Royal Army College

Lesson Overview

Under pressure, a first-aider needs a drill, not a debate. The worst injuries kill in minutes, the scene is loud and frightening, and the calm, reasoning part of the mind is the first thing adrenaline shuts down. So you do not decide what to do at the casualty. You decide it now, and rehearse it until it almost runs itself.

This lesson gives you that drill: one ordered sequence for every casualty, so you always know what to do first, what next, and when to call for help. It covers your own safety and the scene, which come before treatment; the rapid first look that finds what is killing the casualty now; MARCH, the field order of priority that tackles the commonest quick killers first; the clinical method beneath it, ABCDE, with the secondary survey and SAMPLE history as the fuller assessment that follows; the recovery position for the unconscious casualty who is breathing; and the discipline of reassessing as you go.

Everything here is built so one person, with a basic kit and clear hands, can act usefully in the first minutes before better help arrives. This lesson is the spine of the course: every later lesson is one step of the sequence taught in full. Treat it as the map, and keep coming back to it.

By the end you will be able to explain why you deal with danger before you treat, carry out a primary survey, describe the MARCH order and say what you do at each letter and why it is ordered that way, show how ABCDE, the secondary survey, and the SAMPLE history fit beneath and after MARCH as one continuous sequence, place an unconscious breathing casualty in the recovery position in your own words, reassess a changing casualty, and explain why help is called early.

This is the knowledge layer of the course. The hands-on skills named here, opening an airway, the recovery position, packing a wound, taking a pulse, and the rest, are taught and certified in person under qualified supervision. You are a trained first responder, not a medic: you perform only what you are trained and currently authorised to do. The advanced or invasive procedures mentioned in passing, such as surgical airways, chest decompression, or any drug or fluid given by needle, are far beyond buddy aid and are learned, if ever, only in person under qualified medical supervision. The clinical detail here follows current accepted first-aid practice and is confirmed by the College's medical staff.

Key Terms

Scene safety: checking for and dealing with continuing danger before you approach or treat, so that you do not become a second casualty.
Primary survey: the rapid first assessment that finds and treats the immediate threats to life, in order.
MARCH: the field order of priority: Massive bleeding, Airway, Respiration, Circulation, Hypothermia and the head.
ABCDE: the clinical assessment method used everywhere for the acutely ill or injured: Airway, Breathing, Circulation, Disability, Exposure.
AVPU: a four-step scale for level of consciousness: Alert, responds to Voice, responds to Pain, Unresponsive.
Secondary survey: a careful head-to-toe examination, done once the immediate threats to life are controlled, to find injuries and signs missed in the first rush.
SAMPLE history: a structured way to gather the key background: Signs and symptoms, Allergies, Medications, Past medical history, Last oral intake, Events leading up to the illness or injury.
Recovery position: a stable position on the side that keeps an unconscious but breathing casualty's airway open and lets fluid drain from the mouth.
Reassessment: repeating the survey, because a casualty's condition changes.

Staying safe: yourself, the scene, the casualty

The first rule of the approach is the oldest: an injured rescuer helps no one and becomes a second person to be saved. Before you reach the casualty, stop at a safe distance, take one breath, and read the scene. Ask the question the panic in you will try to skip: what put this person here, and is it still here? A common and costly error is to run straight to a fallen comrade without asking what brought them down. If the cause is still present, a second casualty follows, and now there are two and one fewer rescuer.

Work the hazards in a quick, fixed scan so nothing is forgotten. Run your eyes outward from the casualty and name what you see: fire or smoke; an unstable building or wall; an electrical hazard, a live cable or a vehicle on a line; moving traffic; water, whether flood, river, or sea; a fall hazard, a slope, an edge, a height; toxic or irritant fumes; sharp debris and broken glass; and continuing violence, whether a fight, a crowd, or hostile fire. Listen as well as look, because some of these announce themselves by sound first. A useful order is to check, in turn, for danger from above, danger underfoot, and danger around you, then to ask what the casualty's body tells you about a hazard you cannot see: an awkward position suggesting a fall, a tool or wire in the hand suggesting electricity.

