Anesthetic Problems And Emergencies Flashcards
Why do problems arise?
Human error
Equipment error
Adverse effects
Patient factors
Human errors that may result in anesthetic problems
- Failure to obtain adequate history or perform a physical examination
- Lack of familiarity with the anesthetic machine or drugs used
- Incorrect administration of drugs
- Fatigue
- Inattentiveness
- Distraction
Examples of equipment failure or operator carelessness
- Carbon dioxide absorber exhaustion
- Failure to deliver sufficient oxygen to the patient
- Misassembly of the anesthetic machine
- Failure of the vaporizer and pop-off valve
- Endotracheal tube problems
Some patients are at increased risk for anesthetic complications because of Preexisting factors such as these
Old age
Organ failure
Recent trauma
Breed-related conformation
Why do geriatric patients have a reduced anesthetic requirement?
They have less reserve than younger patients
Like geriatric patients, these patients also require reduced doses of injectable agents
Pediatric patients
These patients are prone to hypothermia and hypoglycemia
Pediatric patients
What are the anatomic characteristics that make respiration difficult for brachycephalic dogs?
Have one or more anatomic characteristics that impede air exchange, including very small nasal openings, an elongated soft palate, and small diameter trachea
What should be done to brachycephalic dogs before induction?
Preoxygenate for 5 minutes before induction by gently restraining and administering oxygen through a face mask
Why should induction be rapid on brachycephalic dogs?
To gain control over the airway
What form of induction is preferred for brachycephalic dogs?
IV induction agents (propofol, ketamine-diazepam, methohexital) that are rapidly metabolized are preferred over mask induction
The Endotracheal tube that fits the trachea of a brachycephalic dog is larger or smaller than expected?
Smaller
Why should the Endotracheal tube be left in place for as long as possible in brachycephalic dogs?
The animal will maintain an open airway as long as the tube is in place
Brachycephalic dogs should be monitored for respiration difficulty particularly during this period.
Recovery period
Why should thiobarbiturates be used with extreme care in sighthounds?
Sighthounds show an increased sensitivity to anesthetic agents, particularly thiobarbiturates
Why do sighthounds have an increased sensitivity to thiobarbiturates?
Lack of body fat for redistribution of the drug
Inefficient hepatic metabolism of many drugs
What are the induction agents that can be safely used as alternatives to thiobarbiturates in sighthounds?
Diazepam and ketamine Methohexital Propofol Isoflurane Sevoflurane
Why are anesthetics not efficiently distributed to fat stores?
The blood supply to fat is relatively poor
What is the difference between the dose of an obese patient and a normal patient?
Obese dogs require lower doses of drugs on a per kg basis than normal dogs
How is the dose of anesthesia determined for obese patients?
The dose is determined according to(Their IDEAL body weight) a weight halfway between the normal breed weight an the actual weight
Pregnant animals presented for a C-section are at an increased or decreased anesthetic risk?
Increased anesthetic risk
What are the various anesthetic techniques that are sometimes used as alternatives to inhalation anesthesia in C-section patients?
Epidural anesthesia
Balanced anesthesia
Neuroleptanalgesia
Almost all anesthetic agents may cause this to the fetuses
Depression of respiration and/or circulation
What is a common complication of cesarean surgery?
Hemorrhage from the uterus
What are the reversal agents that can be used in the new born fetuses
Naloxone and Doxapram 1-2 drops delivered under the tongue or 0.1-0.2 ml injected into root of tongue
If bradycardia, can give 1 drop of dilute Atropine (0.25mg/ml) under the tongue or injected
If possible, this should be done to trauma patients before anesthesia
Should be stabilized and thoroughly evaluated
This problem is common in trauma patients
Respiratory difficulties
This may be present in the traumatized patient as a result of blood loss
Anemia
Animals with cardiovascular or respiratory disease may require special anesthetic techniques such as these
Preoxygenation and Manual control of ventilation
Why may prolonged recovery times be seen in hepatic or renal disease patients?
Hepatic or renal disease may delay excretion of injectable agents
What is the most common cardiovascular problem seen by the veterinary anesthetist?
Bradycardia
What are the anesthetic concerns for patients undergoing cesarean section?
