Acute Medicine: Shock, sepsis and critical illness

🩺 Shock, sepsis and critical illness. Shock means the tissues aren't getting enough oxygen -and it kills quickly unless the cause is found and fixed. Sepsis is the commonest cause of shock on medical wards, causing about 48,000 deaths a year in the UK; every hour's delay in antibiotics for septic shock increases mortality. Infection-specific detail is in the Infectious Diseases chapter on Sepsis; trauma haemorrhage is on the Major Trauma page.
Your four questions for every shocked patient: Is the patient shocked (BP, lactate, perfusion, urine output, mental state)? What type of shock is it -hypovolaemic, distributive, cardiogenic or obstructive? What treatment is needed in the next hour (fluids, antibiotics, blood, vasopressors, source control)? Does the patient need critical care -and is that within their ceiling of care?

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What Is Shock?

• Shock -a state of inadequate tissue perfusion and oxygen delivery, leading to cellular dysfunction and organ failure.
• Oxygen delivery = cardiac output × arterial oxygen content (Hb × saturation); cardiac output = heart rate × stroke volume; blood pressure = cardiac output × systemic vascular resistance.
• Hypotension is a late sign -compensation (tachycardia, vasoconstriction) maintains BP until a lot of volume or function is lost, especially in young people.
• Signs of shock:
  • Tachycardia (may be absent with beta-blockers, pacemakers, hypothermia, older people).
  • Hypotension -systolic under 90 mmHg, MAP under 65 mmHg, or a fall over 40 mmHg from baseline.
  • Poor peripheral perfusion -cold, mottled skin, prolonged capillary refill (warm peripheries early in distributive shock).
  • Reduced urine output -under 0.5 mL/kg/hour.
  • Altered mental state -anxiety, confusion, drowsiness.
  • Raised lactate -over 2 mmol/L (over 4 = severe).
  • Tachypnoea (compensating for metabolic acidosis).
• Mean arterial pressure (MAP) = diastolic + one-third of (systolic − diastolic); target MAP 65 mmHg or more for most patients (higher in some chronic hypertension).

Types of Shock

Type	Causes	Clinical clues	Main treatment
Hypovolaemic	Haemorrhage (GI bleed, AAA, trauma, ectopic), dehydration (vomiting, diarrhoea, DKA, burns, high stoma output)	Cold, pale, flat neck veins, low JVP	Stop bleeding, fluids, blood
Distributive	Sepsis (commonest), anaphylaxis, neurogenic (spinal cord injury), adrenal crisis, liver failure, drugs	Warm peripheries early, bounding pulse, low diastolic BP	Fluids, vasopressors, treat cause (antibiotics, adrenaline, hydrocortisone)
Cardiogenic	MI, arrhythmias, myocarditis, acute valve failure (papillary muscle rupture), end-stage heart failure, drug toxicity	Cold, raised JVP, pulmonary oedema, ECG changes	Revascularisation, inotropes, treat arrhythmia, mechanical support
Obstructive	Massive PE, tension pneumothorax, cardiac tamponade	Raised JVP, clear chest (PE, tamponade), absent breath sounds (pneumothorax)	Relieve the obstruction -thrombolysis, decompression, pericardiocentesis

• Mixed shock is common -e.g. sepsis with dehydration and septic cardiomyopathy.
• Neurogenic shock -loss of sympathetic tone after cord injury above T6 -hypotension with bradycardia and warm skin.
• Endocrine causes -adrenal crisis (hyponatraemia, hyperkalaemia, steroid use), myxoedema coma, thyroid storm.

Assessing the Shocked Patient

• ABCDE with high-flow oxygen, two large-bore cannulas, monitoring, and a senior early.
• Key bedside measurements -HR, BP (and MAP), capillary refill, skin temperature and mottling, JVP, urine output (catheter), conscious level, temperature, respiratory rate.
• Blood gas and lactate -metabolic acidosis, lactate (a marker of hypoperfusion and response to treatment), Hb, potassium, glucose.
• Bloods -FBC, U&E, LFTs, CRP, clotting (DIC), group and crossmatch, troponin, cultures, amylase or lipase, cortisol (if adrenal crisis suspected -but don't delay hydrocortisone).
• ECG -MI, arrhythmia, right heart strain (PE), low voltages (tamponade).
• Imaging -chest X-ray; point-of-care ultrasound (by trained staff) -heart function, pericardial effusion, RV dilatation, IVC size, free fluid, pneumothorax, AAA; CT for source (abdomen, PE).
• History -bleeding (melaena, haematemesis, PV bleeding), fluid losses, infection symptoms, chest pain, allergens, medications (anticoagulants, steroids, antihypertensives), trauma.
• Response to fluid -passive leg raise (fluid responsiveness), reassessment after boluses.

