The Art Of Phlebotomy: Science or Bloodletting?

Education for Needle Phobias

Needle fears are quiet common. Some people experience what is called vasovagal reaction at the thought of getting their blood drawn for a lab test. The vagus nerve is large nerve that runs down the center of the body. It can be over stimulated by stomach churning, and anxiety. When it is stimulated by emotional reactions – people sometimes pass out. This is because the stimulation causes sudden a drop in blood pressure. My cousin told me he experienced this reaction when he got his blood drawn. He thought that the lab tech was injecting air into him when the test was done, but that perception was erroneous. Not understanding how the system worked may have triggered his reaction. When blood is drawn, the blood is sucked into the tube by a small vacuum in the tube, no air is injected.

Many misconceptions can lead to unfounded fears around lab work and needles. Some of the fears are based on primitive ideas. Needles are sometimes perceived as an invasive threat; consciousness of blood is perceived in an emotional way by some.

Sometimes the “idea” of blood, or losing it makes people queasy enough to provoke reactions that are extreme such as vasovagal responses or anxiety. Anxiety leads to avoidance. Images of Vampirism, and "blood letting” rise to consciousness. Some people see blood as “life essence.” That is superstition.The vampires see it that way. but they are badly mistaken. Blood is not life essence. It is simply "necessary," in the same way nervous tissue is necessary. Sorry. No melodrama here. A little education in laboratory science and medical phlebotomy is described here for your edification.

Blood has been long seen as “life essence” because the techniques for maintaining homeostasis in blood volume have been absent in human medicine for so long. In the past and for most of our history, we know that massive bleeding from battle wounds or accident, would rapidly lead to death. But emergency interventions to stop bleeding have evolved: first aide techniques, for example. Then surgery evolved - as well as a science to replace blood volume with compatible blood components: (Transfusion.) So, we need to look at blood in a little less of a medieval and emotional sense. The vampires will have to be exposed to a little sun light cast into their dark worlds. I imagine they will feel a little silly for all the trouble they have caused, Let's look at their favorite snack a little closer. They are bound to be disappointed.

What is blood ?

Blood is not an “essence.” (Insert Vampire frown here.) It is a tissue like other tissues: nervous, liver, cardiac tissue.

It is a a solution composed of saline. It contains components such as : red cells, and white cells, dissolved nutrients, electrolytes (sodium, potassium, calcium, chloride.) It contains elements such as phosphorus and metals. It has components that act in the self protective immune response. Blood contains immune antibodies, and white cells that attack “non self..” The immune response to non self is necessary, as many systems within the body must remain sterile to function. Otherwise the function would be impeded by competing foreign cells, such as bacteria, or by viral particles; tissues would be damaged by exotoxins from bacteria which rise in concentration as they procreate.

Blood has it's own self protection system; factors that stop bleeding. It uses platelets and coagulation factors. Platelets, like other blood components, are made from the bone marrow. The clotting elements in blood are manufactured by the liver. Platelets act as plugs when there s a hole in an otherwise self contained system. That system` is the vasculature ( The veins and arteries.) The clotting. or coagulation factors. prevent the loss of blood volume within the vasculature by creating “clots.” Clots are another form of plug . So two plug mechanisms are contained in blood to cope with wounds. In fact, both plugs are used after your blood test.

Platelets aggregate first at the site of the puncture. They are very sticky, and they adhere to one another, and they are the first response to minor and major bleeding, next comes a blood clot. Venipuncture for a lab test, is not a major battle wound, so no large number of Platelets or big clots are needed to stop the bleeding, Barely a band aide is needed but only to keep the site clean.

[*Note: The adequacy of this plugging system is checked by another lab test called a bleeding time. This is a test where 4 or so sharp edges are poked into the skin, and a stop watch is started. The little wounds bleed a little, the lab tech dabs the skin with gauze as the small wounds bleed until the bleeding stops. Then the watch is stopped. The mechanism is working fine if the bleeding stops in less than nine and ½ minutes. Prolonged bleeding times could mean a clotting factor deficiency, or – a platlet deficiency or both. This is an important test to do before major surgery for obvious reasons, as surgeries often involve incisions, and incisions mean bleeding. Blood loss is minimized by testing natural defenses. The bleeding time test doesn't hurt.

[The bleeding from a blood draw for a lab test stops in seconds from platlet aggregation and a tiny intravenous clot.]

