Complications Flashcards
What is more likely the causative factor in cardiopulmonary arrest during spinal anesthesia?
Hypotension from spinal and sub-clinicacal respiratory depression with hypercarbia from sedation.
There are three areas of claims that are recently emerging, what are they?
Regional anesthesia-16%
Chronic pain management- 18%.
Acute pain-9%
Prevention of Ischemic Optic Neuropathy?
Enhance venous return by patient head up.
Minimize abdominal constriction.
Monitor BP carefully with A line.
Limit degree and duration of deliberate hypotension.
Avoid anemia.
Consider staging of long surgical procedures.
How much MAC is normally amnestic?
1/3 MAC
Why would Bicarb administration correct hyperkalemia?
When cells get acidotic, they push potassium into vascular. Giving NaHCO3 will get the potassium back into the cells.
What are signs and symptoms prior to arrest during spinal anesthesia?
Gradual decline in HR/BP.
Bradycardia.
Hypotension.
Cyanosis
What does histamine release from mast cells do to the blood capillaries?
Histamine increases the permeability and distention of blood capillaries.
Which type of allergic reaction is associated with atopy, urticaria, angioedema, and anaphylaxis.
Type I- immediate
How common is awareness under anesthesia?
0.1-0.4%, but explicit recall under GA is 0.013-0.023%
What are some pharmacologic prophylaxis measures that can be taken for known allergies to IV dye?
Pre-op admin of H1/H2 histamine antagonists, steroids.
Do ASA closed claims take into account all claims or only claims that had legal actions taken?
Only those that had legal actions taken
Current risk of death based on ASA 4 status?
5.5 in 10,000 incidence
What causes hearing loss after spinal anesthesia and how do you treat it
Due to CSF leak.
Blood patch=tx
Are there any temperature changes related to MH?
Yes; a late sign compared to other symptoms, but can increase core temp 1C every 5 minutes.
Which drugs are associated with MH?
Halogenated anesthetic gases and depolarizing muscle relaxants (Succinylcholine).
Why is calcium important in hyperkalemia?
Stabilizes the cardiac muscle. Doesn’t change the potassium level, but alters the resting membrane potential.
What is the most common equipment malfunctions leading to preventable anesthetic accidents?
Breathing circuit disconnects.
What happens 50% of the time after spinal anesthesia?
Hearing loss.
What is the reason for higher ION risk in CP bypass, abd/hip/neck procedures?
Low blood pressure
What is associated with Type III allergic reactions?
Immune Complex: Rheumatoid arthritis, serum sickness.
What is urticaria?
Hives; an outbreak of skin welts, bumps, or wheals.
What are symptoms of Ischemic Optic Neuropathy?
Range from decreased visual acuity to complete blindness.
Onset immediately to 12th post operative day.
What are 3 possible pathophysiological factors that cause MH?
Abnormal ryanodine receptors.
Abnormal secondary messengers and modulators of calcium release.
Abnormal sodium channel in skeletal muscle.
Define sentinel event:
An event in which a serious complication occurred.
Give 5 tx for hyperkalemia?
Beta 2 agonist like albuterol. NaHCO3. Insulin/dextrose. Hyperventilation. Calcium.
Tx for bronchospasm?
Deepen inhaled anesthetic.
Epi dilate bronchioles.
Positive pressure.
What symptoms related to hypermetabolism occur with MH?
Increased ETCO2. Increased O2 consumption. Low mixed venous O2 PP. Metabolic acidosis. Cyanosis. Mottling.
Which Local anesthetics have a higher rate of allergic reaction?
Ester type local anesthetics.
Which electrolyte abnormality poses a high potential for V-fib?
Hyperkalemia.
Treat with insulin and dextrose.
What are the Top 3 ASA Closed Claims?
- Death-26%
- Nerve Injury- 22%.
- Brain damage- 9%
What is the most common bust also transient eye injury?
Corneal abrasion.
What is the maximum occupational whole body exposure?
5rem/year
How common are anaphylactic reactions during anesthesia?
1:5,000 to 1:25,000
How long does it take for an anaphylactic reaction to show symptoms?
