Goodbye-Halothane-Welcome Total Intravenous anaesthesia

a brief history regarding flourishment of Anaesthesia

1. GOODBYE HALOTHANE WHAT WILL BE THE ALTERNATIVES

2. Presented by Dr Sohel Rana Consultant, Anaesthesiology , Shaheed Ziaur Rahman Medical College Hospital, Bogura Dr Nilima Afrin Anirban Anaesthesiologist , Shaheed Ziaur Rahman Medical College Hospital, Bogura

3. WHAT IS ANAESTHESIA Greek an is without and aesthesia is sensation This term is coined by American physician Oliver Wendell Holmes in 1846.

4. GENERAL ANAESTHESIA General Anaesthesia : It is a state of reversible and purposeful insensibility by -loss of consciousness -loss of pain -amnesia and -some degree of muscle relaxation. As no single agent provides all desirable properties, several categories of drugs are combined for optimal anaesthesia .

5. BRIEF HISTORY OF ANAESTHEIA Pre-1846 - The foundation of anaesthesia 1846-1900 - Establishment of anaesthesia 20 th century- Consolidation and growth 21 st century-the future

6. WHY ANAESTHESIA IS NECESSARY To achieve…… Loss of awareness Analgesia Minimize autonomic response to surgical stimuli Muscle relaxation

7. A situation in ancient days : without anaesthesia

8. THAT SITUATION WAS CHANGED BY William Thomas Green Morton (1819-1868) (1819William Thomas Green Morton -1868 ) An American dentist and physician The inventor and revealer of inhalational anaesthesia

9. DEMONSTRATION OF ETHER ANAESTHESIA On 16 th October, In 1846, at the operating theatre of the Massachusetts General Hospital , William Thomas Green Morton demonstrated Ether anaesthesia for excision of tumor under jaw. This incident opened a new path for inhalational anaesthetics in modern surgical practices.

10. ANCIENT LABOR ANALGESIA In 1853 and 1857, John Snow used chloroform to deliver last two children of Queen Victoria. But use of these agents was very much risky for patient’s hemodynamics.

11. ERA OF MODERN INHALATIONAL ANAESTHETIC AGENTS Halothane was first synthesized by C. W. Suckling in 1951 First used clinically by M. Johnstone in Manchester in 1956 Much improved safety profile of Halothane is proved than other older inhalational anaesthetics . By this way, the modern era of fluorinated compounds has been started.

12. ANAESTHESIA COMPRISES Induction -Maintenance of Anaesthesia -Recovery Halothane ; an inhalational general anaesthetic , which is used for induction and maintenance of general anaesthesia .

13. HOW TO CHOOSE A PROPER ANAESTHETIC AGENT Status of organ systems: 1. Cardiovascular system : Degree of suppression of cardiovascular functions , is an important consideration especially with cardiac diseases. 2. Respiratory system : Though inhaled agents produce respiratory depression, they act as bronchodilators. As a result, adequate ventilation and oxygenation during and after surgery is possible.

14. CONTINUED….. 3. Liver and kidney : responsible for distribution and clearance of drugs and are also target organs for toxic effects. 4. Nervous system : The presence of neurologic disorders influences selection of anaesthetic . 5. Pregnancy : If anaesthetics are required during pregnancy, special consideration is essential for maternal and fetal outcome .

15. HALOTHANE PROPERTIES: Halogenated compound (2-bromo-2-chloro-1,1,1-trifluoroethane) Volatile Colorless, pleasant odor, non irritant

16. CONTINUED……. Non explosive, non flammable, light sensitive, so it should be stored in ambered colored bottle. Corrosive, interacts with metal in vaporizers and breathing systems.

17. ADVANTAGES OF HALOTHANE Smooth induction especially in pediatric population Minimal stimulation of salivary and bronchial glands. Bronchodilatation Coronary vasodilator.

18. DISADVANTAGES OF HALOTHANE Arrythmia Possibility of hepatotoxicity especially with repeated administration Slower recovery Post anaesthetic shivering. Malignant hyperthermia: A life threatening condition.

19. WHY HALOTHANE IS BEING SAID “GOODBYE” Few drugs have excited such widespread interest and stimulated as much clinical and laboratory investigation as halothane." —Editorial, Brit. J. Anaesth . (1962). When better option is available, then we should go for newer technique!

