Critical Systems
What is the circulation of oxygenated blood under pressure through the vasculature to supply cells, tissues, organs.
Perfusion
Name two primary functions of the respiratory system.
Oxygenation;
Regulation of pH.
What are the three main components of the circulatory system?
Heart;
vessels;
blood.
What does ACVPU stand for? Give a brief practical note on using it.
A—Awake; C—Confused; V—Verbal; P—Pain; U—Unresponsive.
Practical: quick, repeatable scale to track changes and triage.
What does the mnemonic "SCAN" stand for in generic respiratory treatment?
S—Support natural respiratory effort;
C—Calm & Reassure;
A—Assess the patient;
N—Normoxia (target).
List the three types circulations and give one clinical implication of each for emergency care.
Systemic: delivers O2 to tissues;
Pulmonary: oxygenates blood;
Coronary: supplies myocardium.
Identify three anatomic structures of the upper airway that are critical to assess for obstruction.
Tongue,
epiglottis,
larynx
State the normal percentage breakdown of blood components (plasma, buffy coat, red cells).
Plasma 55%;
Buffy coat <1%;
RBCs 45%.
List three functions of the frontal lobe and two functions of the brainstem relevant to pre-hospital assessment.
Frontal lobe: problem solving, judgment, expressive speech (among others).
Brainstem: breathing, heart rate/vascular control, consciousness/alertness.
Give three general first-aid actions recommended for chest wall trauma (any type).
Humidified oxygen, analgesia, evacuation/definitive care; consider chest seal for open pneumothorax and PPV if indicated (except avoid PPV in closed pneumothorax).
Describe the three major components that must be functioning to maintain oxygenation and ventilation
Upper airway,
Lower airway (including bronchi/alveoli),
Chest wall/diaphragm + neurological drive (respiratory drive)
Compare the typical features (signs/symptoms) of respiratory distress vs respiratory failure vs respiratory arrest per the document.
Respiratory distress: difficulty breathing, short sentences, A on ACVPU but distressed.
Respiratory failure: one–two words, lethargic trending toward V/P.
Respiratory arrest: not breathing.
Differentiate compensated vs decompensated hypovolaemic shock in terms of blood pressure, heart rate, urine output, and level of consciousness.
Compensated: BP ≈ normal, HR increased, urine output mildly reduced, LOC preserved.
Decompensated: BP decreased, HR very high, urine output very low, LOC reduced.
Name the potential causes of decreased nervous drive (brain failure).
P—Pressure; O—Oxygen; S—Salts; T—Temperature; H—Hypovolaemia; A—Altitude; S—Sugar; T—Toxins; E—Electricity
List the three ‘C’s for seizure management and state the time threshold for calling emergency services.
Calm; Cushion; Call — call ambulance if seizure lasts longer than five minutes.
Explain how you would use ACVPU to prioritize a patient in a multi-casualty incident.
Use ACVPU to rapidly categorize mental status:
A (awake & oriented) lowest priority;
C/V/P/U escalate urgency—unresponsive or
P/U get immediate airway/ventilation support.
For a patient with suspected closed pneumothorax: list four signs/symptoms and four management actions; highlight one intervention to avoid.
Signs: sharp stabbing chest pain, SOB, rapid shallow breathing, cyanosis, fatigue/anxiety.
Management: humidified oxygen, analgesia, evacuation.
Avoid PPV (for closed pneumothorax)
For distributive shock (e.g., anaphylaxis), name the pathophysiology, at least three S/Sx you might see, and the immediate field treatment
Pathophysiology: vasodilation & capillary permeability. S/Sx: hypotension, warm skin (early), tachycardia, signs of infection/anaphylaxis (urticaria, swelling). Treatment: adrenaline for anaphylaxis, vasoconstrictors/antibiotics if authorised, volume replacement, evacuation.
Outline early and late signs of increased intracranial pressure and two immediate field actions to take.
Early ICP: mental status changes, severe headache, persistent vomiting. Late: decreased to V/P/U, seizures, posturing, dilated pupils, major vital sign changes.
Actions: protect airway, maintain normothermia, urgent neurosurgical evacuation, maintain hydration/caloric intake if delay expected.
For exercise-associated hyponatremia, describe the mechanism and three key signs/symptoms that differentiate it from simple dehydration.
Mechanism: excessive fluid intake dilutes serum sodium.
Signs: altered mental status/lethargy/confusion, nausea/headache/seizures, near-normal urine output and core temperature (distinguish from dehydration where urine output usually low, core temp altered).
A patient presents with altered mental status and hypotension after severe vomiting and diarrhea. State the most likely category of shock and three immediate field management steps
Hypovolaemic shock likely. I
mmediate steps: stop fluid loss/bleeding, replace volume as available (IV/ORS), maintain body temperature, urgent evacuation.
Describe flail chest: mechanism (how defined), three clinical signs, and the prioritized field management steps.
Flail chest = three+ ribs fractured in two+ places producing paradoxical chest wall movement.
Signs: paradoxical movement, crepitus, severe pain, seatbelt bruising (MOI).
Management: humidified O2, analgesia, consider PPV if respiratory compromise, urgent evacuation.
A trauma patient with hypotension, distended neck veins, and unilateral absent breath sounds—identify the likely type of shock and describe the initial field approach.
Likely obstructive shock (e.g., tension pneumothorax). Initial approach: high-flow O2, decompress/treat cause if trained and indicated, urgent evacuation, BLS as needed.
For traumatic brain injury in the field: give an evidence-based plan for observation/management, including guidance about monitoring, activity, and evacuation.
Field plan: secure airway & oxygenation; prevent hypotension (maintain perfusion); monitor for increasing ICP (frequent ACVPU, pupils, vitals) for 24+ hours; arrange urgent evacuation to neurosurgical-capable facility; allow supervised sleep but not alone; anticipate vomiting and airway protection.
Create a concise evacuation justification (3–4 bullet points) you would give when requesting urgent ALS transfer for a patient with suspected increased ICP.
(1) Suspected raised ICP with progressive LOC change (2) Need for neurosurgical assessment/intervention; (3) Risk of airway compromise/vomiting requiring advanced airway; (4) Need for CT imaging and definitive critical care—recommend urgent ALS transport.