Critical care: common problems, ethics and recovery

• Common ICU problems: Delirium in Critical Care | ICU-acquired Infection and Antimicrobial Stewardship | ICU-acquired Weakness | Electrolyte Problems in ICU | GI Bleeding, Pancreatitis and Liver Failure in ICU
• Neurocritical care: Traumatic Brain Injury and Raised ICP | Post-cardiac Arrest Care and Prognostication | Status Epilepticus and Other Neurological Emergencies
• Ethics and end of life: Treatment Decisions, Capacity and Best Interests | Withdrawal of Treatment and End-of-life Care | Death by Neurological Criteria | Organ Donation | Communication with Families
• Recovery: Post-intensive Care Syndrome and Rehabilitation
• Revision: ICU Problems and Ethics at a Glance | Spot the Diagnosis | Exam-style Scenarios | Key Points | Guidelines and Further Reading

🕊️ Critical care — common problems, ethics and recovery — page 5 of the Anaesthetics and Critical Care chapter. Once a patient is on the unit, the challenges shift to preventing harm (delirium, infection, weakness), managing brain injury, and — for about 1 in 5 patients — caring well for them at the end of life. Survivors often face months of physical, cognitive and psychological recovery. Exams test the law and ethics here as much as the medicine.
Your four questions for every patient on ICU: Is the patient getting better, the same, or worse — and why? What harm can I prevent today (delirium, infection, weakness, lines, drugs)? Is the treatment still in the patient's best interests — and do the family understand? What will recovery look like — and what support will they need after discharge?

Delirium in Critical Care

• Common — affects up to 80% of ventilated patients; linked to longer ventilation and stay, higher mortality and long-term cognitive impairment.
• Types — hypoactive (quiet, withdrawn — commonest and most often missed), hyperactive (agitation, pulling at lines), mixed.
• Screening — CAM-ICU (Confusion Assessment Method for ICU) at least once a shift:
  • 1. Acute change or fluctuation in mental status, and
  • 2. Inattention (e.g. squeezing the hand on the letter "A" in a sequence), plus either
  • 3. Altered level of consciousness (RASS not 0), or
  • 4. Disorganised thinking.
• Risk factors — age, dementia, alcohol, severity of illness, benzodiazepines, anticholinergics, sepsis, hypoxia, metabolic disturbance, sleep deprivation, immobility, restraints.
• Prevention and management:
  • Treat causes (infection, hypoxia, electrolyte and glucose problems, urinary retention, constipation, pain, withdrawal — alcohol, nicotine, drugs).
  • Minimise sedation — avoid benzodiazepines; prefer propofol or dexmedetomidine; daily sedation holds.
  • Non-drug — orientation (clocks, calendars), glasses and hearing aids, family visits, day–night routine (light, noise reduction, eye masks and earplugs), early mobilisation.
  • Drugs — haloperidol or atypical antipsychotics don't shorten delirium (MIND-USA, AID-ICU) — use only short term for distress or danger; dexmedetomidine for agitated delirium preventing weaning.
• Alcohol withdrawal in ICU — benzodiazepines (symptom-triggered), thiamine (Pabrinex) before glucose; phenobarbital or dexmedetomidine as adjuncts.

ICU-acquired Infection and Antimicrobial Stewardship

• Why ICU patients get infections — invasive devices (tubes, lines, catheters), immunosuppression of critical illness, broad-spectrum antibiotics, prolonged stay.
• Device-related infections:

  Infection	Features	Prevention
  Ventilator-associated pneumonia (VAP)	New infiltrate, fever, purulent secretions, worsening oxygenation after 48 hours of ventilation	Head up 30–45°, sedation holds, subglottic drainage, oral care, cuff pressure, early extubation
  Central line–associated bloodstream infection (CLABSI)	Fever, positive blood cultures (Staph. epidermidis, Staph. aureus, Gram-negatives, Candida)	Insertion bundle (hand hygiene, full barrier precautions, chlorhexidine skin prep, ultrasound, avoid femoral), daily review — remove when not needed
  Catheter-associated UTI	Fever, positive urine culture (colonisation is common — don't treat asymptomatic bacteriuria)	Remove catheters early; aseptic insertion
  C. difficile	Diarrhoea, colitis, toxic megacolon	Antibiotic stewardship, isolation, hand washing with soap (alcohol gel doesn't kill spores)

