Lecture 2 - interpretation of laboratory results

Question 1

why are lab results important?

Answer 1

diagnosing - eg TFT in hypothyroidism in pt complaining of tiredness palpation and symptoms of metabolism

monitoring eg crp and wcc in infections

drug adjustment
eg gentamicin based on the concentration, edoxaban based on CRCL

Question 2

what is fluid balance

Answer 2

the body regulates fluid balance through thirst mechanism, antidiuretic hormones and renal mechanism.

Question 3

what are clinical features of dehydration ?

Answer 3

tachycardia, hypotension, skin, eye balls, mucous membranes dry, decreased urine output and consciousness
treat cause and give IV fluid (NaCl + glucose)

Question 4

what does plasma sodium do

Answer 4

reflects the balance of sodium and water

Question 5

when is urea useful for ?

Answer 5

useful for assessing hydration:

Increased in renal failure, high protein intake, GI bleeding, dehydration, starvation

Decreased in liver failure, poor protein diet, anabolic states, overhydration, pregnancy

Question 6

what are HbA1c values and glucose values ?

Answer 6

HbA1c
normal <42 mmil/mol
pre-diabetes: 42 to 47 mmol/mol
diabetes: > 48 mmol/mol

glucose
Fasting BG: 4.0 to 5.9 mmol/L
Two hours after eating < 7.8 mmol/L

for diabetes diagnosis
Fasting BG ≥ 7.0 mmol/L
Random blood glucose ≥ 11.1 mmol/L

Question 7

what is calcium sued for

Answer 7

most abundant mineral. most of calcium is in the bone as hydroxyapatite. it is interlinked with phosphate metabolism.

it is involved in the maintenance of cellular membranes and nervous tissue excitability, contractility of muscle.

Regulated by parathyroid hormone and 1,25 hydroxycholecaciferol controlling GI absorption, bone deposition/ resorption and urinary secretion

Question 8

describe components of whole blood

Answer 8

cellular elements: red blood cells, palters and white blood cells

plasma - water ad proteins such as albumin, globulin and clotting factors. albumin is the main protein in plasma, it regulates colloidal osmotic pressure. oxygen is transported.

Question 9

what are morphological types of anemias ?

Answer 9

1. normocytic normochromic (Normal MCV)
   - causes: anaemia of chronic disease,a cute blood loss, bone marrow failure, haemolytic
   - blood film: normal-sized, normal-colour RBC
2. microcytic hypochromic (Low MCV)
   - causes: iron deficiency anaemia, sickle cell anemaia.
   blood film: low HB, low CV, low MCH, low MCHC
   -Mechanism:low Iron → low Hb synthesis → small, pale RBCs
3. macroytic (high MCV)
   Causes:B12 or folate deficiency
   Blood film:Large RBCs, impaired division
   Mechanism:↓ DNA synthesis → delayed division → large cells