 advancement at age 6 years. What is the most likely diagnosis?

. Osteomyelitis
. Lymphoma
. Eosinophilic granuloma
. Tuberculosis
. Ewing’s sarcomaback answer

Correct Answer & Explanation

. Osteomyelitis

Explanation

Figure 15a shows areas of permeative lucency and sclerosis in the proximal femur as well as evidence of a screw (from the previous trochanteric advancement). Figure 15b shows the CT scan of the femur with possible thickening of the cortex and a moth eaten appearance of the bone. Figure 15c shows the biopsy specimen with mixed inflammatory cells. These are all indicative of osteomyelitis. The first radiographic sign of osteomyelitis tends to be an ill-defined area of lucency, followed by areas of sclerosis and periosteal new bone formation as the bone reacts to the infection. Biopsy specimens should show mixed inflammatory cells.back to this question next question

Question 318

Topic: Infection, Pharmacology & VTE

Six weeks after open reduction internal fixation of a closed tibial pilon fracture, a patient has a draining wound with surrounding erythema and swelling. Radiographs show lucency around screws. What is the most appropriate treatment sequence?

. Start IV antibiotics, obtain wound swab for culture, perform irrigation and debridement and retain hardware
. Start IV antibiotics, obtain deep soft tissue and bone cultures in OR, perform irrigation and debridement and remove hardware
. Obtain wound swab for culture, start IV antibiotics, perform irrigation and debridement and remove hardware
. Obtain deep bone and soft tissue cultures in OR, start IV antibiotics, perform irrigation and debridement and remove hardware

Correct Answer & Explanation

. Obtain deep bone and soft tissue cultures in OR, start IV antibiotics, perform irrigation and debridement and remove hardware

Explanation

Discussion: Management of acutely infected wounds is primarily surgical. Osteomyelitis frequently involves Orthopaedic hardware, which would ideally be removed or replaced given biofilm involvement. Multiple operative cultures of fluid collections, soft tissues and bone should routinely be obtained. Culture yield is highest if cultures are obtained before empiric antibiotic treatment is started. Tissue samples are greatly preferred to swabs, which are notoriously inaccurate.

Question 319

Topic: Infection, Pharmacology & VTE
A 5-year-old boy is seen in the emergency department with a 2-day history of refusing to walk. Examination shows that he has a temperature of 102.2°F (39°C) and limited range of motion of the right hip. The AP pelvic radiograph is normal. The WBC count is normal but the C-reactive protein and erythrocyte sedimentation rate (ESR) are elevated. What is the next step in management?
. IV antibiotics
. Oral antibiotics
. Ibuprofen
. Observation and repeat evaluation in 2 weeks
. Aspiration of the right hip

Correct Answer & Explanation

. Aspiration of the right hip

Explanation

DISCUSSION: The history, physical examination, and laboratory studies suggest a septic hip. Recent studies indicate that a child with elevated ESR, a WBC count of greater than 12,000/mm3, a temperature of greater than 38.5°C, and unwillingness to walk is very likely to have septic arthritis of the hip versus toxic synovitis. The best way to confirm the diagnosis is by hip aspiration. No medications should be started until a diagnosis is made. Toxic synovitis is common, but significantly less likely if three of the above criteria are present. This condition usually responds well to ibuprofen, but requires close observation. Septic hips are considered urgent conditions and therefore a repeat evaluation in 2 weeks is inappropriate. REFERENCES: Herring JA: Tachdjian’s Pediatric Orthopaedics, ed 4. Philadelphia, PA, WB Saunders, 2008, pp 2109-2113. Abel MF (ed): Orthopaedic Knowledge Update: Pediatrics 3. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2006, pp 62-65. Kocher MS, Mandiga R, Murphy JM, et al: A clinical practice guideline for treatment of septic arthritis in children: Efficacy in improving process of care and effect on outcome of septic arthritis of the hip. J Bone Joint Surg Am 2003;85:994-999. Kocher MS, Mandiga R, Zurakowski D, et al: Validation of a clinical prediction rule for the differentiation between septic arthritis and transient synovitis of the hip in children. J Bone Joint Surg Am 2004;86:1629-1635.

Question 320

Topic: Infection, Pharmacology & VTE
Which of the following is considered a specific advantage of using COX-2 inhibitors over COX-1 inhibitors?
. Conversion of arachidonic acid to prostaglandins
. Higher degree of efficacy
. Does not affect platelet function and can be used during the perioperative period
. Can be used in patients with congestive heart failure and renal disease
. High levels of COX-2 (cyclooxygenase) found in normal tissue

Correct Answer & Explanation

. Does not affect platelet function and can be used during the perioperative period

Explanation

DISCUSSION: Inflammation is mediated through two isoforms of cyclooxygenase that convert arachidonic acid to prostaglandins. Selectivity, but not specificity, is one of the unique characteristics of this process that has been able to provide more protection from the effects of gastric mucosal alterations using the COX-2 selective inhibitors. The use of COX-1 selective inhibitors is associated with side effects such as ulcerative conditions and platelet interference, both of which have been difficult to control in the past until the advent of the COX-2 inhibitors. PGE2 inhibition by COX-1 in the intestinal tract can then be bypassed, thereby reducing ulceration complications associated with use of nonsteroidal anti-inflammatory drugs. REFERENCES: Lane JM: Anti-inflammatory medications: Selective COX-2 inhibitors. J Am Acad Orthop Surg 2002;10:75-78. Koval KJ (ed): Orthopaedic Knowledge Update 7. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2002. Pellicci PM, Tria AJ Jr, Garvin KL (eds): Orthopaedic Knowledge Update: Hip and Knee Reconstruction 2. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2000.

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