Human and animal blood has lot's of functional units. So some knowledge about those functions reduces primal fears, some fears are just too vestigial. Let's discuss one unit called: The red cell (The medical term for the red cell is Erythrocyte)

The red cells carry the oxygen that comes from breathing. They also absorb CO2 from waste at the cellular level. CO2 is a waste product from the metabolism that is always occurring in every cell of the body. Oxygen is required for that metabolism. Red cells also absorb excess potassium, and glucose. These are two of many molecules that might change the osmolarity of the blood if not contained with the red cells. Some osmolarity is regulated by red cells as a first regulatory response (renal excretion is the other ) as in the case of sugar and potassium, An excess of blood glucose, for example,would change that osmolarty. This change would cause fluid to move from the tissues into the blood, and that would cause an unwanted rise in blood pressure. So red cells hide the sugar inside their cell walls until it can either be excreted or carried into the cells by insulin. An excess of potassium in amounts that cannot be excreted fast enough due to poor kidney function, or exogenous overdose, would be cardio-toxic, so red cells absorb the excess to prevent heart damage.

These are secondary functions of red cells . A main function for red cells though is: oxygen transport. Oxygen is delivered to all other tissues at the cellular level. Oxygen is bound to an iron atom at the center of the hemoglobin molecule inside of the red cell. There are four atoms of iron, within each hemoglobin molecule. And each binds one atom of oxygen. There are lots of hemoglobin molecules in each red cell. And lots of red cells in the vasculature.

How many red cells are there? The average number is 4.0 – 5.0 K/u. That's s four to five thousand red cells per micro liter ( one millionth of a liter. ) There are one million times that amount per liter of blood. Multiple that time 5 to 6 liters of blood we have, we can see clearly that we can spare a little blood for a lab test.

Red cells are made from stem cells in the bone marrow (White cells and Platlets are made there too. They are being made constantly, and the life span of single red cell is about 120 days. But nothing goes to waste in the body. The old red cells go to the spleen and are broken down - then the stroma from their break down goes to the liver where it is transformed into bile. Bile is excreted by the gallbladder where it enters the large intestines and it is used to breakdown fats from a fatty meal aided by lipase from the Pancreas. This is another useful function for red cells. Even decrepit cells have a purpose.

Red cells are of an ideal size and morphology (shape.) Big cells are not good. Small cells and irregularly shaped cells are indicative of disease. Historically, these counts were done manually in many minutes, now they are done by machine in seconds.

The blood also picks up carbon dioxide waste, a by product of cellular metabolism, and delivers it to the lungs to be exhaled, CO2 is carried in the veins, while bound oxygen is carried in arteries. Blood is sterile within the vasculature.. The introduction of bacteria into that system is called Septicemia.

Now that we've boggled the vampires are still you scared of blood and medical tests?

Shouldn't be. There is too much science that is happening here that is valuable to you. So let's do a test. This test won't hurt. How about a simple test. Let's do a small finger stick and get a few drops of blood. Since you've learned a little about blood, you can tolerate that.. At least imagining a finger stick shouldn't a bother you. (insert finger poke here.) There you go, very good. We have a few drops of blood. Let's do a test. Now: If you can imagine a capillary tube filled from a finger stick from that one or two drops let' s put it in this centrifuge, To balance it on the other side, we will put an empty capillary tube.

Ok, lets spin it at 1500 rpm for 3 minutes? If it is spun at high speed, note that the solids separate from the liquid (The liquid is Plasma. The liquid minus clotting factors is called Serum.) After three minutes, the solids have precipitated to one side, and they are visibly mostly red cells. About 40 percent of the tube would look “red.” But there'd be a tiny buffy coat at the top ( That is made of white cells.) Most of the capillary tube would be plasma. The plasma is water, or normal saline with dissolved components. Calcium, Potassium, Proteins, Carbohydrates, Fats. Sodium,, metals , and clotting factors.

Some gases are dissolved too...the clotting factors inherent in the liquid portion of the blood, would form clots in time, then the liquid would become serum. Now we have the tissue we call blood broken down into components. And the vampires look disappointed. But, It took centuries of learning to understand what blood actually was and centuries to rid ourselves of the vampires. Blood has functional parts. Too bad for them.

But in our little example of the finger stick. We have just done a lab test that is valuable. It is called The Hematocrit.

