**6.4 Follow up**

*Clinical Management of Shock - The Science and Art of Physiological Restoration*

administered in patients with history of heart disease [93].

cells and basophils, via increased cAMP production [94].

mias and myocardial infarctions [97].

ventricle syndrome and PEA [98].

offers some basis for their use [90].

**6.3 Additional consideration**

**6.2 Adjunct treatments**

patients with heart failure to prevent fluid overload.

epinephrine in anaphylaxis is infrequent and often delayed [80]. There are no contraindications for use of epinephrine in anaphylaxis, and it should still be

Epinephrine exerts its effects via alpha and beta adrenergic receptors in a dosedependent response where beta receptors effects are dominant at low doses, but alpha receptors effects are seen at higher doses. The α1 receptors cause vasoconstriction increasing peripheral vascular resistance and blood pressure and improving coronary and cerebral perfusion. The β1 receptors exert positive chronotropic and inotropic effects which improves cardiac output and increases blood pressure. In the respiratory system, β2 receptors stimulation results in bronchodilation, and relief and respiratory symptoms. β receptors also inhibit release of mediators from mast

In most situations intramuscular administration is preferred, but IV epinephrine can be used in the ICU. IM epinephrine should be given in 0.2–0.5 mg doses (1:1000 dilution), and repeated every 5 min depending on the resolution of symptoms [86]. Studies showed that peak epinephrine concentrations were higher when epinephrine was given IM into the thigh, compared to IM administration in the arm or subcutaneous administration [95]. Multiple doses of epinephrine may be required to reverse symptoms [96]. Care should be taken to closely monitor pulse and blood pressure when epinephrine is administered intravenously as there is greater risk of severe adverse effects compared to intramuscular administration including arrhyth-

Following epinephrine administration, patients should continue to be assessed for worsening signs of anaphylaxis. Patients should be placed on pulse oximeter and given high flow oxygen as needed. Patients in anaphylactic shock should be placed in supine or Trendelenburg position to increase blood return to the heart. Patients who are sitting upright can have a significant decrease in preload leading to empty

Due to the intravascular depletion, fluid is often necessary to maintain pressure. Crystalloids or colloids may be used, although physicians should be aware of the anaphylactic potential of some colloid solutions. Normal saline (0.9% saline) should be chosen over other crystalloids as it remains in the intravascular space longer than dextrose solutions [86, 99]. Caution should taken while giving fluids to

Antihistamines are often given as adjunct therapy in anaphylaxis, however there is no evidence to support or advise against their use in anaphylaxis [100]. Steroids may be used to prevent biphasic anaphylaxis [86], although there is no evidence to

Nebulized albuterol or other beta-2 agonists may be useful to treat respiratory distress due to bronchoconstriction. While there is no clinical trial on use of these medications in anaphylaxis, their effectiveness in treating other allergic diseases

Beta blockers may complicate the treatment of anaphylaxis, as some of the beneficial effects of epinephrine will be diminished [103]. In patients on betablockers who do not respond to epinephrine and fluids, other vasopressors should be considered. Glucagon has been reported to be a successful treatment in several case reports of patients on beta blockers who experienced anaphylactic shock [104].

support the use of steroids in acute treatment of anaphylaxis [101, 102].

**86**

Before discharging a patient that experienced anaphylaxis, they should be referred to an immunologist for a thorough evaluation. Labs to assess for anaphylaxis (i.e. tryptase, histamine) should be drawn to assist allergist in making a diagnosis. Patients should also receive a prescription for an epinephrine autoinjector, along with education on how to use it [87].