Hypoxemia Hyperarbia Hypotension Bleeding Acid-base imbalance Tissue trauma Arrhythmias
Which is generally safer? The use of one or two drugs, or the use of multidrug protocols?
The use of multidrug protocols is generally safer than use of only one or two drugs.
These patients are perhaps the most challenging for the anesthetist
Patients with respiratory problems
Anesthesia should be delayed in respiratory disease patients until respiratory function has improved, but if surgery is absolutely required, this is preferable to general anesthesia
Local analgesia and gentle manual restraint
The use of these drugs should be avoided in patients with hepatic disease
Ketamine and Diazepam and
Barbiturate agents
Which are the drugs of choice for induction and maintenance of anesthesia on patients with hepatic disease?
Isoflurane or Propofol (require little or no hepatic function for elimination)
The organs most involved in maintains the volume and electrolyte composition of body fluids
Kidneys
Why is general anesthesia stressful for patients with renal disease?
General anesthesia decreases renal blood flow and renal function may be further compromised.
Emergency care is ideally a team effort involving…?
All hospital personnel
These things would be helpful to have in emergency care
Preauthorized emergency protocols
Periodic “dress rehearsals”
What can cause an animal to not stay anesthetized?
- Incorrect placement of Endotracheal tube
- Incorrect vaporizer setting
- Inadequate Endotracheal tube size
- Respirations too shallow?
- Oxygen flow rate adequate?
Excessive anesthetic depth may result from this
Excessive administration of anesthetic agents or from Preexisting patient problems
What is necessary to achieve a lighter plane of anesthesia in a patient who is too deeply anesthetized?
May be necessary to bag the patient with 100% oxygen to achieve a lighter plane of anesthesia
Pale mucous membranes may be the result of this
Anemia
Hemorrhage
Poor perfusion
Prolonged CRT suggests that this is presents
Hypotension
Shock if severe
A CRT greater than this suggests that blood pressure is inadequate to perfuse superficial tissues
Greater than 2 seconds
These drugs may also cause hypotension in susceptible patients
Acepromazine and the inhalation agents
These anesthetic agents can cause vasodilation and decrease blood pressure, resulting in poor perfusion of capillary beds and pale MM
Particularly inhalation agents, Propofol, and Acepromazine
Cyanosis is a critical emergency that arises because of this
Insufficient delivery of oxygen to the tissues
What can cyanosis result from?
- Machine problem
- Airway or Endotracheal tube blockage
- Respiratory difficulties from excessive depth
- Pneumothorax
- Respiratory disease
How is oxygen delivery to the patient reestablished?
Masking
Intubation
Tracheostomy
Abnormalities in cardiac rate and rhythm may result from this
Administration of anesthetic agents Electrolyte abnormalities Hypercapnia Hypoxia Many other factors
Tachycardia can result from the administration of these drugs
Atropine
Ketamine
Epinephrine
Tachycardia is present if the ❤rate is greater than this
>140 bpm Large Dog >160 bpm Small Dog >200 bpm Cat >60 bpm Horse >100 bpm Cow
Bradycardia may be secondary to the administration of these drugs
Alpha 2 agonists
Opioids
Bradycardia is present if❤rate is less than this
<40 bpm Cow
Respiratory arrest that is accompanied by cyanosis and/or bradycardia is considered this
AN EMERGENCY!!
Must be treated by ventilation with 100% oxygen
Cardiac arrests should be treated by the principles of this
ABCD (CBADE in PPT)
A- establish a patent airway
B- bag the patient with 100% O2
C- initiate internal or external cardiac massage
D- administer epinephrine and other drugs
Why is regurgitation and/or vomiting dangerous in the anesthetized animal?
Danger of airway obstruction and aspiration pneumonia
How can postanesthesia seizures be treated?
May be treated by eliminating external stimuli (light, sound, touch) and administering diazepam
(Sedate animal with Propofol if diazepam is unavailable)
Seizures in animals recovering from anesthesia can be caused by this
Administration of Ketamine
Diagnostic procedure: Myelography
Patient disorders: epilepsy or hypoglycemia
Opisthotonus
Stiff forelimbs
Dyspnea caused by laryngospasm or brachycephalic airway obstruction may be treated by ?
Treated by administration of oxygen by mask, reintubation of patient, or tracheostomy
Animals experiencing prolonged recovery from anesthesia require this
Close observation and nursing care
