Mod12: Treatment of Anaphylaxis DuringAnesthesia Flashcards
Treatment of Anaphylaxis During Anesthesia
What does Primary treatment starts with?
Stop antigen administration
Treatment of Anaphylaxis During Anesthesia - Primary treatment
After stopping administration of the antigen, what must you do next in a patient with no advanced airway?
Maintain airway via preemptive instrumentation, and
Administer 100% oxygen to correct V/Q mismatch if suspected and prevent ischemia
Treatment of Anaphylaxis During Anesthesia - Primary treatment
True or False: during an anaphylaxis, it is appropriate to discontinue all anesthetic agents and wake the pt up if the surgical procedure allows it.
True
If the surgical procedure does not allow it, communicate with the surgeon to possibly shorten the procedure and complete it at a later time
Treatment of Anaphylaxis During Anesthesia - Primary treatment
Why would you consider additional IV access and arterial line as part of the primary treatment of anaphylaxis?
Volume expansion for hypotension
Strict BP monitoring
Treatment of Anaphylaxis During Anesthesia - Primary treatment
What’s the first Tx for hypontension during anaplylaxis?
Volume expansion
Treatment of Anaphylaxis During Anesthesia - Primary treatment
Why is volume expansion the first Tx for hypontension during anaplylaxis?
Up to 40 percent loss of intravascular fluid into the interstitial space d/t increased capillary permeability
Treatment of Anaphylaxis During Anesthesia - Primary treatment
Which solutions would you use for volume expansion in the Tx of hypontension during anaplylaxis?
25-50 ml/kg of
Lactated Ringer’s solution - Normal saline
(75% will move into the intertitial space after 30 min),
or
Colloid solutions
(beneficial d/t higher oncotic pressure)
Treatment of Anaphylaxis During Anesthesia - Primary treatment
How would you treat persistent hypotension resistant to initial volume expansion during anaphylaxis?
Additional volume
Treatment of Anaphylaxis During Anesthesia - Primary treatment
What are the three different ways Epinephrine is helpful in the Tx of anaphylaxis?
Inhibits mediator (histamine) release by increasing cyclic AMP in mast cells and basophils
(This stabilizes the cells and prevents degranulation)
Alpha1 effects to reverse hypotension
Beta2 effects for bronchodilation
Treatment of Anaphylaxis During Anesthesia - Primary treatment
A benefit of Epinephrine is that it has a rapid onset when given IV, but why are repeated doses necessary?
It has short duration
Treatment of Anaphylaxis During Anesthesia - Primary treatment
How much Epi would you give to treat hypotension a/w anaphylaxis?
5 - 10 mcg IV
Titrated doses for hypotension
Treatment of Anaphylaxis During Anesthesia - Primary treatment
How much Epi should you give to treat cardiovascular collapse a/w anaphylaxis?
0.1 - 1mg IV
Titrated doses for cardiovascular collapse
(Higher doses may be required for CV collapse - May also consider a continuous infusion)
Treatment of Anaphylaxis During Anesthesia - Primary treatment
Epinephrine is available in a very concentrated form. What is crucial that you do properly prior to administration?
Dilute it down appropriately to avoid administration of a massive dose
Treatment of Anaphylaxis During Anesthesia - Primary treatment
How could you administer Epi to treat anaphylaxis in patients with laryngeal edema without hypotension?
Subcutaneous
Treatment of Anaphylaxis During Anesthesia - Hypersensitive to Epinephrine
Patients taking which drugs may be hypersensitive to Epinephrine?
Tricyclic antidepressants
MAO inhibitors
Cocaine or other stimulants
(Concomitant administration of Epi to these pts may exhacerbate tachycardia and result in cardiac ischemia)
Treatment of Anaphylaxis During Anesthesia - Secondary Treatment
How much of which H1 receptor antagonist drug should you administer as secondary treatment in the Tx of anaphylaxis?
Benadryl 25 to 50 mg IV (up to 1.0 mg/kg)
Treatment of Anaphylaxis During Anesthesia - Secondary Treatment
How does Benadryl attenuate systemic effects in chemically mediated reactions responsible for anaphylaxis?
