1. ANESTHETIC PROBLEMS AND EMERGENCIES
The Role of the Veterinary Technician in Emergency Care

2. ANESTHETIC PROBLEMS AND EMERGENCIES
Anesthetic problems will inevitably occur at some
point in your career. No anesthetic experience is
the same, so beware of the false sense of security!

3. ANIMALS THAT WILL NOT STAY ANESTHETIZED
Animals won’t stay anesthetized
Check vaporizer setting
Check level of anesthetic in the vaporizer
Proper ET tube placement or air leakage around it
Patient apnea
Shallow respirations
Proper assembly of anesthetic machine with tight connections
Adequate oxygen flow
Anesthetic machine/vaporizer is working properly
Agonal breathing vs. light plane breathing

4. ANIMALS THAT ARE TOO DEEPLY ANESTHETIZED
Animals are too deeply anesthetized
<6 bpm; shallow respirations, dyspnea
Pale/cyanotic mucous membranes
Capillary refill time >2 seconds
Bradycardia
Weak pulse; systolic blood pressure <80 mm Hg
Cardiac arrhythmias; irregular QRS complexes or VPCs
Hypothermia
Absent reflexes
Flaccid muscle tone
Dilated pupils

5. TREATING EXCESSIVE ANESTHETIC DEPTH
ADJUST THE VAPORIZER:
NOTIFY THE VETERINARIAN:
BAG THE ANIMAL
1. Close the pop-off valve
2. fill the reservoir bag with oxygen
3. gently squeeze the bag until the patient’s chest rises slightly (15-20 cm H2O)
4. Repeat until animal shows signs of recovery

6. PALE MUCOUS MEMBRANES Pale mucous membranes Preexisting conditions
Blood loss during surgery
Anesthetic agent that causes vasodilation and hypotension
Hypothermia
Pain

7. TREATMENT OF PALE MUCOUS MEMBRANES
Ascertain the animal’s anesthetic depth:
HR, RR, pulse quality, CRT
Consult the veterinarian
Fluids, blood transfusion

8. Anesthetic Problems and Emergencies (Cont’d)
Prolonged capillary refill time (>2 seconds)
Blood pressure cannot adequately perfuse superficial tissues
May result from conditions present prior to induction
May be secondary to blood loss during surgery
May be seen in animals in deep anesthesia

9. DYSPNEA AND/OR CYANOSIS
DYSPNEA: respiratory difficulty
CYANOSIS: bluish coloration of the mucous membranes indicating inadequate tissue oxygenation
Assessment
Respiratory character and volume
Depth of anesthesia
Associated with pain
Proper ET tube placement
ET tube blockage
Oxygen saturation
Arterial or end-tidal CO2

10. Treatment of cyanosis/dyspnea
1. Check O2 flow meter
2. Turn off vaporizer and begin to bag the patient (IPPV)
If the anesthetic machine is unavailable, an Ambu bag can be used to deliver room air
3. Reintubate if necessary
4. Continue until patient improves
5. Close monitoring to ensure that cardiac arrest does not occur
Radiographs and thoracocentesis might be needed

11. TACHYPNEA TACHYPNEA: rapid respirations CAUSES: Surgical stimulation
Commonly seen with opioid use
Associated with light anesthesia accompanied by tachycardia and spontaneous movement
May be seen in hyperthermic animals

12. TREATMENT OF TACHYPNEA
CHECK ANESTHETIC DEPTH
Is the animal too light?
CAPNOGRAPH READING
Obese patients
Assist or control ventilation

13. RESPIRATORY ARREST Cessation of respiratory efforts
Not all cases require immediate action by the anesthetist:
Cessation of respiratory efforts
Can lead to cardiac arrest
Temporary arrest
May follow injection of respiratory depressants or following a period of prolonged bagging
Evaluate other vital signs
HR/pulse quality:
MM:
ECG
Pulse oximeter reading:

14. Respiratory arrest (Cont’d)
True arrest
Requires immediate action
Can result from anesthetic overdose, cessation of oxygen flow, or preexisting respiratory disease
May be preceded by dyspnea or cyanosis and abnormal vital signs
May use Ambu bag, mouth-to-ET tube, or mouth-to-muzzle resuscitation

15. Use of an Ambu Bag

16. TREATMENT OF TRUE RESPIRATORY ARREST
1. NOTIFY THE VETERINARIAN
2. Turn off the vaporizer
3. Place ET tube if not already done
Emergency tracheotomy?
4.Monitor for cardiac arrest
5.Restore oxygen flow and begin bagging the patient
6. Continue bagging every 5 seconds until vital signs improve
7. Administer shock fluids- Dr. can decide on Dopram or reversal
8. Preserve warmth

17. CARDIAC ARREST No heartbeat is auscultated or palpated
Normal QRS complexes are absent
No arterial pulse and blood pressure <25 mm Hg
Gray or cyanotic mucous membranes
Widely dilated pupils, no corneal reflex
Agonal breathing
Some prior warning is usually present
Respiratory distress or arrest, cyanosis/dyspnea, prolonged capillary refill time, arrhythmia

