NEET MDS Lessons
Pharmacology
PLASMA FRACTIONS:
a) Fresh frozen plasma.
b) Platelets.
c) Plasma concentrates.
d) Non-plasma recombinant factor concentrates.
DOBUTAMINE
It is a derivative of dopamine and has relatively β1 -selective action and it also activates α1 receptors and do not have D1 receptor agonistic property. It increases the force of myocardial contraction and cardiac output without significant change in heart rate, blood pressure and peripheral resistance. It is used as inotropic agent and for short term management of CHF and also in patients who are unresponsive to digitalis.
Clotrimazole: Clotrimazole is a potent, specific inhibitor of p450 enzymes.
It is used in some antifungal medications, and in the treatment of yeast infections.
Osmotic diuretics
An osmotic diuretic is a type of diuretic that inhibits reabsorption of water and sodium. They are pharmacologically inert substances that are given intravenously. They increase the osmolarity of blood and renal filtrate.
Mechanism(s) of Action
1. Reduce tissue fluid (edema)
2. Reflex cardiovascular effect by osmotic retention of fluid within vascular space which increases blood volume (contraindicated with Congestive heart failure)
3. Diuretic effect
o Makes H2O reabsorption far more difficult for tubular segments insufficient Na & H2O capacity in distal segments
o Increased intramedullary blood flow (washout)
o Incomplete sodium recapture (asc. loop). this is indirect inhibition of Na reabsorption (Na stays in tubule because water stays)
o Net diuretic effect:
Tubular concentration of sodium decreases
Total amount of sodium lost amount increases
GFR unchanged or slightly increased
Toxicity
Circulatory overload, dilutional hyponatremia, Hyperkalemia, edema, skin necrosis
Agents
Mannitol
Isoflurane (Forane) MAC 1.3%, Blood/gas solubility ratio 1.4
- Better muscle relaxation than with the other halogenated anesthetic agents.
- Isoflurane markedly potentiates the action of the neuromuscular blocking agents.
- Produces rapid onset and recovery of anesthesia.
- Does not sensitize the heart to catecholamines.
- Produces respiratory depression, but produces less cardiovascular depression
- than does halothane.
- It has an extremely low degree of metabolism and is apparently relatively
- nontoxic.
Needle selection
Nerve blocks:
Inferior alveolar- 25 G short (LLU technique)
PSA- 25 G short
Mental/Incisive- 25 G short
Palatal- 27/30 G short/ultrashort
Gow-Gates/Akinosi- 25 G long
Infraorbital- 25 G long
Field Block:
ASA 25/27 short
Infiltration:
Infiltration/SP 25/27 short
PDL/Intraosseous
PDL 27/30 short
Intraosseous 30 short/ultrashort
Stages of anesthesia
Stage I
Analgesia
Still conscious but drowsy
Stage II
Excitement stage
Loss of consciousness, however, irregular ventilation may be present which affects absorption of inhalation agents.
Reflexes may be exaggerated.
This is a very dangerous stage
Stage III
Surgical anesthesia
Loss of spontaneous movement
Regular, shallow respiration
Relaxation of muscles
Stage IV
Medullary paralysis
Death