Life Academy with Anesthesia IQ 2024 PDF

  Anesthesia & Anesthetic drugs BY LECTURER Qutepa Natiq AL-hashmy Bachelors Anesthesa and ICU Work in IBH For Cardiac Center...

  Anesthesia & Anesthetic drugs BY LECTURER Qutepa Natiq AL-hashmy Bachelors Anesthesa and ICU Work in IBH For Cardiac Center    After reading this chapter you should understand the principles of: The role of the preoperative assessment clinic Which investigations are necessary prior to anaesthesia Taking a history and examine, paying particular attention to those features that may impact on the conduct of anaesthesia The basic pharmacology of the drugs used for induction and maintenance of anaesthesia and neuromuscular blockade. Calculating the maximum safe dose of drugs for a given patient and procedure Under supervision, preparing the correct doses of drugs for induction of anaesthesia Under supervision, preparing the correct doses of drugs for neuromuscular blockade How to use different types of airway equipment  Anesthetic assessment and preparation for surgery. General fact: 1. This role is frequently undertaken Malti personal who may take a history, examine the patient, and order investigations according to the local protocol. The primary aim is to identify those patients at low risk of complications during anesthesia and surgery. 2. Have a coexisting medical problem that is well controlled and does not impair daily activities, such as hypertension/DM. 3. Present and past medical history for the anesthetist, the patient’s medical history relating to the cardiovascular and respiratory systems are relatively more important. 4. Ischemic heart disease; heart failure; hypertension; valvular heart disease; conduction defects, arrhythmias; peripheral vascular disease, previous deep venous thrombosis (DVT) or pulmonary embolus (PE). 5. In near MI, Elective surgery may only need to be delayed by 6–8 weeks. Patients should be asked about frequency, severity and predictability of angina attacks. 6. Both hypertension and hypotension can be precipitated, which increase the risk of myocardial and cerebral ischemia. 7. Considering staging of HT. 8. COPD; asthma; infection; restrictive lung disease. Patients with preexisting lung disease are at increased risk of postoperative chest infections. 9. If an acute upper respiratory tract infection and LRTI is present, anesthesia and surgery should be postponed unless it is for a life‐threatening condition. 10. Other important considerations: Family history, Drug history and allergies, Previous anesthetics and operations, social history. 11. The fasting is high important in anesthesia job, The Royal College of Anesthetists and AAGBI recommend 2 hours for clear fluid / breast milk 4 hours formula milk 6 hours for hard food. 12.Examine airway to assess DETT (Mallampati score). 13.3 make sure: - 14.Make sure the chest clear (by auscultation) and no evidence of add sound. 15.Make sure you see the all investigation is mandatory, CBC.RFT.Virals scan, LFT, CXR, or author tests. 16.Make sure take anesthesia risk (Obtaining informed consent). Types of Anesthesia:  General fact for type of anesthesia: 1. Depending on Protocol policy of hospital or center. 2. Risk/benefit consideration. 3. Put in mind indications of each type of anesthesia. 4. Put in mind planer for anesthesia. Drugs and fluids used during anesthesia. The general facts: 1. Anesthesia team have to be familiar with a wide range of drugs, those directly associated with anesthesia. 2. Any medications taken by a patient that may impact upon anesthesia. 3. Unlike in most other branches of medicine, drugs associated with anesthesia are almost always given parenterally, either intravenously or via inhalation, usually produce rapid and profound physiological changes. 4. Many patients will also require intravenous fluids, blood and blood products perioperatively, Cross- Mach and overload fluid risk. In premeditation Modification of pH and volume of gastric contents Patients are starved preoperatively to reduce the risk of regurgitation and aspiration of gastric acid at the induction of anesthesia. certain high‐risk groups may be given specific therapy to try to increase the pH and reduce the volume of gastric contents: women who are pregnant, patients who require emergency surgery, patients with a hiatus hernia, patients who are morbidly obese. 1- ranitidine (H1 antagonist): 150mg orally 12 hours and 2 hours preoperatively. 2- omeprazole (proton pump inhibitor): 40mg 3–4 hours preoperatively. 