GC005 The Patient Is Critically Ill - Intensive Care Medicine; Unstable Vital Organ Function
Unstable vital organ function refers to the acute failure or impending failure of one or more vital organ systems—such as cardiovascular, respiratory, neurological, or renal—requiring immediate monitoring and intervention in an intensive care setting to prevent irreversible damage or death.
This lecture, delivered by Dr. WM Chan from the Adult ICU at Queen Mary Hospital, is foundational for understanding what happens when a patient is so sick that ordinary ward-level care is no longer enough. It is the first building block of critical care medicine in the General Clerkship and directly feeds into GC 006 (post-operative management), GC 222 (organ donation), and the Block C Critical Care Medicine tutorial. The examiners love this lecture because it tests conceptual understanding — why we admit patients to ICU, how we support failing organs, when we say "enough," and the ethical framework around those decisions.
Learning Objectives (from the lecture and GCBC outline)
- Define what an ICU is and why it exists.
- Understand ICU staffing, nursing ratios, and functional considerations.
- Describe the types of monitoring available in ICU (basic → invasive → advanced).
- Explain the concept of organ failure and organ support — the three goals of ICU organ support.
- Understand ICU triage: reversibility, quality of life, disease severity.
- Recognize the grey zone in triage and the limitations of prognostication.
- Appreciate the pros and cons of ICU admission.
- Understand long-term outcomes of ICU survivors (AKI example).
- Apply ethical principles to DNACPR decisions.
- Appreciate that ICU outcome is more than just mortality.
An Intensive Care Unit (ICU) is a specially staffed and equipped, separate and self-contained area of a hospital dedicated to the management of patients with life-threatening illnesses, injuries and complications, and monitoring of potentially life-threatening conditions. It provides special expertise and facilities for support of vital functions and uses the skills of medical, nursing and other personnel experienced in the management of these problems. [1]
This definition comes from the College of Intensive Care Medicine of Australia and New Zealand (2011) and is the exam definition. Let's unpack why every word matters:
- "Specially staffed and equipped" — ICU is not just a ward with more beds. It requires dedicated staff with specific training and equipment (ventilators, ECMO, infusion pumps, invasive monitors) that regular wards simply do not have.
- "Separate and self-contained" — ICU operates as its own unit with its own protocols, infection control, and governance. This is important because critically ill patients are immunocompromised and vulnerable to nosocomial multi-resistant organisms.
- "Life-threatening illnesses, injuries, and complications" — This defines the patient population. You don't admit someone to ICU for observation of mild conditions. The threshold is life-threatening.
- "Monitoring of potentially life-threatening conditions" — Not all ICU patients have active organ failure. Some are there because their condition could deteriorate rapidly (e.g., post-major surgery, massive PE on anticoagulation).
- "Support of vital functions" — This is the crux. The ICU exists to keep vital organs going while the underlying disease is treated or resolves.
Exam Framing
If asked "What is an ICU?", quote this definition. Examiners expect the CICM-ANZ definition because it is on the lecture slide. Hit the key phrases: specially staffed, equipped, self-contained, life-threatening, support of vital functions.
2. ICU Staffing
Patients staying in ICU require a high intensity of nursing care. A nurse to patient ratio of 1:1 for ventilated patients, 1:2 for lower acuity. Majority should have post-registration qualification in Intensive Care. Competent to provide advanced life support. [1]
Why 1:1 nursing? A ventilated patient cannot call for help, cannot reposition themselves, and any small change (e.g., kinking of the endotracheal tube, disconnection of a line, sudden arrhythmia) requires immediate recognition and action. One nurse per patient ensures continuous surveillance. Lower-acuity patients (e.g., those being weaned from ventilation or on non-invasive monitoring) can tolerate 1:2 ratios because they are more stable and can signal distress.
Why post-registration ICU qualification? ICU nurses manage vasopressor infusions, interpret waveforms, troubleshoot ventilator alarms, and perform interventions that ward nurses are not trained for. They are also expected to be competent in advanced life support (ALS) — meaning they can initiate resuscitation immediately if a patient arrests.
