Fluid therapy Flashcards Preview

URI > Fluid therapy > Flashcards

Flashcards in Fluid therapy Deck (55)
Loading flashcards...

List ways in which healthy animals lose body water

- Urine
- Sweat
- Water vapour during breathing
- Faeces


List abnormal ways in which water can be lost from the body

- Vomiting
- Diarrhoea
- Burns
- Haemorrhage
- Polyuria
- Third space oss


What is third space loss and give an example?

- Fluid accumulates in body cavity but lost from circulation i.e. effusions, internal haemorrhages, peritonitis, obstructions etc
- e.g. ascites


What are the kinds of fluid losses that can occur in an animal?

- Primary water loss
- Mixed water and electrolyte loss


How does primary water loss occur?

- Water intake decreased, only losing water
- Hypotonic loss
- When patient unable to increase intake sufficiently
- Occurs from ECF, ICF to ECF translocation to compensate


Why do the clinical signs of primary water loss take time to develop?

- Water moves from ICF to ECF to compensate
- ICF is a large reserve


What are the important factors to consider when estimating water loss?

- Duration of illness
- Vomiting/diarrhoea? frequency and volume
- Water intake (quantify, unusual habits)
- Source of loss e.g. open wounds, asscites ec
- What kind of fluid loss has occured


How does mixed water and electrolyte loss occur?

- Vomiting or diarrhoea
- Haemorrhage and effusion


What are the important features of mixed electrolyte and water loss?

- Osmolarity does not change, no movement from ICF
- Loss borne by ECF alone
- Clinical signs develop quickly


What should be included in patient assessment when considering fluid loss?

- Pulse quality (peripheral, changes sooner)
- CR
- Heart rate
- Skin tenting
- Regular blood pressure (can change with stress, may no be accurate)
- Tackiness of mucus membranes
- Eye position
- Demeanour


What may happen to eye position in severe dehydration?

- May sink into socket
- Third eyellid (nictitating membrane) may move over the top


How can the degree of hypovolaemia be assessed?

- Using approximate ranges for heart rate, pulse quality, mucous memrbane colour, CRT, mentation and extremity temperature


What does loss of a distal pulse indicate?

Severe hypovolaemia


What is the difference between cats and dogs as hypovolaemia progresses?

- Cats more likely to show bradycardia
- Dogs more likely to show tachycardia


How can fluid deficit be estimated?

- %age
- Comparison of clinical signs usually show when at a particular % fluid deficit
- Multiply by animal's weight to get volume of deficit i.e. 20kg dog with 10% dehydration = 2 litre deficit


What is the approximate maintenance fluid requirement for a dog?

- or 1.5-4ml/kg/hour


List the main therapeutic fluids

- Crystalloids (hypotonic, isotonic, hypertonic)
- Colloids
- Blood products
- Haemoglobin based oxygen carrying solutions (HBOCS)


What are the main aims of fluid therapy?

- Improvement of organ function (need adequate perfusion)
- Correction of electrolyte disturbances
- Correction of hypovolaemia
- Correction of acid base disturbances
- Total or partial parenteral nutrition (usually PPN)


What is Lactated Ringer solution?

Isotonic crystalloid solution


What is contained in LRS?

- Na+: 130mEq/l
- Cl-: 109mEq/l
- Lactate as a bicarbonate precursor (so is buffered)
- Tiny amounts of potassium


Why is LRS buffered?

- Controlled alkalinisation
- Avoids dilutional acidosis


Why is LRS not suitable for long term administration?

Inadequate potassium


What is LRS used for?

- Shock
- Diuresis
- Anaesthesia
- Maintenance
- Can add other things e.g. glucose


What are the disadvantages of LRS?

- Contains calcium, cannot use if hypercalcaemic
- Only 1/4 will remain in vascular space, rest is excreted, not efficiet in bringing up and maintaining fluid levels


Describe hypotonicc crystalloid fluids

- 0.18% NaCl, or 0.18% NaCl and 5% glucose
- Hypotonic
- Very few indications - Like giving pure water
- Useless, causes dilution, likely to make patient sicker


What is the effect of administration of hypertonic crystalloid fluid?

- Draws water from interstitial space
- Causes pulmonary-vagal reflex (vasoconstriction, bypass pulmonary circulation)
- Transient effect (10-15 min)


When is use of hypertonic crystalloid fluid indicated?

- Usually large animals e.g. prior to colic surgery
- Low volume resus (life threatening hypovolaemia and raised ICP)


When is use of hypertonic crystalloid fluid contraindicated?

- Hypernatremia
- Hypokalaemia
- Haemolysis
- Thrombosis
- Fall in BP
- Repeat use


When is use of colloid fluids indicated?

- Support of circulating blood volume is needed
- Severe hypovolaemia
- Systemic inflammatory response syndrome
- Haemorrhage
- Hypoproteinaemia


What types of colloid fluids are available?

- Artificial: oxypolygelatins, dextrans, starches, HBOCs
- Natural: albumin, plasma etc