Introduction to Anesthesia- Student .pptx

INTRODUCTION TO ANESTHESIA  Differe Differentiate between general, MAC, and ntiate sedation techniques. Describ Describe and explain the phases, stages e and and planes of a general anesthetic. explain...

INTRODUCTION TO ANESTHESIA  Differe Differentiate between general, MAC, and ntiate sedation techniques. Describ Describe and explain the phases, stages e and and planes of a general anesthetic. explain Examin Examine various methods used to STUDENT e perform anesthesia inductions. LEARNING OUTCOMES Describ e Describe the types of extubation techniques. Describ Describe the continuum of sedation depth e as it relates to anesthesia practice. Verbali Verbalize considerations that influence ze anesthetic choice.  BREADTH OF THE SPECIALTY Obstetric Pediatric Cardiothoraci Neuroanesthe anesthesia anesthesia c anesthesia sia Anesthesia for Pain Critical Care Outpatient Management Medicine surgery  General Anesthesia Monitored TYPES OF Anesthesia Care ANESTHESIA Regional Anesthesia WHAT WORDS COME TO MIND WHEN YOU HEAR “ANESTHESIA”? How does anesthesia work? Watchful Care By Marianne Bankert NURSE ANESTHESIA HISTORY  CONSIDERATIONS THAT INFLUENCE THE CHOICE OF ANESTHETIC TECHNIQUE Patient Safety Elective vs emergency Airway Patient comfort Duration of surgery Preference Patient age Coexisting disease Recovery time Surgical site Post anesthesia care Positioning unit discharge criteria  Optimal patient safety Patient satisfaction Excellent operating conditions for surgeon IDEAL Allow rapid recovery ANESTHETIC TECHNIQUE Avoid postoperative side effects Low cost Early transfer or discharge from PACU (cost)  GENERAL ANESTHESIA Broad Definition Drug-induced depression of the CNS resulting in the loss of response to and perception of all external stimuli ASA continuum of sedation “is a drug-induced loss of consciousness during which patients are not arousable, even by painful stimulation.”  GENERAL ANESTHETIC TYPE Inhalation Only Intravenous Only Combination inhalation/IV TIVA i.e. Balanced Anesthesia  Unconsciousn ess Attenuation of autonomic responses to Amnesia noxious stimulation Componen ts of Anesthetic State Immobility Analgesia  Phases of General Anesthesia Induction Maintenan ce  Administering anesthetic drugs (Inhaled or IV) to induce a state of INDUCTION anesthesia (DEFINITION) Inducing a state of unconsciousness Typically>>>> Induction of General Anesthesia  PRE-INDUCTION MONITORS Routine Monitors: EKG, NIBP, Pulse-Ox, CO2, Temp Standard monitors should be used as minimum standards for all anesthetic techniques AANA Standard IX / ASA Standard II Special Monitors (Examples) Consider additional monitoring such as arterial lines when consistent and continuous monitoring of BP needed Consider CVP Risk for bleeding, or need to monitor CVP to guide intraop fluid management What other Monitors may be necessary for procedure:  What is the percent O2 in Room Air? Oxygen application prior to initiation of induction sequence Purpose: to replace nitrogen in patients' functional residual PRE-INDUCTION capacity (de-nitrogenation) P R E OX Y G E N AT I O N Why preoxygenate?_____________ Have patient breath 100% oxygen via face mask for a period of 3-5 minutes OR instruct patient to take 8 vital capacity breaths  I N T RAV E N O U S I N D U C T I O N O F ANESTHESIA A single ideal intravenous anesthesia induction drug has yet to be developed Desirable properties for induction agents: Rapid and smooth onset and recovery Analgesia Minimal cardiac and respiratory depression Antiemetic actions Lack of toxicity or histamine release Advantages pharmacokinetics and pharmaceutics  IV induction: produces a rapid onset of unconsciousness Commonly used anesthetic drugs: Propofol (most commonly used) sedative hypnotic (GABA) Thiopental (barbiturate) INTRAVENOUS Brevital (barbiturate) Etomidate sedative hypnotic INDUCTION (GABA) OF Ketamine (IV/IM) NMDA receptor antagonist- dissociative ANESTHESIA Opioids Benzodiazepines Generally used for adult patients or patients with preexisting IVs Choice of agent used