Anes I Recap LCouch W25 PDF

ANES I RECAP VETC2012 review for VETC2015 Laura Couch RVT, MSc, One Health (GradCert), BSc, RVT, AMEE ESME (cert), RECOVER RECAP: FLOW/FUNCTION & ADS LEAK TEST FUNDAMENTAL ADS PARTS …BOTH TYPES OF BREATHING SYSTEMS USE THESE PARTS 1. Gas supply with gauge & pressure reducer (+/-...

ANES I RECAP VETC2012 review for VETC2015 Laura Couch RVT, MSc, One Health (GradCert), BSc, RVT, AMEE ESME (cert), RECOVER RECAP: FLOW/FUNCTION & ADS LEAK TEST FUNDAMENTAL ADS PARTS …BOTH TYPES OF BREATHING SYSTEMS USE THESE PARTS 1. Gas supply with gauge & pressure reducer (+/- line pressure gauge) 2. Flow Meter 3. Flush Valve *bypasses #2. Flow Meter & #.4 Vaporizer :. 50psi & 35-75mL/min 4. Anesthetic Precision Vaporizer 5. Common Fresh Gas Outlet 6. (Pause here and ask what breathing system to be used to continue to connect appropriate scavenge…) 7. Scavenge interface to wall Evacuation System)  HIGH 2200 PSI > INTERMEDIATE 50 PSI > LOW 15 PSI 1. Compressed O2/Carrier gas - High pressure 2200 psi & pressure gauge 2. Regulators – Reduces to Intermediate pressure 50 psi (wall) (+/- line pressure gauge) 3. Flow Meter – Sets flow rate of carrier gas & further reduces gas to low pressure 15 psi (safe for vaporizer & patient) 4. O2 Flush - Fresh O2 source Intermediate pressure 50 psi. BYPASSES FLOWMETER & VAPORIZER :. NO anesthetic agent. Uses: machine leak test, flush system clear of anesthetic gas, emergencies. NON- REBREATHING SYSTEM 5 NON-REBREATHING (NRB) OXYGEN FLOW RATES  Require high flow rates per unit body weight during all periods: 300 mL/kg/min*must memorize  Always used on patients 7kg? Use adult RB circuit COAXIAL Rebreathing systems always more advantageous in K9/Fe  BAG SIZE CALCULATION (NONREBREATHING & REBREATHING)  Reservoir Bag Functions:  Inspiratory reserve for patient  Administering positive pressure ventilation  Allows anesthetist to monitor ventilation  Calculation of bag size for small animals:  = [ (patient tidal volume 15 mL/kg) x 6 ] *memorize  [10 kg animal x (15 mL/kg)] x 6 = 900 mL  Convert to L (divide by 1000) = 0.9L  Round UP = 1 L bag ADS LEAK TEST PROTOCOL How to perform it? What if there is a leak?  What do you do?  Order of check points? When & why measure leak rate? What part of the ADS does it not test?  Why?  How can we know these parts are ok? 1. Connections 2. Breathing Bag 3. Breathing circuits hoses, connections 4. FRESH GAS O-Ring, adaptor or MOST hose 5. Rebreathing: Soda Lime COMMON canister cracked, or o- rings not LEAKS sealing 7. Unidirectional Valve Domes LOCATION 8. Leak test done with a S capnograph adaptor on Breathing Circuit Pressure Alarm Find the leak! Do not accept a leak it unless all efforts are exhausted **Occupational health and safety hazard** - Spray soapy solution to locate leak to ensure you did not miss something you can fix - MAX acceptable leak rate 200mL/min (0.2 L/min) COMMON ERRORS WITH ADS  1. INCORRECT EVACUATION  Most dangerous = scavenge from RB to NRB = closes system  Any set up that contributes to WAG  To connect circuit directly to wall without use of interface  Too strong a suction will create negative pressure  Sidestream capnograph not scavenged  Quick connect at wall not secure  Must hear a click, button should not be jammed  And ensure it is snug by gently pulling 2. AN INCORRECT ETT LENGTH CHOICE EXCESSIVE DEAD SPACE = REBREATHING CO2, ADDS RESISTANCE, INADEQUARE DELIVERY TOO SHORT (ADAPTOR IN MOUTH) = DISCONNECTS EASILY, POOR ACCESS, INJURY TO GUM PLACED PASTED THORACIC INLET/TOO FAR = OCCLUSION AT CURVE OF TRACHEA/BLOCKAGE, BRONCHI INTUBATION (CAN CAUSE INADEQUATE DELIVERY) OR AN INAPPROPRIATE BREATHING SYSTEM CHOICE COMPLICATIONS OF INTUBATION COMPLICATION DURING INDUCTION  Esophageal intubation  Airway