Headed by a full-time Medical Director. Sufficient specialist staff with experience in intensive care medicine. In HK, specially trained doctors — Anaesthesiologists or Physicians by training background. Preferably full time. [1]
Why does training background matter? In Hong Kong, intensivists come from two backgrounds:
- Anaesthesiology: strong in airway management, ventilator settings, sedation, pain management
- Internal Medicine (Physician): strong in managing the medical diseases that land patients in ICU (sepsis, ARDS, AKI, etc.)
Both backgrounds converge into the specialty of Intensive Care Medicine. The emphasis on "preferably full time" means that ICU should not be a moonlighting job — the complexity of patients demands dedicated attention.
3. Functional Considerations of the ICU
The ICU is set up to provide: (1) Intensive Therapy and Organ Support, (2) Intensive Monitoring, (3) Possibly: Organ Support for Potential Organ Donors. [1]
This is the primary reason the ICU exists. When an organ fails, the ICU provides temporary replacement or support so the organ can recover. Examples:
| Failing Organ | ICU Support | How It Works |
|---|---|---|
| Lungs | Mechanical ventilation (invasive/non-invasive), ECMO | Takes over the work of breathing and gas exchange |
| Heart/Circulation | Vasopressors, inotropes, IABP, VA-ECMO | Maintains cardiac output and blood pressure |
| Kidneys | Continuous renal replacement therapy (CRRT), intermittent haemodialysis | Removes waste and manages fluid/electrolytes |
| Brain | ICP monitoring, osmotherapy, targeted temperature management | Prevents secondary brain injury |
| Liver | Supportive care, molecular adsorbent recirculating system (MARS) (rare) | Buys time for transplant or recovery |
| Coagulation | Blood product transfusion, factor replacement | Corrects coagulopathy |
One of the major duties of an ICU is to support failing organs aiming at: (1) Salvage important organ function before irreversible damage, (2) Buy time for eventual organ recovery, (3) Provide definitive treatment if possible to enhance recovery. [1]
High Yield – Three Goals of ICU Organ Support
1. Salvage organ function before irreversible damage — e.g., early dialysis in severe AKI to prevent uraemic complications.
2. Buy time for eventual organ recovery — e.g., mechanical ventilation in ARDS while the lung inflammation resolves over days to weeks.
3. Provide definitive treatment if possible to enhance recovery — e.g., percutaneous coronary intervention for STEMI causing cardiogenic shock.
These three goals are testable. They distinguish ICU from palliation: ICU organ support is a bridge, not a destination.
More comprehensive monitoring: Central Venous Pressure, ECG, urine output. Invasive Artery Blood Pressure monitoring. Other monitoring: Cardiac output measurements. [1]
Why do we need all this? Because critically ill patients change minute to minute. A standard ward observation chart (vital signs every 4–6 hours) would miss a rapid deterioration. ICU monitoring is continuous and invasive where needed.
| Type of Monitoring | What It Measures | Why It Matters |
|---|---|---|
| ECG (continuous) | Heart rate, rhythm, ST changes | Detects arrhythmias, ischaemia in real time |
| Pulse oximetry (SpO₂) | Oxygen saturation | Detects hypoxaemia before cyanosis is visible |
| Invasive arterial BP (via radial arterial catheter) | Beat-to-beat blood pressure, arterial waveform | More accurate than NIBP in shocked patients; allows frequent ABG sampling [1] |
| Central Venous Pressure (CVP) | Right atrial pressure (proxy for preload) | Guides fluid management in shock |
| Urine output (via Foley catheter) | Hourly urine output | End-organ perfusion marker; target ≥ 0.5 mL/kg/hr |
| Cardiac output monitoring | CO, CI, SVR | Differentiates types of shock; guides vasopressor/inotrope titration |
The radial arterial catheter is specifically shown and highlighted in the lecture slides. It is inserted into the radial artery (Allen's test first to confirm dual arterial supply to the hand), transduced to give a continuous arterial waveform, and allows frequent arterial blood gas sampling without repeated needle sticks.
