anesthesia ppt medical surgical nursing

ppt

1. UNIVERSITY INSTITUTE OF NURSING ANESTHESIA

2. The word anesthesia is derived from the Greek: meaning insensible or without feeling. ANESTHESIA IS BROKEN DOWN INTO 3 MAIN CATEGORIES LOCAL AND GENERAL. REGIONAL , ALL OF WHICH AFFECT THE NERVOUS SYSTEM IN SOME WAY AND CAN BE ADMINISTERED USING VARIOUS METHODS AND DIFFERENT MEDICATION. ANAESTHESIA ARE AGENT THAT BRIING ABOUT REVERSIBLE LOSS OF SENSATION .

3. ( from Greek αν-, an- , "without"; and, aisthēsis , "sensation"), traditionally meant the condition of having sensation (including the feeling of pain ) blocked or temporarily taken away. It is a pharmacologically induced and reversible state of amnesia , analgesia , loss of responsiveness, loss of skeletal muscle reflexes or decreased stress response , or all simultaneously. These effects can be obtained from a single drug which alone provides the correct combination of effects, or occasionally a combination of drugs (such as hypnotics , sedatives , paralytics and analgesics ) to achieve very specific combinations of results. This allows patients to undergo surgery and other procedures without the distress and pain they would otherwise experience.

4. An alternative definition is a "reversible lack of awareness," including a total lack of awareness (e.g. a general anesthetic) or a lack of awareness of a part of the body such as a spinal anesthetic. The pre-existing word anesthesia was suggested by Oliver Wendell Holmes, Sr. in 1846 as a word to use to describe this state. Anaesthesiology is a special branch of medicine. Nurses working in this area need to have knowledge and skill to care for the patient who is being given premedication, under anaesthesia and recovering.

5. ACCORDING TO willims L o ss of fe e l i ng in all or p a rt of b o dy w ith or w i thout l o ss o f consciousness .the patient was given an injection before surgery According to lippen cott Genral loss of the sense of feeling ,as pain ,heat ,cold, touch,and other less common varieties of sensation . According to devis It is a reversible blocking of pain feeling in whole body or in a part of it using pharmacology or other methods

6. GENERAL AN A ESTHESIA LOCAL ANAESTHS I A REGIONAL ANAESTHE S IA DI S SOCI A TIVE ANESTHESIA

7. Types of anesthesia: REGIONAL ANESTHESIA GENERAL ANESTHESIA LOCAL ANESTHESIA DISSOCIATIVE ANESTHESIA .

8. REGIONAL ANESTHESIA : Regional anesthesia renders a larger area of the body insensate by blocking transmission of nerve impulses between a part of the body and the spinal cord . Two frequently used types of regional anesthesia are spinal anesthesia and epidural anesthesia . •

9. LOCAL ANESTHESIA : Local anesthesia inhibits sensory perception within a specific location on the body, such as a tooth or the urinary bladder

10. SPINAL ANESTHESIA : it is achieved by injection 1.8 ml of 5% lignocaine solution into the subarechnoid apece through a lumber puncture.other drugs which can be used are cinchocaine, procaine and amethocaine. It can cause serious hypotension.

11. EPIDURAL A N E S TH E SI A : It i s a c h i e v ed by injection 1 to 2 % of lignocaine solution in the epidu r al s pac e . It b l ock s t h e ne r v es t r a v e r s e the epid u r al s pac e . It c an whi c h c ause hypotension, which is less severe than with spinal analgesia. For prolonged operations, a catheter may be passed into the epidural space for intermittent administration of local anae s thes i a .

12. GENERAL ANESTHESIA : General anesthesia refers to inhibition of sensory, motor and sympathetic nerve transmission at the level of the brain, resulting in unconsciousness and lack of sensation . There are three types of general anaesthesia- spontaneous , controled and assisted. These types are based on whether the patient breathes himself under anaeasthesia, is ventilated artificially, or breathes himself but needs assistance periodically.