Having found the dangers, deal with the continuing ones before you treat. There are three ways, and you choose the safest that works. Best is to remove the danger from the casualty: switch off the power, beat out a small fire, stop the traffic with a marker and a person. Next is to remove the casualty from the danger: a short, controlled drag to cover or firm ground, accepting that moving an injured person is itself a risk and is done only when staying is the greater one. Last, when you can do neither yet, keep everyone back and call for those who can make the scene safe, the fire or rescue service, the power company, an armed party to win a firefight, before any kit is opened. Under hostile fire the first medical act may be no kit at all but to return fire, take cover, or put down smoke, because a casualty cannot be treated in the beaten zone and a dead rescuer treats no one.

Protect yourself from the casualty's blood and body fluids as a standing habit. Put on gloves before you touch a casualty; use eye protection where it is issued, because blood can spray; cover any cut on your own hands; and wash or sanitise as soon as the work allows. This is not delay for its own sake. It is what lets the care that follows happen at all, and a rescuer who skips it may carry an infection away from a scene that has already cost enough.

The primary survey and calling for help early

Once the scene is safe enough to work, carry out the primary survey: a fast, ordered hunt for what is killing the casualty in the next few minutes, treating each threat as you find it before moving on. This is not a leisurely examination, nor the careful head-to-toe check that comes later. It is a sweep of seconds for the handful of injuries that kill quickly, and it stops the moment you find one, because you fix that before looking further. The dangerous injuries, catastrophic bleeding and a blocked airway among them, kill in minutes, and they are precisely the injuries that simple, fast first aid can do most about. Spending those minutes well is the whole art of the first responder.

The survey opens with one quick judgement that sets everything after it: is the casualty conscious, and how deeply? Approach from the direction the casualty is facing, so they need not turn an injured neck to see you. Introduce yourself and ask a simple question: "Can you hear me? Open your eyes." If there is no reply, give a gentle but firm tap on the collarbones or shoulders and ask again. This is the start of the AVPU scale you meet again under Disability: a casualty who answers and looks at you is alert; one who responds only to a loud voice or touch is already a serious concern; one who does not respond at all is in immediate danger and is treated as most urgent. A casualty who can talk in clear sentences has, in that one fact, told you the airway is open, that they are breathing, and that enough blood is reaching the brain to think and speak: a great deal learned in a moment.

Call for help early, not late. As soon as you grasp that you have a seriously injured or ill casualty, get a message away, or send a named person to send it, while you keep working with your hands. Do not wait until you are free; you may never be free in time. A clear call says where you are as precisely as you can, what has happened, how many casualties and how serious, and what you need, then asks the sender to come back and confirm the message went and help is coming. Help is on its way from the first moment, not from the moment you happen to have a spare hand. You are the first link in a chain of care, not the last, and your job includes summoning the next link.

MARCH: the field order of priority

In the field the order of priority is held in one word, MARCH, so that under stress there is a single drill to follow rather than a choice to make. Each letter is a question, an action within your training, then a check before you move on. The order matters more than any single technique, because it spends your scarcest resource, the first few minutes, on the threats that take a life soonest.

