Purposes of Fluid Therapy

Intravenous Fluids

 

Sub-Cutaneous Fluids
What Are They?	Why Use Them?	When to Use Them	Types of Fluid	Obtaining Fluids
Amount to Give	Frequency	Will I Always Have to Give Them?	How to Give Them	Coping with Giving Them
Using a Giftube or Endo-sof Catheter
Winning Your Vet's Support
When Not to Give Sub-Cutaneous Fluids

Introduction

In  many ways, fluid therapy in the particular form of sub-cutaneous fluids (hereafter referred to as sub-Qs, but usually known as sub-cuts in the UK), is the raison d'être for this website. I am absolutely certain that Thomas would have died back in January 2000 without sub-Qs - yet sadly, they are a very rare treatment in most parts of the world apart from Canada and the USA. The quotation above expresses very clearly my hopes for the use of sub-cutaneous fluids gradually becoming a standard treatment for CRF cats throughout the world.

Purposes of Fluid Therapy

According to Colorado State University College of Veterinary Medicine, fluid therapy is given for three purposes:

• the emergency phase - during this phase, the goal is usually to stabilise a critically ill animal who has lost a life-threatening amount of body fluids, e.g. because of a road accident. Intravenous fluids are commonly used for this purpose;

• the replacement phase - during this phase, the goal is to correct dehydration, which may be very severe in some cases. Intravenous fluids are commonly used for this purpose;

• the maintenance phase - during this phase, the goal is to keep the cat hydrated, so s/he does not revert to the replacement phase. Sub-cutaneous fluids are commonly used for this purpose.

Intravenous Fluids (IV)

In terms of CRF cats, IV fluids are commonly used for severely dehydrated cats. IV is a form of fluid therapy whereby a special type of fluid with the correct balance of electrolytes (salts required by the body) is administered to a cat via a drip feeding into a vein (intravenous). This is a skilled form of treatment, and great care needs to be taken to ensure the rate of fluid flow is correct for the cat - too fast a flow can be dangerous (it can overtax the heart), too slow a flow may not rehydrate the cat quickly enough. For this reason IV is usually undertaken at the vet's office, where the cat can be carefully monitored. 

IV fluids are a type of diuresis, a kind of flushing through of the kidneys, which is designed to correct an acute crisis situation of severe dehydration and any resulting electrolyte imbalances, and to remove toxins from the blood. It is not a suitable treatment for ongoing hydration purposes: it is too taxing on the kidneys and, since it increases the GFR (see What is CRF?), it could accelerate the loss of kidney function if done for too long; plus of course it entails a stay in the vet's office which many cats find very stressful. 

IV fluid treatment is commonly used for CRF cats when they crash (suddenly become severely dehydrated and very ill), or if they have high bloodwork values (say creatinine over 7) when they are first diagnosed, when they are also often quite dehydrated. In such cases the cat may need to be on a drip for several days in order to restore the correct level of hydration and re-balance electrolytes - Thomas was on IV twice, the first time for four days, the second time for three days.

One day on IV is unlikely to be sufficient for most cats to restore hydration and some degree of balance; so I am growing increasingly concerned recently at the number of vets who offer just one day on IV, tell the person their cat's numbers have not improved after that short stint, and recommend euthanasia. In most cases this is inappropriate in my opinion. Yes, not every CRF cat can be saved; but euthanasia is an irrevocable decision so you need to be very sure, and for most people that means giving their cat every chance.

For a severely ill cat, one or two days on IV are simply not going to be long enough, so I would recommend that you make sure that your cat is given a reasonable stint on IV. It is also important that IV fluids are not stopped abruptly, particularly in cats with high numbers - the cat's body needs time to adjust to being without fluids, so the vet should gradually reduce the amount of fluids being given via IV. You can then take your cat home and continue with sub-Qs fluids. It is very important in most cases that the cat is given a reasonable chance of success at home after being on IV fluids. Being at the vet's is very stressful for most cats, and they often need a few days at home convalescing before they begin to act better.

On the other hand, I have heard recently of some vets putting cats with low or medium level numbers (creatinine around 260-300, or US 3-3.5) on IV fluids. In most cases this is unlikely to be necessary, though may be appropriate if a cat is very dehydrated for some reason and/or has a kidney infection.

