9.2 Intraoperative Care, Surgical Asepsis & WHO Surgical Safety Checklist
Key Takeaways
- Operating theater suites are engineered into three progressive environmental zones—unrestricted, semi-restricted, and restricted—maintained under positive pressure ventilation with 15–20 air changes per hour to prevent airborne microbial contamination.
- The core doctrine of surgical asepsis dictates that sterile surfaces only contact sterile items, sterile fields exist strictly above table and waist level, gown backs and a 1-inch (2.5 cm) drape perimeter are unsterile, and any moisture causes strike-through contamination.
- The surgical team divides into sterile personnel (Scrub Nurse, Surgeons) who manage the operative field and instrumentation, and unsterile personnel (Circulating Nurse, Anesthetist) who manage patient positioning, safety, documentation, and surgical counts.
- Surgical counts of sponges, needles, blades, and instruments must be performed aloud by both scrub and circulating nurses at three mandatory milestones: baseline before incision, immediately before cavity closure, and during skin closure.
- The WHO Surgical Safety Checklist enforces systematic team verification across three critical junctures: Sign In (before induction), Time Out (before incision, verifying antibiotic administration within 60 minutes), and Sign Out (before leaving theater).
9.2 Intraoperative Care, Surgical Asepsis & WHO Surgical Safety Checklist
Quick Answer: The intraoperative phase begins when the patient is transferred onto the operating table and concludes upon admission into the PACU. Safe intraoperative care relies on strict adherence to surgical asepsis (sterile-to-sterile contact, maintaining sterile boundaries above waist level, and preventing moisture strike-through), clear delineation between the sterile Scrub Nurse and unsterile Circulating Nurse, systematic surgical counts at three distinct milestones, execution of the three-phase WHO Surgical Safety Checklist (Sign In, Time Out, Sign Out), and meticulous patient positioning to prevent peripheral neuropraxia and electrosurgical burns.
Operating Theater Architecture & Environmental Zoning
Operating theater design minimizes microbial contamination by segregating personnel traffic, air movement, and sterile supplies into three progressive zones.
+---------------------------------------------------------------------------------------------------+
| OPERATING THEATER ENVIRONMENTAL ZONING |
+-----------------------------------+-----------------------------------+---------------------------+
| 1. UNRESTRICTED ZONE | 2. SEMI-RESTRICTED ZONE | 3. RESTRICTED ZONE |
+-----------------------------------+-----------------------------------+---------------------------+
| • Street clothes permitted | • Scrub attire (shirt & pants) | • Scrub attire & cap |
| • Outer reception & holding bay | • Surgical hair cap covering hair | • Full surgical face mask |
| • Staff locker rooms & offices | • Dedicated theater footwear | • Protective eyewear |
| • Transfer bays & corridors | • Clean hallways & scrub sinks | • Operating room suites |
| • Family waiting areas | • Storage bays for clean sterile | • Sterile supply cores |
| | packs and processing | • Scrub procedure suites |
+-----------------------------------+-----------------------------------+---------------------------+
Theater Engineering & Environmental Parameters
- Positive Pressure Ventilation: Operating rooms are maintained under positive air pressure relative to surrounding semi-restricted corridors. When theater doors open, air flows outward into the corridor, preventing airborne micro-organisms and dust from entering the sterile surgical field.
- Air Exchange Rates: Theater ventilation systems must deliver a minimum of 15 to 20 total air changes per hour, with at least 3 to 4 changes utilizing fresh outdoor air, filtered through High-Efficiency Particulate Air (HEPA) filters that remove particles down to 0.3 microns.
- Temperature and Humidity: Room temperature is strictly regulated between 20°C and 24°C (68°F–75°F). This suppresses microbial growth and keeps the scrubbed team comfortable while preventing intraoperative patient hypothermia. Relative humidity is maintained between 20% and 60%; humidity <20% increases static electrical discharge (fire hazard), while >60% promotes bacterial proliferation and condensation on sterile packaging.
Principles and Practice of Surgical Asepsis
Surgical asepsis (sterile technique) aims to prevent surgical site contamination by rendering all instruments, drapes, and surfaces entirely free of all microorganisms, including bacterial spores.