3- metoclopramide: 10mg orally preoperatively – it increases both gastric emptying and lower esophageal sphincter tone. Antiemetics, these drugs are often given as a premed to try and reduce the incidence of postoperative nausea and vomiting (PONV) The Intravenous anesthetic drugs This group of drugs is most commonly used to induce anesthesia. After IV injection, these drugs are carried in the bloodstream into the cerebral circulation. They are very lipid soluble and quickly cross the blood–brain barrier, resulting in loss of consciousness. Following a single bolus dose, the drug undergoes redistribution to other tissues (initially the muscles and then fat), the plasma and brain concentrations fall and the patient consciousness. All drugs used for induction cause depression of the cardiovascular and respiratory systems. The Total intravenous anesthesia TIVA When IV drugs alone are given to induce and maintain anesthesia, the term ‘total intravenous anesthesia’ (TIVA). For a drug to be of use in maintaining anesthesia, it must be rapidly metabolized to inactive substances or eliminated to prevent accumulation and delayed recovery. infusion of propofol is the only technique used. The Neuromuscular blocking drugs Depolarizing neuromuscular blocking drugs These work by preventing acetylcholine interacting with the postsynaptic (nicotinic) receptors on the motor endplate on the skeletal muscle membrane. Muscle relaxants are divided into two groups and named to reflect what is thought to be their mode of action. Suxamethonium This is the only drug of this type in regular clinical use. It comes ready prepared (50mg/mL, 2mL ampoules). The dose in adults is 1.5mg/kg IV. After injection, there is a short period of muscle fasciculation as the muscle membrane paralysis in 40–60 seconds. This rapid onset makes it the drug of choice to facilitate tracheal intubation in patients likely to regurgitate and aspirate. As part of a technique called a rapid‐sequence induction. suxamethonium has no direct effect on the cardiovascular, respiratory or central nervous systems. Bradycardia secondary to vagal stimulation is common after very large or repeated doses, and can be avoided by pretreatment with atropine. Pseudocholinesterase deficiency is rare issue deficiency leading prolong apnea need MV in recovery stage.  Non‐depolarizing neuromuscular blocking drugs These drugs compete with acetylcholine and block its access to the postsynaptic receptor sites on the muscle but do not cause depolarization. Onset of aching 1.5–3 minutes. Neostigmine + Atropine (anticholinesterase) A fixed dose of 2.5mg intravenously is used in adults. Its maximal effect is seen after approximately 5 minutes and lasts for 20–30 minutes. It is given concurrently with either atropine 1.2mg or glycopyrrolate 0.5mg. Sugammadex due cost same time never seen. The Analgesic drugs Analgesic drugs are used as part of the anesthetic technique to reduce the autonomic response to surgery, allow lower concentrations of inhalational or intravenous drugs to be given to maintain anesthesia, and try to minimize immediate postoperative pain. Opioid analgesics This term is used to describe all drugs that have an analgesic effect mediated through opioid receptors. Overdose due opioid is happened special in poor experience personality, IF happen ABC system most be apply to regulations and cover issue: - Supported ventilation using a bag‐valve‐ mask with supplementary oxygen. The effects of the opioid can be pharmacologically reversed (antagonized). Naloxone (0.4mg) is diluted to 5mL with 0.9%.  The Inhalation agents Although these drugs can be used to induce anesthesia, they are most commonly used to maintain anesthesia. A controlled amount of the vapor that is produced is added to the fresh gas flow (oxygen and air or nitrous oxide). Two concepts that will help in understanding the use of inhalational anesthetics: solubility and minimum alveolar concentration (MAC). Breathed by the patient. Once in the lungs, the vapor diffuses into the pulmonary capillary blood and is distributed via the systemic circulation to the brain and other tissues. The depth of anesthesia produced is directly related to the partial pressure that the vapor exerts in the brain, and this is closely related to the partial pressure in the alveoli. The rate at which the alveolar partial pressure can be changed determines the rate of change in the brain and hence the speed of induction, change in depth and recovery from anesthesia. All the inhalational anesthetics cause