not secure – could aspirate regurg, or air can occlude > hypoxia  Laryngospasm cats, sheep  Apnea  hypercapnia & hypoxia  Hypoxia  hypoventilating on room air  Vagus nerve stimulation (drop in HR)  Brachycephalic dogs or other breed deformities  Difficult intubation, prolonged  Overzealous & harmful intubation efforts  Overinflation of cuff – tare or pressure necrosis  Obstructed endotracheal tube  Waiting too long to remove the tube  Improper cleaning and sanitizing between uses  Tracheal and/or laryngeal irritation leading to postsurgical cough 17  ETT CUFF INFLATION RECAP SEE PROCEDURE FROM ANES I  2 People required to perform a safe minimal occlusive volume (MOV) inflation  Quick Overview  Close APL Valve & watch gauge – inducer role  Ensure O2 Flow is on at high end of induction rate  Be ready @ patient end with syringe connected to pilot balloon value – monitor role  Squeeze bag to 20 cmH2O dogs, 15 cmH2O cats (inducer) AND Listen for leak (monitor)  ONLY inflate the cuff during the leak sound and UNTIL the leak stops  May take a few times – max 3 ideally  No Leak? Then don’t add AIR!  Instructor will confirm with a cuff inflation device  Turn on ISO only after there is a confirmed seal  Watch depth of patient during! At risk of movement! 18  CUFF TIPS & COMPLICATION PREVENTION!  Do not inflate cuff without first checking to see if there is a leak around it – some bulky cuffs create their own seal  Caution when moving or rotating animal with inflated ETT cuff  DISCONNECT from circuit before moving (& occlude circuit to avoid additional WAG & turn off O2)  Stabilize head/maxilla during jaw tone checks  Ensure the tongue is not entrapped in tube tie or between teeth (swelling will occur)  Tracheal tears are not uncommon in cats due to moving animals with cuff inflated and breathing tubes Complications are real, be aware to prevent :  Laryngeal damage from overzealous or forceful intubation – inflammation, edema, hemorrhage  Laryngospasm (cats, sheep) 19  ….COMMON ETT Tracheal damage COMPLICATIONS  Tears - Over-inflated cuff, moving or twisting patient with inflated cuff  May lead to mucosal damage, tracheal rupture (SQ emphysema, pneumomediastinum, etc.)  ETT obstruction  Secretions (mucus most common), cuff over inflation  Endobronchial intubation  ETT introduced too far into the airways  Must measure tube at time of intubation, ETT should not extend past the thoracic inlet  Leads to hypoxemia +/-hypercapnia  ETT inhalation or ingestion  Tube chewed (usually upon recovery)  Do not wait too long to extubate! Be ready with con’t depth assessment and knowing signs of extubation  Risk of bronchospasm in some species –e.g. pigs and cats 20  3. UNTRACKED SODA CARBON LIME USE  Use is Based  not colour! on time & granule consistency  Very caustic: wear gloves & mask DIOXIDE ABSORBER  Ensure ADS leak test is done correctly or granules could enter breathing system CANISTER  Leak test AFTER refilling  Discard used in designated (dedicated) bin Small Animal 8-12 hours of use ok Lab Rules: 8 hours max, then replace with new Ensure you are recording anesthesia time on canister during or post anes 21  CLINICAL SIGNS OF CO2 ABSORBENT EXHAUSTION = BAD Capnograph Monitor Signs of Soda Lime Exhaustion: InCO2 is >2 mmHg Capnogram does not return to baseline ETCO2 high/hypercapnia Consider NBR dilution so capnometer not always precise Patient Signs of Hypercapnia d/t exhaustions = Very BAD: Increased RR (attempting to compensate for increased inspired CO2) 22  4. OHS Hazards – OUR SAFETY a) WAG, INHALANTS - Max exposure to volatile anesthetic agents should be less than < 2 parts per million (ppm) – But, it must be greater than >125 ppm to identify isoflurane by SMELL :. TOO MUCH EXPOSURE, risking OHS, exposure may