Download 11a CPR

ANESTHETIC PROBLEMS
AND EMERGENCIES
The Role of the Veterinary Technician
in Emergency Care
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!
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
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
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
PALE MUCOUS MEMBRANES
 Pale mucous membranes
 Preexisting conditions
 Blood loss during surgery
 Anesthetic agent that causes vasodilation and hypotension
 Hypothermia
 Pain
TREATMENT OF PALE MUCOUS MEMBRANES
 Ascertain the animal’s anesthetic depth:
 HR, RR, pulse quality, CRT
 Consult the veterinarian
 Fluids, blood transfusion
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
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
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
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
TREATMENT OF TACHYPNEA
 CHECK ANESTHETIC DEPTH
 Is the animal too light?
 CAPNOGRAPH READING
 Obese patients
 Assist or control ventilation
RESPIRATORY ARREST
 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:
 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
USE OF AN AMBU BAG
TREATMENT OF TRUE RESPIRATORY ARREST
 1. NOTIFY THE VETERINARIAN
 2. Turn off the vaporizer
 3. Place ET tube if not already done
 Emergency tracheotomy?
http://www.youtube.com/watch?v=3doQewrHdhQ
 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
CARDIAC ARREST
 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
CPR
CardioPulmonary
Resuscitation
Updated with information from the
ACVECC-RECOVER Study 2012
http://www.acvecc-recover.org/
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
CPR
Human Medicine
 Cardiac arrest: 330,000 people per year die
 Survival to discharge:
 Out-of-hospital arrest: <6.4%
Veterinary Medicine
 Total arrest numbers unknown
 Survival to discharge:
 In-hospital-arrest:
 Dogs 4%
 Cats 4-9.6%
PREVENTION
The most successful CPR is one
that is averted!
Know which patients are risk.
Know the warning signs.
RISK FACTORS
 Cellular hypoxia
 Hypercarbia
 Vagal stimulation
 Arrhythmias
 Severe anemia
 Acid-base abnormalities
 Electrolyte abnormalities
 Anesthesia
 Trauma
 Systemic and metabolic diesease
WARNING SIGNS
Changes in respiratory rate and
character
Weak irregular pulses
Bradycardia
Hypotension
Cyanosis
Hypothermia
PREPAREDNESS/READINESS
 Time is critical
 To Increase chances of success…
 Early recognition
 Know patient’s code status
 Personnel
 Dedicated space
 Equipment
RECOGNITION OF ARREST
 Loss of consciousness
 No respirations
 No palpable pulses
 Pupils fixed and dilated
 CRT prolonged or absent
 MM pale, grey, cyanotic
WHO SHOULD BE RESUSCITATED?
 Patients with reversible disease
 When doubts exist perform CPR
 Discuss and educate client at admission!
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
DEDICATED SPACE
Hard Surface
Oxygen source
CRASH CART
 Cuffed endotracheal tubes
 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
PHASES OF RESUSCITATION
Basic Life Support
ABC’S
Advanced Life Support
ABC plus D: Drugs & Defibrillation
Post-Arrest: Prolonged Life Support
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!!
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 10-12 seconds (1:5 breath to
compressions)
 Do not overinflate
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.
CIRCULATION
External chest compressions
 Thoracic pump theory
 Cardiac pump theory
Positioning
 Lateral recumbency
 Firm surface
Small dogs and cats
Medium and large dogs
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
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.
CIRCULATION
 Most important factor is return of spontaneous circulation
(ROSC)
Cardiac compressions
 Each compression should produce a palpable femoral pulse
 Rate of compressions : 100-120/ 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
 Circulation (Cont’d)
 Bag the patient every 10-12 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)
THESE PATIENTS ARE NOT ON THEIR
RIGHT SIDE- BOOOO
INDICATIONS FOR OPEN CHEST CPR
Owner wishes??
Thoracic trauma
Pericardial fluid
No response to CPR after 3-5 minutes
Chest or abdominal surgery
ADVANCED LIFE SUPPORT
ABC plus D
Drugs
Defibrillator
Doppler
Veterinarian authorizes dosage, route, and
nature of drugs
DRUGS
 Epinephrine – 0.01 mg/kg
 Alpha 2-adrenergic stimulator: vasoconstriction
 Give every 3 to 5 minutes during CPR
 Atropine – 0.05 mg/kg
 Anticholinergic parasympatholytic: Increases HR
 Give every 3 to 5 minutes during CPR
 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
DRUG DOSE CHART
From: www.ACVECC-RECOVER.org
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
ECG
Monitor/Assess
Rhythm
Electrical activity
COMMON INITIAL ARREST RHYTHMS
Ventricular fibrillation
PEA (pulseless electrical activity)
Asystole
ASYSTOLE
Most common arrest rhythm
NO drugs have proven effective
Vasopressin shows some promise
Continue CPR or stop
PULSELESS ELECTRICAL ACTIVITY
Electrical activity but no myocardial contraction
 Formerly know as EMD (electrical mechanical dissociation)
NO drugs proven effective
Continue CPR or stop
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
ADVANCED LIFE SUPPORT: CONT
Defibrillation
One shock
External:
4-6 J/kg Monophasic
2-4 J/kg Biphasic
Internal: 0.2-1 j/kg
No alcohol(ecg)
MONITORING
ETCO2
Doppler on cornea
~Cerebral blood flow
Auscultation, palpation of pulses
ADVANCED LIFE SUPPORT: CONTFLUIDS
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
 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
WRAP UP
 Prevention
 Preparedness
 Early recognition
 Know patient’s code
status
 Dedicated space,
personnel,
equipment
 KNOW YOUR ABC’s!
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
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
 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
 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
 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
 Dyspnea in dogs
 Breed-related
 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