On-callIMT · ICU · acute

What's happening?

Tap the emergency. Every card starts with what to do in the first few minutes.

Pinned

Tap the ☆ on any card to pin it here for quick access.

Quick tools

Use with judgement. Typical adult doses from UK guidance (RCUK 2021, BTS, NICE, JBDS, UKKA and others), written for a doctor who already knows the basics. Check doses against the BNF, UHP protocols and Microguide, and escalate early. Do not enter patient identifiers anywhere on this site. Nothing you type leaves your phone.

Acute medicine

On-call emergencies by system. Red box = first minutes. Blue = then do. Green = targets.

Resuscitation and shock

Cardiac arrest (ALS)Arrest
Do now
  1. Call the arrest team (2222). Start CPR 30:2, 100 to 120/min, 5 to 6 cm. Pads on.
  2. Rhythm check every 2 minutes, pauses under 5 seconds. Charge during compressions.
  3. Shockable (VF/pVT): shock, CPR 2 min. Adrenaline 1 mg IV after 3rd shock, then every 3 to 5 min. Amiodarone 300 mg after 3rd shock, 150 mg after 5th.
  4. Non-shockable (PEA/asystole): adrenaline 1 mg IV as soon as access, then every 3 to 5 min.
  5. Airway: bag-mask then supraglottic or tube when skilled; waveform capnography; once secured, continuous compressions, 10 breaths/min.

Reversible causes

CauseCluesTreat
HypoxiaRespiratory arrest, tube problem100% O2, check airway (DOPES if intubated)
HypovolaemiaBleeding, sepsis, burnsFluids, blood, major haemorrhage protocol
Hypo/hyperkalaemia, metabolicRenal failure, DKA, RRTCalcium chloride 10% 10 ml, insulin-glucose, bicarbonate
HypothermiaCold exposure, drowningRewarm; withhold drugs below 30 C, double intervals 30 to 35 C
Thrombosis (PE)Risk factors, RV dilated on echoAlteplase 50 mg IV bolus; continue CPR 60 to 90 min
Thrombosis (coronary)Chest pain, STEMI before arrestCath lab discussion after ROSC
Tension pneumothoraxTrauma, ventilated, post lineNeedle or finger thoracostomy
TamponadeTrauma, post cardiac surgery or procedurePericardiocentesis / resternotomy
ToxinsHistory, pill bottlesAntidote (see table), lipid for LA toxicity, prolonged CPR

Monitored arrest (ICU, CCU, cath lab)

Witnessed VF/pVT with pads already on: up to 3 stacked shocks, then start CPR. Count the three as the first shock for drug timing.

After ROSC

Then
  • A to E, 12-lead ECG, ABG, chest X-ray.
  • SpO2 94 to 98%, normocapnia, MAP at least 65, glucose control.
  • STEMI or likely cardiac cause: cardiology for angiography.
  • CT head and/or CTPA if cause unclear. Avoid fever (below 37.7 C for 72 h).
  • ICU referral, document timings, debrief, speak to family.
Peri-arrest: adverse featuresEmergency

Any arrhythmia with one of these needs treating now, not in the morning:

Adverse features
  • Shock: hypotension (SBP below 90), pallor, sweating, cold peripheries, confusion.
  • Syncope: transient loss of consciousness.
  • Myocardial ischaemia: chest pain or ischaemic ECG changes.
  • Severe heart failure: pulmonary oedema, raised JVP.

Fast and adverse features: synchronised DC cardioversion, up to 3 shocks, then amiodarone 300 mg IV over 10 to 20 min and shock again. Details.

Slow and adverse features: atropine 500 mcg IV, repeat to 3 mg, then pacing. Details.

Not sure which? Use the arrhythmia decision tool.

Hypotension and shock: approachEmergency
Do now
  1. A to E, high-flow O2, two large cannulae, bloods incl. lactate, cultures, group and save, VBG.
  2. Lie flat, legs up (passive leg raise tells you if fluid will help).
  3. 500 ml crystalloid over 15 min, reassess. Repeat once if responding; if not, think why.
  4. ECG: arrhythmia, STEMI, PE pattern. Look at the JVP.
  5. Senior and outreach/ICU early if not responding after 2 boluses or lactate 4 or more.
TypePictureTreat
HypovolaemicCold, flat neck veins, bleeding/lossesVolume, blood if bleeding, stop the source
Distributive (sepsis, anaphylaxis)Warm early, boundingFluids, antibiotics, noradrenaline; adrenaline for anaphylaxis
CardiogenicCold, wet, raised JVP, cracklesNo big fluid boluses; cardiology, inotropes on ICU
ObstructiveRaised JVP, clear chestPE: lysis. Tamponade: drain. Tension: decompress

On the ward, metaraminol boluses (0.5 to 1 mg) can bridge while ICU is coming. See vasopressors.

Sepsis1 hour

Think sepsis in anyone with infection and NEWS2 5 or more, or any single red flag: new confusion, SBP 90 or less, HR above 130, RR 25 or more, needing O2 for SpO2 92% or more, non-blanching rash, no urine for 18 h, lactate 2 or more.

Within 1 hour (high risk)
  1. Senior review. O2 to target.
  2. Blood cultures (before antibiotics if no delay), lactate, FBC, U&E, CRP, LFT, clotting.
  3. IV antibiotics per Microguide for the likely source.
  4. Lactate above 2 or SBP below 90: 500 ml crystalloid over under 15 min, reassess, repeat.
  5. Catheter and hourly urine output if shocked.
Then
  • Find and control the source: CXR, urine, imaging for collections, remove infected lines.
  • Lactate 4 or more, or SBP below 90 despite fluid: critical care referral now.
  • Review antibiotics with cultures at 48 to 72 h.
Neutropenic sepsisChemo patient, temperature above 38 or unwell: piperacillin-tazobactam 4.5 g IV within 1 hour (or local equivalent). Do not wait for the FBC.
AnaphylaxisEmergency
Do now
  1. Remove trigger (stop the infusion). Call for help. Lie flat (sit up if breathing difficulty; left side if pregnant).
  2. Adrenaline 500 mcg IM (0.5 ml of 1 mg/ml) into anterolateral thigh. Repeat after 5 min if not improving.
  3. High-flow O2, IV access, 500 to 1000 ml crystalloid bolus.
  4. Monitor ECG, SpO2, BP.
Refractory (no better after 2 IM doses)
  • Senior/ICU now. Adrenaline infusion (expert). Further fluid.
  • In monitored ICU/theatre: IV adrenaline 50 mcg boluses titrated.
  • On beta-blockers: consider glucagon.
  • Antihistamines and steroids are not first-line; they do not treat airway or shock.

Mast cell tryptase as soon as possible after starting treatment and at 1 to 2 h. Observe (often 6 to 12 h), adrenaline auto-injector and allergy clinic referral on discharge.

Upper GI bleed and major haemorrhageEmergency
Do now
  1. A to E, two large cannulae, FBC, U&E (urea), LFT, clotting, crossmatch.
  2. Unstable or ongoing massive bleed: activate major haemorrhage protocol.
  3. Transfuse: Hb below 70 (below 80 if cardiovascular disease). Platelets if below 50 and bleeding. FFP if INR or APTT above 1.5x and bleeding.
  4. Suspected variceal (liver disease): terlipressin 2 mg IV 6-hourly plus IV antibiotics (Microguide).
  5. Reverse anticoagulation (see reversal).
Then
  • Glasgow-Blatchford score (0 can be outpatient). Calculate pre-endoscopy.
  • Endoscopy: immediately after resuscitation if unstable; within 24 h for everyone else.
  • PPI after endoscopy for non-variceal bleeding (not routinely before).
  • Uncontrolled variceal bleed: senior, ICU, balloon tamponade, TIPS.
  • Tranexamic acid is not recommended in GI bleeding (HALT-IT).

Major haemorrhage on any ward

  • Products in ratio, guided by results or viscoelastic testing.
  • Keep fibrinogen above 1.5 g/L, platelets above 75, ionised Ca above 1.0.
  • Trauma, obstetric or surgical bleeding: tranexamic acid 1 g IV.
  • Warm the patient and the fluids; avoid acidosis.