M, Massive bleeding. Heavy bleeding from a limb or a major junction can drain a casualty in two to three minutes, faster than anything else you will meet, so it comes first, before even the airway. Sweep quickly for blood that is pumping, spurting, or pooling, running your gloved hands over places blood hides: the groin, the armpits, the back, under heavy clothing, where a serious bleed can soak inward and show little. The moment you find it, stop it by the means you have been trained to use: hard direct pressure straight onto the point of bleeding; packing the wound tightly with dressing or clean cloth and holding firm pressure; or a tourniquet high and tight on a bleeding limb, wound tight enough that the bleeding stops, the time noted. Stopping the bleed comes before everything else because the blood already lost cannot be put back by a first responder, and a casualty who bleeds out has no airway worth opening. Taught in full in Lesson 03, Catastrophic Bleeding.
A, Airway. Once the catastrophic bleeding is held, turn to the airway, because a blocked airway kills in not many more minutes than a haemorrhage. In an unconscious casualty lying on their back, the commonest obstruction is simply the tongue falling back against the throat. Open the airway with a gentle, deliberate movement, a head-tilt and chin-lift where no neck injury is suspected, or a jaw thrust where it is, and look in the mouth for an obvious blockage: vomit, blood, a broken tooth. Clear only what you can see and reach. Then keep it open: hold the position, or place a breathing casualty in the recovery position taught below. Taught in full in Lesson 04, Airway and Breathing.
R, Respiration (breathing). A clear airway is no use if the casualty is not breathing through it, so next confirm that air is actually moving. With the airway held open, put your cheek close to the mouth and look along the chest: look for the chest rising and falling, listen for breath, feel for air on your cheek, for up to ten seconds. Judge not only whether the casualty breathes but whether the breathing is adequate, neither far too slow nor gasping and far too fast, and whether both sides of the chest rise together. If the casualty is not breathing normally, this is a collapse that needs the resuscitation taught in person, and help must be screaming in by now. Look and feel here too for a serious chest injury, an open or sucking wound, that stops the lungs working, and treat it within your training. Taught in full in Lesson 04, Airway and Breathing.
C, Circulation. Having dealt with the obvious heavy bleeding under M, now check the circulation as a whole and hunt for bleeding you may have missed. Look at the skin: is it pale, grey, cold, or sweating, the early face of shock? Feel a pulse where you have been taught to, at the wrist or the neck, and note whether it is present, fast and thready, or strong and steady. Note the casualty's alertness, because a brain starved of blood grows confused, anxious, then drowsy. Go looking again for blood, sweeping under clothing, along the limbs, and especially down the back and buttocks where a casualty lying still can pool a dangerous amount unseen. Stop any further bleeding you find and treat for shock by laying the casualty down, keeping them still, and keeping them warm. Taught in full in Lesson 05, Circulation, Shock, and Assessing the Casualty.
H, Hypothermia and the head. Last in the field sequence, but never optional, guard the casualty's temperature and watch their head. An injured casualty loses heat fast, even in mild weather, because injury, blood loss, shock, and lying still all rob the body of warmth; and cold makes bleeding worse by stopping blood from clotting, deepens shock, and slows recovery. So insulate the casualty from the ground, which steals heat quickest, and cover them over, getting something both under and over them. The same step is the moment to watch the head: keep tracking the level of consciousness, because a head injury can worsen quietly over many minutes, a casualty who was talking becoming drowsy or confused. Keeping the casualty warm is taught with the environmental injuries in Lesson 06, Cold, Heat, Burns, and Drowning; recognising and managing the deteriorating, head-injured, or shocked casualty runs across Lessons 05 and 06.

The order is the point. It puts the threats that kill quickest at the front, so the few minutes you have are spent on what will save the casualty's life, not on a minor wound while a major one bleeds out, or a careful examination while the casualty stops breathing. Run the letters in order, deal with what you find before you move on, and you will rarely do the wrong thing first.

The whole drill in one picture:

flowchart TD
    S["Scene safe? Protect yourself. Call for help early"] --> CON["Conscious? Check response (AVPU)"]
    CON --> M
    M["M: Massive bleeding<br/>Control now by pressure, packing, or tourniquet"] --> A
    A["A: Airway<br/>Open and clear it; position to keep it open"] --> R
    R["R: Respiration<br/>Look, listen, feel; treat chest injuries"] --> C
    C["C: Circulation<br/>Treat for shock; find hidden bleeding"] --> H
    H["H: Hypothermia and head<br/>Insulate and cover; watch consciousness"] --> RE
    RE{"Reassess often, and after any move"} -->|"something has changed"| M
    RE -->|"stable"| HO["Hand on, with fuller ABCDE, a secondary survey, and a SAMPLE history"]

At each step, deal with what you find before you move on, and keep coming back to the start.

ABCDE, the secondary survey, and SAMPLE: the same sequence, in more detail

MARCH and ABCDE are not two rival systems to choose between. They are one sequence at two levels of detail, and the great mistake of the half-trained is to treat them as competitors and freeze deciding which to use. MARCH carries the dying casualty through the first minutes, leading with massive bleeding because that is the commonest rapid killer in the field. ABCDE is the fuller clinical assessment, used everywhere for the acutely ill or injured, that you work through once the immediate killers are in hand and keep returning to.