dependent upon patient comorbidities and situational needs  Room Setup, Perform Machine Check Confirm checklist “sam tide” suction, airway, machine, tape, IV, drugs, equipment Apply Monitors Position patient Baseline Vitals STANDARD To provide reference, possible stop point INDUCTI ON prior to proceeding SE QUE NCE Preoxygenation Administration of Induction agents (iv/inhalation/combination) Eyelid reflex Mask Ventilation Neuromuscular blocking agent IF you are planning to use an LMA or perform a MASK case- no paralytics given Airway instrumentation  “Intravenous injection of an anesthetic to produce unconsciousness followed immediately by a neuromuscular blocking drug that produces a rapid onset of skeletal muscle paralysis” Room Setup, Perform Machine Check Confirm checklist “sam tide” suction, airway, machine, tape, IV, drugs, equipment Apply Monitors Position patient RAP I D SE Q U E N CE Baseline Vitals INDUCTION OF ANESTHESIA To provide reference, possible stop point prior to proceeding Preoxygenation Administration of Induction agents (iv/inhalation/combination) Cricoid pressure applied prior to loss of consciousness Eyelid reflex Neuromuscular blocking agent Airway instrumentation- Always ETT What situation would necessitate a RSI?  Most common method for inducing children in North America, scheduled for elective case Why? Also known as mask induction I N H A L AT I O N Oxygen + Volatile Anesthetic INDUCTION OR Oxygen + Nitrous Oxide + Volatile Anesthetic Volatile Anesthetic: Desflurane vs Sevoflurane Sevoflurane non-pungent & not an irritant  Steps Prime circuit Monitors (primarily pulse oximeter) Mask Application- administration of O2/Sevo OR O2/N2O/Sevo Loss of Consciousness INHAL ATION Maintain Ventilation (Mask) INDUCTION remain vigilant by monitoring for adequate exchange (Spontaneous or Controlled) PIV placement +/- IV induction +/- Paralytics Airway Instrumentation Inhalation (LMA/ETT)induction Verify placement  Assess LOC and LOSS of Lid Reflex Tape Eyes Closed Provide Positive Pressure Ventilation Via Face Mask (+/- oral airway) Assess ease/difficulty of ventilation Maintain Oxygenation = LIFE In what ways can we assess the POST- quality of our ventilation? +/- Administration of Paralytics STANDARD Airway Instrumentation INDUCTION Laryngeal Mask Airway (no paralytics) Endotracheal Tube Endobronchial Tube (One lung ventilation) Are there exceptions to performing ventilation after induction?  Defined as “the management of physiological functions and the maintenance of surgical anesthesia following induction and until emergence” Maintain surgical anesthesia MA I N T E N A N C Goals: Maintain physiologic homeostasis E Monitoring is needed to ensure that these goals are met Requires Vigilance  Provide: Unconsciousness, amnesia, analgesia, immobility, muscle relaxation, and control of the sympathetic nervous system response to noxious stimuli Accomplished by a combination of drugs Inhaled and IV- with or MAINTENANCE without neuromuscular OF SURGICAL blocking agents ANESTHESIA (procedure dependent) Drugs administered on basis of specific goal relevant to pharmacologic effect Prevention of intraoperative awareness  Maintain euvolemia for normotensive patients Fluid Management: Traditional vs Goal Directed Replace fluid: NPO, Bowel Prep? Monitor/Chart/ Estimate and Replace blood loss Monitor urine output Titrate, administer and re-dose MAINTENANCE OF medications as necessary P HYSI OLOG I C H O M E O S TA S I S Maintain positioning and monitor pressure points Nerve injury prevention Maintain and Monitor Adequacy of Ventilation Prevent Hypothermia  MAINTENANCE MONITORING Stay Vigilant Monitoring Oxygenation Vitals signs Anesthetic Depth Level of muscle relaxation Positioning  STAGES OF GENERAL ANESTHESIA I: Analgesi a II: Delirium III: Surgical Anesthe sia IV: Overdos e  STAGE I: ANALGESIA Begins with Ends with Patients administratio loss of response to n of induction consciousnes pain is agents s altered  STAGE II: DELIRIUM Begins with loss of consciousness Period of excitation and involuntary movement Signs: Irregular respirations periods of apnea, breath holding Dilated pupils and Divergent gaze Tachycardia Hypertension Delirium  Begins with onset of regular breathing pattern Ends with loss of spontaneous respirations STAGE III: Deep sleep not subject to SURGICAL rousing ANESTHESIA Consists of four planes Most surgical procedures can be safely performed in Stage III: Planes 1 and 2  Loss of lid reflex Respirations regular and deeper than normal Pupils react to light Swallowing, retching, and vomiting reflexes disappear and SURGICAL ANESTHESIA: reappear in that order S TA G E I I I - P L A N E 1 Respiratory response to skin incision decreased Decrease muscle tone  Starts when eyeballs become concentrically fixed Regular respirations with decreased tidal volume Respiratory response to skin SURGICAL incision disappears ANESTHESIA: Moderate loss of muscle tone S TA G E I I I - P L A N E 2 Reflex closure of vocal cords begins to disappear Pupils unreliable  Begins with decrease in intercostal muscle activity Ends when intercostal activity absent and respirations is completely diaphragmatic SURGICAL Diaphragmatic breathing>jerking ANESTHESIA: S TA G E I I I - P L A N E 3 movement Pupils continue to dilate  Begins with complete loss of intercostal activity Ends with loss of spontaneous respiration SURGICAL Pupils completely dilated ANESTHESIA: S TA G E I I I - P L A N E 4 Nonresponsive to light All muscle tone lost  Aka Respiratory paralysis Aka “Too Deep” Cessation of respiration due to concentration of anesthetic S TA G E I V: agent OV E R D O S A G E Ends with Circulatory Collapse Anesthesia should be lightened Immediately  “is a transition process where a patient goes from general anesthesia to awake and spontaneously breathing.” EMERGENC Critical period of recovery from E general anesthesia with the return Consciousness Neuromuscula Airwayof: protective r conduction reflexes A plan of emergence should be developed based on patient’s comorbidities and surgeons needs  Estimate remaining duration of surgical procedure Decrease anesthetic depth (If planning for AWAKE Extubation) Assess Level of Paralysis TOF/ Acceleromyography Administer Reversal When appropriate for procedure (deep fascia EMERGENCE closed) P R E PA RAT I O N When TOF of at least 2, preferably 3-4 twitches Adequate recovery from neuromuscular blocking agents should be established prior to extubation, TOF ratio >90% Awareness possible  Administer medication to prevent PONV Pain management Opioids Requirements based upon patient weight, procedure, physiological status, and opioid tolerance Respiratory rate can be a useful indicator of adequate analgesia EMERGENCE P R E PA RAT I O N Diffusion Hypoxia Occurs when N20 has been used Diffuses rapidly from blood into alveoli replaced with RA if not on 100% O2 Administer 100% oxygen for 5-10 minutes Suction Oral/Pharyngeal Cavity Place Oral Pharyngeal Airway or Nasal Pharyngeal Airway  Evaluation of signs and stages of anesthesia during emergence Stage III Deep extubation Stage II: Excitement (do not extubate during this phase) Emergence: Irregular breathing/breath holding Possible agitation Laryngospasm and regurgitation Stage I Extubation performed once stage I is reached (awake extubation)  IF HIGH RISK FOR A S P I R AT I O N O R D I F F I C U LT I N T U B AT I O N - E X T U B AT E O N LY W H E N PAT I E N T F U L LY AW A K E. PAT I E N T C O N S C I O U S AND RESPONDING TO SIMPLE COMMANDS, “ O P E N YO U R E Y E S ” “ SQUEEZE MY HAND” E N S U R E A D E Q U AT E REVERSAL OF NMB H E M O DY N A M I C A L LY S TA B L E & NORMOTHERMIC A D E Q U AT E S P O N TA N E O U S V E N T I L AT I O N W I T H : R E G U L A R R AT E T I D A L V O LU M E S > 6 - AWAKE Extubation Criteria 8ML/KG R AT E > 8  D E EP DEEP EXTUBATION VS AWA K E Indication Contraindication E XT U B AT I O N Avoid bucking, Full Stomach – coughing, severe GERD, Awake straining Trachea is extubated response to ETT only when the patient responds to simple Avoid Difficult commands and is Cardiovascular intubation breathing response to ETT spontaneously Deep Avoid Risk or Chosen when the bronchospasm regurgitation presence of an ETT is in a patient at and/or aspiration to be avoided during emergence to prevent low risk for of gastric “bucking” and aspiration of contents is a straining gastric contents concern What type of Surgery would Warrant a deep Extubation?  