be occurring even if there is no perceived odour  Do no accept any ADS leaks, turn off oxygen flow if disconnecting (keep hand on flow meter please until it is turned back on as to not forget), do not disconnect circuit or deflate ETT cuff prior to extubation signs & extubation, active scavenge wall connection loose Recall ISOFLURANE – Toxic to reproduction, eye/skin irritant, fatigue/dizziness/nauseant b) INPROPER HANDLING of COMPRESSED GASES – OXYGEN IS AN IGNITOR & FUELs FIRES (Oxidizing gas) & High compressed pressure = missile > 23 HALOGENATED ORGANIC COMPOUNDS =INHALANTS: WHY WE USE THEM & THEIR ADVANTAGES  Produce state of general anesthesia with hypnosis, unconsciousness, amnesia (in humans), muscle relaxation, and immobility  Both sevoflurane & isoflurane liquid at room temp, vaporized with carrier gas (100% oxygen most common) where it travels to lungs at alveoli, then diffuses into bloodstream  Rate of this diffusion controlled by the concentration gradient between alveolar & blood stream, & the lipid solubility of the agent.  Takes sometime for the concentration needed to plateau and cause the effects we need, and the reason why we need a high flow oxygen rate to help carry the drug quickly unless that concentration is reached  Reversible CNS depression  Eliminated by the lungs  MAC – Minimum Alveolar Concentration MAC Definition: the expired (end-tidal alveolar) concentration of an inhalant anesthetic agent that prevents purposeful movement in response to a noxious stimulus in 50% of observed subjects  NONE of these patients in this study had ANY other drugs on board, :. not balanced anesthesia :. We often can adjust below MAC  ALWAYS adjust based on depth assessment and panoramic view of vitals not vaporizer % setting  MAC & MAC FACTORS (FX) Factors and setting choices to use:  MAC = *Dogs Isoflurane 1.3%, Cats 1.3-1.6%  1.5fx x MAC = Surgical anesthesia  *Dogs Isoflurane 1.5fx x 1.3% = 1.95% (2%)  Aka Induction Rate  Once at plane II, reduce iso to what is appropriate for your patient/procedure  2fx x MAC = deep anesthesia *Dogs Isoflurane 2 x 1.3 = 2.6%  THEREFORE DON’T ALLOW YOUR PATIENT TO GET TOO DEEP AT INDUCTION  REMEMBER TO DO FREQ DEPTH CHECKS AND TURN DOWN usually 5-15 minutes only  MAC varies with species, age, body temperature, metabolic status...  Use 1.5 x MAC (2%) for INDUCTION if patient is in stage III plane I  If patient at stage II use injectable for fast action to deepen  If patient is plane III maybe hesitate to turn on iso or turn on at MAC or lower!  The more hypothermic, the deeper your patient can/will be!  Hypothermia reduces MAC requirements!  BE SAFE Safety of Animals & Staff WITH DRUG  Supervise all drugs  Do not leave controlled drugs unattended or & SYRINGE without a lab IDENTIFCATI  Drawing up drugs: CHECK OFTEN (x2-3 times) ON what drug, concentration, dosage, dose, & route you have before injecting then CHECK AGAIN.  EVERYTHING MUST BE LABELLED  Or we will ask you to discard and redraw it up  Try and use coloured preprinted syringe labels found in the binder  Confirm again with instructor before ANY administrations  Prepare syringes and labels during evening set-up  Discard & get new if accidently contaminated, DO NOT think it is no big deal and continue to use it  LOG Controlled Drugs, log splits or wasting of unused controllled drugs. Ensure accuracy and witnessed.  ATIPAMAZOLE REVERSAL  Reverses Alpha-2 Agonists AGENTS  Dexmedetomidine NO RESERVALS FOR ANYTHING  NALOXONE ELSE WE ARE USING!  Reverses Mu Agonist Opioids  Hydromorphone  Partially reverses Butorphanol  FLUMAZENIL  Reverses Benzodiazepines  Diazepam or Midazolam  MONITOR CHECKS BE SURE TO TEST ALL EQUIPMENT Capnograpn (ensure it is scavenged), Pulse OX, DURING SETUP Oscillometric, Doppler, ECG, Temp probe & thermometers, Stethoscope and Esophageal Stethoscope, Patient Warming Device, IVF Pump ***Plug in all equipment!!  