Via H1 and H2 receptors antagonism
Treatment of Anaphylaxis During Anesthesia - Secondary Treatment
True or False: Antihistamines inhibit histamine release
False
Antihistamines compete with histamine at receptor sites but do not inhibit histamine release
Treatment of Anaphylaxis During Anesthesia - Secondary Treatment
True or False: Benadryl (diphenhydramine), an H1 antagonist, blocks both H1 and H2 receptors
False
H1 antagonists do not block H2 receptors
Treatment of Anaphylaxis During Anesthesia - Secondary Treatment
True or False: Tagamet (cimetidine), Zantac (ranitidine), and Pepcid (famotidine), H2 antagonists, blocks both H1 and H2 receptors
False
H2 antagonists do not block H1 receptors
Treatment of Anaphylaxis During Anesthesia - Secondary Treatment
What are recommended doses for H2 antagonits?
Tagamet (cimetidine) 400 mg IV
Zantac (ranitidine) 150 mg IV
Pepcid (famotidine) 20 mg IV**
(** most commnonly given in the OR)
Treatment of Anaphylaxis During Anesthesia - Secondary Treatment
Why are Corticosteroids (0.25-1.0g hydrocortisone) beneficial in the Tx of anaphylaxis?
May alter the activation of other inflammatory cells following an acute reaction
Treatment of Anaphylaxis During Anesthesia - Secondary Treatment
Corticosteroids onset is 12 to 24 hours later. Why give then during an acute reaction?
May attenuate recurring or late-phase reactions
Useful in refractory bronchospasm or shock
Treatment of Anaphylaxis During Anesthesia - Secondary Treatment
Which corticosteroid is particularly useful in protamine reactions?
1 to 2 g of methylprednisolone (30 to 35 mg/kg)
Treatment of Anaphylaxis During Anesthesia - Secondary Treatment
Which drug will you administer to treat Bronchospasm refractory to epinephrine?
Inhaled ß2-adrenergic agents
(albuterol or terbutaline)
Treatment of Anaphylaxis During Anesthesia - Secondary Treatment
How much and via which route will you administer inhaled ß2-adrenergic agents (albuterol or terbutaline) to treat Bronchospasm refractory to epinephrine?
4 to 12 metered dose inhaler puffs via ETT
Give at inspiration
Effectiveness manifest as drop in peak airway pressure
and increased tV
Repeat if not improving or wrsening PIP and tV
Treatment of Anaphylaxis During Anesthesia - Secondary Treatment
How much of nebulized albuterol will you administer to treat Bronchospasm refractory to epinephrine?
0.25 to 1mL of albuterol in 2.5mL of normal saline
Treatment of Anaphylaxis During Anesthesia - Catecholamine infusions
When would consider a Catecholamine infusion?
Persistent hypotension or bronchospasm
Treatment of Anaphylaxis During Anesthesia - Catecholamine infusions
At what rate would you administer an Epinephrine infusion?
4-8 mcg/min
Treatment of Anaphylaxis During Anesthesia - Catecholamine infusions
At what rate would you administer an Norepinephrine infusion?
4-8 mcg/min
Treatment of Anaphylaxis During Anesthesia - Catecholamine infusions
When is Norepinephrine infusion indicated?
Norepinephrine decreases cyclic AMP
Use only in patients with refractory hypotension due to decreased systemic vascular resistance
Treatment of Anaphylaxis During Anesthesia - Catecholamine infusions
Which Catecholamine infusion is indicated when ß1, ß2 selective properties that produce tachy dysrhythmias* (sometimes needed in EP to localize and ablate dysrhythmias) and systemic vasodilatation are needed?
Isoproterenol 0.5-1.0 mcg/min
Treatment of Anaphylaxis During Anesthesia - Catecholamine infusions
In which conditions is Isoproterenol indicated?
Used in patients with:
Refractory bronchospasm
Pulmonary hypertension or
Right ventricular dysfunction
Treatment of Anaphylaxis During Anesthesia - Catecholamine infusions
Why should Isoproterenol be used cautiously in hypotensive or hypovolemic patients?
