UNDERSTANDING YOUR BLOOD RESULTS

PLEASE NOTE

The blood levels used in these notes are the guidelines set by the British Renal Association. Where there are no specific guidelines the local laboratory range is given. Your own unit may use different levels. Please check.

INTRODUCTION

When your kidneys are not working properly or if you are on dialysis (haemodialysis (HD) or peritoneal dialysis (PD), you will have regular blood tests taken. The results of these tests will show whether you need to change your diet, if the doctor needs to change your medical treatment and, if you are on dialysis, whether any aspects of your dialysis need to be changed.

There are several different blood levels tested and the main ones will be explained in the following text.

If you would like to know your own blood results please ask your doctor/nurse/dietitian. This will help you to monitor your treatment.

 

BLOOD RESULTS

 

When your blood is taken depends on the treatment you are receiving for your kidney problem.
Some of the blood results relate to your diet and can be used as a guide to how well you are eating and whether there are any problems. If any changes are necessary they will be discussed with you.
If your kidneys are not working properly, but you are not on dialysis, you will usually have your blood taken at renal clinic.

 

HAEMODIALYSIS


If you are on haemodialysis, you will normally have blood taken monthly. A sample will be taken at the start of your dialysis (a pre-dialysis blood sample) and another at the end of the dialysis (a post-dialysis blood sample). By testing these two we can compare your treatment before and after dialysis to see how well your treatment is working.

 

PERITONEAL DIALYSIS

 

If you are on PD you will usually have blood taken when your PD nurse visits you at home or when you attend your clinic appointment.


 

DRUG INDEX

CALCIUM GLUCOSE CHOLESTEROL PHOSPHATE  UREA POTASSIUM ALBUMEN CREATININE PARATHYROID HORMONE WEIGHT & FLUID HAEMOGLOBIN PHOSPHATE BINDERS

CALCIUM - WHAT IS IT?

Calcium is a mineral which is a major component of bones and teeth. Calcium levels are normally kept in balance by several organs including the kidneys. The blood levels of calcium can rise too high or fall too low when your kidneys are not working. Both a high and low calcium level can lead to bone and joint problems.

NORMAL CALCIUM LEVELS

The local laboratory range is used, Usually 2.25-2.65mmol/l.

REASONS FOR A HIGH CALCIUM LEVEL


* Your phosphate binder tablets need adjusting
* Excess production of parathyroid hormone (Your PTH level will be checked to see if this is the case)
* Indigestion remedies - e.g. Rennies, Settlers and Tums contain calcium - taking these can cause high calcium

REASON FOR A LOW CALCIUM LEVEL

* Vitamin D deficiency - Vitamin D is needed to absorb calcium

You may need an artificial Vitamin D supplement called "Alfacalcidol"

Calcium and phosphate levels are linked and the aim is to try and keep both levels within the suggested ranges to help prevent bone problems.

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GLUCOSE- WHAT IS IT?

A sugar found in the blood. In some people, glucose cannot be used properly and their blood glucose level may increase. This is known as diabetes. A high blood sugar level can cause symptoms of increased thirst, frequent urination, extreme tiredness and weight loss. NORMAL BLOOD SUGAR LEVEL Between 5-7mmol/l. Your doctor may check your blood glucose level when you attend clinic. If you have diabetes your blood glucose levels should be tested regularly. Ask you doctor.

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CHOLESTEROL - WHAT IS IT?

A type of fat in the blood which can gradually build up on the inside of the blood vessels causing a narrowing or blockage.
A high cholesterol level is one of the risk factors for developing heart disease.
If you have a high cholesterol level the dietitian will advise you on any changes you can make in your diet to help.

Sometimes tablets are needed to help reduce cholesterol levels.

NORMAL CHOLESTEROL LEVEL

The local laboratory range is used.
Generally between 2.4-5.2mmol/l.

REASONS FOR A HIGH CHOLESTEROL LEVEL

* Eating too much fat in the diet.
* Being overweight.
* Family history.
* Some types of kidney disease can result in a high cholesterol.

REASONS FOR A LOW CHOLESTEROL LEVEL

* Poor nutritional intake.

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PHOSPHATE - WHAT IS IT?

A mineral which is found in many foods especially dairy foods such as milk, eggs and cheese. It is essential for the formation of healthy bones.
A high phosphate level can lead to itching, red eyes and in the longer term bone disease can develop.
The following are used to try and keep your phosphate and calcium levels within the suggested range-

* Low phosphate diet
* Phosphate binder tablets
* Vitamin D supplements - Alfacalcidol
* If you are on dialysis, changing the calcium content of the dialysis fluid.

