Advanced Anesthesia Monitoring

What are the mortality rates associated with anesthesia in healthy animals vs animals w/ preexisting disease?

Healthy animals: less than 1%, animals with preexisting disease: 1-4%

Which two body systems are most commonly associated with anesthetic deaths?

Cardiovascular and respiratory systems

During which stages of anesthesia do most anesthetic complications occur?

Anesthetic maintenance and postoperative recovery

What are the major causes of human error during anesthesia?

Inadequate training, unfamiliarity with equipment or drugs, poor patient preparation, drug errors, fatigue, and inattention

What drug administration errors can occur during anesthesia?

Math errors, failure to weight the patient appropriately, wrong medication used, wrong concentration used, incorrect route, and confusion between syringes

What equipment-related problems can cause anesthetic complications?

Not turned on or full oxygen supply, exhausted soda lime, blocked or misplaced ETT, vaporizer problems, and closed pop-off valve

What patients are considered high risk?

Neonates, geriatrics, brachycephalic dogs, sighthounds, and obese animals

What complications are neonates at increased risk for during anesthesia?

Hypothermia, dehydration, overhydration, hypoxemia, hypotension, hypoventilation, and hypoglycemia

What cardiac abnormality should be closely monitored in neonates?

Bradycardia

Why should heat loss be minimized in neonatal patients?

Neonates are particularly susceptible to hypothermia

Why should prolonged fasting be avoided in neonates?

Increased risk of hypoglycemia

What IV fluid supplementation mat be considered for neonates?

5% dextrose in isotonic crystalloids administered with an infusion pump

What adjustments should be made to injectable anesthetic drugs in neonates?

Reduce doses and dilute injectable medications if necessary

What type of anesthetic agents are preferred for neonates?

Inhalant agents over injectable agents

Why should dead space be minimized in neonatal anesthesia?

To reduce rebreathing of exhaled gases and support adequate ventilation

Why are geriatric patients at increased anesthetic risk?

Reduced organ function, poor stress tolerance, and increased susceptibility to hypothermia, hypotension, respiratory depression, and overhydration

By how much should anesthetic diseases be reduced in geriatric patients?

30-50%

Why should geriatric patients be given more time to respond to anesthetic drugs?

They may have delayed responses due to reduced organ function

How should IV fluid administration be adjusted in geriatric patients?

Administer fluids at reduced rates

How should should geriatric patients be preoxygenated?

At least 3 minutes

What anesthetic drugs are preferred in geriatric patients?

Short-acting and reversible drugs

How can analgesia and local/regional nerve blocks benefit geriatric patients?

They reduce the amount of general anesthetic required

What preexisting diseases should be considered when evaluating geriatric patients?

Hyperadrenocorticism, diabetes mellitus, and hypothyroidism

What precautions are important during geriatric anesthetic recovery?

Maintain warmth, monitor for hypoxemia and aspiration pneumonia, and keep the patient sternal when appropriate

Why should premedications be considered in geriatric patients?

They help reduce the amount of general anesthetic required and minimize adverse effects

Why can anesthetic drug dosing be difficult in obese patients?

They have a higher percentage of body fat, which has relatively low blood supply

What respiratory pattern is commonly observed in obese anesthetized patients?

Rapid, shallow respirations

How long should obese patients be preoxygenated?

5 mins before induction

What precautions are recommended for obese patients during induction?

Preoxygenate and induce rapidly

When might obese patients require assisted ventilation?

When ventilation is inadequate or rapid, shallow breathing causes respiratory complications

What anatomical abnormalities contributes to BOAS?

Stenotic nares, elongated soft palate, everted laryngeal saccules, and small diameter trachea

Why are brachycephalic patients prone to bradycardia?

Increased parasympathetic tone

What medication is recommended before intubating brachycephalic patients?

Atropine

What precautions should be taken when preoxygenating brachycephalic patients?

Avoid placing excessive mask pressure on the eyes

Why may brachycephalic patients require a smaller ETT?

Their trachea may be smaller than expected for their body size

What precautions should be taken during brachycephalic induction?

Preoxygenate, induce rapidly with IV agents, and intubate quickly and efficiently

Why should head and neck manipulation be minimized in brachycephalic patients?

To reduce the risk of airway obstruction

What emergency supplies should be available during brachycephalic recovery?

Propofol, ETT, and oxygen for emergency reintubation

Why should stress and excitement be minimized during brachycephalic recovery?

To reduce hyperventilation and respiratory distress

What medication class may help minimize airway swelling in brachycephalic patients?

Steroids

What anesthetic drug class are sighthounds historically sensitive to?

Thiobarbiturates

What alternative anesthetic agents are listed for sighthounds?

Propofol, midazolam, diazepam with ketamine, and alfaxalone

Why are patients with cardiovascular disease at increased anesthetic risk?

Compromised circulation and increased susceptibility to cardiac complications

What complications are common in cardiac patients during anesthesia?

Pulmonary edema, arrhythmias, tachycardia, and overhydration

What diagnostics may be performed before anesthetizing cardiac patients?

Bloodwork, thoracic radiographs, ECG, and cardiac ultrasound

Why should stress and restraint be minimized in cardiac patients?

To prevent increased cardiac workload

What anesthetic agents should be avoided in cardiac patients?

Agents that depress myocardial contractility, increase cardiac workload, or cause arrhythmias

Why must fluid administration be carefully monitored in cardiac patients?

They are susceptible to overhydration and pulmonary edema

What intraoperative fluid rate is recommended for cardiac patients?

1-3 ml/kg/hr

What anesthetic complications can worsen cardiac dysfunction?

Hypoxemia, hypercapnia, hypothermia, and vagal stimulation

What should be done if a cardiac patient is dehydrated or hypovolemic before anesthesia?