Prepare – review pre-op notes & prepare anes Plan  Admit & PE: note behaviour, CV & Resp functions, pre-op blood work, confirm consent, weight (kg) & fasting & all procedures and requests… OVERVIEW  Premed – IM  Patient warming begins – turn on and apply blanket  IVC Placement OF  Assess Patient> Premed Effect with Pre-Oxygenation (surgical shave will likely occur just before this unless cat neuter) ANESTHESIA  Induction > Intubation > Confirm Placement > change patient from sternal to lateral recumbency > connect to O2  ETT cuff Inflation procedure  Depth Assess LAB  Monitors placed  1. Pulse Ox FLOW  2. Capno  3. Oscillometric & doppler  4. ECG (red dots on pads and snap electrode to be used)  5. Espohageal & Temp Probes  6. Warming Device Check (should already be on from prep) & (7.) IVF (on ASAP) 8. Record  Maintenance & Monitoring @ Plane II  Procedure  Extubation & Recovery, Monitoring & Support  Transfer patient to Sx Group  Post op checks , then round to Clinic RVT & DVM  Discharge  …RECOVERY & EXTUBATION STEPS  Maintain patent airway, monitor depth & vitals continuously 1. Check for regurg, position appropriately incase silent regurg occurs CAT DOG 2. Do not detach breathing circuit, keep on 100% Oxygen until extubated! (reduces WAG & helps prevent hypoxemia when patient is still Weak lateral 1-2 Swallow hypoventilating) palpebral 3. Be ready to extubate when medial palpebrals become strong ***When to remove ETTube? – see chart for signs & extubate promptly at any of them  Movement, body Movement 4. Team member continues gentle restraint – be ready for anything tension 5. DEFLATE CUFF promptly at 1st sign of extubation Swallow (possibly 6. Promptly untie tube after deflation, pull ties forward to avoid getting stuck behind canine teeth or in fur too late, increased 7. Extend head, & remove the tube in one slow, steady motion & hold the risk of tube firmly – do not hold any connectors incase they come apart laryngospasm) 8. Keep restraining & avoid animal biting tube with proper technique (pry jaw open Ear Flick (possibly with safe technique) inconsistent & 9. Once ETT remove promptly check for adequate airflow through mouth or nares – essential, & turn off flow meter! unreliable but extubate if you get 10. Place pulse oximeter, provide flowby O2 if needed for at least 5 min post extubating one! 11. Allow patient to sit in position of their choice, do not flight them, place in carrier if needed or move to floor 31 SIGNS OF FULL RECOVERY = 5 THINGS! ANESTHETISTS MUST STAY WITH PATIENT UNTIL: 1. Good/optimal mentation. 2. Holding head up on own, & sternal. 3. All Vitals Normal. & remain normal (temp will decline after active warming normal if not mobile!) 4. Pain Controlled. 5. Dry & comfortable in kennel/recovery room. 32 COMMON ERRORS WITH PATIENTS 1. Traumatic intubation 2. over pressure 3. pressing flush valve 4. screw closed APL 4. Poor Depth Recognition 5. Poor panoramic view of vitals 6. Too much movement on ETT or breathing circuit 7.  1. ERROR: RUSHED OR TRAUMATIC INTUBATION  Must Pre-Oxygenate 5 min with mask or flow by  Induction is all about ensuring an appropriate pre-med effect, and the titration & timing of the induction agent  Administer drugs over 1-2min to induce (I.e., administer agent to effect)  Must move patient from stage I to stage II plane I/II rapidly  Intubation: obtain a view of the larynx with proper techniques  Apply lidocaine for cats on ASAP  Your instructor will ensure you have the best view for intubation  Upon visualization decide on ETT tube size to insert – start w/ biggest & work down  Do not touch the laryngoscope on