18. Updated with information from the ACVECC-RECOVER Study 2012
CPR
CardioPulmonary Resuscitation
Updated with information from the ACVECC-RECOVER Study 2012

19. Anesthetic Problems and Emergencies
Cardiac arrest with CPCR (cardio-pulmonary cerebrovascular resuscitation)
A = airway
B = breathing
C = circulation
D = drugs
E = ECG
F= Fluids
Circulation is the most important step so the correct order is CABDE

20. CPR Human Medicine Veterinary Medicine
Cardiac arrest: 330,000 people per year die
Survival to discharge:
Out-of-hospital arrest: <6.4%
Veterinary Medicine
Total arrest numbers unknown
In-hospital-arrest:
Dogs 4%
Cats 4-9.6%

21. The most successful CPR is one that is averted!
PREVENTION
The most successful CPR is one that is averted!
Know which patients are risk.
Know the warning signs.

22. Risk Factors Cellular hypoxia Hypercarbia Vagal stimulation
Arrhythmias
Severe anemia
Acid-base abnormalities
Electrolyte abnormalities
Anesthesia
Trauma
Systemic and metabolic diesease

23. Warning signs
Changes in respiratory rate and character
Weak irregular pulses
Bradycardia
Hypotension
Cyanosis
Hypothermia

24. Preparedness/Readiness
Time is critical
To Increase chances of success…
Early recognition
Know patient’s code status
Personnel
Dedicated space
Equipment

25. Recognition of arrest Loss of consciousness No respirations
No palpable pulses
Pupils fixed and dilated
CRT prolonged or absent
MM pale, grey, cyanotic

26. Who should be resuscitated?
Patients with reversible disease
When doubts exist perform CPR
Discuss and educate client at admission!

27. Personnel responsibilities
There is a critical 4 MIN window to restore oxygen delivery to the brain!
Team Effort: Doctors and Technicians (5 techs 1 doctor)
Central person making decisions (DVM)
Chest compressions
Manual ventilation
Drug administration
Setting up monitoring equipment
Recording events

28. Dedicated space
Hard Surface
Oxygen source

29. Crash Cart Cuffed endotracheal tubes Laryngoscope
4-6 sizes
Laryngoscope
Syringes, needles of various sizes
Catheters: Intravenous, intraosseous, red rubber
Defibrillator
Drugs
Epinephrine, atropine, vasopressin
Naloxone
Small surgery pack
Suction unit

30. Phases of Resuscitation
Basic Life Support
ABC’S
Advanced Life Support
ABC plus D: Drugs & Defibrillation
Post-Arrest: Prolonged Life Support

31. ABC’s Airway Should have 4-6 sizes of cuffed ET tubes available
Laryngoscope
Make sure airway is clear
Suction airway if necessary
Capture and secure airway!!

32. CARDIAC ARREST - ABCDEF
AIRWAY and BREATHING;
IMMEDIATELY CALL FOR HELP, NOTE THE TIME!
An Endotracheal tube must be placed!
Begin bagging at 1 breath every seconds (1:5 breath to compressions)
Do not overinflate

33. Breathing Utilization of ambu bag connected to oxygen source
Provide manual ventilatory support
Ventilation of dogs and cats with CPA at a rate of 10 breaths per minute with a tidal volume of 10ml/kg and an inspiratory time of 1 sec is recommended.

34. Circulation External chest compressions Positioning
Thoracic pump theory
Cardiac pump theory
Positioning
Lateral recumbency
Firm surface
Medium and large dogs
Small dogs and cats

35. CARDIAC ARREST - ABCDEF
CIRCULATION – cardiac compressions should be initiated
Compressions manually force blood through the heart and into tissues
POSITIONING: right side down with legs toward the compressor
LARGE DOGS: The heel of the compressor’s hand should compress the chest against a firm object placed under the dog’s chest just behind the elbow. Also, dog can be placed in dorsal recumbency and compression applied to the caudal 1/3 of the sternum

36. CARDIAC ARREST - ABCDEF
Medium sized dogs: The chest is compressed between two hands, one underneath the chest and the other at the 5th intercostal space over the heart itself.
Small dogs or cats: compression applied using the thumb to compress the chest against the fingers of the same hand.

37. Circulation Cardiac compressions
Most important factor is return of spontaneous circulation (ROSC)
Cardiac compressions
Each compression should produce a palpable femoral pulse
Rate of compressions : / minute
Compressions should be continuous
Allow full chest wall recoil
30-50% chest compression depth
1:1 ratio compression/relaxation
Change compressor every 2 minutes

38. Circulation (Cont’d)
Bag the patient every seconds
Simultaneously with compressions
Some results should be seen within 2 minutes
Internal compressions may be necessary
Resuscitation is unlikely to be successful after 15 minutes
Once spontaneous cardiac contractions are established, continue bagging until spontaneous breathing is established (several hours)

