Prevention and Treatment of Anaphylactic Reactions

Medical prevention of anaphylaxis is useful in avoiding reactions to iodinated radiographic contrast media. It is recommended in patients with a high risk for ana-phylactic/anaphylactoid reaction to CM as defined earlier (Sect. 4.4). Premedication has not been proven to have any benefit in all other perioperative anaphylac-tic/anaphylactoid reactions, e.g., reactions to latex or muscle relaxants.

The treatment of anaphylaxis is based on a few very important factors (for details, see Table 4.4).

Supine position, elevated legs

• Volume substitution

- Crystalloids (saline or ringer solution) 30 ml/kg i.v.

Grade Type of reaction

Dermatological Respiratory tract Cardiovascular Progression suspected

Table 4.4. Treatment of immediate hypersensitivity reactions HES = Hespan

As needed: i.v. line Oxygen

Mandatory: i.v. line Oxygen

P2-Sympathicomime-

tica inhalation Prednisolone (250-500 mg i.v.)

Mandatory: i.v. line Oxygen 2-sympathicomime-tica inhalation Prednisolone (0.5-1 g i.v.)

As needed: i.v. line Oxygen

Mandatory: i.v. line Oxygen

Colloids, Ringer solution, HES

Mandatory: i.v. line Oxygen

Colloids, Ringer solution, HES Adrenaline 0.1 mg i.v. repeated every 3 min

From Kemp 2002

Cardiopulmonary Resuscitation and intubation

Corticoids i.v. H1-(+H2-) antagonists

Corticoids i.v. H1-(+H2-) antagonists Adrenaline 0.1 mg i.v.

Corticoids i.v. H1-(+H2-) antagonists Adrenaline 0.1 mg i.v. Dopamine and/or nor-adrenaline as needed

Grade of reaction

What to do?

Grade I (slight to 1 moderate general 2 reaction) 3

Grade II (severe l general reaction) 8 9 10

Grade III (life threatening general reaction)

11 12 13

Stop the cause, stop the antigen Give oxygen by mask (6-10 l/min)

Place an i.v. line and apply volume (500 ml saline, Ringers solution or HES) Measure blood pressure and pulse rate Elevate patient's legs if hypotensive

Inject an Hl-antagonist i.v. (e.g., diphenhydramine 25-50 mg, clemastine 4 mg or dimetindene maleat 8 mg) Optionally inject an H2-antagonist (e.g., cimetidine 400 mg or ranitidine 100 mg)

Call resuscitation team

Give corticosteroids i.v. (e.g., prednisolone 500-1,000 mg) Give adrenaline 1:1000 i.m. (0.2-0.5 mg) In case of bronchospasm give 2-sympathicomimetica (e.g., fenoterol inhalation 100-200 |g orterbutaline0.25-0.5 mg SC)

ECG monitoring

Give adrenaline 1: 1,000 i.v. (0.1 mg, repeated every 3 min) Cardiopulmonary resuscitation and intubation

Table 4.5. Step-by-step algorithm for the treatment of anaphylactic reactions in correlation to the grade of anaphylactic reaction

See also Table 4.4

• Antihistamines (H1 andH2)

• Corticoids

A step-by-step algorithm on what to do with a patient presenting with an anaphylactic reaction is provided in Table 4.5.

Treatment for anaphylaxis is supportive and includes epinephrine/adrenaline as the first-line pharmacological agents. An incidence of 6 % for a biphasic anaphylactic reaction in pediatric patients was reported. A delay in administering epinephrine was associated with increased incidence of biphasic reactions, and unavailability of epinephrine was associated with death (Lee and Greenes 2000; Chiu and Kelly 2005).

Therefore, patients with an anaphylactic reaction need continuous surveillance for 24 h in hospital. This is also necessary in patients with a good reaction to appropriate therapy because of the possibility of recurrence and the delayed reaction (up to12h after the initial reaction) with arrhythmia, myocardial ischaemia or respiratory insufficiency (Haupt 1995).

Monitoring vital functions must include continuous ECG monitoring, pulse oximetry, and blood pressure monitoring.

Management of anaphylactic shock in general is described in great detail by Kemp and Lockey (2002) and is analogous to the management of the immediate reactions to contrast media (Table 4.8).

Guidelines for the management of the cardiovascular shock are published by the American Heart Association (Cummins and Hazinski 2000), the British Resuscitation Council, and the National Guideline Clearinghouse of the United States (NGC) (for addresses of the websites, see Sect. 4.10).

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