the epiglottis! Tongue only  Prompt smooth and gentle intubation, there should be no resistance  Use bevel of ETTube tip to your adv to slide through open arytenoids (during exhalation)  Watch as you do it, close one eye if needed to line up your view  Confirm with capnography and secure tube (tie around tube & muzzle/head) 2. ERROR: OVER PRESSURE IPPV  IPPV MAX on manometer  LET GO of EVERYTHING IF YOU HIT THIS PRESSURE  Max 20cmH2O dogs, Max 15cmH2O for cats (okay during MOV Cuff inflation)  Ensure your EYES are on the manometer when spring-closing APL valve  NEVER thread close an APL for an IPPV *if there is no other option keep your hand on the APL until it is fully open.  For “bagging” and managing ventilation/ETCO2 use a slightly lower pressure:  Dogs 15-18 cmH O 2  Cats 10-12 cmH 0 2  OKAY to give little breaths too! Such as 10cmH2O dog or 5 cmH2O cats  Breaths should be natural: 1-2 second inhale, 2-4second exhale 3. ERROR: PRESSING FLUSH VALVE  NEVER b/c  Intermediate pressure (50psi) – too high!!!  High volume (35-75L/min) – too much!!!  = BAROTRAUMA  Is there an EMERENCY and you need to clear ISO from the SYSTEM?  Disconnect patient, plug end to avoid WAG, and then flush  WHAT TO DO if TEMPTED to press it (e.g., flat bag)?  Crank the O2 on the flow meter   Intermediate pressure (50psi) – too high!!!  High volume (35-75L/min) – too much!!! In both NBR & BR a closed APL will ALWAYS increase pressure in breathing system as fresh gas flow continues into circuit 4. ERROR with no means of SCREWING CLOSED entering OR SEMI the scavenge. CLOSED/OPEN APL Leads to barotrauma and or cardiorespiratory arrest and death  5. ERROR: TOO MUCH MOVEMENT ON ETTUBE OR WITH THE BREATHING CIRCUIT  NEVER step over or go under a breathing circuit  Patient positional changes, transfers, patient movement:  Communicate with team  Hold head & ETT secure if circuit needs to be moved  Disconnect the breathing circuit if needed  Careful of exhaled WAG, and hypoxic (patient breathing room air during hypoventilation)  6. ERRORS: POOR DEPTH RECOGNITION  Patients are at risk if they are in an inappropriate plane:  Risks:  Movement  Inappropriately light for procedure (e.g. plane I for a surgical procedure vs plane II).  Pain increases MAC and may require more analgesia to stay at plane  Hypotension (too deep)  Hypoventilation (too deep)  Overdose (respiratory, cardiac arrests)  CLASSIFICATIONS OF DEPTH: STAGES AND PLANES OF ANESTHESIA From Stage I  Stage IV there is a progressive decrease in pain perception, motor coordination, consciousness, reflex responses, muscle tone, and cardiopulmonary function  Stage 1 (Stage of voluntary excitement)  Stage 2 (Stage of involuntary excitement) YIKES AVOID WITH PROMPT INDUCTION  Stage 3 (Stage of surgical anesthesia) & Planes I, II, III and IV  Only OKAY to begin surgery IF in Plane II (Plane I too light for surgical procedures!)  Stage 4 (Stage of anesthetic overdose) 40  THE IDEAL ANESTHETIC DEPTH FOR SURGERY/NOXIOUS STIMULI  Non-responsive to surgical stimulus = stage 3 plane 2  Weak palpebral reflex (sometimes absent okay)  Eyeballs rotated ventro-medially  Weak jaw tone (some tone present though when opened to full potential)  Weak pedal  Weak anal tone (more LA)  Stable autonomic reflexes (RR, HR, BP, Temp) 7. COMMON ERRORS….NOT MONITORING OR KNOWING HOW TO MONITOR FLUID ADMINISTRATION  Review & prepare for recording keeping of IVF  Poor IVF fluid monitoring LEADS TO inadequate or overdosing IVF  Ensure you read the bag -not just the pump or just by doing the math on the record  Ask yourself what is the hourly rate? And then divide by 4 or 6 to know what they should have received in 10 or 15min for example.  