4. Labs

Question 1

what is in a CBC?

Answer 1

• WBC
• hemoglobin
• hematocrit
• platelets

Question 2

what are normal lab values for CBC?

Answer 2

Question 3

with an infection, what is expected to happen to the WBC count after surgery?

Answer 3

• Eventually it should go down,
• but in post-op days 1-2, the WBC may actually increase a bit.
• this is may occur because surgery activates the body’s reaction to the infection.

Question 4

what should be done if the patient’s WBC is over 10?

Answer 4

First, decide if the patient has an infection:

• If there is an infection, then antibiotics and possible incision and drainage (I&D) should decrease the WBC count
• If there is not an infection, then the cause must be determined. Is the increase acute or chronic? Is there another source of infection (other than the foot)? Is the patient on corticosteroids? Is there a combination of medical conditions causing this?

Question 5

what to do if platelets are low

(under 150-350 k/mL)?

Answer 5

can transfuse platelets,

but this is not commonly done

Question 6

what are the minimum levels for hemoglobin and hematocrit for elective surgery?

Answer 6

• Hemoglobin 10 gm/dL
• Hct 30%

Question 7

what should be done if the Hemoglobin/Hematocrit (H/H) is below 10/30?

Answer 7

if necessary, transfuse 1-2 units of packed red blood cells (PRBC)

Question 8

what is the condition called if the Hemoglobin/Hematocrit (H/H) is below 10/30?

Answer 8

anemia

Question 9

what are causes of microcytic, hypochromic anemia?

Answer 9

• Iron deficiency
• thalassemias
• lead poisoning

Question 10

what are causes of macrocytic, megaloblastic anemia?

Answer 10

Vitamin B12/folate deficiency

Question 11

following a transfusion of PRBC,

when will changes in the H/H be seen?

(PRBC = packed red blood cells)

Answer 11

approximately 3 hours

Therefore, order new labs to be drawn 4 hours after last unit given.

Question 12

what is in a BMP?

(BMP = basic metabolic panel)

Answer 12

• sodium
• potassium
• chloride
• carbon dioxide
• BUN
• creatinine
• glucose

Question 13

what is in a CMP?

(CMP = comprehensive metabolic panel)

Answer 13

• BMP
• ALP (alkaline phosphatase)
• ALT (alanine amino transferase, also called SGPT)
• AST (aspartate amino transferase, also called SGOT)
• bilirubin
• albumin
• total protein
• calcium

Question 14

what are normal values for BMP?

Answer 14

Question 15

what do Na+, K+, Cl and CO₂ tell you?

Answer 15

these electrolytes indicate nutritional status

Question 16

what should be done if Na+ is low?

Answer 16

give NSS or regular salt

(NSS = Normal saline solution)

Question 17

normal saline solution

route, other names, indications

Answer 17

• can be administered only via intravenous (IV) access.
• 0.9% Normal Saline (NS, 0.9NaCl, or NSS) is one of the most common IV fluids
• Indications (most hydration needs): hemorrhage, vomiting, diarrhea, hemorrhage, drainage from GI suction, metabolic acidosis, or shock)

Question 18

what should be done if K+ is too low?

Answer 18

• Manage hypokalemia
  
  • Give K-Dur (potassium chloride supplement)
  • Give potassium-rich foods (i.e. banana)

Question 19

hypokalemia: sequelae

Answer 19

Hypokalemia may cause:

• cardiac arrhythmias
• muscle weakness
• paresthesias
• cramps

Question 20

what should be done if the K+ is too high?

Answer 20

• Order EKG
• Manage hyperkalemia
  
  • Calcium gluconate
  • Sodium bicarbonate
  • Dextrose with insulin
  • Kayexalate

Question 21

hyperkalemia: sequelae

Answer 21

Hyperkalemia may cause:

• cardiac arrhythmias
• lethargy
• respiratory depression
• coma

Question 22

what do BUN and creatinine indicate?

Answer 22

renal function

Question 23

what should be done if the creatinine is too high?

Answer 23

• Consult renal if creat is over 1.5 for a couple of results
• Note: creat may be increased after muscle breakdown or loss

Question 24

which is a more important indicator –

BUN or creatinine?

Answer 24

Creat is more important, because BUN is influenced by hydration state

• If the BUN is high but creat is normal, then the patient is most likely dehydrated and rehydration should correct the BUN
• However, if both BUN and creat are high, then the patient most likely has renal damage.

Question 25

what do PT/PTT/INR tell you?

Answer 25

**The coagulable state of the patient:** * If the levels are _high_, it will take longer for the patient to develop a clot and stop bleeding * It **requires blockage of only one pathway to anticoagulate the patient.**

Question 26

what are normal values for PT/PTT/INR?

Answer 26

Question 27

what can cause an **elevated PT/INR**?

Answer 27

**"CAVA, M!"** * Malnutrition * Coumadin * Alcoholism * Vitamin K disorders * Antibiotics

Question 28

what does INR stand for?

Answer 28

International Normalized Ratio

Question 29

why was INR developed?

Answer 29

**INR was devised to standardize all the results** ## Footnote Because there are different methods to determine PT, and thus each lab has a different normal value for PT

Question 30

ff the patient is on **Coumadin** for anticoagulation, what should the _INR_ be?

Answer 30

Intense anticoagulation 2-3

Question 31

what causes the **_PTT to be high_**?

Answer 31

**Heparin** *causes PTT to be high*

Question 32

which pathway does PTT check?

Answer 32

Intrinsic ## Footnote *(think: "PITT", PTT is **_i_**ntrinsic)*

Question 33

which pathway does PT check?

Answer 33

extrinsic ## Footnote *(Think: "PET", with extrinsic measured by PT)*