Assessment of the Critically Ill Patient Flashcards
(48 cards)
Define shock
Decreased blood perfusion of tissues, inadequate blood oxygen saturation/increased oxygen demand from tissues causing decreased end-organ oxygenation and dysfunction
Outline the different types of shock
Cardiogenic - occurs when the heart fails to pump blood out e.g. cardiac output is reduced or impaired, leading to reduced blood pressure, tissue perfusion and therefore oxygen delivery.
Obstructive - occurs when the heart pumps well but the outflow is obstructed.
Low volume - occurs when there is reducing circulating blood volume leading to reduced blood pressure, therefore tissue perfusion and inadequate oxygen supply. The heart is pumping normally.
Distributive -is when the patient experiences systemic vasodilation, which leads to a drop in their systemic vascular resistance (SVR) and therefore blood pressure.
Name the causes of distributive shock
a. Anaphylaxis: The allergic response leads to mass vasodilatation and leaking of fluid from intravascular to extravascular spaces, reducing both SVR and circulating volume and therefore blood pressure.
b. Sepsis: like anaphylaxis, this causes mass vasodilatation and leaking of fluid from intravascular to extravascular spaces, reducing both SVR and circulating volume. You will learn a lot more about this in the sepsis chapter.
c. Neurogenic e.g. spinal cord injury: this is because of reduced sympathetic tone, leading to reduced SVR.
Name the causes of obstructive shock
a. Tension pneumothorax. In a tension pneumothorax a rapid increase in intrathoracic pressure compresses the mediastinum, reducing venous return (VR) and therefore cardiac output (CO).
b. Pulmonary embolism (PE). This leads to obstructive shock as the PE causes intravascular occlusion, which leads to a rapid increase in RV afterload, reducing venous return and therefore CO.
c. Cardiac tamponade - build up of fluid around the pericardium causing compression of ventricles and reducing stroke volume and CO
How do you assess a critically ill patient?
Systems approach: Respiratory CVS CNS Renal Haematological MSK
OR
A,B,C approach: A- airway B- breathing C- circulation D- disability -alertness E- exposure F- fluids - renal system G- GI H- haematological
What is the name for an artificial airway?
Where (in the body) can a patient be intubated?
When would nasal intubation be used?
Endotracheal tube (ETT) Orally or nasally Used for adults with abnormal upper airway anatomy or for infants/children as it allows the child to eat and it is allows more stable placement through the shorter trachea of the child
Name the reasons why a patient would require an artificial airway?
Route for mechanical ventilation
To secure and maintain a clear airway when patient has;
- GCS < 8
- Head/facial trauma
- Upper airway obstruction e.g. inhalation burns
Clear bronchial secretions
Protect the lungs from aspiration
Name 3 features of an ETT
- A radio-opaque strip down the side: this is so that it can be seen easily on a chest X- ray
- A tape measure strip down the side. This is so that the ICU team know that the tube is in the right position & not down too far in the right main bronchus, or up too high, above the larynx.
- A cuff – a circumferential balloon around the distal end of the ETT. Pressure of the cuff should be 20-30cmH2O. Over-inflation of the cuff leads to trauma to tracheal mucosa. Under-inflation increases risk of pneumonia.
What is the purpose of the cuff?
To prevent aspiration (chocking) of oral secretions or prevents secretions going into the lungs causing infection
To prevent a leak from positive pressure
Where should the ETT sit on a chest x-ray?
2cm above the carina
What is the name of the process of removing a patient from the ETT?
When can you remove a patient from an ETT?
Extubation
Patient needs to be;
Alert
Hameodynamically stable
Able to maintain and protect their own airway
• Have minimal secretion load
• Have enough respiratory muscle strength to breathe for themselves and cough
• Have adequate gas exchange on arterial blood gas analysis and no respiratory distress.
What procedure will be performed if a patient cannot be extubated and needs prolonged intubation and ventilation? Why?
A tracheostomy will be inserted because prolonged intubation can cause problems, such as:
– Communication difficulties
– Nutritional issues as the patient must be nil by mouth
– Oral pressure sores
– Poor patient comfort. The ETT can make patients gag, so sedation is often (but not always)
required
– Poor tube security – a risk that the patient can be accidentally extubated, so it can limit rehabilitation.