Many American vet offices do not have anybody on the premises overnight. I personally would not feel at all comfortable leaving a cat on IV fluids unattended. If your vet recommends IV fluids for your cat, but s/he would be left alone overnight, a possible compromise is for your cat to be on IV fluids at the vet's office during the day, but to come home (with catheter still in paw) overnight; ideally though, your cat should be on IV fluids continuously but under supervision. 

If your cat is on IV fluids at the vet's, make sure that s/he is also being fed. Many vets place food in front of a cat on IV but do not make sure the cat eats. Your cat will do better if s/he keeps his/her strength up by eating. If necessary, offer to go on and feed your cat yourself each day. The Persuading Your Cat to Eat page has tips on getting food into your cat.

If your vet believes IV is the best treatment for your cat, you should give it very serious consideration - it really can be lifesaving. In Management of chronic renal failure: beyond the can (2001), a presentation to the Atlantic Coast Veterinary Conference 2001, Dr Melissa Wallace explains more about when and how to use IV fluids.

Here is our George on IV. George was extremely ill at this time (with liver disease, not CRF); hopefully your cat will not look so sick.

Sub-Cutaneous Fluids

What are Sub-Cutaneous Fluids (Sub-Qs)?

Sub-cutaneous means under the skin; and so sub-Qs, commonly known as sub-cuts in the UK, are a way of hydrating the cat by carefully introducing fluids under the skin, rather than into a vein; this means that a trained layperson can do it. Instead of placing a slow drip of fluids into the cat's vein, as happens with IV, the fluid is injected just under the skin with a needle, which only takes about five minutes. The fluid then gradually disperses throughout the cat's body, and helps him or her to maintain hydration at the correct level. 

The fluids used are particular types of fluid with the correct balance of electrolytes. There are various types of fluids available (see below) and your vet can select the fluid most suitable for your cat. 

Why Use Sub-Cutaneous Fluids?

The cat is an unusual animal in that it has the ability to concentrate its urine, a little like a camel; this is believed to be a legacy of its African heritage. However, in cats with CRF, this ability gradually disappears, and cats then produce a very dilute urine: the urine looks weaker in colour, has little odour, and the cat will often produce copious amounts. 

This increase in urination leads the cat to drink more and more in order to try to avoid becoming dehydrated; and for a time the cat can manage to maintain some kind of balance. Eventually, however, the cat simply cannot drink enough to keep up with its urination rate, and dehydration (which means a loss of body fluids and an imbalance of electrolytes necessary for proper function) occurs. Sometimes this becomes so severe that the cat crashes (i.e. becomes dehydrated enough to need IV treatment at the vet's), as happened to Thomas. 

Even if your cat does not suffer such a crisis, the ongoing low-level dehydration that accompanies CRF can be debilitating and uncomfortable; can cause toxin levels in the blood to rise; and without sub-Qs, blood flow through the kidneys reduces and the kidneys deteriorate even more. Human CRF patients have described dehydration and the accompanying high levels of toxins in the blood as feeling similar to a bad hangover: so the purpose of sub-Qs is to keep your cat nicely hydrated (which should have the side effect of reducing toxin levels to some extent); to try to maintain kidney function; and to improve his or her well-being by removing that hungover feeling.

When To Use Sub-Cutaneous Fluids

Although sub-Qs can be of great benefit to cats who need them, not all CRF cats need them immediately. As mentioned in the previous section, the purpose of sub-Qs is to keep the cat hydrated enough to avoid dehydration occurring. However, cats with early stage CRF can usually drink enough to offset their increased urination, and thus do not become dehydrated even without sub-Qs.

Processing sub-Qs in itself places an additional workload on the kidneys, plus it can flush out certain nutrients; and giving fluids when they are not needed may increase blood pressure and increase the risk of overhydration. Therefore it is best not to begin fluids until the advantages are likely to outweigh the disadvantages i.e. when a cat would become dehydrated without them.

Dr Katherine James of the Veterinary Information Network believes that this tends to happen and that most CRF cats will benefit from sub-cutaneous therapy once creatinine levels are consistently over 300 -350 (US: 3.5-4). If your vet thinks your cat's CRF is less advanced than this, and your cat does not appear dehydrated, then it is probably safer to hold off on sub-Qs for the moment (it also means you and your cat do not need to add sub-Qs to your daily routine immediately). However, there are exceptions, and some cats with creatinine below 300 (US: 3.5) may need sub-Qs, particularly if they were originally diagnosed with very high numbers. And any CRF cat who is a bit below par because of vomiting or diarrhoea causing dehydration may benefit from sub-Qs as a one-off - my vet gave sub-Qs to my non-CRF cat when she had severe vomiting and diarrhoea for this reason.