Check IVC frequently  Check for facial edema  Skin edema (giggly?) Dogs 5mL/Kg/hr Dogs Hypotension IVF Bolus 10 mL/kg STAT Cats 3mL/kg/hr Cat Hypotension IVF Bolus 5 mL/kg STAT IV FLUIDS RATES 8. PANIC OR BROWN OUTS  Communicate with team & instructor  Start with what you know  This is a learning environment  Don’t expect mastery level!  Talk it through if you need to before  Communicate/warn team if experiencing debilitating anxiety, or panic is occurring – we will support you  HUM, Box Breath  please let someone know if you feel unwell or if you may faint  Please eat well prior to lab  Instructors may take over if patient is unsafe – don’ take it personally, it likely has nothing to do with you.  It will be okay!  The negative feelings will PASS! COMMON PATIENT PROBLEMS (ANESTHETIC COMPLICATIONS) X4 H’s: Hypoventilation, Hypotension, Hypothermia, Hemorrhage X1 P: Pain & Species Specifics: e.g. regurgitation +/- aspiration, laryngospasm COMMON ANESTHETIC COMPLICATIONS “4 H’S AND 1 P’ SPECIES SPECIFIC 1. HYPOTENSION – 1. REDUCE ISO (*IF POSS), 2. DOGS – REGURGITATION, ASPIRATION IVF BOLUS 3. BP DRUGS. CATS – REGURGITATION, ASPIRATION, 2. HYPOVENTILATION – 1. GIVE IPPV 2. REDUCE LARYNGOSPASM, DIFFICULT ISO/RESP DEPRESSANT DRUGS WHEN INTUBATION POSSIBLE 3. HYPOTHERMIA – ACTIVELY WARM, REDUCE OTHER (FOR BOTH DOG & CAT): VASOD BRADYCARDIA – PROVIDE 4. HEMORRHAGE – MANAGE BP & REPLACE LOSS ANTICHOLINERGIC 5. PAIN – PROVIDE ADEQUATE ANALGESIA ARRYTHMIAS – TREAT CAUSE, PROVIDE DRUGS CAUSES OF HIGH HEART RATE  Inadequate anesthetic depth – check depth don't assume!  Pain – consider last analgesia, what surgeon is doing, type of pain...  Hypotension – treat!  Blood loss and shock  Low oxygen – Hypoxia or hypoxemia  Hypercapnea  Anticholinergics and cyclohexamines 48 CAUSES OF LOW HEART RATE  CNS Depressant effect of most anesthetics  Drugs that directly reduce HR: Alpha - 2 agonists and opioids  Excessive anesthesia depth  An Adverse effects of other drugs 49 BODY TEMPERATURE LOSS CONSEQUENCES DURING ANESTHESIA  Prolongs anesthetic recovery  Reduces anesthetic requirement (MAC reduction)  Predisposes patient to anesthetic overdose  Shivering during recovery will increase oxygen demands  Supply 100% O2 flowby!  Shivering also contributes to increased pain!  Can causes CNS depression and heart malfunction 50 MINIMIZE OR MANAGE HEAT LOSS DURING ANESTHESIA  PREVENTION, blankets and warming devices ASAP  Avoid cold prep (warm it in incubator)  Barrier between patient and table top  Warm IV fluids to ~100° C (37.5° F)  Forced warm air blanket  Or Circulating warm water blanket  Warm water bottles/disc (CAUTION)  Infrared heating lamps  Warmed fluids for abdominal cavity flush  Socks/wraps on feet! 51  A. Hypotensive and good plane of anesthesia B. Hypotensive and light plane (no movement) of anesthesia C. Light plane – slight movement D. Responsive/Painful SCENARIO E. Tachycardic S F. Tachypnea G. Won’t Stay Asleep H. Too Deep I. Capnogram flat line/no detection J. Hypercapnic / Hypoventilating K. Regurgitation L. Larygospasm M. Bradycardic and normal tensive N. Bradycardic and hypotensive O. Dyspnea P. Pale MM END. STANDARDS/NORMS ARE LISTED NEXT & ALL SLIDES TAKEN FROM ANES I MONITORING LECTURES  Indicators of Circulation: Capillary Refill Time (CRT) ◦Indicates peripheral tissue blood perfusion, (can mislead you however) ◦Slow may result from epinephrine release, low blood pressure, hypothermia, cardiac failure, excessive anesthetic depth, blood loss, pain, shock, ◦Results in reduced temperature of affected part(s) CRT > 2 seconds: prolonged, decreased perfusion possibly due to hypovolemia ◦(dehydration) or peripheral vasoconstriction (e.g. during shock) CRT < 1 second: normally accompanied by bright red mucus membranes; septicemia, hyperthermia (vasodilation) NORMAL CRT = 1 – 2 