Possibly: Organ support for potential organ donors. [1]
This is a unique ICU function. When brain death is declared, the ICU continues to support the body's organs not for the patient's benefit (they are dead), but to preserve organ viability for transplantation. This connects directly to GC 222 (organ donation), where loss of brainstem function results in haemodynamic instability, hypothermia, cranial diabetes insipidus, and electrolyte disturbances — all of which the ICU team must manage to keep organs transplantable. [2]
The lecture slide shows a photograph of a real ICU bedspace with labelled equipment [1]:
| Equipment | Purpose |
|---|---|
| Ventilator | Provides mechanical ventilation |
| Monitor | Displays continuous vital signs (ECG, SpO₂, invasive BP, CVP, etc.) |
| Infusion pumps | Delivers precise drug infusions (vasopressors, sedation, analgesia, antibiotics) |
| Heating device | Maintains normothermia (hypothermia → coagulopathy, arrhythmia, impaired immunity) |
| Extracorporeal Membrane Oxygenator (ECMO) | Provides extracorporeal gas exchange (and sometimes circulatory support in VA-ECMO) |
ECMO deserves special mention. It is essentially an artificial lung (and heart, in VA mode) outside the body. Blood is drained from the patient, passed through an oxygenator membrane, and returned. Types:
- VV-ECMO (veno-venous): for isolated respiratory failure (e.g., severe ARDS). Blood drained from a large vein, oxygenated, returned to a large vein. Heart still pumps.
- VA-ECMO (veno-arterial): for combined cardiac and respiratory failure (e.g., cardiogenic shock, cardiac arrest). Blood drained from a vein, oxygenated, and returned to an artery, bypassing both heart and lungs. [3]
When the ICU Team was called — Diagnosis: Septic Shock, Peritonitis. What are the considerations as to whether you will take Madam ABC? [1]
This is a clinical scenario used to illustrate the triage process. A patient with peritonitis (likely bowel perforation or similar surgical emergency) has developed septic shock (sepsis with circulatory failure). The question "will you take her?" forces you to think about triage.
Understanding Septic Shock (Sepsis-3, 2016)
Before discussing triage, let's define the terms:
- Sepsis: Life-threatening organ dysfunction caused by a dysregulated host response to infection. Operationally, organ dysfunction = increase in SOFA score ≥ 2 points. [4]
- Septic shock: A subset of sepsis with profound circulatory, cellular, and metabolic abnormalities. Clinically identified by:
- Need for vasopressors to maintain MAP ≥ 65 mmHg
- Serum lactate > 2 mmol/L despite adequate volume resuscitation
- Mortality > 40% [4]
SIRS vs Sepsis-3
The old SIRS criteria (Temp + HR + RR + WBC) are no longer used to define sepsis since 2016. SIRS is too sensitive and non-specific — many hospitalized patients meet SIRS criteria without infection. The current definition centres on organ dysfunction (SOFA score), not just inflammation. However, SIRS criteria are still useful as a screening tool to prompt further evaluation. Know both for exams, but default to Sepsis-3 framing. [4][5]
SOFA Score Components (testable — appears in GC 005 context and multiple senior notes):
| System | Parameter |
|---|---|
| Respiratory | PaO₂/FiO₂ ratio |
| Cardiovascular | MAP or vasopressor dose required |
| Hepatic | Bilirubin |
| Renal | Creatinine or urine output |
| Neurological | GCS |
| Coagulation | Platelet count |
A SOFA increase ≥ 2 is associated with mortality ≥ 10%. [4]
qSOFA (quick SOFA) — for out-of-ICU bedside screening:
- RR ≥ 22/min
- SBP ≤ 100 mmHg
- Altered mental status (GCS < 15)
- Score ≥ 2 suggests worse outcome; prompts further investigation for sepsis. [4]
6. The Process of Triage
Triage is: the process of selection of patients for admission to the ICU. One of the key functions of an ICU. Three criteria to consider: (1) Reversibility, (2) Quality of Life, (3) Disease Severity. [1]
High Yield – Three Triage Criteria for ICU Admission
1. Reversibility — Is the underlying condition potentially reversible with ICU-level intervention? If the disease process is terminal and no treatment can change the trajectory, ICU admission may only prolong suffering.