Profound ß2 effects can produce systemic vasodilatation
Treatment of Anaphylaxis During Anesthesia - Catecholamine infusions
Depending on treatment objectives, which other Catecholamine infusions could be used in the Tx of anaphylaxis?
Dopamine 3-20 mcg/kg/min
Dobutamine 5-20 mcg/kg/min
Treatment of Anaphylaxis During Anesthesia - Secondary Treatment
What are appropriate interventions to increase the effectiveness of Epinephrine in the context of refractory hypotension or acidemia?
Monitor ABGs
Treat acidemia with Sodium bicarbonate 0.5 to 1 mEq/kg
Reduced acidemia improves effectiveness of Epi
Treatment of Anaphylaxis During Anesthesia - Secondary Treatment
When would you use Phosphodiesterase Inhibitors to treat bronchospasm?
In refractory bronchospasm, not aleviated by drugs used for primary treatment and hemodynamic stability
Treatment of Anaphylaxis During Anesthesia - Secondary Treatment
Which Phosphodiesterase Inhibitor would you use to treat refractory bronchospasm during anaphylaxis? and how much?
Aminophylline
Loading dose of 5 to 6 mg/kg given over 20 minutes
Followed by an infusion of 0.5-0.9 mg/kg/hr
Tx of Anaphylaxis - Refractory cases not responding to Epi and volume
Which pressor would be indicated for the Tx of hypotension that is refractory to epinephrine and volume replacement?
Vasopressin 2 – 5 units
Tx of Anaphylaxis - Refractory cases not responding to Epi and volume
Pts taking which drugs chronically are at risk for hypotension that is refractory to epinephrine and volume replacement?
Patients on alpha or beta blockers
Tx of Anaphylaxis - Refractory cases not responding to Epi and volume
What are the beneficial effects of Glucagon (1 mg IV) in the treament of hypotension that is refractory to epinephrine and volume replacement?
Polypeptide hormone with
potent chronotropic and inotropic effects
(increases cAMP)
Tx of Anaphylaxis - Refractory cases not responding to Epi and volume
If required, what would be the rate of Glucagon continuous infusion?
1 to 5 mg/hr
Tx of Anaphylaxis - Refractory cases not responding to Epi and volume
Which lab value should be monitored during a Glucagon continuous infusion?
Blood glucose
To prevent Hyperglycemia
Tx of Anaphylaxis - Refractory cases not responding to Epi and volume
Which drug is inticated in the Tx of refractory hypotension not responding to Epi and volume in patients receiving ACE inhibitors chronically?
Angiotensinamide
Treatment of Anaphylaxis During Anesthesia
What should you consider before removing an ETT from these pts?
Evaluation of airway
Extent of laryngeal edema
Treatment of Anaphylaxis During Anesthesia
How would you manage a pt with persistent facial edema after an anaphylactic reaction?
Delay extubation
May continue for 24 hours
(Keep intubated for at least 24hrs)
Treatment of Anaphylaxis During Anesthesia
How would you evaluate extent of airway edema prior to extubation?
Persistent facial edema suggests airway edema
Deflate ET tube cuff and listen for leak around it. Ensure there is a significant air leak after endotracheal tube cuff deflation before extubation
Direct laryngoscopy may be performed before extubation of the trachea to visually inspect laryngeal structures
(This is not common practice!!!)
Treatment of Anaphylaxis During Anesthesia
Why is Direct laryngoscopy not common practice when laryngeal edema is suspected following an anaphylactic reaction?
it requires resedating and reparalyzing the pt
Treatment of Anaphylaxis During Anesthesia
What should you do next if you have strong suspicion of laryngeal edema as evidenced by facial edema and absence of leak around deflated ET tube cuff?
A. Perform a DL to visually inspect laryngeal structure
B. Transfer the patient to the ICU for 24 hr monitoring
A. Perform a DL to visually inspect laryngeal structure
B. Transfer the patient to the ICU for 24 hr monitoring
Treatment of Anaphylaxis During Anesthesia - Pts under general anesthesia
Why are sympathetic responses altered during anaphylaxis for patients under general anesthesia?