Fluid Resuscitation

• Crystalloids -500 mL bolus over under 15 minutes (NICE CG174), then reassess; balanced crystalloids (Hartmann's, Plasma-Lyte) or 0.9% sodium chloride; avoid starches (harm); albumin in specific situations.
• Sepsis -consider up to about 30 mL/kg in the first hours in septic shock (Surviving Sepsis), given as repeated boluses with reassessment; smaller boluses (250 mL) in heart failure, frailty or kidney failure.
• Haemorrhage -blood and blood products early rather than large volumes of crystalloid; major haemorrhage protocol (red cells, plasma, platelets in balanced ratios; fibrinogen; tranexamic acid where indicated).
• Signs of fluid overload -rising JVP, crackles, falling SpO₂, worsening breathlessness, peripheral oedema -stop fluids and consider vasopressors and critical care.
• After 2 litres without improvement (or earlier if lactate over 4 or MAP under 65) -critical care review for vasopressors.
• Don't over-resuscitate -positive fluid balance is linked with worse outcomes in sepsis and critical illness.
• Hypovolaemia from losses (vomiting, diarrhoea) -replace fluid and electrolytes (potassium, sodium) carefully.

Vasopressors and Inotropes

• Used in critical care (or HDU) with arterial line monitoring, usually via a central line (noradrenaline can be started peripherally short-term in some settings).
• Vasopressors (increase vascular tone):
  • Noradrenaline -first-line in septic shock (alpha-1 vasoconstriction, some beta-1); titrated to MAP 65 mmHg.
  • Vasopressin -second-line added to noradrenaline in septic shock.
  • Metaraminol and phenylephrine -short-term bolus or peripheral infusion (anaesthesia, peri-intubation).
• Inotropes (increase contractility):
  • Dobutamine -cardiogenic shock (beta-1); can cause hypotension (vasodilation) and arrhythmias.
  • Adrenaline -inotrope and vasopressor (anaphylaxis, refractory shock, cardiac arrest).
  • Milrinone (phosphodiesterase inhibitor), levosimendan (calcium sensitiser) -specialist.
• Steroids -hydrocortisone 200 mg/day in septic shock needing ongoing vasopressors (reduces time on vasopressors); essential in adrenal crisis.
• Mechanical support -intra-aortic balloon pump, Impella, ECMO (specialist centres).

Defining Sepsis

• Sepsis (Sepsis-3, 2016) -life-threatening organ dysfunction caused by a dysregulated host response to infection.
• Organ dysfunction -an acute change in SOFA (Sequential Organ Failure Assessment) score of 2 points or more (respiratory, coagulation, liver, cardiovascular, CNS, kidney).
• Septic shock -sepsis with circulatory and metabolic abnormalities severe enough to increase mortality: needs vasopressors to keep MAP at 65 mmHg or more and has a lactate over 2 mmol/L despite adequate fluid resuscitation (mortality over 40%).
• qSOFA (bedside prompt -one point each) -respiratory rate 22 or more, altered mentation, systolic BP 100 mmHg or less; 2 or more suggests higher risk (but not a screening tool for sepsis -NEWS2 is preferred in the UK).
• Older terms -"SIRS" criteria and "severe sepsis" are no longer used in Sepsis-3.
• Common sources -chest (most common), urinary tract, abdomen (perforation, cholangitis, abscess), skin and soft tissue, lines and devices, meningitis, endocarditis, bone and joints.

