13.2 Intraoperative Standards, Surgical Time-Out & Anesthesia Monitoring

13.2 Intraoperative Standards, Surgical Time-Out & Anesthesia Monitoring

The intraoperative environment demands precise execution of safety protocols, strict infection control, seamless transdisciplinary communication, and vigilant physiological monitoring. In Singapore operating theatres, intraoperative practices are structured around guidelines from the Ministry of Health (MOH), the Singapore Nursing Board (SNB), and international perioperative standards adapted for local acute healthcare clusters.

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Mandatory Intraoperative Safety Frameworks: The MOH Surgical Safety Checklist

To eliminate wrong-site, wrong-procedure, and wrong-patient surgical events, MOH mandates the application of the adapted WHO Surgical Safety Checklist across all public and private hospital operating suites in Singapore. The checklist is divided into three distinct chronological phases, each requiring active verbal verification.

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Roles of Scrub and Circulating Nurses & Count Verification Standards

Perioperative nursing excellence relies on the distinct, complementary roles of the Scrub Nurse and the Circulating Nurse. Both roles require rigorous adherence to aseptic technique, environmental control, and patient advocacy under the SNB Standards for Nursing Practice.

Core Intraoperative Nursing Roles

• Scrub Nurse (Sterile Role): Performs surgical hand scrub, dons sterile gown and gloves, sets up sterile tables, maintains sterile field integrity, hands instruments and supplies to the surgeon, monitors sterile technique of the surgical team, and performs audible item counts.
• Circulating Nurse (Non-Sterile Role): Manages overall operating room environment, prepares non-sterile equipment, positions the patient safely, leads the Surgical Time-Out, opens sterile supplies for the scrub nurse, monitors patient physiological parameters, maintains real-time perioperative documentation, and conducts audible item counts.

Four-Stage Surgical Count Protocol

Surgical counts of sponges (gauze, laparotomy sponges, peanuts), sharps (needles, blades), and surgical instruments are mandatory to prevent Retained Surgical Items (RSIs). Counts must be performed independently, visually, and audibly by both the scrub and circulating nurses concurrently at four mandatory intervals:

1. Initial Count: Prior to the start of the surgical procedure (during room setup).
2. Cavity Count: Before closing any deep body cavity or organ space (e.g., peritoneum, pleura, joint capsule).
3. Closure Count: During closure of subcutaneous layers / fascia.
4. Final Count: At skin closure or completion of procedure.

Discrepancy Protocol for Incorrect Counts

If a count discrepancy occurs at any stage, the scrub and circulating nurses must execute the following immediate steps:

1. Notify the Operating Surgeon Immediately: Inform the surgeon that the count is incorrect; the surgeon must pause wound closure if safe to do so.
2. Perform Search: Re-count the specific item group audibly. Check the sterile field, instrument tables, floor, kick-buckets, trash containers, and linen bags.
3. Perform Anatomical Exploration: The surgeon manually inspects and searches the surgical cavity and wound site.
4. Order Intraoperative Radiography: If the missing item is not accounted for, an intraoperative X-ray (mobile C-arm or plain radiography) must be ordered and reviewed by the surgeon/radiologist before the patient leaves the OT suite.
5. Incident Reporting: Log an official clinical incident report via the institution's electronic incident reporting system (e.g., Riskman) as per MOH patient safety governance standards.

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Anesthesia Monitoring & Emergency Crisis Management: Malignant Hyperthermia

Intraoperative anesthesia care involves continuous monitoring of physiological homeostasis and immediate intervention during life-threatening crises.

Anesthesia Phases and Physiological Targets

• Induction & Airway Management: Monitoring for laryngospasm, bronchospasm, hypotension, or difficult airway. End-tidal CO2 (EtCO2) capnography is mandatory to confirm endotracheal tube placement.
• Maintenance Phase: Continuous monitoring of ECG, non-invasive or invasive arterial blood pressure, core body temperature, SpO2, neuromuscular blockade, and depth of anesthesia (e.g., Bispectral Index [BIS] target 40-60).
• Malignant Hyperthermia (MH) Crisis Protocol: MH is a rare, life-threatening pharmacogenetic autosomal dominant disorder of skeletal muscle triggered by volatile inhalational anesthetics (e.g., sevoflurane, desflurane, isoflurane) or depolarizing muscle relaxants (succinylcholine), causing uncontrolled intracellular calcium release.

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Patient Positioning, Ergonomics & Intraoperative Injury Prevention

Proper intraoperative positioning ensures optimal surgical access while preventing peripheral nerve damage, joint strain, and skin breakdown.

• Supine Position: Ensure head alignment, cushion pressure points (occiput, sacrum, heels), and keep arms abducted < 90° to prevent brachial plexus nerve injury.
• Lithotomy Position: Ensure simultaneous lifting and lowering of legs into stirrups to prevent hip dislocation or lumbar strain. Pad the peroneal nerve area over the lateral fibular head to prevent common peroneal nerve palsy (foot drop).
• Prone Position: Support chest and pelvis to allow unhindered diaphragm excursion; protect eyes and nose from direct pressure to prevent blindness (central retinal artery occlusion) and facial pressure injuries.
• Electrosurgical Safety (Diathermy): The circulating nurse must position the neutral return electrode (dispersive ground pad) over a clean, well-vascularized, large muscle mass (e.g., thigh or upper arm) close to the surgical site. Avoid bony prominences, scar tissue, metal implants, or hairy surfaces to prevent severe thermal electrical burns.