![ Wood has listed the contraindications to IV
barbiturate use.[227]
(1) When there is respiratory obstruction or an
inadequate airway, thiopental may worsen respiratory
depression.
(2) Severe cardiovascular instability or shock may
preclude its use.
(3) Status asthmatics is a condition in which airway
control and ventilation may be worsened further by
thiopental.
(4) Porphyries may be precipitated or acute attacks
may be accentuated by the administration of
thiopental.
(5) Without proper equipment (IV instrumentation)
and airway equipment (means of artificial ventilation),
thiopental should not be administered.](https://image.slidesharecdn.com/ivinducingagents-150331085207-conversion-gate01/85/INTRA-VENOUS-INDUCING-AGENTS-22-320.jpg)
INTRA VENOUS INDUCING AGENTS
- 1. DR N K AGRAWAL JNMC,SAWANGI
- 2. What are the properties of an ideal IV agent? Should act in one arm brain circulation time Should not cause pain on induction Should not be irritant Should have short half life Metabolites should be non active Not hepatotoxic
- 3. Should not depend on renal for excretion No respiratory depression Should cause hallucination No dissociation Should have hemodynamic stability Should not change cerebral blood flow Least PONV No allergic reaction Useful for TIVA
- 4. Derivative of phenol Have hypnotic properties 2-6 disopropofol Alkyphenol are oil, highly lipid soluble Ctenophore is 1% propofol,10% soybean oil,2.25 glycerol, and 1.2% purified egg Fospropofol is USA FDA Aqua van
- 5. 1 % excreted in urine,2% feces Metabolized hepatic,kidney,lungs Elimination Half life is 2-8 min Distribution half life is 4min to 23 hrs Dose is 1-2 mg/kg Infusion is 200ug/kg/min
- 6. Act on GABA Directly act on neurons of spinal card At dose of 2.5 mg/kg induces hypnosis in 90-100 sec It causes sedation,hypnosis,amnesia Hypnosis lost for 6-10 min Hallicination,sexual fantasis,opisthotonus have been reported High doses are needed for less than 2 yr,with age dose requirement is reduced
- 7. Decreases arterial BP Diastolic BP Stroke volume Peripheral resistance Pawp Pulmonary vascular resistance HR may or may not Myocardial blood flow reduced as well demand
- 8. Decreases ICT Tolerance Reduces CPP Cp50
- 9. Apnea depends on dose, speed of injection,concommitent premedication
- 10. Uses and Doses of Intravenous Propofol Induction of general anaesthesia 1- 2.5 mg/kg IV dose reduced with increasing age Maintenance of general anaesthesia 50- 150 µg/kg/min IV combined with N2O or an opiate Sedation 25-75 µg/kg/min IV Antiemetic 10-20 mg IV, can repeat every 5-10 min or start infusion of 10 µg/kg/min N2O, nitrous oxide.
- 11. Pain on injection Hypotension Myoclonus Apnea thromboplhebities
- 12. Highly alkaline Prepared with water or normal saline Stable for one week Not compatible with pan.,vec,atra,sufen,alfen
- 13. Excreted through liver Metabolites are inactive, water soluble ,excreted in urine
- 14. Bio transformation in four stage oxidation desulfuration dealkylation destruction
- 15. Dose is 4-5 mg/kg Half life is 7-17 hrs its affinity for fat, relatively large volume of distribution, and low rate of hepatic clearance, thiopental can accumulate in tissues, especially if given in large doses over a prolonged period. The plasma drug level increases when repeat doses of drug are given.
- 16. Act in one arm brain circulation time Ultra short acting Crosses blood brain barrier Bound to albumin
- 17. Dose dependant CNS Depression Decreases cerebral metabolic rate Protect brain from ischemia Reduces CMRO2
- 18. On injection garlic or onion test in 40% Allergic reaction Irritation necrosis
- 19. Infuse normal saline Heparin Nerve block
- 20. Increases HR Peripheral vascular resistance decreased Negative inotropic effect Fall in cardiac out put Decreases ventricular filling Decreases sympathetic outflow CNS
- 22. Wood has listed the contraindications to IV barbiturate use.[227] (1) When there is respiratory obstruction or an inadequate airway, thiopental may worsen respiratory depression. (2) Severe cardiovascular instability or shock may preclude its use. (3) Status asthmatics is a condition in which airway control and ventilation may be worsened further by thiopental. (4) Porphyries may be precipitated or acute attacks may be accentuated by the administration of thiopental. (5) Without proper equipment (IV instrumentation) and airway equipment (means of artificial ventilation), thiopental should not be administered.
- 23. It is imidazole derivative Molecular wt 342.69 Water insoluble Ph 6.9 Dose not precipitate
- 25. general anaesthesia 0.2-0.6 mg/kg IV Maintenance of general anaesthesia 10 µg/kg/min IV with N2O and an opiate Sedation and analgesia Limited to periods of brief sedation because of inhibition of corticosteroid synthesis N2O, nitrous oxide.
- 26. The primary action of etomidate on the CNS is hypnosis, which is achieved in one arm–brain circulation after a normal induction dose (0.3 mg/kg). Etomidate has no analgesic activity. Plasma levels required for the maintenance of anaesthesia are approximately 300 to 500 ng/mL, for sedation are 150 to 300 ng/mL, and for awakening are 150 to 250 ng/mL mechanism by which etomidate produces hypnosis is fully known
- 27. Reduces CMR and CBF No change in MAP CPP maintain or increased
- 28. Dose not affect ventilation No histamine release No effect on co2 response No effect on Pao2 PACO2 slightly increased
- 29. NO CHANGE IN HR,MAP,STROKE VOLUME,CARDIAC INDEX,PAWP, CVP,
- 30. It provide sedation hypnosis, anxiolysis Analgesia sympatholysis DOSE- 0.25 to 1 mg/kg
- 31. Metabolize in liver 2% Metabolite are active 85% by kidney 14% via liver
- 32. Rapidly distributed and extensively metabolized in liver Excreted through urine and feces Sensitive half life 4-6 min Half life 2-4 hours
- 33. SEDATIVE- the patients are awake and responsive ANALGESIA-good analgesic, when given in epidural space action within 2-20 min Absorbed in CSF Little effect on ICP CBF
- 34. Ventilatory response increased Response to co2 increased RR increased Paco2 increased by 20%
- 35. Decrease in HR-Sympathetic vascular resistance Hence decreases cardiac out put cardiac out put