2026-01-20 相關筆記連結
1.
anaphylaxis 嚴重全身性過敏反應 治療藥物與頻次劑量2.
野外與登山醫學---對磺胺類藥物過敏的人可否服用丹木斯3.
anaphylaxis 全身性嚴重過敏反應 腎上腺素劑量4.
名詞翻譯~ Anaphylaxis 全身性嚴重過敏反應5.
anaphylaxis 全身性嚴重過敏反應 診斷標準與治療6.
野外與登山醫學-epipen 腎上腺素筆-全身性嚴重過敏反應治療用藥7.
全身性嚴重過敏反應-Fatal anaphylaxis 死亡案例接觸過敏原之後出現症狀的時間 from uptodate
這篇是 (May 2021 英國)全身性嚴重過敏反應治療指引
重點建議
1. 全身性嚴重過敏反應是會危及生命的過敏反應
2. 辨識是否為全身性嚴重過敏反應可依據
a. 突然快速的症狀進展
b. 會出現呼吸道, 呼吸, 或循環問題
c. 皮膚或黏膜異常, 潮紅, 蕁麻疹, 血管性水腫, 有20%個案不會出現這些
當個案暴露於已知的過敏原之後出現以上症狀, 可能是全身性嚴重過敏反應
可以參照 ABCDE步驟處理危及生命的問題
Airway, Breathing, Circulation, Disability, Exposure (ABCDE)
當ABC出現問題, 第一線治療藥物是腎上腺素, 以肌肉注射方式施打在大腿前外側
若施打一次的五分鐘內沒反應., 可施打第二次
Key recommendations for clinical practice
• Anaphylaxis is a potentially life-threatening allergic reaction.
• Recognise anaphylaxis based on:
1. sudden onset and rapid progression of symptoms
2. Airway and/or Breathing and/or Circulation problems
3. skin and/or mucosal changes (flushing, urticaria, angioedema) –
but these may be absent in up to 20% of cases.
The diagnosis is supported if a patient has been exposed to an allergen known to affect them.
• Treat life-threatening features, using the Airway, Breathing, Circulation,
Disability, Exposure (ABCDE) approach.
• Adrenaline is the first-line treatment for anaphylaxis. Give intramuscular (IM)
adrenaline early (in the anterolateral thigh) for Airway/Breathing/Circulation
problems.
*** A single dose of IM adrenaline is well-tolerated and poses minimal
risk to an individual having an allergic reaction. If in doubt, give IM
adrenaline.
*** Repeat IM adrenaline after 5 minutes if Airway/Breathing/Circulation
problems persist.
• Intravenous (IV) adrenaline must be used only in certain specialist
settings, and only by those skilled and experienced in its use.
*** IV adrenaline infusions form the basis of treatment for refractory
anaphylaxis: seek expert help early in patients whose respiratory and/or
cardiovascular problems persist despite 2 doses of IM adrenaline.
• Follow the National Institute for Health and Care Excellence (NICE) guideline
for the assessment and referral of patients suspected to have had
anaphylaxis. Specifically:
*** All patients should be referred to a specialist clinic for allergy
assessment.
*** Offer patients (or, if appropriate, their parent and/or carer) an
appropriate adrenaline injector as an interim measure before the
specialist allergy assessment (unless the reaction was druginduced).
*** Patients prescribed adrenaline auto-injectors (and/or their
parents/carers) must receive training in their use, and have an
emergency management or action plan
• Further research is needed to better identify and treat patients at greatest risk of severe anaphylaxis.
*** Anaphylaxis reactions should be reported to the UK Anaphylaxis
Registry at www.anaphylaxie.net (to register, email
anaphylaxis.registry@ic.ac.uk).
*** Follow guidance for reporting and debriefing of adverse events.
Summary of changes from previous guideline
This guideline replaces the previous guideline from Resuscitation Council UK (RCUK):
Emergency treatment of anaphylactic reactions – Guidelines for healthcare providers
(originally published January 2008, annotated July 2012 with links to NICE guidance).
• Greater emphasis on intramuscular adrenaline to treat anaphylaxis, and repeated
after 5 minutes if Airway/Breathing/Circulation problems persist.
• A specific dose of adrenaline is now included for children below 6 months of
age.
• Increased emphasis on the importance of avoiding sudden changes in posture
and maintaining a supine position (or semi-recumbent position if that makes
breathing easier for the patient) during treatment.
• There are 2 algorithms:
*** Initial treatment of anaphylaxis, with emphasis on repeating the dose
of adrenaline after 5 minutes and giving an IV fluid bolus if
Airway/Breathing/Circulation problems persist.
