What Does A Low Bun Creatinine Ratio Mean?

26.07.2023 0 Comments

What Does A Low Bun Creatinine Ratio Mean
Women and children may have lower BUN levels than men because of how their bodies break down protein. A low BUN-to-creatinine ratio may be caused by a diet low in protein, a severe muscle injury called rhabdomyolysis, pregnancy, cirrhosis, or syndrome of inappropriate antidiuretic hormone secretion (SIADH).

Should I be concerned about a low BUN creatinine ratio?

What does it mean if your BUN/Creatinine Ratio result is too low? A decreased ratio may be observed with liver disease and poor diet. Temporary levels that are high or low may not be a cause for concern and should be retested to confirm. – Liver disease can cause a lower BUN level.

What causes a low bun creatinine ratio?

Clinical Significance – The BUN and s Cr are screening tests of renal function. Because they are handled primarily by glomerular filtration with little or no renal regulation or adaptation in the course of declining renal function, they essentially reflect GFR.

Unfortunately, their relation to GRF is not a straight line but rather a parabolic curve ( Figure 193.3 ). Their values remain within the normal range until more than 50% of renal function is lost. Within that range, however, a doubling of the values (e.g., BUN rising from 8 to 16 mg/dl or s Cr from 0.6 to 1.2 mg/dl) may mean a 50% fall in the GFR.

Therefore, in the early stages of renal disease, these tests could create a false sense of security. Random values above the midrange of normal should be corroborated by a normal c Cr before one can confidently tell a patient that his or her kidney function is normal.

  • At the other end of the curve, small changes in kidney function can produce large increments in BUN and s Cr.
  • Here, these tests are generally adequate to follow a patient’s course.
  • Indeed, the reciprocal of the s Cr plotted against time shows a straight-line progression of renal disease in each individual patient, and can be used to predict the advent of end-stage renal disease.

At all stages of renal insufficiency, the s Cr is a much more reliable indicator of renal function than the BUN because the BUN is far more likely to be affected by dietary and physiologic conditions not related to renal function ( Table 193.1 ). For example patients with congestive heart failure and intact kidneys commonly present with a BUN of 50 to 70 mg/dl and an s Cr below 1.2 mg/dl. With so many limitations on the usefulness of the BUN, one wonders why the test survives. When taken with the s Cr, it is a very useful clue to the presence of a prerenal or postrenal component to azotemia. Other factors being normal, a patient with an s Cr of 5.0 mg/dl would be expected to have a BUN close to 50 mg/dl.

If the BUN is 100 mg/dl instead, then the clinician should begin a search for extrarenal factors ( Table 193.1 ). Note that this 10 to 1 ratio applies best in moderate to advanced renal failure. Attention to these reversible complications of uremia can give a patient a reprieve from an untimely sentence of end-stage renal disease.

LAB VALUE INTERPRETATION BUN AND CREATININE

A low BUN/Cr ratio suggests inadequate protein intake, reduced urea synthesis as in advanced liver disease, supernormal excretion of urea as in sickle cell anemia, increased creatinine production as in rhabdomyolysis, or more effective removal of urea than creatinine during dialysis. where The BUN and creatinine, taken together, are valuable screening tests in evaluating renal disease. Though they may fall short as absolute indicators of renal function at any-given point in time, they are useful in following progression of disease.

Is low BUN level serious?

Interpreting test results – The test report should include a line for BUN that shows the level found in your sample as well as the laboratory’s reference range. BUN is typically reported in milligrams per deciliter of blood (mg/dL). Working with your doctor is the best way to understand the significance of your BUN test.

  • The American Board of Internal Medicine lists a typical reference range for BUN as eight to 20 mg/dL.
  • However, this range is not universal.
  • Labs can use different methods to measure BUN or report BUN in different units, and what constitutes a normal result can vary from lab to lab.
  • If you had a panel test, you should see separate test results for any other measurements taken along with BUN.

Each test component will have the listed reference range for the laboratory that conducted your test. Your doctor can discuss your BUN levels and how they relate to your overall health, symptoms, and other test measurements. This is important because BUN levels alone are not a consistent predictor of kidney function.

Elevated BUN can occur with kidney problems, but it can also happen from eating lots of protein, taking certain medications, or other issues like dehydration or burns. BUN levels often rise with aging as well. Independently, blood urea nitrogen may not reflect kidney function. For this reason, it is often interpreted in the context of other measurements, such as creatinine, a breakdown product of the muscle filtered by the kidneys.

In some cases, the doctor may look at the ratio of BUN to creatinine to help determine the underlying cause of the altered kidney function. Abnormally low BUN levels can signify malnutrition, lack of protein in the diet, and liver disease. Therefore, other tests included in a panel test, like the CMP, may provide helpful information for understanding the significance of low BUN.

Was my BUN level normal or abnormal? Were any other measurements taken along with BUN? What do the test results mean for my kidney function? If my test was abnormal, what is the most likely explanation for that result? Should I repeat the BUN test at any point or have any other follow-up tests?

BMP Blood Test (Basic Metabolic Panel) CMP Blood Test (Comprehensive Metabolic Panel) Creatinine Blood Test eGFR Test (Estimated Glomerular Filtration Rate) Renal Panel Test

What is an alarming bun creatinine ratio?

What do my test results mean? – Test results may vary depending on your age, gender, health history, and other things. Your test results may be different depending on the lab used. They may not mean you have a problem. Ask your healthcare provider what your test results mean for you.

The normal BUN level is between about 7 and 20 milligrams per deciliter (mg/dL). Unless this level is greater than 60 mg/dL, it may not help your healthcare provider measure your kidney health. A better measure is the ratio of BUN to creatinine found in your blood. Typically, the ratio of BUN to creatinine should be between 10:1 and 20:1.