Recognising Sepsis

• Think "could this be sepsis?" in anyone with suspected infection who is unwell, or with unexplained deterioration -especially if NEWS2 is raised.
• NICE NG51 (2024 update) -uses NEWS2 to stratify risk in adults (16 and over, not pregnant) in acute hospitals:

  NEWS2	Risk of severe illness or death from sepsis	Action
  7 or more	High	Senior review; antibiotics within 1 hour; IV fluids; critical care review
  5–6	Moderate	Senior review within 1 hour; antibiotics within 3 hours (sooner if a clear infection source or worsening -within 1 hour if, e.g., AKI, high lactate, or neutropenia)
  1–4	Low (but higher if, e.g., new confusion, recent chemotherapy)	Clinical assessment; antibiotics within 3 hours if bacterial infection confirmed or likely

• Higher-risk groups -older and frail people, immunosuppressed (chemotherapy, steroids, biologics, transplant), recent surgery or invasive procedures, pregnancy or recent birth, IV drug use, indwelling lines, asplenia, diabetes, very young children.
• Red flags in any setting -new confusion, systolic BP 90 or less, HR over 130, RR 25 or more, needing oxygen to keep SpO₂ 92% or more, non-blanching rash, mottled or ashen skin, no urine for 18 hours, lactate 2 or more, recent chemotherapy.
• Atypical features -no fever (or hypothermia), normal WCC, presenting only with confusion or falls in older people.

The First Hour -Sepsis Six

• Sepsis Six (UK Sepsis Trust) -complete within 1 hour for high-risk patients:

  Step	Give three	Step	Take three
  1	Oxygen to target saturations (94–98% or 88–92%)	4	Blood cultures (and other cultures -urine, sputum -before antibiotics if no delay)
  2	IV antibiotics -broad-spectrum per local guidance, within 1 hour	5	Lactate (and full bloods -FBC, U&E, LFTs, CRP, clotting, glucose)
  3	IV fluids -500 mL bolus, repeat with reassessment if hypotensive or lactate raised	6	Urine output -hourly measurement (catheter if needed)

• Plus:
  • Senior review and escalation -critical care if lactate over 4, systolic BP under 90 despite fluids, or needing high oxygen or with reduced consciousness.
  • Find the source -history, examination, imaging.
  • Set a ceiling of care and communicate with the patient and family.
  • Review medicines -withhold antihypertensives, nephrotoxic drugs (NSAIDs, ACE inhibitors), metformin, SGLT2 inhibitors; steroid sick day rules.
  • Repeat lactate within 2–4 hours to assess response.

Source Identification, Antibiotics and Source Control

• Find the source -chest X-ray, urine (symptoms, culture -not dipsticks in over-65s), wound and line sites, abdominal examination (consider CT), skin (cellulitis, necrotising infection), joints, heart murmurs (endocarditis), neck stiffness (LP if meningitis suspected and safe), recent procedures.
• Empirical antibiotics -follow local microbiology guidelines; choose by suspected source, local resistance, allergies, recent antibiotics, MRSA or ESBL colonisation, and severity. Examples (vary locally):
  • Unknown source, high risk -e.g. piperacillin–tazobactam ± gentamicin (or a carbapenem if ESBL risk); add vancomycin or teicoplanin if MRSA risk.
  • Community-acquired pneumonia (severe) -co-amoxiclav plus clarithromycin.
  • Urosepsis -e.g. co-amoxiclav plus gentamicin, or as local policy.
  • Intra-abdominal -piperacillin–tazobactam (or co-amoxiclav + gentamicin + metronidazole regimens).
  • Meningitis -ceftriaxone 2 g IV (± amoxicillin if Listeria risk, ± dexamethasone).
  • Neutropenic sepsis -piperacillin–tazobactam within 1 hour.
• Source control -essential and time-critical:
  • Drain abscesses, empyema and infected collections.
  • Decompress an obstructed infected urinary tract (nephrostomy or stent).
  • ERCP for cholangitis; surgery for perforation, ischaemic bowel, necrotising fasciitis.
  • Remove infected lines and devices.
• Review at 48–72 hours -de-escalate based on cultures, switch to oral, set duration (Start Smart Then Focus -see the Clinical Pharmacology chapter).

