Opening

Rapid response call, 0200

• Ward 7, bed 12: “BP 78/40”
• You’re the first doctor there

Question

What are the first three things you’d do when you walk into the room?

Opening

What if the BP was 93/60?

• Does that change anything?
• What if the patient is 22? What if they’re 85?

Question

Is 93/60 “normal”? What else would you want to know?

Opening

By the end of this session you should be able to

• Recognise shock before the blood pressure falls
• Classify shock by mechanism using one equation
• Use a structured approach to the undifferentiated shocked patient: resuscitate while you work out the type
• Tell the types apart at the bedside, and know when to escalate

The Framework

What is shock?

• Inadequate tissue oxygen delivery: $D{O}_2<\dot{V}{O}_2$
• Almost always mediated by low blood pressure, but hypotension is the consequence, not the definition

The Framework

One equation

• $\text{CO}=\text{HR}\times \text{SV}$
• SV depends on preload, contractility and afterload

Question

If perfusion pressure is low, which terms could be responsible?

The Framework

Where it can fail

The Framework

Four mechanisms

The Framework

A better mnemonic: PROVED?

• Pump
• Rhythm
• Obstructive
• Volume
• Endocrine
• Distributive
• ? Is it real?

Recognising Shock

Shock is a clinical diagnosis

• Haemodynamics: MAP < 65 or a big drop from baseline, shock index (HR/SBP) > 0.8
• Skin: cool knees and hands, mottling, CRT > 5 s
• Kidneys: urine output < 0.5 mL/kg/h
• Brain: agitation → delirium → drowsiness
• Blood: ↑ lactate, ↓ HCO₃⁻

Recognising Shock

Look at the knees

Contou D, de Prost N. Skin Mottling. N Engl J Med 2016;375:2187. doi:10.1056/NEJMicm1602055

Question

What’s the difference between A and B?

The Approach

Resuscitate while you differentiate

1. Recognise it’s shock and call for help
2. Primary survey: ABC, monitoring, exclude the immediate killers
3. Differentiate at the bedside: peripheries, heart rate, filling (PUMPS), POCUS
4. Empirical resuscitation: fluid challenge, vasopressor, specific treatment
5. Secondary survey: history, examination and investigations for the cause
6. Reassess and escalate

The Approach

The primary survey

• Call for senior help early
• A, B, C with monitoring on
• Exclude the things that kill quickly: tension pneumothorax, massive haemothorax, external haemorrhage, anaphylaxis, tamponade, massive PE
• IV access, bloods including cultures, ABG/VBG with lactate, 12-lead ECG
• Peri-arrest? Adrenaline 0.1 mg boluses to buy time while setting up an infusion

The Approach

Three bedside questions

• Peripheries: warm or cold? (SVR)
• Heart rate: fast, slow or normal?
• Filling: full or empty?

The Approach

Assessing filling: PUMPS

• Peripheral perfusion: capillary refill time, systolic BP, pulse pressure
• Urine output
• Mucous membranes and skin turgor
• Pressure in the neck: JVP
• Signs of volume overload: peripheral oedema, hepatojugular reflux, S3 gallop, lung crackles

Question

Which of these can you check in the first two minutes?

The Approach

History that points to the type

Case 1: Mrs P

Mrs P, 78

Case 1: Mrs P

Warm, fast, empty: distributive

• Peripheries: warm, CRT 2 s → low SVR
• Heart rate: 118 → fast
• Filling (PUMPS): dry mucous membranes, JVP not visible, no signs of overload, urine output ≈ 0.17 mL/kg/h → empty
• With a fever and a known UTI, this is septic shock until proven otherwise

Case 1: Mrs P

Sepsis and septic shock (Sepsis-3)

• Sepsis: life-threatening organ dysfunction due to a dysregulated host response to infection
  • Organ dysfunction = increase in SOFA score ≥ 2
• Septic shock: sepsis plus both
  • Hypotension requiring vasopressors
  • Lactate > 2 mmol/L

Case 1: Mrs P

Fluids, done properly

• Give as a challenge: 250–500 mL over 10–15 min, then reassess
• 30 mL/kg within the first 3 hours for sepsis
• Balanced crystalloid (Hartmann’s, Plasma-Lyte) in most patients

Question

“Don’t we always give normal saline?”

Case 1: Mrs P

Saline or balanced crystalloid?

• Balanced crystalloid is generally preferred in septic shock
  • A conditional recommendation from the Surviving Sepsis Campaign, based on low quality evidence
• Normal saline is preferred in:
  • Hypochloraemic alkalosis (e.g. vomiting, NGT losses)
  • Hyperkalaemia
  • Traumatic brain injury
  • Meningitis

Case 1: Mrs P

We’re bad at predicting who needs fluid

• Being fluid responsive doesn’t mean the patient needs fluid
• MAP and urine output lag behind and don’t reliably predict fluid responsiveness
• So give a bolus, then ask whether the patient actually got better:
  • Capillary refill time and mottling
  • Urine output
  • Repeat lactate at 2 hours (aim for > 10% clearance)
  • Mental state

Case 1: Mrs P

An hour later: 2 L in, MAP 58

Case 1: Mrs P

Noradrenaline running

Case 2: Mr T

Mr T, 34

Case 2: Mr T

Cold, fast, empty: hypovolaemic

• Peripheries: cool to the knees, CRT 4 s → vasoconstricted
• Heart rate: 124 → fast
• Filling (PUMPS): narrow pulse pressure, JVP not visible → empty
• In trauma, that’s haemorrhage until proven otherwise

Case 2: Mr T

The shock index

• 0.8 is elevated

• Mr T: 124 ÷ 108 ≈ 1.15
• Also look at his pulse pressure: 108 − 84 = 24 mmHg, which is narrow

Case 2: Mr T

Where’s the blood? SCALPeR

• Scalp / Street
• Chest
• Abdomen
• Long bones
• Pelvis
• Retroperitoneum

Question

How would you look for each at the bedside in the first 10 minutes?