If it’s lower or higher than that, it may mean you have a problem with your kidneys or you may not be drinking enough water.

Does low BUN mean kidney damage?

Jump to Sections –

  1. What Does BUN Mean in a Blood Test?
  2. BUN Normal Range
  3. What Does High BUN Mean?
  4. What Does Low BUN Mean?

BUN levels are a measurement of how much urea has been processed by the kidneys. Urea is a waste product that is excreted in urine. A patient’s high BUN levels may indicate that their kidneys aren’t functioning properly, while lower BUN levels indicate overhydration, liver disease, or malnutrition.

Can dehydration cause low BUN creatinine?

Why It Is Done – These tests are done:

To see if your kidneys are working normally. To find out if your kidney disease is changing. To see how well the kidneys work in people who take medicines that can cause kidney damage. To check for severe dehydration, Dehydration generally causes BUN levels to rise more than creatinine levels. This causes a high BUN-to-creatinine ratio. Kidney disease or blocked urine flow from your kidney causes both BUN and creatinine levels to rise.

How is low BUN and creatinine treated?

How to increase creatinine levels – Gentle exercise to increase muscle mass, or increasing creatine intake in the diet may help, particularly for those on a vegetarian diet who may not be eating enough protein. For people who do high-intensity exercise, creatine as a dietary supplement is generally considered safe.

A range of creatine supplements is available for purchase online, However, the body produces creatine naturally, and most people who eat a balanced diet and are moderately active should not need to supplement their diet. Low creatinine levels can indicate an underlying health problem, such as liver disease, but if this is the case, it will usually present alongside other symptoms.

In these instances, the condition will be best tested by a doctor. More often, low levels of creatinine are a normal part of aging or a temporary issue that can be resolved with changes to diet.

How do I improve my bun creatinine ratio?

Treatment Options – There are various treatment options available for managing high bun/creatinine ratio, depending on the underlying cause and severity of the condition. Some of the common treatment options include:

Dietary Changes: One of the primary ways to manage high bun/creatinine ratio is by making dietary changes. This may include reducing the intake of protein-rich foods, such as meat, poultry, and dairy products. Instead, you may be advised to consume more fruits, vegetables, and whole grains, which are low in protein. Medications: Depending on the underlying cause of the high bun/creatinine ratio, your healthcare provider may prescribe medications to help manage the condition. For instance, if the high ratio is due to dehydration, you may be given intravenous fluids to rehydrate your body. Similarly, medications like diuretics may be prescribed to help remove excess fluid from the body. Lifestyle Changes: In addition to dietary changes, you may also be advised to make certain lifestyle changes to help manage high bun/creatinine ratio. For instance, you may be advised to quit smoking, limit alcohol intake, and exercise regularly. Dialysis: In some cases, if the high bun/creatinine ratio is severe and cannot be managed through other treatment options, your healthcare provider may recommend dialysis. This is a medical procedure that helps remove waste products and excess fluid from the blood when the kidneys are unable to perform their function properly.

A high Bun/Creatinine Ratio can indicate several things including dehydration, kidney disease, or damage to the muscles. It is important to discuss with a healthcare provider to determine the underlying cause.

When should I be worried about low creatinine levels?

Extreme weight loss – Weight loss can result in the reduction of muscle mass, leading to low levels of creatinine. During pregnancy, blood flow to the kidneys is higher. This increases a person’s GFR and the rate of creatinine excretion. Due to this, pregnant people typically have lower levels of blood creatinine.

  1. A 2020 review found that the mean blood creatinine level in pregnant people is 77–84% of that in nonpregnant people.
  2. A person’s creatinine levels will also change across trimesters.
  3. Low creatinine levels mean something is affecting creatine production in the body.
  4. This will often result from a person having low muscle mass or body weight.
You might be interested:  What Does Rollback Mean At Walmart?

However, low creatinine levels may also indicate a person has chronic kidney disease, reduced kidney function, or malnutrition. Learn more about low creatinine levels here. High creatinine levels may also indicate severe kidney problems, such as infection or failure.

  1. However, this will not always be the case.
  2. Antibiotics, diet, and dehydration from exercise can all impact creatine production.
  3. In these instances, creatinine levels may return to normal shortly after a person addresses the underlying cause.
  4. Learn more about high creatinine levels here.
  5. Dietary choices and physical activity play an essential role in regulating blood creatinine levels.

It is advisable to keep protein consumption within the recommended range for age and activity level. Creatinine levels outside of normal ranges may indicate an underlying condition. If a doctor can diagnose what may be causing abnormal creatinine levels, they can suggest suitable treatment options.

  1. If levels persist at an abnormally high or low level, people may need to see a kidney specialist.
  2. Early treatment of rising or falling creatinine levels is essential to prevent more significant kidney disease.
  3. The body produces creatinine at a steady rate, and measuring the levels only requires a routine blood sample.

Measuring creatinine levels is a useful way to identify the GFR, an indicator of overall kidney function. Doctors can use GFR levels to check for signs of chronic kidney disease. A doctor or healthcare professional will carry out the blood test. Before the test, they might ask questions related to:

dietphysical activitysupplementscurrent medications

It is best to discuss any medical conditions and any family history of kidney disease at the time of the blood test. There is no need to avoid food or drink before the blood test. The blood test involves collecting blood from a vein in the arm or hand.

  • The doctor then sends the sample to a lab for analysis.
  • Adult males’ average creatinine level range is 60–110 μmol/L, while it is 45–90 μmol/L for females.
  • Creatinine is the waste product of creatine, which the body uses for energy.
  • Doctors can use creatinine level tests to check for abnormalities in kidney function.