Septic Shock

• Hypotension persisting despite adequate fluid, or lactate over 4 -critical care.
• Management (Surviving Sepsis Campaign):
  • Fluids -balanced crystalloids with frequent reassessment; avoid fluid overload.
  • Noradrenaline to a MAP of 65 mmHg; add vasopressin if needed; adrenaline or dobutamine if cardiac dysfunction.
  • Hydrocortisone 200 mg/day if needing ongoing vasopressors.
  • Antibiotics within 1 hour; source control.
  • Organ support -ventilation (lung-protective -ARDS), renal replacement therapy, blood glucose control (target about 8–10 mmol/L), VTE prophylaxis, stress ulcer prophylaxis where risk, nutrition.
  • Blood transfusion threshold -Hb 70 g/L in most.
• Lactate clearance and capillary refill time guide resuscitation.
• Sepsis survivors -often have weakness, fatigue, cognitive problems, anxiety and higher risk of readmission and death in the following year; "post-sepsis syndrome" -follow-up and rehabilitation.

Sepsis in Special Groups

• Neutropenic sepsis (neutrophils 0.5 × 10⁹/L or less, with fever over 38°C or signs of sepsis) -after chemotherapy (or carbimazole, clozapine, methotrexate) -empirical antibiotics (piperacillin–tazobactam) within 1 hour of presentation, without waiting for the FBC; acute oncology input (see the Oncology Emergencies chapter).
• Asplenia (splenectomy, sickle cell disease) -overwhelming post-splenectomy infection (pneumococcus, meningococcus, Hib) -rapid deterioration -immediate antibiotics.
• Pregnancy and post-partum -sepsis is a leading cause of maternal death; signs are masked by physiological changes; use the maternity early warning score; sources include genital tract (group A streptococcus), urinary, chest; involve obstetrics and consider fetal monitoring.
• Older people -atypical presentation (confusion, falls, low temperature); higher mortality; careful fluids; set ceilings of care.
• Immunosuppressed (steroids, biologics, transplant, HIV) -blunted signs, unusual organisms (PJP, fungi, CMV, Listeria); steroid users need extra hydrocortisone.
• People who inject drugs -endocarditis, abscesses, necrotising soft tissue infection, injection site infections (MRSA, group A strep, botulism, anthrax).
• Returning travellers -malaria (blood films), typhoid, viral haemorrhagic fever risk assessment.
• Hospital-acquired sepsis -lines, catheters, surgical sites, C. difficile, resistant organisms.

Sepsis with Rash -Meningococcal and Toxic Shock

• Meningococcal sepsis (Neisseria meningitidis):
  • Fever, non-blanching petechial or purpuric rash (glass test), limb pain, cold hands and feet, mottled skin, rapid deterioration; meningism may be absent.
  • Immediate IV or IM ceftriaxone (benzylpenicillin in primary care) -don't delay for tests; blood cultures and meningococcal PCR; critical care; DIC and purpura fulminans.
  • Notify UKHSA (public health); prophylaxis for close contacts (ciprofloxacin single dose).
• Toxic shock syndrome -toxins from Staphylococcus aureus (tampons, wounds, burns, nasal packing) or group A streptococcus:
  • High fever, diffuse red (sunburn-like) rash with later desquamation of palms and soles, hypotension, vomiting and diarrhoea, multi-organ failure.
  • Remove the source (tampon, packing), debride; IV antibiotics including clindamycin (stops toxin production); IVIG in severe cases; critical care.
• Necrotising fasciitis -pain out of proportion, rapid spread, shock -urgent surgery (see the Plastic Surgery page).
• Other causes of fever and rash -viral illnesses, drug reactions (DRESS, SJS), endocarditis (splinter haemorrhages, Janeway lesions), rickettsial infection, dengue, leptospirosis, vasculitis.

Cardiogenic and Obstructive Shock

• Cardiogenic shock -pump failure with hypoperfusion despite adequate filling:
  • Causes -large MI (commonest), mechanical complications (papillary muscle rupture -acute mitral regurgitation; ventricular septal rupture; free wall rupture), arrhythmias, myocarditis, Takotsubo, end-stage cardiomyopathy, valve disease, drug toxicity (beta-blockers, calcium channel blockers).
  • Features -cold, clammy, hypotensive, raised JVP, pulmonary oedema, low urine output, confusion, new murmur.
  • Management -oxygen, ECG and echo; urgent revascularisation (PCI) for MI; cautious fluids only if not congested; inotropes (dobutamine) and vasopressors (noradrenaline) in critical care; treat arrhythmias; CPAP or ventilation for pulmonary oedema; mechanical support; avoid beta-blockers and negative inotropes.
• Obstructive shock:
  • Massive PE -hypotension, hypoxia, raised JVP, RV dilatation on echo -thrombolysis (alteplase) if no contraindications; catheter or surgical embolectomy if contraindicated.
  • Tension pneumothorax -immediate decompression.
  • Cardiac tamponade -Beck's triad (hypotension, raised JVP, muffled heart sounds), pulsus paradoxus, low-voltage ECG, electrical alternans -pericardiocentesis (echo-guided).

