Questions Flashcards
Describe the use of the oesophageal stethoscope , from your own experience can you explain how you would check and prepare this piece of equipment for use?
The oesophageal stethoscope is a device consisting of a blind ending fenestrated plastic tube which is attached to the tubing of an ordinary stethoscope in the place of diaphragm.
Preparation should include ensuring the tubing is the appropriate size for the patient, clean and securely connected.
The tubing should be lubricated and inserted into the oesophagus where it should be positioned to over the heart.
It is used to monitor heart and respiratory sounds.
What are the limitations of the ECG when used to monitor patients?
The electrical activity of the heart as shown on the screen bears no relation to the actual cardiac output of the heart.
In cases of EMD electrical activity can be displayed in the absence of cardiac contraction.
What patient abnormalities can be detected by an ECG monitor?
Ventricular premature contractions and other arrhythmias which may indicate problems such as electrolyte abnormalities, hypoxia, hypercapnia
What are the 2 methods of monitoring arterial blood pressure in patients?
Direct (intra-arterial)
or
Indirect (Doppler or Oscillometric)
Explain the difference between the Doppler and Oscillometric blood pressure monitors
Doppler – a small ultrasound probe is placed over a peripheral pulse point using conducting gel. A whooshing sound which represents arterial pulsation should be audible. A cuff is placed separately further up the limb and manually inflated sufficiently to occlude blood flow. Readings are then taken from the monitor as the pulse becomes audible during deflation of the cuff.
Oscillometric – cuff is connected directly to monitor which inflates and deflates automatically. Detects oscillations in the artery as blood flow returns.
From your own experience give one reason why a Doppler blood pressure monitor may provide an inaccurate reading.
Cuff placement incorrect Cuff size incorrect Inadequate contact- too heavy Not enough gel Connection or battery failure
Describe the technique used to monitor Central Venous Pressure
The jugular vein is catheterised with a central venous catheter. This should lie around the intra-thoracic vena cava and is attached to a 3 way tap with i/v fluids and a manometer on each limb. The equipment is positioned level with the right atrium and filled with fluid, the tap is then turned to equate with the manometer line.
What is the function of a respiratory monitor or ‘Ap Alert’?
This provides a numerical display of the respiratory rate and may include an alarm if there is no air movement. It is often set to bleep with each breath.
What information does a pulse oximeter give regarding the anaesthetised patient?
This equipment measures the patients haemoglobin oxygen saturation (SpO2) this gives an indication of how well ventilated the patient is.
When using a pulse oximeter what SpO2 reading would be considered ideal in an anaesthetised patient?
Should be greater than 95% (90-95 may be acceptable)
What is the purpose of a capnograph and what are the 2 types of analysers?
Assesses adequacy of ventilation by assessing ETCO2 that is the CO2 exhaled at the end of expiration which should be equivalent to blood paCO2 at that point. It is non invasive and there are two types; Mainstream analysers that give a more rapid response but are bulky or Sidestream analysers which do not increase dead space significantly and therefore are more suitable for small patients.
In which circumstances would ETCO2 increase above the normal reference range?
Hypoventilation which could be due to respiratory depression eg. if the patient is too deeply anaesthetised or pre-existing lung disease
List one cause of the baseline capnograph trace failing to return to zero
This implies rebreathing, either caused by circuit failure, exhausted soda lime, inadequate FGF, excess dead space