*** Treatment of refractory anaphylaxis, defined as anaphylaxis where
there is no improvement in respiratory or cardiovascular symptoms
despite two appropriate doses of IM adrenaline.
• IV fluids are recommended for refractory anaphylaxis, and must be given
early if hypotension or shock is present.
• Antihistamines are considered a third-line intervention and should not be used to
treat Airway/Breathing/Circulation problems during initial emergency treatment.
*** Non-sedating oral antihistamines, in preference to chlorphenamine,
may be given following initial stabilisation especially in patients with
persisting skin symptoms (urticaria and/or angioedema).
• Corticosteroids (e.g. hydrocortisone) are no longer advised for the routine
emergency treatment of anaphylaxis.
• New guidance is offered relating to the duration of observation following
anaphylaxis, and timing of discharge.
1. Introduction
1.1 Purpose of this guideline
Increasing numbers of people are presenting to UK hospitals with anaphylaxis.
4,5 Despite
previous guidelines, at least 50% of reactions are not treated with IM adrenaline (the firstline treatment of anaphylaxis)6 and treatment, investigation and follow-up of patients with
anaphylaxis is suboptimal.
This guideline replaces the previous guideline from Resuscitation Council UK: Emergency
treatment of anaphylactic reactions – Guidelines for healthcare providers (originally
published January 2008, annotated July 2012 with links to NICE guidance).1 There are no
randomised controlled clinical trials in humans providing unequivocal evidence for the
optimal treatment of anaphylaxis; such evidence is unlikely to be forthcoming.11,12
Nonetheless, the evidence-base for specific management strategies has increased, and
international guidelines have been updated.
This guideline provides:
• an updated consensus about the recognition and treatment of anaphylaxis in all
healthcare settings
• a focus on the treatments that patients with anaphylaxis should receive, that are
relevant to all healthcare providers
• recommendations for treatment that are easy to implement, and that will be
appropriate for most anaphylaxis reactions
• new guidance on the treatment of refractory anaphylaxis.
This guideline does not cover every possible anaphylaxis scenario, and has been written to
be as simple as possible to facilitate teaching, learning and implementation. Improved
implementation should reduce harm and deaths from anaphylaxis.
1.2 略
1.3 Key points
Treatment of anaphylaxis should be based on general life-support principles:
• Call for help early.
• Use the Airway, Breathing, Circulation, Disability, Exposure (ABCDE) approach to
recognise and treat problems. Treat the greatest threat to life first.
• Give IM adrenaline to treat Airway/Breathing/Circulation problems.
• Initial treatment should not be delayed by a lack of a complete history or definite
diagnosis.
• Repeat IM adrenaline after 5 minutes if features of anaphylaxis do not resolve.
Patients having anaphylaxis in any setting should expect the following as a minimum:
• recognition that they are seriously unwell
• an early call for help (resuscitation team or ambulance)
• initial assessment and treatment based on an ABCDE approach
• prompt treatment with IM adrenaline
• investigation and specialist follow-up in an allergy clinic.
Both IM and IV routes are recommended for the treatment of anaphylaxis in the perioperative setting. IV adrenaline should be used for anaphylaxis only by experienced
specialists in an appropriate setting (e.g. critical care and peri-operative settings). See
Section 5.1.2 for more information.
1.4略
2. Anaphylaxis
2.1 Definition of anaphylaxis
The World Allergy Organisation Anaphylaxis Committee defines anaphylaxis as:
11
"A serious systemic hypersensitivity reaction that is usually rapid in onset and
may cause death.
Severe anaphylaxis is characterized by potentially life-threatening compromise
in airway, breathing and/or the circulation, and may occur without typical skin
features or circulatory shock being present.”
Anaphylaxis is a clinical diagnosis; a precise definition is not important for treatment.
Anaphylaxis is characterised by:
• Sudden onset and rapid progression of symptoms.
• Airway and/or Breathing and/or Circulation problems.
• Usually, skin and/or mucosal changes (flushing, urticaria, angioedema).
The diagnosis is supported if a patient has been exposed to an allergen known to affect
them. However, in up to 30% of cases there may be no obvious trigger.
Remember:
• Skin or mucosal changes alone are not a sign of anaphylaxis.
• Skin and mucosal changes can be subtle or absent in 10–20% of reactions
(e.g. some patients present initially with only bronchospasm or hypotension).
Gastrointestinal symptoms (e.g. nausea, abdominal pain, vomiting) in the absence of Airway
and/or Breathing and/or Circulation problems do not usually indicate anaphylaxis. Abdominal
pain and vomiting can be symptoms of anaphylaxis due to an insect sting or bite.
