5.2 Scene Safety, Primary Survey & Triage

5.2 Scene Safety, Primary Survey & Triage

Core Principle: In maritime emergencies, the initial responder's primary duty is to preserve life without expanding the disaster. Rushing into an unassessed compartment, touching an energized casualty, or failing to identify catastrophic hemorrhage converts the rescuer into a secondary casualty, crippling the vessel's emergency response.

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1. Shipboard Scene Safety & Rescuer Protection

Maritime environments present dynamic, high-consequence hazards rarely encountered in shoreside first aid. Ships are floating industrial complexes characterized by confined compartments, high-voltage electrical distribution, complex piping systems, pressurized steam, combustible fuels, and heavy rolling machinery subject to vessel motion in seaways.

                    SHIPBOARD HAZARD ASSESSMENT MATRIX

  ATMOSPHERIC HAZARDS        ELECTRICAL & MECHANICAL       DYNAMIC VESSEL MOTIONS
  • Toxic gases (H₂S, CO)    • High voltage (440V / 6.6kV) • Vessel rolling & pitching
  • Oxygen deficiency (<19.5%) • Unguarded winches & shafts • Shifting unlashed cargo
  • Flammable hydrocarbon gas • Pressurized steam lines     • Open bilge wells & hatches

The Cardinal Rule: Never Become a Secondary Casualty

Every maritime accident investigation confirms that untrained or impulsive entry into hazardous areas is a leading cause of multi-casualty shipboard fatalities. Over 50% of enclosed space fatalities at sea are would-be rescuers who entered without breathing apparatus or atmospheric testing.

Mandatory Rescuer Personal Protective Equipment (PPE)

Before making physical contact with any casualty or entering an incident zone, the first responder must don appropriate PPE:

• Nitrile / Latex Medical Gloves: Primary barrier against bloodborne pathogens (HIV, Hepatitis B and C) and hazardous chemical contaminants.
• Eye Protection / Safety Goggles: Shielding against arterial blood spurts, bodily fluid splashes, and airborne particulate.
• Surgical / N95 Face Mask: Protection against respiratory droplets, airborne contaminants, and aerosolized fluids during airway maneuvers.
• Hard Hat & Steel-Toe Safety Boots: Mandatory baseline shipboard PPE to protect against swinging crane loads, rolling deck cargo, and overhead obstructions.
• Self-Contained Breathing Apparatus (SCBA) & Atmospheric Gas Detector: Required prior to entering any compartment where toxic gases (e.g., hydrogen sulfide, carbon monoxide, hydrocarbon vapors) or oxygen deficiency (<19.5% O₂) are possible.

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2. The Primary Assessment Algorithm: DR CABC / DRSABCD

The primary survey is a rapid, systematic 60-to-90-second evaluation designed to identify and immediately treat life-threatening conditions in order of physiological lethality.

                     PRIMARY SURVEY SYSTEMATIC FLOW

     [D] DANGER        ──► Verify scene safety; don PPE; check for shipboard hazards
          │
     [R] RESPONSE      ──► Assess level of consciousness using AVPU scale
          │
     [C] CATASTROPHIC  ──► Immediately arrest massive arterial spurting hemorrhage
         HEMORRHAGE
          │
     [A] AIRWAY        ──► Open & clear airway (Head-Tilt Chin-Lift vs Jaw-Thrust)
          │
     [B] BREATHING     ──► Look, listen, feel for 10 seconds; check for normal breaths
          │
     [C] CIRCULATION   ──► Assess carotid pulse, skin color, temperature, cap refill
          │
     [D] DISABILITY /  ──► Rapid neurological check (GCS/Pupils) & AED attachment
         DEFIBRILLATION

Detailed Step-by-Step Breakdown

Exam Watchout: Modern emergency trauma doctrine prioritizes Catastrophic Hemorrhage ("C") before Airway ("A"). A casualty with a severed femoral or brachial artery can exsanguinate completely in 60 to 120 seconds. If massive spurting bleeding is identified, it must be occluded instantly with a tourniquet or direct pressure before positioning the airway.