Within minutes of exposure to a specific antigen in sensitized individual.
What type of things are included in morbidity calculations?
Hoarseness, PONV, drug error, equipment malfunction without injury
What are muscle related signs of MH?
Masseter Spasm. Generalized rigidity. Elevated CK. hyperkalemia. Hypernatremia. Hyperphosphatemia. Myoglobinemia. Myoglobinuria.
How are anaphylactoid reactions different than anaphylaxis?
Resembles anaphylaxis, but does not depend on IgE antibody interaction with an antigen.
What is the most common cause of post operative loss of vision?
Ischemic Optic Neuropathy (ION).
What is atopy?
Refers to the genetic tendency to develop certain allergic diseases.
What arterial vessel branches from the internal carotid and supplies blood to the eye?
Opthalmic artery
Describe the steps in an anaphylactic reaction:
Antigen/allergen triggers production of IgE antibodies via B-Cells. IgE initially binds to the surface of the mast cell or basophil.
Subsequent exposure to the antigen will “bridge the gap between two IgE molecules which will cause degranulation of the Mast cell or basophil.
Degranulation causes histamine release.
What is the most common CV event after non-cardiac surgery?
MI
What four substances are mediators of anaphylaxis (what do mast cells release)?
- Histamine.
- Leukotrienes.
- BK-A.
- Platelet-activating factor
Which hypnotic agents have a relatively high prevalence of allergic reactions?
Pentothal 1:30,000.
Propofol 1:60,000.
What are examples of unpreventable anesthetic mishaps?
Sudden death syndrome.
Fatal idiosyncratic drug reactions.
Poor outcomes despite proper management.
Anesthesia awareness.
Why might an obstetric case have a higher risk of anesthesia awareness?
Versed is not used (to remember birth).
What are some of the largest reasons human error occurs in regards to death?
Fatigue. Production pressure. Long hours. Stress. Patient hand off
Does airway related mortality happen because of failure to intubate or failure to ventilate?
Failure to ventilate
Difficult ventilation 1.4-5%.
Difficult vent/intubation 0.4%.
CANNOT vent/intubate-0.008%
Current risk of death based on ASA 1 status?
0.5 in 10,000 incidence
What are risk factors for anesthesia awareness?
Female. Younger age. Obesity. Clinician inexperience. Previous awareness. Emergency procedures. Use of non-depolarizing relaxants.
What are some signs and symptoms of anaphylaxis?
Acute respiratory distress, circulatory shock, death (from asphyxiation or irreversible circulatory shock).
Mechanism of action of Dantrolene?
Directly interferes with muscle contraction by binding Ryr1 receptor, calcium channel and inhibiting calcium ion release from sarcoplasmic reticulum.
New data implicates anesthetic agents with developmental delays, but what is likely about this data?
There are more concurrent issues than simply anesthetic agents being used. Mulitple surgeries with multiple hours of anesthesia.
What is the typical effect of leukotrienes/histamines/bradykinin on the lungs during a reaction?
Typical asthma response: Constriction of bronchioles and airway obstruction from mucous buildup.
Why is increased capillary permeability a concern with anaphylactic reactions?
Can lose up to 50% of intravascular volume from capillary leak.
What is the greatest complication after dantrolene use?
Muscle weakness- respiratory insufficiency and risk for aspiration.
What is the most common airway injury (not sued for)?
Sore throat
What are risk factors associated with hypersensitivity to anesthetics?
Female gender (d/t cosmetic use).
Atopic history.
Preexisting allergies.
Previous anesthesia exposure.
What large artery supplies blood to the eye?
Internal carotid
What vocal cord related issue is related to long intubations and multiple intubations?
Vocal cord granuloma
How are the symptoms different between anaphylaxis and anaphylactoid reactions?
Clinically indistinguishable and just as life threatening.
What are the three major goals of the ASA Closed Claims Project?
- Identify major areas of loss in anesthesia ($$),
- Identify patterns of injury,
- Identify strategies for prevention.
What is an example of an H1 histamine blocker?
diphenhydramine.
