Medications on the Sterile Field
The scrub person is responsible for identifying, labeling, and managing all medications and solutions on the sterile field, and for verbally confirming each with the circulator before use. This section is a fast-recall summary of the drug classes most tested on the CST exam.
Local Anesthetics
| Drug | Onset/Duration | Note |
|---|
| Lidocaine | Fast onset, short-intermediate duration | Common for local infiltration and nerve blocks; also available with epinephrine |
| Bupivacaine (Marcaine) | Slower onset, long duration | Used for prolonged postoperative pain control |
| Ropivacaine | Intermediate onset, long duration | Similar to bupivacaine with a reduced cardiotoxicity profile |
Hemostatic and Vasoconstrictive Agents
| Drug | Purpose |
|---|
| Epinephrine | Vasoconstriction to reduce bleeding and prolong local anesthetic effect; avoided in end-arterial tissue |
| Topical thrombin | Converts fibrinogen to fibrin at the bleeding site |
| Tranexamic acid (TXA) | Antifibrinolytic used to reduce blood loss in select procedures |
Irrigation Solutions
| Solution | Use |
|---|
| Normal saline (0.9% NaCl) | General wound and cavity irrigation |
| Sterile water | Used in some oncologic cases for its cytolytic effect on residual tumor cells |
| Antibiotic irrigation | Diluted antibiotic solution used per surgeon order to reduce bacterial load |
| Glycine or sorbitol solution | Non-electrolyte irrigant for monopolar resectoscope procedures (e.g., TURP) to avoid electrical conduction |
Contrast and Diagnostic Agents
| Agent | Use |
|---|
| Iodinated contrast media | Intraoperative cholangiography, angiography; screen for iodine/shellfish allergy history |
| Methylene blue / indigo carmine | Identifying ureters, fistula tracts, or confirming anastomotic integrity |
Antibiotics
Prophylactic IV antibiotics are typically administered by anesthesia within 60 minutes before incision (per Surgical Care Improvement Project/SSI prevention guidelines) to achieve adequate tissue levels at the time of incision. Antibiotic irrigation may also be used directly in the wound per surgeon preference.
Medication Safety on the Field
- All medications and solutions are labeled immediately upon receipt onto the sterile field, including name, strength/concentration, and time if applicable.
- Verbal confirmation ("read-back") between scrub and circulator is completed for every medication passed to the field.
- Look-alike containers (saline vs. local anesthetic vs. contrast) are a leading cause of OR medication errors - always verify visually and verbally.
- Unlabeled medications/solutions on the sterile field must be discarded - never assumed or guessed.
Key Exam Points
- Know which agents are avoided in end-arterial anatomy (epinephrine) and why.
- Understand why nonconductive irrigants (glycine, sorbitol) are required for monopolar resectoscope procedures.
- Recognize signs of local anesthetic systemic toxicity (LAST) as a rare but serious complication and the surgical tech's role in staying alert to changes reported by anesthesia.