Types of Fluid

Please always check the bag of fluid before you start to use it: mistakes can happen. Common fluid types are

• Lactated Ringers Solution (LRS)

• Normosol-R/Isolyte-S/PlasmaLyte A

• Saline Solution

• Dextrose

Washington State University discusses the different fluid types in detail.

International WIN also shows the contents of common fluids.

Lactated Ringers Solution (LRS)

Many people on the Feline CRF Information list use lactated ringer's solution (LRS); the nearest British equivalent (it is virtually identical) is called Aqupharm No. 11 Hartmann's solution. Lactate is important in fluids for CRF cats because lactate is metabolised by the liver where it is converted to bicarbonate, and this aids in the correction of mild acidosis; human patients with renal failure are given solutions containing a buffer such as lactate. The bags of Hartmanns come in 500ml or 1 litre bags, and the latter work out cheaper to buy. 

Normosol-R/Isolyte-S/PlasmaLyte A

This is a type of fluid which is sometimes used instead of Lactated Ringers when a cat has high calcium levels, liver problems or lymphoma (a form of cancer). They are all basically the same type of fluid, but different manufacturers use different trade names.

If you are using Normosol, you need Normosol-R, not Normosol-M: the latter contains dextrose (see below). Normosol-R is sometimes called Plasmalyte. 

These products contain magnesium, so may not be suitable if your cat has high magnesium levels; they also seem to sting some cats or make them twitch, so cats may resist being given this type of fluid. There have been quite a few reports of cats vomiting after being given this type of fluid. All of these products are also more expensive than Lactated Ringers. I therefore recommend that, if at all possible, you should LRS instead.

Saline Solution (NaCl)

Saline solution is sometimes suitable for cats with high calcium levels, but it is usually too acidic for a CRF cat, plus it can sting when injected sub-cutaneously which may make the cat resist fluids; it also lacks the buffer mentioned above under Lactated Ringers, and does not have added potassium, which many CRF cats need. It is also not usually suitable for cats with hypertension or liver problems. However, it may be helpful for cats with hyperkalaemia (high levels of potassium).

Dextrose

These fluids contain dextrose, a form of sugar. The sugar means that bacteria can easily grow in the fluid and cause infection at the injection site; fluids containing dextrose may also sting when administered via sub-Qs. Fluids containing dextrose also have a shorter life than non-dextrose fluids. If your vet gives you this fluid (it may be a bag of LRS to which 2.5% or 5% dextrose has been added, so always check bags carefully before using them), ask to exchange it for a more suitable type. Pet Place discusses the need to avoid giving sub-Qs with added dextrose.

Obtaining Fluids

In the US and Canada, people can buy supplies very cheaply from on-line pharmacies (see Obtaining Supplies Cheaply). It can be harder to find such resources in the UK, but the Obtaining Supplies Cheaply page does contain information about two such companies which can provide fluids relatively cheaply. 

If you can come to an agreement with your vet, it may work out cheaper to obtain fluids and needles direct from him/her rather than pay shipping costs. Whichever method you choose, it can also make a big difference cost-wise to buy in bulk. Our vet ordered five bags of fluid at a time for us, which lasted us 25 days; supplies for your cat might last longer (don't forget, Thomas received 200ml of fluid a day). Our vet gave us a discount (for which we were very grateful) so the approximate cost of giving fluids for us was around £8-9 a week - it would have been much cheaper if we had used a giving set, the main cost for us was the butterfly needles - without these the cost would have been around £5 a week plus the initial cost of the giving set. Many cats need less fluid than Thomas, which would also reduce the cost.

Amount of Sub-Cutaneous Fluids

This is something you need to discuss with your vet. Dr Katherine James believes that generally speaking, cats do not need more than 100ml a day, though there are always exceptions, for example if your cat is particularly large or particularly small.

