Conducted by: Ms.Monika Williams Clinical instructor Army college of nursing Anaesthesia &
(“Anaesthesia is one of the pillars of surgery”)
Anaesthsiology : A naesthsiology It is that branch of medicine which is concerned with the administration of anesthetics & the management of the patient under anesthesia Anaesthesia : A naesthesia It is the loss of sensation or feeling or consciousness. Artificial anesthesia is production by a number of agents capable of bringing about partial or complete loss of sensation. It Is deliberately induced to reduce sensation of pain & to achieve adequate muscle relaxation for performing some painful invasive procedures such as investigation & surgery. Anaesthetic : A naesthetic Who is also known as anesthesiologist . He is a doctor or a person specially trained in administering anesthesia . Types of anaesthesia: T ypes of anaesthesia Anesthesia may be of various types; The classification is given below: GENERAL ANAESTHESIA PARTIAL ANAESTHESI A a) General Anaesthesia : a) G eneral Anaesthesia In general anesthesia the whole body is anaesthetized. The brain is affected & the pt becomes unconscious. Anesthetic agents cause absence of pain sensation & muscle relaxation over a entire body & unconsciousness. Cont………d: C ont ………d The anesthetics producing general anesthesia is administered by different routes such as: By inhalation By intravenous By rectal route. General Anaesthesia : G eneral Anaesthesia General anesthesia is the induction of a state of unconsciousness with the absence of pain sensation over the entire body, through the administration of anesthetic drugs. G.A is induced by the following: Inhalation Anesthetics Neuromuscular blockers or muscle relaxants I/V Anesthetics a) Inhalation Anaesthesia : a) Inhalation Anaesthesia These are gases or volatile liquids that produce general anesthesia when inhaled by the pt. The mechanism of action of the inhalation anesthetics is that these involves the uptake of the gases in the lipid bilayer of cell membrane & have interaction with the membrane proteins which inhibits the nerve impulses. Cont……..d: These agents are normally used with Pre- Anesthetic medication includes sedatives & Tranquilizers medication to reduce anxiety & to promote rest & relaxation. Inhalation anesthetics can further be divided as: VOLATILE LIQUID ANAESTHETIC GASEOUS ANAESTHETIC C ont ……..d A) VOLATILE LIQUID ANAESTHETIC : A) VOLATILE LIQUID ANAESTHETIC This volatizes or evaporates easily to produce vapors which are mixed with oxygen & nitrous oxide that are inhaled by the pt. Volatile liquid anesthetics are: Diethyl ether Halothane Enflurane Methoxyflurane a) Diethyl Ether : a) D iethyl Ether It is a clear volatile inflammable fluid which is administered by open drop method of inhalation. It produces anesthesia when vapors are inhaled. It causes adequate muscle relaxations that is suitable for surgery. The advantages of this anesthetics has a wide range of safety B/W the dosage. Cont……….d: C ont ……….d This anesthetic agent causes irritation to respiratory mucous membrane ,increases respiratory secretions ,causes nausea & vomiting & increases blood glucose level. Because of these advantages , it is rarely used these days. 2) Halothene : 2) H alothene This agent is also known as flurothene. This is potent ,non inflammable & can be administered by vaporizers. It is easy to administer ,allows rapid induction of anesthesia. This also causes less postoperative nausea & vomiting. Cont………..d: C ont ………..d It is administered by one drop method : it is dropped slowly on 8 layers of gauzes pieces placed over pt’s nose & mouth. O2 is delivered through a mask. Care should be taken that the fluid does not enter the eye If that happens the eyes are to be washed immediately with sterile or plain water. DISADVANTAGE : this agent provides poor muscular relaxation abdominal muscle & has undesirable affect on liver. 3) Enflurane : 3) Enflurane This is also known as “ Enthrane ’’. It is an inhalation vaporizer. It is non inflammable. It causes slow induction of anesthesia & also causes slow emergence out of anesthesia. this causes excellent muscular relaxation in addition to effective anesthesia. It causes post anesthetic nausea & vomiting. It also causes shivering when comes out of anesthesia. It may also causes respiratory depression. 