Archive | July 2018

QUOTE FOR TUESDAY:

Anemia occurs when you do not have enough red blood cells or when your red blood cells do not function properly. It is diagnosed when a blood test shows a hemoglobin value of less than 13.5 gm/dl in a man or less than 12.0 gm/dl in a woman.

American Society of Hematology

QUOTE FOR MONDAY:

“Diffusion is by far the most important process involved in the transport of electrolytes and solutes in peritoneal dialysis (PD). Examples of such solutes include: Urea, Creatinine, K+, H+, HCO3, Phosphate, Albumin, proteins and toxins3,7. Diffusive transport of Na+ and Ca2+ is minimal.”

Advanced Renal Education (advancedrenaleducation.com)

Peritoneal Dialysis

Peritoneal dialysis is a commonly used form of renal replacement therapy worldwide, although less frequently utilized in the United States (around 10% of prevalent dialysis patients). Two major variations of peritoneal dialysis are commonly used:

  • Continuous ambulatory peritoneal dialysis (CAPD): The patient performs exchanges manually three to four times per day.
  • Automated peritoneal dialysis (APD): An automated cycler performs multiple nighttime exchanges. At the end of this time the patient either instills fluid in the abdomen for a daytime dwell- continuous cycling peritoneal dialysis (CCPD) or leaves no dialysate in the abdomen for the daytime- nocturnal intermittent peritoneal dialysis (NIPD). NIPD is probably not suitable for patients with minimal residual kidney function (RKF).Important goals for a PD patient to achieve include: normalization of acid-base abnormalities, bone and mineral metabolism abnormalities, blood pressure, nutritional status, and functional status.Ultra-filtration failure is clinically recognized as the inability to maintain normal fluid homeostasis. While peripheral and pulmonary edema are specific findings of volume overload, more sensitive signs include hypertension and weight gain. In the evaluation of volume overload, the provider must assess contributing factors such as dietary sodium excess, non-compliance with medications or with the dialysis regimen, episodes of hyperglycemia (which decrease the osmotic stimulus for water removal), and decreased residual kidney function.

Difficulty with ultra-filtration may be associated with dialysate leaks. Leaks can occur into the pleural space (hydrothorax), abdominal wall (causing localized edema), or into a hernia. Due to sequestration of fluid and increased lymphatic absorption, ultrafiltration is decreased.

A rare condition, encapsulating peritoneal sclerosis (EPS) may present with ultrafiltration failure. The patient may also have symptoms of uremia (due to inadequate solute removal), nausea/vomiting, decreased appetite, and weight loss.

Soon after an episode of peritonitis, a decrease in drain volume can be detected in many patients. This may explain the correlation between peritonitis and a high rate of cardiovascular events.

Tests Performed:

Peritoneal equilibration test (PET)

After an overnight dwell, 2 liters of 2.5% dextrose solution is instilled and dwells for 4 hours. At time 0, 2 hrs, and 4 hours, samples of dialysate urea, glucose, sodium, and creatinine are measured along with serum values at 2 hours. One can then calculate the ratio of dialysate/plasma (D/P) creatinine and the ratio of dialysate glucose at 4 hrs to time 0 (D/Do glucose).

Patients who have rapid absorption of glucose and/or rapid removal of creatinine are classified as rapid (or high) transporters while patients who have slow equilibration of urea, creatinine, and dextrose are slow transporters. Using published nomograms, patients can be classified in one of four categories: High, High-Average, Low-Average, and Low transporters.

PET allows the provider to tailor a dialysis prescription to the patient’s peritoneal characteristics. In general, fast transporters will have better ultrafiltration with shorter exchanges and usually are treated with CCPD or NIPD. One should perform the first PET test 4 – 6 weeks after initiating dialysis as it may be inaccurate immediately after starting PD. Similarly, a PET should not be performed within one month of an episode of peritonitis. A PET only needs to be repeated for a clinical change. There is no role for routine monitoring of transport status.