The letters line up almost exactly. The A, B, and C of ABCDE are the same Airway, Breathing, and Circulation you met in MARCH, now assessed more thoroughly and calmly because the worst is held. Where MARCH asked "is the airway open?", ABCDE asks "is the airway secure, and will it stay open while I attend to other things?" Where MARCH asked "is the casualty breathing?", ABCDE looks at the rate, the depth, the symmetry of the chest, and any sound. Where MARCH said "stop the bleeding and treat for shock", ABCDE re-checks pulse, skin, and alertness and looks once more for hidden blood. ABCDE then adds two letters that MARCH folds into its "H":

D, Disability. A quick check of the brain and nervous system. Assess the level of consciousness with the AVPU scale: Alert, awake and aware; responds to Voice, reacts only when you speak; responds to Pain, reacts only to a firm, fair stimulus such as a pinch to the shoulder; Unresponsive, no reaction at all. Note where the casualty sits and, above all, whether they are moving down the scale over time, the single clearest warning of a worsening head injury or deepening shock. Then look at the pupils, the black centres of the eyes: they should be equal in size and shrink briskly when light reaches them. Pupils that are unequal, very large, very small, or slow to react can signal a serious head injury and are reported to those who take over. Finish by checking that the casualty can move and feel their fingers and toes, which begins to test the spine.
E, Exposure. Examine the whole body for injuries you have not yet found, then cover the casualty again and keep them warm. Exposure does not mean stripping a casualty and leaving them bare. It means uncovering only what you must to see and reach an injury, looking, and covering again at once, working in sections so the casualty is never wholly exposed. Cut clothing rather than drag it over an injured limb where you can. Protect the casualty from cold, wind, wet, and the ground throughout, and guard their dignity, because a casualty is a person before they are a problem: explain what you are doing even if they seem not to hear, screen them from onlookers, and expose no more of the body than the injury demands.

If you remember that MARCH simply moves massive bleeding to the front and is otherwise the familiar A-B-C-D-E, the two stop competing in your mind and become one drill, run at speed in the first minutes and again, more fully, once the casualty is stable.

Once the immediate threats to life are controlled, carry out the secondary survey: a careful head-to-toe examination to find the injuries and signs the first rush missed. Where the primary survey hunted only for what kills in minutes, the secondary survey is methodical and complete, done in a fixed order so nothing is skipped. Work from the head down, looking and gently feeling: the scalp and face for wounds, swelling, or blood or fluid from the ears or nose; the neck, without moving it; the collarbones and shoulders; the chest, feeling both sides move as the casualty breathes; the abdomen, gently, for rigidity or tenderness; the pelvis, pressed gently, never rocked hard; each arm and leg in turn, looking for deformity, swelling, wounds, and checking movement, feeling, and a pulse beyond any injury; and finally, with help and care, the back, by a controlled roll if it is safe. Feel inside your gloves for the warm wetness of blood you cannot see, and look at your hands after each part. You are building the full picture the first frantic survey had no time for.

Alongside the secondary survey, gather the background that shapes what comes next, using the SAMPLE history. Ask, of the casualty if they can answer, or of family, comrades, or bystanders if they cannot: Signs and symptoms (what is wrong, what you can see, and what the casualty feels, such as pain, breathlessness, or dizziness); Allergies (which may explain a reaction now and which matter for any later treatment by others); Medications they take, prescribed or otherwise, which hint at conditions and interactions; Past medical history (illnesses, operations, anything they are being treated for); Last oral intake (when they last ate or drank, which matters before any surgery); and Events leading up to the illness or injury (what happened, the mechanism, the height of a fall, the speed of a vehicle, how long the casualty has been down). Write it down or hold it ready, because you will hand it on, and the person who treats the casualty next will be glad of every word. MARCH and the primary survey keep the casualty alive; ABCDE, the secondary survey, and SAMPLE build the fuller picture you hand on to those who can do more.

The recovery position: the unconscious casualty who is breathing

There is one casualty for whom a single positioning skill does much of the work of keeping the airway open: the casualty who is unconscious but breathing normally, and who has no injury that forbids being turned. Left flat on the back, such a casualty is in danger: the tongue can fall against the throat and, worse, vomit or blood can pool in the mouth and be drawn into the lungs. Turned onto the side, the airway falls open and fluid drains away from it. This is the recovery position, one of the most useful things a first responder can do with their hands.