Haemorrhagic Shock in Medical Patients

• Common medical causes -upper GI bleeding (peptic ulcer, varices), lower GI bleeding, ruptured AAA (back pain), retroperitoneal bleeding (on anticoagulants, after femoral procedures), ectopic pregnancy (women of childbearing age -pregnancy test), haemoptysis, bleeding on anticoagulants.
• Management:
  • ABCDE; two large-bore cannulas; crossmatch; FBC, clotting, fibrinogen, U&E (urea rises in upper GI bleeding), LFTs.
  • Activate the major haemorrhage protocol if bleeding is life-threatening; balanced blood products; avoid excessive crystalloid.
  • Reverse anticoagulants -PCC and vitamin K (warfarin); idarucizumab (dabigatran); andexanet alfa or PCC (factor Xa inhibitors).
  • Specific treatment -endoscopy (GI bleeding -within 24 hours, sooner if unstable), terlipressin and antibiotics for suspected variceal bleeding, interventional radiology (embolisation), surgery (AAA, ectopic).
  • Transfusion threshold -restrictive (Hb 70 g/L; 80 g/L with cardiovascular disease) once bleeding is controlled.
• Risk scoring -Glasgow–Blatchford score (pre-endoscopy -0 can be managed as outpatient), Rockall (post-endoscopy) (see the Gastroenterology Emergencies chapter).

Anaphylactic Shock

• Recognition -sudden airway and/or breathing and/or circulation problems, usually with skin or mucosal changes, after exposure to a trigger (drugs, foods, stings, contrast, latex).
• Treatment (RCUK 2021):
  • Remove the trigger; call for help; lie flat (sit up if breathing difficulty).
  • IM adrenaline 500 micrograms (0.5 mL of 1 mg/mL) in adults -repeat after 5 minutes if no improvement.
  • High-flow oxygen; IV fluid bolus (500–1,000 mL crystalloid).
  • Refractory (no improvement after 2 doses) -adrenaline infusion (experienced staff), more fluids, critical care; glucagon if on beta-blockers.
  • Not first-line -antihistamines (for skin symptoms once stable), steroids (no longer routinely recommended).
• After -mast cell tryptase (early and at 24 hours), observe (biphasic reactions), adrenaline auto-injectors, allergy referral, documentation (see the Clinical Pharmacology chapter).

Multi-organ Dysfunction, ARDS and DIC

• Multi-organ dysfunction syndrome (MODS) -progressive failure of two or more organs after severe illness (sepsis, trauma, pancreatitis, burns); mortality rises with each failing organ.
• Acute respiratory distress syndrome (ARDS):
  • Acute (within 1 week) hypoxaemic respiratory failure with bilateral infiltrates not fully explained by heart failure or fluid overload (Berlin definition -PaO₂/FiO₂ ratio grades severity).
  • Causes -direct (pneumonia, aspiration, inhalation, drowning, lung contusion) or indirect (sepsis, pancreatitis, trauma, massive transfusion -TRALI, burns).
  • Treatment -treat the cause; lung-protective ventilation (low tidal volume about 6 mL/kg ideal body weight, plateau pressure under 30 cmH₂O, PEEP); conservative fluids; prone positioning in severe ARDS; neuromuscular blockade; ECMO in selected cases.
• Disseminated intravascular coagulation (DIC):
  • Widespread activation of clotting -consumption of platelets and clotting factors -bleeding and thrombosis together.
  • Causes -sepsis (especially meningococcal), trauma, malignancy (acute promyelocytic leukaemia), obstetric emergencies (abruption, amniotic fluid embolism), severe liver failure.
  • Bloods -low platelets, prolonged PT and APTT, low fibrinogen, raised D-dimer, fragmented red cells.
  • Treatment -treat the cause; blood products if bleeding (platelets, FFP, cryoprecipitate for low fibrinogen); thromboprophylaxis where thrombosis predominates (see the Haematology chapters).
• AKI -common in sepsis -fluids, avoid nephrotoxins, renal replacement therapy if needed (see page 6).
• Critical illness polyneuromyopathy -weakness after prolonged ICU stay; rehabilitation.