Dialysate and urine collection for urea

  • Based on a 24 hour collection of urine and sample of drained dialysate over 24 hours.
  • Dialysis dose is typically quantified by the removal of urea (Kt/Vurea). The daily peritoneal Kt urea is calculated by multiplying D/P urea by 24 hour drain volume. To normalize for urea distribution volume (V), which is assumed to be total body water, Kt urea is divided by V which can be calculated through many methods (such as Watson method). Finally, to arrive at the weekly Kt/V (std Kt/V) the daily Kt/V is multiplied by 7. To calculate renal (residual) Kt/V, U/P urea is multiplied by 24 hour urine volume and divided by V. The renal Kt/V is multiplied by 7 as well. The renal Kt/V and peritoneal Kt/V can then be added together to give the total Kt/V result.
  • In patients who rely on residual kidney function to achieve the minimum acceptable weekly Kt/V urea of 1.7, urine collection should be done every two months; dialysate collection and urine collection is otherwise typically done every four months.
  • Observational studies suggested that higher Kt/V urea values are correlated with decreased mortality. However, the early studies did not separate renal urea removal from dialytic urea removal. Subsequent analysis of large cohorts, such as CANUSA, have demonstrated that the presence of residual kidney function is far more important to survival than peritoneal urea removal.
  • Three randomized studies have compared different targets of solute removal in PD patients
    • ADEMEX (Mexico): Achieved peritoneal Kt/V 2.2 vs 1.8. No difference in mortality or hospitalizations were seen although more patients withdrew from the low dose group due to uremia.
    • Lo WK et al (Hong Kong): Patients randomized to three total (renal + peritoneal) Kt/V targets-1.5 to 1.7, 1.7 to 2.0, and > 2.0. This study demonstrated no difference in survival or hospitalizations but patients in the lowest dose group had worse anemia and higher erythropoietin requirements. Patients in that group were more likely to be removed from the study by their physician due to uremic symptoms.
    • Mak et al (Hong Kong): Patients on CAPD randomized to extra exchange or not. Achieved peritoneal Kt/V was 1.56 vs 1.92. There was no difference in serum albumin but higher dose group had fewer hospitalizations.
  • Most national and international guidelines recommend achieving total Kt/V urea of >=1.7

Abdominal X- ray/Peritoneography

  • Plain abdominal X-rays are performed to evaluate for malposition of the peritoneal catheter.
  • The normal position of catheter is in the pelvic gutter.
  • In patients with normal inflow of dialysate but problems with outflow, the most common underlying cause is constipation. However, if symptoms do not improve after resumption of normal bowel movements, abdominal X-ray should be done to assess catheter position.
  • For peritoneography, the initial X ray is taken, then 100-200 ml non-ionic contrast is mixed into a 2L dialysate bag and instilled in the patient. The patient changes positions to mix dialysate and a repeat X ray is taken.
  • Can be used to diagnose an entrapped catheter or a peritoneal leak.

Abdominal computed tomography scan

  • Can be used to evaluate the presence of dialysate leaks. Contrast injection as per peritoneography can help to delineate the leak.
  • Abdominal computed tomography (CT) scan can also be used when EPS is suspected. Typical imaging findings include peritoneal calcifications, thick-walled “cocoon” encasing the intestines, and bowel dilatation.

 

QUOTE FOR THE WEEKEND:

Cardiomyopathy refers to diseases of the heart muscle. These diseases have many causes, signs and symptoms, and treatments. The heart muscle becomes enlarged, thick or rigid in cardiomyopathy, and in rare cases the muscle tissue is replaced with scar tissue.”

American Heart Associaton

Part I Cardiomyopathy

Cardiomyopathy (kahr-dee-o-my-OP-uh-thee) is a disease of the heart muscle that makes it harder for your heart to pump blood to the rest of your body. Cardiomyopathy can lead to heart failure.

The main types of cardiomyopathy include dilated, hypertrophic and restrictive cardiomyopathy. Treatment — which might include medications, surgically implanted devices or, in severe cases, a heart transplant —this would all depend on which type of cardiomyopathy you have and how serious it is.

Symptoms

There might be no signs or symptoms in the early stages of cardiomyopathy. But as the condition advances, signs and symptoms usually appear, including:

  • Breathlessness with exertion or even at rest
  • Swelling of the legs, ankles and feet
  • Bloating of the abdomen due to fluid buildup
  • Cough while lying down
  • Fatigue
  • Heartbeats that feel rapid, pounding or fluttering
  • Chest discomfort or pressure
  • Dizziness, lightheadedness and fainting

Signs and symptoms tend to get worse unless treated. In some people, the condition worsens quickly; in others, it might not worsen for a long time.

When to see a doctor

See your doctor if you have one or more signs or symptoms associated with cardiomyopathy. Call 911 or your local emergency number if you have severe difficulty breathing, fainting or chest pain that lasts for more than a few minutes.

Because some types of cardiomyopathy can be hereditary, if you have it your doctor might advise that your family members be checked.