Dehydration, exercise, physical changes in pregnancy, and kidney failure can all impact creatinine levels. A person will typically undergo creatinine level tests in a medical setting, meaning doctors will usually be able to quickly interpret results and plan the next steps.

Is low BUN common?

What does low blood urea nitrogen mean? – Low BUN levels aren’t common. However, you may have low BUN levels from the following:

Low-protein diet. Small body type. Overhydration (too much water in your body). Liver disease,

Why is BUN low in liver disease?

Causes of Decreased BUN – BUN is decreased by decreased production (i.e., hepatic insufficiency, dietary protein restriction) or increased excretion (i.e., polyuric conditions, overhydration, late pregnancy). Decreased BUN may be an indication for hepatic function tests (see Chapter 9 ).

Is a low BUN better than a high BUN?

Hair Bun 101: How To Choose The Right Hair Bun For Your Face Shape Be it a clean top knot or a soft messy one, hair buns have evolved as the go-to hairstyle for most girls for literally any occasion! Hair buns not only look good on most people, they are also pretty versatile and work for most occasions. A round face has fuller cheeks and a round jaw line. It forms a circular frame with equal face length and width. While picking a hair bun, go for a high messy bun with layers to add volume to your hair. It will even out the roundness and make your face look slimmer.

How important is bun creatinine ratio?

NEW YORK DOH APPROVED: YES CPT Code: 82565, 84520 Order Code: 2968 ABN Requirement: No Includes: Blood Urea Nitrogen (BUN), Serum Creatinine, BUN/Creatinine Ratio, Estimated Glomerular Filtration Rate (eGFR) Specimen : Serum Volume : 1.0 mL Minimum Volume : 0.5 mL Container: Gel-barrier tube (SST, Tiger Top) Collection :

Collect and label sample according to standard protocols. Gently invert tube 5 times immediately after draw. DO NOT SHAKE. Allow blood to clot 30 minutes. Centrifuge for 10 minutes.

Fasting: Fasting is not required Transport: Store serum at 2°C to 8°C after collection and ship the same day per packaging instructions included with the provided shipping box. Stability: Ambient (15-25°C): 7 days Refrigerated (2-8°C): 7 days Frozen (-20°C): 3 months Causes for Rejection : Specimens other than serum; improper labeling; samples not stored properly; samples older than stability limits Methodology : Photometric Assay, Calculation Turn Around Time: 1 to 3 days Reference Range :

Analyte Male Female
BUN, 0-18 Years 5-18 mg/dL 5-18 mg/dL
BUN, ≥19 Years 8-23 mg/dL 8-23 mg/dL
Creatinine, ≤2 Days 0.79-1.58 mg/dL 0.79-1.58 mg/dL
Creatinine, 3-27 Days 0.35-1.23 mg/dL 0.35-1.23 mg/dL
Creatinine, 1 Month- 9 Years 0.20-0.73 mg/dL 0.20-0.73 mg/dL
Creatinine, 10-12 Years 0.30-0.78 mg/dL 0.30-0.78 mg/dL
Creatinine, 13-15 Years 0.40-1.05 mg/dL 0.40-1.00 mg/dL
Creatinine, 16-17 Years 0.60-1.20 mg/dL 0.50-1.00 mg/dL
Creatinine, 18-29 Years 0.60-1.24 mg/dL 0.50-0.96 mg/dL
Creatinine, 30-39 Years 0.60-1.26 mg/dL 0.50-0.97 mg/dL
Creatinine, 40-49 Years 0.60-1.29 mg/dL 0.50-0.99 mg/dL
Creatinine, 50-59 Years 0.70-1.30 mg/dL 0.50-1.03 mg/dL
Creatinine, 60-69 Years 0.70-1.35 mg/dL 0.50-1.05 mg/dL
Creatinine, 70-79 Years 0.70-1.28 mg/dL 0.60-1.00 mg/dL
Creatinine, ≥80 Years 0.70-1.22 mg/dL 0.60-0.95 mg/dL
BUN/Creatinine Ratio 6-22 6-22

The eGFR is based on the CKD-EPI 2021 equation. To calculate the new eGFR from a previous Creatinine or Cystatin C result, go to https://www.kidney.org/professionals/kdogi/gfr%5Fcalculator, Please Note: If results for BUN and Creatinine are both within the normal reference range, the BUN/Creatinine ratio will not be reported (not applicable).

  • Clinical Significance: The BUN/Creatinine ratio is useful in the differential diagnosis of acute or chronic renal disease.
  • Reduced renal perfusion, e.g.
  • Congestive heart failure or recent onset of urinary tract obstruction, will result in an increase in BUN/Creatinine ratio.
  • Increased urea formation also results in an increase in the ratio, e.g.

gastrointestinal bleeding, trauma, etc. When there is decreased formation of urea, as seen in liver disease, there is a decrease in the BUN/Creatinine ratio. In most cases of chronic renal disease, the ratio remains relatively normal. The CPT codes provided are based on AMA guidelines and are for informational purposes only.

What level of BUN creatinine indicates kidney failure?

Blood Urea Nitrogen (also called BUN) – Blood carries protein to cells throughout the body. After the cells use the protein, the remaining waste product is returned to the blood as urea nitrogen. Healthy kidneys take urea nitrogen out of the blood and remove it through the urine.

What level of BUN indicates kidney failure?

What is the BUN level for kidney failure? – A level surpassing the BUN normal range of 6-20 mg/dL indicates kidney problems. If your BUN test shows extreme results, it might signal kidney failure. For example, a BUN level of 75 mg/dL is highly considered alarming.

Is it bad to have low creatinine?