+---------------------------------------------------------------------------------------------------+
| THE GOLDEN RULES OF SURGICAL ASEPSIS |
+---------------------------------------------------------------------------------------------------+
| 1. Sterile-to-Sterile Only: Only sterile items may contact sterile fields; any contact with |
| an unsterile item immediately contaminates the entire field. |
| 2. Sterile Anatomical Boundaries: Gowns are sterile ONLY on the front from chest to level of |
| sterile field; sleeves sterile from 2 inches above elbow to cuff. |
| 3. Unsterile Gown Zones: The back of the surgical gown, neckline, shoulders, underarms, and |
| cuffs (once hands pass through) are considered UNSTERILE. |
| 4. Table Surface Sterility: Surgical drapes are sterile ONLY on the flat horizontal tabletop; |
| any drape portion hanging over the table edge is UNSTERILE. |
| 5. Perimeter Boundary Margin: The outermost 1-inch (2.5 cm) margin of an unwrapped sterile drape|
| or package is considered UNSTERILE. |
| 6. Strike-Through Prevention: Moisture penetrating a sterile barrier wicks pathogens via |
| capillary action; any wet sterile package is CONTAMINATED. |
| 7. Spatial Vigilance: Sterile personnel must face the sterile field at all times; |
| unsterile personnel maintain at least 12 inches (30 cm) distance. |
+---------------------------------------------------------------------------------------------------+
- Strike-Through Contamination: When sterile drapes or wrappers become wet from irrigation fluids, blood, or saline, liquids permeate the porous fibers via capillary action, pulling microorganisms from underlying unsterile surfaces into the sterile field. Wet drapes must be replaced or covered with an impervious sterile barrier drape immediately.
- Movement Within Theater: Scrubbed personnel must pass each other either back-to-back or face-to-face, maintaining sterile contact. Unsterile personnel must never reach across a sterile trolley or field when opening packages or pouring liquids; liquids are poured from a height of 15 to 20 cm into the basin at the edge of the trolley.
Surgical Team Roles: Scrub Nurse vs. Circulating Nurse
Intraoperative nursing relies on two primary nursing roles functioning in synchronized coordination.
| Clinical Dimension | Scrub Nurse (Sterile Role) | Circulating Nurse (Non-Sterile Role) |
|---|---|---|
| Surgical Attire | Sterile surgical gown, sterile gloves, surgical cap, mask, eye protection. | Clean scrub suit, surgical cap, mask, eye protection, theater shoes; no gown or sterile gloves. |
| Sterility Status | Completely scrubbed and maintains strict surgical sterility. | Non-sterile; remains outside the sterile perimeter but inside the theater. |
| Core Functions | Performs surgical hand scrub; gowns and gloves self and surgeons; drapes the patient; arranges instruments and sterile supplies on Mayo stand and trolleys. | Manages theater logistics; receives and identifies patient; verifies consent and site; assists anesthetist; manages positioning; applies skin prep; connects suction and electrosurgical lines. |
| Instrument Handling | Previews surgical steps; passes instruments, sponges, and sutures to the surgeon with speed and safety; keeps sharps isolated. | Opens sterile packages onto the sterile field using aseptic non-touch technique; dispenses sterile fluids; handles non-sterile supplies. |
| Accountability & Counts | Conducts sponge, needle, blade, and instrument counts jointly with the circulating nurse; keeps all items organized on the sterile field. | Conducts counts jointly with the scrub nurse; records counts immediately on the theater whiteboard/register; reports count status to surgeon. |
| Specimen Handling | Receives tissue specimens from surgeon; places them in sterile container or basin on field; passes them off to circulating nurse. | Receives specimen from scrub nurse; places into appropriate fixative (e.g., 10% formalin); verifies labeling with patient details and source. |
| Advocacy & Safety | Protects the sterile field from contamination; alerts team instantly if a breach occurs. | Acts as the patient's primary advocate; monitors environmental parameters, theater traffic, asepsis breaches, and patient skin integrity. |
Surgical Counts Protocol & Discrepancy Management
Retained Surgical Items (RSIs)—such as sponges, needles, and instruments left inside a patient's body cavity—represent catastrophic, preventable medical errors resulting in sepsis, bowel perforation, re-operation, and death.
The Three Mandatory Count Milestones
- Baseline Initial Count: Performed before the surgical skin incision is made. Establishes the baseline inventory for every single item on the field.
- Cavity Closure Count: Performed immediately before the surgeon begins closing any deep anatomical cavity or hollow organ (e.g., peritoneum, pleura, pericardium, uterus, joint capsule).
- Final Skin Closure Count: Performed during the closure of subcutaneous tissue and skin margins.
Note: An additional count must be executed whenever there is a relief or permanent handover of either the scrub nurse or circulating nurse during the procedure.
