TCI -Target Controlled Infusion

TCI is an infusion system which allows the anaesthetist to select the target blood concentration required for a particular effect and then to control depth of anaesthesia by adjusting the requested target concentration

Mechanism

Instead of setting ml/h or a dose rate (mg/kg/h), the pump can be programmed to target a required blood concentration.

• Effect site concentration targeting is now included for certain pharmacokinetic models.

• The pump will automatically calculate how much is needed as induction and maintenance to maintain that concentration.

Gentamicin

Gentamicin is a aminoglycoside antibiotic, and can treat many different types of bacterial infections, particularly Gram-negative infection.

Gentamicin works by binding to a site on the bacterial ribosome, causing the genetic code to be misread.

Like all aminoglycosides, gentamicin does not pass the gastro-intestinal tract, so it can only be given intravenously or intramuscularly.

Gentamicin can cause deafness or a loss of equilibrioception in genetically susceptible individuals. These individuals have a normally harmless mutation in their DNA, that allows the gentamicin to affect their cells. The cells of the ear are particularly sensitive to this.

Gentamicin can also be highly nephrotoxic, particularly if multiple doses accumulate over a course of treatment. For this reason gentamicin is usually dosed by body weight. Various formulae exist for calculating gentamicin dosage. Also serum levels of gentamicin are monitored during treatment.

E. Coli has shown some resistance to Gentamicin, despite being gram-negative

Sufentanil

• A synthetic opioid related to fentanyl.
• About 7 times more potent than fentanyl.
• Has a slightly more rapid onset of action than fentanyl.

Carbenicillin

Antibiotic that is chemically similar to ampicillin. Active against gram-negative germs. It is well soluble in water and acid-labile.

Procaine penicillin Procaine penicillin is a combination of benzylpenicillin with the local anaesthetic agent procaine. This combination is aimed at reducing the pain and discomfort associated with a large intramuscular injection of penicillin.

Indications

respiratory tract infections where compliance with oral treatment is unlikely ,syphilis, cellulitis

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