Monitoring a patient Flashcards
Stethoscope
allow measurement and rate of rhythm
Normal heart rate for dogs - 60 - 100bpm
normal heart rate for cats - 160 - 200bpm
normal respiratory rate for dogs - 10-30 bpm
normal respiratory rate for cats - 20-30 bpm
oesphogeal stethoscopes
used to measure heart rate
manually check heart rate and rhythm
Electrocardiogram - ECG
allows us to understand the electrical activity of the heart
electrical activity starts at the sino atrial node
an ecg is a visual representation of the hearts electrical activity and quality/ rate of the contraction of the myocardium
Disatole
point of relaxing
ECG Wave (P)
P Wave - contraction of the atria
ECG wave (PR Interval)
AV node stimulated and slowly conducts from atria to ventricles to allow a coordinated ventricular contraction
ECG wave ( QRS Complex)
contraction of ventricles
ECG Wave ( T Wave)
repolarisation for next contraction
ECG Placement
red - right forelimb
yellow - left forelimb
green - left hind limb
black - right hind limb
white - general placement on the side
ECG Considerations
ECG describes electrical activity of the heart
rhythm can be traced on the graph and any abnormalities certain systemic abnormalities and cardiac pathology
Capnography
Based on the measurement of exhaled CO2 (end tidal carbon dioxide)
measured by gas withdrawn from small tube between the circuit and ET tube
Normal end tidal co2 vollumes are 40 - 55 mm Hg
Pulse Oximetry
Non invasive technique which monitors the degree to which Hb is saturated with oxygen
displays animals heart rate
attached to multiple points of the body
- tongue
-non pigmented skin
Pulse oximetry
threshold for hypoxaemia is usually at an arterial oxygen tension of 60mm Hg
this corresponds to a Hb oxygen saturation of 90%
during anaesthesia oxygen needs to be above 90%
pulse oximetry considerations
gives no indication of available haemoglobin
lack of perfusion will prevent a signal being obtained e.g. tissue compression of the probe
light interference from surgical lights can cause inaccuracies
Blood pressure
systolic
dog - 110 - 190
cat - 120-170
diastolic
dog - 55-110
cat - 70 - 120
in general anaesthesia, we aim to maintain arterial blood pressure above 70 - 80 mm
direct blood pressure monitoring
invasive and is one of the most useful indicators of cardiovascular function
central venous pressure is measured in the central veins close to the heart
indicates mean right atrial pressure and is frequently used as an estimate of right ventricular preload
measured in the thoracic vena cava using a long IV catheter
risks of introducing infection and haematoma formation
Indirect blood pressure monitoring
a doppler probe contains two piezoelectric crystals which should sit at a right angle to a peripheal artery
Common arteries used include the metacarpal, dorsal metatarsal, planter metatarsal and coccygeal artery
probe can be taped into place over the artery before turning on loudspeaker, and minor adjustments made to the positioning as necessary to obtain best quality sound.
headphones may be used to reduce theatre noise levels
oscilometer blood pressure monitoring
can be obtained with the use of an inflatable cuff around limb or tail base,k which is attached to monitor
measurement is automatic and allows detection of oscillations produced by the artery wall as the cuff deflates
meaures thr systolic mean and diastolic pressure
digital thermometer
a thermometer is used to monitor patient temperature
the tip of the thermometer is lubricated placed into rectum of the patient
normal range for a dog should be 38.3 - 38.7
normal range for a cat - 38 - 38.5
Blood Gas Analysis
measures PH
should contain no air bubbles
2 types of blood gas analyser
oxygenation
ventilation
the acid base status of the patient
Cranial nerve reflexes
caused by the cranial nerves
cranial reflexes are checked on anaesthetised patients
measures depth of anaesthesia, to consider if a patient is too light, or deep in depth of anaesthesia
palpebral reflex
tapping the corner of the eye will result in blinking, indicates light anaesthetic, no blinking indicates a good depth of anaesthesia
Eye position and Pulpillary diameter
when eyes are positioned in the corners this is adequate, but a central position with small pupil indicates light anaesthetic and central with dilated pupil indiactes deep anaesthetic. Some drugs may affect the accuracy of this reading however, such as Ketamine
Jaw Tone
when the jaws are loose and slack, the patient is adequately anaesthetised. tight jaws which are difficult to open indicate light anaesthetic