• Multidrug-resistant organisms — MRSA, ESBL-producing Enterobacterales, carbapenemase-producing Enterobacterales (CPE), VRE, Pseudomonas, Acinetobacter, Candida auris — screening, isolation, contact precautions.
• Fungal infection — invasive candidiasis (risk — TPN, abdominal surgery, broad-spectrum antibiotics, central lines), invasive aspergillosis (immunosuppressed, severe influenza and COVID-19).
• Antimicrobial stewardship ("Start Smart — Then Focus", UKHSA):
  • Take cultures before antibiotics (without delaying treatment in sepsis).
  • Start appropriate empirical antibiotics promptly; document indication and review date.
  • Review at 48–72 hours — stop, switch (IV to oral), change (narrow the spectrum to cultures), continue, or OPAT.
  • Short courses where evidence supports (e.g. 5–7 days for many infections); procalcitonin can guide stopping.
  • Therapeutic drug monitoring (vancomycin, gentamicin) and dose adjustment for RRT and augmented renal clearance.
• Selective decontamination of the digestive tract (SDD) — topical and enteral antibiotics to prevent VAP — used in some units (SuDDICU trial — no mortality benefit in its main analysis).

ICU-acquired Weakness

• ICU-acquired weakness (ICUAW) — generalised, symmetrical weakness developing during critical illness with no other cause — affects about half of patients ventilated for over a week.
• Types:
  • Critical illness polyneuropathy — axonal sensorimotor neuropathy — distal weakness, reduced reflexes, sensory loss.
  • Critical illness myopathy — proximal weakness, normal sensation, raised or normal CK; linked to steroids and neuromuscular blockers.
  • Often both (critical illness polyneuromyopathy).
• Risk factors — sepsis and multi-organ failure, prolonged ventilation and immobility, hyperglycaemia, corticosteroids, neuromuscular blockers, deep sedation.
• Features — difficulty weaning, flaccid weakness of limbs (face usually spared), reduced reflexes; MRC sum score under 48/60 defines ICUAW.
• Differential diagnosis — Guillain–Barré syndrome, myasthenia, spinal cord lesion, electrolytes (hypokalaemia, hypophosphataemia, hypermagnesaemia), drug effects (residual neuromuscular block).
• Investigations — nerve conduction studies and EMG, CK; muscle biopsy rarely.
• Prevention and management — treat sepsis, avoid hyperglycaemia, limit steroids and neuromuscular blockers, minimise sedation, early mobilisation and physiotherapy (sitting, standing, cycle ergometry — even when ventilated), nutrition; recovery over weeks to months (neuropathy recovers more slowly).
• Diaphragm dysfunction — ventilator-induced diaphragmatic dysfunction from prolonged controlled ventilation — contributes to weaning failure.

Electrolyte Problems in ICU

• Diabetes insipidus after brain injury — large volumes of dilute urine (over 3 L a day, urine osmolality under 300), rising sodium — desmopressin (DDAVP); common in brain stem death (also manage for organ donation).
• SIADH vs cerebral salt wasting (both cause hyponatraemia after SAH) — SIADH — euvolaemic (fluid restrict); cerebral salt wasting — hypovolaemic (replace salt and water — don't fluid restrict in SAH — vasospasm risk; fludrocortisone).

GI Bleeding, Pancreatitis and Liver Failure in ICU

• Upper GI bleeding — resuscitate (restrictive transfusion — Hb 70–80), correct coagulopathy, endoscopy within 24 hours (immediately after resuscitation if unstable); variceal bleeding — terlipressin and antibiotics, band ligation; balloon tamponade (Sengstaken–Blakemore) as a bridge; TIPSS; airway protection (intubation) for massive haematemesis or encephalopathy.
• Severe acute pancreatitis:
  • Persistent organ failure over 48 hours (revised Atlanta classification) — ICU.
  • Goal-directed fluids (avoid over-resuscitation — WATERFALL trial), analgesia, early enteral nutrition (NG or NJ), no routine prophylactic antibiotics.
  • Complications — ARDS, AKI, abdominal compartment syndrome, infected necrosis (step-up approach — antibiotics, percutaneous or endoscopic drainage, necrosectomy), pseudocysts, splenic vein thrombosis.
  • Gallstone pancreatitis with cholangitis — urgent ERCP.
• Acute liver failure (jaundice, coagulopathy — INR over 1.5 — and encephalopathy in a patient without chronic liver disease):
  • Causes — paracetamol (commonest in UK), viral hepatitis (A, B, E), drugs (antituberculous, idiosyncratic), autoimmune, Wilson's, Budd–Chiari, ischaemic, pregnancy (AFLP, HELLP).
  • Management — early discussion with a liver transplant centre (King's College criteria), N-acetylcysteine (paracetamol — and some non-paracetamol causes), intubation for grade 3–4 encephalopathy, cerebral oedema management (target sodium 145–150, avoid hypercapnia, treat fever, ammonia monitoring), glucose monitoring (hypoglycaemia), infection screening, avoid FFP unless bleeding (INR is a prognostic marker), RRT for ammonia and acidosis.
  • King's College criteria (paracetamol) — arterial pH under 7.30 after fluid resuscitation, or all of — INR over 6.5, creatinine over 300 µmol/L and grade 3–4 encephalopathy (lactate over 3.5 after fluids added in modified criteria).
• Acute-on-chronic liver failure — decompensated cirrhosis with organ failure — high mortality; ICU decisions consider transplant candidacy and reversibility.