Low values –

Low blood creatinine levels can mean lower muscle mass caused by a disease, such as muscular dystrophy, or by aging. Low levels can also mean some types of severe liver disease or a diet very low in protein. Pregnancy can also cause low levels. Low creatinine clearance levels can mean you have chronic kidney disease or serious kidney damage. Kidney damage can be from conditions such as a life-threatening infection, shock, cancer, low blood flow to the kidneys, or urinary tract blockage. Other conditions, such as heart failure and dehydration, can also cause low clearance levels. Low BUN-to-creatinine ratios may be linked with a diet low in protein, a severe muscle injury called rhabdomyolysis, pregnancy, cirrhosis, or syndrome of inappropriate antidiuretic hormone secretion (SIADH). SIADH sometimes occurs with lung disease, cancer, diseases of the central nervous system, or the use of certain medicines.

Can exercise increase BUN levels?

Abstract – Examination of 19 serum biochemical and hematologic parameters in a group of white male runners, ranging in age from 23 to 47 years, just prior to and immediately after a 13-mile “mini-marathon,” demonstrated a significant increase, by paired Student t-test, in mean values of: K+, BUN, creatinine, CK, LDH, AST (SGOT), alkaline phosphatase, bilirubin, uric acid and leukocyte counts.

Prevailing environmental conditions were such as to produce no significant hemoconcentration. Using this group’s statistics and this hospital laboratory’s upper limits of normal, the percentage of values above two SDs are, for the resting state: K+ 7%, BUN 7%, creatinine 0%, CK 21%, LDH 21%, AST 0%, alkaline phosphatase 0%, bilirubin 7%, uric acid 7%, and leukocyte count 0%.

Post-exertional values above normal limits are: K+ 7%, BUN 21%, creatinine 21%, CK 93%, LDH 86%, AST 0%, alkaline phosphatase 0%, bilirubin 14%, uric acid 36%, and leukocyte 71%. Consequently, abnormally high values for K+, BUN, creatinine, CK, LDH, bilirubin, uric acid, and leukocyte counts can often be expected in some patients who exercise heavily.

Can kidney stones cause low BUN?

A blockage in the urinary tract (such as a kidney stone) can cause a high BUN-to-creatinine ratio. A very high BUN-to-creatinine ratio may be caused by bleeding in the digestive tract or respiratory tract. A low BUN value may be caused by a diet very low in protein, malnutrition, or severe liver damage.

Does drinking water lower creatinine?

While no specific food or supplement can single-handedly improve kidney function or creatinine levels, Kidney Kitchen® contributor, Dr. Blake aka “The Cooking Doc®,” explains what factors can affect those readings – and tips to potentially improve them! What are your biggest goals as a person living with kidney disease or as a family member of someone with kidney disease? If you are not at the stage of kidney disease that requires dialysis, you and I probably have similar aims: (1) find a way to improve or maintain kidney function and (2) delay or avoid dialysis.

Now, imagine that there was a magical superfood, a cleansing detox tea or an all-natural supplement that could do this. It is easy to be convinced that such a product exists. Many websites claim that specific foods or supplements can prevent people from needing dialysis by improving their creatinine levels and their eGFRs ( estimated glomerular filtration rate ).

These are two of the most common measures of kidney function and they are usually (but not always) interpreted like this: lower creatinine levels and higher eGFRs mean better kidney function. I have heard many stories of people, some of them patients that I care for in my office, spending money on pills and foods with the hope that they will cure their kidney disease or keep them off dialysis.

  1. And if a supplement like this did exist, I’d be shouting about it from my office rooftop and encouraging all my patients to start taking it.
  2. Unfortunately, there is no such thing.
  3. Because of the complicated way in which kidneys lose their ability to function, it is just not realistic to expect individual foods — such as cabbage, cauliflower or red pepper — or supplements (like nettle tea) to reverse the scarring caused by 20 to 30 years of conditions like diabetes and vascular disease (disease of the arteries, veins and lymph vessels or blood disorders).

It just cannot happen. On the other hand, while no specific food or supplement can single-handedly improve kidney function or creatinine levels, there are a few factors that can affect creatinine readings in blood tests. Here are the most common ones:

Creatine supplements : Creatine supplements can increase creatinine levels. Medicines : Certain medicines can increase creatinine levels. Meat consumption : Eating a large amount of meat can briefly increase creatinine levels for 6-12 hours. Water intake : Drinking a lot of water just before a blood test can temporarily lower creatinine levels.

Even though these factors can change the blood test results, they do not have a lasting impact on kidney function. These effects only last a few hours, or a couple of days at most, and do not improve or worsen kidney function. Improving or maintaining kidney health requires adopting a kidney-healthy food and fluid plan rather than relying on individual “superfoods” or supplements. I recommend:

Reducing animal protein : Limiting the consumption of animal protein may lessen the burden on the kidneys and promote better overall kidney health. Lowering sodium (or salt) : Minimizing salty foods helps maintain proper fluid balance and blood pressure. Limiting sugary beverages : High intake of sugary drinks can contribute to diabetes and obesity, which are risk factors for kidney disease. Controlling diabetes : Managing diabetes through a balanced food and fluid plan and medicines plays a crucial role in maintaining kidney function. Eating more fruits and vegetables : Eating more fruits and vegetables can help you decrease body weight and blood pressure, as well as maintain a healthy acid-base balance, benefiting kidney health. Practicing home cooking : Preparing meals at home allows better control over ingredients, reducing the amount of unhealthy additives and extra sodium.

When it comes to kidney health, there is no magical food or quick fix. Rather than wasting your money on an internet product that is unlikely to give you any benefit, focus on adopting a consistent kidney-healthy food and fluid plan that includes less animal protein, more fruits and vegetables, reduced sodium, controlled diabetes and home-cooked meals.

Can overhydration cause low creatinine?

