Anesthesia slideshare

definition of anesthesia, history , general anesthesia, spinal anesthesia, epidural anesthesia, uses, drug agents, complications and management.

1. hj Dr. Poonam arya BAMS ,MS 2 nd year ( shalya tantra deptt .) skgac kurukshetra

2. Anesthesia : defination . Anesthetic , also spelled  anaesthetic , any agent that produces a local or general loss of sensation, including  pain . Anesthetics achieve this effect by acting on the  brain  or  peripheral   nervous system  to suppress responses to sensory stimulation. The unresponsive state thus induced is known as  anesthesia .  General anesthesia  involves loss of  consciousness , usually for the purpose of relieving the pain of  surgery .  Local   anesthesia involves loss of sensation in one area of the body by the blockage of conduction in nerves.

3. History of Anesthesia The Wood Library-Museum of Anesthesiology (WLM) presents an interactive timeline of the history of anesthesia and the profession of anesthesiology through important milestone people, places, dates and developments. While the use of opium poppy , moha churna , alcohol and other herbal remedies as anesthetics date back to early civilization(described in sushruta samhita ) , the first public demonstration of modern anesthesia was on October 16, 1846 ("Ether Day"). William T. G. Morton and surgeon John Collins Warren made anesthesia history at Massachusetts General Hospital with the successful use of diethyl ether "anaesthesia" to prevent pain during surgery. Since this historic milestone, advancements in anesthesia administration and newer anesthetics led to the medical specialty of anesthesiology in the early 20th century.

4. ANESTHESIA 10 golden rules Mnemonic: ANESTHESIA A: Assessment and preparation of patient. N: Nil per oral. E: Equipment and drugs checked. S: Suction working. T: Tipping table. H: Have a vein open. E: Evaluate vitals. S: Somebody to help.

5. Examination Investigations & Assessment Examination General A general systems examination should identify obvious abnormalities: Cardiovascular system - heart murmur. With the exception of emergency surgery, patients should be haemodynamically stable and their vital signs normal before starting anaesthesia. Respiratory system - abnormal breath sounds. Gastrointestinal system - abdominal masses, previous scars. Musculoskeletal system - skeletal malformations such as kyphoscoliosis . General - local skin infection

6. Airway assessment How easy or difficult it will be to intubate a patient depends on the following points: Are they obese? Do they have a short neck and small mouth? To what extent can they open their mouth? Is there anft tissue swelling at the back of the mouth or are there any limitations in neck flexion or extension?y so Investigations Cbc , blood sugar , blood urea. Serum creatinine , electrolytes, chest x ray , ecg , blood grouping , BT, CT, blood gas analysis, cardic assessment , lft , kft , cross match , ecg , spirometry , pregnancy test .

7. Scoring to assess intubation: Mallampati scoring :

8. Preoperative treatment: Control of respiratory and cardiac disease. Improvement of hb % , if anaemia is present . Preoperative antibiotics are given . Blood should be kept ready for major cases. Starvation for 4 hours for liquids and six hours for solids. Bladder and bowel should be empited to prevent soiling on the operation table . Urinary catheter may be passed and enema may be given . Dantures , jewellery, contact lenses must be removed . Analgesic, anti-emetic , sedative should be given as per requirements.

9. Genral anaethesia It means abolition of all sensation, i.e. Touch, pain , posture and temperature with a state of reversible loss of consciousness. It has got three components ; analgesia , hypnosis , muscle relaxation. Instruments used in GA : The respirator bag valve mask. Anesthesia machine. Oxygen mask. Laryngoscope. Tracheostomy tube. Tuohy needle. Flexible Endoscope. Syringe.

10. 1 Intravenous anaesthetics 2 gaseous anaesthetics - etomidate-lipura (Anaesthetics only) - ketamine (Anaesthetics, A&E, Palliative Care Team and Acute Pain Team only) - propofol (Anaesthetics and ICU only) - propofol-lipura , thiopental sodium and desflurane . Nitrous oxide and cyclopropane . Anaesthetic agents : 3 Inhalational anaesthetics enflurane (Anaesthetics only) halothane (Anaesthetics only) isoflurane (Anaesthetics only) sevoflurane (Anaesthetics only) 4 Muscle relaxants - rocuronium - suxamethonium (Anaesthetics, ICU and Neonatal directorate only) - vecuronium (Anaesthetics, ICU and Neonatal directorate only) - edrophonium ,neostigmine, doxapram

11. Stages of anaesthesia: Guedel's classification , introduced by  Arthur Ernest Guedel  in 1937, [22]  describes four stages of anaesthesia. Despite newer anaesthetic agents and delivery techniques, which have led to more rapid onset of—and recovery from—anaesthesia. Stage 1 , called I nduction , is the period between the administration of induction agents and loss of consciousness. Patients can carry on a conversation at this time. Stage 2 called E xcitement stage , is the period following loss of consciousness and marked by excited and delirious activity. During this stage, the patient's  respiration  and  heart rate  may become irregular. In addition, there may be uncontrolled movements, vomiting,  suspension of breathing , and  pupillary dilation . Because the combination of spastic movements, vomiting, and irregular respiration may compromise the patient's airway, rapidly acting drugs are used to minimize time in this stage and reach Stage 3 as fast as possible.