From spinning of the blood, seeing the percentage of red cells, how concentrated they are. This gives the medical lab technologist a lot of information. The test is called the hematocrit - the concentration of red cells per unit volume of the blood, expressed as a percentage. It should be 40 percent of the total volume. On average it is in the of range 36 to 42 percent. (Averages differ for men and women, the lower average is for women. ) Higher concentrations of red cells could mean there's less fluid due to dehydration, or, it could mean too many cells are being made. Lower concentrations suggest over hydration or anemia.

A little more on red cell anemia. There are three mechanisms of anemia, they are: blood loss, poor red cell morphology (ill-shaped cells that don't carry oxygen well) or low production due to a variety of causes such as tumor, or aplastic anemia. All types can be treated. A low hematocrit could suggest the presence of anemia.

So just from a finger stick it is obvious, especially combined with clinical signs, that quite a story is told.

So you are still afraid of a little needle stick? Why? There s too much science to be afraid. Maybe you are afraid because you have medieval ideas about what blood is, you see the needle as a weapon, and you don't see the value of the testing yet or you are afraid of blood loss?. We hope to remedy that...

Let's suppose you are drawn for one tube of blood, one “purple top” tube. That is 5 mls of blood. Not very much. No life essence is taken away. 450 mls is drawn when you donate blood. One tube of blood is 90 times less than that. From this test the fluid is replaced immediately. The pint of cells you are down from donation is negligible as you replaced the fluid component in hours, and the red cells in days, as the bone marrow kicks out more to meet the need. So you can see how insignificant this 5 mls is – nor very.

A single purple top tube anti coagulated with EDTA is enough to do many lab tests. Micro liters run into a machine can do a complete blood count. This is count is often called a CBC with differential, and a platelet count.

So I think we are confusing the vampires a little, what do you think? Let's confuse them more:

There are many tests that can suggest the health of red cells and the health of the bone marrow. Since damage to the bone marrow can often lead to Aplastic Anemia, which leads to poor oxygen delivery to other body cells .In anemias we have poor function or a paucity of red cells. But we can also have an excess of them from a disease called Polycythemia Both imbalances have negative effects on cells in other parts of the body due to ischemia caused by poor oxygen delivery. The laboratory test to check for adequate red cells (and other cells) again, is called the CBC. But what does it do? Let's have a closer look.

(Note: Some times more red cells are present in chronic obstructive pulmonary disease so as to maximize available O2.)

The CBC is a count red cells and white cells and platelets. The size and shape of the red cells, their average hemoglobin is expressed numerically as MCV, MCH, MCHC. The CBC is drawn in one purple top tube, But in addition to red cell assessment, white cells are counted, a high white count suggests infection. What type of infection is deduced by looking at the white cells themselves, what type of cell is proliferating?

A print our from a machine for a CBC might read like this *:

CBC: with rough normative values:

WBC: white cells count : 7- 10,000 per cubic mm

RBC: red blood cell count: 4-6k mircolitersl

HGB : hemoglobin: 12-14

HCT: hematocrit: 38-44 M 36 -42 %

MCV: mean corpuscular volume: 70 – 100 mircometers

MCH: mean corpuscular hemoglobin: 32-36 pg/cell
MCHC: mean corpuscular hemoglobin concentration: 36 percent hemoglobin/cell

PLT: Platlet count 150,000 – 350,000 per ml

That is the CBC and from it bacterial viral and parasitic infections can be diagnosed, anemias can be dectected, and blood loss can be guestimated. Transfusion would be mandatory for HCT < 25 percent. (A Postum Partum, a hemmorage caused my wife's Hct, to drop to 18 percent, she got two units of packed cells)

But as an adjunct diagnostic tool a differential is also done as part of the CBC for a better picture. It is done to "look" at all of the blood cells manually. The cap of this purple topped tube is popped off for the manual differential (The machines do them these days but when the machine sees a problem, the results are flagged, and the test is done manually. ) Here's a description of the manual differential:

A drop is put on a slide it is flared or thinned out across the glass. It drys and is stained with Wrights stain. The slide is examined under a microscope on oil immersion higher power. The red cells can be seen easily. And the white cells are seen. This is another test that makes the experience of Phlebotomy (veni puncture) worth it from a diagnostic point of view. Because so much information is right there, in plain view.

What does the lab tech see? Well red cells appear like round red objects with a central area of pallor. The larger cells around them and amid these cells are white cells. The lab tech would look at the red cell morphology The shape and look of the cells, and check for abnormalities. Let's suppose you are a female. The tech may see a problem right away: your cells are a little too small, and a little too red and that information is backed up by the indices (from above: MCV, MCH, MCHC) from the machine, which numerically describes the size and shape and hemoglobin content of your red cells. The manual differential reinforces the numbers..