Anaphylaxis lies along a spectrum of severity in terms of allergic symptoms.11 (Figure 1)
2.2略
2.3 Pathophysiology of anaphylaxis
In anaphylaxis, the activation of multiple inflammatory pathways causes Airway/Breathing/
Circulation problems:
• Tissue oedema and smooth muscle contraction in the airways (causing
bronchospasm and wheeze). This is the most common presentation for food-induced
anaphylaxis.
• Fluid extravasation (tissue oedema, hypovolaemia), and a profound reduction in
venous tone.28,29
*** If severe, this mix of hypovolaemic and distributive shock cannot be
overcome by compensatory mechanisms and combine to cause reduced
blood flow back to the heart and an underfilled ventricles.
29
• Depressed myocardial function has also been reported, which can cause cardiogenic
shock. Electrocardiographic changes have been noted. Release of mediators may
cause arrhythmia such as supraventricular tachycardia; a reduction in coronary
perfusion may cause or contribute to ST-segment or T-wave changes.29
• Fluid leakage into the bowel and smooth muscle contraction (resulting in abdominal
and pelvic cramps).
In a landmark paper, Fisher described 205 adult patients with peri-operative anaphylaxis,
many of whom had central venous monitoring in place.
31 He reported:
• low right-heart filling pressures in all patients without cardiac disease; despite having
elevated pressures, 9 of 11 patients with cardiac disease appeared to need volume
expansion to achieve a stable blood pressure
• increases in haematocrit in 22 patients were indicative of extravasation of up to
35% of circulating blood volume within 10 minutes of reaction onset.
These data emphasise the need for aggressive fluid resuscitation in anaphylactic shock.
Changes in posture from supine to standing or sitting upright have been associated with
cardiovascular collapse and death during anaphylaxis.32,33 The change in posture further
reduces venous return to the heart; this can lead to a further reduction in cardiac output and
can compromise myocardial perfusion.
Keeping a patient with cardiovascular instability flat, with or without
the legs raised, will maximise venous return to the heart and is
therefore a key component of the initial response to anaphylaxis (see
section 4.3). Patients with predominantly respiratory symptoms (and no
evidence of cardiovascular instability) may prefer to be in a semi-recumbent
position. Pregnant patients should lie on their left side to prevent aortocaval
compression, if necessary, with the bed in a head-down position (see
Section 4.7).
3. Recognition of anaphylaxis
Look for:
• Sudden onset of Airway and/or Breathing and/or Circulation problems.
• Usually, skin and/or mucosal changes (flushing, urticaria, angioedema).
Skin or mucosal changes alone are not a sign of anaphylaxis and may be absent in up to
20% of reactions.
Confusion may arise because some patients have systemic reactions that are not
anaphylaxis. Generalised urticaria, angioedema, and rhinitis are not considered to be
anaphylaxis because life-threatening features – an Airway and/or Breathing and/or
Circulation problem – are not present. However, if in doubt, give IM adrenaline and seek
expert help.
Most reactions develop quickly over minutes: the timing is dependent on the trigger (see
Table 2 and Figure 4). Allergens given by a parenteral route (e.g. IV drug, intramuscular
injection, insect sting) cause a more rapid onset of symptoms than reactions to an ingested
food or drug.
Different symptoms are often associated with different triggers, as shown in Table 2. Most
anaphylaxis in children is due to food, which may explain why respiratory presentations of
anaphylaxis are more common in this age group. In around 5 -10% cases, no obvious trigger
can be identified.
3.2 Airway / Breathing / Circulation problems
Patients can have either an A or B or C problem, or any combination. Use the ABCDE
approach to recognise these and treat early.
Airway problems
Airway swelling
(throat and tongue
swelling causing difficulty
in breathing/swallowing;
patients may feel their
throat is closing)
• Hoarse voice
• Stridor (a high-pitched
inspiratory noise caused
by upper airway
obstruction)
Breathing problems
• Increased work of
breathing
• Bronchospasm (wheeze)
and/or persistent cough
• Patient becoming tired
with the effort of breathing
(fatigue)
• Hypoxaemia
(SpO 2 <94%) which may
cause confusion and/or
central cyanosis
• Respiratory arrest
Circulation problems
• Signs of shock:
o pale, clammy
o significant tachycardia
(increased heart rate)
o hypotension
(low blood pressure)
• Dizziness, decreased
conscious level or loss of
consciousness
• Arrhythmia
• Cardiac arrest
Breathing problems can vary from mild bronchospasm to life-threatening asthma with no
other features to suggest anaphylaxis.42 Anaphylaxis can present primarily as respiratory
arrest.19,22,27 Consider anaphylaxis in a person with sudden onset breathing difficulties,
especially if known to be allergic to a food or insect sting.