Place it only when the casualty is breathing normally and you do not need them on their back for resuscitation, and with care if a spinal injury is possible, where keeping the airway clear still wins but the move is made slowly and, ideally, with help to support the head. The principle to carry away: any stable position on the side that keeps the airway open and lets fluid drain is acceptable; the recovery position is the safe, repeatable way to get there. Learn the movement in person until it is smooth; the sequence below is the shape of it so the words make sense on the day.

   Placing an unconscious, breathing casualty in the recovery position
   (casualty on their back; you kneel at their side)

   1. Remove spectacles and any bulky objects from the pockets.
   2. Straighten both legs. Place the near arm out at a right angle to the
      body, elbow bent, palm turned up.
   3. Bring the far arm across the chest and hold the back of that hand
      against the casualty's near cheek; keep it there.
   4. With your other hand, pull up the far knee so the foot stays flat on
      the ground.
   5. Keeping the hand pressed to the cheek, pull on the far knee to roll
      the casualty towards you, onto their side.
   6. Adjust the upper leg so hip and knee are bent at right angles, which
      stops them rolling further. Tilt the head back gently so the airway
      stays open, and check the mouth can drain.
   7. Stay with the casualty. Check breathing constantly, keep them warm,
      and be ready to roll them back at once if breathing stops.

A casualty left in the recovery position for a long time should be turned to the other side after a while to spare the lower arm, but never lose sight of the airway and breathing while you do it. The whole purpose is a clear airway and a constant watch, not a tidy posture.

A clean MARCH-then-ABCDE algorithm

The Mermaid picture above shows the field drill; the lines below set the field drill and the fuller assessment side by side, so you can see they are one sequence read at two depths. Trace it top to bottom, and remember the arrow back to the start is as important as any step in it.

   STAYING SAFE        Scene safe? Remove or avoid danger. Gloves on.
        |              Send for help now. Check response (AVPU).
        v
   PRIMARY SURVEY (MARCH) - fast, fix-as-you-find, seconds not minutes
        |
        +--> M  Massive bleeding ...... pressure / packing / tourniquet   [L03]
        |        stop it before you move on
        +--> A  Airway ................ open it; clear what you can see    [L04]
        |        keep it open (recovery position if breathing)
        +--> R  Respiration ........... look, listen, feel; chest injury  [L04]
        |        is breathing present and adequate?
        +--> C  Circulation ........... skin, pulse, alertness; hunt for  [L05]
        |        hidden blood; treat for shock
        +--> H  Hypothermia & head .... insulate and cover; track AVPU    [L05-06]
        |
        v
   FULLER ASSESSMENT (ABCDE) - calmer, once life threats are held
        |
        +--> A  Airway ................ secure and staying open?
        +--> B  Breathing ............. rate, depth, both sides equal, sound
        +--> C  Circulation ........... re-check pulse, skin, alertness, bleeding
        +--> D  Disability ............ AVPU; pupils equal and reacting; move/feel limbs
        +--> E  Exposure .............. examine in sections, then cover and keep warm
        |
        v
   SECONDARY SURVEY + SAMPLE   head-to-toe; S-A-M-P-L-E history
        |
        v
   REASSESS  <-----------------------------------------+
   work the whole sequence again, and after any move.  |
   Anything changed? Go back to M. -------------------- +

Reassessing the casualty

A casualty is not a fixed problem solved once and filed away. A tourniquet can slip or loosen when the casualty is moved or warms up; a wound can soak through a dressing that looked secure; breathing can deteriorate as a chest injury worsens; the airway can block in a casualty whose conscious level is falling; and shock can creep up quietly as blood is lost inside the body where you cannot see it. The casualty you stabilised is not the casualty you will have in ten minutes unless you keep watching.

So the sequence is not run once. Go back to the start and run it again, every few minutes, after any move, and immediately if anything looks worse, asking at each step whether something has changed. Reassessment is not vague worry; it is the same ordered check done again: is the bleeding still controlled, the airway still open, the breathing still adequate, the pulse and skin and alertness holding, the casualty still warm, the level of consciousness steady on the AVPU scale or sliding? Watch the trend over time, because the direction a casualty is moving tells you more than any single reading. Continuous reassessment, not a single inspection, is what catches the casualty who is quietly getting worse in time to act, and you keep doing it right up until you hand over.