2. Quality of Life — What will the patient's functional status be if they survive? This considers pre-morbid function, patient wishes, and likely post-ICU disability.
3. Disease Severity — The patient must be sick enough to benefit from ICU but not so sick that ICU care would be futile.
Severity of Disease: Too Well To Need ICU Care ← Mild — Moderate — Severe — Very Severe → Too Ill To Benefit from ICU Care. Admitted patients fall in the middle range. [1]
Think of this as a bell curve or spectrum. The ICU admits patients in the middle zone where the illness is severe enough that ward-level care would be inadequate, but not so overwhelming that death is inevitable despite all interventions.
| Zone | Description | Appropriate Action |
|---|---|---|
| Too well | Stable vital signs, no organ failure, can be managed on ward | Ward or HDU care |
| Moderate–Severe | One or more organ failures that are potentially reversible | ICU admission |
| Too ill / Irreversible | Terminal disease, irreversible multi-organ failure, brain death | Palliative care, comfort measures |
Can we precisely tell the severity? And reversibility? Problem: There is a grey zone on either side. [1]
This is a critically important exam concept. In reality, we cannot perfectly predict who will benefit from ICU and who won't. The grey zone exists because:
- Prognostic uncertainty — Scoring systems (APACHE, SOFA) give probabilities, not certainties. A patient with a 90% predicted mortality still has a 10% chance of survival.
- Individual variation — Two patients with identical diagnoses and severity scores may have vastly different outcomes based on genetics, physiological reserve, and response to treatment.
- Dynamic nature of disease — A patient who looks "too ill" on day 1 may improve dramatically with 48 hours of ICU support, and vice versa.
This means triage is never a simple algorithm — it requires clinical judgment, experience, and repeated reassessment. When in doubt, a trial of ICU therapy with clear goals and reassessment timelines is often appropriate.
Pros: More Intensive Therapy & Monitor; Maybe the only means to save a life. Cons: Invasive Procedures; Infection Risks (Multi-resistant Organisms); Loss of Self-Esteem; Other Sequels. [1]
This is not just a slide to memorize — it drives real clinical decision-making.
| Pros | Why It Matters |
|---|---|
| More intensive therapy and monitoring | Organ support + continuous surveillance can detect and treat deterioration early |
| May be the only means to save a life | Some conditions (e.g., fulminant sepsis, respiratory failure needing ventilation) simply cannot be managed on a ward |
| Cons | Why It Matters |
|---|---|
| Invasive procedures | Arterial lines, central lines, intubation, chest drains — each carries risk of bleeding, infection, pneumothorax |
| Infection risks (multi-resistant organisms) | ICU patients are immunocompromised, have multiple portals of entry (lines, catheters), and are exposed to resistant organisms like MRSA, VRE, MDR Gram-negatives |
| Loss of self-esteem | Patients are often naked, sedated, unable to communicate, dependent on machines for basic functions — this is profoundly distressing and can cause lasting psychological harm |
| Other sequels | Post-intensive care syndrome (PICS): cognitive impairment, PTSD, depression, physical debility, chronic pain, ICU-acquired weakness — affects up to 50% of ICU survivors |
Post-ICU Morbidity
The lecture explicitly warns that ICU admission is not "free." The concept of PICS (Post-Intensive Care Syndrome) — a triad of physical, cognitive, and psychological impairment after critical illness — is increasingly tested. Even if a patient survives, the quality of that survival matters enormously.
