1. Response to Anesthetic Problems and Emergencies We are going to talk about your response to:  Depth of anesthesia issues  Cardiac arrest  Recovery period problems

2. ANIMALS THAT WILL NOT STAY ANESTHETIZED  Double-check equipment Vaporizer  Empty? Off? Oxygen  Rate to low? ET tube  Too small in diameter?  Double-check the patient Respirations  Rapid and shallow can lead to not enough anesthetic gas exchange  Check capnograph

3. ANIMALS THAT ARE TOO DEEPLY ANESTHETIZED  Respirations Rate: 6 or less/min Character: shallow or agonal  Mucous membranes: pale or cyanotic  Capillary refill time: >2 sec  Heart rate: bradycardia Cats- <100 bpm Dog- <60 bpm

4. ANIMALS THAT ARE TOO DEEPLY ANESTHETIZED  Pulse quality: weak  ECG: VPCs or other arrhythmias  Temperature: <97°F; cold extremities  Muscle tone: flaccid  Pupils: dilated; absent PLR (gone anyway)

5. TREATING EXCESSIVE ANESTHETIC DEPTH  Lower vaporizer setting  Notify veterinarian  Manually ventilate the patient 1. Close the pop-off valve 2. Fill the reservoir bag with pure oxygen  May need to disconnect if flushing for a long time 3. Gently squeeze the bag until the patient’s chest rises slightly (not above 20 cm H 2 O) 4. Repeat until animal shows signs of recovery  Reversals, doxapram, fluids, warmth

6. CARDIAC ARREST A sudden cessation of effective ventilation and circulation.  Signs it’s coming: Cyanosis Respiratory arrest CRT > 2 sec Weak arterial pulse Very low BP readings Abnormal ECG tracing  VPCs  V-fibrillation  Asystole

7. CARDIAC ARREST  Signs it’s here: No heart beat auscultated No palpable pulse MM gray No PLR; no corneal reflex Respirations- only agonal Initiate CPCR: a team effort! ASK FOR HELP

8. CARDIAC ARREST – ABCDE???  There is a critical window to restore oxygen delivery to the brain How long do you have?  Ideally, 5 people would participate in the resuscitative efforts 1. Performs chest compressions 2. Bags the animal 3. Assess the pulse during compressions and the ECG when compressions are temporarily suspended 4. Draws up and administers drugs on the veterinarian’s orders 5. Maintains a record of procedure Can be done with less!

9. CARDIAC ARREST – CABDE  Circulation restoration is most important  Start compressions!  Positioning Slightly different based on size

10. CARDIAC ARREST - CABDE  Circulation  RATE: 1-2 times per second ~80 times per minute for a large dog ~120 times for small dogs or cats  Chest should be compressed ~1/3 the diameter of the chest wall Should feel a femoral pulse with each compression  Doppler probe on the eye

11. CARDIAC ARREST - CABDE  Compressions and bagging should be administered simultaneously. If you are alone, 10 compressions per 2 breaths. **Circulation should take priority over breathing, if working alone**

12. CARDIAC ARREST - CABDE  Can switch to internal massage after 2 mins What procedure would be performed? Invasive, but can get higher return of CO Prep between ribs 7-8  Defibrillation may be started Electric shock (J/kg) No alcohol if defibrillating!

13. CARDIAC ARREST - CBADE  Continue compressions until you have return of spontaneous circulation (ROSC)  Palpate pulse, continue ECG, auscultate continuously  Continue bagging after beat is back

14. CARDIAC ARREST - CABDE  Airway and Breathing  Intubate  Ventilate every 10 seconds

15. CARDIAC ARREST - CABDE  Drugs : Epinephrine Dopamine/dobutamine- increase force and rate of cardiac contractions Atropine Lidocaine  Routes: IV- drugs, fluids IT – drugs IC – last resort for drugs  Stops compressions, and can damage myocardium

16. CARDIAC ARREST - CABDE  E CG Periodically check for spontaneous contractions by discontinuing external compression Done by either palpating for a pulse or looking for QRS complexes on the ECG.

17. CARDIAC ARREST  After Care:  Common for patient to repeat arrest within 24 hours  Neurological tests needed  Must be monitored extremely close

18. Recovery Period Problems  Regurgitation  Active or passive? Occurs when?  Vomiting  Active or passive? Occurs when? Solutions: FASTING Injectable Quick intubation Cuffed endotracheal tubes Leaving tube in place until P can swallow

19. Recovery Period Problems  Seizures- spontaneous, uncontrolled twitching Differentiate from reverse excitement phase and/or pain  Solution: Remove external stimuli Diazepam IV; possibly PR Monitor for hyperthermia

20. Recovery Period Problems  Dyspnea- most common cause of post-Ax death *When is this most likely to occur? Cats: laryngospasms  reflex closure of trachea Prevention: extubate before reflex returns  Use lidocaine to intubate Solution: Check MM, SpO2 and positioning  Provide oxygen  Re-intubate if patient is crashing  What if you can’t intubate?  Patient will remain intubated until swelling goes down

21. Recovery Period Problems  Dyspnea- most common cause of post-Ax death Dogs: extra tissue blocking tracheal opening  Which breeds? Prevention: leave tube in as long as possible  Longer if the intubation was difficult  Monitor positioning after extubation Solution: Check MM, SpO2 and positioning  Provide oxygen  Re-intubate if patient is crashing  Corticosteroids?

22. Recovery Period Problems  Prolonged recovery phase Individual susceptibility to Ax Hypothermic Prevention : fluid therapy during sx Solution : Warm them up! Examples: forced air blower, rice socks, socks, reflective blanket, warmed towels, warm fluids, circulating water blanket, hair dryer…

23. Reading Assignment Other reasons for the clinical signs of being too deeply anesthetized: Page 336-337 (Start at Pale MM, stop at Cardiac Arrest) Problems That May Arise in the Recovery Period Pages 341-343 I would suggest reviewing the chapter key points and Procedures 12-1 through 12-11 as well.