This is purely a hunch of mine, but I suspect that some cats who have had severe crashes may possibly require more fluids than cats who are diagnosed early and whose CRF progresses gradually. Thomas wasn't a massive cat, but he still required 300ml a day to start with following his crash. Even after his creatinine level stabilised at 316 (US: 3.5), he still required 200ml a day, divided into two sessions, in order to maintain hydration.

The key words in the previous sentence are "in order to maintain hydration". Giving more than is needed to maintain hydration is a strain on the kidneys (see when to use sub-cutaneous fluids), can make a cat feel uncomfortable, and of course costs more.

Since cats vary in their individual needs, you should seek your vet's advice on how much to give your cat, and start off gradually, and aim for the lowest level that will comfortably maintain hydration. More is NOT always better - giving too much fluid can be dangerous. If you give a 10 lb cat 300ml of fluids a day, that is like giving a 150lb person 4.5 litres of water a day, far in excess of the amount recommended for most people - would you want to drink that much? Warning signs of overhydration are discussed in the Treatments section.

If your cat's bloodwork improves, or your cat seems to stop absorbing the fluids, it may be that s/he needs fewer or no fluids. Ask your vet about reducing or stopping the fluids, but this should be done gradually so as to give your cat's kidneys time to adjust. The same applies if your vet has prescribed fluids for a low numbers cat - ask about stopping fluids to see how your cat manages, but do it slowly.

If you wish to monitor your cat's need for fluids, the simplest way is probably by means of a weighing scale; you can weigh your cat regularly and if his/her weight goes down, this may indicate dehydration. Coco's page has more information on how to do this, and the Treatments page has information on obtaining accurate scales.

Colorado State University briefly discusses fluid therapy and assessing dehyration.

Coco's Page has information on calculating how much fluid is necessary, though please do not alter the amounts you give without your vet's knowledge and approval.

Frequency of Sub-Qs

Again, this depends to a large extent upon your cat's individual needs. Some cats on the Feline CRF Information list only need fluids twice a week; whereas others, like Thomas, become dehydrated very quickly without twice daily fluids. Discuss your cat's particular requirements with your vet, and aim for a consistent, frequent and regular approach.

It is usually better to give smaller amounts more often, e.g. to give 100ml every day rather than 200ml every other day. If you think about it, this makes sense - if you drink 8 pints of water each day, it is better if you drink 8 each day rather than 16 on one day and nothing at all on the next day - the same principle applies to sub-Qs.

When deciding on how much fluid to give, you need to monitor your cat's hydration levels and whether the fluid is being properly absorbed; this is not as difficult as it sounds and tips for monitoring hydration can be found in the Symptoms section. If you have the level of sub-Qs right, your cat will no longer drink massive amounts of water.

Will My Cat Always Need Sub-Cutaneous Fluids?

If you start fluids at the right time, i.e. only when they are necessary to prevent your cat from becoming dehydrated (which for most cats occurs once creatinine levels are consistently over 300 -350 (US: 3.5-4)), then yes, your cat will probably always need them. However, there are always exceptions. Some cats may only need fluids to help them after a crisis, for example, particularly if they are young or if their bloodwork is normally reasonably good.

If you do ever try to decrease or stop sub-Qs, it is very important to do this slowly, because CRF kidneys cannot adjust to changes as easily as healthy kidneys.

How to Give Sub-Cutaneous Fluids

There are two main ways to give sub-qs, either via a giving set or via syringe. How to Give Sub-Cutaneous Fluids: Syringe Method shows how to use the syringe method, with photos of Thomas receiving his fluids, whilst How to Give Sub-Cutaneous Fluids: Giving Set Method is modelled by Thomas's friend, Purr Box. If you use the giving set method, you will need to purchase venosets as well as the fluids and needles; with the syringe method, you will need to purchase syringes as well as the fluids and needles. With either method, it is not usually necessary to wipe the area with alcohol before giving fluids (cats hate the smell of alcohol). Washington State University explains why using alcohol on the site is not necessary.

You can find additional information, including some helpful pictures of the various methods of giving fluids, at the following sites: 

Sophia gets her sub-cutaneous fluids shows how Steve gave fluids to Sophia. This is very detailed, and is the most popular website about giving fluids on the Feline CRF Information list.

Fluids: the Film is a video of a CRF cat receiving fluids. This shows a cat who is not at all bothered by the process.