Cardiovascular

Chest pain and ACSEmergency
Do now
  1. ECG within 10 minutes; repeat if pain continues or changes. Add posterior (V7 to V9) leads if ST depression V1 to V3.
  2. STEMI (or new LBBB with ongoing ischaemia, posterior MI) within 12 h of onset: call the PPCI / cath lab team now.
  3. Aspirin 300 mg loading (unless allergic). Second antiplatelet per local protocol and cardiology.
  4. O2 only if SpO2 below 94%. GTN for pain if SBP above 90. IV opioid with antiemetic if needed.
NSTEMI / unstable angina
  • High-sensitivity troponin at 0 and 1 to 3 h per local pathway.
  • Aspirin 300 mg, then 75 mg OD. Fondaparinux 2.5 mg SC OD (if no high bleeding risk and not going for immediate angiography).
  • Second antiplatelet (often ticagrelor 180 mg load) per cardiology.
  • GRACE score; intermediate or high risk for angiography within 72 h.
  • Secondary prevention: statin, beta-blocker, ACE inhibitor, echo.
Don't missAortic dissection (tearing pain to back, pulse or BP difference between arms, widened mediastinum): no antiplatelets or anticoagulation; CT aorta. PE, tension pneumothorax, oesophageal rupture, pericarditis (saddle ST elevation, PR depression).
Acute pulmonary oedema / heart failureEmergency
Do now
  1. Sit up, O2 to SpO2 94 to 98% (88 to 92% if hypercapnic risk). ECG, troponin, BNP, CXR, ABG.
  2. Furosemide IV 40 to 80 mg (or at least their usual oral dose given IV if already on a loop).
  3. CPAP if hypoxic or in respiratory distress despite oxygen (outreach/ICU or respiratory).
  4. GTN infusion if SBP above 110 (titrate to BP, stop if SBP below 90).
  5. Treat the trigger: ACS, fast AF, hypertension, valve problem, fluid overload, infection.
Then
  • Fluid restriction, daily weights, strict fluid balance, U&E daily.
  • Poor response: double the furosemide, infusion, add thiazide (metolazone) with senior advice.
  • Cardiogenic shock (hypotension with poor perfusion): ICU and cardiology, echo now.
  • Do not stop beta-blockers routinely unless shocked or bradycardic.
Pulmonary embolismEmergency
High-risk PE (shock or SBP below 90)
  1. Senior and ICU now. O2, careful fluids (small boluses only: the RV is failing).
  2. Bedside echo if CT unsafe: RV dilatation supports PE.
  3. Unfractionated heparin bolus then infusion.
  4. Thrombolysis: alteplase 10 mg IV over 1 to 2 min, then 90 mg over 2 h (max 1.5 mg/kg if under 65 kg). In arrest: 50 mg bolus.
  5. Avoid intubation if possible (can precipitate arrest); noradrenaline for BP.
Stable suspected PE
  • Two-level Wells (calculator). Above 4: CTPA. 4 or less: D-dimer, CTPA if positive.
  • Start anticoagulation while waiting if a delay: apixaban 10 mg BD for 7 days then 5 mg BD, or rivaroxaban 15 mg BD for 21 days then 20 mg OD, or LMWH.
  • Renal failure (CrCl below 15) or very high bleeding risk: UFH or LMWH with advice.
  • Intermediate risk (RV strain on CT/echo plus raised troponin): monitor closely, rescue lysis if deteriorates.
  • sPESI 0 and stable: consider ambulatory pathway.
Hypertensive emergency and aortic dissection

Hypertensive emergency = severe BP with acute organ damage (encephalopathy, stroke, pulmonary oedema, ACS, AKI, retinal haemorrhage/papilloedema, eclampsia). Very high BP without organ damage is an urgency: oral treatment, do not drop it fast.

Treat
  • HDU/ICU, arterial line. IV labetalol (or GTN if pulmonary oedema/ACS) per local protocol.
  • Lower MAP by no more than 25% in the first hour, then towards 160/100 over the next 2 to 6 h.
  • Exceptions: aortic dissection (target SBP 100 to 120 and HR below 60 quickly), pre-eclampsia, stroke (see stroke card).
Aortic dissectionSudden tearing chest or back pain, pulse deficit, BP difference, new AR murmur, neuro signs. CT aortogram. IV labetalol or esmolol first (rate before pressure), opioid analgesia, cardiothoracic/vascular referral. Type A (ascending) is surgical.

Respiratory

Acute asthmaEmergency
SeverityFeatures (any one)
ModeratePEF 50 to 75% best/predicted, no severe features
Acute severePEF 33 to 50%, RR 25 or more, HR 110 or more, cannot complete sentences
Life-threateningPEF below 33%, SpO2 below 92%, PaO2 below 8 kPa, normal PaCO2 (4.6 to 6.0), silent chest, cyanosis, poor effort, exhaustion, confusion, arrhythmia, hypotension
Near-fatalRaised PaCO2 or needing ventilation
Do now
  1. O2 to SpO2 94 to 98%.
  2. Salbutamol 5 mg nebulised (O2-driven), back-to-back if severe.
  3. Ipratropium 500 mcg nebulised 4 to 6 hourly in acute severe or life-threatening.
  4. Prednisolone 40 to 50 mg PO (or hydrocortisone 100 mg IV 6-hourly if unable to swallow), continue at least 5 days.
  5. ABG if SpO2 below 92% or any life-threatening feature.
Not improving or life-threatening
  • Magnesium sulfate 1.2 to 2 g IV over 20 min (single dose).
  • ICU referral: life-threatening/near-fatal features, rising PaCO2, worsening despite treatment, exhaustion, drowsiness.
  • IV aminophylline only with senior advice (check theophylline use first).
  • CXR if pneumothorax, consolidation or ventilation considered.

A normal PaCO2 in an acute asthmatic is a bad sign: they are tiring.

COPD exacerbation and NIV
Do now
  1. Target SpO2 88 to 92% via Venturi (24 or 28%). ABG early and 30 to 60 min after any O2 change.
  2. Salbutamol 2.5 to 5 mg and ipratropium 500 mcg nebulised (air-driven; give O2 by nasal cannulae alongside).
  3. Prednisolone 30 mg OD for 5 days.
  4. Antibiotics if purulent sputum or pneumonia (Microguide). CXR, ECG.
NIV (BTS/ICS)
  • Indication: pH below 7.35 and PaCO2 above 6.5 kPa persisting after optimal medical treatment (about 1 hour).
  • Start IPAP 15, EPAP 3 to 5 (higher if obese/OSA). Increase IPAP to 20 to 30 over 10 to 30 min as tolerated.
  • ABG at 1 h (and 4 h). No improvement in pH/RR: senior review.
  • Document the ceiling of care before starting: what happens if NIV fails (intubation or palliation).
  • Contraindications/cautions: pneumothorax (drain first), vomiting, unable to protect airway, facial trauma, copious secretions.
Pneumothorax
TensionHypotension, hypoxia, deviated trachea (late): needle or finger thoracostomy (2nd ICS mid-clavicular or 4th/5th ICS mid-axillary), then chest drain.
Non-tension (BTS 2023 approach)
  • Primary (no lung disease), minimal symptoms: conservative management with follow-up is an option whatever the size.
  • Primary, symptomatic: needle aspiration or ambulatory device; drain if this fails.
  • Secondary (underlying lung disease, or over 50 and smoker): admit; usually a chest drain; respiratory review.
  • Oxygen if hypoxic. Never clamp a bubbling drain.
Pneumonia
  • CXR, cultures if moderate/severe, urinary pneumococcal and legionella antigens if severe.
  • CURB-65 (calculator) guides severity: 0 to 1 low, 2 moderate, 3 to 5 high (consider HDU/ICU).
  • Antibiotics within 4 hours (1 hour if septic) per Microguide, by severity.
  • Hospital-acquired (48 h after admission) and aspiration: different regimens, check Microguide.
  • Repeat CXR at 6 weeks only if symptoms persist or high cancer risk.

Neurology

Seizures and status epilepticusEmergency
0 to 5 minutes
  1. Time it. Protect from injury, recovery position, O2, suction. Check glucose (treat if below 4).
  2. IV access, bloods: U&E, Ca, Mg, glucose, antiepileptic levels, VBG, CK.
5 minutes: first-line
  • Lorazepam 4 mg IV (0.1 mg/kg, max 4 mg). Repeat once after 5 to 10 min.
  • No IV: buccal midazolam 10 mg, or rectal diazepam 10 to 20 mg.
  • Alcohol use or malnourished: Pabrinex IV.
After 2 benzodiazepine doses: second-line (pick one)
  • Levetiracetam 60 mg/kg IV (max 4.5 g) over 10 min.
  • Phenytoin 20 mg/kg IV (max 2 g) at up to 50 mg/min, ECG and BP monitoring.
  • Sodium valproate 40 mg/kg IV (max 3 g). Avoid in women and girls of childbearing potential and in liver disease.
Still seizing (refractory)ICU/anaesthetics now: RSI, propofol or thiopental, EEG. Look for cause: hypoglycaemia, Na, Ca, alcohol withdrawal, drugs, infection (meningitis/encephalitis), stroke, tumour, eclampsia (magnesium), non-adherence.

First seizure, now recovered: neuro exam, ECG (long QT, Brugada), bloods, CT if indicated, DVLA advice documented, first-fit clinic.