Red cells that are too small and very red, might suggest iron deficiency anemia. But that is not uncommon, the cause is dietary. Cells that are too large and too pale, suggests B12/folate deficiency either of dietary cause or from Pernicious Anemia. Pernicious Anemia is caused by the lack of a factor produced in the stomach called “intrinsic factor,” this factor facilitates B12 absorption into the blood stream. B12 is essential for making healthy red cells.

In the first case of iron deficiency - dietary supplemental iron might be suggested, especially if a serum iron level suggests deficiency in the presence of clinical signs. In the second case if the tech sees lots of very large cells, MCV > 100 mircometers and hypochromic cells (MCHC =< 36 percent per cell) and the the mean corpuscular hemoglobin is low (< 32pg/cell,) a generic serum vitamin B12 test might be ordered. If that is low, a “Shilling's Test.” for Pernicious Anemia is done. Remember all of this is determined from drawing one tube of blood, running and it through a machine and visually looking at the cells.

(Note: Women have iron deficiency anemias quite commonly, and B12 deficiency is not uncommon. The answer for both as stated is supplements. But in the case of Pernicious Anemia, no amount of supplemental B12 will help if taken by mouth. The Shillings test is diagnostic for Pernicious Anemia. If the cbc suggests pernicious anemia, Shillings is done. An injection of B!2 great enough to bind all of the receptors in the blood is given, then a radioactive pill is given, if radio tagged B12 shows up in the urine, the patient does not have Pernicious Anemia, because that would mean they have stomach intrinsic factor to absorb B12,as the vitamin cannot be bound, it has to be excreted. If it does not show up in the urine, a diagnosis is made. An injection of B12 monthly relieves the symptoms of Pernicious Anemia .)

Back to the Microscope: (Insert vampires scracthing wooden heads here.)

On inspection the red cells may not be normally shaped, or they may look like sickles. This indicates sickle cell anemia., or the may look like bulls eye targets, suggesting liver disease. Or – they may contain visible intra cellular parasites (Malaria.) Or, the visual field may be so obscured with mature white cells and immature white cells, that few red cells are seen, suggesting leukemia or massive overwhelming infection. With degenerative shift to the left. (Never mind that..it's tech talk.)

Or, the maybe normally shaped red cells are visualized with an increase in number of Neutrophils. This suggests bacterial infections, an increase in Lymphocytes suggests viral infections. All of this is seen by doing a simple test using materials costing only fifty cents. The significance to you though is priceless. So why are you afraid of needles again? Ok, let's look at the white cells. Remember we are still using only 5 mls of EDTA anti coagulated blood looking into a mircoscope.

There are five types of white cells or leukocytes.

( See below: The “phils” - Refers to the type of dye they absorb best: dark or light.)

Neutrophils – This cells mediate bacterial infections

Lymphocytes – These cells respond to viral infections

Eosinophils – Respond ton parasitic infection/allergy - inflammations

Basophils - (same as above)

Monocytes - Major role in gobbling up foreign material such as antigen-antibody complexes, post infection.

Under 100x Oil Immersion Microscopy the lab tech counts the white cells when doing a manual differential:

Typically 100 white cells are counted, by type. 60 percentage Neutrophils 8 Monocytes, 30 Lymphocytes, 1 Eosinophil 1 Basophil would be roughly normal. In the absence of allergy, a rise in Eosinophils with clinical signs may mean intestinal parasites are present, such as Giarda Lambda (from bad water) Nematode infections (from ill- cooked meat) pin worm infection (a very common communicable childhood infection, the latter is determined from a quick mircoscopic exam, the parasitic infections from done but the check is more involved from a stool sample for ova and parasites. But only looking at the cells under a microscope can lead to inferences and presumptive diagnoses. The training level of your average lab tech is very high. So be very kind to us.

Taken together with the absolute white blood cell count which is done from mere ul of blood on a machine, a wealth of information is obtained. When the doctor tells you what is wrong, he often asked the lab tech first. But he gets all the credit, and far less pay. Also gets all the heat if he is wrong. The job is sometimes thankless.