4) Methoxyflurane : 4) M ethoxyflurane This is also known as PENTHRANE . it is an inhalation vaporizer ,non inflammable ,causes good muscle relaxation acts as well as effective anesthetic agent. This drug causes renal damage. Because of this disadvantage ,this anesthesia agent is not used these days. GASEOUS ANESTHETIC : GASEOUS ANESTHETIC Introduction : I ntroduction This produces anesthesia when the gas is inhaled . This is always given with in combination with o2. These substances when inhaled ,enter the blood through coronary capillaries & when it is sufficient concentration it cats on the cerebral centers to produces loss of consciousness & loss of sensation. When the administration of anesthetic is discontinued the vapor gas is eliminated by lungs. Following gaseous anesthetic agents Nitrous oxide Cyclopropane a)Nitrous oxide: It is colorless ,odorless gas. This is a weak anesthetic agent which is usually administered with the combination of O2. This produces G.A. Advantages: the onset of anesthetic effect & the emergence out of anesthesia are rapid. It has pleasant smell. It causes least disturbances to the body. This anesthetic agent is used for short surgical procedure. Disadvantage : it is weak anesthetic agent . a) Nitrous oxide b) Cyclopropane: It is colorless gas. This anesthetic agent is administered by inhalation. It is more powerful than nitrous oxide. It can produce anesthetic effect in concentration of 80-85% O2. It is non irritating but it may cause respiratory depression or disorder of heart rate. Because of these disadvantages it is used frequently. b) C yclopropane b) Neuromusculo blockers or mucle relaxants : These drugs produce muscle relaxants during surgery. These groups of drugs interfere with the passage of impulse from the motor nerve to the skeletal muscles. Anesthetic effect occurs after 1 to 1 ½ minute or 60 to 90 seconds of the administration of the anesthetic agent. It provides light anesthesia & the effect remain for 3-5 minute. The neuromuscular blocking agents are : Tubocurarine Metocurine succinylcholine b) Neuromusculo blockers or mucle relaxants c) Intravenous Anaesthetic : These are the sedatives hypnotics drugs that produces anesthesia in large dose. The most commonly used I/V anesthetics are Barbiturates such as Thiopental sodium or pentothal. It is short acting & leads to unconsciousness in 30 seconds. It is used for short surgical procedures. Such as eye surgery It Is also used for rapid induction of anesthesia It does not cause dizziness buzzing or roaring sensation to ears It is easy to administer. c) I ntravenous Anaesthetic Cont………….d: There is little post anesthetic nausea & vomiting. It is also non explosive . But it is not indicated for children having small veins. C ont ………….d Other drugs as I/V Anaesthetics : Narcotics as Morphine ,Mephidrine ( Demerol) Tranquilizer such as diazepam ( calmpose) & valium Muscle relaxant such as Queline or anectine. Sometimes these anesthetic agents are administered by I/M route too. O ther drugs as I/V Anaesthetics II) PARTIAL ANAESTHESIA: In partial anesthesia ,the part of the body where surgery is intended is anaesthetized. The pt remains conscious in partial anesthesia is achieved by I/M or intra spinal injection or by spray to the skin surface or by applying ointment or gum during tooth extraction. II) PARTIAL ANAESTHESIA Partial anaesthesia is of four types: Local Anaesthesia Regional Anaesthesia Spinal Anaesthesia Topical Anaesthesia P artial anaesthesia is of four types a) d) c) B) d) a) Local anaesthesia : a) L ocal anaesthesia In local anesthesia a specific area in the body is anaesthetized. The anesthesia is achieved by injection or spray of local anesthetic drug into the tissue It block a nerve supplying to a specific site of operation. Cont……….d: C ont ……….d This type of anesthesia is used for a short or superficial operations such as gastrostomy ,tracheostomy ,minor cosmetic surgery ,dental surgery ,eye surgery ,acupuncture etc. Often it is combined with regional block. LOCAL ANAESTHETIC DRUGS : Lidocaine (Xylocaine) Mepivocaine (Carbocaine) Procaine (Novocaine) Tetracaine (Pontocaine) Bupivacaine (Marcaine) Injection of solution in various concentration of 0.5 to 2.0 % is used. A small gauge