March 5, 1996 R.K. Skogerboe, Ph.D. Director of Biomonitoring Corning Clinical Laboratories 363 West Drake Road, Suite 8 Fort Collins, CO 80526 Dear Dr. Skogerboe: This is in response to your letter of February 29, regarding your questions about low urinary creatinine levels.

In general, in order for urine samples to be acceptable for analyses for cadmium in urine, (CdU) and Beta-2 microglobulin in urine (Beta-M), urine samples should be screened, by simple methods, prior to submitting the urine sample to the laboratory for more costly analyses. If a urine sample is too dilute (specific gravity less than 1.008) or too acidic (pH less than 5.5), another sample should be collected for analysis.

Regarding your clients’ questions about low urinary creatinine levels (CRTU), OSHA specified a number of sample collection and handling procedures in Appendix F of the final cadmium standard to reduce the chance that Beta-M will degrade. Under Section 3.4.1, for example, employees are advised to void, drink a large glass of water, and then provide a urine specimen for analysis within an hour (29 CFR 42424).

OSHA is of the opinion that, when standardizing urine samples to grams of CRTU, many of the low creatinine levels result from over-hydration. OSHA recommends that employees provide a urine sample for CdU, Beta-M, and CRTU analyses without first drinking a glass of water. If that urine sample is too dilute (specific gravity less than 1.008), another sample should be collected at the next void with no intervening hydration.

If the urine is too acidic (pH less than 5.5), the employee should drink no more than an 8-ounce glass of water; another sample should be collected after 1 hour; urine from that second void should be used for CdU, Beta-M, and CRTU analyses. Samples that are too dilute or too acidic should not be submitted for urinalysis.

If low CRTU levels persist, further evaluation of renal function is warranted to rule out other etiologies. If you have any questions, please contact my office at 202 219-5003. Sincerely, Melissa DcDiarmid, MD, MPH USDOL/OSHA Office of Occupational Medicine 200 Constitution Avenue, NW. Washington, DC 20210 Corning Clinical Laboratories Biomonitoring Laboratory 363 West Drake Road, Suite 8 Fort Collins, CO 80526 February 29, 1996 Ms.

Caroline Freeman Office Director Health Standards Program Room N3718, USDOL-OSHA 200 Constitution Avenue, NW. Washington, DC 20210 Dear Ms. Freeman, Per our phone discussion of this date, I am writing to explain a problem associated with testing urine for Cadmium and Beta-2-Microglobulin and to request the advice of your office in ameliorating this problem.

As you are aware, a significant percentage of urine specimens received exhibit abnormally low creatinine concentrations while the Cd or B-2-M levels are typically within normal ranges in terms of non-normalized concentrations. However, normalization to creatinine often results in ”artificially” elevated velure that exceed the defined cutoffs.

Many of our clients react by entering notations in the patients’ file and retest within 2 weeks. In our experience, all of the retests have produced values within the acceptable ranges. As I told you, this problem is particularly operative for women. Our analysis indicates that nominally 28% of the women and 5% of the men exhibit levels below 0.3 gm/L.

Our clients frequently request advice on approaches for screening urine specimens with low creatinine levels to avoid submitting “abnormal” samples and to preclude the need for retesting. We cannot respond without OSHA approval. Data that we have developed indicate that creatinine levels can be correlated to urine specific gravity and that the correlation coefficient is 0.88.

This suggests that using specific gravity to screen potentially “abnormal” specimens is probably a viable approach. If there is a screening approach acceptable to your office, we would appreciate receiving formal notification to that effect together with any specific criteria and/or operational details.

What causes low creatinine levels in adults?

The two sides of creatinine: both as bad as each other? Acute and chronic kidney diseases are major public health problems, and even relatively small rises in serum creatinine have been found to be associated with an increased risk of morbidity and mortality (-). In contrast, the relevance of serum creatinine levels below the normal range is appreciated far less in clinical practice. A recent paper published in Critical Care Medicine alluded to the fact that a low serum creatinine is an important risk factor for poor outcome (). Using the Australian and New Zealand Intensive Care Society Centre for Outcome and Resource Evaluation database, Udy et al, retrospectively analyzed the data of >1 million adult patients admitted to ICU between 2000–2013 and evaluated the association between peak serum creatinine concentration in the first 24 hours of ICU admission and hospital mortality (). Patients on chronic dialysis, re-admissions, and renal transplant recipients were excluded. The key findings were:

A peak serum creatinine concentration <60 µmol/L in the first 24 hours after ICU admission was independently associated with an increased risk of mortality; In patients with a serum creatinine 180 µmol/L.