Circulation problems (often referred to as anaphylactic shock) can be caused by
vasodilation, by capillary leak with loss of fluid from the circulation, and by direct myocardial
depression (see Figure 5). Characteristically, these cause a compensatory tachycardia.20,29
Bradycardia (a slow heart rate) is usually a late feature, often preceding cardiac arrest,
29 but
has also been reported in insect/venom anaphylaxis, occurring with the onset of
hypotension.44
Anaphylaxis can also cause myocardial ischaemia and electrocardiogram
(ECG) changes,31 even in individuals with normal coronary arteries.43
Anaphylaxis can also affect a patient’s neurological status (Disability problems) because of
decreased brain perfusion or the effect of local allergic mediators in the central nervous system. There may be confusion, agitation and loss of consciousness. Patients are usually
anxious and may experience a “sense of impending doom”.45
Patients may also have gastrointestinal symptoms (abdominal pain, incontinence, vomiting).
These symptoms are more likely to indicate anaphylaxis in the context of reactions due to
insect bite or sting, snake bite or parenteral administration of drugs.
3.3 Skin and/or mucosal changes
These are assessed as part of the Exposure when using the ABCDE approach.
• These are often the first feature of allergic reactions and are present in over 80% of
anaphylaxis.37
• They can be subtle (e.g. patchy erythema) or dramatic (generalised rash).
• They may involve the skin, the mucosal membranes (e.g. lips), or both.
• There may be urticaria (also called hives, nettle rash, weals or welts), which can
appear anywhere on the body. Weals may be pale, pink or red, can be different
shapes and sizes, and are often surrounded by a red flare. They are usually itchy.
• Angioedema involves swelling of deeper tissues, most commonly in the eyelids and
lips, and sometimes the tongue and in the throat.
Although skin changes can be worrying or distressing for patients and those treating them,
skin changes without life-threatening Airway/Breathing/Circulation problems are not
anaphylaxis. Reassuringly, most patients who present with skin changes caused by an
allergic reaction do not go on to develop anaphylaxis.
3.4 Differential diagnosis
• Following an ABCDE approach will help with treating the differential diagnoses.
• In all of the circumstances below, IM adrenaline is unlikely to cause harm and might
be clinically useful.
Life-threatening conditions:
• Sometimes anaphylaxis can present with symptoms and signs that are very similar to
life-threatening asthma – this is most common in children.
• Hypotension is a late sign in children.
• Seek expert help early if there are any doubts about the diagnosis and treatment.
Other conditions which can mimic anaphylaxis (but do not respond to adrenaline):
• inducible laryngeal obstruction (ILO, formerly known as vocal cord dysfunction)
• ACE inhibitor-induced angioedema, which can be life-threatening and typically does
not respond to adrenaline.
Non-life-threatening conditions (these usually respond to simple measures):
• faint (vasovagal episode) – this can occur in the context of non-anaphylaxis allergic
reactions (see below)
• panic attack
• breath-holding episode in a child
• spontaneous (non-allergic) urticaria or angioedema.
There may be difficulty distinguishing between anaphylaxis and a panic attack. Patients with
prior anaphylaxis may be prone to panic attacks if they think they have been re-exposed to
the allergen that caused a previous reaction. The sense of impending doom and
breathlessness leading to hyperventilation are symptoms that can resemble anaphylaxis.
Sometimes, there may be flushing, or blotchy skin associated with anxiety adding to the
diagnostic difficulty.
Diagnostic difficulty may also occur with vasovagal attacks after immunisation or other
procedures, but the absence of rash, breathing difficulties, and swelling are useful
distinguishing features, as is the slow heart rate in a vasovagal attack (whereas anaphylaxis
is usually associated with a tachycardia). Symptoms should resolve rapidly on lying flat.
If rapid recovery does not happen, consider anaphylaxis as a cause.
下圖. 如何鑑別迷走神經反射造成暈厥或全身性嚴重過敏反應
頑固性全身性嚴重過敏反應
多數全身性嚴重過敏反應打一次腎上腺素就會改善. 10% 需打第二劑才有反應. 2.2% 需要施打超過兩次才有反應
4.8 Refractory anaphylaxis
Most of the anaphylaxis reactions occurring in a community setting will respond to initial
treatment with IM adrenaline, although currently around 10% receive a second dose and
2.2% (95% confidence interval, 1.1- 4.1%) receive more than two doses.
6
All healthcare professionals should be able to identify patients with Breathing and/or
Circulation problems of anaphylaxis which do not respond to initial treatment with IM
adrenaline, and to escalate care quickly by calling for support from the resuscitation team or
from the ambulance service for urgent transfer to hospital.
