Clinical Determinants and Perioperative Allergic Reactions (CADECAP Study)
Clinical Determinants and Perioperative Allergic Reactions (CADECAP Study)
The clinical presentation of perioperative allergic and non-allergic clinical reactions is
 often considered undistinguishable while the accurate analysis of clinical cases shows
 striking clinical differences which might be predictive of the etiological diagnosis
 (allergic versus non-allergic).

 The four-step Ring and Messmer clinical scale helps to guide acute management of immediate
 hypersensitivity accordingly to the clinical presentation although this scale does not take
 into account the mechanism involved (i.e. allergic versus non-allergic). Non-allergic
 clinical reactions are usually non-life-threatening and may, sometimes, spontaneously resolve
 in contrast to allergic reactions which are mainly severe and life-threatening conditions,
 typically called anaphylaxis.

 The cornerstones of anaphylaxis management are fluid therapy and epinephrine. However, poor
 outcome has been reported as a result of delayed treatment and/or inappropriate management of
 perioperative anaphylaxis.
The main objectives of this study are to: i) characterize the clinical and paraclinical
 determinants of IgE-mediated allergy that could be correlated to the ultimate diagnosis; and
 ii) elaborate a decision-making algorithm for clinical patterns identification of
 perioperative allergic reactions to guide acute management, thus potentially decreasing the
 related morbidity and mortality.

 The secondary objectives are to: i) suggest a modification of the Ring and Messmer scale
 according to the phenotypes involved; ii) identify the clinical characteristics of isolated
 non-allergic bronchospasm; iii) compare the most frequent agents involved in perioperative
 IgE-mediated allergy to those reported in the international studies; iv) identify the
 negative predictive values of skin tests in allergic and non-allergic patients; v) compare
 the therapeutic modalities used to those recommended in the literature; vi) describe the
 cases of morbidity and mortality and identify the potential risk factors.

 The Ring and Messmer scale is used to quote the clinical features occurring in drug- or
 latex-induced immediate hypersensitivity and has been adapted to the perioperative setting as
 follows:

 Grade I: Muco-cutaneous signs only (generalized erythema and/or extensive urticaria and/or
 angioedema) Grade II: Mucocutaneous signs, hypotension, tachycardia and/or moderate
 bronchospasm Grade III: Mucocutaneous signs, cardiovascular collapse, tachycardia or
 bradycardia, bronchospasm, digestive signs Grade IV: Cardiac arrest Grade V: Death

 Perioperative immediate hypersensitivity reaction requires further allergologic assessment.

 The allergologic assessment is performed a few weeks after the reaction to confirm or
 disprove an allergic mechanism behind the reaction (i.e. allergy versus non-allergy), and to
 identify culprit agent(s) and safe drugs, including suitable alternatives. It is based on the
 review of the details of the reaction along with histamine and/or tryptase levels and
 specific Immunoglobulin E levels (when available) and skin tests results.

 Plasma histamine and/or tryptase levels and Immunoglobulin E levels are measured at the time
 of the reaction. Acute tryptase levels are compared to baseline tryptase measured at least 24
 hours after the reaction or when the patient is referred for allergological investigation.
 Skin tests, including prick-tests and intradermal tests, are performed during the
 allergological assessment.
Inclusion criteria:

 -  Patients having experienced a perioperative immediate hypersensitivity (including the
 obstetrical setting) according to one grade of the Ring and Messmer clinical scale,
 for whom:

 -  The clinical history is known and has been related to perioperative immediate
 hypersensitivity;

 -  The biological assessment including plasma histamine and/or tryptase (and serum IgE
 when available) was performed after the onset of immediate hypersensitivity according
 to current guidelines;

 -  The allergological assessment including skin tests performed by the collaborators of
 this study was carried out according to current guidelines in surviving patients

 Exclusion criteria:

 • Patients who decline to be involved in the study