Execution of the Count
- Counts must be performed audibly and visually by the scrub nurse and circulating nurse simultaneously.
- Gauzes and sponges must be unfolded, separated, and counted individually (never counted as a bundled pack).
- Sponges used in theater must contain radiopaque markers (e.g., Ray-Tec sponges, laparotomy pads) visible on X-ray.
Discrepancy Management Protocol (Incorrect Count)
If an item count does not balance at any milestone, the team must execute the following protocol:
+---------------------------------------------------------------------------------------------------+
| INCORRECT COUNT DISCREPANCY PROTOCOL |
+---------------------------------------------------------------------------------------------------+
| 1. NOTIFY SURGEON: Inform operating surgeon immediately; surgeon must PAUSE wound |
| closure; DO NOT close the cavity or skin. |
| 2. SYSTEMATIC SEARCH: Scrub nurse searches sterile field, Mayo stand, and drapes; |
| Circulating nurse searches floor, kick buckets, linen, and trash. |
| 3. FORMAL RECOUNT: Conduct a complete, audible recount of all items in that category. |
| 4. WOUND EXPLORATION: If still missing, surgeon performs manual wound exploration. |
| 5. RADIOGRAPHIC SCREENING: If unresolved, obtain immediate intraoperative portable X-ray |
| to visualize radiopaque marker BEFORE the patient leaves theater. |
| 6. DOCUMENTATION: Document exact findings, X-ray results, and file an institutional |
| incident / adverse event variance report. |
+---------------------------------------------------------------------------------------------------+
The WHO Surgical Safety Checklist
The World Health Organization (WHO) Surgical Safety Checklist is a proven, evidence-based tool that significantly reduces surgical morbidity and mortality by enforcing structured interprofessional communication across three critical procedural junctures.
+---------------------------------------------------------------------------------------------------+
| WHO SURGICAL SAFETY CHECKLIST PHASES |
+-----------------------------------+-----------------------------------+---------------------------+
| 1. SIGN IN | 2. TIME OUT | 3. SIGN OUT |
| (Before Induction of Anesthesia) | (Before Surgical Skin Incision) | (Before Leaving Theater) |
+-----------------------------------+-----------------------------------+---------------------------+
| • Patient confirms identity, site,| • ENTIRE team pauses together | • Nurse verbally confirms:|
| procedure, and written consent | • All members introduce themselves| - Name of recorded |
| • Surgical site marked by surgeon | by name and clinical role | procedure performed |
| • Pulse oximeter attached & active| • Verbally confirm: patient name, | - Sponge, needle, and |
| • Known allergy history reviewed | exact procedure, & site/side | instrument count ok |
| • Difficult airway & aspiration | • Anticipated critical events: | - Correct labeling of |
| risk evaluated; equipment ready | - Surgeon: blood loss & duration| pathology specimens |
| • Risk of blood loss >500 mL | - Anesthetist: patient concerns | - Equipment issues noted|
| (>7 mL/kg in children) assessed;| - Nursing: sterility & kit check| • Key postoperative PACU |
| IV access and blood confirmed | • Antibiotic prophylaxis given | recovery concerns |
| | within 60 min before incision | reviewed by team |
| | • Essential imaging displayed | |
+-----------------------------------+-----------------------------------+---------------------------+
[!IMPORTANT] Exam Alert: Antibiotic Prophylaxis Timing during Time Out Licensure examinations frequently test the exact timing of surgical antimicrobial prophylaxis. Under the WHO Checklist (Time Out phase) and CDC guidelines, intravenous prophylactic antibiotics (e.g., cefazolin) must be completely infused within 60 minutes prior to the surgical skin incision (or within 120 minutes for vancomycin or fluoroquinolones) to ensure peak tissue drug concentrations when the incision is made.
Intraoperative Patient Positioning & Neuromuscular Safety
Proper surgical positioning provides optimal anatomical exposure for the surgical team while maintaining respiratory excursion, cardiovascular stability, and protecting peripheral nerves and skin from ischemic injury.