By examining white cells under the microscope, lots of diseases can be detected. An extra darker area of blue in the cytoplasm of irregularly shaped lymphocytes suggests exposure to Epstein Barr virus, it may mean mononucleosis. So a follow up serology test might be ordered The presence or many large robin's egg blue cells as seen in this image (plasma cells) with an eccentric nucleus could mean multiple myeloma ( a kind of cancer of the lymphocytes.) Tons of Neutrophils with more immature ones being kicked out by the bone marrow, such as bands or Metamyelocytes or Blasts could mean overwhelming bacterial infection, or Leukemia. Dark blue crystals inside of Neutrophils (toxic granulation)` could suggest exposure to a toxin.

Much more can be determined from a few minutes examining cells under a microscope. The Manual Differential is a very simple test from the point of view preparation and time. but the results say quite a bit.

After all of these tests are done, there'd still be plenty of blood left to do quite a number of other tests: an ammonia level, for example, (some labs use green topped tube, some purple top.) The ammonia level tests liver function in the presence of known liver disease. Another test called a sedimentation rate, which is a generic test for inflammation. The remainder of the blood could be used for a Glycated hemoglobin done routinely in the case of diabetes to see how much glucose the red cells are storing. It is a good measure of how controlled blood sugar is with prescribed diet and treatment. Diabetes needs to be very well controlled. In a sense diabetes is a kind of starvation. The higher the blood glucose the less sugar is being absorbed into the cells. What begins to happen fairly quickly is death of nervous tissue in the periphery, and damage to blood vessels there. The glucose is not being carried into the cells, and they are dying of starvation. The complications thereafter are cascading and degenerative. And so the lab is preventative maintenance for the diabetic by virtue of a simple blood test...the glycated hemoglobin, or HgA1c

So we are seeing quite a bit of info obtained from a single tube of blood and before we saw what info was obtained from a few drops. . Some times as many as five tubes could be drawn, yet, Sometimes only a small number of tests is done with the five tubes or some times a large number may be done, the different tubes are drawn because different tests require different anti coagulant. required, or a preservative is necessary for specific test, Calcium Oxalate is is an example of another anti coagulant. (the blue topped tube). Sometimes the tube should contain nothing. And that means the test requires serum only (such as in serum iron, and fasting blood sugars,and basic clinical chemistry tests.) But if five tubes are drawn, still, only 25 ml is drawn. Not much.

Ok, to you have a little education. You know know that there are good reasons to do the lab tests and you know you aren't losing an amount of blood that will mean anything, or that will make you feel different. But we do have to draw those five tubes now, so let me show you how we do it. And I want you to listen. Imagine this: you won't feel a thing, not if the good lab tech with experience draws your blood, otherwise, in most cases the if the tech is not very experienced. the most you will feel is quick pinch. It's over in less than a minute. You get a sticker for bravery of if you allow you self to see that your needle phobia is un founded Visualize the needle not as going into you, see it instead as parting tissues, a thin pipe going into a larger pipe. It is more of a tap than it is a stick., if done correctly,

The blood is drawn usually from the veins in the antecubital space of the arm, after a tourniquet is applied. This is to make the veins pop out. The needle does not go all the way in. It looks about 1.5 inches long, but only a small fraction of that goes in the lumen of the vein. The pupose of the length is to achieve the proper angle, Sometimes lab techs, think the solution is to go deeper if they get no blood return - that is not the answer. Most times, pulling the needle back is what does it; placing the lumen of the needle in the lumen of the vein. New lab techs may approach a draw this way. The newer techs may forget to enter the vein with the beveled portion of the needle up. Instead, it is upside down, and the opening is occluded at that floor of the venous wall. The blood can't get in the tube that way. So if you see a lab tech approaching the vein, tell them “bevel up.” or “get lost.” Sometimes repositioning the needle is the answer. But putting more needle in the vein is not.

Think of the process as a pipe going into a pipe. And think of the amount of tests that can be done from a negligible amount of blood. You may find thinking in these terms is helpful to quell your needle fears.. And then when you get your tests done, you may be lucky enough to get my wife Mary Sue to draw you blood. She is the best there is...She can get blood painlessly from young and old. She has more experience than anyone I know.

Mary Sue, and experienced lab personnel like her, know that the task with the very young is to prevent trauma. Attitudes and neurosis can develop there. So, skilled psychology is used to reduce fears and risk of an unpleasant visit. Empathy. For Kids, using games and distractions is her forte. The experience should not be a trauma for children. These traumas are unnecessary because, for the most part, the process is fairly painless. An impatient or un-personable phlebotomist can make for a needle phobia early on. And certainly the worst approach is to restrain the child when doing a blood test. Calming the child and entertaining is the best approach. The child sees the experience as almost enjoyable, save for a pinch. And of course, the child is always rewarded and praised for their bravery. They are given an award - a sticker. Or a treat. So if you are an adult phobic, she will treat you the same way, as mostly likely you acquired your phobia the same way kids do...from a bad experience.

