I now have all the information needed. Here are the detailed answers to all three questions:
Question 1: Monoclonal Antibody Against Glycoprotein IIb/IIIa?
Answer: Abciximab (ReoPro)
Explanation:
GP IIb/IIIa is the final common receptor for platelet aggregation - fibrinogen cross-links adjacent platelets by binding to this receptor. Three GP IIb/IIIa inhibitors exist, but only one is a true monoclonal antibody:
| Drug | Type | Binding |
|---|
| Abciximab | Chimeric monoclonal antibody (Fab fragment) | Irreversible |
| Eptifibatide | Synthetic heptapeptide | Reversible |
| Tirofiban | Synthetic small molecule | Reversible |
Abciximab's irreversible binding means its effects last 24-48 hours even after stopping the infusion (platelet function only returns as new platelets are produced). The question specifically asks for a monoclonal antibody - only abciximab qualifies.
- Tintinalli's Emergency Medicine, Glycoprotein IIb/IIIa Inhibitors
Question 2: Child Elbow X-ray - Classification and Grade?
Answer: B - Gartland's classification, Type III
Explanation:
The X-ray shows a supracondylar humeral fracture in a child, which is the most common elbow fracture in the pediatric age group. The standard classification used is the Gartland classification (not Salter-Harris, which applies to physeal/growth plate injuries):
| Gartland Type | Description | Treatment |
|---|
| Type I | Nondisplaced | Cast/splint |
| Type IIA | Displaced, posterior cortex intact, no rotation | Closed reduction |
| Type IIB | Displaced, posterior cortex intact, with rotation | Often pinning |
| Type III | Completely displaced, no cortical contact | Surgical - CRPP |
| Type IV | Complete periosteal disruption, multidirectionally unstable | Surgical |
The X-ray shows complete displacement with loss of cortical contact at the distal humerus, consistent with Type III. The arrow points to the fracture line with obvious displacement. This requires closed reduction and percutaneous pinning (CRPP).
- Rosen's Emergency Medicine, Supracondylar Fractures of the Humerus
- Campbell's Operative Orthopaedics 15th Ed
Note: Salter-Harris classification is used for physeal (growth plate) injuries (Types I-V based on Salter-Harris criteria). Supracondylar fractures are metaphyseal fractures - Gartland's is the correct system.
Question 3: Organism Unlikely in CF Sputum?
Answer: B - Acinetobacter baumannii
Explanation:
Cystic fibrosis patients have a well-established pattern of respiratory infections that evolves with age:
Organisms commonly found in CF sputum:
- Haemophilus influenzae - early childhood colonizer (option a - FOUND)
- Staphylococcus aureus (including MRSA) - common at all ages
- Pseudomonas aeruginosa - the classic CF pathogen, dominant in adults
- Burkholderia cepacia (now B. cenocepacia) - serious late-stage CF pathogen; notorious for causing "cepacia syndrome" (option c - FOUND)
- Aspergillus fumigatus - causes ABPA (allergic bronchopulmonary aspergillosis) in CF (option d - FOUND)
Acinetobacter baumannii is classically associated with:
- Hospital-acquired/ventilator-associated pneumonia in ICU patients
- Immunocompromised/critically ill patients
- Burn wound infections
It is not a recognized pathogen in the CF lung microbiome. While rare co-infections can occur, it is the least likely among the options listed.
- Morgan and Mikhail's Clinical Anesthesiology: "Cystic fibrosis → H. influenzae (early), P. aeruginosa, Burkholderia cepacia"
Summary of answers:
- Abciximab (chimeric monoclonal antibody, irreversible GP IIb/IIIa inhibitor)
- B - Gartland's classification, Type III (completely displaced supracondylar fracture)
- B - Acinetobacter baumannii (not a classic CF pathogen)