StrokeTime-critical
Do now
  1. Time last known well. Glucose (exclude hypoglycaemia). NIHSS/ROSIER.
  2. Stroke team bleep / pre-alert. CT head now (plus CT angiogram if thrombectomy candidate).
  3. Nil by mouth until swallow screen. Check anticoagulants and last dose.
Ischaemic
  • Thrombolysis within 4.5 h of onset if no contraindications (stroke team decides). BP must be below 185/110 before and below 180/105 for 24 h after.
  • Thrombectomy for large vessel occlusion: up to 6 h, and up to 24 h with imaging selection. Discuss with the regional centre.
  • Aspirin 300 mg once haemorrhage excluded (24 h after lysis, after a repeat scan), for 2 weeks, then long-term antiplatelet.
Intracerebral haemorrhage
  • Reverse anticoagulation immediately (PCC/vitamin K for warfarin, specific reversal for DOACs).
  • SBP 150 to 220: lower to 130 to 140 within 1 hour (do not drop SBP by more than 60 mmHg within 1 hour).
  • Neurosurgical referral if hydrocephalus, posterior fossa bleed or deterioration.

TIA: aspirin 300 mg and TIA clinic within 24 h (NICE). Do not use ABCD2 to triage.

Reduced GCSEmergency
Do now
  1. Airway: head tilt/jaw thrust, adjuncts, recovery position. GCS 8 or less, or falling, usually needs airway protection: anaesthetics/ICU.
  2. Glucose (don't ever forget glucose). ABG/VBG (CO2, Na, lactate). O2.
  3. Pupils, focal signs, neck stiffness, rash, injuries, pinpoint pupils.
  4. Drug chart and history: opioids (naloxone), benzodiazepines, sedatives, insulin, alcohol, overdose.
Causes to work through
  • Metabolic: glucose, Na, Ca, urea, ammonia (liver), CO2 (type 2 failure), thyroid, adrenal, hypothermia.
  • Neuro: stroke, ICH, SAH, seizure/post-ictal, non-convulsive status, raised ICP.
  • Infection: sepsis, meningitis, encephalitis.
  • Drugs/toxins: opioids, sedation, alcohol, overdose, Wernicke's.
  • Shock/hypoperfusion.

CT head if no obvious reversible cause, focal signs, head injury, or anticoagulated.

Raised ICP / herniationBlown pupil, Cushing's response (bradycardia, hypertension): head up 30 degrees, airway, PaCO2 4.5 to 5.0, mannitol (0.25 to 1 g/kg) or hypertonic saline per local protocol, urgent neurosurgery.
Meningitis and encephalitis1 hour
Do now
  1. Blood cultures, then ceftriaxone 2 g IV 12-hourly within 1 hour. Do not delay for CT or LP.
  2. Add amoxicillin 2 g IV 4-hourly if over 60 or immunocompromised (Listeria).
  3. Dexamethasone 10 mg IV 6-hourly with or just before first antibiotic dose if bacterial meningitis suspected (stop if not pneumococcal/bacterial).
  4. Encephalitis features (confusion, behaviour change, seizures, focal signs): add aciclovir 10 mg/kg IV 8-hourly (renal dose).
  5. Penicillin anaphylaxis or recent travel: check Microguide / micro.
LP
  • Within 1 hour if safe. CT first only if: focal neurology, GCS 12 or less, papilloedema, new seizures, severe immunocompromise.
  • Send: opening pressure, cell count, protein, glucose (with paired plasma), Gram stain, culture, PCR (meningococcus, pneumococcus, HSV, VZV, enterovirus).
  • Meningococcal disease: notify UKHSA, contact prophylaxis.
Metastatic spinal cord compression
  • Cancer plus back pain with neuro symptoms (weakness, sensory level, sphincter problems).
  • Dexamethasone 16 mg (PO or IV) with PPI cover, then daily, monitor glucose.
  • Whole spine MRI within 24 h (immediately if neurological deficit).
  • Lie flat with log-roll if pain suggests spinal instability.
  • Contact acute oncology / MSCC coordinator for surgery or radiotherapy.

Endocrine and metabolic

DKA and HHSEmergency

DKA: ketones 3.0 or more (or urine ++), glucose above 11 or known diabetes, pH below 7.3 and/or bicarbonate below 15. Euglycaemic DKA happens (SGLT2 inhibitors, pregnancy).

Do now
  1. A to E, VBG, ketones, glucose, U&E, FBC, cultures, ECG.
  2. Fluids: 0.9% saline. SBP below 90: 500 ml over 10 to 15 min, repeat. Then roughly 1 L over 1 h, 1 L over 2 h, 1 L over 2 h, 1 L over 4 h, 1 L over 4 h, 1 L over 6 h (slower if elderly, heart failure, young adult 18 to 25).
  3. Fixed-rate IV insulin 0.1 units/kg/h (actual weight). Continue long-acting basal insulin.
  4. Potassium (per litre of fluid): K above 5.5 none; 3.5 to 5.5 give 40 mmol/L; below 3.5 senior review, more K needed, may need to delay insulin (ICU).
  5. Add 10% glucose at 125 ml/h when glucose falls below 14.
TargetsKetones falling at least 0.5 mmol/L/h. Bicarbonate rising at least 3 mmol/L/h. Glucose falling about 3 mmol/L/h. K 4.0 to 5.5. VBG at 60 min, 2 h, then 2-hourly. If targets missed: check pump/line, then increase insulin by 1 unit/h.
Then
  • Resolution: ketones below 0.6 and pH above 7.3. Switch to subcutaneous insulin with a meal, stop FRIII 30 to 60 min after the SC dose.
  • Find the trigger (infection, missed insulin, MI). Diabetes team review. VTE prophylaxis.
  • HDU/ICU (JBDS): ketones above 6, bicarbonate below 5, pH below 7.0, K below 3.5 on admission, GCS below 12, SpO2 below 92% on air, SBP below 90, HR above 100 or below 60, anion gap above 16. Also pregnancy, heart or renal failure.

HHS

  • Osmolality 320 or more (2Na + glucose + urea), glucose 30 or more, no significant ketonaemia (below 3), pH above 7.3. Often elderly, very dry.
  • 0.9% saline 1 L over 1 h, then titrate. Aim glucose fall 4 to 6 mmol/L/h and sodium fall no more than 10 mmol/L in 24 h.
  • Insulin only once glucose stops falling with fluids alone, or if ketones above 1: FRIII 0.05 units/kg/h.
  • High VTE risk: prophylactic LMWH. Check feet.
HypoglycaemiaEmergency
Glucose below 4 mmol/L
  • Conscious and can swallow: 15 to 20 g fast-acting carbohydrate (e.g. 150 to 200 ml pure fruit juice, or 4 to 5 glucose tablets). Recheck in 10 to 15 min; repeat up to 3 times.
  • Drowsy, fitting, nil by mouth, or not improving: IV glucose: 75 ml of 20% over 10 to 15 min (or 150 ml of 10%). Recheck at 10 min.
  • No IV access: glucagon 1 mg IM (works poorly in liver disease, starvation, alcohol, sulfonylurea overdose).

Once above 4: a long-acting carbohydrate snack or meal. Do not omit the next insulin dose, but review the regimen and the cause. Sulfonylurea hypos recur: monitor for 24 h, consider 10% glucose infusion; octreotide in overdose (TOXBASE).

Hyponatraemia
Severe symptoms (seizures, reduced GCS, vomiting, cardiorespiratory distress)
  • 150 ml hypertonic saline (2.7% or 3%, as stocked) IV over 20 min. Check Na. Repeat up to twice until Na rises by 5 mmol/L or symptoms improve. HDU/ICU and senior involvement.
Correction limitNo more than 10 mmol/L in the first 24 h and 8 per 24 h after (aim 8 or less in high risk: alcohol, malnutrition, hypokalaemia, liver disease, Na below 120). Check Na every 2 to 4 h. Overcorrecting: stop the cause, 5% glucose, discuss desmopressin with senior/endocrine.
Work-up
  • Paired serum and urine osmolality, urine Na, TFT, 9 am cortisol (or random if unwell), glucose, lipids/protein if pseudohyponatraemia suspected.
  • Volume status: dry (diuretics, GI losses, Addison's), wet (heart/liver/kidney failure), normal (SIADH, hypothyroid, adrenal insufficiency, drugs).
  • Drugs: thiazides, SSRIs, carbamazepine, PPIs, opioids, antipsychotics.
  • SIADH: fluid restriction (e.g. 1 L/day) first; tolvaptan or urea only with specialist advice.
Hypercalcaemia
  • Corrected Ca above 3.0 significant, above 3.5 severe (calculator). Symptoms: confusion, thirst, polyuria, constipation, abdominal pain, short QT.
  • IV 0.9% saline 3 to 4 L over 24 h if heart allows; monitor fluid balance.
  • Then zoledronic acid 4 mg IV over 15 min (dose-adjust in renal impairment) or pamidronate. Effect takes 2 to 4 days.
  • Stop thiazides, calcium, vitamin D. Send PTH (before treatment), PTHrP, myeloma screen, vitamin D.
  • Hypocalcaemia (symptomatic or below 1.9): 10 ml 10% calcium gluconate IV over 10 min with ECG monitoring, then infusion; check Mg.
Adrenal crisisEmergency
Do now
  • Hydrocortisone 100 mg IV/IM immediately, then 50 mg 6-hourly IV/IM (or 200 mg/24 h infusion).
  • 1 L 0.9% saline over 1 h, then more by response. Check and treat glucose.
  • Find the trigger (infection, missed steroids, vomiting). Endocrine review.