needle is used to inject a little of anesthetic agent to skin layer. Larger needle is used to infiltrate deeper tissue The effect lasts for 15 mins to 3 hours. LOCAL ANAESTHETIC DRUGS b) Regional anaesthesia : b) R egional anaesthesia it Is a form of anesthesia in which anesthetic agent is injected into a selected region of pt’ body. So that area supplied by nerves is anaesthetized. Pt remain conscious It interrupts the sensory nerve conductivity of any region of the body . Blockage can be of two types : B lockage can be of two types Field block : Block in which encircling the operative field is done by means of injection of a local anesthesia. Nerve block : block in which injection is given in the to the nerves supplying the area. Methods of regional anaesthesia : Brachial plexus block : this produces anesthesia of arms. Para vertebral anesthesia block : this produces anesthesia of nerve supplying chest & abdominal walls &extremities. Transsacral (caudal )block : this produces anesthesia of perineum & occasionally of lower abdomen. this is used for obstetrics operations or delivery of baby. M ethods of regional anaesthesia c) Spinal anaesthesia :
c) S pinal anaesthesia The anesthetic agent is introduced into the spinal canal which affects the
below brain or the peripheral system. Anaesthesia is produced by blocking spinal ganglion & nerve root in spinal cord.
Uses of spinal anaesthesia : U ses of spinal anaesthesia Operation in lower abdomen Obstetric Delivery Rectal surgery Cystoscopy Operation on lower legs Drugs : procaine ,tetracaine ,Dibucaine ,Xylocaine. Spinal anesthesia : advantages It is easy to administer spinal anesthetic agent. It is comparatively inexpensive The onset of anesthesia is rapid & act as good muscle relaxant. After administration there is marked fall in BP. Presence of nausea & vomiting Partial or complete respiratory paralysis may also occur so pulmonary resuscitation equipments should be ready to handle the emergency Spinal anesthesia disadvantages Procedure : A spinal puncture is made with aseptic precautions & the drug is injected in solution through needle after the drug is administered the pt is placed on his or her back In a few mins anesthesia appears first on the toes ,then to legs & then on the perineum & the abdomen. P rocedure Methods to administer spinal Anaesthesia : SERIAL OR CONTINOUS ANAESTHESIA: - method for maintaining regional nerve block. Tip of plastic catheter may be left in the subarachnoid space during operation. So that more anesthetic agents can be injected if needed. But there may be complication such as headache. M ethods to administer spinal Anaesthesia b) EPIDURAL OR PERIDURAL ANESTHESIA:: It is regional anaesthesia resulting from injection of an aesthetic into the epidural space of the spinal cord. sensation is lost in the abdominal and genital and pelvic areas; used in childbirth and gynaecological surgery. ADVANTAGE: it does not cause headache. DISADVANTAGE: it is difficult to administer the drug into the epidural space. b) EPIDURAL OR PERIDURAL ANESTHESIA : d) TOPICAL ANAESTHESIA : Topical anesthesia is produced by applying a local anesthesia or spray directly to the areas involved such as on the skin surface or on the gum during some dental procedures. Topical anesthetic medications must be selected carefully and used in proper amounts in order to prevent harmful reactions. A topical anesthetic mixture containing lidocaine, epinephrine, and tetracaine. d) TOPICAL ANAESTHESIA METHODS OF ADMINISTRATION OF ANAESTHETIC AGENTS : ONE DROP METHOD : This method is used when anesthesia is required for a brief period only for procedures ;like laryngoscope ,Bronchoscopy. Volatile liquid anesthetic such as HALOTHENE is used. This fluid is dropped slowly on 8 layer gauzes & placed over pt’s nose & mouth. O2 is delivered through a mask. care should be taken so that liquid does not enter the eyes. METHODS OF ADMINISTRATION OF ANAESTHETIC AGENTS 2) VAPOURS OR GAS ANAESTHETUC ADMINISTRATION : vapors of gaseous anesthetic mixed with O2 & nitrous oxide. Pt inhales the mixture through mask fitted to nose & mouth. 