Traumatic Brain Injury and Raised ICP

• Primary injury (at impact) can't be reversed; ICU care aims to prevent secondary brain injury — from hypoxia, hypotension, hypercapnia, hypocapnia, hyperthermia, hypo- or hyperglycaemia, hyponatraemia, seizures and raised ICP.
• Monro–Kellie doctrine — the skull is a fixed box containing brain, blood and CSF; a rise in one must be offset by the others or ICP rises.
• Cerebral perfusion pressure (CPP) = MAP – ICP — target CPP 60–70 mmHg; ICP under 20–22 mmHg (Brain Trauma Foundation).
• Signs of raised ICP — headache, vomiting, falling GCS, Cushing's triad (hypertension, bradycardia, irregular breathing — late), dilated unreactive pupil (uncal herniation — 3rd nerve), papilloedema (late).
• "Neuroprotective" ICU care:
  • Intubate if GCS 8 or less (or falling, agitation, seizures); avoid hypoxia (SpO₂ over 94%; PaO₂ over 13 kPa) and hypotension (systolic over 110 mmHg or MAP over 80–90).
  • PaCO₂ 4.5–5.0 kPa (avoid prolonged hyperventilation — cerebral vasoconstriction causes ischaemia; brief hyperventilation only as a bridge for herniation).
  • Head up 30°, neutral neck, tube ties not compressing jugular veins.
  • Adequate sedation and analgesia (propofol, opioids); neuromuscular blockade if needed.
  • Normothermia, glucose 6–10, sodium 140–145 (avoid hyponatraemia).
  • Seizure prophylaxis (levetiracetam or phenytoin for 7 days in severe TBI — prevents early seizures).
  • Osmotherapy for raised ICP — mannitol (0.5–1 g/kg) or hypertonic saline.
  • ICP monitoring (intraparenchymal bolt or external ventricular drain — also drains CSF).
  • Refractory raised ICP — deeper sedation, barbiturate coma, decompressive craniectomy (RESCUEicp — reduced mortality but more survivors with severe disability).
• Neurosurgery — extradural and acute subdural haematomas with mass effect need urgent evacuation.
• Steroids — no role in TBI (CRASH trial — increased mortality); tranexamic acid within 3 hours in mild to moderate TBI (CRASH-3).

⚠️ Safety Pearl: A single episode of hypotension (systolic under 90) or hypoxia doubles mortality after traumatic brain injury. Protecting MAP, oxygenation and CO₂ — especially during intubation and transfer — matters as much as surgery.

Post-cardiac Arrest Care and Prognostication

• Post-resuscitation care (RCUK/ERC 2021):
  • Airway and breathing — SpO₂ 94–98% (avoid hyperoxia and hypoxia), normocapnia (PaCO₂ 4.5–6.0 kPa), lung-protective ventilation.
  • Circulation — 12-lead ECG; urgent coronary angiography for STEMI (and consider for suspected cardiac cause without STEMI if unstable); MAP over 65 mmHg; echo.
  • Temperature control — prevent fever (keep 37.5°C or less) for at least 72 hours in comatose patients (TTM2 — no benefit of 33°C over normothermia).
  • Glucose 6–10; treat seizures (EEG); avoid hypotension; sedation.
  • Find and treat the cause (the 4 Hs and 4 Ts — CT head and CTPA as needed).
• Neurological prognostication — delay until at least 72 hours after return of spontaneous circulation (ROSC), once sedation has cleared and confounders (hypothermia, drugs, metabolic) are excluded; use a multimodal approach:
  • Clinical — absent pupillary and corneal reflexes at 72 hours or more; status myoclonus within 72 hours.
  • Biomarkers — high neuron-specific enolase (NSE) (over 60 µg/L at 48–72 hours).
  • Neurophysiology — EEG (suppressed or burst-suppression background), bilateral absent N20 waves on somatosensory evoked potentials (SSEP).
  • Imaging — CT (loss of grey–white differentiation) or MRI (diffuse diffusion restriction).
  • Poor outcome is "likely" if two or more of these are present (ERC/ESICM algorithm).
• Survivors — assess for cognitive problems, emotional problems and fatigue; cardiac rehabilitation; ICD if indicated; follow-up.
• Self-fulfilling prophecy — premature withdrawal based on early signs can cause avoidable deaths; avoid prognostication on a single test.

