Monitoring Equipment Flashcards
How can temperature be monitored?
- rectal and aural probe
- thermistor probe (inside an oesophageal probe)
How should a thermometer be prepared?
Ensure clean, working and apply a cover/lube
What is the normal temperature range for dogs ?
38.3-38.7C
What is the normal temperature range for cats?
38.0-38.5C
What preparations are required for using an oesophageal stethoscope?
Ensure clean, correct size and securely connected to patient. Use lubricant to insert into the oesophagus.
What is an oesophageal stethoscope used for?
- auscultating HR, quality etc
What does an ECG show?
Electrical activity of the heart ( does not measure Cardiac output)
- Can detect premature ventricular contractions and arrythmias
How is an ECG attached?
Via electrodes
- Red to Right Forepaw
- Yellow to Left Forepaw
- Green to Left Back
- Black to Right back
What two ways is BP measured indirectly?
- Doppler
2. Oscillometric
Describe how a doppler is used to measure BP
- A small ultrasound probe is placed over a peripheral pulse with conducting gel between
- A cuff is placed further up the limb and manually inflated to occlude blood flow
- The cuff is slowly deflated and the reading is recorded using a sphygmomanometer
Describe how an Oscillometric machine is used to measure BP
- A cuff is attached at the same level as the heart.
- Cuff is automatically inflated and deflated from a machine which then records the oscillations in the blood flow as it returns
What errors can occur when taking blood pressure?
- cuff size
- incorrect placement
- inadequate/too heavy contact
- not enough gel
- battery failure
Describe how BP is measured directly
Arterial catheter is inserted and connected to a saline fluid bag and a pressure transducer or manometer and a 3-way tap.
Why is a BP measurement a useful tool?
- alerts you if compromised blood flow to vital organs
- helps avoid hypotension
- provides CVS information
What can cause a low BP reading?
- hypovolaemia (haemorrhage or drugs)
- vasodilation due to deep anaesthesia or drugs
- sepsis
- abnormal heart rhythm
- reduced cardiac contractility
What can cause a high BP reading?
- patient not adequately anaesthetised
- not enough analgesia
- drugs
- hypoxia/ hypercapnia
- hyperthermia
What is a normal ETCO2 reading?
35-45mmHg
What is ETCO2?
End tidal carbon dioxide level - measures the level of co2 left in the alveoli and gives an indication of the partial pressure of co2 in the arteries (i.e. the CO2 level in the blood).
This gives information on the adequacy of respiration
What may an increased ETCO2 indicate?
- hypoventilation
- anaesthetic too deep
- increased metabolism
- increased CO or addition of CO2 into the circulatory system (due to rebreathing)
What may a decreased ETCO2 be due to?
- hyperventilation
- leak in ET tube
- fresh gas contamination
- Low CO and therefore low blood volume delivered to lungs
- Rapid call may pre-empt cardiac arrest
What could hypoventilation during anaesthesia be due to?
- anaesthetic too deep
- drug overdose
- drugs that depress respiration
- ET tube too long and only ventilating one half of lungs
- Increased pressure in abdomen / on diaphragm
- Low body temperature
What could hyperventilation during anaesthesia be due to?
- anaesthesia too light
- inadequate pain relief
- surgical stimulation
- hypoxia
- iatrogenic (IPPV too heavy handed)
- hyperthermia/pyrexia
What can apnoea during anaesthesia be due to?
- drug effects (e.g. Propofol)
- administration of NMBAs
- cardiac arrest
- Pressure build up in circuit e.g. closed APL valve
What would an elevated baseline on a capnograph indicate?
- not enough fresh gas/ exhausted soda lime
What would no trace on a capnograph indicate?
- Apnoea
- Airway obstruction
- Disconnection
- Ventilation failure
How should a capnograph be prepared and attached?
Prepared - leads and screen damp dusted and sterilised (avoid corrosive chemicals). Plug in or check battery.
Attached - Probe attached to an analyser. The probe sits between the ET tube and the breathing system.
What does a pulse oximeter measure?
Measure Hb oxygen saturation (SPO2) - gives an indication of how well-ventilated the patient is.
What can interfere with a pulse ox reading?
- Incorrect placement of probe
- Too much ambient light
- Pigmented skin
- Patient vasoconstricted due to alpha 2 drugs
What is a normal pulse ox reading?
> 95%
What is the difference between a mainstream and a side-stream analyser capnograph?
Mainstream: CO2 measured directly in the breathing system with a chamber inserted between the ET tube and the circuit. Bigger.
Side-stream: Sample port and tube attached to circuit. Sucks out exhaled air and measures the CO2. Smaller and therefore more suitable for smaller patients