13. Inductio n : Anaesthesia may be indused by one of the following techniques- Intravenouos injection of the following:- Thiopentone(2.5%:) short acting(15 to 30 minutes). Methohexitone (1%): ultra-short acting(15 to 30) minutes. Hexobarbitone(10%) : long acting (30 to 45 minutes). Inhalation agents:- Nitrous oxide. Cyclopropane* Halothane Ether* Trichlorethylene Ethyl ghloride Rectal instillation:- thiopentone or paraldehyde is instilled into the rectum through a catheter, as a warmed solution. Alternatively, a rectal suppository may be used. This method of induction is used in children.

14. DISSOCIATIVE ANESTHESIA : Dissociative anesthesia uses agents that inhibit transmission of nerve impulses between higher centers of the brain (such as the cerebral cortex ) and the lower centers, such as those found within the limbic system .

15. GENERAL ANESTHESIA ARE DRUGS THAT BRING ABOUT REVERSIBLE LOSS OF SEN S A T I O N AND CONSCIOUSNE S S. PURPOSES OF ANESTHESIA ANALGESIA ( LOSS OF RESPONSE TO PAIN ) AMNESIA ( LOSS OF MEMORY ) IMMOBILITY ( LOSS OF MOTOR REFLEXES ) HYPNOSIS ( UNCONSCIOUSNESS) PARALYSIS ( SKELETAL MUSCLE RELAXATION )

16. INHALATIONAL ANAESTHESIA Inhalational anesthesia is achieved through airway tract by facemask, laryngeal mask or endotracheal tube agent used is a gas like nitrous oxide or volatile vapor like chloroform, ether, or flothane. - Inhalational anesthesia depresses the brain from up [cortex] to down [the medulla] by increasing dose.

17. 1 . INHA L A T I O NAL ( A ) GASES NITROUS OXIDE A colorless gas with a slightly sweetish odor prepared by heating ammonium nitrate . It produce light anesthesia without significant depression of respiration or vasomotor center . It h a s t he d i s a d va n ta g e t h a t it pr o d u ces li g ht a n est h es i a a n d t h e ref o re can only be used along anesthesia .long term exposure ( like in staff of operation theater ) to low dose can impair DNA synthesis which may result in fetal abnormalities when such staff become pregnant. ( B ) LIQUIDS ETHER- Is a colorless volatile liquid . It is a potent and reliable anesthetic ,good analgesic ,muscle relaxant and d o es n o t d e pr e ss car d i o vasc u l a r a n d res p ir a tory fu n ction in t h e ra p e u tic doses.

18. HALOTHANE Is c o l o rl e ss vo l ati l e l i q u id w ith a s w e e t o d or . It is non irritant and non inflammable Induction is smooth and rapid in 2-5 min surgical anesthesia can be produced ENFLURANE AND ISOFLURANE saf e r They are metabolized to a lesser extent then halothane - therefore regarding the liver toxicity They do not sensitize the heart to adrenaline DESFLURANE AND SEVOFLURANE Are newer agent which bring about very rapid induction and recovery because of low solubility in blood but they too have some disadvantages desflurane is pregnant -may induce coughing and some times laryngospasm .

19. O X YGEN IN ANES T HESIA ` o xy g e n sh o u l d be a d d e d ro u tin e ly t o i n h a l a tion a g e n ts t o pr o tect a g a i nst hypoxia ( especially when halothane is used ) when O2 is not available ,ether is the safer agent for maintenance of anesthesia. INTRAVENOUS ANESTHESIA Iv anesthesia allow an extremely rapid induction because the blood concentration be raised rapidly -in few second there is loss of consciousness Inducing agents Th i op e ntone s od i um Proprofol D i ssoci a tive a nesthes i a ketamine N euro l eptana l g e s ia fentanyl + droperidol Benzodiazepines diazepam , lorazepam , midazolam