Wald JAMA 2009: Adult patients with AKI in ICU — AKI (N=3769) vs No AKI (N=13598). Median follow-up 3 years. AKI group: 8.5% progressed to chronic dialysis (HR 3.23 compared to no-AKI group). Mortality was similar between groups. [1]
This data is on the slide with Kaplan-Meier curves and a data table. The key teaching points:
- AKI in ICU is not just a transient problem — even patients who "recover" renal function in ICU have a 3.2x higher risk of eventually needing chronic dialysis compared to ICU patients without AKI.
- Mortality was similar between AKI and non-AKI groups (~35% at 3 years), which means AKI survivors don't die more, but they accumulate significant morbidity (CKD, dialysis dependency).
- This reinforces the "cons" of ICU — organ support can save your life but may leave lasting damage.
From first principles: AKI causes tubular necrosis. Even if GFR recovers, there is residual nephron loss and fibrosis. Over time, remaining nephrons undergo hyperfiltration, leading to progressive CKD. This is the pathophysiological basis for the Wald JAMA 2009 finding. [1][6]
Risk of Chronic Dialysis After ICU AKI
AKI in ICU → adjusted HR 3.23 (95% CI 2.70–3.86) for chronic dialysis — this means even "recovered" AKI patients need long-term renal follow-up. This is a commonly tested fact linking ICU medicine to nephrology.
9. Organ Failures in the ICU — A Systems Approach
Although the lecture focuses on the philosophy and structure of ICU care, the clinical reality is that ICU patients have organ failures. Here is a comprehensive systems-based approach to organ support, integrating the lecture with supporting material:
Types:
- Type 1 (Hypoxaemic): PaO₂ < 8 kPa (60 mmHg) with normal or low PaCO₂. Caused by V/Q mismatch or shunt (e.g., pneumonia, ARDS, PE).
- Type 2 (Hypercapnic): PaCO₂ > 6.7 kPa (50 mmHg) with low pH. Caused by ventilatory failure (e.g., COPD exacerbation, neuromuscular disease, drug overdose).
ICU Respiratory Support:
| Modality | Indication | Mechanism |
|---|---|---|
| Supplemental O₂ | Mild hypoxaemia | Increases FiO₂ |
| HFNC (High-Flow Nasal Cannula) | Moderate hypoxaemia, comfort | Delivers heated humidified O₂ at high flow; generates small PEEP |
| NIV (CPAP/BiPAP) | Type 2 failure (COPD), acute pulmonary oedema | CPAP: continuous positive pressure keeps alveoli open. BiPAP: also assists inspiration |
| Invasive mechanical ventilation | Severe respiratory failure, GCS < 8, apnoea, haemodynamic instability | Full control of ventilation through endotracheal tube |
| ECMO (VV) | Refractory ARDS, bridge to lung transplant | Extracorporeal oxygenation bypassing damaged lungs |
ARDS (Acute Respiratory Distress Syndrome) is the archetypal ICU respiratory problem:
- Berlin Definition (2012): Acute onset, bilateral opacities on CXR not fully explained by effusions/atelectasis, respiratory failure not fully explained by cardiac failure, PaO₂/FiO₂ ratio < 300 on PEEP ≥ 5 cmH₂O.
- Severity: Mild (PaO₂/FiO₂ 200–300), Moderate (100–200), Severe ( < 100).
- Management: Lung-protective ventilation (low tidal volume 6 mL/kg ideal body weight, plateau pressure < 30 cmH₂O), prone positioning, conservative fluid strategy, neuromuscular blockade in severe cases, ECMO as rescue. [7]
The lecture case involves septic shock. Understanding the four types of shock is essential:
| Type | Mechanism | Examples | Haemodynamic Profile |
|---|---|---|---|
| Hypovolaemic | ↓ Preload from volume loss | Haemorrhage, dehydration, burns | ↓CO, ↑SVR, ↓CVP |
| Cardiogenic | ↓ Pump function | MI, ADHF, arrhythmia, myocarditis | ↓CO, ↑SVR, ↑CVP |
| Distributive | ↓ SVR from vasodilation | Sepsis, anaphylaxis, neurogenic | ↑CO (early), ↓SVR, ↓CVP (initially) |
| Obstructive | Mechanical obstruction to flow | PE, tamponade, tension PTX | ↓CO, ↑SVR, ↑CVP |
Management Principles (Septic Shock — integrating Sepsis-3 and Surviving Sepsis Campaign):
- Hour-1 Bundle: Measure lactate, obtain blood cultures before antibiotics, administer broad-spectrum antibiotics, begin rapid 30 mL/kg crystalloid for hypotension/lactate ≥ 4, start vasopressors (noradrenaline first-line) if MAP < 65 mmHg during or after fluid resuscitation.