Causes

Often the cause of the cardiomyopathy is unknown. In some people, however, it’s the result of another condition (acquired) or passed on from a parent (inherited).

Contributing factors for acquired cardiomyopathy include:

  • Long-term high blood pressure
  • Heart tissue damage from a heart attack
  • Chronic rapid heart rate
  • Heart valve problems
  • Metabolic disorders, such as obesity, thyroid disease or diabetes
  • Nutritional deficiencies of essential vitamins or minerals, such as thiamin (vitamin B-1)
  • Pregnancy complications
  • Drinking too much alcohol over many years
  • Use of cocaine, amphetamines or anabolic steroids
  • Use of some chemotherapy drugs and radiation to treat cancer
  • Certain infections, especially those that inflame the heart
  • Iron buildup in your heart muscle (hemochromatosis)
  • A condition that causes inflammation and can cause lumps of cells to grow in the heart and other organs (sarcoidosis)
  • A disorder that causes the buildup of abnormal proteins (amyloidosis)
  • Connective tissue disorders

Types of cardiomyopathy include:

  • Dilated cardiomyopathy. In this type of cardiomyopathy, the pumping ability of your heart’s main pumping chamber — the left ventricle — becomes enlarged (dilated) and can’t effectively pump blood out of the heart.Although this type can affect people of all ages, it occurs most often in middle-aged people and is more likely to affect men. The most common cause is coronary artery disease or heart attack.
  • Hypertrophic cardiomyopathy. This type involves abnormal thickening of your heart muscle, particularly affecting the muscle of your heart’s main pumping chamber (left ventricle). The thickened heart muscle can make it harder for the heart to work properly.Hypertrophic cardiomyopathy can develop at any age, but the condition tends to be more severe if it becomes apparent during childhood. Most affected people have a family history of the disease, and some genetic mutations have been linked to hypertrophic cardiomyopathy.
  • Restrictive cardiomyopathy. In this type, the heart muscle becomes rigid and less elastic, so it can’t expand and fill with blood between heartbeats. This least common type of cardiomyopathy can occur at any age, but it most often affects older people.Restrictive cardiomyopathy can occur for no known reason (idiopathic), or it can by caused by a disease elsewhere in the body that affects the heart, such as when iron builds up in the heart muscle (hemochromatosis).
  • Arrhythmogenic right ventricular dysplasia. In this rare type of cardiomyopathy, the muscle in the lower right heart chamber (right ventricle) is replaced by scar tissue, which can lead to heart rhythm problems. It’s often caused by genetic mutations.
  • Unclassified cardiomyopathy. Other types of cardiomyopathy fall into this category.

Risk factors

There are a number of factors that can increase your risk of cardiomyopathy, including:

  • Family history of cardiomyopathy, heart failure and sudden cardiac arrest
  • Long-term high blood pressure
  • Conditions that affect the heart, including a past heart attack, coronary artery disease or an infection in the heart (ischemic cardiomyopathy)
  • Obesity, which makes the heart work harder
  • Long-term alcohol abuse
  • Illicit drug use, such as cocaine, amphetamines and anabolic steroids
  • Certain chemotherapy drugs and radiation therapy for cancer
  • Certain diseases, such as diabetes, an under- or overactive thyroid gland, or a disorder that causes the body to store excess iron (hemochromatosis)
  • Other conditions that affect the heart, such as a disorder that causes the buildup of abnormal proteins (amyloidosis), a disease that causes inflammation and can cause lumps of cells to grow in the heart and other organs (sarcoidosis), or connective tissue disorders

Complications

Cardiomyopathy can lead to other heart conditions, including:

  • Heart failure. Your heart can’t pump enough blood to meet your body’s needs. Untreated, heart failure can be life-threatening.
  • Blood clots. Because your heart can’t pump effectively, blood clots might form in your heart. If clots enter your bloodstream, they can block the blood flow to other organs, including your heart and brain.
  • Valve problems. Because cardiomyopathy causes the heart to enlarge, the heart valves might not close properly. This can lead to a backward flow of blood.
  • Cardiac arrest and sudden death. Cardiomyopathy can lead to abnormal heart rhythms. These abnormal heart rhythms can result in fainting or, in some cases, sudden death if your heart stops beating effectively.

Prevention

In many cases, you can’t prevent cardiomyopathy. Let your doctor know if you have a family history of the condition.