PAT I E N T A N E S T H E T I C D E P T H - S TA G E I I I E N S U R E A D E Q U AT E REVERSAL OF NMB H E M O DY N A M I C A L LY S TA B L E & NORMOTHERMIC A D E Q U AT E S P O N TA N E O U S V E N T I L AT I O N W I T H : R E G U L A R R AT E , T I D A L V O LU M E S > 6 - 8 M L / K G , R AT E > 8 TECHNIQUE- M A I N TA I N A N E S T H E T I C DEPTH S U C T I O N A I R WAY P L A C E O PA ( A S S E S S F O R B R E AT H HOLDING) E X T U B AT E P L A C E FA C E M A S K T O DEEP Extubation Criteria ASSESS FOR CONTINUED A D E Q U AT E V E N T I L AT I O N  EXTUBATION Deep extubation Awake extubation  MONITORED ANESTHESIA CARE Monitored Anesthesia Care does not describe the continuum of depth of sedation, rather it describes “a specific anesthesia service in which an anesthesiologist has been requested to participate in the care of a patient undergoing a diagnostic or therapeutic procedure.” If the patient loses consciousness and the ability to respond purposefully, the anesthesia care is a general anesthetic, irrespective of whether airway instrumentation is required.  MONITORED ANESTHESIA CARE The provider of monitored anesthesia care must be prepared and qualified to convert to general anesthesia when necessary May require varying levels of sedation, analgesia and anxiolysis Desired end points to provide patient comfort, maintain cardiorespiratory stability, improve operating conditions and prevent recall of unpleasant perioperative events Ideally patient should be able to communicate during procedure Therapy should be administered to treat pain, anxiety and agitation Combination Local/Mac  During monitored anesthesia care the anesthesia provider performs number of services: Diagnosis and treatment of clinical problems that occur during the procedure Support of vital functions MONITORED Administration of sedatives, ANESTHESIA analgesics, hypnotics, anesthetic CARE agents, or other medications as necessary for patient safety Psychological support and physical comfort Provision of other medical services as needed to complete the procedure safely  MONITORED ANESTHESIA CARE Local Anesthetic Which drug Characteristics Recommended Dose Max Dose Concentration (know how to figure this out!!!) With/without preservatives  Who is not a good candidate? Children Confused MONITOR ED ANESTHE SI A Uncooperative CAR E Unable to follow commands Patients with tremors/ RLS Patients unable to lie down flat  “An analysis of the ASA Closed Claims Project database focusing on MAC likewise revealed that oversedation and respiratory collapse most frequently lead to claims” MONITORED ANESTHESI A CARE Be vigilant, have airway equipment present, DO not perform MAC without proper equipment… be prepared to convert to general in needed ASA PUBLICATION ON SEDATION CONTINUUM OF DEPTH OF SEDATION: DEFINITION OF GENERAL ANESTHESIA AND LEVELS OF SEDATION/ANALGESIA  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, DEFINITION airway reflexes, and ventilatory and cardiovascular functions are unaffected ASA publication  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. No interventions are required to maintain a patent DEFINITION airway, and spontaneous ventilation is adequate. Cardiovascular function is usually maintained. Reflex withdrawal from a painful stimulus is NOT considered a purposeful response. ASA publication  Deep Sedation/Analgesia is a drug-induced depression of consciousness during which patients cannot be easily aroused but respond purposefully following repeated or painful stimulation. The ability to independently maintain ventilatory function may be DEFINITION impaired. Patients may require assistance in maintaining a patent airway, and spontaneous ventilation may be inadequate. Cardiovascular function is usually maintained. ASA publication