seconds 54  SpO2 % Interpretation Should be interpreted based on inspired O2 fraction (FiO2) NORMAL SpO2 VALUES are between 95 – 100%PaO2 Breathing Room Air (FiO2 = 0.21) SpO2 = >95 % hypoxic is when SpO2 = 45 Low ETCO2? assess patient, depth, O2…recall rapid decline or 1 mm Hg) Exhausted / malfunctioning CO2 absorber Inadequate inspiratory flow (T-tube) Insufficient expiratory time Faulty (sticky) expiratory valve Obstructed! ETT, airway, or circuit OR BRONCHOSPASM Shark Fins =/ malfunctioning Exhausted BAD CO2 absorber Inadequate inspiratory flow (T-tube) Insufficient expiratory time Faulty (sticky) expiratory valve Esophageal Intubation if Cardiac Output is Good Esophageal Intubation (once confirmed patient breathed or IPPV given once attached to ADS, if you see no trace the esophagus is likely intubated) - No CO2 sensed or very minimal amounts - capnograph is the best monitor to confirm intubation is in the trachea Esophageal Stethoscope Copyright © 2017 by Elsevier, Inc. All rights reserved. 61 Esophageal Stethoscope  Operator end same a regular stethoscope – can not be submerged in H2O or cleaner  Attaches to a catheter placed down the esophagus  Inserted to the point of maximal (sound) intensity (PMI)  Around the 4-5th rib  Must be measured to ensure you do not accidently enter the stomach  If the stomach is entered, the sphincter will open allowing content to travel up the esophagus and potential down the trachea!  Technique: Measure, lubricate, follow dorsal midline of the maxilla, and insert to correct distance  A great tool during anesthesia as it provides heart and lung sounds  A confident way to obtain heart rate in any environment, esp. loud environments or a patient who has a lot of draping or surgery occurring on the thorax  Also great for when monitoring devices fail or we need to confirm accuracy 62 Heart Rates 100 63 Peripheral Arterial Pulse & Strength Arterial Pulse Palpation Sites (Small Animals) Femoral Dorsal pedal Metatarsal Digital Auricular Lingual Coccygeal 64 Common Tech Errors in BP measurements Cuff size must be 40% for dogs & 30% for cats of the circumference of their limb or tail where the cuff is to be placed. Never place cuff over joints  Cuff overly wide  falsely low reading  Cuff overly small or narrow  falsely high reading  Cuff not place snugly  Falsely elevates reading  Cuff placed over a joint  Less likely to compresses artery  Hole in cuff  Pressure leaks too fast to reliably record  Cardiac arrhythmias  erratic reading  Taping an Oscillometric cuff (NEVER!)  okay to tape closed a doppler cuff though  Reference: Cardiology for Veterinary Technicians and Nurses – H. Edward Durham Jr. 65 Mean arterial pressure (MAP) ◦ Average pressure through the cardiac cycle ◦ Main & best indicator of tissue perfusion ◦ A mathematical calculation BP NORMALS: 66 Hypotension: must keep BP above these values! Small animal: < 50kg Large Animal: > 50kg Immediately report if your patient is trending towards, AT or BELOW these values These are our minimal acceptable BP values 60 70 80 90 67  3 electrodes most common - black, white, & red * USED in Lab  i.e., x2 electrodes = 1 lead  4 electrodes have a green electrode, in addition to the black, white, & red. 68 In Ensure to set ECG machine to display Lead II. Ensure the size of the complexes are not too small and not too large that they off the screen. Smoke (black) over Fire (red) WHITE ON RIGHT – rhymes right upper quadrant - foreleg LL for LEFT LEG - alliteration Red on left hindleg 69 ECG Common causes of anesthetic-related arrhythmias  Inadequate anesthesia / analgesia  Bradycardia  Tachycardia  Hypoxemia  Hypercapnea  Hypotension  Hypo/hyperthermia  Electrolyte abnormalities (potassium and magnesium)  Oculo-cardiac reflex 70