39. These patients are not on their right side- boooo

40. Indications for open chest CPR
Owner wishes??
Thoracic trauma
Pericardial fluid
No response to CPR after 3-5 minutes
Chest or abdominal surgery

41. ABC plus D Drugs Defibrillator Doppler Advanced Life Support
Veterinarian authorizes dosage, route, and nature of drugs

42. Drugs Epinephrine – 0.01 mg/kg Atropine – 0.05 mg/kg
Alpha 2-adrenergic stimulator: vasoconstriction
Give every 3 to 5 minutes during CPR
Atropine – 0.05 mg/kg
Anticholinergic parasympatholytic: Increases HR
Asystole and PEA
Vasopressin – 0.8 u/kg
Peripheral vasoconstriction
Dilation of cerebral vasculature
Asystole, prolonged arrest
Dopamine or dobutamine
Increase force and rate of cardiac contractions

43. Drug Dose Chart
From:

44. Drug admnistration routes
IV (intravenous)
IT (intratracheal)
Double dose of drug
Never give Na bicarb IT
IO (intraosseous)
IC (intracardiac) NOT RECOMMENDED
Risk of coronary vasculature laceration in closed-chest
OK in open-chest

45. ECG
Monitor/Assess
Rhythm
Electrical activity

46. Common Initial Arrest Rhythms
Ventricular fibrillation PEA (pulseless electrical activity) Asystole

47. Asystole Most common arrest rhythm NO drugs have proven effective
Vasopressin shows some promise
Continue CPR or stop

48. Pulseless Electrical activity
Electrical activity but no myocardial contraction
Formerly know as EMD (electrical mechanical dissociation)
NO drugs proven effective
Continue CPR or stop

49. Ventricular Fibrillation
Two forms
Coarse
Higher amplitude more orderly appearance
Easier to convert with defibrillation
Fine
Lower amplitude, complete lack of organization
Carries poorer prognosis, more difficult to convert
Can be mistaken for asystole
Recommended treatment: Immediate defibrillation

50. Advanced Life Support: cont
Defibrillation
One shock
External:
4-6 J/kg Monophasic
2-4 J/kg Biphasic
Internal: j/kg
No alcohol(ecg)

51. Auscultation, palpation of pulses
Monitoring
ETCO2
Doppler on cornea
~Cerebral blood flow
Auscultation, palpation of pulses

52. Advanced life support: cont- Fluids
IV fluids (crystalloids)
IF EUVOLEMIC:
*DO NOT GIVE SHOCK DOSES*
Decreased CPP
Increased right atrial pressure relative to aortic pressure
If hypovolemic
Shock dose: 90ml/kg dogs, 40-60ml/kg cats
Start with ¼ shock dose

53. Monitor cardiovascular and respiratory function
Blood pressure, blood gases, pulse oximetry, ECG, capnography
Drug and fluid therapy varies
Assess brain function
Repeat arrest within 24 hours is common
Following successful ROSC, other conditions may arise
Pulmonary or cerebral edema

54. Wrap Up Prevention Preparedness Early recognition
Know patient’s code status
Dedicated space, personnel, equipment
KNOW YOUR ABC’s!

55. Other occurrences during surgery but not necessarily an emergency
Regurgitation during anesthesia
A passive process under anesthesia
No retching, just fluid draining from animal’s mouth or nose
Stomach contents may be aspirated into respiratory tract
Most common occurrence in head-down surgical positions and in ruminants
Treatment
Immediate placement of cuffed ET tube
Clean out regurgitated material with suction

56. Post op complications Vomiting during or after anesthesia
Common in brachycephalic dogs or nonfasted animals
An active process usually accompanied by retching
Usually occurs as the animal is losing or regaining consciousness
Signs
Airway obstruction leading to dyspnea/cyanosis, bronchospasm
Treatment
Intubation and suction if unconscious
Lower head and clean oral cavity if conscious

57. Seizures
Seen with ketamine administration, after diagnostic procedures (myelography), or preexisting conditions
Signs
Spontaneous twitching; uncontrolled movements of head, neck, and limbs; opisthotonus; triggered by a stimulus
Treatment
Reduce stimuli, postoperative analgesia, diazepam or propofol, monitor for hyperthermia

58. Seizures should be differentiated from excitement
Seen after barbiturate anesthesia or high opioid doses, as spontaneous paddling and vocalization
Treatment may not be necessary
Sedatives may help
Naloxone can reverse opioids
Seizures should be differentiated from excitement

59. Dyspnea in cats
Dyspnea is usually caused by laryngospasm sometimes triggered by removal of the ET tube
Laryngeal edema may result from repeated intubation attempts
May breathe with an audible stertor (wheeze) during inspiration
Differentiate from growling during expiration
May resolve itself or may need oxygen administration via facemask, intubation, or a tracheotomy
Is easier to prevent than treat

60. Dyspnea in dogs Breed-related Airway obstruction
Brachycephalic dogs
Airway obstruction
Anatomy, foreign objects, postsurgical tissue swelling
Humidified oxygen can be delivered to an awake animal
By facemask, nasal cannula, E-collar, or oxygen cage/tent