Mar Vista Vet has two videos about giving fluids:

• Fluid preparation

• How to give sub-Qs

Washington State University has some clear photographs of how to use a giving set. It also shows how to give fluids using an extension set, a variant on the syringe method.

Veterinary Partner also has photographs of using a giving set.

Whiskers' page has very clear diagrams showing how to use a giving set.

Coco's page gives tips and also advice on the emotional side of giving sub-Qs.

Elisa and Samantha's page describes Elisa's routine for giving fluids to Samantha.

Washington State University College of Veterinary Medicine has information on how to restrain a cat, although it may not be necessary to do this; many cats do better if they are not restrained in any way.

• Giving sub-cutaneous fluids to cats - an owner's guide is an article by a vet from Bristol Vet School which explains how to give sub-Qs.

• In Chronic renal failure in the cat (2006) Sparkes AH Presentation to the World Small Animal Veterinary Association World Congress, Dr Sparkes, of the UK Animal Health Trust, mentions giving sub-Qs at home.

• Washington State University College of Veterinary Medicine website clearly states that "the most common reason SQ fluids are given is for prevention of dehydration in chronic kidney disease."

• Dr Katherine James is a US vet who specialises in feline renal medicine, in which she obtained her PhD. She now acts as a consultant to the Veterinary Information Network. Her website mentions sub-Qs under Some Keys to Successful Management.

• Long Beach Animal Hospital explains how they routinely teach their clients how to give sub-Qs at home (click on Home Administration).

• Vetinfo for cats - Dr Mike Richards discusses how the majority of his CRF client cats survive 1-3 years after at home sub-Qs are begun, with the record being 8 years - click on Kidney Failure: Daily Fluid Treatment.

• In Management of chronic renal failure: beyond the can (2001), a presentation to the Atlantic Coast Veterinary Conference 2001, Melissa Wallace states that if a patient "is having trouble maintaining hydration due to polyuria, then subcutaneous fluids on an ongoing schedule are very helpful, especially in cats."

• Sub-Qs Testimonials Book provides testimonials from a number of people on how successful a treatment sub-Qs have been for their cats; print this out and show it to your vet if necessary, in order to emphasise what a mainstream treatment this is in the USA and Canada.

4. if your vet feels sub-Q treatment is too invasive, ask whether your vet objects to clients giving their cats insulin objections? If not, politely ask what really is the difference between twice daily insulin injections and regular sub-Q injections?  

5. if your vet says sub-Qs are painful, ask on what this opinion is based. My vet believes that the sensation of the fluid going under the skin might feel a little strange, but she certainly does not think they are painful. It is highly unlikely that your UK vet has any experience of sub-Qs being used on a regular basis, so he/she may not appreciate how easy it is to get into a routine. Thomas did not fight fluids at all, he did not cry, he just sat quietly, and it was all over in under five minutes a session, as the photos in How to Give Sub-Cutaneous Fluids: Syringe Method show; and here are some great photos of Shelly's cats (click on We Love Kitty Stickems if necessary) and Judi's Hobbes receiving fluids with no problems at all. Fluids: the Film is a video of a CRF cat, Darla, receiving fluids. This shows a cat who is not at all bothered by the process; perhaps ask your vet to watch it.

6. Some vets think that sub-Qs are painful because they entail multiple injections, but if you give fluids the way we did or use a giving set as most Americans do, it is only necessary to insert the needle into the cat once in each session. It is also extremely important to use Terumo needles: these are incredibly sharp and slide in so smoothly, there is no comparison with other needles. How to Give Sub-Cutaneous Fluids: Syringe Method has more information on Terumos.

7. if your vet says that receiving fluids regularly could distress your cat, point out that in return for a mere 10 minutes a day treatment, your cat will receive a much better quality of life for the other 23 hours and 50 minutes in the day. If I had really thought that receiving fluids distressed Thomas, I doubt I could have brought myself to administer them; but they simply did not. Look at the pictures of Thomas being given his fluids in How to Give Sub-Cutaneous Fluids: Syringe Method and Purr Box being given her fluids in How to Give Sub-Cutaneous Fluids: Giving Set Method - you can see they are not distressed in any way.

I maintain a private list of British vets who permit sub-Qs. If you are in the UK and need such a vet, please contact me, though unfortunately the list is very short, so the chances of such a vet being in your area are sadly rather low.

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