Status Epilepticus and Other Neurological Emergencies

• Refractory status epilepticus — seizures continuing despite a benzodiazepine and a second-line drug (levetiracetam, phenytoin or valproate) — general anaesthesia (propofol, midazolam infusion or thiopental) with intubation, continuous EEG monitoring (aim for seizure suppression or burst suppression for 24–48 hours), then slowly wean; look for causes (autoimmune encephalitis, infection, drugs, structural lesions).
• Non-convulsive status — reduced consciousness without obvious seizures — EEG; common after cardiac arrest, in sepsis and brain injury.
• Subarachnoid haemorrhage on ICU:
  • Secure the aneurysm early (coiling or clipping).
  • Nimodipine 60 mg 4-hourly for 21 days (reduces delayed cerebral ischaemia).
  • Delayed cerebral ischaemia (vasospasm — days 3–14) — new deficit or falling GCS — maintain euvolaemia, induced hypertension, endovascular therapy.
  • Hydrocephalus (EVD), hyponatraemia, seizures, neurogenic pulmonary oedema and stunned myocardium (takotsubo-like).
• Guillain–Barré syndrome and myasthenic crisis — monitor FVC; ICU for respiratory or bulbar failure; IVIG or plasma exchange; autonomic instability in GBS.
• Bacterial meningitis and encephalitis — antibiotics and aciclovir, dexamethasone, raised ICP management.
• Spinal cord injury — neurogenic shock (hypotension with bradycardia — vasopressors and atropine), respiratory failure with high cervical injuries (C3–5 — phrenic nerve), autonomic dysreflexia later.

Treatment Decisions, Capacity and Best Interests

• Key principles (GMC "Treatment and care towards the end of life" 2010 and "Decision making and consent" 2020):
  • Doctors are not obliged to provide treatment that isn't clinically appropriate — patients and families can't demand it, but the decision should be explained and a second opinion offered.
  • An adult with capacity can refuse any treatment, including life-sustaining treatment.
  • Withholding and withdrawing treatment are ethically and legally equivalent.
• Mental Capacity Act 2005 (England and Wales):
  • Assume capacity; decision-specific; support the person to decide; unwise decisions don't mean incapacity.
  • Test — is there an impairment of mind or brain? Can they understand, retain, use and weigh the information, and communicate a decision?
  • Best interests — consider the patient's past and present wishes, beliefs and values; consult family, carers and anyone named; least restrictive option.
  • Advance decision to refuse treatment (ADRT) — legally binding if valid and applicable (life-sustaining treatment refusals must be written, signed and witnessed, with "even if my life is at risk").
  • Lasting power of attorney (health and welfare) — can consent to or refuse treatment on the patient's behalf (life-sustaining treatment only if expressly authorised).
  • IMCA (independent mental capacity advocate) — for serious medical decisions when there is no one appropriate to consult.
  • Scotland — Adults with Incapacity (Scotland) Act 2000; Northern Ireland — Mental Capacity Act (NI) 2016.
• DNACPR decisions — a clinical decision when CPR wouldn't work or wouldn't be in the patient's best interests; must be discussed with the patient (or family if lacking capacity) unless this would cause physical or psychological harm (Tracey judgment 2014); ReSPECT forms record broader recommendations; DNACPR doesn't mean "do not treat".
• Disagreements — communication, second opinions, mediation, clinical ethics committee, and as a last resort the Court of Protection (adults) or High Court (children).
• Children — parents with parental responsibility decide in the child's best interests; Gillick-competent young people; courts decide disputed cases.