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3. Assessing Level of Consciousness: The AVPU Scale

The AVPU scale is the international standard for rapid, repeatable assessment of a casualty's neurological status and central nervous system depression.

                          THE AVPU CONSCIOUSNESS SPECTRUM

    [A] ALERT          ──► Awake, responsive, oriented to person, place, and time
    [V] VOICE          ──► Opens eyes, groans, or moves only when loudly addressed
    [P] PAIN           ──► Responds only to painful stimulus (trapezius pinch / nail bed)
    [U] UNRESPONSIVE   ──► Zero motor, verbal, or ocular response to any stimulus

Clinical Application of AVPU

• A — Alert: The mariner is spontaneously conscious, eyes open, tracking movement, and capable of answering simple orientation questions ("What is your name? What ship is this? What day is it?").
• V — Voice (Verbal): The mariner appears asleep or lethargic but responds when spoken to loudly or when given a direct verbal command ("Open your eyes!"). Responses may be confused, slurred, or limited to groaning.
• P — Pain (Painful): The casualty does not respond to verbal shouting but exhibits purposeful or non-purposeful motor movement (withdrawing, grimacing, posturing) to a localized painful stimulus.
  • Approved Painful Stimuli: Firm trapezius muscle pinch or fingernail bed pressure with a pen.
  • Avoid: Vigorous sternal rubs (which cause soft tissue bruising and can destabilize thoracic fractures) or pinching sensitive nipple/orbital tissue.
• U — Unresponsive: The casualty shows complete absence of eye opening, verbalization, or motor response to both verbal and painful stimuli. An unresponsive state indicates a critical life threat requiring immediate airway protection and medical escalation.

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4. Airway Management & Foreign Body Obstruction (FBAO)

In an unconscious supine casualty, loss of muscle tone causes the base of the tongue and the epiglottis to relax posteriorly against the posterior pharyngeal wall, creating complete anatomical airway occlusion.

                           AIRWAY OPENING TECHNIQUES

        HEAD-TILT CHIN-LIFT                        JAW-THRUST MANEUVER
    [Medical / Non-Trauma Patient]              [Suspected Cervical Spine Trauma]
                 ▲                                             ▲
                 │                                             │
   • Place hand on forehead; tilt back           • Position at patient's head
   • Place fingertips under bony chin            • Place fingers behind angle of mandible
   • Lift chin anteriorly to stretch neck        • Thrust mandible upward without neck tilt

Airway Technique Selection Matrix

Foreign Body Airway Obstruction (FBAO) Management

Shipboard choking emergencies frequently occur in galleys and mess decks. Responders must immediately distinguish between mild (partial) and severe (complete) airway obstruction.

                   ADULT CONSCIOUS CHOKING ESCALATION LADDER

    [MILD OBSTRUCTION]   ──► Coughing forcefully, speaking ──► Encourage coughing; monitor
                                                                      │
                                                     Obstruction becomes severe
                                                                      │
                                                                      ▼
    [SEVERE OBSTRUCTION] ──► Silent, cannot speak/cough,  ──► Deliver 5 BACK BLOWS
                             universal choking sign                   │
                                                              Followed by
                                                                      │
                                                                      ▼
                                                             Deliver 5 ABDOMINAL
                                                                   THRUSTS
                                                             (Heimlich Maneuver)
                                                                      │
                                                           Repeat cycle until cleared
                                                                      │
                                                           If patient becomes unconscious
                                                                      │
                                                                      ▼
                                                            INITIATE ADULT CPR (30:2)

