Anesthesia and Pain Management MUDr. L. Dadák, ARK, FNUSA https://is.muni.cz/auth/el/1411/zima2011/VSAL091/ My goal: lunderstand basic concepts of general and regional anesthesia llearn basic skills of airway management lanatomy of regional anesthesia (SA, EPI) lanesthesia of children .. and if you would like, more … How to get credit?? Lectures Literature : Larsen, Miller, Barash Anesthesia Short test Simulation (Airway management drill) OR – voluntary intership Oral Exam > Topics for oral exam •Anatomy of airways + physiology of breathing •Physiology of circulation (cardiac output) •Monitoring •Pharmacology •ASA I patient and GA, premedication; •Airway management –Rapid sequence of induction = technique, indications –Difficult ventilation / intubation •Malignant hyperthermia •Acute, chronic pain •Anatomy of spinal column – SA, EPI IS.MUNI - Bookmarks History 4Opium (Egypt, Syria) –Hippokrates 400 BC ease pain 41555 Andreas Vesalius - arteficial ventilation through tube between vocal cords, ventricular fibrilation (animals) 41546 Valerius Cordus - ether – oleum vitreolum dulce 41547 Paracelsus - analgetic effect of ether 41646 Severino - cryoanaesthesia – Napoleon's wars - Larey 41773 N2O Joseph Priestley (1733-1804) 41774 oxygen 41779 Humphry Davy - anaesthetic effect of N2O Surgery before modern Anesthesia Surgical procedures were carried out prior to the introduction of anesthetics. The key to success was the speed of the procedure, with successful amputations lasting 30 seconds. Strong assistants and restraints were frequently required. Alternatively, decreased cerebral perfusion via bilateral carotid compression was used to decrease sensation during the procedure. Importantly, surgical procedures were associated with significant risk of death and, at a minimum, severe pain. The development of anesthesia was heralded as one of the great advances of modern medicine, in that it allowed surgery to advance. Beginning of GA 4October 16th 1846 ether general anaesthesia Boston dentist William Thomas Green Morton to Gilbert Abbott (tumor of mandibule) 4February 6th 1847 Prague - first Czech ether anaesthesia - Celestýn Opitz 41895 direct laryngoscopy Alfred Kirstein in Berlin. –1920 direct laryngoskopy to clinical praxis Magill and Rowbotham Ether After ether l1847 – chloroform – obstetrics anesth. l1884 – cocaine – eye, .. mucosa l1885-99 – cocaine “spinaly” l1950's – halothan l1960's – enflurane, isoflurane l1994 – sevoflurane Ideal anesthetic ltemporary disable function of neurons lno influence on breathing, circulation lsafe, cheap, non-toxic,... lDoes not exist. Anesthesiology is a jung discipline (160y) dealing with •The preoperative, intraoperative and postoperative evaluation and treatment of patients who are rendered unconscious and/or insensible to pain and emotional stress during surgical, obstetrical, therapeutic and diagnostic medical procedures; •The protection of life functions and vital organs (brain, heart, lungs, kidneys, liver, endocrine, skin integrity, nerve) under the stress of surgical and other medical procedures; Anesthesiology •Monitoring and maintenance of normal physiology during the perioperative period; •Diagnosis and treatment of acute, chronic and cancer-related pain; •Clinical management of CPR; •Evaluation of respiratory function and application of respiratory therapy; •Management of critically ill patients; •Conduct of clinical research; •Teaching personnel involved in perioperative care GUIDELINES FOR PATIENT CARE IN ANESTHESIOLOGY, ASA 1967 General Anesthesia - Definition 4arteficial intoxication, controled coma 4reversible 4drug-induced loss of consciousness, felling, pain. „No reaction“ to stimuli 4allow therapy (surgery, electroshock) 4allow diagnostic method (CT, MRI) Patient + GA 4preoperative anaest. visit, informed consent 4premedication 4venous line 4monitoring 4induction 4(airway protection) 4maintenance 4(extubation) 4treatment of postoperative pain record of GA ASA Physical Status = risk I Healthy patient 0,06% II Mild systemic disease, no functional limitations hypertension, smoker, mild asthma 0,47% III Severe systemic disease- definite functional limitation coronary disease, COPD, DM, CHF, renal failure 4,39% IV Severe systemic disease that is a constant threat to life unstable angina, burn with septic shock 23,48% V Moribund patient not expected to survive 24 hours with or without operation patient with extensive bowel infarction, polytrauma 50,8% Preoperative tests as a component of the preanesthesia evaluation, may be indicated to: 1) discovery a disease or disorder which may affect perioperative anesthetic care, 2) verification of an already known disease, disorder, medical or alternative therapy which may affect perioperative anesthetic care, 3) formulation of specific anesth. plans Will I change something if the resust is ...? Preoperative examination 4history (GA, RA, complications) 4physical examination (neck, back) 4laboratory: blood cells, ions, urea, creatinin, glucose, AST, ALT, GMT, bilirubin, AB0. 