20. THIOPENTONE SODIUM is used for induction of anesthesia prior to administration of inhalation anesthesia . A . PROPO F OL Is an oily liquid . It is used for induction and maintenance of anesthesia for short procedures of up to 1 hours duration. B. DISSOCIATIVE ANESTHESIA KETAMINE K e tami n e h y dr o ch l or i de giv e n slow iv pr o d u ces diss o ci a tive a n est h es i a w ith i n 3-5 min which lasts for 10-15 min after a single injection .premedication with atropine is needed . C . NEUROLEPT ANALGESIA FENTANYLE + DROPERIDOL A combination of a neuroleptic ( droperidol ) with an analgesia ( fentanyl ) it last s for 30-40 min . It is employed for endoscopies , burn dressing , angiographies ,and other diagnostic and minor surgical procedures .

21. S T AGE OF GER N AL A N E S T H E S IA Stage of analgesia Is from the beginning of inhalation of the anesthetic to consciousness . Stage of delirium the stage is from loss of consciousness to beginning of surgical anesthesia . It may be associated with excitement shouting ( speak with very loud voice ) crying and violent behavior. Stage of surgical anesthesia the h a s 4 p l a n es .as a n est h es i a p a sses t o d e e p e r p l a n es , res p ir a tory d e pr e ssi o n is seen ,there is gradual loss of reflexes and relaxation of skeletal muscle . depression – cessation of 4. Stage of medularly paralysis is seen only with overdose . It is the stage of medullary breathing circulatory failure and death may follow.

22. I. Analgesia stage Patient conscious Spontaneous respiration Reflexes present Possible small surgery procedures like dressing change in burns II. Excitation stage Possible uncontrolled movements, vomiting Increase in respiratory rate III. Anesthesia for surgery It begins with lack of lid reflex 4 sub stages Airway opening necessary Possible surgery except for abdominal opening if no relaxants are used Possible end tracheal intubation IV. intoxication, overdosing Respiratory arrest If anesthesia not discontinued possible cardiac arrest

23. L o cal a n est h es i a are dr u g s are us e d th a t t he bl o ck n e rve co n d u ction w h e n applied locally to nerve tissue in appropriate concentration . There action is completely reversible Local anesthesia – the administration of an anesthetic agent to one part of the body by local infiltration or topical application. It is usually administered by the surgeon. Used for minor procedures if the patient’s cooperation and the condition warrants its use. Local anaesthetic agents can be defined as drugs which are used clinically to produce reversible loss of sensation in a circumscribed area of the body. Drugs include Beta-adrenoceptor antagonists, opioid analgesics, anticonvulsants and antihistamines. Local anaesthetics can be divided into two groups on the basis of their chemical structure: amides : Lignocaine, prilocaine and bupivacaine esters : Amethocaine, benzocaine, cocaine e.g., amethocaine lozenges for the oropharynx, cocaine for nasal surgery. Most blocks take 5 – 20 minutes to work.

24. C L A S SIFI C A TION OF LO C AL A N E S T H E S IA A. INJECTABLE SHORT-ACTING PROCAINE ,CHLOROPROCAINE INTERMEDIATE –ACTING - LIGNOCAINE , PRILOCAINE LONG-ACTING – TETRACAINE ( AMETHOCAINE ) , BUPIVACAINE , DIBUCAINE , ROPIVACAINE , ETIDOCAINE. B. SURFACE ANESTHESIA LIGNOCAINE ,COCAINE , TETRACAINE, BENZOCAINE, OXETHAZAINE.

25. MEC H E N ISM OF A C TION PREVENT THE GENRATION AND THE CONDUCTION OF NERVE IMPULSES .THE PRIMARY MECHENISUM OF ACTION IS BLOC K ADE OF VO LT AGE -G A T E D SO D IUM CHANNELS .