Anyone on long-term steroids (5 mg prednisolone or more for over 4 weeks) who is acutely unwell, fasting or having surgery needs stress-dose cover. Do not stop steroids abruptly.

Thyroid storm and myxoedema coma

Thyroid storm (fever, tachycardia/AF, agitation, heart failure, GI upset): ICU/endocrine; propranolol, carbimazole or propylthiouracil, then Lugol's iodine (at least 1 h after thionamide), hydrocortisone, cooling, treat trigger.

Myxoedema coma (hypothermia, bradycardia, reduced GCS, hyponatraemia, hypoglycaemia): ICU/endocrine; hydrocortisone before levothyroxine/liothyronine, passive rewarming, supportive care.

Renal and electrolytes

HyperkalaemiaEmergency

Mild 5.5 to 5.9. Moderate 6.0 to 6.4. Severe 6.5 or more, or any ECG change (peaked T, flat P, broad QRS, bradycardia, sine wave). Rule out haemolysis but don't wait for a repeat if the ECG is abnormal.

K 6.5 or more, or ECG changes (UKKA 2023)
  1. Cardiac monitor. Protect the heart: calcium chloride 10% 10 ml IV (large vein/central), or calcium gluconate 10% 30 ml IV over 5 to 10 min. Repeat ECG; give more if changes persist.
  2. Shift K in: soluble insulin (Actrapid) 10 units with 25 g glucose IV over 15 min (e.g. 250 ml 10% glucose, or 50 ml 50%). If pre-treatment glucose below 7, follow with 10% glucose 50 ml/h for 5 h.
  3. Salbutamol 10 to 20 mg nebulised as an add-on (caution: tachyarrhythmia, IHD).
  4. Remove K: sodium zirconium cyclosilicate 10 g TDS (oral). Stop K supplements, ACEi/ARB, spironolactone, trimethoprim, NSAIDs. Treat AKI cause.
  5. Glucose hourly for 6 h (hypoglycaemia is common, especially CKD). K at 1, 2, 4, 6, 24 h.
EscalateRefractory hyperkalaemia, anuria, severe AKI or acidosis: renal/ICU for dialysis. Digoxin toxicity changes the calcium decision: get senior advice.
Acute kidney injury
KDIGO stageCreatinineUrine output
11.5 to 1.9x baseline, or rise of 26 µmol/L in 48 hBelow 0.5 ml/kg/h for 6 to 12 h
22.0 to 2.9xBelow 0.5 ml/kg/h for 12 h or more
33x, or 354 µmol/L or more, or RRTBelow 0.3 ml/kg/h for 24 h, or anuria 12 h
Every AKI
  • Volume status and BP: fluid if dry, stop if overloaded.
  • Stop/hold nephrotoxins and risky drugs (DAMN: diuretics, ACEi/ARB, metformin, NSAIDs; also gentamicin, contrast, lithium). Renally dose everything.
  • Urine dip (blood/protein: think glomerulonephritis, send ACR/PCR, refer). Bladder scan; catheter if retention.
  • Renal USS within 24 h if obstruction possible or no clear cause.
  • K, bicarbonate, fluid balance chart, daily U&E. CK if rhabdo possible.
Urgent RRT indications (refractory)K above 6.5, pH below 7.15 to 7.2, pulmonary oedema not responding to diuretics, uraemic pericarditis or encephalopathy, dialysable toxins (lithium, methanol, ethylene glycol, salicylate, metformin).
K, Mg, PO4 replacement
ProblemReplacement (typical)
K 3.0 to 3.4Oral: Sando-K 2 tablets BD to TDS (12 mmol K per tablet), recheck
K below 3.0 or symptomaticIV: 40 mmol KCl in 1 L 0.9% saline over at least 4 h peripherally (max 10 mmol/h peripheral; faster only via central line on HDU/ICU with monitoring)
Mg below 0.5, or arrhythmiaMagnesium sulfate 20 mmol IV over 4 to 12 h; in arrhythmia 2 g (8 mmol) over 10 to 15 min
PO4 below 0.32 (severe)IV phosphate per local protocol over 12 to 24 h (reduce in renal impairment)

Low K that won't correct: replace Mg. Arrhythmia patients: aim K 4.0 to 5.0, Mg above 1.0.

Never give concentrated KCl as a bolus. Use premixed bags.

GI and liver

Decompensated liver disease
  • Look for the trigger: GI bleed, infection (SBP: diagnostic ascitic tap in every admission, neutrophils above 250/mm³), alcohol, constipation, drugs, AKI, hepatocellular carcinoma, portal vein thrombosis.
  • Encephalopathy: lactulose 20 to 30 ml 2 to 4 times daily, aim 2 to 3 soft stools/day; add rifaximin. Phosphate enemas if not opening bowels.
  • SBP: antibiotics per Microguide plus albumin 1.5 g/kg on day 1 and 1 g/kg day 3.
  • Large-volume paracentesis: 20% albumin, 100 ml per 2 to 3 L drained (about 8 g per litre).
  • AKI/hepatorenal: stop diuretics and nephrotoxins, albumin, terlipressin with hepatology.
  • Alcohol: Pabrinex, withdrawal regimen (card). Glucose checks. Vitamin K if INR raised (limited effect).
Alcohol withdrawal and Wernicke's
  • Withdrawal starts 6 to 24 h after last drink; seizures peak 12 to 48 h; delirium tremens 48 to 72 h.
  • Use CIWA-Ar to guide: chlordiazepoxide reducing regimen or symptom-triggered per local protocol. Lower dose/lorazepam in liver failure or elderly.
  • Pabrinex: prophylaxis 1 pair IV OD for 3 to 5 days; suspected Wernicke's (confusion, ataxia, ophthalmoplegia, or any unexplained confusion in a drinker) 2 pairs IV TDS for 3 to 5 days. Give before glucose where practical.
  • Delirium tremens: medical emergency, high dependency, IV benzodiazepines, fluids, electrolytes (K, Mg, PO4), look for infection and head injury.

Toxicology

Overdose: paracetamol and opioidsEmergency

Always check TOXBASE (or call NPIS 0344 892 0111). Glucose, ECG (QRS, QTc), VBG, paracetamol and salicylate levels for any overdose.

Paracetamol
  • Single acute ingestion within 8 h: level at 4 h or later; treat if above the line (100 mg/L at 4 h).
  • Start acetylcysteine immediately without waiting for a level if: more than 8 h since ingestion and 150 mg/kg or more, staggered overdose, timing unknown, or jaundiced/abnormal LFTs.
  • Regimen per local protocol (many UK trusts use the 12-hour SNAP regimen). Dose by weight (cap at 110 kg).
  • Repeat INR, ALT, creatinine, VBG at end of infusion; continue if abnormal. Liver unit criteria (e.g. pH below 7.3, INR above 3 at 48 h, rising creatinine, encephalopathy): discuss early.
Opioids
  • Reduced GCS, RR below 10, pinpoint pupils: support breathing with bag-mask first.
  • Naloxone 400 mcg IV, repeat every 2 to 3 min (up to 2 mg, more for some). Opioid-dependent or palliative: smaller titrated doses (100 to 200 mcg) to avoid acute withdrawal and pain crisis.
  • Naloxone wears off in about 1 h; long-acting opioids (methadone, MR preparations) may need an infusion. Observe.

Mental capacity and safeguarding: document, psych liaison once medically fit.