These findings were consistent across medical, surgical, trauma and infection-related admission types and independent of gender, age, and admission year. Weight and height data to calculate the body mass index (BMI) were available for 9% of patients, and analysis of this cohort showed that the relationship between low serum creatinine and hospital mortality was consistent across all BMI categories. Although neither the aetiology of low creatinine levels nor the causes of death were available, these results may have very important repercussions for clinical practice. Firstly, the paper serves as a reminder that serum creatinine is more than a marker of renal function. Creatinine is a metabolite of creatine and as such a by-product of muscle metabolism. Creatine is initially synthesized from the amino acids glycine and arginine in liver and kidneys and then transported to the skeletal muscle cells. A proportion of creatine also stems from dietary meat intake. Following conversion to phosphocreatine, it serves as a rapidly mobilizable reserve of high-energy phosphates in muscle. The total amount of creatinine generated from creatine is determined by muscle function, meat intake and de novo generation of creatine. In health, creatinine is produced at a constant rate, but rapid, substantial and sustained falls in production have been demonstrated during critical illness. Therefore, the concentration of creatinine measured in the serum represents the balance between creatinine production and creatinine clearance. Because creatinine is freely filtered across the glomerulus and is neither reabsorbed nor metabolized by the kidney (although tubular secretion does occur), it serves as a marker of renal function in clinical practice. However, serum creatinine has important limitations: it can take 24–36 hours to rise after a definite renal insult, it may overestimate renal function as a result of secretion in the proximal tubule and it can increase following administration of medications that inhibit tubular secretion despite no change in renal function. In addition, creatinine is distributed in total body water and measured as a concentration and may, therefore, be affected by variations in volume status. The causes of a low serum creatinine concentration are generally well known and include reduced muscle bulk, liver disease, significant fluid overload and poor nutritional status but also augmented renal clearance as seen in pregnancy. Although previous studies have described the association of increased mortality with lower creatinine levels in patients on chronic dialysis, in those commencing renal support in the ICU and in older patients (-), the implications of a low serum creatinine in critically ill patients are less well known. The study by Udy et al, with data of >1 million patients is undoubtedly the largest in the literature. Cartin-Ceba et al, previously performed a retrospective analysis of 11,291 critically ill patients admitted to three ICUs over a 47-month period and like Udy et al, showed that both a high and low serum creatinine were risk factors for poor outcome (). A low baseline serum creatinine was independently associated with increased hospital mortality in a concentration-dependent fashion. Adjusted stay in ICU was also longer in this cohort. The question is what mechanisms could underlie these observations. The studies by Udy et al, and Cartin-Ceba et al, do not provide any definitive mechanistic insights (,). Without detailed data about the underlying causes, it is certainly possible that a low serum creatinine was simply an indicator of underlying chronic liver disease, reduced muscle mass, and poor nutritional state. Both studies focused on creatinine concentrations in the first 24 hours of ICU admission. One potential explanation given by the authors is that the results may have been confounded by chronic fluid overload or excessive fluid administration pre-ICU. It is likely that the relationship between low serum creatinine levels and mortality is more complex than assumed at first glance. For instance, serum creatinine can overestimate renal function, and a proportion of patients with a serum creatinine level below the normal range may have had significantly impaired renal function. Udy et al, also showed that the adjusted hospital mortality of patients with a serum creatinine <50 µmol/L in the first 24 hours of admission increased with rising admission albumin levels and was highest in those with a plasma albumin ≥45 g/L (). The authors argue that a low serum creatinine in the setting of adequate albumin levels may imply marked physical deconditioning or muscle wasting (,). Although this is possible, it remains unproven. Using a large database, the authors obviously were unable to provide data on detailed muscle function. Instead, they analyzed the impact of serum creatinine in different BMI groups and showed that the association between low serum creatinine and mortality was independent of BMI. However, BMI is a poor marker of muscle mass (). What are the practical implications of these results? With data of >1 million ICU patients from an ethnically diverse population, the study by Udy et al, has external validity. Clearly, further studies are needed, especially to provide mechanistic insights that could lead to potential therapeutic interventions. In the meantime, the presence of a low baseline serum creatinine level should alert clinicians to the high-risk potential of individual patients. Interestingly, the APACHE II score includes a low creatinine value as a risk factor and assigns two points to the severity score if the most extreme serum creatinine level during the first 24 hours is <0.6 mg/dL (53 µmol/L). However, other risk prediction scores like the Simplified Acute Physiology Score II and Sequential Organ Failure Assessment (SOFA) score do not take into account low creatinine levels. We already know that high creatinine levels are associated with poor outcomes, and now we know that low levels may be just as bad whatever the exact cause. Provenance: This is an invited Commentary commissioned by the Section Editor Zhongheng Zhang (Department of Critical Care Medicine, Jinhua Municipal Central Hospital, Jinhua Hospital of Zhejiang University, Jinhua, China). Conflicts of Interest: The authors have no conflicts of interest to declare.1. Hoste EA, Bagshaw SM, Bellomo R, et al. Epidemiology of acute kidney injury in critically ill patients: the multinational AKI-EPI study. Intensive Care Med 2015; 41 :1411-23.10.1007/s00134-015-3934-7 2. Mehta RL, Cerdá J, Burdmann EA, et al. International Society of Nephrology's 0by25 initiative for acute kidney injury (zero preventable deaths by 2025): a human rights case for nephrology. Lancet 2015; 385 :2616-43.10.1016/S0140-6736(15)60126-X 3. Lewington AJ, Cerdá J, Mehta RL. Raising awareness of acute kidney injury: a global perspective of a silent killer. Kidney Int 2013; 84 :457-67.10.1038/ki.2013.153 4. Lassnigg A, Schmidlin D, Mouhieddine M, et al. Minimal changes of serum creatinine predict prognosis in patients after cardiothoracic surgery: a prospective cohort study. J Am Soc Nephrol 2004; 15 :1597-605.10.1097/01.ASN.0000130340.93930.DD 5. Udy AA, Scheinkestel C, Pilcher D, et al. The Association Between Low Admission Peak Plasma Creatinine Concentration and In-Hospital Mortality in Patients Admitted to Intensive Care in Australia and New Zealand. Crit Care Med 2016; 44 :73-82.10.1097/CCM.0000000000001348 6. Kakiya R, Shoji T, Tsujimoto Y, et al. Body fat mass and lean mass as predictors of survival in hemodialysis patients. Kidney Int 2006; 70 :549-56.10.1038/sj.ki.5000331 7. Smith GL, Shlipak MG, Havranek EP, et al. Serum urea nitrogen, creatinine, and estimators of renal function: mortality in older patients with cardiovascular disease. Arch Intern Med 2006; 166 :1134-42.10.1001/archinte.166.10.1134 8. Barton IK, Hilton PJ, Taub NA, et al. Acute renal failure treated by haemofiltration: factors affecting outcome. Q J Med 1993; 86 :81-90.9. Forni LG, Wright DA, Hilton PJ, et al. Prognostic stratification in acute renal failure. Arch Intern Med 1996;156:1023, 1027.10. Cartin-Ceba R, Afessa B, Gajic O. Low baseline serum creatinine concentration predicts mortality in critically ill patients independent of body mass index. Crit Care Med 2007; 35 :2420-3.10.1097/01.CCM.0000281856.78526.F4 11. Thongprayoon C, Cheungpasitporn W, Kashani K. Serum creatinine level, a surrogate of muscle mass, predicts mortality in critically ill patients. J Thorac Dis 2016; 8 :E305-11.10.21037/jtd.2016.03.62 : The two sides of creatinine: both as bad as each other?