26. Regional Anesthesia – is broadly defined as a reversible loss of sensation in a specific area or region of the body when a local anaesthetic is injected to purposefully block or anaesthetize nerve fibres in and around the operative site. Commonly R.A techniques include: Spinals (subarachnoid block), epidurals (extradural space) , caudals, and major peripheral nerve blocks. The subarachnoid, epidural or plexus block are called R E GI O N A L A N A E S T H E SIA Some called it regional analgesia as patient is conscious. Some use sedative with regional analgesia to be anaesthesia. Local anaesthesia means block of peripheral nerve or tissue infiltration as in lipoma ( slow growing fat cell in a thin fibrous capsule usually found just below the skin ), circumcision, teeth, eye even craniotomy

27. HYPERSENSITIVITY REACTION - INCLUDED SKIN RASHES ,DERMATITIS , ASTHAMA, OR RARELY ANAPHYLAXIS C.N.S - DIZZINESS , AUDITORY AND VISIUAL DISTURBANCE , MENTAL CONFUSION , DISORIENTATION ,ANXIETY , MUSCLE T REMORS, CONV U L S I O NS AND RESPIR A T O R Y F AIL U RE CAN RESULT FROM LARGE DOSES INTRAVENOUS DIZAPAM CONTROLS CONVULSION . C. V .S - HYPO T EN T I O N , B R ADY C AR D IA , AND AR R HYMIAS M A Y BE ENCOUNTERED . RARELY CARDIAC ARREST CAN OCCUR. LOCAL IRRITATION - CAN BE SEEN WITH BUPIVACAINE . WOUND HEALING MAY BE DELAYED

28. MET H ODS OF A N E S T H E S IA 1. Spinal cord: By injection of local drug in sub - arachnoid space in CSF, this must be bellow L 2 Epidural: The drug is injected outside dura [no puncture] to block the nerve roots at its exit from spinal cord. Nerve plexus: Cervical, brachial, lumbosacral Peripheral nerve: Radial, ulna, median, sciatic, femoral, popletial, facial, mandibular. Injection into tissues, skin, subcutaneous.

29. Spinal anesthesia – local anesthetic injected into subarachnoid space at 3rd or 4th lumbar space Too high = affects resp. muscles Headaches - poss. d/t a in CSF pressure at site of needle insertion Spinal Block - subarachnoid membrane (2nd layer of cord) Epidural Block - outer covering of spinal cord (dura mater) Caudal Block - sacrum Saddle Block - Lower end of spinal column - blocks peri area - clients in labor Monitor BP with all of the above

30. Anaesthetic machine. Monitoring system. Oxygen gas supply. Nitrous oxide gas supply. Flow meter Vaporizer specific for every agent Mechanical ventilator Tubes for connection. Pulse, ECG Blood pressure Oxygen saturation. End tidal CO2 Temperature Urine output, CVP, EEG, bispectral index, muscle tone, ECHO, drug concentration N e ed for 2 impo tools A n est h etic machine monitoring

31. PREPERATION : the suction machine should be checked. Solution catheters and tips are arranged for. The working of the operation table is checked, especially the mechanism of lowering the head end. Nasogastric tubes are kept on the trolly. Resuscitation equipment is checked- O2 cylinder face mask, ambu valve, bag laryngoscope endotracheal tubes drugs: atropine, adrenaline, sodium bicarbonate, mephentermine, dopamine, hydrocortisone, pronethazine. monitoring equipment is checked, e.g. cardioscope with defibrillator, pulse oximiter, capnometer etc.

32. MAINTENANCE: Components of the anaesthesia are anagesia and amnesia . The former is important, because the patient must not feel any pain. The later is important because the patient must not recall any events at the time of the operation. Analgesia is provided by nitrous oxide, trichlorethylene, ether cyclopropane or pethidine. Sleep is achieved with thiopentone, nitrous oxide or cyclopropane. Controlled general anaesthesia needs endotracheal intubation.

33. The vocal cord are paralysed for intubation with suxamethonium or d-tubocurarine. Muscles relaxation for artificial ventilation is achieved with intermitlent administration of suxamethonium , or long acting muscle relaxants like gallamine or d- tubocurarine. The action of last two drugs are reversed at the end of the ope r ation with neo s tigm i n e . A t ropine has to be administered prior to neostigmine to reduce cardiac slowing, and profuse bronchial and salivary secretions produced by neostigmine as a side effect