Inhalational anesthetics
Treatment of Anaphylaxis During Anesthesia - Pts under general anesthesia
How do inhalational anesthetics alter sympathetic responses during anaphylaxis in patients under general anesthesia?
Interfere with compensatory response to shock and cardiovascular dysfunction
Treatment of Anaphylaxis During Anesthesia - Pts under general anesthesia
Why are inhalation anesthetics not the bronchodilators of choice in treating bronchospasm following anaphylaxis, especially during hypotension
Because of the significant hypotension in anaphylaxis
Treatment of Anaphylaxis During Anesthesia
Why would Patients under spinal or epidural anesthesia require a larger dose of catecholamine during anaphylaxis?
Because they have already received a partial sympathectomy via spinal or epidural anesthesia
Treatment of Anaphylaxis During Anesthesia
Why is early recognition and early treatment with administration of medications of the utmost importance in anaphylaxis?
Patients who do not appear to have life threatening symptoms on initial presentation may progress to life threatening anaphylaxis
Early recognition of anaphylaxis has a huge effect on mortality and morbidity
The transition from initial minor symptoms to life-threatening symptoms can happen rather quickly
Treatment of Anaphylaxis During Anesthesia
Most drugs used to treat the acute symptoms of anaphylaxis are short-acting. Why would you consider adding longer-acting drugs after resolution of the initial treatment phase?
Because of the risk of Biphasic anaphylaxis
Some patients have a late or second phase of anaphylaxis, even after complete resolution of the first response
This is why patients who receive epinephrine for the treatment of anaphylaxis may not improve sufficiently or may improve and then relapse
Consider longer-acting drugs such as:
Hydrocortisone 250 mg IV (prevents delayed release of inflammatory compounds - does not produce an immediate effect)
Treatment of Anaphylaxis During Anesthesia
What could you do to guard againts Biphasic anaphylaxis?
Supplement emergency short acting drugs with
Continuous infusions, or
Longer acting drugs (???)
Treatment of Anaphylaxis During Anesthesia - Being prepared
How could you prepare and guard againts anaphylaxis?
Identify those at risk
Training in recognition
(make it part of your differential diagnosis)
Be familiar with Posters in operating room
(May provide guidelines in treatment, and guidelines for investigation)
Drugs for the immediate treatment of an anaphylactic reaction should always easily be available
(Epi must always be present in the anesthesia cart, and you must know how to dilute it down)
Kits for blood sampling must be readily available
Treatment of Anaphylaxis During Anesthesia - Informing the patient
Why should you inform a patient that had recovered from anaphylaxis about what happened?
So that they aware of which drug or substance they are allergic to, along with the associated allergic response
Treatment of Anaphylaxis During Anesthesia
How and when should you document an anaphylactic reaction
Document details in anesthetic record
As soon as possible
Treatment of Anaphylaxis During Anesthesia
Why should the patient be referred to an allergist familiar with testing for anesthesia agents
So they can be tested for other allergens
Treatment of Anaphylaxis During Anesthesia
Why must the patient be encouraged to carry an allergy card?
To be shown for any subsequent anesthesia exposure and
Prevent re-exposure
Treatment of Anaphylaxis During Anesthesia
How long must causative agents and drugs that cross react with a known allergen that had caused anaphylaxis be eliminated for the patient and become part of his/her permanent medical record?
For life!!!
Treatment of Intraoperative Anaphylaxis
What are steps in the treatment of an anaphylactic reaction?
Discontinue the offending agent
Airway support: Increase FiO2 and provide airway support
Epinephrine: Start with 5-10 mcg IV for hypotension and 0.1-1 mg IV for CV collapse
Liberal IV hydration: Crystalloid 10- 25 mL/kg or colloid 10 ml/kg (repeat if necessary)
H1-receptor antagonist: Diphenhydramine 0.5-1.0 mg/kg IV
H2-receptor antagonist: Ranitidine 50 mg IV or famotidine 20 mg IV
Hydrocortisone 250 mg IV (prevents delayed release of inflammatory compounds - does not produce an immediate effect)
Albuterol for bronchospasm
Vasopressin for refractory hypotension. Start at 0.01 unit/min