Antidotes table
PoisonAntidote / key treatment
ParacetamolAcetylcysteine
OpioidsNaloxone
BenzodiazepinesFlumazenil: rarely, specialist only (risk of seizures in mixed overdose or dependence)
Beta-blockersGlucagon, high-dose insulin euglycaemia, pacing
Calcium channel blockersCalcium, high-dose insulin euglycaemia
DigoxinDigoxin-specific antibody fragments (DigiFab)
Tricyclics (broad QRS, arrhythmia)Sodium bicarbonate 8.4% 50 to 100 ml
Local anaesthetic toxicityLipid emulsion 20%: 1.5 ml/kg bolus then infusion (AAGBI)
HeparinProtamine
WarfarinVitamin K, prothrombin complex concentrate
DabigatranIdarucizumab 5 g IV
Methanol, ethylene glycolFomepizole (or ethanol), haemodialysis
IronDesferrioxamine
Cyanide (smoke inhalation)Hydroxocobalamin
OrganophosphatesAtropine (large doses), pralidoxime
SulfonylureasGlucose, octreotide
SalicylatesSodium bicarbonate (urinary alkalinisation), haemodialysis
Carbon monoxide100% O2 (hyperbaric rarely)

Haematology

Anticoagulant reversal and high INR
Warfarin, major bleedingStop warfarin. Vitamin K 5 to 10 mg IV plus prothrombin complex concentrate (e.g. 25 to 50 units/kg, per haematology/local). Recheck INR.
Situation (warfarin)Action
INR above 8, no bleedingStop warfarin, vitamin K 1 to 5 mg orally, restart when INR below 5
INR 5 to 8, no bleedingWithhold 1 to 2 doses, reduce maintenance
INR 5 to 8, minor bleedingStop, vitamin K 1 to 3 mg IV
DOACs, major bleeding
  • Note time of last dose and renal function.
  • Dabigatran: idarucizumab 5 g IV.
  • Apixaban/rivaroxaban: andexanet alfa where approved locally, otherwise PCC. Haematology advice.
  • Tranexamic acid often used as an adjunct (not in GI bleeding).

Heparin: protamine (1 mg per 100 units given in the last 2 h for UFH; partial reversal only for LMWH).

Fluid prescribing
  • Resuscitation: 500 ml crystalloid over under 15 min, reassess. (250 ml in heart failure/frail.)
  • Maintenance (NICE CG174): 25 to 30 ml/kg/day water, about 1 mmol/kg/day each of Na, K and Cl, 50 to 100 g/day glucose.
  • Example 70 kg: about 2 L/day, e.g. 0.18% NaCl/4% glucose with 20 mmol K per litre, at about 83 ml/h. Reduce to 20 to 25 ml/kg/day if older, frail, renal or cardiac impairment.
  • Replace ongoing losses separately (vomiting, drains, high-output stoma).
  • Review fluids daily; stop once eating and drinking.
Steroid equivalents
DrugEquivalent to prednisolone 5 mg
Hydrocortisone20 mg
Prednisolone5 mg
Methylprednisolone4 mg
Dexamethasone0.75 mg

Glucocorticoid equivalence only. Hydrocortisone also has mineralocorticoid effect; dexamethasone has none.

Arrhythmias

Answer the questions; the tool lands you on the right RCUK 2021 algorithm.

Algorithms

First steps for any arrhythmia
  1. A to E, O2 if hypoxic, IV access, monitor with defib pads available.
  2. 12-lead ECG if it doesn't delay treatment. Record a rhythm strip during any intervention (adenosine, vagal, shocks).
  3. Bloods: K, Mg, Ca, glucose, troponin, TFT, VBG. Correct K to 4.0 to 5.0 and Mg above 1.0.
  4. Look for drivers: sepsis, hypovolaemia, hypoxia, pain, PE, ischaemia, thyroid, alcohol, drugs (QT prolongers, digoxin), line tips in the heart.
  5. Check for adverse features. Get help early.
Tachycardia with adverse featuresShock it
Do now
  1. Call for help (anaesthetics/ICU for sedation if conscious). Pads on.
  2. Synchronised DC cardioversion, up to 3 attempts. Press SYNC and check the markers sit on the R waves. Re-select SYNC before every shock: many defibrillators default back to unsynchronised.
  3. If 3 shocks fail: amiodarone 300 mg IV over 10 to 20 min, re-attempt cardioversion, then amiodarone 900 mg over 24 h.
RhythmStarting energy (biphasic)
Broad-complex (VT)120 to 150 J, escalate
AFConsider maximum output from the first shock
Atrial flutter, regular narrow (SVT)70 to 120 J, escalate

Check your defibrillator; manufacturers differ. Pulseless at any point: ALS, unsynchronised shocks.

Broad-complex regular (VT until proven otherwise)
Stable
  • Amiodarone 300 mg IV over 10 to 60 min, then 900 mg over 24 h (central line preferred for the infusion).
  • Correct K and Mg. 12-lead ECG. Cardiology review.
  • Known SVT with bundle branch block (old ECG proves it): treat as narrow regular (adenosine).
  • Deteriorates: synchronised DC cardioversion.

VT vs SVT with aberrancy: VT is more likely if

  • History of IHD, MI or heart failure (strongest predictor; over 90% are VT).
  • AV dissociation (P waves marching through), fusion or capture beats.
  • QRS very broad (above 160 ms), extreme axis (northwest), concordance across chest leads.
  • Morphology unlike a typical RBBB/LBBB.

Treating SVT as VT is safe; treating VT as SVT (verapamil) can kill. Never give verapamil to a broad-complex tachycardia.

Broad-complex irregularGet help

AF with bundle branch block

Treat as AF (narrow irregular).

Pre-excited AF (WPW)

Avoid AV node blockersVery fast (often above 200), irregular, QRS width varies beat to beat. Adenosine, digoxin, verapamil, diltiazem and beta-blockers can push it into VF. Synchronised cardioversion is safest; drug options (e.g. flecainide) only with cardiology.

Polymorphic VT / torsades de pointes

Do now
  • Magnesium sulfate 2 g IV over 10 min.
  • Stop all QT-prolonging drugs (macrolides, quinolones, ondansetron, haloperidol, methadone, antipsychotics, amiodarone, citalopram). Correct K (aim above 4.5).
  • Recurrent: overdrive pacing or isoprenaline (if bradycardia-dependent) with cardiology.
  • Pulseless or very unstable: defibrillate (unsynchronised).
Narrow-complex regular (SVT, flutter)
Stable: step by step
  1. Modified Valsalva: semi-recumbent, blow into a 10 ml syringe to move the plunger for 15 s, then lie flat and lift legs to 45 degrees for 15 s. Carotid massage only if no bruit and no stroke/TIA history.
  2. Adenosine 6 mg rapid IV bolus into a large proximal vein with a 20 ml saline flush. If no effect: 12 mg, then 18 mg. Rhythm strip running.
  3. Fails or contraindicated: verapamil 2.5 to 5 mg IV over 2 min, or a beta-blocker (e.g. metoprolol 5 mg IV, up to 15 mg).
  4. Still not converting or deteriorates: synchronised DC cardioversion.
Adenosine cautions
  • Warn the patient: brief chest tightness and sense of doom.
  • Avoid in severe asthma. Lower dose (3 mg) via central line, after heart transplant, or on dipyridamole/carbamazepine.
  • No verapamil if on beta-blockers or poor LV.

Atrial flutter: sawtooth waves, atrial rate about 300, often 2:1 block giving a regular rate of about 150. Adenosine reveals the flutter waves but rarely converts it. Rate control as AF; cardioversion works well at low energy; anticoagulate as AF.

Fast AF (narrow irregular): ward
UnstableSynchronised DC cardioversion (amiodarone if it fails or reverts).
Stable
  1. Treat the driver first: sepsis, dehydration, PE, alcohol, thyroid, electrolytes, pain. Many settle with this alone.
  2. Rate control (first-line): beta-blocker (e.g. bisoprolol 2.5 to 5 mg PO, metoprolol IV if needed) or diltiazem/verapamil if no heart failure.
  3. Heart failure or hypotension: digoxin (500 mcg IV/PO loading, repeat after 6 h, renal adjust) and/or amiodarone.
  4. Onset clearly under 48 h (or adequately anticoagulated): rhythm control is an option. Flecainide 2 mg/kg IV (max 150 mg) if no structural/ischaemic heart disease; amiodarone if structural disease; or DC cardioversion.
TargetResting HR below 110 initially (lenient), lower if still symptomatic.

Anticoagulation: calculate CHA2DS2-VASc (calculator) and bleeding risk. Start LMWH/DOAC at presentation if cardioversion may be planned. Over 48 h or unknown onset: 3 weeks of anticoagulation (or TOE) before elective cardioversion.

New AF in the ICU patientICU

Very common in septic, post-operative and shocked patients. Fix the drivers, shock if unstable, then rate or rhythm control by haemodynamics.