| Surgical Position | Common Surgical Indications | Vulnerable Nerves & Tissues | Nursing Prevention Measures |
|---|---|---|---|
| Supine (Dorsal Recumbent) | Abdominal, open heart, vascular, orthopedic, and ENT surgery | Brachial Plexus; pressure necrosis over occiput, scapulae, sacrum, and calcaneus (heels). | Keep arm abduction on armboards strictly <90 degrees to prevent brachial plexus stretch injury; place silicone pads under heels and sacrum; ensure palms are supinated. |
| Lithotomy | Vaginal hysterectomy, cystoscopy, transurethral resections, and perineal/colorectal surgery | Common Peroneal (Fibular) Nerve; Saphenous Nerve; lumbosacral strain. | Raise and lower both legs simultaneously to prevent pelvic torsion and hypotension; pad stirrup metal supports to prevent compression of common peroneal nerve against fibular head (prevents foot drop); pad medial knee against saphenous nerve compression. |
| Prone | Spinal fusion, laminectomy, pilonidal sinus excision, posterior fossa craniotomy | Eyes (ischemic optic neuropathy); brachial plexus; breasts; male genitalia. | Position head on foam cradle with eye cutouts (avoid direct ocular globe compression); place bilateral chest rolls from clavicle to iliac crest to allow diaphragmatic descent; ensure male penis and scrotum hang free without compression. |
| Trendelenburg (Head-Down Tilt) | Lower abdominal, gynecological, and pelvic surgeries (retracts bowel cephalad) | Increased intracranial pressure (ICP); increased intraocular pressure (IOP); reduced lung compliance. | Use padded shoulder braces cautiously to avoid brachial plexus compression; avoid prolonged steep tilt; monitor for facial edema and respiratory restriction upon leveling. |
| Reverse Trendelenburg (Head-Up Tilt) | Gallbladder (laparoscopic cholecystectomy), stomach, head and neck surgery | Peripheral venous pooling in lower extremities; deep vein thrombosis (DVT); sliding downward. | Fasten a padded footboard perpendicular to the table to prevent sliding; apply graduated compression stockings or intermittent pneumatic compression (IPC) sleeves. |
| Lateral Decubitus | Thoracotomy, pulmonary lobectomy, nephrectomy, total hip arthroplasty | Brachial plexus (dependent arm); common peroneal nerve (dependent leg); ear; trochanter. | Place an axillary roll beneath the dependent chest (just below the axillary apex) to protect axillary neurovascular bundle; place a pillow between flexed legs; support dependent ear. |
[!CAUTION] Clinical Pearl: The Mechanism of Foot Drop in Lithotomy Compression of the common peroneal nerve at the lateral neck of the fibula against the hard metal rod of a lithotomy stirrup is the most frequent positioning-related peripheral nerve injury in surgical nursing. It manifests as post-anesthesia weakness in foot dorsiflexion (foot drop) and paresthesias over the dorsal foot. Meticulous padding of lateral knee stirrups is mandatory.
Electrosurgical Safety & Grounding Principles
Electrosurgical Units (ESUs / diathermy) utilize high-frequency electrical currents to cut tissue and coagulate bleeding vessels.
- Monopolar Electrosurgery: Current flows from the electrosurgical generator, through the active handpiece electrode (pencil) into the target tissue, travels through the patient's body, and exits via a dispersive electrode (grounding plate / neutral pad) back to the generator.
- Grounding Plate Application Rules:
- Apply over a clean, dry, intact, and well-vascularized large muscle mass (such as the anterolateral thigh, calf, or buttock).
- Avoid Bony Prominences: Never place over the iliac crest, sacrum, tibia, or scapula (poor contact surface creates high electrical resistance, concentrating heat and causing severe full-thickness burns).
- Avoid Metal Implants: Never place over or adjacent to orthopedic joint prostheses or internal fixation plates (metal conducts current, producing thermal necrosis of surrounding bone and tissue).
- Avoid Scar Tissue and Hairy Skin: Clip excessive hair and avoid scar tissue to ensure 100% surface contact.
- Ensure skin prep solutions (especially alcohol-based) are completely dry before draping to prevent surgical fires ignited by electrosurgical sparks.
During an open abdominal laparotomy, the circulating nurse and scrub nurse perform the surgical sponge count immediately prior to closure of the peritoneum. The circulating nurse announces that one laparotomy sponge is missing from the baseline count. What is the immediate priority action of the surgical nursing team?
In accordance with the World Health Organization (WHO) Surgical Safety Checklist, during which operational phase must the surgical team verbally confirm that prophylactic antibiotics have been administered within 60 minutes prior to surgical incision?
A female client undergoes a 3-hour vaginal hysterectomy in the lithotomy position. Postoperatively, the nurse notes that the client cannot dorsiflex her right foot and drags her toes when attempting to walk (foot drop). Which nerve was most likely injured due to improper padding against the lithotomy stirrup?