Intensive Care Medicine Flashcards
What is the nurse to px ratio on ICU compared to a normal ward?
1: 1
1: 10
How many levels of care are there in hospitals?
3 (0-4)
Describe px criteria for:
- Level 0
- Level 1
- Level 2
- Level 3
- 0 = needs can be met through normal ward care e.g. obs every 4 hours.
- 1 = risk of deterioration OR discharged from higher level - input advice from critical care outreach support team.
- 2 = pre-operative optimisation OR extended post-operative care (e.g. after major surgery) OR stepped down from higher level - receive single organ support.
- 3 = required advanced respiratory support OR 2+ organ support.
Typically level 2 and level 3 correlate to which ward in the hospital?
2 = HDU (High dependancy unit) 3 = ICU (Intensive care unit)
What px physiological variables are displayed on a monitor in ICU?
- ECG
- SpO2
- RR
- MAP (mean arterial pressure)
- CVP (central venous pressure)
Which airway devices provide a definitive airway?
- Endotracheal tube
2. Tracheostomy
Where should an ETT sit - if in the right place?
In the trachea above the carina.
Is an intubated px able to speak?
No - no airflow over the vocal cords.
What are the early complications of an ETT?
Trauma to any section of the airway (on insertion), aspiration of stomach contents, tube malposition, airway obstruction, hypoxia from prolonged attempts.
What are the late complications of an ETT?
Infection, mucosal damage to mouth or trachea due to cuff pressure, injury to vocal cords, tracheal stenosis.
What is a tracheostomy tube and for which px’s is it used?
A percutaneous airway device used for px requiring prolonged airway or ventilatory support.
Where is a tracheostomy inserted?
Through an incision in the anterior neck between the tracheal cartilaginous rings.
What are the early complications of a trachy?
Haemorrhage, pneumothorax, tube misplacement, surgical emphysema, blockage with secretions, stomal infection, TOF
What are the late complications of a trachy?
Late haemorrhage due to erosion into an artery, tracheal granulomata, tracheal stenosis, scarring, tracheal necrosis.
What is oxygenation?
The provision of oxygen to the tissues.
What is ventilation?
The delivery of oxygen to the lungs and the removal of carbon dioxide.
What is the benefit of o2 therapy?
Increased inspired o2 concentration allows better o2 delivery to the tissues.
What is the risk of o2 therapy?
High conc. inspired o2 for a long period of time (>60% for >48 hours) = pulmonary injury.
What are the two common techniques of oxygen therapy?
- Continuous positive airway pressure (CPAP)
2. Non-invasive ventilation (NIV)
When is CPAP used?
In px in acute hypoxic respiratory failure OR when weaning from invasive ventilation.
How does NIV work?
Provides a constant pressure during inspiration and expiration = incorporates CPAP + increased pressure triggered by px breathing.
This assists px’s own breathing, reducing the amount they have to ‘work’ and helping px to ‘blow off’ co2.
What type of px can NIV be used on and what is their criteria?
Alert and co-operative px. Must be able to cough, make own respiratory effort and protect airway.
Describe what happens during normal breathing - with regards to muscle contraction and expiration.
Inspiratory muscles contract = increasing thoracic volume. This creates negative pressure within the thorax= causing inflow of air. Expiration is passive.
What is IPPV and how does it work?
Intermittent positive pressure ventilation = creates positive pressure within endotracheal tube - driving air into the lungs.
What is the main advantage of IPPV?
Oxygenation and ventilation can be achieved without the patient making any respiratory effort.
What are the complications of IPPV?
Ventilator associated pneumonia (VAP) = common, ventilatory associated lung injury, pneumothorax, haemodynamic instability
What pathologies may contribute to hypotension?
Sepsis, hypovolaemia, cardiac dysfunction, anaphylaxis.
What can be given to px on ICU to support circulation?
Fluids
What must be ensured before a px is started on vasoactive drugs?
That the px is adequately fluid resuscitated.
What are the 3 types of vasoactive drugs and what do they do?
- Inotropes = increase force of contraction which increases stroke volume.
- Chronotropes = increase the heart rate.
- Vasopressors = cause vasoconstriction this increasing systemic vascular resistance.
How should vasoactive drugs be administered?
Through a central vein, via a continuous infusion.
Why should vasoactive drugs not be given through a peripheral vein?
Because of the risk of tissue ischaemia secondary to extravasation.
What receptors are affected by Adrenaline and what type of vasoactive drug is it?
- Alpha-1, beta-1 and beta-2
2. Inotrope, chronotrope and vasopressor.
What receptors are affected by Dobutamine and what type of vasoactive drug is it?
- Beta-1 and beta-2
2. Inotrope and chronotope
What receptors are affected by Noradrenaline and what type of vasoactive drug is it?
- Alpha-1 and beta-1
2. Inotrope and vasopressor
What receptors are affected by Phenylephrine and what type of vasoactive drug is it?
- Alpha-1
2. Vasopressor
Which drug does not increase vascular tone?
Dobutamine - not a vasopressor.
What is commonly a secondary effect of shock or sepsis?
AKI
How is AKI defined?
Falling urine output to less than 0.5ml/kg/hour OR acute deterioration of GFR (manifested by rising serum creatinine and urea).
What complications can untreated AKI cause?
Hyperkalaemia, acidosis, fluid overload and uraemia.
Is intermittent haemodialysis or continuous renal replacement therapy preferred on ICU and why?
Continuous renal replacement thereapy = px on ICU are less able to tolerate the large fluid changes associated with intermitted dialysis. In continuous - fluid and electrolyte changes occur continuously at a slow rate.
What is the most commonly used technique used to treat px with AKI in ICU?
Continuous veno-venous haemofiltration - large double lumen catheter inserted into central vein.
What percentage of normal px requiring renal replacement therapy for AKI will require long-term renal replacement therapy?
5-10%
Why is sedation given on ICU?
To aid tolerance of ETT, reduce px pain and anxiety, facilitate ventilation.
Typically what sedative is given on ICU?
An infusion of synthetic OPIOID (alfentanil or remifentanil) and SEDATIVE (propofol).
What are the consequences of insufficient sedation?
Chest infection, neuropathies, VTE
What is a “sedation hold”?
Should occur at least once a day - all sedation is stopped to prevent accumulation of sedative drugs, allowing assessment of neurological function and reducing risk of complications.
Why is sedation sometimes stopped after a tracheostomy?
To allow physiotherapy, interaction with clinical staff and visitors - resume ADL.