Fix the drivers (every patient)
  • K 4.0 to 5.0, Mg above 1.0 (2 g Mg alone converts some).
  • Hypoxia, hypercapnia, acidosis, fluid status (echo).
  • Sepsis source control. Pain, agitation, withdrawal, fever.
  • Reduce catecholamines where possible (adrenaline and dobutamine are proarrhythmic; vasopressin spares them).
  • Pull back a CVC or PA catheter sitting in the atrium/ventricle.
DrugDoseBest forWatch
Amiodarone300 mg IV over 20 to 60 min (central), then 900 mg/24 hOn vasopressors, poor LV, rhythm controlHypotension, bradycardia, QT; halves digoxin need; warfarin interaction
Beta-blockerMetoprolol 2.5 to 5 mg IV (to 15 mg); esmolol 500 mcg/kg load, 50 to 200 mcg/kg/min; landiolol where availableNot shocked, hyperadrenergic, post-opHypotension, bronchospasm
Digoxin500 mcg IV, repeat 250 to 500 mcg after 4 to 6 h (total about 0.75 to 1 mg)Heart failure, add-onSlow onset, toxicity in AKI and low K
Magnesium2 g IV over 15 to 30 minEveryone, adjunctAccumulates in AKI
Flecainide2 mg/kg IV (max 150 mg)Structurally normal heartContraindicated in IHD/poor LV; 1:1 flutter

Persisting beyond 48 h: discuss anticoagulation daily (stroke vs ICU bleeding risk; consultant decision).

Bradycardia
Adverse features present
  1. Atropine 500 mcg IV, repeat every 3 to 5 min to max 3 mg.
  2. No response: isoprenaline 5 mcg/min IV, or adrenaline 2 to 10 mcg/min IV. Alternatives: aminophylline, dopamine, glycopyrronium 200 mcg, glucagon (beta-blocker/CCB overdose).
  3. Transcutaneous pacing (sedation and analgesia). Confirm mechanical capture with a femoral pulse, not just spikes on the monitor.
  4. Transvenous pacing: cardiology.
No adverse features: risk of asystole?Recent asystole, Mobitz II, complete heart block with broad QRS, or pause above 3 s: cardiology review, likely pacing. Otherwise observe and treat the cause.

Causes

Inferior MI, drugs (beta-blockers, CCBs, digoxin, amiodarone, ivabradine), hyperkalaemia, hypothermia, hypothyroidism, raised ICP, hypoxia (especially in ventilated patients: check the tube), vagal (suction, vomiting), conduction disease.

Special cases

  • Heart transplant: atropine can cause paradoxical block; use aminophylline or isoprenaline.
  • Post-cardiac surgery: use epicardial wires.
  • Spinal cord injury: suctioning/turning can cause profound bradycardia; pre-treat with atropine or glycopyrronium.

ECG recognition

Rhythms and ECG patterns
PatternRecognise it by
1st degree blockPR above 200 ms, every P conducted
Mobitz I (Wenckebach)PR lengthens then a dropped beat; usually benign (AV node)
Mobitz IIFixed PR with sudden dropped beats; risk of asystole, needs pacing review
2:1 blockEvery other P not conducted; can't call I or II from the strip, treat as high risk if QRS broad
Complete heart blockP and QRS independent; narrow escape (junctional) or broad (ventricular, worse)
Atrial flutterSawtooth in II, III, aVF; ventricular rate about 150 with 2:1
AFIrregularly irregular, no P waves
AVNRTRegular narrow 140 to 250, P hidden or just after QRS
WPWShort PR, delta wave (slurred upstroke), broad QRS in sinus rhythm
Long QTQTc above 470 (men) / 480 (women); above 500 high torsades risk
HyperkalaemiaPeaked T → flat P, long PR → broad QRS → sine wave
HypokalaemiaFlat T, U waves, ST depression, long QU
Brugada (type 1)Coved ST elevation V1 to V2 with T inversion; syncope = cardiology
Posterior MIST depression and tall R in V1 to V3; do V7 to V9
PESinus tachycardia (most common), RV strain, RBBB, S1Q3T3 (uncommon)
PericarditisWidespread saddle ST elevation, PR depression

ICU

Ward round, ventilation, vasopressors and the problems that come up every day.

Ward round

Presenting a patient (systems)ICU
  1. One-liner: age, ICU day, reason for admission, key background, ceiling of care / TEP.
  2. Last 24 h: events, procedures, new problems.
  3. Neuro: sedation and doses, RASS target vs actual, CAM-ICU, pupils, analgesia.
  4. Resp: airway (ETT length at lips or trache), mode, FiO2, PEEP, Vt (ml/kg PBW), RR, Ppeak/Pplat, ABG, P/F, secretions, CXR, weaning plan.
  5. CVS: MAP, HR, rhythm, pressor doses and trend, lactate, fluid balance (24 h and cumulative), echo.
  6. Renal: urine ml/kg/h, creatinine trend, RRT details, K, Mg, PO4, Na.
  7. GI: feed vs target, aspirates, bowels, LFTs, stress ulcer prophylaxis.
  8. Haem: Hb, platelets, coag, VTE prophylaxis.
  9. ID: Tmax, WCC, CRP/PCT, cultures, antimicrobials (day x of y), line days.
  10. Endo: glucose, insulin, steroids.
  11. Lines, tubes, skin. Family and goals. Plan (numbered, owners).
FAST HUGS BID checklistTick

Ventilation

Ventilator basicsICU
TermMeaningTarget
VtTidal volume6 ml/kg PBW (4 to 8)
PEEPPressure held at end-expiration; recruits alveoli5 to 15+ by FiO2
PpeakPeak pressure (airways plus lung)Investigate if rising
PplatInspiratory hold pressure (alveolar)30 cmH2O or less
Driving pressurePplat minus PEEP15 or less
ComplianceVt / (Pplat minus PEEP)Normal about 50 to 100 ml/cmH2O
I:EInspiratory to expiratory time1:2; 1:3 to 1:5 if obstructive
Two levers
  • Oxygenation = FiO2 and mean airway pressure (PEEP, inspiratory time). To improve: FiO2, PEEP, recruit, prone, treat the cause.
  • CO2 clearance = minute ventilation (RR x Vt) and dead space. To lower CO2: RR first (watch auto-PEEP), then Vt within pressure limits.

Modes

ModeYou setVariesNote
Volume control (VC-AC)Vt, RR, flow, PEEPPressureGuaranteed Vt; easy Pplat
Pressure control (PC-AC / BIPAP)Pinsp, RR, Ti, PEEPVtVt falls if lungs stiffen or tube blocks: watch MV alarms
PRVC / AutoFlowTarget Vt, RRPressure per breathHybrid
Pressure support (CPAP-ASB)PS, PEEP, triggerRR, VtWeaning; patient triggers every breath; check apnoea backup
CPAPPEEPEverything elseSBT, post-extubation
APRVHigh/low pressure and timesVtRescue; consultant-led

After intubation (typical start)

  • Vt 6 to 8 ml/kg PBW (calculator), RR 14 to 20 (match prior MV if severe acidosis), PEEP 5, FiO2 1.0 then wean.
  • ABG at 20 to 30 min. CXR: tip 3 to 5 cm above carina. Note length at lips (often 21 to 23 cm). Cuff 20 to 30 cmH2O.
TargetsSpO2 92 to 96% (88 to 92% if chronic hypercapnia). PaO2 at least 8 kPa. pH above 7.25 with permissive hypercapnia unless raised ICP, pulmonary hypertension/RV failure. Brain injury: PaCO2 4.5 to 5.0, PaO2 above 10.

PEEP/FiO2 table (ARDSNet lower)

FiO20.30.40.50.60.70.80.91.0
PEEP55 to 88 to 101010 to 141414 to 1818 to 24
ARDSICU
  • Berlin: within 1 week, bilateral opacities not explained by effusion/collapse, not fully cardiac, P/F on PEEP 5 or more.
  • Severity (P/F kPa): mild 26.7 to 40, moderate 13.3 to 26.6, severe 13.3 or less.
  • Lung protection: Vt 6 ml/kg PBW, Pplat 30 or less, driving pressure 15 or less, PEEP by table.
  • Prone if P/F below 20 kPa: at least 12 h/day (PROSEVA used 16 h).
  • Neuromuscular blockade in early moderate/severe ARDS with asynchrony (consultant).
  • Conservative fluids once shock resolved.
  • ECMO referral for refractory hypoxaemia or hypercapnic acidosis (pH below 7.20) despite optimal care: discuss early.
Ventilated patient desaturating (DOPES)Emergency
Do now
  1. FiO2 1.0, call for help.
  2. Take them off the ventilator: hand-ventilate with Water's circuit / bag, 15 L O2. Feel the compliance.
  3. Look at the capnography trace: no trace = tube out or no cardiac output until proven otherwise.
  4. Pass a suction catheter. Won't pass = obstruction.
  5. Tube length at lips, cuff, bilateral air entry, chest movement.
  6. Better off the vent = ventilator/settings problem. Still bad = patient or tube.
CluesFix
DisplacementLength changed, EtCO2 lost, cuff leak, one-sided air entryPull back if endobronchial; if out: remove, bag-mask, reintubate (senior)
ObstructionHigh Ppeak, catheter stops, low Vt in PCSuction, lavage, bite block, unkink; change tube if needed
PneumothoraxHigh Pplat, one-sided, hypotensionFinger/needle thoracostomy then drain
EquipmentAlarms, disconnection, O2 supply, wet HMEHand-ventilate, check circuit, replace HME
Stacking (auto-PEEP)Asthma/COPD, high RR, falling BPDisconnect to exhale, press chest, lower RR, longer expiration

High-pressure alarm

  • Do an inspiratory hold to get Pplat.
  • High Ppeak, normal Pplat (gap above 10) = airway resistance: kink, biting, secretions, bronchospasm, small tube.
  • High Ppeak and high Pplat = stiff respiratory system: pneumothorax, endobronchial tube, collapse, oedema, ARDS, effusion, abdominal compartment, fighting the vent.

