Intensive Care Unit

• Specialised hospital wards


  • High dependency unit (HDU)
  • Intensive care unit (ICU)
• Level 1 patients can be managed on a general acute ward
• Level 2 patients can be managed on the high dependency unit
• Level 3 patients can be managed on the intensive care unit (the highest level of support)
• ICUs are run by intensive care specialists and specialist intensive care nurses
• Each nurse in the ICU only cares for one or two patients at a time
• Patients admitted to the ICU usually have some form of organ failure, requiring organ support and intensive monitoring
• Common reasons patients are admitted to intensive care

  • Following major surgery (e.g., aortic aneurysm repair)
  • Severe sepsis
  • Major trauma
  • Following cardiopulmonary resuscitation
  • Organ failure (acute respiratory, renal or liver failure)
• Advanced organ support in the ICU includes

  1. Respiratory support

  2. Cardiovascular support

  3. Renal support

  4. Nutritional support

  5. Neurological support

  6. Dermatological support

  7. Liver support
• Admission to the ICU is the decision of the intensive care specialists
• The capacity of intensive care units is often low, and the impact of intensive therapy on patients is very high
• Factors considered for ICU admission are the potential to reverse the acute condition and the baseline physiological reserve
• In patients with a high probability of dying from their current illness and an underlying terminal condition, a palliative care approach may be more appropriate than ICU admission
• There are scoring systems that are used to assess the severity of illness and predict outcomes in ICU patients
• For patients with a 90% probability of dying from their current illness and an underlying terminal condition, it does not make sense to admit them for extensive invasive interventions. A palliative care approach on a general ward or at home would be much more appropriate.
• Scoring systems to predict mortality at the time of admission to ICU

  • APACHE (Acute Physiology and Chronic Health Evaluation)
  • SAPS (Simplified Acute Physiology Score)
  • MPM (Mortality Prediction Model)
• Nutrition in critically ill patients

  • They are in a hypermetabolic state and have increased nutritional requirements
  • There is a high risk of malnutrition, which can contribute to worse outcomes
• Dieticians


  Involved in helping ensure patients meet their nutritional requirements
• Enteral nutrition


  1. Mouth

  2. NG tube

  3. Percutaneous endoscopic gastrostomy (PEG)
• Total parenteral nutrition (TPN)


  1. Intravenous infusion of a solution of carbohydrates, fats, proteins, vitamins, and minerals to meet the complete nutritional requirements of the patient

  2. Prescribed under the guidance of a dietician

  3. TPN is very irritant to veins and can cause thrombophlebitis, so it is normally given through a central line rather than a peripheral cannula
• Complications associated with admission and treatment on ICU

  • Ventilator-associated lung injury
  • Ventilator-associated pneumonia
  • Catheter-related bloodstream infections (e.g., from central venous catheters)
  • Catheter-associated urinary tract infections
  • Stress-related mucosal disease
  • Delirium
  • Venous thromboembolism
  • Critical illness myopathy
  • Critical illness neuropathy
• Ventilator-associated lung injury


  • Common complication of mechanical ventilation
  • Can cause volutrauma, barotrauma, and inflammation
  • Can lead to short-term pulmonary oedema and hypoxia, and long-term fibrosis of lung tissue, reduced lung function, recurrent infections, and cor-pulmonale
• Ventilator-associated pneumonia


  • Common complication of mechanical ventilation
  • Up to 25% risk and carries a high risk of death
  • Risk can be reduced by positioning the bed at a 30-degree angle with the patient’s head elevated and good oral care
• Catheter-related bloodstream infections


  • Common complication introduced by invasive lines
  • Up to 25% risk and carries a high risk of death
  • Risk may be reduced by using antibiotic-impregnated or silver-impregnated catheters and keeping them in for the shortest time possible
• Catheter-associated urinary tract infections


  • Common complication
  • Risk can be reduced by only using urinary catheters when necessary and keeping them in for the shortest time possible
• Stress-related mucosal disease


  • Common in critically unwell patients
  • Damage to the stomach mucosa mainly due to impaired blood flow
  • Increases the risk of upper gastrointestinal bleeding, which can be life-threatening
• Causes of stress-related mucosal disease

  • Impaired blood flow
• Impaired blood flow


  Mainly causes damage to the stomach mucosa
• Damage to the stomach mucosa

  Increases the risk of upper gastrointestinal bleeding
• Increased risk of upper gastrointestinal bleeding


  Can be life-threatening
• Ways to reduce the risk of upper gastrointestinal bleeding

  • Suppressing acid secretion in the stomach using proton pump inhibitors (e.g., omeprazole)
  • Suppressing acid secretion in the stomach using H2 receptor antagonists (e.g., ranitidine)
  • Starting NG feeding early in patients that cannot eat normally
• Trophic feeds


  Small volumes used for gastrointestinal benefits but are insufficient to meet nutritional requirements
• Delirium is a very common complication of critical illness and intensive care
• Causes of acute confusion

  • Pain
  • Infection
  • Hypoxia
  • Electrolyte disturbances
  • Renal failure
  • Medications
• Patients in ICU will often have many causes of acute confusion occurring simultaneously
• Using the Confusion Assessment Method (CAM)


  As a scoring system for identifying delirium
• Dexmedetomidine is a medication used in the intensive care unit to sedate agitated patients
• Components of Venous thromboembolism (VTE)

  • Deep vein thrombosis
  • Pulmonary embolism
• Critically ill patients are at higher risk of VTE
• Every patient in ICU will have a risk assessment to determine if they require prophylaxis for VTE