Shock and Sepsis at a Glance

Condition	Key features	Key treatment
Hypovolaemic shock	Cold, flat neck veins, bleeding or losses	Stop bleeding, blood, fluids
Septic shock	Infection, MAP under 65 needing vasopressors, lactate over 2	Antibiotics within 1 hour, fluids, noradrenaline, source control
Anaphylactic shock	Trigger, airway or breathing problems, rash	IM adrenaline 500 micrograms, fluids
Neurogenic shock	Cord injury, low BP with bradycardia, warm	Fluids, vasopressors, atropine
Cardiogenic shock	Cold, raised JVP, pulmonary oedema, MI	PCI, inotropes, careful fluids
Massive PE	Hypoxia, raised JVP, RV dilatation	Thrombolysis
Tamponade	Beck's triad, pulsus paradoxus	Pericardiocentesis
Adrenal crisis	Steroid user, low Na, high K, vomiting	Hydrocortisone 100 mg IV
Neutropenic sepsis	Chemotherapy, fever	Piperacillin–tazobactam within 1 hour
Meningococcal sepsis	Non-blanching rash, rapid deterioration	Immediate ceftriaxone; notify; contacts prophylaxis
Toxic shock	Sunburn-like rash, shock, tampon or wound	Remove source, antibiotics with clindamycin
DIC	Low platelets, long PT and APTT, low fibrinogen	Treat cause, blood products

Spot the Diagnosis

Clue	Diagnosis
Warm peripheries, bounding pulse, low diastolic BP and fever	Early septic (distributive) shock
MAP 58 on noradrenaline with lactate 4.8 after 3 L of fluid	Septic shock
Melaena, HR 130, BP 85/50 and urea 25	Hypovolaemic shock -upper GI bleed
Back pain, collapse and pulsatile mass in a 74-year-old	Ruptured AAA
Collapse, raised JVP, clear lungs and RV dilatation after a long-haul flight	Massive PE -obstructive shock
Low BP, raised JVP, muffled heart sounds and electrical alternans	Cardiac tamponade
Cold, clammy, pulmonary oedema and new pansystolic murmur after MI	Papillary muscle rupture -cardiogenic shock
Hypotension, vomiting, sodium 124 and potassium 6.0 in a patient on long-term prednisolone	Adrenal crisis
Fever 7 days after chemotherapy, BP 95/60	Neutropenic sepsis
Purpuric rash, cold peripheries and fever in a student	Meningococcal sepsis
Sunburn-like rash and shock in a woman using tampons	Staphylococcal toxic shock syndrome
Sepsis with fever, rigors and jaundice	Ascending cholangitis -ERCP
Urosepsis with hydronephrosis behind a stone	Obstructed infected kidney -urgent decompression
Bilateral infiltrates and severe hypoxia 2 days after pancreatitis	ARDS
Bleeding from cannula sites, platelets 30, low fibrinogen in sepsis	DIC
Rapid collapse with pneumococcal sepsis after splenectomy	Overwhelming post-splenectomy infection

Exam-style Scenarios

1. An 80-year-old woman is admitted from a care home with confusion and reduced urine output. Temperature 35.6°C, HR 112, BP 84/50, RR 26, SpO₂ 92% on air. Lactate 4.6. Chest X-ray shows right lower lobe consolidation.
Answer: Sepsis with probable septic shock (pneumonia).

• Sepsis Six within 1 hour -oxygen to target, blood cultures, IV antibiotics (severe CAP per local guidance), 500 mL fluid boluses with reassessment, lactate, urine output (catheter).
• Withhold antihypertensives and nephrotoxic drugs; repeat lactate; check for delirium and other sources.
• Senior and critical care review (lactate over 4, hypotension); agree ceiling of care with the patient and family (frailty, wishes).

