Safety of a Powder-free Latex Allergy Protocol in the Operating Theatre: A Prospective, Observational Cohort Study

Introduction

Allergic reactions to natural rubber latex( NRL, or Latex) are an important issue in daily anesthesia practice. Latex allergy may result in lesions consistent with irritation dermatitis and type 4 allergic contact dermatitis. But it may also result in type 1 allergic reactions which are potentially lethal.(1) The prevalence of latex allergy in a general population is estimated less than 1%, but sensitization can rise up to 5.4-7.6%.(3,4) In certain populations at risk, the prevalence of latex allergy and sensitization rises up to 17% in health care workers an even 73% in patients who were exposed to latex on a regular basis( eg. Patients with spina bifida).

These patients require special logistic and organizational requirements during their stay in the operating room. Nowadays, both guidelines from the Belgian Society of Anesthesiology and Resuscitation(BVAR-SARB) as the American Association of Anesthesiologists recommend these patients to be scheduled as the first case of the day.(1,3) In this way, these patients are treated in an environment with a minimal amount of airborne latex particles. After all, studies have proven that using powdered latex gloves causes a substantial contamination of the operating room. Latex particles can even remain airborne up to 5 hours afterwards.(1,3,5).

In consequence, the guidelines mentioned earlier dictate patients with a (high risk for) latex allergy to be treated in an operating theatre left unused during at least 3 to 6 hours.(1,2,6) Of course, such requirements can result in organizational problems potentially resulting in delaying procedures, financial losses, patient discomfort and dissatisfaction with both patients as well as hospital staff.

The last years, some professionals have suggested the idea that planning these patients as first case of the day is no longer necessary because of certain technical evolutions in current operating room practice.(7) In a guideline published by the Australasian Society of Clinical Immunology and Allergy (last updated March 2010), patients at risk or with known latex allergy are no longer scheduled as first case of the day. However, this requires the removal of all powdered latex gloves from the OR (including pre-anesthesia unit, operating theatres, post anesthesia care unit and surroundings).(8) The requirement for a completely latex free environment en materials when operating on a actual patient with (suspected) latex allergy remains unchanged.

Although several studies have shown the importance of powdered gloves in the spread of airborne latex particles and the basis for this protocol seams acceptable and logical, there is currently no literature confirming the safety of this practice in a clinical setting.

Study objective

Primary objective:

This study wants to evaluate the safety of a latex safe protocol as proposed by the Australasian Society of Clinical Immunology and Allergy. In other words,the investigators hope to demonstrate that patients with known latex allergy or latex sensitisation can be treated safely in operating theatres without special requirements towards scheduling provided that all powdered latex gloves are removed from the OR environment (preparation rooms, theatres, recovery room and surroundings). In contrast, earlier guidelines require the theatre to be left unused during at least 3 hours before a patient with suspected latex allergy can be operated on in this theatre.

Secondary objectives:

• The investigators want to evaluate to what extend patients who report a latex allergy show risk factors of latex allergy.
• To investigate to what extend latex allergy was proven by laboratory testing or skin testing in patients who report a latex allergy.
• Type of latex allergic reaction when patients report a latex allergy.
• The level of satisfaction of surgeons and OR scheduling staff with the new latex safe protocol and with the switching to powder free latex gloves.

Study procedure

Pre-operative setting:

Medical history, including allergies of every patient will be assessed . Every patient with (suspected) latex allergy who will undergo surgery will be approached to participate in this study. There are no restrictions regarding type of surgery.

The research team will ask all eligible patients to sign an informed consent. The researchers will ask all patients who are willing to participate to complete a short questionnaire.

Patients refusing to participate will be treated by the same protocol. However, they will not be contacted in order to provide further medical data in relation to this study.

During the stay in the OR:

Nursing staff and the anesthesiologist perform a time-out procedure prior to surgery. A (suspected) latex allergy is marked in the electronic case file. The software registers this cases and sends a confirmation to the research team.

At the end of the procedure, the anesthesiologist marks if a latex allergic reaction has occurred through a pop -up in the electronic case file.

Post-operative setting:

• Recovery room: Continuation of the latex safe protocol. When the patient is discharged to the ward, a pop-up in the electronic case file asks if any type of latex allergic reaction has occurred.

The patient receives a short note, explaining that the research team will contact him/her after 72 hours.

• Wards/ discharge from hospital: The research team will contact every patient who was marked latex allergic 72 hours after their surgery to answer the questionnaire about any allergic reaction to latex( by phone or in person).

Types of latex reactions:

1. Irritation dermatitis: a non-allergic reaction of the skin to an irritans. Lesions are limited to the area of contact and may occur minutes to hours after exposure. Symptoms include itching, erythema, a burning sensation, blistering, flakiness and fissuring of the skin. This type of reaction is never life-threatening.(1,3,6)
2. Allergic contact dermatitis or delayed cell- mediated hypersensitivity reaction or type 4 reaction: T- cell mediated sensitivity for chemical additives absorbed by the skin. Lesions occur after 6 to 48 hours following exposure and peak after 48 to 72 hours. The lesions may exceed the contact area and consist of itching, erythema, blistering or flakiness.( Symptoms often resemble those of irritation dermatitis.)(1,3,6)
3. IgE mediated immediate hypersensitivity( type 1 reaction:

Based on B-cell mediated production of IgE (immunoglobulin E) antibodies towards Hev b latex proteins after a first exposure. Symptoms already occur after a few minutes up to 1 hour, depending of the route of exposure (inhalation, parenteral or mucous membrane exposure). The severity of the reaction also varies in relation to the route of exposure. Type 1 allergic reactions in response to latex exposure may be lethal.(1,2,3)

Note:

• If the research team( or in daily practice: the attending physician) suspects a latex allergic reaction during the study period , they will determine RIA(radioimmunoassay) - tryptase in case of an anaphylactic reaction. Furthermore, the patient will be referred to an allergy consultant for skin prick test in order to confirm a possible latex allergy.

Satisfaction about the newly implemented protocol:

Starting from 01-02-2016, the research team will investigate the level of satisfaction about the newly implemented protocol by means of a short questionnaire( written or E-mail) sent to all involved surgeons and OR scheduling staff.

With this questionnaire, the investigators want to evaluate

• general satisfaction regarding the new protocol by means of a numeric rating scale ranging from 0 (very unsatisfied) up to 10 (very satisfied).
• whether this new protocol has simplified the OR schedule. The investigators will do so by means of a numeric rating scale ranging from 0 (not true at all) up to 10(absolutely true).
• the level of satisfaction regarding the new type of surgical gloves in case the surgeon had to switch.The investigators will do so by means of a numeric rating scale ranging from 0 (very unsatisfied) up to 10 (very satisfied).