What level of BUN creatinine indicates kidney failure?

Blood Urea Nitrogen (also called BUN) – Blood carries protein to cells throughout the body. After the cells use the protein, the remaining waste product is returned to the blood as urea nitrogen. Healthy kidneys take urea nitrogen out of the blood and remove it through the urine.

Can you improve bun creatinine ratio?

Treatment Options – There are various treatment options available for managing high bun/creatinine ratio, depending on the underlying cause and severity of the condition. Some of the common treatment options include:

Dietary Changes: One of the primary ways to manage high bun/creatinine ratio is by making dietary changes. This may include reducing the intake of protein-rich foods, such as meat, poultry, and dairy products. Instead, you may be advised to consume more fruits, vegetables, and whole grains, which are low in protein. Medications: Depending on the underlying cause of the high bun/creatinine ratio, your healthcare provider may prescribe medications to help manage the condition. For instance, if the high ratio is due to dehydration, you may be given intravenous fluids to rehydrate your body. Similarly, medications like diuretics may be prescribed to help remove excess fluid from the body. Lifestyle Changes: In addition to dietary changes, you may also be advised to make certain lifestyle changes to help manage high bun/creatinine ratio. For instance, you may be advised to quit smoking, limit alcohol intake, and exercise regularly. Dialysis: In some cases, if the high bun/creatinine ratio is severe and cannot be managed through other treatment options, your healthcare provider may recommend dialysis. This is a medical procedure that helps remove waste products and excess fluid from the blood when the kidneys are unable to perform their function properly.

A high Bun/Creatinine Ratio can indicate several things including dehydration, kidney disease, or damage to the muscles. It is important to discuss with a healthcare provider to determine the underlying cause.

What level of BUN indicates kidney failure?

What is the BUN level for kidney failure? – A level surpassing the BUN normal range of 6-20 mg/dL indicates kidney problems. If your BUN test shows extreme results, it might signal kidney failure. For example, a BUN level of 75 mg/dL is highly considered alarming.

What causes low creatinine levels in adults?

The two sides of creatinine: both as bad as each other? Acute and chronic kidney diseases are major public health problems, and even relatively small rises in serum creatinine have been found to be associated with an increased risk of morbidity and mortality (-). In contrast, the relevance of serum creatinine levels below the normal range is appreciated far less in clinical practice. A recent paper published in Critical Care Medicine alluded to the fact that a low serum creatinine is an important risk factor for poor outcome (). Using the Australian and New Zealand Intensive Care Society Centre for Outcome and Resource Evaluation database, Udy et al, retrospectively analyzed the data of >1 million adult patients admitted to ICU between 2000–2013 and evaluated the association between peak serum creatinine concentration in the first 24 hours of ICU admission and hospital mortality (). Patients on chronic dialysis, re-admissions, and renal transplant recipients were excluded. The key findings were:

A peak serum creatinine concentration <60 µmol/L in the first 24 hours after ICU admission was independently associated with an increased risk of mortality; In patients with a serum creatinine 180 µmol/L.