You can help reduce your chance of cardiomyopathy and other types of heart disease by living a heart-healthy lifestyle and making lifestyle choices such as:

  • Avoiding the use of alcohol or cocaine
  • Controlling high blood pressure, high cholesterol and diabetes
  • Eating a healthy diet
  • Getting regular exercise
  • Getting enough sleep
  • Reducing your stress

QUOTE FOR FRIDAY:

“Retinal detachment separates the retinal cells from the layer of blood vessels that provides oxygen and nourishment. The longer retinal detachment goes untreated, the greater your risk of permanent vision loss in the affected eye.”

MAYO Clinic

Retinal Detachment

The retina is the light-sensitive tissue lining the back of our eye. Light rays are focused onto the retina through our cornea, pupil and lens. The retina converts the light rays into impulses that travel through the optic nerve to our brain, where they are interpreted as the images we see. A healthy, intact retina is key to clear vision.

The middle of our eye is filled with a clear gel called vitreous (vi-tree-us) that is attached to the retina. Sometimes tiny clumps of gel or cells inside the vitreous will cast shadows on the retina, and you may sometimes see small dots, specks, strings or clouds moving in your field of vision. These are called floaters. You can often see them when looking at a plain, light background, like a blank wall or blue sky.

As we get older, the vitreous may shrink and pull on the retina. When this happens, you may notice what look like flashing lights, lightning streaks or the sensation of seeing “stars.” These are called flashes.

Retinal tear and retinal detachment

Usually, the vitreous moves away from the retina without causing problems. But sometimes the vitreous pulls hard enough to tear the retina in one or more places. Fluid may pass through a retinal tear, lifting the retina off the back of the eye — much as wallpaper can peel off a wall. When the retina is pulled away from the back of the eye like this, it is called a retinal detachment.

The retina does not work when it is detached and vision becomes blurry. A retinal detachment is a very serious problem that almost always causes blindness unless it is treated with detached retina surgery.

A retinal tear or a detached retina is repaired with a surgical procedure. Based on your specific condition, your ophthalmologist will discuss the type of procedure recommended and will tell you about the various risks and benefits of your treatment options.

Torn retina surgery

Most retinal tears need to be treated by sealing the retina to the back wall of the eye with laser surgery or cryotherapy (a freezing treatment). Both of these procedures create a scar that helps seal the retina to the back of the eye. This prevents fluid from traveling through the tear and under the retina, which usually prevents the retina from detaching. These treatments cause little or no discomfort and may be performed in your ophthalmologist’s office.

Laser surgery (photocoagulation)
With laser surgery, your ophthalmologist uses a laser to make small burns around the retinal tear. The scarring that results seals the retina to the underlying tissue, helping to prevent a retinal detachment.

Freezing treatment (cryopexy)
Your eye surgeon uses a special freezing probe to apply intense cold and freeze the retina around the retinal tear. The result is a scar that helps secure the retina to the eye wall.

Detached retina surgery

Almost all patients with retinal detachments must have surgery to place the retina back in its proper position. Otherwise, the retina will lose the ability to function, possibly permanently, and blindness can result. The method for fixing retinal detachment depends on the characteristics of the detachment. In each of the following methods, your ophthalmologist will locate the retinal tears and use laser surgery or cryotherapy to seal the tear.

Scleral buckle
This treatment involves placing a flexible band (scleral buckle) around the eye to counteract the force pulling the retina out of place. The ophthalmologist often drains the fluid under the detached retina, allowing the retina to settle back into its normal position against the back wall of the eye. This procedure is performed in an operating room.

QUOTE FOR THURSDAY:

Healthcare-associated infections (HAIs) represent a huge problem and the figures from the CDC and ECDC give a sense of its scale: Respectively, they estimate that each year, 1.7 million people in the US and 4.2 million in Europe acquire a HAI.

Centers for Disease Control and Prevention

QUOTE FOR WEDNESDAY:

“Today, stem cells are mainly used in the treatment of disease and in tissue regeneration. They largely come from one of three sources – cord blood, bone marrow and peripheral blood. Cord blood stem cells are found in the blood of the umbilical cord.  BE THE MATCH (National Marrow Donor Program) in their efforts to reach expectant parents across the nation with useful facts and tips on why and how to save a newborn’s cord blood.”

AHC-AmericanHealthCouncil.org

QUOTE FOR TUESDAY:

“The cause of intussusception is not known. It may occur more frequently in people who have relatives who also had intussusception.”

Stanford Children’s Health/Lucile’s Packard Children’s Hospital