T5: Getting the Patient Ready for Theatre Flashcards
What are some procedures that may need to be performed to stabilise an animal?
- Clearing the airway
- Administration of oxygen via mask
- Intubation -may require lignocaine gel or spray
- Control of haemorrhage -apply direct pressure
- IV fluids
What is the aim of pre-operative stabilisation?
to reduce the patient’s anaesthetic risk so that their chances of surviving surgery are increased.
What is IPPV?
Intermittent Positive Pressure Ventilation
breaths performed manually by the nurse using the breathing bag or by a mechanical ventilator
Name some situations where the vet may require the veterinary nurse to assist with controlling the patient’s ventilation during anaesthesia
- apnoea
- hypoventilation
- obesity
- thoracotomy
- muscle relaxant use
- diaphragmatic hernia
What is hypoventilation?
- abnormally low alveolar ventilation (i.e. the volume of gas delivered to the alveoli each minute is less than normal)
- caused by a reduction in the tidal volume (size of breath) and/or a reduction in the respiratory rate.
- Hypoventilation can lead to hypercapnia (an increase in expired carbon dioxide levels).
How may obesity cause breathing difficulties during anaesthesia?
- Subcutaneous, intrathoracic and abdominal fat deposits may prevent adequate expansion of the chest and lungs
What type of ventilation is required during a thoracotomy?
- PPV -ongoing ventilation, not intermitent
- as the chest is opne, animal cannot breath for itself
- mechanical ventilator often used
How may a diaphragmatic hernia interfere with a patients breathing during anaesthesia?
- diaphragm contributes little to the expansion of the lungs and even very light anaesthesia may cause severe ventilatory depression
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When using manual IPPV, what is the maximum breath size?
not greater than 20cm H2O
What is the normal ventilatory rate for:
Cats?
Dogs?
Adult horses?
Foals?
- 15 breaths/min (cats)
- 8 breaths/min (large dogs)
- 4-6 breaths/min (adult horses)
- 8-10 breaths/min (foals)
Describe how you would place an IV catheter
- In either cephalic, jugular and medial and lateral saphenous veins.
- can be left for long periods of time (>72hrs) if properly maintained, and flushed w/ heparin saline every 4-6hrs.
- Immobilsed and hold off vein
- insert catheter w/ bevel up at 15degree angle
- look for flash of blood, reduce angle of catheter to parallel w/ vein
- advance, look for flash in chamber, advance fully
- tape and plug
What is maintenance fluid rate?
2.5-3ml/kg/hr or 60ml/kg/day
For neonates or presence of massive tissue injury, fluids rates should be increased by a factor of…?
1.3
How quickly should a fluid deficit be replaced?
- over 48 hours:
half in the first 6-8 hours
three quarters after 24 hours
and the remainder by 48 hours
Name the fluid used for routine fluid maintenance during surgery
Hartmann’s
What characteristics should a canine blood donor have?
- current vaccinations
- tested negative for heartworm microfilaria
- be receiving heartworm prophylaxis
- not have received a blood transfusion
- PCV greater than 35% immediately prior to blood collection
What characteristics should a feline blood donor have?
- tested negative to feline leukaemia virus and feline immunodeficiency virus
- be receiving heartworm prophylaxis.
The volume of blood collected from the donor on each occasion should be limited to:
- 16ml/kg for greyhounds
- 12ml/kg for other dog breeds
- 10ml/kg for cats
Name the antcoagulant used in blood collection bags
Citrate Phosphate 2x Dextrose with Adenine (CP2D-A)
How may collected blood be stored?
- be stored for four weeks at temperatures of 2-6°C.
- Gentle agitation of the pack every day or so to mix the red cells, will optimise its condition.
- Blood for patients with thrombocytopenia should be stored at about 20°C and administered within 6 hours
- Refrigeration inactivates platelets.
Which canine blood type are universal blood recipients?
DEA 1.1
can receive a first transfusion of any type without developing a transfusion reaction
Clinical signs of a transfusion reaction include:
- pyrexia
- vomiting
- salivation
- trembling
- elevated heart rate
- urticaria (raised itchy areas of skin)
- hypotension (leading to shock)
What does blood cross-matching involve?
- separation and washing of red cells from the donor and recipient.
- Donor cells are then mixed with the recipient’s plasma (“major cross-match”) and the recipient’s cells are mixed with the donor’s plasma (“minor cross match”).
- Incompatibility is indicated by aggregation (clumping) of the red cells.
At what rate should you administer a blood transfusion?
- initial rate of transfusion is slow (0.2 ml/kg/minute for 20 minutes) and the patient is observed for signs of a transfusion reaction.
- A normovolaemic animal should not receive blood at a rate greater than 1.5 ml/kg/hour.