12. Stage 3 , also known as  surgical anaesthesia , the skeletal muscles relax, vomiting stops, respiratory depression occurs, and eye movements slow and then stop. The patient is unconscious and ready for surgery. This stage is divided into four planes: The eyes roll, then become fixed; Corneal and laryngeal reflexes are lost; The pupils dilate and light reflex is lost; Intercostal paralysis and shallow abdominal respiration occur. Intercostal paralysis and shallow abdominal respiration occur. Stage 4 , also known as  overdose , occurs when too much anaesthetic medication is given relative to the amount of surgical stimulation and the patient has severe  brainstem  or  medullary  depression, resulting in a cessation of respiration and potential cardiovascular collapse. This stage is lethal without cardiovascular and respiratory support.

13. Premedication : for reduce vomiting – promethazine 12.5mg. for sedation& anxiety – pethidine 50mg/. Induction - Patient is preoxygenated with 100% oxygen for 3 minutes then induced with Iv thiopentone, given 4-5mg/kg. Patient loses consciousness. Induction is maintained by 67% nitrous oxide and 33% oxygen. Scoline is given IV relax muscles so as to facilitate endotracheal intubation. Once intubated, ventilation can be either controlled using one muscle relaxants or spontaneous using a volatile anaesthetic agent. Reversal is done using neostigmine and atropine or glycopyrrolate.

14. complications of general anaesthesia Post operative care Pain, hypoxia , pneumothorax. Nausea and vomiting - up to 30% of patients. Damage to teeth. Sore throat and laryngeal damage. Anaphylaxis to  anaesthetic  agents - approximately 1 in 3,000. Cardiovascular collapse. Respiratory depression Mendel son's syndrome. Pulse, temp. ,Bp chart. Level of consciousness. Urine output. Care of respiratory system Oxygen therapy. Pulse oxymetry. Monitoring of the patient. Cardiac monitoring. Blood gas analysis in case of patient on ventilator. Serum electrolyte assessment.

15. Regional anesthesia is the use of local anesthetics to block sensations of pain from a large area of the body, such as an arm or leg or the abdomen. Regional anaesthesia allows a procedure to be done on a region of the body without your being unconscious. Advantages: technically simpler. GA is avoided & consciousness is retained. Drugs used- cocaine, procaine, lignocaine- amino esters . Lignocaine, prilocaine, bupivacaine ,ropivacaine- amino amides. Topical anasthesia : it is defined as superficial loss of sensation in conjunctiva, mucous membranes, or skin, produced by direct application of local anaesthetic solutions, ointments, gels or sprays. Infiltration block- direct inj. of local anaesthetic under the skin for small procedure. Field block : it is achieved by blocking the entire field of excision where lesion is located. Nerve block , or neural blockade, is a method of producing anesthesia — a loss of feeling used to prevent or control pain. Nerve blocks can be surgical or nonsurgical.

16. Spinal anaesthesia  (or  spinal anesthesia ), also called  spinal block ,  subarachnoid block ,  intradural block  and  intrathecal block , [1]  is a form of neuraxial   regional anaesthesia  involving the  injection  of a  local anaesthetic  or opioid into the  subarachnoid space , generally through a fine  needle , usually 9 cm (3.5 in) long. Types-caudal (up to L5). Low spinal ( up to L1). Mid spinal(up to T10). High spinal( up to T6). Unilateral spinal.

17. Advantages: Disadvantages& complications economical. hypotension reduces the bleeding. Adequate relaxation is achieved. Respiratory complications are less. Failure of the  spinal . Pain during the injection. Low blood pressure. Headaches. Itching. Difficultly passing urine. Backache Complication - meningism & infection. Bradycardia . Nausea and vomiting. Transient neurological  symptoms  (lower back pain with pain in the legs). Post- dural -puncture headache.

18. Epidural anasthesia : It is a potential space between Dura anteriorly and ligamentum flavum posteriorly which has got negative pressure inside. It extends from foramen magnum to sacral hiatus. Toughy needle is used for epidural anaesthesia. Once the needle is in space there will be sudden indrawing of air and saline drop. A epidural catheter is placed in the space and fixed . 2% xylocaine with adrenaline or 0.5% bupivacaine is injected into space to achieve anathesia up to desired level. advantages : it can be used for continuous repeated prolonged anaesthesia. It can be used for postoperative analgesia. It can be kept for several days.

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