dose‐dependent depression of the cardiovascular and respiratory systems. Solubility The rate of change of depth of anesthesia is determined by how quickly the partial pressure of anesthetic can be altered in alveoli, and hence the brain. If an agent is insoluble in blood (for example, desflurane), a smaller amount will exert a higher blood and brain partial pressure. Therefore, an increase in depth of anesthesia can be achieved more quickly. Other factors that determine the speed at which the alveolar concentration rises include the following: 1-A high inspired concentration 2- Alveolar ventilation 3-Cardiac output: if high, this results in a greater pulmonary blood flow and increasing uptake, thereby lowering the alveolar partial pressure. If low, the converse occurs and the alveolar concentration rises more rapidly Minimum alveolar concentration Minimum alveolar concentration is the concentration required to prevent movement following a surgical stimulus in 50% of subjects. Compounds with a low potency (such as desflurane) will have a high MAC; those with a higher potency (such as isoflurane) will have a lower MAC. We have factors effect of MAC. Blood/ Gas partition coefficient  The Airway Management Airway equipment Key points: The ability to ensure that a patient has a patent airway at all times is arguably the most important skill that an anaesthesia team possesses. Airway anatomy most be know, mandatorily. The important thing is to know when and how to use a selected range of devices well. The following is a description of most of the commonly available airway equipment; a description of the skills needed to use it safely and successfully. Facemasks These are designed to fit closely to the contours of the face and a gas‐tight fit with the patient’s face is achieved by an air‐filled cuff around the edge. They are almost always single use and are made from transparent plastics, allowing visualization of vomit and misting during successful ventilation, making them popular for use during resuscitation. Oropharyngeal airway These are curved plastic tubes, flattened in cross‐ section and flanged at the oral end. They lie over the tongue and prevent it from falling back into the pharynx. They are manufactured in a variety of sizes and are suitable for all patients, from neonates to large adults. The commonest sizes are 2–4, for small to large adults. Laryngeal mask airway (LMA) This is attached to a tube that protrudes from the mouth and connects directly to the anesthetic breathing system. Around the perimeter of the mask is an inflatable cuff that helps to stabilize it and creates a seal around the laryngeal. A: B: C: Supraglottic airway devices. (a) Disposable LMA. (b) LMA Pro‐SealTM. (c) i‐gelTM Ambo-bag Is equipment usually used in resuscitation period.  Tracheal tubes General Considerations: These are manufactured from plastic (PVC). Single use to eliminate cross‐infection. Sized according to their internal diameter ID. A standard 15mm connector is provided to allow connection to the breathing system. The tracheal tubes used during adult anaesthesia have an inflatable cuff to prevent leakage of anesthetic gases. Cuff use to also to prevent aspiration of any foreign material into the lungs. The cuff is inflated by injecting air via a pilot tube, at the distal end of which is a one‐way valve to prevent deflation and a small ‘balloon’ to indicate when the cuff is inflated. B-Reinforced tubes: used when a plain tube A-Stander ETT might kink and become obstructed, e.g. due to the positioning of the patient’s head or as a result of surgical manipulation C-Preformed tubes: used during surgery on the D-Double‐lumen tubes: effectively two tubes head and neck. facing and are designed to take the welded together side by side, with one tube connections and breathing system tubing away extending distally beyond the other. They are from the surgical field used during intrathoracic surgery, and allow the anesthetist to ventilate one lung selectively.  Laryngoscopes (a) Macintosh laryngoscope. (b) McCoy laryngoscope. Note lever on handle to flex the tip. (c) McCoy laryngoscope with tip flexed. (d) Glidescope with view of larynx seen on screen Fiberoptic bronchoscope. A typical difficult airway trolley Intravenous fluids ICF-ECF-ISF FACT: 1-The fluid moves from high concentration to low consideration. 2-50 and 60 percent the body is water. 3- The hydrostatic pressure and osmotic pressure work to moves fluid between component of body fluid. Blood and blood components