Withdrawal of Treatment and End-of-life Care

• About 15–20% of ICU patients die — most after a decision to withdraw or limit life-sustaining treatment.
• Making the decision — consultant-led, multidisciplinary, based on the patient's prognosis and best interests; communicated honestly and compassionately with the family; documented; allow time (family may need more than one meeting).
• Moving to comfort care:
  • Stop treatments that don't add comfort — vasopressors, RRT, blood tests, observations, antibiotics, feeding (discuss).
  • Extubation (terminal extubation) or withdrawal of ventilation to a T-piece — prepare the family; anticipate secretions and breathlessness.
  • Symptom control — opioids (morphine or alfentanil) for pain and breathlessness, midazolam for distress, anticholinergics (glycopyrronium, hyoscine butylbromide) for secretions — titrated to symptoms (doctrine of double effect — the intention is comfort, not hastening death).
  • Stop neuromuscular blockers before withdrawal (so distress can be seen).
  • Privacy, family presence, spiritual and cultural needs, chaplaincy; deactivate ICDs.
• After death — verification of death, offer bereavement support, Medical Examiner review (statutory in England and Wales from September 2024), referral to the coroner (procurator fiscal in Scotland) when required — unnatural deaths, deaths after surgery or anaesthesia where these may have contributed, unknown cause, deaths in state detention (since 2017, a DoLS authorisation alone no longer counts as state detention), industrial disease.
• Euthanasia and assisted dying — illegal in the UK at present (the Terminally Ill Adults (End of Life) Bill for England and Wales was progressing through Parliament in 2025) — check the current law.

Death by Neurological Criteria

• Death — "the irreversible loss of the capacity for consciousness combined with the irreversible loss of the capacity to breathe" (AoMRC Code of Practice 2008; updated 2025) — confirmed by circulatory criteria or neurological (brain stem) criteria.
• Preconditions (all must be met):
  • An identifiable cause of irreversible brain damage (e.g. TBI, SAH, hypoxic brain injury).
  • Unresponsive coma on a ventilator (apnoeic).
  • Exclusion of reversible causes — sedatives and neuromuscular blockers (time, levels, nerve stimulator), hypothermia (core temperature over 34°C), metabolic and endocrine disturbance (sodium 115–160, potassium over 2, glucose 3–20, phosphate and magnesium 0.5–3.0), circulatory instability.
• Brain stem tests — performed by two doctors (registered over 5 years, at least one a consultant, competent, not on the transplant team), twice (time of death is the completion of the first set):
  • No pupillary response to light (CN II, III).
  • No corneal reflex (CN V, VII).
  • No oculovestibular (caloric) reflex — no eye movement with 50 mL ice-cold water in each ear (CN III, VI, VIII).
  • No motor response in the cranial nerve distribution to painful stimulus (supraorbital pressure) (CN V, VII).
  • No gag (CN IX, X) or cough reflex (suction catheter down the tracheal tube — CN X).
  • Apnoea test — preoxygenate, disconnect or CPAP; no respiratory effort with PaCO₂ rising to over 6.0 kPa and pH under 7.40 (6.5 kPa if chronic CO₂ retention).
• Spinal reflexes (limb movements, Lazarus sign) may persist and don't preclude the diagnosis.
• Ancillary tests (CT angiography, EEG) — only when the full clinical tests can't be done (e.g. severe facial injury, high cervical cord injury, drug effects).
• Physiology after brain stem death — cardiovascular instability (catecholamine storm then hypotension), diabetes insipidus, hypothermia, coagulopathy — managed if organ donation is planned.

Organ Donation

• Types of deceased donation:
  • Donation after brain stem death (DBD) — death confirmed by neurological criteria; organs retrieved with the heart beating.
  • Donation after circulatory death (DCD) — after a decision to withdraw life-sustaining treatment; death confirmed after 5 minutes of observed absent circulation; time-critical retrieval.
• The law:
  • Opt-out ("deemed consent") systems — Wales (2015), England (Max and Keira's Law, May 2020), Scotland (March 2021), Northern Ireland (June 2023) — adults are considered willing donors unless they opted out or are in an excluded group (under 18, lacking capacity for a significant period before death, not resident for 12 months).
  • Families are still consulted — the specialist nurse checks the Organ Donor Register and the patient's known wishes; donation doesn't proceed if the family provides information that the person wouldn't have wanted it.
  • Human Tissue Act 2004 (England, Wales, NI) and Human Tissue (Scotland) Act 2006.
• Best practice (NICE CG135; NHSBT):
  • Identify and refer potential donors early — refer to the specialist nurse for organ donation (SNOD) when a decision to withdraw treatment is being considered, or when brain stem death testing is planned (or GCS 4 or less without explanation).
  • Approach the family with the SNOD (higher consent rates), separately from the discussion about prognosis ("decoupling").
• Contraindications — few absolute (e.g. some active cancers, variant CJD, untreated systemic infection, HIV for most organs — though HIV-to-HIV donation occurs); age isn't a barrier — the SNOD advises.
• Donor optimisation — maintain MAP (vasopressin, noradrenaline), treat diabetes insipidus (desmopressin), hormone therapy (methylprednisolone, thyroid hormone in some), lung-protective ventilation, normothermia.
• Coroner — discuss with the coroner before donation if the death must be referred.