Correct fluid deficits with appropriate fluid therapy while avoiding overload

Why are patients with respiratory disease at increased anesthetic risk?

They may have impaired tissue oxygenation and respiratory distress

What diagnostics are recommended before anesthetizing respiratory patients?

Physical examination, bloodwork, thoracic radiographs, blood gas analysis, and electrolytes

What anesthetic drugs should be avoided in respiratory patients?

Drugs that cause respiratory depression or upper airway muscle relaxation

What induction method is recommended for respiratory patients?

Injectable induction followed by rapid intubation

What emergency airway procedure should personnel be prepared to perform with respiratory patients?

Tracheostomy

What monitoring parameters are especially important in respiratory patients?

Spo2 and end tidal co2 (etco2)

What postoperative care may respiratory patients require?

Airway suctioning, oxygen therapy, and close respiratory monitoring

Why does hepatic disease increase anesthetic risk?

Impaired drug metabolism, decreased clotting factor synthesis, and altered protein/carbohydrate metabolism

Why may hepatic patients experience prolonged anesthetic recovery?

Delayed metabolism of anesthetic drugs

What clinical abnormalities may occur in hepatic patients?

Dehydration, anemia, icterus, hypoproteinemia, hypoglycemia, and hepatic encephalopathy

Why are hepatic patients at increased risk of bleeding?

Decreased synthesis of blood clotting factors

Why is blood glucose monitoring important in hepatic patients?

They may develop hypoglycemia due to impaired carbohydrate metabolism

What premedications are recommended to avoid in hepatic patients?

Acepromazine and benzodiazepines

What anesthetic agents are preferred in hepatic patients?

Isoflurane and sevoflurane

What drug characteristics are preferred in hepatic patients?

Short acting, reversible drugs requiring minimal hepatic metabolism

What should guide anesthetic drug selection for hepatic patients?

Preanesthetic bloodwork and diagnostic results

What electrolyte and acid-base abnormalities are common in renal patients?

Hyperkalemia and metabolic acidosis

Why does renal disease increase anesthetic risk?

Delayed drug excretion and reduced renal perfusion during anesthesia

What bloodwork is important before anesthetizing renal patients?

BUN, creatinine, SDMA, and electrolytes

Why should dehydration be corrected before anesthetizing renal patients?

To maintain renal perfusion and reduce further kidney damage

Why. should prolonged water restriction be avoided in renal patients?

It can worsen dehydration and compromise renal perfusion

Why should injectable NSAIDs be used cautiously in renal patients?

They may reduce renal perfusion

What blood pressure targets are recommended for renal patients?

MAP: above 60-70 mmHg, systolic BP: above 80-90 mmHg

Why must hypotension be corrected promptly in renal patients?

Low blood pressure decreases renal perfusion and may worsen kidney dysfunction

What anesthetic drug adjustments may be necessary in renal patients?

Reduced anesthetic doses due to delayed drug excretion

What recovery complication may occur in renal patients?

Prolonged anesthetic recovery

What anesthetic risks are increased in the dam during cesarean section?

Increased cardiac workload, respiratory compromise, vomiting/regurgitation, hypotension, and hemorrhage

Why are offspring at risk during cesarean section anesthesia?

Anesthetic agents cross the placenta and may cause respiratory and cardiovascular depression

What respiratory complications may occur in c-section offspring exposed to anesthetic agents?

Hypoxemia and hypercapnia

What preparations should be completed before inducing anesthesia for cesarean section?

Establish IV access, clip and prep the patient, administer IV fluids, and preoxygenate

What anesthetic precautions are recommended for c-section dams?

Use the lowest effective general anesthetic dose, induce IV, and intubate quickly

What regional anesthetic technique may be considered for cesarean section?

Epidural analgesia combined with neuroleptanalgesia

What complication should be monitored during the recovery of a c-section dam?

Vomiting or regurgitation

How should a c-section offspring’s airway be cleared after delivery?

Using a bulb syringe

What treatments may be used to support newborn offspring after cesarean section?

Oxygen by face mask, reversal agents as indicated, and atropine for bradycardia

What complications make trauma patients high-risk anesthetic candidates?

Respiratory distress, cardiac arrhythmias, shock, hemorrhage, and internal injuries

How long after trauma may cardiac arrhythmias occur?

Up to 72 hours

What respiratory injuries may occur in trauma patients?

Pneumothorax, pulmonary contusions, hemorrhage, and diaphragmatic hernia

How can respiratory injuries affect cardiovascular function?

Decreased oxygen exchange can cause myocardial hypoxia

What complications can result from myocardial hypoxia?

Arrhythmias, acid-base imbalances, and cellular damage

How can blood loss affect trauma patients?

Hypotension and anemia

What diagnostics are recommended before anesthetizing trauma patients?

Thorough physical examination, thoracic radiographs, and ECG

What should be done before anesthesia in trauma patients whenever possible?

Stabilize the patient and preoxygenate

What is the appropriate initial response to an anesthetic emergency?

Assess the patient, identify priorities, consult the DVM, and initiate appropriate interventions

What emergency supplies should every clinic have readily available?

A crash cart containing emergency drugs and supplies, plus a visible emergency drug dosage chart

Why should an anesthetic emergency be reviewed afterward?

To identify the cause and prevent similar emergencies

What are common anesthetic emergencies?

Patient too light or too deeply anesthetized, pale MM, prolonged CRT/hypotension, dyspnea/cyanosis/tachypnea, abnormal HR/rhythm, apnea, respiratory arrest, cardiac arrest

What vaporizer problems may prevent a patient from staying anesthetized?

Low setting, insufficient anesthetic liquid, malfunction, or incorrect calibration

What ETT problems may prevent adequate anesthesia?

Blocked, misplaced, disconnected, too small, or inadequately cuffed ETT