These findings were consistent across medical, surgical, trauma and infection-related admission types and independent of gender, age, and admission year. Weight and height data to calculate the body mass index (BMI) were available for 9% of patients, and analysis of this cohort showed that the relationship between low serum creatinine and hospital mortality was consistent across all BMI categories. Although neither the aetiology of low creatinine levels nor the causes of death were available, these results may have very important repercussions for clinical practice. Firstly, the paper serves as a reminder that serum creatinine is more than a marker of renal function. Creatinine is a metabolite of creatine and as such a by-product of muscle metabolism. Creatine is initially synthesized from the amino acids glycine and arginine in liver and kidneys and then transported to the skeletal muscle cells. A proportion of creatine also stems from dietary meat intake. Following conversion to phosphocreatine, it serves as a rapidly mobilizable reserve of high-energy phosphates in muscle. The total amount of creatinine generated from creatine is determined by muscle function, meat intake and de novo generation of creatine. In health, creatinine is produced at a constant rate, but rapid, substantial and sustained falls in production have been demonstrated during critical illness. Therefore, the concentration of creatinine measured in the serum represents the balance between creatinine production and creatinine clearance. Because creatinine is freely filtered across the glomerulus and is neither reabsorbed nor metabolized by the kidney (although tubular secretion does occur), it serves as a marker of renal function in clinical practice. However, serum creatinine has important limitations: it can take 24–36 hours to rise after a definite renal insult, it may overestimate renal function as a result of secretion in the proximal tubule and it can increase following administration of medications that inhibit tubular secretion despite no change in renal function. In addition, creatinine is distributed in total body water and measured as a concentration and may, therefore, be affected by variations in volume status. The causes of a low serum creatinine concentration are generally well known and include reduced muscle bulk, liver disease, significant fluid overload and poor nutritional status but also augmented renal clearance as seen in pregnancy. Although previous studies have described the association of increased mortality with lower creatinine levels in patients on chronic dialysis, in those commencing renal support in the ICU and in older patients (-), the implications of a low serum creatinine in critically ill patients are less well known. The study by Udy et al, with data of >1 million patients is undoubtedly the largest in the literature. Cartin-Ceba et al, previously performed a retrospective analysis of 11,291 critically ill patients admitted to three ICUs over a 47-month period and like Udy et al, showed that both a high and low serum creatinine were risk factors for poor outcome (). A low baseline serum creatinine was independently associated with increased hospital mortality in a concentration-dependent fashion. Adjusted stay in ICU was also longer in this cohort. The question is what mechanisms could underlie these observations. The studies by Udy et al, and Cartin-Ceba et al, do not provide any definitive mechanistic insights (,). Without detailed data about the underlying causes, it is certainly possible that a low serum creatinine was simply an indicator of underlying chronic liver disease, reduced muscle mass, and poor nutritional state. Both studies focused on creatinine concentrations in the first 24 hours of ICU admission. One potential explanation given by the authors is that the results may have been confounded by chronic fluid overload or excessive fluid administration pre-ICU. It is likely that the relationship between low serum creatinine levels and mortality is more complex than assumed at first glance. For instance, serum creatinine can overestimate renal function, and a proportion of patients with a serum creatinine level below the normal range may have had significantly impaired renal function. Udy et al, also showed that the adjusted hospital mortality of patients with a serum creatinine <50 µmol/L in the first 24 hours of admission increased with rising admission albumin levels and was highest in those with a plasma albumin ≥45 g/L (). The authors argue that a low serum creatinine in the setting of adequate albumin levels may imply marked physical deconditioning or muscle wasting (,). Although this is possible, it remains unproven. Using a large database, the authors obviously were unable to provide data on detailed muscle function. Instead, they analyzed the impact of serum creatinine in different BMI groups and showed that the association between low serum creatinine and mortality was independent of BMI. However, BMI is a poor marker of muscle mass (). What are the practical implications of these results? With data of >1 million ICU patients from an ethnically diverse population, the study by Udy et al, has external validity. Clearly, further studies are needed, especially to provide mechanistic insights that could lead to potential therapeutic interventions. In the meantime, the presence of a low baseline serum creatinine level should alert clinicians to the high-risk potential of individual patients. Interestingly, the APACHE II score includes a low creatinine value as a risk factor and assigns two points to the severity score if the most extreme serum creatinine level during the first 24 hours is <0.6 mg/dL (53 µmol/L). However, other risk prediction scores like the Simplified Acute Physiology Score II and Sequential Organ Failure Assessment (SOFA) score do not take into account low creatinine levels. We already know that high creatinine levels are associated with poor outcomes, and now we know that low levels may be just as bad whatever the exact cause. Provenance: This is an invited Commentary commissioned by the Section Editor Zhongheng Zhang (Department of Critical Care Medicine, Jinhua Municipal Central Hospital, Jinhua Hospital of Zhejiang University, Jinhua, China). Conflicts of Interest: The authors have no conflicts of interest to declare.1. Hoste EA, Bagshaw SM, Bellomo R, et al. Epidemiology of acute kidney injury in critically ill patients: the multinational AKI-EPI study. Intensive Care Med 2015; 41 :1411-23.10.1007/s00134-015-3934-7 2. Mehta RL, Cerdá J, Burdmann EA, et al. International Society of Nephrology's 0by25 initiative for acute kidney injury (zero preventable deaths by 2025): a human rights case for nephrology. Lancet 2015; 385 :2616-43.10.1016/S0140-6736(15)60126-X 3. Lewington AJ, Cerdá J, Mehta RL. Raising awareness of acute kidney injury: a global perspective of a silent killer. Kidney Int 2013; 84 :457-67.10.1038/ki.2013.153 4. Lassnigg A, Schmidlin D, Mouhieddine M, et al. Minimal changes of serum creatinine predict prognosis in patients after cardiothoracic surgery: a prospective cohort study. J Am Soc Nephrol 2004; 15 :1597-605.10.1097/01.ASN.0000130340.93930.DD 5. Udy AA, Scheinkestel C, Pilcher D, et al. The Association Between Low Admission Peak Plasma Creatinine Concentration and In-Hospital Mortality in Patients Admitted to Intensive Care in Australia and New Zealand. Crit Care Med 2016; 44 :73-82.10.1097/CCM.0000000000001348 6. Kakiya R, Shoji T, Tsujimoto Y, et al. Body fat mass and lean mass as predictors of survival in hemodialysis patients. Kidney Int 2006; 70 :549-56.10.1038/sj.ki.5000331 7. Smith GL, Shlipak MG, Havranek EP, et al. Serum urea nitrogen, creatinine, and estimators of renal function: mortality in older patients with cardiovascular disease. Arch Intern Med 2006; 166 :1134-42.10.1001/archinte.166.10.1134 8. Barton IK, Hilton PJ, Taub NA, et al. Acute renal failure treated by haemofiltration: factors affecting outcome. Q J Med 1993; 86 :81-90.9. Forni LG, Wright DA, Hilton PJ, et al. Prognostic stratification in acute renal failure. Arch Intern Med 1996;156:1023, 1027.10. Cartin-Ceba R, Afessa B, Gajic O. Low baseline serum creatinine concentration predicts mortality in critically ill patients independent of body mass index. Crit Care Med 2007; 35 :2420-3.10.1097/01.CCM.0000281856.78526.F4 11. Thongprayoon C, Cheungpasitporn W, Kashani K. Serum creatinine level, a surrogate of muscle mass, predicts mortality in critically ill patients. J Thorac Dis 2016; 8 :E305-11.10.21037/jtd.2016.03.62 : The two sides of creatinine: both as bad as each other?