Step-by-Step FBAO Protocols

1. Conscious Casualty with Severe Obstruction:
   • Stand slightly behind and to the side of the casualty. Support their chest with one hand and lean them forward.
   • Deliver 5 sharp back blows between the shoulder blades using the heel of your hand.
   • If unsuccessful, stand behind the casualty, wrap arms around the upper abdomen, make a fist with thumb side against the midline abdomen slightly above the navel (well below xiphoid process), grasp fist with other hand, and deliver 5 quick, inward-and-upward abdominal thrusts (Heimlich maneuver).
   • Special Exception: For pregnant mariners or markedly obese individuals, deliver chest thrusts over the center of the sternum instead of abdominal thrusts.
2. Unconscious Choking Casualty:
   • Carefully support the casualty to the deck in a supine position.
   • Activate the ship's emergency response team immediately.
   • Begin standard adult CPR starting with 30 chest compressions (compressions generate elevated intrathoracic pressure to expel the foreign body).
   • Open the airway, look into the mouth; if a foreign object is clearly visible, remove it with a finger sweep. NEVER perform a blind finger sweep, as this pushes foreign objects deeper into the larynx.
   • Attempt 2 rescue breaths; if chest does not rise, reposition airway and re-attempt breaths, then resume 30 compressions.

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5. The Lateral Recovery Position

The recovery position is the gold-standard position for an unconscious casualty who is breathing spontaneously and possesses an adequate pulse, provided there is no suspicion of cervical spine injury.

                       RECOVERY POSITION MECHANICS

     1. Near Arm: Placed at right angle (90°) to body, palm facing upward.
     2. Far Arm: Brought across chest, back of hand placed against opposite cheek.
     3. Far Leg: Bent at knee with foot flat on the deck.
     4. Roll: Pull bent knee to roll casualty toward rescuer onto their side.
     5. Stabilization: Position top leg at 90° angle at hip and knee; tilt head
        gently backward with mouth facing downward to allow drainage.

Physiological Benefits

• Prevents Airway Occlusion: Gravity keeps the relaxed tongue from falling backward against the hypopharynx.
• Aspiration Prevention: Saliva, mucus, blood, and vomitus drain freely out of the dependent mouth rather than into the trachea and lungs (preventing fatal chemical aspiration pneumonitis).
• Chest Expansion: The upper body is stabilized without putting direct weight on the thoracic cage, allowing unimpeded respiratory mechanics.

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6. Shipboard Mass Casualty Incident (MCI) Triage: The START Algorithm

A Mass Casualty Incident occurs when the number and severity of casualties exceed the immediate medical capabilities of the ship's crew (e.g., major engine room explosion, collision, cargo hold toxic gas release, galley flash fire). Rescuers must abandon standard individual care and apply START Triage (Simple Triage and Rapid Treatment) to maximize the number of survivors.

                       START TRIAGE DECISION TREE FLOWCHART

                              MASS CASUALTY INCIDENT
                                         │
                  "All crew who can walk, move to Station 1!"
                                         │
                    ┌────────────────────┴────────────────────┐
                   YES                                        NO
                    │                                         │
                    ▼                                         ▼
             GREEN (Minor)                             CHECK RESPIRATION
            Walking Wounded                                   │
                                      ┌───────────────────────┴───────────────────────┐
                                     NONE                                          PRESENT
                                      │                                               │
                               Open Airway                                     Rate > 30 bpm?
                                      │                                        ┌──────┴──────┐
                         ┌────────────┴────────────┐                          YES            NO
                      STILL NO                  BREATHING                      │             │
                         │                         │                           ▼             ▼
                         ▼                         ▼                    RED (Immediate) CHECK PERFUSION
                  BLACK (Expectant)         RED (Immediate)                           (Radial Pulse / CRT)
                                                                                             │
                                                                               ┌─────────────┴─────────────┐
                                                                           CRT > 2s /                 CRT ≤ 2s &
                                                                         No Radial Pulse            Radial Pulse
                                                                               │                           │
                                                                               ▼                           ▼
                                                                        RED (Immediate)              CHECK MENTAL
                                                                                                        STATUS
                                                                                                           │
                                                                                               ┌───────────┴───────────┐
                                                                                           Cannot Follow             Follows
                                                                                             Commands                Commands
                                                                                               │                        │
                                                                                               ▼                        ▼
                                                                                        RED (Immediate)          YELLOW (Delayed)

Comprehensive START Triage Classification Matrix

Exam Trap: In an active Mass Casualty Incident, CPR is NOT initiated for casualties tagged BLACK. When resources are overwhelmed, performing CPR on an apneic, pulseless casualty diverts vital personnel from salvageable RED casualties who will die without immediate airway positioning or hemorrhage control.