Over the whole of this drill, from the first glance at the scene to the handover, sits the law and conscience of the Army: you give humane care to everyone who needs it, friend, civilian, and former enemy alike, by their need and by nothing else, and you treat the casualty with dignity throughout, living or dead. The sequence keeps the casualty alive; the principle keeps the act worthy of the Army that taught it.

In Practice: One Drill at Every Casualty

Picture three very different scenes on a single rotation. A soldier is caught by a blast on a training area and lies still in churned ground. A national is pulled from a car that has gone off a flooded road. An elderly person collapses on a cold doorstep during a winter welfare round. The injuries could hardly differ more, yet your first moves are identical in each, which is the whole reason the drill exists.

In each, you stop short and read the scene before going in. At the blast, you ask whether there is a second device or unexploded ordnance and wait for the ground to be cleared rather than walk onto it. At the car, you judge the water and the slope before stepping in, because a rescuer swept off their feet helps no one. At the doorstep, the danger is the cold itself and a hard, icy step. You protect yourself, get gloves on, and get a message away early, sending a named bystander to call and come back. Then you run the one sequence. You check the casualty's response and find, in each case, how deeply they are conscious. You sweep for and stop any massive bleeding, the soldier's torn leg first of all. You open and check the airway, and at the car you place the breathing but unconscious casualty on their side so the water drains from their mouth. You look, listen, and feel for breathing. You check the circulation, feel the skin and pulse, and hunt under clothing and along the back for blood you have not yet seen. You insulate the elderly person from that freezing step and cover them, and you watch each casualty's level of consciousness for any slide. Then, with the worst held, you work through ABCDE more fully, run a head-to-toe secondary survey, and take a SAMPLE history from whoever can give it. You give only the care you are trained and authorised to give, you reassess as you go, and you treat each person with dignity throughout. Because the drill is always the same, you do not have to invent it under stress; you simply begin.

Check Your Understanding

Why does the systematic approach put your own safety and the safety of the scene before treating the casualty? Give an example of a "continuing danger", and describe the three ways you might deal with it.
State the MARCH order in full, and for each letter say in one line what you actually do. Explain why massive bleeding comes before airway, and airway before breathing.
The course insists that MARCH and ABCDE are "one sequence, not two." Explain how ABCDE, the secondary survey, and the SAMPLE history fit beneath and after MARCH, and describe when and how you would place a casualty in the recovery position.

Reflection (write a short paragraph): Think about why a single, memorised drill helps a first-aider act rather than freeze when the moment comes, and why a changing casualty must be reassessed rather than checked once. What is the cost of running the steps in the wrong order, or of treating MARCH and ABCDE as rival schemes to choose between? What does that suggest about how you should rehearse this sequence, and the recovery position within it, before you ever meet a real casualty?

Summary

Deal with continuing danger and protect yourself before you treat; read the scene in a fixed scan, and remove the danger, remove the casualty, or hold and call. An injured rescuer becomes a second casualty.
Carry out a rapid primary survey to find and treat the immediate threats to life in order; check the casualty's response on the AVPU scale, and call for help early so the chain of care is moving from the first moment.
MARCH is the field order of priority, Massive bleeding, Airway, Respiration, Circulation, Hypothermia and the head, and it puts the commonest quick killers first. At each letter, do the most you are trained to do, then check before moving on.
ABCDE (Airway, Breathing, Circulation, Disability via AVPU and pupils, Exposure meaning examine then cover and keep warm) is the fuller clinical method beneath MARCH; the secondary survey examines head to toe and the SAMPLE history gathers the background. They are one continuous sequence, not a competing scheme.
Place an unconscious, breathing casualty in the recovery position to keep the airway open and let fluid drain, and stay with them; reassess every casualty repeatedly, because their condition changes; give only the care you are trained and authorised to give; and give humane care, with dignity, to everyone by their need alone.

The Systematic Approach: Staying Safe, MARCH, and ABCDE