Tx protocol for MH:
D/C drugs. Call for help. 100% FiO2. NaHCO3. Dantrolene (ryanodex). Cooling measures. Inotropes/antiarrythmic agents. Additional dantrolene.
What are other uses for dantolene?
Hyperthermia associated with thyroid storm.
Neurolept malignant sydrome.
Treatment of chronic spastic disorders.
What are current anesthesia related death rates?
1 per 100,000 anesthetics
What substance is shared between esters that likely facilitates allergic reactions?
PABA
Which type of allergic reaction is associated with contact dermatitis like poison ivy/oak/latex?
Type IV- delayed, cell mediated
What is one of the largest preventable anesthetic issues relating to human error?
Alarm fatigue
What anesthetic medication has the highest incidence of allergic reaction?
#1 Rocuronium #2 Succinylcholine. #3 Atracurium.
In the OR, who typically controls the ignition source? Fuel source? Oxidizing agent?
Fuel source=surgical Nurses.
Oxidizing agents=anesthesia.
Ignition source=surgeons.
What is the current rate of Minor incidence morbidity?
18-22%
How often is human error implicated in deaths?
51-77%
What is the most sensitive AND specific indicator/sign of MH?
Increased ETCO2. Some books say tachycardia is first sign.
What are typical effects of leukotrienes/histamines/etc on blood vessels?
Dilated blood vessels.
What are food allergies that are cross reactions with latex?
Mango, kiwi, chestnut, avocado, passion fruit, banana
Define critical event:
An event in which a complication occurred or had potential to occur.
Since the 1980s, how has anesthesia related mortality changed?
10 fold decrease since 1980s
After NMBAs, what is the next most common allergic reaction?
Latex allergy
What causes ION?
Optic nerve infarction due to decreased oxygen delivery via one or more arterioles supplying the optic nerve.
Radiation exposure can be limited by what?
Lead aprons.
Thyroid shields.
>6ft away.
Lead glass partitions.
What is Malignant hyperthermia?
A rare myopathy, characterized by an acute hypermetabolic state in muscles tissue after induction of GA.
What are the four types of allergic-hypersensitivity reactions?
- Type I Immediate
- Type II- Cytotoxic.
- Type III- Immune Complex.
- Type IV-Delayed, cell-mediated.
Treatment of anaphylactic and anaphylactoid reactions?
D/C drug administration. Administer 100% oxygen. Epi (0.01-0.05mg). Consider ETT. IV fluids 1-2 L. H1 and H2 histamine blocker. Steroids.
What puts patients at the highest risk for anesthesia awareness?
Major trauma (43%).
What is an example of an H2 histamine blocker?
Ranitidine.
What is the most common airway injury we get sued for?
Dental injury
Describe the amnestic effects of benzodiazepines?
Anterograde- from the moment the medication is administered.
What are examples of preventable anesthetic mishaps?
Human error.
Equipment malfunction
Describe the amnestic effects of scopolamine?
Retrograde- Can be even before the medication was given.
What are treatment measures for cardiopulmonary arrest from spinal anesthesia?
Ventilatory support.
Ephedrine/atropine/epinephrine.
CPR.
Which patients are are especially high risk for ION?
CP bypass.
Radical neck dissection.
Abd and hip procedures. Prone positioned procedures.
How is calcium related to MH?
Sarcoplasmic reticulum stops reuptaking Calcium which causes muscles contraction without relaxation.
What are the limits of acceptable trace concentrations of anesthetic gases?
N2O <25ppm.
N2O and Halogenated <25ppm and <0.5.
Halogenated only <2ppm
After general anesthesia, what are some factors that may cause hearing loss?
Surgical manipulation. Middle ear barotrauma. Vascular injury. Ototoxicity of drugs. S/P CP bypass
What is typically “worse”, bronchospasm or laryngospasm?
Bronchospasm.
What pathological processes are associated with Type II allergic reactions?
Type II=Cytotoxic.
- Hemolytic transfusion reactions.
- Autoimmune hemolytic anemia.
- Heparin-induced thrombocytopenia.