- Source control: The lecture case is peritonitis — this needs surgery (laparotomy, drainage, repair). No amount of ICU support will work if the source is not controlled.
- Ongoing: Reassess fluid responsiveness, target MAP ≥ 65, serial lactate clearance, monitor end-organ perfusion (urine output, mental status).
AKI in ICU is extremely common (affects 20–50% of ICU patients). The three goals of ICU organ support apply directly:
- Salvage: Early recognition and treatment of reversible causes (pre-renal: volume resuscitation; post-renal: relieve obstruction).
- Buy time: CRRT or intermittent haemodialysis for severe AKI with refractory hyperkalaemia, acidosis, fluid overload, or uraemic complications.
- Definitive treatment: Treat the underlying cause (e.g., antibiotics for sepsis-induced AKI, immunosuppression for RPGN). [6]
- GCS monitoring: Standard in ICU. GCS < 8 → cannot protect airway → intubation.
- ICP monitoring: For traumatic brain injury, severe stroke, hepatic encephalopathy with cerebral oedema.
- Targeted temperature management: Post-cardiac arrest.
- ICU supportive care: Monitor INR, ammonia, bilirubin daily.
- NAC for both paracetamol and non-paracetamol acute liver failure. [8]
- Bridge to transplant if criteria met (King's College Criteria).
- DIC: Treat the underlying cause; replace with platelets, FFP, cryoprecipitate as needed.
- Massive transfusion protocol: 1:1:1 ratio (RBC:FFP:Platelets).
Ethical Principles in Considering Do-Not-Attempt Cardiopulmonary Resuscitation (DNACPR): Medical Futility, Principle of Patient Autonomy, Principle of Non-Maleficence, Principle of Non-abandonment, Principle of Beneficence. [1]
High Yield – Five Ethical Principles for DNACPR
1. Medical Futility — CPR will not achieve meaningful survival (e.g., terminal cancer with multi-organ failure). If CPR cannot restore a heartbeat or only restores circulation to a body that will inevitably die, it is futile.
2. Patient Autonomy — The patient (or their advance directive/legally appointed surrogate) has the right to refuse CPR. Their wishes must be respected.
3. Beneficence — Acting in the patient's best interest. If CPR would restore them to a life of suffering, it may not be beneficent.
4. Non-maleficence — "First, do no harm." CPR is violent (rib fractures, aspiration, hypoxic brain injury from prolonged arrest) — performing it when futile causes harm.
5. Non-abandonment — DNACPR does NOT mean "do not treat." It means do not attempt CPR if cardiac arrest occurs. All other treatments, comfort measures, and supportive care continue. This principle is crucial for families who fear that DNACPR = giving up.
How to apply these in the exam:
- If asked about ethics of withdrawal/withholding treatment, use these five principles as your framework.
- Key discriminator: Non-abandonment vs. futility. Families often confuse DNACPR with "doing nothing." You must explain that DNACPR is about not performing CPR specifically while continuing all other appropriate care.
ICU Outcome is not only measured by the crude mortality. It is also measured by the quality & comfort that the team provides to patients who will survive, and by the care and comfort provided to patient and family for those who eventually die. [1]
This slide encapsulates the holistic philosophy of ICU care:
- For survivors: Outcome includes functional recovery, cognitive function, return to independence, quality of life. This is why PICS awareness, rehabilitation, and follow-up clinics matter.