Low-pressure / low-volume alarm

Disconnection or leak, cuff leak (cuff at the cords: senior), bronchopleural fistula, patient effort falling in PS.

Hypoxia, high CO2 and asynchronyICU

Hypoxaemia (not peri-arrest)

  1. Real? Probe, ABG. Exclude DOPES.
  2. FiO2 and PEEP up (table).
  3. Cause: CXR and lung USS for collapse, consolidation, effusion, pneumothorax, oedema; think PE.
  4. Suction, physio, bronchoscopy for lobar collapse. Diurese if wet.
  5. Recruit, prone, paralyse (senior). ECMO if refractory.

Hypercapnia

  1. Is the minute volume actually delivered (leak, falling Vt in PC)?
  2. RR up (watch auto-PEEP), then Vt within limits.
  3. Cut dead space (short catheter mount, heated humidifier instead of HME).
  4. Bronchospasm, secretions, more CO2 production (fever, overfeeding, shivering).
  5. Accept if pH above 7.20 to 7.25 and no contraindication.

Asynchrony

TypeLooks likeFix
Ineffective triggerEfforts without breathsTreat auto-PEEP, add PEEP, more sensitive trigger, less PS/sedation
Auto-triggerBreaths without effortFix leak/water, less sensitive trigger
Double triggerTwo breaths stackedLonger Ti or bigger Vt, or switch to PS
Flow starvationScooped pressure curve (VC)More flow or pressure mode
Cycling problemsPatient exhales against ventAdjust cycle-off (ETS) in PS

Capnography

  • Flat: tube out, blocked, disconnected, arrest.
  • Shark fin: bronchospasm.
  • Gradual fall: falling cardiac output, PE, hyperventilation.
  • Sudden rise: ROSC.
  • Curare cleft: patient effort.

Fighting the vent: look for a cause first (hypoxia, CO2, pain, bladder, tube, pneumothorax, delirium), then settings, then sedation, then paralysis last.

Tracheostomy emergency and accidental extubationEmergency
Tracheostomy (NTSP)
  1. Call airway help. High-flow O2 to face and trache. Capnography.
  2. Remove inner cannula. Pass a suction catheter.
  3. Won't pass: deflate the cuff.
  4. Still not breathing well: remove the trache.
  5. Oxygenate via mouth/face (cover stoma) or via stoma (paediatric mask or LMA on stoma).

Laryngectomy patients cannot be oxygenated from the face: stoma only. Check the bed-head sign (green = trache, red = laryngectomy).

Accidental extubation: face mask O2, bag-mask with adjuncts if needed, senior airway help; some will cope without reintubation.

Weaning and extubationTick

Ready for an SBT?

SBT: 30 to 120 min on PS 5 to 8 / PEEP 5, or CPAP.

Failure: RR above 35, SpO2 below 90%, HR above 140 or 20% change, SBP above 180 or below 90, agitation, sweating, accessory muscles, rising CO2. RSBI (RR / Vt in L) above 105 predicts failure (calculator).

Before extubating

HFNO, CPAP and NIV quick reference
  • HFNO: 30 to 60 L/min, titrate FiO2. ROX = (SpO2/FiO2)/RR; 4.88 or more at 2, 6, 12 h suggests success; falling ROX means plan intubation (calculator).
  • CPAP: type 1 failure (pulmonary oedema, pneumonia); starts 5 to 10 cmH2O.
  • NIV (BiPAP): type 2 failure (COPD, obesity hypoventilation, neuromuscular); see COPD card.
  • Decide and document what happens if it fails before you start.
Intubation (RSI) checklistICU

Senior anaesthetic/ICU procedure. Your job is often to prepare and support.

DrugTypical doseNote
Ketamine1 to 2 mg/kg (less if shocked)Haemodynamically kinder
Propofol1 to 2.5 mg/kg (much less if shocked)Hypotension
Fentanyl1 to 3 mcg/kgOmit or reduce if shocked
Rocuronium1 to 1.2 mg/kgSugammadex reverses
Suxamethonium1.5 mg/kgAvoid in hyperkalaemia, burns over 24 h, crush, neuromuscular disease

Post-intubation hypotension is common: induction drugs, positive pressure, hypovolaemia, auto-PEEP, tension. Fluids, pressor, check DOPES.

Circulation

Vasopressors and inotropesICU
TargetsMAP 65 for most (SSC 2021). Higher (70 to 80) may help in chronic hypertension if urine output improves; 60 to 65 acceptable in older patients (65 trial).
DrugActionTypical doseNotes
NoradrenalineAlpha-1 more than beta-10.01 to 0.5 mcg/kg/min (more in refractory)First line in septic shock. Central ideally; short-term dilute peripheral per local policy
VasopressinV10.01 to 0.04 units/min (often 0.03)Add at noradrenaline 0.25 to 0.5. Watch digital/gut ischaemia
AdrenalineBeta-1, beta-2, alpha-10.01 to 0.5 mcg/kg/minInotrope and pressor. Raises lactate and glucose; arrhythmias
DobutamineBeta-1 more than beta-22.5 to 20 mcg/kg/minLow output. Can drop BP; arrhythmias
MilrinonePDE3 inhibitor0.375 to 0.75 mcg/kg/minRenally cleared, long half-life, hypotension. RV failure
MetaraminolAlpha-10.5 to 1 mg boluses; infusion per localPeripheral bridge. Reflex bradycardia
PhenylephrinePure alpha-150 to 100 mcg bolusesBridge
EphedrineMixed3 to 6 mg bolusesGood if also bradycardic
HydrocortisoneSteroid50 mg IV 6-hourly or 200 mg/24 hStart when noradrenaline/adrenaline 0.25 mcg/kg/min or more for 4 h (SSC 2021)
Methylene blueNO pathway1 to 2 mg/kgRefractory vasoplegia; consultant. Serotonin syndrome with SSRIs

Convert doses with the infusion converter.

Rising requirement: check in this order

  1. Real? Art line damped, zeroed, transducer at phlebostatic axis (4th ICS mid-axillary). Fast-flush test.
  2. Drug going in? Syringe empty or mid-changeover, line occluded or disconnected, shared lumen, extravasation.
  3. New cause? Sepsis/new source, bleeding, sedation bolus, new AF, tamponade, pneumothorax, auto-PEEP, adrenal insufficiency, anaphylaxis, abdominal compartment, low ionised Ca.
  4. Check: ABG with lactate, iCa, Hb; ECG; echo; cultures; CXR.
  5. Act: fluid if responsive, vasopressin, hydrocortisone, inotrope if poor LV, source control, consultant.

Practical

  • Never flush a pressor line. Dedicated lumen. Double-pump changeovers.
  • Wean adrenaline/dobutamine first, then noradrenaline, vasopressin last (stopping it first causes rebound hypotension).
  • Art line: overdamped (bubble, clot, kink) flattens trace and under-reads systolic; underdamped is spiky and over-reads systolic. MAP is the most reliable number.
  • Extravasation: stop, leave cannula, aspirate, elevate, mark, senior, phentolamine per local protocol.

Daily problems

Sedation, analgesia and deliriumICU

Analgesia first, then sedation. Target RASS 0 to -2 unless there is a reason (raised ICP, paralysed, status).

DrugInfusionWatch
Propofol1 to 4 mg/kg/hHypotension, triglycerides, pancreatitis, PRIS (above 4 mg/kg/h for 48 h: acidosis, rhabdo, arrhythmia). 1.1 kcal/ml
Alfentanil/fentanyl/remifentanilPer protocolAccumulation (fentanyl), ileus
MidazolamPer protocolAccumulates, more delirium
Dexmedetomidine0.2 to 1.4 mcg/kg/hBradycardia, hypotension
Clonidine0.5 to 2 mcg/kg/hBradycardia, hypotension, rebound

RASS

ScoreDescription
+4Combative
+3Very agitated, pulls tubes
+2Agitated, fights vent
+1Restless
0Alert and calm
-1Drowsy, wakes to voice above 10 s
-2Light sedation, wakes to voice below 10 s
-3Moderate, movement to voice, no eye contact
-4Deep, movement to touch only
-5Unrousable

Delirium (CAM-ICU positive)

  1. Cause: hypoxia, CO2, sepsis, pain, retention, constipation, withdrawal (alcohol, nicotine, benzos, SSRIs), Na, glucose, Ca, urea, ammonia, drugs (benzos, anticholinergics, steroids), new neurology.
  2. Non-drug: orientation, glasses and hearing aids, sleep, mobilise, family.
  3. Drugs only for distress or danger: haloperidol 0.5 to 2.5 mg (check QTc, not in Parkinson's/Lewy body), quetiapine 25 to 50 mg BD, dexmedetomidine/clonidine.
New fever on ICUICU

Infective: VAP, line (CRBSI), urine, C. difficile, abdominal collection, wound, sinusitis, acalculous cholecystitis, endocarditis, post-neurosurgical meningitis.

