Pathology Questions for the CST Exam — Practice Free

The primary triggers for Malignant Hyperthermia (MH) are volatile inhalation anesthetics (e.g., Isoflurane, Desflurane, Sevoflurane) and the depolarizing neuromuscular blocking agent Succinylcholine. Pathophysiology: These agents trigger an uncontrolled release of calcium from the sarcoplasmic reticulum in genetically susceptible individuals. Exam Strategy: NBSTSA often asks to identify safe versus unsafe agents. Remember: Nitrous oxide, local anesthetics, and non-depolarizing muscle relaxants (like Vecuronium) are NOT triggers for MH.

Establish a Latex-Safe environment. Patients with spina bifida or multiple childhood surgeries have a significantly higher risk (up to 65%) of developing a latex allergy due to repeated exposure. ST Role: Ensure all catheters, gloves, and drapes are latex-free. NBSTSA Focus: Latex allergy is a Type I hypersensitivity (immediate). Spina bifida is a high-yield red flag patient history.

Class II (Clean-Contaminated). Entry into the urinary tract under controlled conditions without evidence of infection (negative culture) is Class II. Distractor Alert: If the patient had a documented UTI (infected urine) at the time of surgery, the classification would be Class IV.

Waxy Cell Wall (Mycolic Acid). Rationale: Mycobacterium species have a unique cell wall containing high concentrations of mycolic acids (lipids). This waxy layer prevents standard Gram stain dyes from penetrating. Clinical Pearl: These organisms require an Acid-Fast Stain (such as Ziehl-Neelsen or Kinyoun). On the exam, if you see Acid-Fast Bacillus (AFB), immediately think Tuberculosis.

It is highly resilient in moist environments and can survive in minimal nutrient conditions, even forming biofilms on stainless steel and within water lines. CST Exam Strategy: This pathogen is often linked to water-borne transmission in the hospital. NBSTSA may ask about it in the context of hydrotherapy tanks (for burns) or improperly dried endoscopes. Remember: *Pseudomonas* is a Gram-negative, non-spore-forming rod, but its ability to survive in wet areas makes it a unique environmental threat in the OR.