- For those who die: Outcome includes dignity in dying, symptom control, family support, bereavement care. A "good death" in ICU is one where the patient is comfortable, the family is informed and supported, and the medical team has communicated honestly.
- Crude mortality alone is misleading — an ICU that never admits dying patients will have low mortality but is failing its community. An ICU that provides excellent palliative care to patients who cannot survive is providing high-quality medicine.
| Related Lecture | Connection |
|---|---|
| GC 006: Post-operative management | Patients post-major surgery often need ICU. Post-op complications (bleeding, sepsis, respiratory failure) require the organ support described here. |
| GC 059: High fever, low BP | Septic shock — direct application of triage, organ support, and SOFA scoring from this lecture. |
| GC 188: Abdominal injury | Trauma patients with haemorrhagic shock need ICU for resuscitation and monitoring. FAST scan, damage control surgery, then ICU. |
| GC 222: Organ donation | ICU's third function — organ support for potential donors. Brain death management connects directly. |
| GC 208: Head injury | Neuro-ICU care, ICP monitoring, targeted management of secondary brain injury. |
| GCBC Critical Care Medicine I | Tutorial session building on this lecture with hands-on POCUS and case-based discussion. |
| GC 002: Pre-operative assessment | Assessing fitness for surgery is essentially assessing risk of needing ICU post-operatively. |
13. Likely Exam Questions
-
A 72-year-old man with metastatic pancreatic cancer develops respiratory failure. His family requests ICU admission. Which of the following is the MOST important factor in the triage decision?
- A. Age of the patient
- B. Family's wishes
- C. Reversibility of the underlying condition ✓
- D. Number of available ICU beds
- E. The patient's insurance status
- Why C: Reversibility is the primary triage criterion. Metastatic pancreatic cancer is not reversible; ICU would not change the trajectory.
-
Which of the following is NOT a component of the SOFA score?
- A. PaO₂/FiO₂ ratio
- B. Platelet count
- C. Heart rate ✓
- D. GCS
- E. Serum creatinine
- Why C: SOFA uses cardiovascular assessment by vasopressor requirement and MAP, not heart rate alone.
-
A patient with septic shock in ICU develops AKI requiring CRRT. After recovery, what is the long-term renal risk compared to ICU patients without AKI?
- A. No increased risk
- B. 1.5x increased risk of chronic dialysis
- C. 3.2x increased risk of chronic dialysis ✓
- D. 5x increased risk of chronic dialysis
- E. 10x increased risk of chronic dialysis
- Wald JAMA 2009 data from the lecture slide [1]
-
"List three goals of organ support in the ICU." (3 marks)
- Salvage important organ function before irreversible damage (1 mark)
- Buy time for eventual organ recovery (1 mark)
- Provide definitive treatment if possible to enhance recovery (1 mark)
-
"A 65-year-old woman with peritonitis is in septic shock. The ICU team is called. List three criteria you would consider in deciding whether to admit her to ICU." (3 marks)
- Reversibility of the condition (1 mark)
- Quality of life (pre-morbid function, patient wishes) (1 mark)
- Disease severity (is she sick enough to benefit but not too sick for it to be futile?) (1 mark)
-
"Name five ethical principles relevant to DNACPR decisions." (5 marks)
- Medical futility, Patient autonomy, Beneficence, Non-maleficence, Non-abandonment (1 mark each)
-
"List three risks/cons of ICU admission." (3 marks)
- Invasive procedures (1 mark)
- Infection risks including multi-resistant organisms (1 mark)
- Loss of self-esteem / psychological sequelae / PICS (1 mark)
From review of past Fourth Summative papers, critical care questions tend to focus on:
- Shock classification and management (especially septic shock) [9][10]
- Indications for ICU admission / triage
- SOFA score components
- ARDS definition and management principles
- Ethical principles in end-of-life ICU decisions
- Post-ICU complications (AKI → CKD, PICS)
| Trap | Correct Understanding |
|---|---|
| "ICU admission is always beneficial" | No — ICU carries risks (infection, PICS, invasive procedures). Triage considers whether benefit outweighs harm. |
| "DNACPR means do not treat" | DNACPR means do not attempt CPR. ALL other treatments continue. |
| "SIRS criteria define sepsis" | Since 2016 (Sepsis-3), sepsis is defined by organ dysfunction (SOFA ≥ 2 increase), not SIRS criteria. |
| "All patients with shock are hypotensive" | Early compensated shock (Stage I) has normal BP. Shock = tissue hypoperfusion, not just low BP. |
| "AKI in ICU resolves completely" | Even after apparent recovery, ICU AKI patients have 3.2x risk of chronic dialysis. |
| "ICU outcome = mortality rate" | ICU outcome also includes quality of survival and comfort provided to dying patients and families. |
| "qSOFA is used inside ICU" | qSOFA is for out-of-ICU screening. Inside ICU, use full SOFA score. |
High Yield Summary
The ICU is a specially staffed, equipped, self-contained unit for managing life-threatening conditions through intensive monitoring, organ support, and potentially supporting organ donors.