4ECG (older 45). 4Xray of chest (older 60 let). 4function exam –cardiological, lung, nephro, hemato Why to do PreOP exam? ldecrease RISKs lwhat is the benefit of surgery lAirway exam lGA // regional? lpremedication History of Airway Management lHistory -any difficulty, teeth? -TS scar [narrower trachea]? !!! Tell the truth about troubles in anesthesia !!! lExamination: -Mouth Opening(3 fingers) -free teeth -gotic palatum -big tongue, small mouth -hypoplastic mandibula -anteposition of larynx = mandibula-os hyoideum <3 fing. -fletion, extension of head -Mallanpati Difficul airway • * Obesity - body weight > 110kg • * Mouth opening - inter-incisor distance < 4cm in an adult • * Ability to prognath - a large overbite, or the inability to shift the lower incisors in front of the upper incisors • * Thyromental distance - The distance from the thyroid cartilage to the mentum (tip of the chin) should be > 6.5-7 cm. • * Mentum-Hyoid distance - Similar to thyromental distance, and should be at least 3-4 finger-breadths. •Mouth opening Should be adequate (3 cm or more) to easily •allow a laryngoscope plus endotracheal tube (ETT). •Patients with temporomandibular joint (TMJ) disease or trismus may not be able to open widely, and may require fiberoptic intubation by the nasal route Teeth Edentulous patients are always easier to intubate, but are often more difficult to ventilate with a face mask. Patients with teeth in poor condition or with very prominent teeth may be more difficult to intubate. Thyromental distance Distance from the mentum of the mandible to the thyroid, with neck fully extended. If distance is less than 6 cm there is less space for the tongue to be displaced with laryngoscopy Mallanpati OTI easy 95% OTI difficult 50% Your easy patient? Predicted difficult airway lepiglotitis labscesus (submandibular, retropharyngeal) ltetanus ltrauma of the neck, mouth ltumor of the larynx, faryngx ltemporomandibular joint disease lobezity Respiratory risk lspirometry, Blood gases lCOPD lAstma lchronic bronchitis lacute inflamation of lunx Cardiovaskular risks lECG (load) lECHO, (coronarography) lhypertension ( cardiac work, failure) lischemia (AP, IM, rhythm) lCor pulmonale lValvular abnormalities (Ao stenosis) Prophylaxis: lBeta blockers, ? antihypertenzive drugs … other risks lDiabetes mellitus lHepatic –porphyry –failure lRenal lCNS -epilepsy -mm. (Myastenia gr., ) Conversation before GA or RA 4empty stomach - last food, fluid 4tooth (artificial, free) 4weight 4allergy 4complication of CA in his/family history 4check-up questionnaire 4agreement with anaesthesia PreOP starving l24 h no smoking l6-8 h no eating 4h breast milk l2 h last clear liquid Premedication usually p.os - evening + morning 4sedation/anxiolysis (Benzodiazepines) 4analgesia only if pain (opioids) 4reduce airway secretions + heart rate control + hemodynamic stability 4prevent bronchospasm 4prevent and/or minimize the impact of aspiration 4decrease post-op nausea/vomiting Premedication goal: cooperating patient anxiolysis leaser induction of A. llower consumption of drugs Risk of Aspiration •Severe obesity •Symptoms of gastroesophageal reflux •Advanced pregnancy •Severe ascites •Opioid administration or other condition resulting in delayed gastric emptying •History of gastroparesis or other motility disorder •Bowel ileus or bowel obstruction ((Metoclopramid, sodium citrate with citric acid)) → RSI Rapid Sequence of Induction Induction of Anesthesia 1 – 3 drugs i.v. = llethal dose lthe most effective way => no self-controle, unable call for help, suppress of vital autoregulating mechanisms lunmask compensated disturbances (hypovolemia, relative respiratory insuf, ...) Induction l30 - 60s from fully conscious to vitally dependent on anaesthetist lMoment with big influence on the rest of the life. P.S. Did you ever sign “Informed Consend“ Airways Indication for intubation: 4need of relaxation or artificial ventilation 4full stomach (Rapid Sequence of Induction) 4Laryngeal mask 4Face mask 4Orotracheal intubation, nasotracheal intubation with direct laryngoscopy 4Tracheotomy 4Cricothyreotomy INTUBATION - Always consider why you are exposing the patient to the risk, albeit small, of intubation- a.) protection from gastric aspiration and secretions b.)access and maintenance-in difficult airway and