Older adults can often present the greatest challenge, as their veins are harder to find, and they are often times scarred or fragile. When the vein is scarred getting blood is harder. Older people have had many lab tests and Iv's in their life times, their circulation is poor, and so drawing older people who have to be drawn regularly is tough. Elderly people who need coumadin blood levels weekly, for example, can be hard to draw blood from, as their veins are battle scared. But my wife is excellent with this age group too.

When your blood is drawn, or mine is, the veins are seen easily. In tech lanquage they are "pipe lines." So you should have no fears. But what are visible veins in younger healthier people are often unseen, especially in the obese and the elderly – like patients described.

These veins must be palpated (felt,) Too often it is guess work. (and more work as applying heat pads to coax the vein to the surface is needed.) The reason for this is the vein is anatomically buried deeper, or the patient is very obese. The needle then becomes like a divining rod. My wife is very good in cases like that for her intuition acquired over the years. With the loads of experience she taps the right spot more often than not. So you'd be lucky to get her. She does not have an easy job.

Phlebotomy as an art, is that level of performance beyond mere training: it is the level at which experience, training, and dedication merge. So, I hope this little treatise helps the next time you visit the lab.

I suppose if the reader had true needle phobia this education would not help much. A real phobia is more serious than normal consternation, or mild needle neurosis. The early experiences with medical professionals are formative. And so, good experiences are helpful to avoid developing needle nervousness of any kind.

One of the saddest cases I had as a nurse, was Type 1 diabetic who had needle phobia. He was so phobic that he could not inject himself with the thin short diabetic needle, even though the injection was subcutaneous and painless. It is possible he was traumatized as a kid. As a result though, into his adult life, he didn't treat his diabetes properly, he eventually died of renal failure. I am thinking he was non compliant with dialysis secondary to needle phobia. He was a homeless patient. And a really nice guy, it made me sad to hear he died, especially when I see how a phobia, has prevented him from treating himself properly ever since he was a child. 'His name was Richard, and I think about him often. He was an example of a worst case scenario related to this problem. So this article is written to enlighten the Richards of the world, and others. Hopefully it will contribute a little in the process of desensitization. There is some perspective for all here though. The science and the purpose of the needle is the point. Pun intended ;)

Here are some images from peripheral blood smear:

Red blood cells with lymphocyte there are platelets here too, They are very small blueish particles beneath the one lymphocyte, amid the normal red cells. More are above and to the right of the one lymphocyte. That is a normal lymphocyte.. But look at some abnorma l one's from some links below. In the first link see a sickled cell amid a bunch of target cells...

Sickling with target cells surrounding the sickle cell.

Here are some atypical lymphocytes seen commonly seen in Mononucleosis. Note size and the spread out cytoplasm and irregular shape when compared to normal lymph above. Those white cells have been sensitized by Epstein Barr Virus.

When the machine does an automated diff, it might flag blood samples if there are abnormalities, a manual differential will be done. The sample below would be be flagged as having too much POIK - Poikiliocytosis, or irregular shape in the red cells. Elliptocytes (below) show up in Thalessemia, infectious anemias and hereditary iron diffeciency anemias. Ovalocytes show up as well. (click link below)

Elliptocytes (abnormal red cells)

The presence of blasts in peripheral blood smears is bad news:
possible leukemia, requires bone marrow histology, to rule out
overwhelming infection vs. Leukemia, this looks like leukemia off the bat, as all you see are blasts, primative white cells forms. This is Leukemia

From above: The blast is a stem cell that differentiates into a particular type of white cells these appear to lymphoblasts, although a tests needs to be done to be sure which type of blast they are.

Malaria in peripheral blood smear. When these bugs mature (Plasmodium Malariae) they burst the red cell, and enter other red cells. This cause anemia, fever. It isn't often that you see this in the US, but I have,. In this image you see one infected red cell. Chloroquine is the treatment.

Other abnormalities that can be visualized from a peripheral blood smear are listed here, this article does not scratch the surface of what can be derived from looking at a simple peripheral blood smear.

PS: There's an interesting little gizmo from one of the ads here, this little device is actually pretty nifty, it's kind of like sonar for locating veins, there's an associated video as well, ain't science moving along: http://www.accuvein.com/video_gallery.php