Non-infective: drugs, transfusion, VTE, pancreatitis, withdrawal, NMS, serotonin syndrome, adrenal crisis, thyroid.

Do
  • Examine everything including line sites and skin.
  • Cultures: peripheral plus each lumen of a suspect line, tracheal aspirate/BAL, urine, stool if diarrhoea. CXR. USS/CT for collections.
  • Remove unneeded or suspect lines.
  • Antibiotics per Microguide, check previous micro (MRSA, ESBL, CPE). Set duration and review date.

VAP bundle: head up 30 to 45, sedation hold, SBT, subglottic drainage, cuff 20 to 30, oral care.

Oliguria, AKI and RRT on ICUICU
  1. Catheter: flush, bladder scan, kinks.
  2. Perfusion: MAP at target, fluid responsive, cardiac output.
  3. Drugs: nephrotoxins off, renally dose everything.
  4. Intra-abdominal pressure if distended (above 12 IAH; above 20 with organ failure = abdominal compartment syndrome).
  5. USS if obstruction possible; urine dip, CK.

CVVHDF troubleshooting

  • Filter clotting: access line (swap/reposition), anticoagulation, blood flow, too much fluid removal.
  • Citrate accumulation: total/ionised Ca ratio above 2.5, rising anion gap, acidosis, falling iCa (liver failure, shock). Reduce or stop citrate.
  • RRT removes drugs (antibiotic doses), PO4, Mg, and cools the patient.
  • Typical effluent dose 20 to 25 ml/kg/h.
Nutrition and GI on ICUICU
  • Enteral feed within 24 to 48 h if gut usable; trophic if shocked.
  • Refeeding risk (low BMI, little intake, alcohol, low K/Mg/PO4): start 10 kcal/kg/day (5 if extreme), thiamine/Pabrinex first, replace PO4, K, Mg daily.
  • High aspirates: check NG, cut opioids, fix electrolytes and glucose, treat constipation; metoclopramide 10 mg IV TDS and/or erythromycin 100 to 250 mg IV BD to TDS (short course, QTc); consider NJ.
  • Stress ulcer prophylaxis if high risk (coagulopathy, shock, ventilated over 48 h, previous GI bleed). Stop when fed and lower risk.
  • Laxatives from day 2 to 3. Diarrhoea: C. difficile, laxatives, feed, antibiotics.
  • Distension: ileus, obstruction, ischaemia (lactate, pain), compartment syndrome, toxic megacolon.
Haematology on ICUICU
  • Transfuse at Hb 70 for most (TRICC); around 80 in active ACS.
  • Platelet thresholds depend on procedure: commonly 50 for most procedures, 100 for neurosurgery/CNS bleeding; check BSH/local for lines and LP.
  • Low platelets: sepsis, DIC, dilution, drugs (linezolid, heparin, beta-lactams), HIT, TTP/HUS, RRT, liver, ECMO.
  • HIT: fall above 50% 5 to 10 days after heparin, thrombosis. 4Ts (calculator). Intermediate/high: stop all heparin (flushes and RRT too), send PF4, non-heparin anticoagulant (argatroban) with haematology.
  • VTE prophylaxis: enoxaparin 40 mg OD (adjust for weight/renal) or IPC if bleeding risk.
Lines, tubes and drainsICU
  • Every day: still needed? Day count? Site clean?
  • CVC tip at cavo-atrial junction/lower SVC on CXR before routine use. Remove patient flat or head-down, occlude site. Air embolism: left lateral head-down, 100% O2.
  • ETT cuff 20 to 30 cmH2O each shift; length documented.
  • Chest drains: swinging, bubbling, draining? Never clamp a bubbling drain.
  • NG: confirm position (pH aspirate or X-ray) before every use per NPSA.
Electrolytes on ICUICU
  • K 4.0 to 5.0 and Mg above 1.0 in anyone with arrhythmia risk. Central KCl per unit protocol (e.g. 20 mmol in 50 ml over 1 h).
  • Low ionised Ca (below about 1.0): common with citrate and massive transfusion; calcium chloride centrally or gluconate.
  • Hypernatraemia: fall no more than about 10 mmol/L per 24 h. Free water via NG, 5% glucose; cut sodium load (fluids, bicarbonate, drug diluents). Large dilute urine volumes: think diabetes insipidus.
  • Hyponatraemia: see card.
Goals of care, family, donation
  • Clarify ceiling of care and TEP/ReSPECT early, especially frail or multimorbid patients, and before starting NIV.
  • Document family updates and who was present.
  • Deteriorating despite maximal treatment: raise it with the consultant so the conversation happens before a crisis.
  • End of life on ICU: refer to the specialist nurse for organ donation (SNOD) per local criteria.

Tools

Calculators and quick reference. Numbers stay on this device.

Calculators

Infusion converterml/h ↔ dose
Enter a rate.
Enter a target to get ml/h.

Concentrations vary by unit. Check the syringe label, not the preset.

Predicted body weight and tidal volume
Enter height.

Male 50 + 0.91 × (height − 152.4). Female 45.5 + 0.91 × (height − 152.4).

ABG helper
Fill in what you have.
NEWS2
Enter all parameters.
Glasgow Coma Scale
CURB-65
Wells score for PE (two-level)
CHA2DS2-VASc
4Ts (HIT probability)
Creatinine clearance (Cockcroft-Gault)
Used for DOAC and many drug doses (BNF uses CrCl, not eGFR, for these).
Corrected calcium

Corrected Ca = Ca + 0.02 × (40 − albumin). Use ionised Ca on ICU where available.

Lung mechanics and perfusion

Driving pressure and compliance

MAP and CPP

RSBI (weaning)
ROX index (HFNO)

Reference

ABG interpretation in 7 steps
  1. Oxygenation: PaO2 against FiO2. Rough rule: PaO2 should be about FiO2% minus 10 kPa. P/F normal above 40 kPa.
  2. pH: acidaemia below 7.35, alkalaemia above 7.45.
  3. Primary process: CO2 (respiratory) or HCO3/BE (metabolic).
  4. Compensation: Winter's for metabolic acidosis (expected PaCO2 kPa ≈ (1.5 × HCO3 + 8) / 7.5 ± 0.3).
  5. Anion gap = Na − (Cl + HCO3); normal 8 to 12. Add about 2.5 per 10 g/L albumin below 40.
  6. Raised AG: lactate, ketones, renal failure, toxins (methanol, ethylene glycol, salicylate, pyroglutamic acid). Normal AG: saline, diarrhoea, RTA, ureteric diversion, acetazolamide.
  7. Lactate: type A (hypoperfusion) vs type B (adrenaline, metformin, liver failure, thiamine deficiency, seizures, malignancy).
Normal values (adult, approximate)
TestRange
pH7.35 to 7.45
PaO2 (air)10 to 13 kPa
PaCO24.7 to 6.0 kPa
HCO322 to 26 mmol/L
Base excess−2 to +2
Lactatebelow 2 mmol/L
Na135 to 145
K3.5 to 5.3
Urea2.5 to 7.8
Creatinineabout 60 to 110 µmol/L
Corrected Ca2.2 to 2.6
Ionised Ca1.1 to 1.3
Mg0.7 to 1.0
PO40.8 to 1.5
HbM 130 to 180, F 115 to 165 g/L
Platelets150 to 400
WCC4 to 11
Neutrophils2 to 7.5
INR0.8 to 1.2
Fibrinogen1.5 to 4 g/L
Osmolality275 to 295 mOsm/kg
Glucose (fasting)4 to 7
QTcbelow 450 (M), 460 (F)

Your lab's ranges take priority.

When to call your senior now
  • Any peri-arrest situation, arrest, need for cardioversion or pacing.
  • NEWS2 7 or more, or rising despite treatment.
  • Airway threat, GCS 8 or less or falling, new focal neurology, blown pupil, status.
  • Rapidly rising O2 or pressor needs. Lactate 4 or more.
  • Major bleeding. K 6.5 or more. pH below 7.15.
  • You are worried, or the family is worried. That counts.

SBAR: Situation (who, where, what now), Background, Assessment (A to E, NEWS, your worry), Recommendation (what you need and by when).