September, 2010 | Master Of Medicine

Monthly Archives: September 2010

Measles and pertusis

There are many similarities between measles and pertusis.

Measles

  • Caused by paramyxo virus(RNA )
  • Only source of infection is a case of measles
  • No carriers
  • Virus cannot survive outside the body
  • Koplik’s spots.
  • Rubella is less communicable than measles because of he absence of cough in rubella.
  • SAR 90%

Pertusis

  • Incubation period 7-14 days, never more than 3 weeks
  • Most infectious during catarrhal stage
  • Source of infection is a case of pertusis
  • No evidence of subclinical infecton or chronic carrier stage.
  • SAR is 90% similar to Chickenpox and measles

Vitamin A daily requirements and dose

  1. Retinol ,Retinal and retinoic acid are the three forms.
  2. Retinal is present in the rods and cones in retina.
  3. Children between 6 months to 1yr given-1 lakh IU Vit A
  4. Children between 1 yr and 6yrs- 2 Lakh IU Vit A every 6 months
  5. Treatment of Xeropthalmia-2lakh IU orally for 2 successive days.
  6. First clinical sign of Vit A deficiency-Conjunctival Xerosis.
  7. Bitots spots are seen on bulbar conjunctiva on either side of cornea.

Recommended daily intake of Vit A

  1. Adults-600micro grams
  2. Pregnancy-600 micro grams
  3. Lactation -950
  4. Infants -350
  5. Children-400
  6. 7-12 yrs-600

 

Null hypothesis and P value

Null hypothesis states that there is no significant diiference between the two values.

P value indicates the probability of the Null hypothesis being true ie the difference is due to chance.

By convention a null hypothesis is rejected if P<=.05 ie if there is less than 5% chance that the difference is due to chance.

Methods of measuring body fluid volumes

60% of TBW is water- 20% ECF and 40%ICF

Out of 20% ECF- 15% is Interstitial fluid and 5% is plasma.

Total blood volume is 8% including plasma +cells.

Method’s to measure.

Plasma volume

  • Evans blue-T1824
  • Serum albumin labelled with radioactive iodine.

ECF

  • Inulin
  • Mannitol
  • Sucrose

TBW

  • Deuterium oxide
  • Tritium oxide
  • Aminopyrine

Red cell volume

Tagged RBC’S

Classification of Hormones

Hormones are classified into 3 groups.

Steroid Hormones.

  • Glucocorticoids
  • Mineralocorticoids
  • Estrogens
  • Progestins
  • Androgens

Aminoacid derivative

  • Derived from aminoacid tyrosine.
  • Catecholamines
  • Thyroid hormones

Peptide/Protein hormones

  • Parathormone
  • Calcitonin
  • Insulin
  • Glucagon
  • Pituitary hormones

Malignant Hyperthermia.

  • Life threatening event triggered by administration of anaesthetics and NM blocking agents.
  • Triggered by uncontrolled release of Ca2+ from sarcoplasmic reticulum.
  • Association seen with mutation of gene Ry-R1 encoding for Skeletal muscle Ryanodine receptors
  • Severe hyperthermia,Contracture and rigidity,Metabolic acidosis,Tachycardia are features.
  • Drugs which trigger-Halothane,Sevoflurane,Isoflurane,Succinylcholine
  • Treated by cessation of anaesthetic,IV administration of Dantrolene along with procainamide because of possbility of Ventricular fibrillation.

Hypoxia types

Hypoxic Hypoxia

Due to inadequate PO2 in blood.

Anemic Hypoxia

  • Due to quantitative or qualitative deficiency of Hb.
  • Eg: Severe anemia, CO poisoning.

Stagnant/circulatory hypoxia.

  • Due to circulatory failure.
  • PO2 is normal

Histotoxic Hypoxia

  • PO2 is normal.
  • Due to failure of cellular metaboloc processes
  • Eg: Cyanide poisoning inhibiting cytochrome oxidase.

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