2. A 55-year-old man with type 2 diabetes has fever, rigors and right loin pain. BP 88/52 despite 1.5 L of fluid. Lactate 5. CT shows a 7 mm obstructing ureteric stone with hydronephrosis.
Answer: Septic shock from an obstructed infected kidney.

• Continue resuscitation; IV antibiotics (per local urosepsis guidance); critical care referral for noradrenaline.
• Urgent source control -percutaneous nephrostomy or ureteric stent within hours.
• Withhold metformin and SGLT2 inhibitor; monitor glucose and ketones; definitive stone treatment later.

3. A 63-year-old man has crushing chest pain, then becomes cold and confused. BP 76/48, HR 110, bilateral crackles, SpO₂ 88%. ECG shows anterior ST elevation.
Answer: Cardiogenic shock from anterior STEMI.

• Oxygen (CPAP if needed), aspirin and antiplatelet per cath lab protocol, emergency primary PCI.
• Avoid large fluid boluses (pulmonary oedema); inotropes (dobutamine) ± noradrenaline in CCU or ICU; echo for mechanical complications.
• Consider mechanical circulatory support in a specialist centre.

4. A 32-year-old woman had chemotherapy for breast cancer 9 days ago. She has a temperature of 38.5°C and feels shivery. Observations are otherwise normal.
Answer: Suspected neutropenic sepsis.

• IV piperacillin–tazobactam within 1 hour of arrival -don't wait for the FBC.
• Blood cultures (peripheral and from any central line), FBC, U&E, LFTs, CRP, lactate, urine, chest X-ray.
• Contact the acute oncology team; reassess risk (MASCC score) for possible early discharge on oral antibiotics if low risk.

5. A 19-year-old student has a headache, fever and leg pains for 6 hours. He now has a purple non-blanching rash on his legs, cold hands, HR 130 and BP 90/50.
Answer: Meningococcal sepsis.

• Immediate IV ceftriaxone 2 g (don't delay for LP or imaging); blood cultures and meningococcal PCR.
• Fluid resuscitation; early critical care (rapid deterioration, DIC); watch for raised intracranial pressure.
• Notify UKHSA; ciprofloxacin prophylaxis for close contacts (household, kissing contacts).

Key Points

• Shock -inadequate tissue perfusion; hypotension is a late sign; look at lactate, CRT, urine output and mental state.
• Four types -hypovolaemic, distributive (sepsis, anaphylaxis, neurogenic), cardiogenic, obstructive (PE, tension, tamponade).
• Fluid challenge -500 mL over under 15 minutes, then reassess; avoid overload.
• Noradrenaline is the first-line vasopressor in septic shock; target MAP 65 or more.
• Sepsis -life-threatening organ dysfunction from a dysregulated response to infection.
• Septic shock -vasopressors needed for MAP 65 and lactate over 2 despite fluids.
• Use NEWS2 to stratify sepsis risk -7 or more: antibiotics within 1 hour.
• Sepsis Six -oxygen, cultures, antibiotics, fluids, lactate, urine output -within 1 hour.
• Source control is as important as antibiotics -drain, decompress, remove lines, operate.
• Neutropenic sepsis -antibiotics within 1 hour without waiting for the count.
• Non-blanching rash with fever -immediate ceftriaxone.
• Steroid users in shock need hydrocortisone.
• Cardiogenic shock -revascularise, inotropes, avoid excess fluid.
• Massive PE -thrombolyse; tamponade -pericardiocentesis; tension -decompress.
• ARDS -lung-protective ventilation, prone positioning; DIC -treat the cause, replace products if bleeding.

Guidelines and Further Reading

• NICE NG51: Suspected sepsis -recognition, diagnosis and early management (updated 2024)
• UK Sepsis Trust: Sepsis Six and clinical tools
• Singer M et al.: The Third International Consensus Definitions for Sepsis and Septic Shock (Sepsis-3)
• Surviving Sepsis Campaign: International guidelines for management of sepsis and septic shock (2021)
• NICE CG174: Intravenous fluid therapy in adults in hospital
• NICE CG151: Neutropenic sepsis -prevention and management in people with cancer
• NICE NG240: Meningitis (bacterial) and meningococcal disease
• Resuscitation Council UK: Emergency treatment of anaphylaxis
• Faculty of Intensive Care Medicine and Intensive Care Society: ARDS guidelines
• BNF -for current doses