Three functions: Intensive therapy/organ support, intensive monitoring, organ support for potential donors.
Three goals of organ support: Salvage function before irreversible damage, buy time for recovery, provide definitive treatment.
Triage criteria: Reversibility, quality of life, disease severity. A grey zone exists on both sides — clinical judgment and reassessment are essential.
Pros of ICU: Intensive therapy/monitoring, may be only way to save a life. Cons: Invasive procedures, multi-resistant infections, loss of self-esteem, PICS.
AKI in ICU: HR 3.23 for chronic dialysis vs. non-AKI ICU patients (Wald JAMA 2009).
DNACPR ethics: Medical futility, patient autonomy, beneficence, non-maleficence, non-abandonment.
ICU outcome: Not just mortality — quality and comfort for survivors AND for those who die.
Sepsis-3: Sepsis = organ dysfunction (SOFA ≥ 2) due to infection. Septic shock = vasopressor requirement for MAP ≥ 65 + lactate > 2 despite fluid resuscitation. SIRS criteria are outdated for defining sepsis.
SOFA components: Respiratory (PaO₂/FiO₂), cardiovascular (vasopressor requirement), hepatic (bilirubin), renal (creatinine/UO), neurological (GCS), coagulation (platelets).
Active Recall - Intensive Care Medicine & Unstable Vital Organ Function
[1] Lecture slides: GC 005 - The patient is critically ill - Intensive care medicine; Unstable vital organ function [Updated 2025].pdf (all pages cited) [2] Lecture slides: GC 222. I want to donate my organs.pdf (pages on brainstem death physiology) [3] Senior notes: Ryan Ho Cardiology.pdf (section on ECMO and acute HF management) [4] Senior notes: Ryan Ho Critical Care.pdf (section 1.3.5 on septic shock, SOFA, qSOFA) [5] Senior notes: MBBS Final MB (Medicine) (Felix PY Lai).pdf (section on SIRS, Sepsis-3, SOFA) [6] Senior notes: Ryan Ho Critical Care.pdf (section 1.4 on AKI and renal support) [7] Senior notes: Ryan Ho Respiratory.pdf (section 2.5.2 on ARDS) [8] Senior notes: Maksim Medicine Notes.pdf (section 7.6 on acute liver failure management) [9] Past papers: 2023 Fourth Summative MCQ.pdf [10] Past papers: 2024 Fourth Summative SAQ.pdf
GC004 The Pain Is Intolerable - Pain Control
Pain control is the systematic assessment and management of acute or chronic pain using pharmacological, interventional, and non-pharmacological strategies to reduce suffering and restore function.
GC006 The Patient Is Very Ill After The Operation - Post-operative Management
Post-operative management of critically ill surgical patients involves systematic monitoring and treatment of complications such as hemorrhage, infection, respiratory failure, and organ dysfunction to ensure recovery and prevent deterioration.