PHOSPHATE GUIDELINE

Less than 1.8mmol/l

REASONS FOR A HIGH PHOSPHATE LEVEL

* Eating too many high phosphate foods.
* Forgetting to take the phosphate binder tablets, or taking them at incorrect times.
* The dose of the phosphate binders needs adjusting.

REASONS FOR A LOW PHOSPHATE LEVEL

* Taking too many phosphate binders.
* Poor appetite.

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POTASSIUM - WHAT IS IT?

A mineral found in most foods especially fruit and vegetables. Potassium is needed for healthy muscle and a regular heartbeat. Both a high and low potassium level can lead to changes in heartbeat and in severe cases this can cause the heart to stop.

POTASSIUM GUIDELINE

Between 3.5-5.5mmol/l for those not on dialysis
Between 3.5-5.5mmol/l if you are on peritoneal dialysis
Between 3.5-6.5mmol/l if you are on haemodialysis (pre-dialysis result)

REASONS FOR A HIGH POTASSIUM LEVEL

* Eating foods which are high in potassium
* A recent blood transfusion
* Constipation
* An infection
* Medication - some tablets can increase potassium levels

REASONS FOR A LOW POTASSIUM LEVEL

* Poor appetite
* Diarrhoea
* Diuretics (water tablets)

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UREA - WHAT IS IT?

A waste product from protein foods (meat, fish, eggs, milk, cheese, nuts and pulses). When your kidneys are not working properly the level of urea builds up in the blood. Urea levels vary between individuals so there are no guidelines. It is normal to have a high urea level when your kidneys are not working properly or when you start HD or PD. This may make you feel nauseous and cause an unpleasant taste. UREA & HAEMODIALYSIS Once you are receiving adequate dialysis your urea level will be much lower at the end of your dialysis session because urea is cleared from your blood when you are dialysing. After a few treatments, you should find that any nausea improves and food in more appetising. UREA & PERITONEAL DIALYSIS When you begin PD your urea level will start to fall because some urea is dialysed out with each bag exchange. After a short time on your full regime of PD bag exchanges, you should find that any nausea improves and food is more appetising. Once PD or haemodialysis is established, a sudden drop in your urea level can be an indication that you are not eating enough protein foods.

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ALBUMEN - WHAT IS IT?

A type of protein in the blood. Albumin can help to show how well nourished you are. If you have an infection or a poor appetite your albumin level can fall quickly and it can take at least 3 weeks to return to normal.

NORMAL ALBUMIN LEVEL

The local laboratory range is used.
Over 35g/l is acceptable.

REASONS FOR A LOW ALBUMIN LEVEL

* Not eating enough protein and calories in your diet.
* Recent infection.
* Fluid overload.
PROBLEMS RESULTING FROM A LOW ALBUMIN

* Muscle breakdown/weakness.
* Increased risk of developing infections.
* Oedema (fluid overload, puffy ankles).

Your dietitian will advise you how to increase the protein foods in your diet if this is necessary. 

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PARATHYROID HORMONE - WHAT IS IT?

A hormone produced by the parathyroid glands in the neck.
Parathyroid Hormone (PTH) works with Vitamin D to regulate the levels of calcium and phosphate in the bones and blood.
When the kidneys are not working properly and do not produce enough Vitamin D more PTH is made. A high PTH level prevents calcium from getting into the bones. This means that the bones become thin and weak, causing pain and increasing the risk of fractures.

PTH GUIDELINES

Between 2-3 times the local laboratory range is used.
Usually 130-210pg/ml.

REASONS FOR A HIGH PTH

* Insufficient Vitamin D.
* The parathyroid gland fails to switch off.

REASONS FOR A LOW PTH

* After the parathyroid glands have been removed.
* Too much Alfacaidol/Vitamin D is being taken.

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WEIGHT & FLUID - WHAT IS IT?

INDIVIDUALS NOT ON DIALYSIS 

You will be weighed at each clinic. This will help us to monitor your nutritional status - i.e. if you are gaining or losing weight or if you are retaining fluid.

FLUID

You may have to follow a fluid restriction, but only if this is advised by your doctor.
If you are unsure whether you need to restrict your fluid intake please ask you doctor.