20. 1.Side effects on Patients , 2.environmental effects : destructing our “ OZONE ” layer of atmosphere For global safety, we have to say “ GOODBYE ” to cost effective, poor-friendly HALOTHANE ! CONTINUED …

21. ALTERNATIVE OPTIONS Inhalational agents : Isoflurane, Sevoflurane, Desflurane TIVA : Total Intra-Venous Anaesthesia

22. COMPERATIVE STUDIES BETWEEN MODERN VOLATILE ANAESTHETIC AGENTS ISOFLURANE SEVOFLURANE DESFLURANE ADVANTAGES Low cost Bronchodilator Non-arrhythmogenic Suitable for induction Faster onset, offset Non-arrhythmogenic Fast onset/offset DISADVANTAGES Irritant to airway, so induction may not be possible. Expensive Formation of toxic compound Expensive Irritant to airway Heated/pressurized vaporizer required

23. TOTAL INTRA VENOUS ANAESTHESIA It is a technique for induction and maintenance of anaesthesia without administration of any inhaled anaesthetic agent, employing infusion of iv agents alone. But patients breath oxygen , air or mixture of the two.

24. BRIEF HISTORY OF TIVA

25. WHY TIVA BECOMING POPULAR? Demands are changing! In advanced diagnostic and therapeutic modalities, to alleviate patient discomfort. Safe anaesthesia with rapid patient turnover in ambulatory care setting.

26. DRUGS USED IN TIVA Individually or in combination (drugs with fast onset & offset time) HYPNOTICS : Propofol, ketamine, Benzodiazepine ANALGESICS: Remifentanyl , Fentanyl MUSCLE RELAXANTS : Atracurium, vecuronium ADJUVANTS: Dexmedetomidine, Lignocaine

27. SOME EXAMPLES Propofol & Fentanyl : most commonly used Loading dose : Propofol: 1-2.5 mg/kg, Fentanyl:4-20 microgrm /kg Maintenance dose : Propofol: 50-200micgm/kg/min, Fentanyl: 2-10micgm/kg/min Ketamine : Loading dose: 1-2mg/kg, maintenance: 2.5-15 micgm /kg/min Midazolam ; Loading: 0.03-0.1 mg/kg , maintenance ; 0.03-0.1 mg/kg/ hr

28. TYPES OF TIVA

29. CLINICAL APPLICATION OF TIVA Manually controlled infusion: Bristol regimen: (10-8-6) Premedication : 3 micgm /kg fentanyl with 1mg/kg of propofol then infusion of propofol of 10mg/kg/ hr for 10 min,then 8mg/kg/ hr for next 10 min then 6mg/kg/ hr thereafter. Required brain conc ; 3 micgm /ml ,achieved after 12 min. Drawback : For adequate hypnosis in unparalyzed pt , simultaneous administration of fentanyl and nitrous oxide is required. So, its not ideal TIVA

30. CONTINUED…. Target Controlled Infusion (TCI): Computer driven infusion device. Ideal method for TIVA. Pt body wt , target conc entered Advantages: simple to use, avoidance of complex calculations

31. TIVA MONITORING VISUAL : Loss of response to shaking, shouting Loss of hemodynamic response to vigorous jaw thrust, laryngoscopy, intubation Machine : Bispectral index monitor EEG Monitor: recommended when NMBAs are used.

32. INDICATIONS OF TIVA Risk of malignant hyperthermia History of severe PONV Day case surgery Anaesthesia in non theatre environment Avoidance of neuromuscular blockade ( Myasthenia gravis) Transfer of anaesthetized pt ( eg between theatre and icu ) Where ET tube is avoided, eg rigid bronchoscopy

33. ADVANTAGES OF TIVA 1.Avoids adverse effects of volatile anaesthetic agents (PONV, environmental pollution etc ) 2.Suitable for non- theatre environment (MRI suite), 3. Transfer of anaesthetized patients when needed 4.Reduce postoperative pain. 5.Smooth patient recovery.

34. DISADVANTAGES OF TIVA 1.Requires infusion pump or TCI device. 2.Greater risk of awareness(tearing, sweating, tachycardia, hypertension) 3.More expensive than inhalational technique. 4. Elimination of IV agent need more time in comparison to inhalational agents.

35. TIVA SAFETY CHECKLIST R=right drug in right pump E=Everything TIVA dedicated( 3 way TIVA iv line) C=Cannula secure, padded and accessible I=IV fluids connected and running freely P=Pumps (TCI) plugged in and charged E= pEEG monitoring connected and working

36. CONCLUSION Darwin said, “Survival for the fittest”. So we have to receive newer and better options! Halothane has been proved as cost effective and poor friendly drug but considering its adverse effect to both patient and environment, we have to receive better alternatives.