2) VAPOURS OR GAS ANAESTHETUC ADMINISTRATION c) Endotracheal Anaesthesia : A soft plastic or rubber made Endotracheal tube is introduced into the trachea with the help of laryngoscope. It is introduced through the nose or mouth. The method has many advantages such as : Clear airway can be maintained Minimal danger of respiratory tract obstruction Convenient method of aspirating secretions ,blood from trachea . Care should be taken to prevent injury of mucous membrane ,soft tissue of the lips ,tongue & gums. c) Endotracheal Anaesthesia Position of the pt during Anaesthesia : P osition of the pt during Anaesthesia Normally the anesthesia in dorsal recumbent position. Same position is retained for chest operation & abdominal operation C shaped is assumed for spinal anesthesia. Stages of inhalation anaesthesia : S tages of inhalation anaesthesia The anesthetic period is divided in four stages: Pt passes smoothly from one stage to the another. These stages are divided according to the physical response of the pt to the anesthetic agent that has been administered . Beginning of Anesthesia Stages of Excitement Stages of surgical Anesthesia Stage of Danger a) Beginning of Anaesthesia : As patient breathes anesthesia : A feeling of warmth Dizziness Feeling of detachment Respond slowly to questioning Ringing ,Roaring & Buzzing sensation in the ears Pt is still conscious but is unable to move extremities Noises are sensed exaggerated ( so noise & movement are kept minimum during this period) a) Beginning of Anaesthesia II) STAGE OF EXCITEMENT : It stage is called the stage of excitement. Purposeless muscular activity like struggling & uncontrolled movement of the limbs & the body. Shouting & talking loudly Singing ,laughing & crying loudly Pt may respond violently to auditory stimuli Pupils are dilated but may contact if exposed to light. Pulse is increased Respiration is irregular Pt loses consciousness II) STAGE OF EXCITEMENT Stage-111) Stage of Surgical Aneasthesia : Pt becomes unconscious Pt lies quietly Surgical anesthesia is achieved Pupils are dilated but contract to light Pt’s respiration is regular ,quiet ,shallow & short Pt pulse is normal & volume is good Pt’s skin is pink &slightly flushed Pt’s extremities are relaxed. This stage is maintained throughout the surgery. S tage-111) Stage of Surgical Aneasthesia Stage –IV) Stage of Danger: This stage when too much anesthesia is accidently administered. Respiratory muscles are paralyzed Respiration becomes shallow Pulse weak Pupils widely dilated & fixed ,pupil donot contract to light Cyanosis & complete muscle relaxation take place Death follows S tage – IV) Stage of Danger Measures to handle the Danger Stage : The anesthesia must be immediately discontinued Artificial respiration & ventilation is applied O2 is administrated & by mask method Stimulants administered to revive the pt. M easures to handle the Danger Stage Other physioogical changeswhich occur during anaesthesia are as follows: excessive secretions of mucus & saliva occur & this can be minimized by pre-operative administration of atropine & frequent suctioning to remove excessive secretions. Vomiting & regurgitation occurs- these can be prevented by keeping the stomach empty preoperatively. Pt should remain nil by mouth for 10-12 hours prior to surgery O ther physioogical changeswhich occur during anaesthesia are as follows Cont………d: Gagging might occur which may be prevented by keeping pt’s head turned to one side or by lowering the head end. Pt’s temperature falls – pt should be kept covered by blanket to keep the pt warm & prevent chilling. Asphyxia may be caused by spasm of the vocal cord Aspiration of vomitus ,saliva ,blood or any foreign body . Asphyxia can be avoided by use of Endotracheal tube with an inflated cuff. C ont ………d Pre-operative check up by anaesthesiologist : To explain briefly to the pt about anesthesia ,its necessity ,its stage ,procedure ,its after effects etc To remove from the pt ‘s mind fear ,uncertainty & anxiety of anesthesia To obtain maximum cooperation from the pt during anesthesia To examine the pt’s condition of lungs & pulmonary status To assess the pt’s circulatory status & condition of the heart To enquire about pulmonary infection suffered by the pt To assess general physical condition To monitor the pt’s cardinal signs To make an overall assessment of pt’s preoperative ,pre anesthetic preparation. P re-operative check up by anaesthesiologist Slide 54: Thanks