TARGET WEIGHT AND FLUID

HAEMODIALYSIS (HD)

WHAT IS IT?
This is your body weight without any additional fluid. This is the weight you should be at the end of your dialysis session.
When you are weighed before dialysis it is normal to weigh more than your target weight. This is due to the fluids you have drunk between dialysis sessions.

IDEAL PRE-DIALYSIS WEIGHT

Less than 2kg above your target weight - also called dry weight.

REASONS FOR A HIGHER WEIGHT GAIN

* Drinking too much fluid
* Increase in flesh weight, therefore your target weight/dry weight needs adjusting.

PROBLEMS WITH DRINKING TOO MUCH FLUID

* Breathlessness.
* Pulmonary oedema (fluid on the lungs).
* Extra strain on the heart.
* Oedema (puffy ankles).
* Blood pressure can rise.
* Extra time is needed on dialysis.

Keeping to your fluid restriction is very important. If you are unsure what your daily fluid allowance is please ask your doctor.

PERIOTONEAL DIALYSIS (PD)

WHAT IS IT?
This is your body weight without any additional fluid. This is the weight you should be when you weigh yourself in the morning AFTER draining out.
During your PD training you will have been taught how to assess your fluid balance. If you are unsure please ask your PD nurse for advice.

REASONS FOR WEIGHT GAIN

* Drinking too much fluid.
* Increase in flesh weight, your target weight, also called dry weight, needs adjusting.
* Your regime of exchanges needs adjusting - YOUR NURSE WILL ADVISE.

PROBLEMS WITH DRINKING TOO MUCH FLUID

* Breathlessness.
* Pulmonary oedema (fluid on the lungs).
* Extra strain on the heart.
* Oedema (puffy ankles).
* Blood pressure can rise.
* More strong bags are needed.

Keeping to your fluid restriction is very important. If you are unsure what your daily fluid allowance is please ask your doctor.

The information contained in this booklet does not replace the advice of trained health care professionals 

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CREATININE - WHAT IS IT?

A waste product which comes from the normal daily breakdown of muscle. When your kidneys are not working the creatinine level rises in the blood.
The creatinine level varies between individuals and depends largely on body size and the amount of muscle you have. Generally men tend to have a higher level than women.
It is normal to have a higher creatinine level when your kidneys are not working properly or before you start PD. In haemodialysis it is normal to have a higher creatinine level pre-dialysis and this will fall during your dialysis treatment as it is cleared out of your blood.

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HAEMOGLOBIN - WHAT IS IT?

A compound which carries oxygen to the red blood cells and helps to prevent anaemia. Anaemia can be a common problem causing lethargy and breathlessness. Haemoglobin levels are measured regularly to show whether you are anaemic.

HAEMOGLOBIN GUIDELINE

 10 - 12g/dI.

 REASONS FOR A LOW HAEMOGLOBIN LEVEL

 * Lack of eryrthropoeitin or EPO.
When the kidneys are not working properly they do not produce enough EPO.
EPO is needed to make red blood cells.
*Iron deficiency - low ferritin levels.
* Episodes of prolonged bleeding.
*Infection.

You may need regular EPO injections and iron supplements to maintain your haemoglobin level.

 REASONS FOR A HIGH HAEMOGLOBIN LEVEL

 * EPO injections or iron supplements may need to be reduced.
A high haemoglobin level can cause problems with blood clotting. 

 
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PHOSPHATE BINDERS - WHAT ARE THEY?

These are tablets which you may be asked to take to help control your phosphate level.
The following are all phosphate binders-

PHOSPHATE BINDER PRESENTATION TAKING 

Calcichew / Cacium carbonate Tablet Chew
Calcium acetate / Phosex Tablets Swallow whole
Calcium 500/Calcium carbonate Tablets Suck or swallow
Titralac/Calcium carbonate Tablet Suck or swallow
Renegal/Sevelamer Capsule Swallow
Sandocal/Calcium lactate gluconate Effervescent drink Drink
Alucaps/Aluminium hydroxide Capsule Swallow


Most phosphate binders contain calcium, (except Renagel and Alucaps), and will help keep your calcium level in balance, as well as controlling your phosphate level.

The above tablets work by binding some of the phosphate which is in your food, so that it is not absorbed into the blood.

PHOSPHATE BINDERS MUST BE TAKEN
WITH FOOD CONTAINING PHOSPHATE
OTHERWISE THEY WILL NOT WORK EFFECTIVELY

Your dietitian will advise you on the best time to take them - based on what you are eating.

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