Case 2: Mr T

Looking for it at the bedside

Case 2: Mr T

Managing haemorrhagic shock

• Stop the bleeding: that’s the definitive treatment
• Permissive hypotension: target SBP 80–90 until bleeding is controlled
  • Not in TBI: keep MAP ≥ 80
• Activate the major haemorrhage protocol
• Tranexamic acid within 3 hours: 1 g over 10 min, then 1 g over 8 h
• Noradrenaline only if restricted fluid can’t hold the target

Case 2: Mr T

The major haemorrhage protocol

• Blood, not crystalloid
• RBC:FFP:PLT no lower than 2:1:1
  • At least 1 FFP for every 2 RBC
  • At least 1 adult unit of platelets for every 8 RBC
• Fibrinogen 3–4 g (cryoprecipitate or concentrate)
• Keep warm (≥ 35 °C), calcium up (iCa ≥ 1), and recheck bloods every 4 units

Case 3: Mr K

Mr K, 66

Case 3: Mr K

Cold, fast, full

• Peripheries: cold, mottled → vasoconstricted, low output
• Heart rate: 108 → fast
• Filling (PUMPS): JVP up, crackles, oedema → full
• With chest pain and ST elevation, cardiogenic shock is most likely…
• …but obstructive shock is cold and full too

Case 3: Mr K

Probably not

Only give fluid if all of these are true:

• End-organ perfusion is inadequate
• No pulmonary congestion (e.g. no B-lines)
• The overall picture suggests true hypovolaemia
• Dynamic indices suggest he’s fluid responsive

Case 3: Mr K

Cold and wet

Case 3: Mr K

Managing cardiogenic shock

• 12-lead ECG and POCUS early
• Support the lungs: CPAP/BiPAP
• Noradrenaline first to restore MAP, and keep an eye on the DBP (≥ 60 mmHg) for coronary perfusion
• Then dobutamine if still poorly perfused (cold, mottled)
• Adrenaline alone is reasonable as a short-term bridge
• Treat the cause: revascularisation for ACS
• Escalate early: ICU and cardiology

Putting It Together

Same three questions, different answers

Putting It Together

Don’t miss these

Wrap-Up

Your first 15 minutes

1. Recognise it and call for help
2. Primary survey: ABC, monitoring, access, VBG with lactate, ECG
3. Differentiate: peripheries, heart rate, filling (PUMPS), POCUS
4. Resuscitate: fluid challenge, pressor, inotrope, blood, or fix the obstruction
5. Secondary survey: history, examination, investigations
6. Reassess, and escalate

Wrap-Up

Take-home

• Shock is a failure of oxygen delivery; BP falls late
• $\text{MAP}-\text{CVP}=\text{CO}\times \text{SVR}$ tells you where to look
• Warm vs cold, fast vs slow, full vs empty (PUMPS)
• Resuscitate while you differentiate, and reassess after everything you give
• More than one type can co-exist (e.g. sepsis + hypovolaemia)
• Full notes: Shock

Wrap-Up

Sources: guidelines and trials

• Singer M, et al. The Third International Consensus Definitions for Sepsis and Septic Shock (Sepsis-3). JAMA. 2016;315(8):801–10
• Surviving Sepsis Campaign: International Guidelines for Management of Sepsis and Septic Shock 2026. Crit Care Med. 2026
• Asfar P, et al. High versus low blood-pressure target in patients with septic shock (SEPSISPAM). N Engl J Med. 2014;370:1583–93
• ARISE FLUIDS Investigators. Vasopressors or fluids in early septic shock. N Engl J Med. 2026. doi:10.1056/NEJMoa2516225
• National Blood Authority. Patient blood management guideline for adults with critical bleeding, v2.0. 2025
• Rossaint R, et al. The European guideline on management of major bleeding and coagulopathy following trauma: sixth edition. Crit Care. 2023;27:80. doi:10.1186/s13054-023-04327-7
• CRASH-2 trial collaborators. Effects of tranexamic acid in trauma patients with significant haemorrhage. Lancet. 2010;376:23–32. doi:10.1016/S0140-6736(10)60835-5
• NSW Agency for Clinical Innovation. Management of cardiogenic shock

Wrap-Up

Sources: reviews and further reading

• Thiele H, Hassager C. Cardiogenic shock. N Engl J Med. 2025;394(1):62–77. doi:10.1056/NEJMra2312086
• Puttur Rajkumar K, et al. Blood pressure goals in critically ill patients. Methodist DeBakey Cardiovasc J. 2023;19(4):24. doi:10.14797/mdcvj.1260
• Queensland Spinal Cord Injuries Service. Spinal and neurogenic shock
• Contou D, de Prost N. Skin mottling. N Engl J Med. 2016;375:2187. doi:10.1056/NEJMicm1602055 (mottling image)
• The POCUS Atlas: RUSH, undifferentiated hypotension
• Deranged Physiology: Approach to the undifferentiated shock patient
• LITFL: Shock · ICU One Pager: Undifferentiated shock
• Figures drawn for this tutorial; full notes and references in Shock