What is capnography?
Capnography (EtCO2) measures end tidal CO2 (which is the same as arterial CO2: 4.7 - 6kPa) i.e. the CO2 at the airway on expiration
Every patient with an artificial airway will have this monitored
Normal EtCO2 = 35 - 45 mmHg or 4.7 - 6kPa
What would low EtCO2 mean?
What would high EtCo2 mean?
What would a sudden loss in EtCO2 mean?
Low =Increased RR. (hyperventilation/hypocapnia)
High= Resp depression (hypoventilation/hypercapnia)
Sudden loss= no resp activity, vent defect, kinked tube, tube has migrated.
After how many days should an intubated patient be progressed on to a tracheostomy?
2 - 10 days and patient must be stable
What is a tracheostomy?
A tracheostomy is an artificial airway used to bypass the upper airways. It is a tube that connects the trachea to the outside of the body
They can be inserted surgically (in severe cases) or percutaneously at beside using a dilation technique
Why would a tracheostomy reduce the work of breathing?
A tracheostomy reduces the anatomical deadspace of the upper airways, thereby reducing work of breathing.
Name the different types of tracheostomy?
Single and double lumen
Fenestrated and non-fenestrated
Cuffed and uncuffed
What is the difference between a single and double lumen?
Double lumen tracheostomies have an inner tube which can be removed and cleaned. This inner tube is changed every 4hrs. The inner tube sits inside the tracheostomy tube & can be removed.
Single lumen tracheostomies have no inner tube & need changing every 7 days as they become blocked if patient has dry secretions.
Difference between cuffed and uncuffed tracheostomies?
Cuff is a plastic balloon that sits around the tracheostomy. It helps to keep a seal when the patient is receiving positive pressure ventilation - it maintains the set pressure/tidal volume and Positive Expiratory End Pressure (PEEP).
All gas entering/leaving the lungs goes through the tracheostomy & does not escape through the mouth/nose so the natural humidification systems of the mouth/nose are bypassed causing increased risk of impaired mucociliary clearance and secretion plugging; for this reason, all tracheostomies must be humidified.
Most patients that have a tracheostomy inserted will have a cuffed tracheostomy. Uncuffed tracheostomies are used for long term patients that do not require PEEP and in paediatrics.
What is a fenestrated tracheostomy?
What is a particular feature of the fenestrated tracheostomy?
Why is a non-fenestrated tube used for suctioning?
Fenestrated tracheostomies have a window in the tube. If the tracheostomy tube is double lumen, the inner tube will also be fenestrated, unless you are suctioning the patient – in which case a non- fenestrated inner tube will be inserted for the procedure. The hole allows patient to breathe either through the trachy or through their mouth so this is useful in the weaning process as it reduces resistance to airflow
A non-fenestrated tube prevents trauma from the suction catheter hitting the mucosal wall via holes in the tracheostomy during suctioning
Describe how you would wean a patient from a tracheostomy?
- Cuff deflation and possible fenestrated tracheostomy inserted. Patient must be able to to manage their own secretions & to generate sufficient tidal volumes.
- Finger occlusion test is performed to determine if a one-way speaking valve can be inserted at the end of the tracheostomy. The one-way speaking valve allows patients to breathe through the tracheostomy. Finger occlusion test is placing a finger over the end of the tracheostomy tube when the cuff is deflated & it redirects air through the mouth e.g. Passy Muir speaking valve
Why is a one-way/ Passy Muir speaking valve beneficial?
- Improved speech and swallow
- It helps to ‘normalise’ upper respiratory tract (air is flowing where it is anatomically designed to) Reduces atelectasis by generating physiological PEEP
- Improves smell and taste by allowing air to pass through the nasal structures
- Helps with core muscle activation (important for rehab and toileting in particular) by allowing the patient to perform a Valsalva manoeuvre
- Facilitates normal coughing, as the glottis is able to close
- Improves the patient experience by allowing them to communicate more effectively
What is tracheostomy decannulation?
Decannulation cap:
Complete occlusion of the tracheostomy tube for up to 4 hours.
This means removal of the tracheostomy tube
The stoma site will be covered with a dressing
Patients will need to be advised to cover (put pressure on) the stoma when coughing to prevent air escaping through the stoma.
