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 Oxygen ET tube  Double-check the patient Respirations  Rapid and shallow?  Apneic?

3. ANIMALS THAT ARE TOO DEEPLY ANESTHETIZED  Respirations Rate: Character:  Mucous membranes:  Capillary refill time:  Heart rate: bradycardia

4. ANIMALS THAT ARE TOO DEEPLY ANESTHETIZED  Pulse quality:  ECG:  Temperature:  Muscle tone:  Pupils:

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. RESPIRATORY ARREST -is it true?  Patient is not breathing on their own  Doesn’t always require action: 1. 2.  Assess other vitals:

7. RESPIRATORY ARREST  True respiratory arrest: Warning signs:  Begin manually ventilating  Continue until vitals improve…  Then give them a chance! *What if you don’t have an anesthetic machine?

8. 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

9. CARDIAC ARREST  Signs it’s here: No heart beat auscultated No palpable arterial pulse MM gray BP <25 mm Hg Agonal breath Initiate CPCR: a team effort! ASK FOR HELP

10. CARDIAC ARREST – ABCDE???  There is a critical window to restore oxygen delivery to the brain  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

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

12. CARDIAC ARREST - CABDE  Circulation  Compression 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 to 1/2 the diameter of the chest wall Should feel a femoral pulse with each compression Will also stimulate a little gas exchange  Doppler probe on the eye to assess pulses

13. CARDIAC ARREST - CABDE  Compressions and bagging should be administered simultaneously.  Switch every two minutes **Circulation should take priority over breathing, if working alone**  What are you looking for?

14. 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!

15. 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

16. CARDIAC ARREST - CABDE  Airway and Breathing  Intubate  100% oxygen  Ventilate every 10 seconds

17. CARDIAC ARREST - CABDE  Drugs : Epinephrine Dopamine/dobutamine Atropine Lidocaine  Routes: IV- drugs, fluids IT – drugs IC – last resort for drugs  Stops compressions, and can damage myocardium

18. 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.

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

20. Recovery Period Problems  Regurgitation   Vomiting  Solutions: FASTING Injectables Quick intubation with cuffed ET tubes  Leaving tube in place until P has swallow reflex

21. Recovery Period Problems  Seizures- spontaneous, uncontrolled twitching Differentiate from reverse excitement phase and/or pain Animals that might have a rough recovery?  Solutions: Remove external stimuli Diazepam IV; possibly PR Propofol? Monitor for hyperthermia

22. 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  Lidocaine initially  Trauma to tracheal opening? Solution: Check MM, SpO2 and positioning  Provide oxygen  Re-intubate if patient is crashing  What if you can’t intubate?

23. Recovery Period Problems  Dyspnea- most common cause of post-Ax death Dogs: extra tissue blocking tracheal opening  Which breeds more susceptible? 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

24. Recovery Period Problems  Prolonged recovery phase Individual susceptibility to Ax drugs Hypothermic Prolonged anesthesia; excessive depth Prevention : fluid therapy during sx; start warming ASAP Solution : Warm them up! Reversals if available

25. Reading Assignment Other reasons for the clinical signs of being too deeply anesthetized: Page 336-337 (Start at Pale MM, stop at Respiratory Arrest) I would suggest reviewing the chapter key points and Procedures 12-1 through 12-11 as well.