Communication with Families

• Families of ICU patients experience high rates of anxiety, depression and PTSD (post-intensive care syndrome — family).
• Good practice:
  • Early and regular meetings in a private room, with the nurse present; consultant-led for major decisions.
  • Prepare — know the facts, agree the message with the team, find out what the family already know.
  • Use plain language; avoid jargon ("the kidneys have stopped working" rather than "AKI stage 3"); warning shot; pause and allow silence.
  • Explore the patient's values — "What would he say if he could see himself now?" — the family's role is to tell you what the patient would want, not to make the decision.
  • Be honest about uncertainty; avoid false hope or false certainty; "hope for the best, prepare for the worst".
  • Document what was said and who was present.
• Breaking bad news — SPIKES — Setting, Perception, Invitation, Knowledge, Emotions (respond with empathy), Strategy and summary.
• Open visiting, ICU diaries (written by staff and family — help patients fill memory gaps and reduce PTSD), interpreters (not family members) when needed.
• Duty of candour — be open with patients and families when something has gone wrong (statutory duty — notifiable safety incidents).

Post-intensive Care Syndrome and Rehabilitation

• Post-intensive care syndrome (PICS) — new or worse impairments after critical illness:
  • Physical — ICU-acquired weakness, fatigue, breathlessness, reduced exercise capacity, joint stiffness, swallowing and voice problems (after intubation or tracheostomy), weight loss, hair loss, sexual dysfunction.
  • Cognitive — memory, attention and executive function problems (in up to a third — similar to mild dementia or moderate TBI in some).
  • Psychological — anxiety, depression, PTSD (often linked to delusional memories of ICU — nightmares, hallucinations).
• Impact — many survivors haven't returned to work at 1 year; financial and carer burden; families also affected (PICS-F).
• Rehabilitation (NICE CG83 and QS158):
  • During ICU — early mobilisation, physiotherapy, nutrition, minimise sedation, delirium prevention, ICU diaries, swallow assessment.
  • Before discharge from ICU — short clinical assessment for rehabilitation needs; handover to ward.
  • On the ward — individualised, structured rehabilitation programme; a named key worker.
  • After hospital discharge — functional reassessment at 2–3 months (ICU follow-up clinics), referral to rehabilitation, psychological support, information for GPs (NICE recommends discharge summaries include rehab needs).
• Peer support — ICUsteps (UK charity for patients and families).

💡 Clinical Pearl: Surviving intensive care is the start of recovery, not the end. Ask ICU survivors about nightmares, low mood, memory and fatigue — these are common, treatable, and often missed.

ICU Problems and Ethics at a Glance

Spot the Diagnosis

Exam-style Scenarios

1. A 25-year-old man with a severe TBI is ventilated with an ICP bolt. ICP is 28 mmHg, MAP 80 mmHg. PaCO₂ is 5.8 kPa, temperature 38.4°C, sodium 136.
Answer: Raised ICP with inadequate CPP (80 – 28 = 52 mmHg).

• Head up 30°, neutral neck, loosen tube ties; deepen sedation and analgesia.
• Target PaCO₂ 4.5–5.0 kPa; treat fever (normothermia); raise MAP with noradrenaline to achieve CPP 60–70.
• Osmotherapy (mannitol or hypertonic saline — also raises sodium); CT to exclude a surgical lesion; neurosurgical review (EVD, craniectomy if refractory).

2. A 70-year-old woman has been ventilated for 3 weeks after a large stroke with no improvement. Her daughter says her mother told her she would never want to be "kept alive on machines". There is no written advance decision.
Answer: Best interests decision about withdrawal of life-sustaining treatment (Mental Capacity Act 2005).