difficult surgical positions/procedures c.) provide positive pressure ventilation- can be done for shorter periods with a mask or LMA d.) oxygenation- to provide a controlled concentration of oxygen up to 100%, also provides for complete scavenging e.) secretions- facilitates removal of secretions via suctioning In the End of Anesthesia 4Stable ABCD: extubation, pain, temperature control, PostAnest.CareUnit 4Unstable: analgosedation + arteficial ventilation - transport to ICU Extubation lpay now or pay later - if in doubt, leave it in. lalways awake if - difficult mask airway or intubation, full stomach, surgical considerations, sux contraindicated lawake means awake - if in doubt, leave it in Postoperative care 4ICU or standard department 4monitoring according to the type of OP + health 4control laboratory 4treatment of acute pain 4infusion therapy, blood loss OR checklist lTest A.Machine = does it inflate O2 [before anesthesia] lIdentity lProcedure, side lAllergy lDocumentation (fill in, Informed Consend) li.v. access lMonitoring Optimal anesthesia – cardiovascular stability lf 50..90/min lSTK max 115% of starting lDTK > 60 mmHg lPAOP < 12 mmHg lcorrect anemia ORoom •„Dobry den“ • fellowship anestetist ~ A.nurse confidence, respect •hygiene – wash your hands before every case, use gloves Figure 1. Operating room layout showing how space can be controlled by positioning the anesthesia personnel (A), machine (M), and drug cart (D). The infusion (I) is in view and a visitor (V) can be provided with a good view while remaining outside the "controlled space." Mortality of anaesthesia (ASA I) 40,008-0,009% primary connected with A 40,01-0,02% partially connected with A 40,6% 6 day mortality after operation 43 times danger than flying [1: 775 000] Complications of GA !!! No risk = no anaesthesia !!! 4difficult intubation, ventilation … asfyxia 4aspiration of stomach fluid … pneumonia 4overdose anaesthetic … cardiovascular, respiratory colaps 4misfunction of monitor, machines 4organ failure (AIM, dekompensation COPD, hepatitis, ...) 4malignant hyperthermia 4anaphylactic reaction / shock Postoperative Nausea and Vomiting Risk of anesthesia - mortality lTrend to improve safety => low tolerance to complications of anesthesia Mortality and Anesthesia: l 1952 1 : 2 000 (Beecher, 1954) l 1982 1 : 10 000 (NCEPOD 1987) l 2001 1 : 50 000 – 220 000 (Brown, 2002) lRisk of death in aviation 1: 755 000 (1997) +Death and Anesthesia lhypoxemia / UPV / intubation of oesophagus laspiration / regurgitation of gastric fluid to lung lcirculatory instability (ischaemia) lover dose lanaphylaxis, interaction of drugs !!! Death was preventable (30-60%) !!! Importantly, 64 percent of the deaths were inevitable, a finding suggesting that only one-third were preventable. http://web.squ.edu.om/med-Lib/MED_CD/E_CDs/anesthesia/site/content/v03/030008r00.HTM Phraseology lanalgesia = elimination of pain lsedation = elimination of stress, impatience, fear –Minimal Sedation (Anxiolysis) is a drug-induced state during which patients respond normally to verbal commands. Although cognitive function and physical coordination may be impaired, airway reflexes, and ventilatory and cardiovascular functions are unaffected. –Moderate Sedation/Analgesia (“Conscious Sedation”) is a drug-induced depression of consciousness during which patients respond purposefully to verbal commands, either alone or accompanied by light tactile stimulation. Phraseology –Deep Sedation/Analgesia is a drug-induced depression of consciousness during which patients cannot be easily aroused but respond following repeated or painful stimulation. The ability to independently maintain ventilatory function may be impaired. Patients may require assistance in maintaining a patent airway, and spontaneous ventilation may be inadequate. –General Anesthesia is … loss of consciousness during which patients are not arousable, even by painful stimulation. •inability to maintain ventilatory function = often require assistance in maintaining a patent airway, and positive pressure ventilation may be required. Continuum of depth of sedation ASA 2004/2009 Anesthesia lGeneral –inhal., –TIVA lRegional –central block (SA, EPI) –periferal blocks (brachial, nervous) –local anesthesia (eye – cornea + conjunctiva, infiltration) Combined = GA + EPI-line Useful web http://www.virtual-anaesthesia-textbook.com/ www.asahq.org www.akutne.cz www.cobatrice.org http://airwaymicrotext.homestead.com Virtual Anesthesia Machine: lhttp://www.anest.ufl.edu/vam/ lwww.simanest.org Preoperative evaluation and premedication lRisk of A lPreOp evaluation lPremedication lSafety in OR Next week: lAnesthesia Machine lMonitoring